Patent Description:
<FIG> illustrate an example of a conventional construction of an electric motor with a reverse-input blocking clutch described in <CIT>. The electric motor with the reverse-input blocking clutch <NUM> includes a reverse-input blocking clutch <NUM> in the middle of an output shaft <NUM>. That is, the output shaft <NUM> is configured by connecting a first shaft <NUM> and a second shaft <NUM> coaxially arranged with each other by the reverse-input blocking clutch <NUM>.

The first shaft <NUM> is rotatably supported inside a motor housing <NUM>. A rotor <NUM> is fitted and fixed around an intermediate portion in the axial direction of the first shaft <NUM>, and a stator <NUM> supported and fixed to the motor housing <NUM> is arranged around the rotor <NUM>. When the stator <NUM> is energized and a rotational force is applied to the rotor <NUM>, the first shaft <NUM> rotates.

The second shaft <NUM> is rotatably supported with respect to a clutch housing <NUM> of the reverse-input blocking clutch <NUM>.

The reverse-input blocking clutch <NUM> includes an input portion <NUM>, an output portion <NUM>, the clutch housing <NUM>, and a pair of engaging elements <NUM>. In the following description, regarding the reverse-input blocking clutch <NUM>, one side in the axial direction is the right side in <FIG>, and the other side in the axial direction is the left side in <FIG>.

The input portion <NUM> is provided at an end portion on the other side in the axial direction (left side in <FIG>) of the first shaft <NUM>. The input portion <NUM> has an input shaft portion <NUM> and a pair of input-side engaging portions <NUM>. The input shaft portion <NUM> has a stepped columnar shape. The pair of input-side engaging portions <NUM> is configured by convex portions that extend in the axial direction from two locations on opposite sides in the radial direction of a tip-end surface of the input shaft portion <NUM>.

The output portion <NUM> is provided at an end portion on the one side in the axial direction (right side in <FIG>) of the second shaft <NUM>. The output portion <NUM> has an output-side engaging portion <NUM>. The output-side engaging portion <NUM> has a substantially elliptical columnar shape and is arranged between the pair of input-side engaging portions <NUM>.

The clutch housing <NUM> has a stepped cylindrical shape. That is, the clutch housing <NUM> includes a small-diameter cylindrical portion <NUM> on the other side in the axial direction, a large-diameter cylindrical portion <NUM> on the one side in the axial direction, and a side plate portion <NUM> that connects the small-diameter cylindrical portion <NUM> and the large-diameter cylindrical portion <NUM>. The clutch housing <NUM> has a pressed surface <NUM> on an inner peripheral surface of a portion on the other side in the axial direction of the large-diameter cylindrical portion <NUM>. In other words, the clutch housing <NUM> corresponds to a pressed member.

Further, the clutch housing <NUM> has protruding portions <NUM> protruding toward outside in the radial direction from a plurality of locations in the circumferential direction of an outer peripheral surface of the large-diameter cylindrical portion <NUM> and screw holes <NUM> penetrating the protruding portions <NUM> in the axial direction.

The clutch housing <NUM> is connected and fixed to the motor housing <NUM> by externally fitting an end portion on the one side in the axial direction of the large-diameter cylindrical portion <NUM> to an annular protrusion <NUM> provided at an end portion on the other side in the axial direction of the motor housing <NUM> without looseness, and by screwing bolts inserted into through holes <NUM> provided in the motor housing <NUM> to the screw holes <NUM>. The motor housing <NUM> is supported and fixed to a stationary portion that does not rotate during use.

Each engaging element <NUM> has a substantially semicircular plate shape and is arranged on the inside in the radial direction of the large-diameter cylindrical portion <NUM> of the clutch housing <NUM>. The engaging element <NUM> has a pressing surface <NUM> configured by a partially cylindrical convex surface on an outside surface in the radial direction facing the pressed surface <NUM> and a bottom surface <NUM> configured by a flat surface except for a portion provided with an output-side engaged portion <NUM>, which will be described later, on an inside surface in the radial direction. The radius of curvature of the pressing surface <NUM> is equal to or less than the radius of curvature of the pressed surface <NUM>. The radial direction with respect to the engaging element <NUM> corresponds to a direction orthogonal to the bottom surface <NUM> indicated by an arrow □ in <FIG>, and the width direction with respect to the engaging element <NUM> is a direction parallel to the bottom surface <NUM> indicated by an arrow β in <FIG>.

With the pair of engaging elements <NUM> arranged on the inner side in the radial direction of the large-diameter cylindrical portion <NUM>, the inner-diameter dimension of the large-diameter cylindrical portion <NUM> and the dimension in the radial direction of the engaging elements <NUM> are regulated so that a gap exists in at least one of a portion between the pressed surface <NUM> and the pressing surface <NUM> and a portion between the bottom surfaces <NUM> of the pair of engaging elements <NUM>.

The engaging element <NUM> has an input-side engaged portion <NUM> and the output-side engaged portion <NUM>. The input-side engaged portion <NUM> is configured by a hole that penetrates in the axial direction through a central portion in the radial direction of the engaging element <NUM>, and has a size such that the input-side engaging portion <NUM> may be loosely inserted therein. Therefore, the input-side engaging portion <NUM> is able to displace in a direction of rotation of the input portion <NUM> with respect to the engaging element <NUM>, and the engaging element <NUM> is able to displace in the radial direction of the engaging element <NUM> with respect to the input-side engaging portion <NUM>. The output-side engaged portion <NUM> is configured by a rectangular concave portion that is recessed outward in the radial direction from a central portion in the width direction of the bottom surface <NUM> of the engaging element <NUM>, and has a size such that a front-half portion in a minor axis direction of the output-side engaging portion <NUM> can be arranged therein.

In the assembled state of the reverse-input blocking clutch <NUM>, the pair of input-side engaging portions <NUM> of the input portion <NUM> is inserted from the other side in the axial direction into the input-side engaged portions <NUM> of the pair of engaging elements <NUM>, and the output-side engaging portion <NUM> of the output portion <NUM> is inserted from the one side in the axial direction between the pair of output-side engaged portions <NUM>. In other words, the pair of engaging elements <NUM> is arranged so as to sandwich the output-side engaging portion <NUM> from the outside in the radial direction.

When a rotational torque is input to the first shaft <NUM> by energizing the stator <NUM> and the input portion <NUM> rotates, as illustrated in <FIG>, the input-side engaging portions <NUM> rotate in the direction of rotation of the input portion <NUM> inside the input-side engaged portions <NUM>. Then, inside surfaces in the radial direction of the input-side engaging portions <NUM> press the inner surfaces of the input-side engaged portions <NUM> toward inside in the radial direction, which causes the engaging elements <NUM> move in directions away from the pressed surface <NUM>, in other words, toward inside in the radial direction. Due to this, the pair of output-side engaged portions <NUM> hold the output-side engaging portion <NUM> of the output portion <NUM> from both sides in the radial direction, and the output-side engaging portion <NUM> and the pair of output-side engaged portions <NUM> engage without looseness. As a result, the rotational torque input to the first shaft <NUM> is transmitted to the output portion <NUM> through the pair of engaging elements <NUM> and is output from the second shaft <NUM>.

On the other hand, when a rotational torque is reversely input to the second shaft <NUM> and the output portion <NUM> rotates, as illustrated in <FIG>, the output-side engaging portion <NUM> rotates in the direction of rotation of the output portion <NUM> inside the pair of output-side engaged portions <NUM>. Then, corner portions of the output-side engaging portion <NUM> press the bottom surfaces of the output-side engaged portions <NUM> toward outside in the radial direction, which causes the engaging elements <NUM> move in directions closer to the pressed surface <NUM>, in other words, toward outside in the radial direction. Due to this, the pressing surfaces <NUM> of the engaging elements <NUM> are pressed against the pressed surface <NUM> of the clutch housing <NUM>. As a result, the rotational torque reversely input to the second shaft <NUM> is completely blocked by being transmitted to the clutch housing <NUM> and is not transmitted to the first shaft <NUM>, alternatively, only a part of the rotational torque reversely input to the second shaft <NUM> is transmitted to the first shaft <NUM> and the remaining part is blocked.

In order to completely block the rotational torque reversely input to the second shaft <NUM> so as not to be transmitted to the first shaft <NUM>, the output portion <NUM> is locked by strongly holding the engaging elements <NUM> between the output-side engaging portion <NUM> of the output portion <NUM> and the pressed surface <NUM> of the clutch housing <NUM> so that the pressing surfaces <NUM> do not slide with respect to the pressed surface <NUM>. In order to transmit only a part of the rotational torque reversely input to the second shaft <NUM> to the first shaft <NUM> and block the remaining part, the output portion <NUM> is semi-locked by holding the engaging elements <NUM> between the output-side engaging portion <NUM> and the pressed surface <NUM> so that the pressing surfaces <NUM> slide with respect to the pressed surface <NUM>.

<CIT> describes an electric motor with a reverse input cutoff clutch including a motor housing, an output shaft, a bearing device, a rotor, and a stator.

<CIT> describes a structure of an electric motor with a reverse input cutoff clutch that may easily be downsized.

<CIT> describes a hand operated cranking mechanism to be utilized in conjunction with a lifting apparatus.

In the electric motor with the reverse-input blocking clutch <NUM> described in <CIT>, the clutch housing <NUM> having the pressed surface <NUM> is directly connected and fixed to the motor housing <NUM>. Specifically, the clutch housing <NUM> is connected and fixed to the motor housing <NUM> by screwing the bolts inserted through the through holes <NUM> provided in the motor housing <NUM> into the screw holes <NUM> provided in the protruding portions <NUM> of the clutch housing <NUM>.

When the clutch housing <NUM> is connected and fixed to the motor housing <NUM> by bolts, deformation may occur in the large-diameter cylindrical portion <NUM> of the clutch housing <NUM>, and the roundness of the pressed surface <NUM> provided on the inner peripheral surface of the large-diameter cylindrical portion <NUM> may decrease. If the roundness of the pressed surface <NUM> decreases, the time required for the pressing surfaces <NUM> of the engaging elements <NUM> to come into contact with the pressed surface <NUM> when a rotational torque is reversely input to the second shaft <NUM> may vary depends on the phase of the engaging elements <NUM> with respect to the pressed surface <NUM> in the circumferential direction. That is, variation may occur in the time required to switch the reverse-input blocking clutch <NUM> from the unlocked state to the locked state or semi-locked. As a result, the controllability of the electric motor with the reverse-input blocking clutch <NUM> may deteriorate, and the locking performance of switching the reverse-input blocking clutch <NUM> from the unlocked state to the locked state or the semi-locked state may deteriorate.

<CIT> and <CIT> describe a reverse-input blocking clutch which prevents rotation of an output member by moving engaging elements (rolling bodies) arranged in a space between an inner member and the outer member toward the side having a narrower width in the radial direction of the space and holding the engaging elements strongly between the inner member and the outer member when a rotational torque is reversely input to the output member.

In the reverse-input blocking clutch described in <CIT> and <CIT> as well, when the outer member is directly connected and fixed to a portion that does not rotate during use, the roundness of a pressed surface that is provide on an inner peripheral surface of the outer member and that contacts the engaging elements may deteriorate, resulting in deterioration of controllability and locking performance.

An object of the present invention is to provide a reverse-input blocking clutch capable of preventing deterioration of the roundness of the pressed surface. The present invention is defined by the independent claim. Preferred examples are defined in the dependent claims.

With the reverse-input blocking clutch of one aspect of the present invention, it is possible to prevent the roundness of the pressed surface from deteriorating.

A first example of an embodiment of the present invention will be described using <FIG>.

In the description below, the axial direction, the radial direction, and the circumferential direction refer to, unless stated otherwise, the axial direction, the radial direction, and the circumferential direction of a reverse-input blocking clutch <NUM>, more specifically, of a pressed surface of the pressed member of the reverse-input blocking clutch <NUM> (a pressed surface <NUM> of a housing <NUM>). In this example, the axial direction, the radial direction, and the circumferential direction of the reverse-input blocking clutch <NUM> coincide with the axial direction, the radial direction, and the circumferential direction of an input member <NUM> and the axial direction, the radial direction, and the circumferential direction of an output member <NUM>. Regarding the reverse-input blocking clutch <NUM>, one side in the axial direction is the right side in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>, and the other side in the axial direction is the left side in <FIG>, <FIG>, <FIG>, <FIG>, <FIG>, and <FIG>.

The reverse-input blocking clutch <NUM> of this example includes the input member <NUM>, the output member <NUM>, the housing <NUM> which is the pressed member, and a pair of engaging elements <NUM> as an engaging element. The reverse-input blocking clutch <NUM> transmits rotational torque input to the input member <NUM> to the output member <NUM>, but has a reverse input blocking function that does not transmit rotational torque reversely input to the output member <NUM>, alternatively, transmits only a part of the rotational torque and blocks a remaining part thereof.

The input member <NUM> is connected to an input-side mechanism such as an electric motor, and receives rotational torque. The input member <NUM> of this example has a pair of input-side engaging portions <NUM> as an input-side engaging portion. In a case of implementing the present invention, the input member <NUM> can be configured by combining a plurality of parts, or can be integrally configured as a whole, that is, by one part. In this example, the input member <NUM> is configured by combining a shaft member <NUM> and a pair of input-side engaging pins <NUM>, as illustrated in <FIG>, <FIG>, and <FIG>.

The shaft member <NUM> has an input shaft portion <NUM> and a pair of input arm portions <NUM>.

The input shaft portion <NUM> is configured in a substantially cylindrical shape, and an end portion on the one side in the axial direction thereof is connected to an output portion of the input-side mechanism.

The pair of input arm portions <NUM> extend from an end portion on the other side in the axial direction of the input shaft portion <NUM> toward opposite sides in the radial direction. Each input arm portion <NUM> of the pair of input arm portions <NUM> has a support hole <NUM>, which is an axial through hole, at the intermediate portion in the radial direction.

Each input-side engaging pin <NUM> of the pair of input-side engaging pins <NUM> is configured by a cylindrical pin. An end portion on the one side in the axial direction of the input-side engaging pin <NUM> is pressure fitted and fixed inside the support hole <NUM> of the input arm portion <NUM>. In this example, the input-side engaging portion <NUM> is configured by the intermediate portion in the axial direction and an end portion on the other side in the axial direction of the input-side engaging pin <NUM>.

In this example, the input arm portion and the input-side engaging portion are configured by the pair of input arm portions <NUM> and the pair of input-side engaging portions <NUM> according to the number of engaging elements to be described later, that is, according to the fact that the engaging element is configured by the pair of engaging elements <NUM>. However, in a case of implementing the present invention, the number of the input arm portion and the input-side engaging portion are not limited to two, and it can also be set to one, or three or more, depending on the number of the engaging element.

The output member <NUM> is connected to an output-side mechanism such as a speedreducing mechanism, and outputs rotational torque. The output member <NUM> is arranged coaxially with the input member <NUM>, and has an output-shaft portion <NUM> and an output-side engaging portion <NUM> as illustrated in <FIG> and <FIG>. In a case of implementing the present invention, the output member <NUM> can be configured by combining a plurality of parts, or can be integrally configured as a whole, that is, by one part. In this example, the output member <NUM> is configured by one part.

The output-shaft portion <NUM> is configured in a substantially cylindrical shape, and an end portion on the other side in the axial direction thereof is connected to an input portion of the output-side mechanism.

The output-side engaging portion <NUM> has a substantially elliptical columnar shape, and extends from the central portion of an end surface on the one side in the axial direction of the output-shaft portion <NUM> to the one side in the axial direction. The outer peripheral surface of the output-side engaging portion <NUM>, as illustrated in <FIG>, <FIG>, has side surfaces <NUM> on both sides in the minor axis direction (vertical direction in <FIG>, <FIG>), and guide surfaces <NUM> configured by side surfaces on both sides in the major axis direction (horizontal direction in <FIG>, <FIG>). The guide surfaces <NUM> are arranged on both sides of the side surfaces <NUM>, and in this example, the guide surfaces <NUM> of the side surfaces <NUM> on both sides are continuous in the minor axis direction and are each configured by one curved surface.

Each side surface <NUM> is a flat surface orthogonal to the minor axis direction of the output-side engaging portion <NUM>. Each guide surface <NUM> is a convex curved surface. Specifically, each of the guide surfaces <NUM> is configured by a partially cylindrical convex surface that is centered on the center axis of the output-side engaging portion <NUM> (center axis of the output member <NUM>). Therefore, regarding the output member <NUM>, the outer peripheral surface of a round bar material, for example, can be used for the guide surfaces <NUM>, and the processing cost can be suppressed accordingly. However, in a case of implementing the present invention, each of the guide surfaces may be a partially cylindrical convex surface centered on an axis parallel to the center axis of the output member <NUM>, or may be non-cylindrical shaped convex surface such as partially elliptical shaped convex surface or the like. The output-side engaging portion <NUM> is arranged further on the inner side in the radial direction than the pair of input-side engaging portions <NUM>, and more specifically, is arranged in a portion between the pair of input-side engaging portions <NUM>.

In this example, according to the number of engaging element described later, in other words, according to the fact that the engaging element is configured by the pair of engaging elements <NUM>, the side surface and the guide surfaces arranged on both sides thereof are configured by a pair of side surfaces <NUM> and guide surfaces <NUM> on both sides of each side surface <NUM>. However, in a case of implementing the present invention, the number of the side surface is not limited to two, and it can also be set to one, or three or more, depending on the number of the engaging element.

The housing <NUM>, as illustrated in <FIG> and <FIG>, is formed into a hollow circular disk shape, and is fixed to a fixed member <NUM> that does not rotate during use so that the rotation of the housing <NUM> is restricted. The housing <NUM> is coaxially arranged with the input member <NUM> and the output member <NUM>, and houses the pair of input-side engaging portions <NUM>, the output-side engaging portion <NUM>, the pair of engaging elements <NUM> and the like on the inner side thereof. The housing <NUM> is configured by coupling together an input-side housing element (main housing body) <NUM> arranged on the one side in the axial direction and an output-side housing element (housing cover) <NUM> arranged on the other side in the axial direction by bolts <NUM>.

The input-side housing element <NUM> includes an input-side large diameter tubular portion <NUM> having a cylindrical shape, an input-side small diameter tubular portion <NUM> having a cylidnrical shape, a side plate portion <NUM> having a hollow circular plate shape, and a flange portion <NUM>.

The input-side large diameter tubular portion <NUM> has a pressed surface <NUM> around an inner peripheral surface thereof. That is, in this example, the input-side housing element <NUM> configures a first pressed member element. The pressed surface <NUM> is configured by a cylindrical surface centered on the center axis of the input-side housing element <NUM>.

The input-side large diameter tubular portion <NUM> has an input-side in-row fitting surface <NUM> which configures an inner-diameter-side fitting surface around an outer peripheral surface of an end portion on the other side in the axial direction, which is a portion located on the other side in the axial direction from the flange portion <NUM>. The input-side in-row fitting surface <NUM> is configured by a cylindrical surface centered on the center axis of the input-side housing element <NUM>. The input-side small diameter tubular portion <NUM> has an input-side bearing fitting surface <NUM> in a portion from an end portion on the other side in the axial direction to an intermediate portion in the axial direction of an inner peripheral surface thereof. The input-side bearing fitting surface <NUM> is configured by a cylindrical surface centered on the center axis of the input-side housing element <NUM>. In other words, the pressed surface <NUM>, the input-side in-row fitting surface <NUM>, and the input-side bearing fitting surface <NUM> are arranged coaxially with each other.

The input-side small diameter tubular portion <NUM> is coaxially arranged with the input-side large diameter tubular portion <NUM> on the one side in the axial direction of the input-side large diameter tubular portion <NUM>.

The side plate portion <NUM> has a hollow circular plate-shaped end surface shape when viewed from the axial direction. An end portion on the outside in the radial direction of the side plate portion <NUM> is connected to an end portion on the one side in the axial direction of the input-side large diameter tubular portion <NUM>, and an end portion on the inside in the radial direction of the side plate portion <NUM> is connected to an end portion on the other side in the axial direction of the input-side small diameter tubular portion <NUM>.

The flange portion <NUM> protrudes toward the outer side in the radial direction from an intermediate portion in the axial direction of the input-side large diameter tubular portion <NUM>. The flange portion <NUM> has through holes <NUM> penetrating in the axial direction at a plurality of locations in the circumferential direction. In this example, the flange portion <NUM> has through holes <NUM> penetrating in the axial direction at eight locations in the circumferential direction.

The output-side housing element <NUM> includes a tubular portion <NUM> having a cylindrical shape, an output-side small-diameter tubular portion <NUM> having a cylindrical shape, a side plate portion <NUM> having a hollow circular plate shape, and mounting portions <NUM>. That is, in this example, the output-side housing element <NUM> configures a second pressed member element.

The tubular portion <NUM> has an output-side in-row fitting surface <NUM>, which configures an outer-diameter-side fitting surface, around an inner peripheral surface of a portion on the one side in the axial direction. The output-side in-row fitting surface <NUM> is configured by a cylindrical surface centered on the center axis of the output-side housing element <NUM>. The output-side in-row fitting surface <NUM> has an inner-diameter dimension capable of fitting with the input-side in-row fitting surface <NUM> of the input-side housing element <NUM> without looseness.

Further, the tubular portion <NUM> has screw holes <NUM> opening at an end surface on the one side in the axial direction at a plurality of locations in the circumferential direction that are aligned with the through holes <NUM> of the input-side housing element <NUM>. In this example, the tubular portion <NUM> has screw holes <NUM> opening at the end surface on the one side in the axial direction at eight locations in the circumferential direction that are aligned with the eight through holes <NUM>.

The output-side small-diameter tubular portion <NUM> is arranged coaxially with the tubular portion <NUM> on the other side in the axial direction of the tubular portion <NUM>. The output-side small-diameter tubular portion <NUM> has an output-side bearing fitting surface <NUM> in a portion from an end portion on the one side in the axial direction to an intermediate portion of the inner peripheral surface. The output-side bearing fitting surface <NUM> is configured by a cylindrical surface centered on the center axis of the output-side housing element <NUM>. That is, the output-side in-row fitting surface <NUM> and the output-side bearing fitting surface <NUM> are arranged coaxially with each other.

The side plate portion <NUM> has a hollow circular plate-shaped end surface shape when viewed from the axial direction. An end portion on the outside in the radial direction of the side plate portion <NUM> is connected to an end portion on the other side in the axial direction of the tubular portion <NUM>, and an end portion on the inside in the radial direction of the side plate portion <NUM> is connected to an end portion on the one side in the axial direction of the output-side small-diameter tubular portion <NUM>.

The mounting portions <NUM> are provided at a plurality of locations that are evenly spaced in the circumferential direction. In this example, four mounting portions <NUM> are provided at four locations that are evenly spaced in the circumferential direction. Each mounting portion <NUM> has a protruding portion <NUM> protruding from an outer peripheral surface of the tubular portion <NUM> toward the outside in the radial direction and a mounting hole <NUM> penetrating in the axial direction of the protruding portion <NUM>.

The housing <NUM> is configured by coupling and fixing the input-side housing element <NUM> and the output-side housing element <NUM> together by fitting the input-side in-row fitting surface <NUM> of the input-side housing element <NUM> with the output-side in-row fitting surface <NUM> of the output-side housing element <NUM> without looseness, and screwing the coupling bolts <NUM> that are inserted through the through holes <NUM> respectively into the screw holes <NUM> respectively and further tightening them in a state where the side surface on the other side in the axial direction of the flange portion <NUM> of the input-side housing element <NUM> is in contact with the side surface on the one side in the axial direction of the tubular portion <NUM> of the output-side housing element <NUM>.

In this example, the input-side in-row fitting surface <NUM> and the input-side bearing fitting surface <NUM> of the input-side housing element <NUM> are coaxially arranged with each other, and the output-side in-row fitting surface <NUM> and the output-side bearing fitting surface <NUM> of the output-side housing element <NUM> are coaxially arranged with each other. Therefore, in the assembled state of the housing <NUM> in which the input-side in-row fitting surface <NUM> is fitted without looseness with the output-side in-row fitting surface <NUM>, the input-side bearing fitting surface <NUM> and the output-side bearing fitting surface <NUM> are coaxially arranged with each other.

In this example, the output-side housing element <NUM> is supported by and fixed to the fixed member <NUM> by screwing and further tightening the supporting bolts inserted into the mounting holes <NUM> into screw holes <NUM> provided in the fixed member <NUM>. Due to this, the housing <NUM> is supported by and fixed to the fixed member <NUM>.

In the assembled state of the housing <NUM>, the input shaft portion <NUM> of the input member <NUM> is rotatably supported by an input-side bearing <NUM>, which is an additional component of this example, with respect to the input-side bearing fitting surface <NUM> of the input-side housing element <NUM>. Moreover, the output-shaft portion <NUM> of the output member <NUM> is rotatably supported by an output-side bearing <NUM>, which is an additional component of this example, with respect to the output-side bearing fitting surface <NUM> of the output-side housing element <NUM>. As a result, the input member <NUM> and the output member <NUM> are coaxially arranged with each other, and coaxially arranged with the pressed surface <NUM> of the housing <NUM>. Furthermore, in this state, the pair of input-side engaging portions <NUM> and the output-side engaging portion <NUM> are arranged on the inner side in the radial direction of the pressed surface <NUM> of the housing <NUM>.

Here, regarding the reverse-input blocking clutch <NUM>, in a case where it is desired to increase the performance level of switching from a locked state or semi-locked state (described later) to an unlocked state (lock releasing performance) or the like, it is necessary that the coaxiality and inclination of the input member <NUM> and the output member <NUM> be strictly managed. In such a case, it is possible to apply methods of common bearing usage such as changing both the input-side bearing <NUM> and the output-side bearing <NUM> from single-row rolling bearings as illustrated in the drawings to doublerow rolling bearings. In a case of implementing the present invention, the input-side bearing may be omitted if the coaxiality of the input member with respect to the pressed surface is ensured. Further, the output-side bearing may be omitted if the coaxiality of the output member with respect to the pressed surface is ensured.

Each engaging element <NUM> of the pair of engaging elements <NUM> has a pressing surface <NUM> facing the pressed surface <NUM>, an input-side engaged portion <NUM> that can be engaged with the input-side engaging portion <NUM>, and an output-side engaged portion <NUM> that can be engaged with the output-side engaging portion <NUM>, and is arranged on the inner side in the radial direction of the pressed surface <NUM> so as to move in a first direction which is a direction away from or toward the pressed surface <NUM> (a direction that connects the center axis of the reverse-input blocking clutch <NUM> and the central portion in the circumferential direction of the outer-side surface in the radial direction of the engaging element <NUM>, in other words, vertical direction indicated by arrow α in <FIG>). The engaging element <NUM> includes only one body plate <NUM> having the pressing surface <NUM> and the output-side engaged portion <NUM>. The pair of engaging elements <NUM> are arranged so as to sandwich the output-side engaging portion <NUM> from both sides in the radial direction. In this example, the number of the engaging element <NUM> is two, and each of the engaging elements <NUM> is arranged so as to move in the first direction with respect to the pressed surface <NUM>. However, in a case of implementing the present invention, the number of the engaging element can also be set to one, or three or more, as long as the pressing surfaces <NUM> of the engaging element <NUM> is arranged so as to move in the first direction with respect to the pressed surface <NUM>. Since the relationship between each engaging element <NUM> of the pair of engaging elements <NUM>, the pressed surface <NUM>, the input-side engaging portions <NUM>, and the output-side engaging portion <NUM>, and their functions are common, in the following description, from the view point of simplifying the explanation, only one of the engaging elements <NUM> will be described except for the explanation regarding the arrangement of the engaging elements <NUM>.

In this example, the engaging element <NUM> includes the body plate <NUM>, a pair of link members <NUM>, and a oscillation-support shaft <NUM>.

In this example, the body plate <NUM> has a substantially semi-circular plate shape. In this example, the thickness dimension of the body plate <NUM> is smaller than the dimension in the axial direction of the output-side engaging portion <NUM>. The body plate <NUM> includes a pair of pressing surfaces <NUM> facing the pressed surface <NUM>, an output-side engaged portion <NUM>, and a oscillation-support portion <NUM>.

In this example, the outer peripheral surface of the body plate <NUM> is configured by an outer-side surface in the radial direction that has a convex arc-shape and corresponds to an arc of the body plate <NUM>, and an inner-side surface in the radial direction that has a crank shape and corresponds to a chord of the body plate <NUM>. Note that the radial direction of the body plate <NUM> refers to the vertical direction in <FIG> orthogonal to the chord of the body plate <NUM>, and refers to a direction away from or toward the body plate <NUM> with respect to the pressed surface <NUM>. Moreover, the width direction of the body plate <NUM> refers to the horizontal direction indicated by arrow β in <FIG> that is parallel to the chord of the body plate <NUM>, and refers to a direction orthogonal to both the radial direction of the body plate <NUM> and to the axial direction of the pressed surface <NUM>. In this example, the radial direction of the body plate <NUM> is the direction of movement of the body plate <NUM> of the engaging element <NUM> when moving away from or toward the pressed surface <NUM> and corresponds to the first direction. Furthermore, in this example, the width direction of the body plate <NUM> corresponds to a second direction that is orthogonal to both the first direction and to the axial direction of the pressed surface <NUM>.

The pair of engaging elements <NUM> is arranged on the inner side in the radial direction of the pressed surface <NUM> in a state in which the outer-side surfaces in the radial direction of the body plates <NUM> are faced toward the opposite sides and the inner-side surfaces in the radial direction of the body plates <NUM> are faced to each other. The inner-diameter dimension of the pressed surface <NUM> and the dimension in the radial direction of the body plates <NUM> are regulated so that gaps exist, in this state, in at least either of a portion between the pressed surface <NUM> and the outer-side surface in the radial direction of each of the body plates <NUM> and a portion between the inner-side surfaces in the radial direction of the body plates <NUM> that allow the body plates <NUM> to move in the radial direction.

The pair of pressing surfaces <NUM> is provided at two locations so as to be separated in the circumferential direction of the outer-side surface in the radial direction of the body plate <NUM>. The pair of pressing surfaces <NUM>, in the locked state or semi-locked state of the output member <NUM>, is a portion that is pressed against the pressed surface <NUM>. The pair of pressing surfaces <NUM> protrudes further toward the pressed surface <NUM> than portions of the outer-side surface in the radial direction of the body plate <NUM> that are separated from the pair of pressing surfaces <NUM> in the circumferential direction. Each of the pressing surfaces <NUM> is configured by a convex surface having a partially cylindrical shape and having a radius of curvature that is smaller than a radius of curvature of the pressed surface <NUM>. A portion of the outer-side surface in the radial direction of the body plate <NUM> that is located between the pair of pressing surfaces <NUM> in the circumferential direction is a non-contact surface that does not come in contact with the pressed surface <NUM>.

The output-side engaged portion <NUM> is configured by a concave portion provided on a side surface of the body plate <NUM> that is farther from the pressed surface <NUM>. More specifically, the output-side engaged portion <NUM> is configured by a concave portion having a substantially rectangular shape that is recessed outward in the radial direction at a central portion in the width direction of the inner-side surface in the radial direction of the body plate <NUM>. The pair of engaging elements <NUM> is, as illustrated in <FIG>, arranged so as to sandwich the output-side engaging portion <NUM> from the outer sides in the radial direction by the output-side engaged portions <NUM> thereof.

The output-side engaged portion <NUM>, as illustrated in <FIG>, <FIG>, has a size such that a front-half portion in the minor axis direction of the output-side engaging portion <NUM> can be arranged on the inner side thereof. The front-half portion in the minor axis direction of the output-side engaging portion <NUM> corresponds to, as in <FIG> for example, the upper half of the output-side engaging portion <NUM> with respect to the engaging element <NUM> arranged on the upper side and the lower half of the output-side engaging portion <NUM> with respect to the engaging element <NUM> arranged on the lower side. In particular, in this example, as illustrated in <FIG> and <FIG>, the output-side engaged portion <NUM> has an inner surface shape that coincides with the outer peripheral surface of the front-half portion in the minor axis direction of the output-side engaging portion <NUM>.

The inner surface of the output-side engaged portion <NUM> has a bottom surface <NUM> and a pair of guided surfaces <NUM> arranged on both sides of the bottom surface <NUM>. The bottom surface <NUM> is configured by a flat surface that is orthogonal to the radial direction of the body plate <NUM>. Of the inner surface of the output-side engaged portion <NUM>, the guided surfaces <NUM> are arranged on end portions on both sides in the width direction of the body plate <NUM>, and face each other in the width direction. The guided surfaces <NUM> are configured by concave curved surfaces that are inclined in directions such that the distance between the guides surfaces <NUM> increases as going toward the inner side in the radial direction of the body plate <NUM>, or in other words, as going in a direction in the radial direction of the body plate <NUM> away from the pressed surface <NUM>.

The guided surfaces <NUM> are able to come in contact with the guide surfaces <NUM> of the output-side engaging portion <NUM>, and are configured by concave surfaces respectively having a partially cylindrical shape that has a radius of curvature that is the same as that of the guide surface <NUM>, or have a radius of curvature that is slightly larger than that of the guide surface <NUM>. In other words, in this example, as illustrated in <FIG> and <FIG>, the output-side engaged portion <NUM> has an inner-surface shape that coincides with the outer peripheral surface of the front-half portion in the minor axis direction of the output-side engaging portion <NUM>. That is, the bottom surface <NUM> of the output-side engaged portion <NUM> can be brought into surface contact with the side surface <NUM> of the output-side engaging portion <NUM>, and the guided surfaces <NUM> of the output-side engaged portion <NUM> can be brought into surface contact with the guide surfaces <NUM> of the output-side engaging portion <NUM>. Note that in a case of implementing the present invention, the guided surfaces may be configured by non-cylindrical shaped concave surfaces such as partial elliptical tubular shape or the like.

The oscillation-support portion <NUM> is provided in an outer-side portion in the radial direction of the central portion in the width direction of the body plate <NUM>. The oscillation-support portion <NUM> is a portion that oscillatably supports the link member <NUM> through the oscillation-support shaft <NUM>. In this example, the oscillation-support portion <NUM> is configured by a circular hole corresponding to a plate-side through hole passing through in the axial direction of an outer-side portion in the radial direction of the central portion in the width direction of the body plate <NUM>.

The body plate <NUM> further includes an insertion hole <NUM> in an inner-side portion in the radial direction of the central portion in the width direction. The insertion hole <NUM> is configured by an arc-shaped long hole that penetrates in the axial direction through the inner-side portion in the radial direction of the central portion in the width direction of the body plate <NUM>, and that extends in the circumferential direction. The input-side engaging portion <NUM> is inserted into the insertion hole <NUM>. The insertion hole <NUM> has a size that allows the input-side engaging portion <NUM> to be loosely inserted therein. Specifically, when the input-side engaging portion <NUM> is inserted into the inner side of the insertion hole <NUM>, a gap in the circumferential direction and a gap in the radial direction of the body plate <NUM> exist between the input-side engaging portion <NUM> and the inner surface of the insertion hole <NUM>. Therefore, the input-side engaging portion <NUM> is able to displace in the direction of rotation of the input member <NUM> with respect to the insertion hole <NUM> (body plate <NUM>) due to the existence of the gap in the circumferential direction, and the insertion hole <NUM> (body plate <NUM>) is able to displace in the radial direction of the body plate <NUM> with respect to the input-side engaging portion <NUM> due to the existence of the gap in the radial direction of the body plate <NUM>. In other words, the size of the insertion hole <NUM> is regulated so that operation is not hindered due to interference between the inner peripheral edge of the insertion hole <NUM> and the input-side engaging portion <NUM> during operation of the reverse-input blocking clutch <NUM> which will be described later.

As particularly illustrated in <FIG>, the body plate <NUM> has first convex portions <NUM> protruding toward the inner side in the radial direction at locations sandwiching the output-side engaged portion <NUM> from both sides in the width direction in the central portion in the width direction of the inner-side surface in the radial direction of the body plate <NUM>. The body plate <NUM> has second convex portions <NUM> protruding toward the inner side in the radial direction in portions on both sides in the width direction of the inner-side surface in the radial direction of the body plate <NUM>, which are located on the outer side in the width direction of the first convex portions <NUM>.

The pair of link members <NUM> is arranged so as to sandwich the body plate <NUM> from both sides in the axial direction so as to be adjacent to the body plate <NUM> in the axial direction. However, in a case of implementing the present invention, it is also possible to arrange only one link member on only one side in the axial direction of the body plate <NUM>.

Each of the link members <NUM> is a press-molded part that is made by punching a metal plate such as steel plate or the like by press working, and has a substantially rectangular or substantially oblong plate shape. The link member <NUM> has an input-side engaged portion <NUM> in an inner-side portion in the radial direction of the body plate <NUM>, which is a portion on one side in the lengthwise direction of the link member <NUM>, and has a oscillation-supported portion <NUM> in an outer-side portion in the radial direction of the body plate <NUM>, which is a portion on the other side in the lengthwise direction of the link member <NUM>. Particularly, in the construction of this example, the link members <NUM> has a long hole <NUM> that extends in the lengthwise direction. The input-side engaged portion <NUM> is configured by an end portion on the one side in the lengthwise direction of the long hole <NUM>. The oscillation-supported portion <NUM> is configured by a link-side through hole which is an end portion on the other side in the lengthwise direction of the long hole <NUM>. However, in a case of implementing the present invention, it is also possible to configure the input-side engaged portion by a circular hole passing through in the axial direction of the link member, and to configure the oscillation-supported portion by a link-side through hole which is a circular hole passing through in the axial direction of the link member.

The input-side engaging portion <NUM> is inserted through the input-side engaged portion <NUM>. As a result, the portion on the one side in the lengthwise direction of the link member <NUM> is oscillatably connected to the input-side engaging portion <NUM>.

The oscillation-support shaft <NUM> has a cylindrical shape, and is inserted through the oscillation-support portion <NUM> of the body plate <NUM> and the oscillation-supported portion <NUM> of the link member <NUM>. As a result, the portion on the other side in the lengthwise direction of the link member <NUM> is oscillatably supported by the oscillation-support portion <NUM> of the body plate <NUM> through the oscillation-support shaft <NUM>. In this example, the central portion in the axial direction of the oscillation-support shaft <NUM> is fitted with a loose fit into the oscillation-support portion <NUM> of the body plate <NUM> so as to relatively rotate, and portions on both sides in the axial direction are fitted into the oscillation-supported portions <NUM> of the link members <NUM> so as to relatively rotate. The central portion in the axial direction of the oscillation-support shaft <NUM> may also be fitted into the oscillation-support portion <NUM> of the body plate <NUM> by press fitting so as not to relatively rotate.

In a case of implementing the present invention, the oscillation-support portion of the body plate may be configured by a cylindrical protrusion and the oscillation-supported portion of the link member may be configured by a hole into which the cylindrical protrusion is fitted so as to relatively rotate. Alternatively, the oscillation-supported portion of the link member may be configured by a cylindrical protrusion and the oscillation-support portion of the body plate may be configured by a hole into which the cylindrical protrusion is fitted so as to relatively rotate.

In this example, as illustrated in <FIG> and <FIG>, in a state in which the pair of pressing surfaces <NUM> of the engaging element <NUM> comes in contact with the pressed surface <NUM> and the input-side engaging portion <NUM> is located in a central portion in the width direction of the body plate <NUM>, as illustrated in <FIG>, the distance Wa between the edges of the ends of the oscillation-support shafts <NUM> and the input-side engaging portion <NUM> that are on the far sides from each other is set to be equal to or less than the distance Wb between the edges of the ends of the oscillation-supported portion <NUM> and the input-side engaged portion <NUM> that are on far sides from each other (Wa≤Wb). The difference Wb-Wa between the distance Wa and the distance Wb is preferably as large as possible from the viewpoint of simplifying assembly of the reverse-input blocking clutch <NUM>. On the other hand, however, the difference Wb-Wa is preferably as small as possible from the viewpoint of being able to achieve an unlocked state by causing the engaging element <NUM> to immediately move inward in the radial direction when rotational torque is input to the input member <NUM> as will be described later.

The reverse-input blocking clutch <NUM> of this example includes a pair of elastic members <NUM> as an elastic member. In all usage states (operating states) including a neutral state (state illustrated in <FIG>) in which rotational torque is not applied to either the input member <NUM> or the output member <NUM>, each elastic member <NUM> of the pair of elastic members <NUM> is elastically held between the output-side engaging portion <NUM> and the engaging element <NUM> so as to press the output-side engaging portion <NUM> toward the far side from the pressed surface <NUM> in the first direction, in other words, toward the inner side in the radial direction, and presses the engaging element <NUM> toward the side closer to the pressed surface <NUM> in the first direction, in other words, toward the outer side in the radial direction.

That is, in all usage states including the neutral state, the elastic member <NUM> is held between the engaging element <NUM> and the output-side engaging portion <NUM> so that a part (in this example, portions on both sides in the width direction of the body plate <NUM>) is pressed toward the inner side in the radial direction by the engaging element <NUM>, and the other part (in this example, the central portion in the width direction of the body plate <NUM>) is pressed toward the outer side in the radial direction by the output-side engaging portion <NUM>, and the reaction force presses the engaging element <NUM> toward the outer side in the radial direction, and presses the output-side engaging portion <NUM> toward the inner side in the radial direction.

In all usage states including the neutral state, the elastic member <NUM> presses the engaging element <NUM> toward the outer side in the radial direction so as to press the pressing surface <NUM> of the engaging element <NUM> against the pressed surface <NUM>. The reason why the pressing surface <NUM> of the engaging element <NUM> is pressed against the pressed surface <NUM> particularly in the neutral state is to achieve a locked state immediately when rotational torque is reversely input to the output member <NUM>.

The elastic member <NUM> includes elastic pressing portions <NUM> arranged at positions separated on both sides in the axial direction with respect to the output-side engaged portion <NUM> of the body plate <NUM> in the axial direction of the pressed surface <NUM>, and elastically presses the elastic pressing portions <NUM> against the output-side engaging portion <NUM>.

The elastic member <NUM> is not fastened to either the output member <NUM> or the engaging element <NUM>, but is elastically held between the output-side engaging portion <NUM> and the engaging element <NUM>. However, in a case of implementing the present invention, the elastic member may be fastened to the engaging element or may be fastened to the output member. In a case of fastening the elastic member, it is possible to use various conventionally known fastening means such as screws, crimping, adhesion, or the like.

In this example, as illustrated in <FIG>, <FIG>, and <FIG>, the elastic member <NUM> is configured by a leaf spring. The elastic member <NUM> is arranged so as to extend in the width direction of the body plate <NUM> corresponding to the second direction. In this example, the elastic member <NUM> has a crank-shape. In this example, the dimension W<NUM> in the plate width direction (vertical direction in <FIG>) of the elastic member <NUM> is larger than the thickness dimension of the body plate <NUM> and smaller than the dimension in the axial direction of the output-side engaging portion <NUM>.

In this example, the elastic member <NUM> includes support plate portions <NUM>, a pressing plate portion <NUM>, and connecting plate portions <NUM>. The support plate portions <NUM> are configured in a long plate shape and arranged on both side portions in the extending direction of the elastic member <NUM>. The pressing plate portion <NUM> is configured in a long plate shape, is substantially parallel to the support plate portions <NUM>, and is arranged at a central portion in the extending direction of the elastic member <NUM>. The connecting plate portions <NUM> connect end portions of the support plate portions <NUM> and end portions of the pressing plate portion <NUM> that are adjacent to each other in the length direction of the elastic member <NUM>. The connecting plate portions <NUM> are arranged non-parallel to each other, and are inclined in directions away from the pressing plate portion <NUM> in the extending direction of the elastic member <NUM> as going away from the pressing plate portion <NUM> in the plate thickness direction of the support plate portions 51and the pressing plate portion <NUM>.

In a case of implementing the present invention, various shapes may be adopted for the shape of the elastic member according to the arrangement relationship between the engaging element and the output-side engaging portion and the construction of the bottom surface of the engaging element. In other words, various shapes may be adopted for the elastic member as long as the elastic member is elastically held between the output-side engaging portion and the engaging element in all usage states including the neutral state so as to press the output-side engaging portion in the first direction toward the far side from the pressed surface and press the engaging element in the first direction toward the side closer to the pressed surface. In this case, the pressing force applied from the elastic member to the output-side engaging portion may be directed to the far side from the pressed surface in the first direction as a whole, and the pressing force applied from the elastic member to the engaging element may be directed to the side closer to the pressed surface in the first direction as a whole. In other words, as long as these conditions are satisfied, the pressing force applied from the elastic member to each portion of the output-side engaging portion and the pressing force applied from the elastic member to each portion of the engaging element need not be directed in the first direction.

The elastic member <NUM> has a first through hole <NUM> at the central portion in the width direction of the body plate <NUM> (horizontal direction in <FIG>) corresponding to the position aligned with the output-side engaged portion <NUM>, the first through hole <NUM> extending in the width direction and passing through in the radial direction of the body plate <NUM> (front-back direction of the paper in <FIG>, vertical direction in <FIG>) which corresponds to the first direction. In this example, the elastic pressing portions <NUM> are arranged on both sides of the first through hole <NUM> in the axial direction of the pressed surface <NUM> (vertical direction in <FIG>, front-back direction of the paper in <FIG>). In this example, the elastic member <NUM> has second through holes <NUM> that pass through the body plate <NUM> in the radial direction thereof at portions sandwiching the first through hole <NUM> from both sides in the width direction, which correspond to positions separated from the first through hole <NUM> in the width direction of the body plate <NUM> corresponding to the second direction.

In this example, the first through hole <NUM> has a rectangular shape extending in the width direction of the body plate <NUM> as illustrated in <FIG> when viewed in the radial direction of the body plate <NUM>. The first through hole <NUM> is provided so as to pass through the pressing plate portion <NUM>, the connecting plate portions <NUM>, and end potions on the side closer to the pressing plate portion <NUM> of the support plate portions <NUM>. As can be seen from the fact that the first through hole <NUM> is arranged at a position aligned with the output-side engaged portion <NUM>, the first through hole <NUM> is a portion for preventing the elastic member <NUM> from hindering direct engagement between the output-side engaging portion <NUM> and the output-side engaged portion. Each of the second through holes <NUM> has a rectangular shape as illustrated in <FIG> when viewed in the radial direction of the body plate <NUM>. The second through holes <NUM> are provided so as to pass through intermediate portions of the support plate portions <NUM> in the width direction of the body plate <NUM>.

In this example, the elastic member <NUM> is assembled to an inner-side portion in the radial direction of the body plate <NUM>. In this state, the first convex portions <NUM> of the body plate <NUM> are inserted into the first through hole <NUM> of the elastic member <NUM> without looseness, the second convex portions <NUM> of the body plate <NUM> are inserted into the second through holes <NUM> of the elastic member <NUM> without looseness, the outer-side surfaces in the radial direction of the intermediate portions in the plate width direction of the support plate portions <NUM> of the elastic member <NUM> come into contact with portions adjacent to both sides of the second convex portions <NUM> in the width direction of the body plate <NUM> among the inner-side surface in the radial direction of the body plate <NUM>, and both side portions in the plate width direction of the elastic member <NUM> protrude toward both sides in the axial direction of the body plate <NUM>.

In this example, based on the engagement between the elastic member <NUM> and the engaging element <NUM>, in other words, based on engagement between the first through hole <NUM> and the first convex portions <NUM> and engagement between the second through holes <NUM> and the second convex portions <NUM>, displacement of the elastic member <NUM> in a direction orthogonal to the radial direction corresponding to the first direction, in other words, displacement in the axial direction of the pressed surface <NUM> and displacement in the width direction of the body plate <NUM> corresponding to the second direction is regulated. Further, displacement of the elastic member <NUM> toward the outer side in the radial direction is regulated based on the fact that the outer-side surfaces in the radial direction of the support plate portions <NUM> come into contact with portions adjacent to both sides of the second convex portions <NUM> in the width direction of the body plate <NUM> among the inner-side surface in the radial direction of the body plate <NUM>.

In a case of implementing the present invention, displacement of the elastic member <NUM> in a direction orthogonal to the radial direction corresponding to the first direction may also be regulated based on only of the engagement between the first through hole <NUM> and the first convex portions <NUM> and the engagement between the second through holes <NUM> and the second convex portions <NUM>.

The pressing plate portion <NUM> of the elastic member <NUM> is arranged so as to span the output-side engaged portion <NUM> when viewed in the axial direction of the pressed surface. In other words, the intermediate portion in the length direction of the pressing plate portions <NUM> is arranged at the same position as the output-side engaged portion <NUM> in the width direction of the body plate <NUM> corresponding to the second direction. In this example, both side portions in the plate width direction of the pressing plate portion <NUM>, in other words, both side portions of the pressing plate portion <NUM> sandwiching the first through hole <NUM> in the plate width direction corresponds to the pair of elastic pressing portions <NUM>. The pair of elastic pressing portions <NUM> is arranged at portions separated on both sides in the axial direction with respect to the body plate <NUM>. In a free state of the elastic member <NUM>, the pair of elastic pressing portions <NUM> is located on the inner side in the radial direction from the bottom surface <NUM> of the output-side engaged portion <NUM>, and arranged substantially parallel to the bottom surface <NUM>.

Particularly, as illustrated in <FIG>, in the neutral state in which the elastic member <NUM> is arranged between the output-side engaging portion <NUM> and the engaging element <NUM> and no rotational torque is applied to the input member <NUM> and the output member <NUM>, the elastic pressing portions <NUM> come into surface contact with the side surface <NUM> of the output-side engaging portion <NUM> and flexurally deformed toward the outer side in the radial direction slightly. Therefore, the elastic member <NUM> is elastically held between the output-side engaging portion <NUM> and the engaging element <NUM>. As a result, the support plate portions <NUM> elastically press the inner-side surface in the radial direction of the body plate <NUM> toward the outer side in the radial direction and the elastic pressing portions <NUM> elastically press the side surface <NUM> of the output-side engaging portion <NUM> toward the inner side in the radial direction.

As will be described later, when rotational torque is input to the input member <NUM> (see <FIG>) and when rotational torque is reversely input to the output member <NUM> (see <FIG>), the elastic member <NUM> is elastically deformed so as to bend the elastic pressing portions <NUM> toward the outer side in the radial direction, allowing the output-side engaging portion <NUM> and the output-side engaged portion <NUM> to directly engage.

The reverse-input blocking clutch <NUM> of this example includes a reinforcing member <NUM> that spans between tip end portions of the pair of input-side engaging portions <NUM> of the input member <NUM>, in other words, the end portions on the other side in the axial direction of the input-side engaging pins <NUM> of the pair of input-side engaging pins <NUM>.

As illustrated in <FIG>, <FIG>, and <FIG>, the reinforcing member <NUM> has a substantially rectangular plate shape as a whole. The reinforcing member <NUM> includes an insertion hole <NUM> having a substantially oval opening shape in a central portion thereof, and includes support holes <NUM> in portions sandwiching the insertion hole <NUM> from both sides in the minor axis direction of the insertion hole <NUM>.

The output-side engaging portion <NUM> is inserted into the insertion hole <NUM>. The insertion hole <NUM> has a size that allows the output-side engaging portion <NUM> to be loosely inserted. Therefore, the output-side engaging portion <NUM> can rotate inside the insertion hole <NUM> relative to the insertion hole <NUM> (reinforcing member <NUM>).

Each of the support holes <NUM> has an inner-diameter dimension slightly smaller than the outer-diameter dimension of the tip-end portion of each of the input-side engaging portions <NUM>. The reinforcing member <NUM> spans between the tip-end portions of the pair of input-side engaging portions <NUM> by press-fitting the tip-end portions of the pair of input-side engaging portions <NUM> into the support holes <NUM> of the reinforcing member <NUM>.

In the construction of this example, a pair of engaging elements <NUM> and a pair of elastic members <NUM> are arranged between the input arm portions <NUM> which are parts of the input member <NUM> and the reinforcing member <NUM> in the axial direction. As a result, the positions in the axial direction of the pair of engaging elements <NUM> and the pair of elastic members <NUM> are regulated between the input arm portions <NUM> of the input member <NUM> and the reinforcing member <NUM>.

Specifically, in this state, the side surfaces on the other side in the axial direction of the input arm portions <NUM> are brought into sliding contact with or brought to closely face the side surfaces on the one side in the axial direction of the oscillation-support shafts <NUM> and the side surfaces on the one side in the axial direction of the link members <NUM> on the one side in the axial direction. As a result, the oscillation-support shafts <NUM> are prevented from coming off from the oscillation-support portions <NUM> of the body plates <NUM> to the one side in the axial direction, and the link members <NUM> on the one side in the axial direction are prevented from coming off from the oscillation-support shafts <NUM> to the one side in the axial direction.

Further, the side surface on the one side in the axial direction of the reinforcing member <NUM> is brought into sliding contact with or brought to closely face the side surfaces on the other side in the axial direction of the oscillation-support shafts <NUM> and the side surfaces on the other side in the axial direction of the link members <NUM> on the other side in the axial direction. As a result, the oscillation-support shafts <NUM> are prevented from coming off from the oscillation-support portions <NUM> of the body plates <NUM> to the other side in the axial direction, and the link members <NUM> on the other side in the axial direction are prevented from coming off from the oscillation-support shafts <NUM> to the other side in the axial direction.

However, in a case of implementing the present invention, it is also possible to prevent the link members from coming off from the oscillation-support shafts by retaining rings or the like that are fitted at the end portions in the axial direction of the oscillation-support shafts.

In the construction of this example, the pair of engaging elements <NUM> and the pair of elastic members <NUM> are not strongly held from both sides in the axial direction by the input arm portions <NUM> of the input member <NUM> and the reinforcing member <NUM>. Accordingly, the input arm portions <NUM> of the input member <NUM> and the reinforcing member <NUM> do not interfere the radial movement of the engaging elements <NUM> and the elastic members <NUM> and the oscillation of the link members <NUM>.

In a case of implementing the present invention, as long as the positions in the axial direction of the pair of engaging elements <NUM> and the pair of elastic members <NUM> can be regulated and the radial movement of the engaging elements <NUM> and the elastic members <NUM> and the oscillation of the link members <NUM> are not interfered as described above, both end portions in the axial direction of the input-side engaging pins may be fitted inside the support holes respectively provided on the input arm portions and on the reinforcing member without interference. In this case, the input-side engaging pins may be prevented from coming off by retaining rings fitted at the end portions of the input-side engaging pins, the inner surface of the housing, and the like.

In a case of implementing the present invention, regulating the position in the axial direction of the elastic member <NUM> may also be performed only by the input arm portion <NUM> of the input member <NUM> and the reinforcing member <NUM>. In this case, an engagement construction between the elastic member and the engaging element for regulating the position in the axial direction of the elastic member may be omitted.

Next, the operation of the reverse-input blocking clutch <NUM> of this example will be described.

As illustrated in <FIG>, when a rotational torque is input to the input member <NUM> from the input-side mechanism, the input-side engaging portions <NUM> rotate in the direction of rotation of the input member <NUM> (clockwise direction in the example in <FIG>). When this occurs, while the link members <NUM> is oscillated about the oscillation-support shafts <NUM>, the input-side engaging portions <NUM> pull the oscillation-support shafts <NUM> through the link members <NUM> so that the engaging elements <NUM> (body plates <NUM>) respectively moves to the inner side in the radial direction, which is a direction away from the pressed surface <NUM>. As a result, the elastic members <NUM> are elastically deformed so that the pressing surfaces <NUM> of the engaging elements <NUM> are separated from the pressed surface <NUM> and the elastic pressing portions <NUM> as a whole is deformed toward the outer side in the radial direction. In other words, the elastic members <NUM> are elastically deformed so as to displace the respective support plate portions <NUM> to the inner side in the radial direction. Further, the pair of output-side engaged portions <NUM> of the engaging elements <NUM> hold the output-side engaging portion <NUM> of the output member <NUM> from both sides in the radial direction, and the output-side engaging portion <NUM> and the pair of output-side engaged portions <NUM> engage with no looseness. As a result, the rotational torque input to the input member <NUM> is transmitted to the output member <NUM> through the pair of engaging elements <NUM> and output from the output member <NUM>.

Particularly, in the construction of this example, when the engaging element <NUM> moves to the inner side in the radial direction as described above, as illustrated in <FIG> and <FIG> over time, the guided surfaces <NUM> located on both sides in the width direction of the output-side engaged portion <NUM> are guided by the guide surfaces <NUM> located on both sides in the major axis direction of the front-half portion in the minor axis direction of the output-side engaging portion <NUM>, regulating the movement of the engaging element <NUM> in the width direction. Then, as illustrated in <FIG> and <FIG>, the bottom surface <NUM> of the output-side engaged portion <NUM> comes into surface contact with the side surface <NUM> of the output-side engaging portion <NUM>, and the guided surfaces <NUM> of the output-side engaged portion <NUM> come into surface contact with the guide surfaces <NUM> of the output-side engaging portion <NUM>. Therefore, in the construction of this example, it is possible to effectively prevent the engaging element <NUM> from shifting in the width direction and from coming into contact with the pressed surface <NUM> after releasing the locked or semi-locked state. In the construction of this example, since the output-side engaging portion <NUM> can be used to guide the engaging element <NUM> to the inner side in the radial direction, the number of parts can be reduced compared to a construction in which a separate part used only for the guidance is incorporated.

In the construction of this example, the guided surfaces <NUM> of the output-side engaged portion <NUM> are configured by concave curved surfaces inclined in directions in which the distance between the two guided surfaces <NUM> increase as going toward the inner side in the radial direction, and the guide surfaces <NUM> of the output-side engaging portion <NUM> are configured by convex curved surfaces that match the concave curved surfaces. Therefore, as illustrated in <FIG>, when the engaging element <NUM> is separated from the output-side engaging portion <NUM> to the outer side in the radial direction, a gap is formed between the guided surfaces <NUM> and the guide surfaces <NUM>, and the size (dimension in the width direction) of the gap becomes larger as going toward the outer side in the radial direction. Therefore, in the construction of this example, in a state in which the engaging element <NUM> is separated from the output-side engaging portion <NUM> to the outer side in the radial direction, the movement of the engaging element <NUM> in the width direction and in the direction of rotation can be suitably allowed, and it is possible to effectively prevent excessive force from being applied to the engaging element <NUM>.

On the other hand, when rotational torque is reversely input to the output member <NUM> from the output-side mechanism, as illustrated in <FIG>, the output-side engaging portion <NUM> rotates between the pair of output-side engaged portions <NUM> in the direction of rotation of the output member <NUM> (clockwise direction in the example of <FIG>). Then, corner portions that are the connecting portions between the side surfaces <NUM> and the guide surfaces <NUM> of the output-side engaging portion <NUM> elastically deform the elastic members <NUM> so as to displace a part of the elastic pressing portions <NUM> toward the outer side in the radial direction and directly press the bottom surfaces <NUM> of the output-side engaged portions <NUM>. Due to this, the engaging element <NUM> is moved in a direction (outer side in the radial direction) closer to the pressed surface <NUM> so as to press the pressing surfaces <NUM> of the engaging element <NUM> against the pressed surface <NUM> to be frictionally engaged. As a result, the rotational torque reversely input to the output member <NUM> is completely blocked by being transmitted to the non-rotating housing <NUM> that is fixed to another member, alternatively, only a part of the rotational torque reversely input to the output member <NUM> is transmitted to the input member <NUM> and the remaining part is blocked.

In order to completely block the rotational torque reversely input to the output member <NUM> and prevent it from being transmitted to the input member <NUM>, the engaging element <NUM> is held between the output-side engaging portion <NUM> and the pressed surface <NUM> to lock the output member <NUM> so that the pressing surfaces <NUM> do not slide or rotate relative to the pressed surface <NUM>. On the other hand, in order to transmit only a part of the rotational torque reversely input to the output member <NUM> to the input member <NUM> and block the remaining part, the engaging element <NUM> is held between the output-side engaging portion <NUM> and the pressed surface <NUM> to semi-lock the output member <NUM> so that the pressing surfaces <NUM> slide against the pressed surface <NUM>. When rotational torque is reversely input to the output member <NUM> in a state where the output member <NUM> is semi-locked, the engaging element <NUM> rotates about the rotation center of the output member <NUM> while causing the pressing surfaces <NUM> slide against the pressed surface <NUM> based on the engagement between the output-side engaging portion <NUM> and the output-side engaged portions <NUM>. When the engaging element <NUM> rotates, the input-side engaging portion <NUM> is pulled by the oscillation-support shaft <NUM> through the link members <NUM>, and a part of the rotational torque is transmitted to the input member <NUM>.

In this example, since the engaging element <NUM> has pressing surfaces <NUM> at two locations separated in the circumferential direction of the outer-side surface in the radial direction of the body plate <NUM>, the frictional engagement force between the pressed surface <NUM> and the pressing surfaces <NUM> can be increased by the wedge effect when rotational torque is reversely input to the output member <NUM>. However, in a case of implementing the present invention, it is also possible to employ a construction having a pressing surface only at one location in the circumferential direction of the outer-side surface in the radial direction of the body plate.

In the reverse-input blocking clutch <NUM> of this example, the input-side housing element <NUM> having the pressed surface <NUM> and the output-side housing element <NUM> having the mounting portion <NUM> fixed to the fixed member <NUM> are configured separately. In other words, the input-side housing element <NUM> having the pressed surface <NUM> is not fixed directly to the fixed member <NUM> by bolting. Due to this, by screwing the supporting bolts inserted through the mounting holes <NUM> of the output-side housing element <NUM> into the screw holes <NUM> of the fixed member <NUM> and further tightening them, it is possible to prevent the input-side housing element <NUM> from being deformed with supporting and fixing the housing <NUM> to the fixed member <NUM>. Accordingly, it is possible to prevent deterioration of the roundness of the pressed surface <NUM> provided on the inner peripheral surface of the input-side large-diameter tubular portion <NUM> of the input-side housing element <NUM>. As a result, the locking performance of switching the reverse-input blocking clutch <NUM> from the unlocked state to the locked state or the semi-locked state may be well secured, and/or the controllability of the mechanical device in which the reverse-input blocking clutch <NUM> is incorporated may be well secured.

Further, the input-side in-row fitting surface <NUM> provided on the outer peripheral surface of the input-side large diameter tubular portion <NUM> of the input-side housing element <NUM> and the output-side in-row fitting surface <NUM> provided on the inner peripheral surface of the tubular portion <NUM> of the output-side housing element <NUM> are fitted without looseness. Accordingly, even if the pressed surface <NUM> is pressed toward outside in the radial direction by the pressing surfaces <NUM> of the engaging elements <NUM> as a result of the reverse input of the rotational torque to the output member <NUM>, it is possible to prevent the pressed surface <NUM> from being deformed toward the outside in the radial direction.

As illustrated by double-dotted line in <FIG>, the reverse-input blocking clutch <NUM> of this example may also include a reinforcing rib <NUM> spanning between the outer peripheral surface of the input-side small diameter tubular portion <NUM> of the input-side housing element <NUM> and the side surface on the one side in the axial direction of the side plate portion <NUM>. By providing the reinforcing rib <NUM>, deformation of the pressed surface <NUM> can be prevented more effectively.

With the reverse-input blocking clutch <NUM> according to this example, looseness of the output member <NUM> can be suppressed even in the neutral state.

In other words, in this example, the elastic members <NUM> are arranged at positions overlapping the output-side engaging portion <NUM> with regard to the radial direction of the body plates <NUM> which corresponds to the first direction, and are elastically held between the output-side engaging portion <NUM> and the engaging elements <NUM>. Therefore, even in a case where the distance between the pair of bottom surfaces <NUM> in the assembled state of the reverse-input blocking clutch <NUM> is somewhat larger than the thickness dimension in the minor axis direction of the output-side engaging portion <NUM>, that is the distance between the pair of side surfaces <NUM>, considering the workability of the assembly work of the reverse-input blocking clutch <NUM>, regardless of the gaps existing between the output-side engaging portion <NUM> and the output-side engaged portions <NUM>, the output-side engaging portion <NUM> can be prevented from rotating with a light force, and looseness of the output member <NUM> can be suppressed. As a result, when the reverse-input blocking clutch <NUM> of this example is used for purposes such as adjusting the position of the stage fixed to the nut or adjusting the steering angle of a tire by connecting the output member <NUM> to a screw shaft of the ball screw device and connecting the input member <NUM> to an electric motor or the like, even if rotational torque is reversely input to the output member <NUM> from the stage or the tire through the nut, it is possible to prevent the position of the state and the steering angle of the tire from deviating vigorously from the position after adjustment. In other words, it is possible to moderate the progress of the displacement and prevent the occurrence of abnormal noise.

Although different from the construction of this example, when the engaging element includes two body plates separately arranged in the axial direction of the pressed surface, it is possible to easily avoid interference between the output-side engaged portion and the elastic member provided on the inner-side surfaces in the radial direction of the body plate by locating the elastic member between the two body plates. In other words, the output-side engaging portion of the output member and the output-side engaged portion of the body plates can be easily engaged directly without through the elastic member. On the other hand, as in the construction of this example, when the engaging element includes only one body plate, to avoid interference between the output-side engaged portion and the elastic member by the same method as described above, it is necessary to prepare a groove for installing the elastic member on the inner-side surface in the radial direction of the body plate. As a result, the shape of the body plate becomes complicated, and the difficulty of processing the body plate increases, which inevitably increases the manufacturing cost.

On the other hand, in the construction of this example, the elastic member <NUM> includes an elastic pressing portion <NUM> that is elastically pressed against the output-side engaging portion <NUM> of the output member <NUM>, and the elastic pressing portion <NUM> is arranged separately on both sides in the axial direction with respect to the output-side engaged portion <NUM> of the body plate <NUM>. As a result, interference between the output-side engaged portion <NUM> and the elastic member <NUM> provided on the inner-side surface in the radial direction of the body plate <NUM> can be easily avoided without preparing any groove for installing the elastic member <NUM> on the inner-side surface in the radial direction of the body plate <NUM>. Therefore, since any groove for installing the elastic member <NUM> is not required to be prepared on the inner-side surface in the radial direction of the body plate <NUM>, the shape of the body plate <NUM> can be simplified so that the degree of difficulty in processing the body plate <NUM> can be reduced and the manufacturing cost can be reduced. As long as the elastic member of the present invention does not hinder the engagement between the output-side engaging portion <NUM> and the output-side engaged portion <NUM> and includes the elastic pressing portion <NUM> that elastically presses the output-side engaging portion <NUM> toward the inner side in the radial direction, it can be applied not only to the construction in which the engaging element includes only one body plate, but also to the construction in which the engaging element includes two or more body plates.

In this example, the elastic member <NUM> is not fixed to either the output member <NUM> (output-side engaging portion <NUM>) or the engaging element <NUM>, but is elastically held between the output-side engaging portion <NUM> and the engaging element <NUM>. Due to this, the work for fixing the elastic member <NUM> can be omitted, and the parts used for fixing it can be reduced. As a result, the manufacturing cost of the reverse-input blocking clutch <NUM> can be reduced. Further, since the installation space of the elastic member <NUM> can be reduced, the size of the reverse-input blocking clutch <NUM> can be reduced.

By engaging the elastic member <NUM> with the engaging element <NUM> (body plate <NUM>), displacement of the elastic member <NUM> in the axial direction, the width direction, and the radial direction can be regulated. Therefore, even if the elastic member <NUM> is not fixed to either the output member <NUM> or the engaging element <NUM>, it is possible to prevent the installation position of the elastic member <NUM> from deviating and to prevent the elastic member <NUM> from coming off from between the output-side engaging portion <NUM> and the engaging element <NUM>. Accordingly, the elastic member <NUM> can apply elasticity of a desired magnitude and direction to the engaging element <NUM> and the output-side engaging portion <NUM>.

The elastic member <NUM> has a function to press the pressing surface <NUM> of the engaging element <NUM> against the pressed surface <NUM> in the neutral state. Therefore, in the neutral state, there is no need to provide a dedicated component (biasing member such as a spring) for pressing the pressing surface <NUM> of the engaging element <NUM> against the pressed surface <NUM>. Accordingly, the number of parts can be reduced, and the size of the reverse-input blocking clutch <NUM> can be reduced.

With the reverse-input blocking clutch <NUM> of this example, when rotational torque is input to the input member <NUM>, it is possible to smoothly switch from the locked or semi-locked state to the unlocked state. This point will be described with reference to <FIG>and <FIG>.

<FIG> illustrate mutual positional relationships between a part of the input member <NUM> and a part of an engaging element <NUM> in the construction of this example. More specifically, <FIG> illustrates a positional relationship in the locked or semi-locked state illustrated in <FIG> in which the input-side engaging portion <NUM> is positioned in the central portion in the width direction of the engaging element <NUM> and the link member <NUM> is most radially inward. <FIG> illustrates a positional relationship in a state where translational load F begins to act from the input-side engaging portion <NUM> to the oscillation-support shaft <NUM> through the link member <NUM> as rotational torque T is input to the input member <NUM> and the input-side engaging portion <NUM> rotates in a direction of rotation of the input member <NUM> (clockwise direction in the illustrated example) from the state illustrated in <FIG>.

On the other hand, <FIG> illustrate mutual positional relationships between a part of the input member 109z and a part of the engaging element <NUM> in the construction of a reference example in which a link member is not provided and an engaging element <NUM> that is integrally configured and has an input-side engaged portion <NUM> and an output-side engaged portion (not illustrated). More specifically, <FIG> illustrates a positional relationship in the locked or semi-locked state in which the input-side engaging portion 113z is positioned in the central portion in the width direction of the engaging element <NUM>. <FIG> illustrates a positional relationship in a state where translational load Ft based on rotational torque T begins to act on the contact portion X between the input-side engaging portion 113z and the input-side engaged portion <NUM> from the state illustrated in <FIG>, as the input-side engaging portion 113z rotates in a direction of rotation of the input member 109z (clockwise direction in the illustrated example) and comes into contact with the input-side engaged portion <NUM> of the engaging element <NUM> due to the rotational torque T input to the input member 109z.

In the construction of the reference example, as illustrated in <FIG>, the direction of the translational load Ft, in other words, the direction of the load acting on the engaging element <NUM> from the input member 109z is greatly inclined with respect to the radial direction of the engaging element <NUM> (direction of the engaging element <NUM> moving away from or toward the pressed surface), which is a direction in which the engaging element <NUM> is to be moved when switching from the locked or semi-locked state to the unlocked state.

On the other hand, in the construction of this example, as illustrated in <FIG>, the direction of the translational load F, in other words, the direction of the load acting on the engaging element <NUM> from the input member <NUM> is mostly parallel with the radial direction of the engaging element <NUM> (direction of the engaging element <NUM> moving away from or toward the pressed surface <NUM>), which is a direction in which the engaging element <NUM> is to be moved when switching from the locked or semi-locked state to the unlocked state. In other words, the angle between the direction of the translational load F and the direction in which the engaging element <NUM> is to be moved is smaller than the angle between the direction of the translational load Ft and the direction in which the engaging element <NUM> is to be moved in the construction of the reference example. That is, in the construction of this example, the rotational torque T input to the input member <NUM> can be efficiently converted into a load for moving the engaging element <NUM> to the inner side in the radial direction. Therefore, with the construction of this example, when rotational torque is input to the input member <NUM>, it is possible to smoothly switch from the locked or semi-locked state to the unlocked state.

In the construction of this example, from the view point of simplifying assembly of the reverse-input blocking clutch, the size of the gap G (the difference Wb-Wa as described above) existing between the inner-side surface in the radial direction of the input-side engaging portion <NUM> and the inner peripheral surface of the input-side engaged portion <NUM> of the link member <NUM> in the state illustrated in <FIG> and the size of the gap Gz existing between the inner-side surface in the radial direction of the input-side engaging portion 113z and the input-side engaged portion <NUM> in the state illustrated in <FIG> are preferably as large as possible. On the other hand, from the view point of being able to achieve an unlocked state by immediately moving the engaging element <NUM>, <NUM> to the inner side in the radial direction when rotational torque is input to the input members <NUM> or the input member 109z, the sizes of the gaps G, Gz are preferably as small as possible. Accordingly, taking the circumstances above into consideration, it is necessary in the production of the reverse-input blocking clutch to adjust the size of the gaps G, Gz to an appropriate size.

In the construction of the reference example, in order to adjust the size of the gap Gz, it may be necessary to finish a portion of the input-side engaged portion <NUM> that is in contact with the inner-side surface in the radial direction of the input-side engaging portion 113z with high precision by a cutting process, and in such a case, it is expected that the cost would increase. In the construction of this example, it is possible to adjust the size of the gap G by simply managing the distance between centers of the input-side engaged portion <NUM> and the oscillation-supported portion <NUM> of the link member <NUM>, and since the link member <NUM> can be manufactured by inexpensive press working, it is easy to keep costs down.

Further, when the engaging element is configured by oscillatably supporting the link member having an input-side engaged portion on the body plate having a pressing surface, a construction is conceivable in which a pair of body plates are separately arranged in the axial direction and one link member is oscillatably arranged between the pair of body plates. However, in such a construction, the pair of body plates is required to be connected in a state of being separated in the axial direction, so that the number of parts increases. Further, in the locked or semi-locked state, the body plates are required to have high shape accuracy in order to bring the pressing surfaces of the pair of body plates into contact or sliding contact with the pressed surface.

On the other hand, in this example, a construction is adopted in which a pair of link members <NUM> each having an input-side engaged portion <NUM> on both sides in the axial direction of the body plate <NUM> having a pressing surface <NUM> so as to be oscillatably supported with respect to the body plate <NUM>. Therefore, the number of parts can be suppressed and the shape accuracy of the body plate <NUM> is not required to be excessively increased, an increase in manufacturing cost can be suppressed. Further, when rotational torque is input from the input member <NUM> and the engaging element <NUM> moves to the inner side in the radial direction, the body plate <NUM> can be prevented from inclining in the axial direction.

Since the reinforcing member <NUM> is provided so as to span between the tip-end portions of the pair of input-side engaging portions <NUM>, the pair of input-side engaging portions <NUM> can be prevented from deforming in directions away from each other. The reason for this will be described below.

When rotational torque is reversely input to the output member <NUM>, the pressing surfaces <NUM> of the pair of engaging elements <NUM> are pressed against the pressed surface <NUM>, and the pressing surfaces <NUM> frictionally engage with the pressed surface <NUM> so that the reverse-input blocking clutch <NUM> is switched to the locked or semi-locked state. As the rotational torque reversely input to the output member <NUM> increases, the force pressing the pressing surfaces <NUM> against the pressed surface <NUM> also increases, and the frictional engagement force acting between the pressing surfaces <NUM> and the pressed surface <NUM> also increases.

When rotational torque is input to the input member <NUM>, the pair of input-side engaging portions <NUM> moves the body plates <NUM> through the link members <NUM> and the oscillation-support shafts <NUM> in directions in which the pressing surfaces <NUM> are moved away from the pressed surface <NUM>, and the pressing surfaces <NUM> separate from the pressed surface <NUM>. As a result, the reverse-input blocking clutch <NUM> is switched to the unlocked state.

If the rotational torque that is reversely input to the output member <NUM> is large and the frictional engagement force that acts between the pressing surfaces <NUM> and the pressed surface <NUM> is large when the reverse-input blocking clutch <NUM> switches to the locked or semi-locked state, the torque (release torque) required to switch the reverse-input blocking clutch <NUM> from the locked or semi-locked state to the unlocked state increases. In a construction that does not include the reinforcing member <NUM> as in this example, if the release torque becomes large and the force applied to the input-side engaging portions <NUM> from the link members <NUM> and directed outward with respect to the radial direction of the body plates <NUM> increases when switching the reverse-input blocking clutch <NUM> from the locked or semi-locked state to the unlocked state, the input-side engaging portions <NUM> of the input member <NUM> may possibly be deformed so as to be curved away from each other. When such deformation occurs, uneven contact may occur between the input-side engaging portions <NUM> and the input-side engaged portions <NUM>, and when switching the reverse-input blocking clutch <NUM> from the locked or semi-locked state to the unlocked state, the body plates <NUM> may incline in the axial direction, making it difficult to smoothly switch to the unlocked state.

In the reverse-input blocking clutch <NUM> of this example, since the reinforcing member <NUM> is provided so as to span between the tip-end portions of the pair of input-side engaging portions <NUM>, it is possible to prevent the input-side engaging portions <NUM> from deforming in directions away from each other. As a result, it is possible to prevent uneven contact between the input-side engaging portions <NUM> and the input-side engaged portions <NUM> so as to suppress the occurrence of wear and to prevent the body plates <NUM> from inclining in the axial direction, making it possible to smoothly switch to the unlocked state.

In this example, of the inner peripheral surface of the input-side large diameter tubular portion <NUM>, a hardened layer is formed only on the pressed surface <NUM> and its vicinity by induction hardening, and then polished. Due to this, the dimensional accuracy and roundness of the pressed surface <NUM> are well secured while securing the hardness of the pressed surface <NUM>. Further, the reverse-input blocking clutch <NUM> can be smoothly switched from an unlocked state to a locked state or a semi-locked state.

A second example of an embodiment of the present invention will be described using <FIG>.

In the reverse-input blocking clutch 1a of this example, the construction of the input member 2a and the pair of engaging elements 5a are partially different from that of the first example. In the following description, only parts of the construction of the second example that differ from the first example will be described.

In this example, the input member 2a has an input shaft portion <NUM>, a base plate portion <NUM>, and a pair of input-side engaging portions 6a.

The base plate portion <NUM> has a substantially circular end surface shape when viewed from the axial direction.

The input shaft portion <NUM> protrudes from a central portion of the side surface on the one side in the axial direction of the base plate portion <NUM> toward the one side in the axial direction. The pair of input-side engaging portions 6a protrudes from two locations on the opposite sides in the radial direction of the side surface on the other side in the axial direction of the base plate portion <NUM> toward the other side in the axial direction. In this example, each input-side engaging portion 6a of the pair of input-side engaging portions 6a has a substantially elliptical end surface shape extending in the circumferential direction when viewed from the axial direction. In a case of implementing the present invention, the pair of input-side engaging portions may be configured by components that are made separately from the base plate portion.

Each engaging element 5a of the pair of engaging elements 5a is configured by only one body plate 36a having a pressing surface <NUM> and an output-side engaged portion <NUM>. Regarding the body plate 36a, the shape of the outer-side surface in the radial direction including the pair of pressing surfaces <NUM> and the shape of the inner-side surface in the radial direction including the output-side engaged portion <NUM> are the same as in the first example.

The body plate 36a has an input-side engaged portion 47a. In this example, the input-side engaged portion 47a has a substantially rectangular opening shape extending in the width direction of the body plate 36a when viewed from the axial direction, and is configured by a through hole passing through in the axial direction at an intermediate portion in the radial direction of a central position in the width direction of the body plate 36a. The input-side engaged portion 47a has a size that allows the input-side engaging portion 6a to be loosely inserted. Therefore, in a state where the input-side engaging portion 6a is inserted inside the input-side engaged portion 47a, a gap exists in the width direction and in the radial direction of the body plate 36a respectively between the input-side engaging portion 6a and the inner surface of the input-side engaged portion 47a. Accordingly, the input-side engaging portion 6a can be displaced in a direction of rotation of the input member 2a with respect to the input-side engaged portion 47a, and the body plate 36a provided with the input-side engaged portion 47a can be displaced in the radial direction of the body plate 36a with respect to the input-side engaging portion 6a. In this example, the input-side engaged portion 47a includes a flat surface <NUM> facing outward in the radial direction at an end portion of the inner peripheral surface on the inner side with regard to the radial direction of the body plate 36a.

In the assembled state of the reverse-input blocking clutch 1a, the pair of input-side engaging portions 6a of the input member 2a is inserted in the axial direction into the input-side engaged portions 47a of the pair of engaging elements 5a. In a case of implementing the present invention, as in the case of the first example, a reinforcing member which spans between the tip-end portions of the pair of input-side engaging portions 6a.

When rotational torque is input to the input member 2a from the input-side mechanism, as illustrated in <FIG>, the input-side engaging portion 6a rotates in a direction of rotation of the input member 2a on the inner side of the input-side engaged portion 47a. Then, the inner-side surface in the radial direction of the input-side engaging portion 6a presses the flat surface <NUM> of the input-side engaged portion 47a inward in the radial direction, and the engaging element 5a moves away from the pressed surface <NUM>. As a result, the pressing surface <NUM> of the engaging element 5a is separated from the pressed surface <NUM>. Along with this, the elastic member <NUM> elastically deforms so that the elastic pressing portion <NUM> of the elastic member <NUM> displaces to the outer side in the radial direction. Then, the pair of output-side engaged portions <NUM> of the pair of engaging elements 5a hold the output-side engaging portion <NUM> of the output member <NUM> from both sides in the radial direction so that the output-side engaging portion <NUM> and the pair of output-side engaged portions <NUM> engage with no looseness. As a result, the rotational torque input to the input member 2a is transmitted to the output member <NUM> through the pair of engaging elements 5a, and is output from the output member <NUM>.

On the other hand, when rotational torque is reversely input to the output member <NUM> from the output-side mechanism, by the same operation as in the case of the first example illustrated in <FIG>, the elastic member <NUM> elastically deforms, and the rotational torque that is reversely input to the output member <NUM> is completely blocked by being transmitted to the housing <NUM> and is not transmitted to the input member 2a, or only a part of the rotational torque reversely input to the output member <NUM> is transmitted to the input member 2a and the remaining part is blocked.

In the reverse-input blocking clutch 1a of this example, since each engaging element 5a of the pair of engaging elements 5a is configured only by one body plate 36a and does not have a link member and an oscillation-support shaft, the number of parts can be reduced. The other configuration and operational effects are the same as in the first example.

A third example of an embodiment of the present invention will be described using <FIG>.

In the reverse-input blocking clutch 1b of this example, the housing 4a is configured by coupling an input-side housing element 16a having a mounting portion 64a and an output-side housing element 17a having a pressed surface 24a with coupling bolts <NUM>. That is, in this example, the input-side housing element 16a configures the second pressed member element and the output-side housing element 17a configures the first pressed member element.

The input-side housing element 16a includes a tubular portion 63a having a cylindrical shape, an input-side small diameter tubular portion <NUM> having a cylindrical shape, a side plate portion 21a having a hollow circular plate shape, and a plurality of mounting portions 64a.

The tubular portion 63a has an input-side in-row fitting surface 25a configuring the outer-diameter-side fitting surface around the inner peripheral surface thereof.

The input-side small diameter tubular portion <NUM> is arranged on the one side in the axial direction of the tubular portion 63a so as to be coaxial with the tubular portion 63a.

The side plate portion 21a has a hollow circular plate-shaped end surface shape when viewed from the axial direction. An end portion on the outside in the radial direction of the side plate portion 29a is connected to an end portion on the one side in the axial direction of the tubular portion 63a, and an end portion on the inside in the radial direction of the side plate portion 21a is connected to an end portion on the other side in the axial direction of the input-side small-diameter tubular portion <NUM>. The side plate portion 21a has through holes 23a penetrate in the axial direction at a plurality of locations in the circumferential direction of a portion on the outside in the radial direction.

The mounting portions 64a are provided at a plurality of locations that are evenly spaced in the circumferential direction. Each of the mounting portions 64a has a protruding portion 65a protruding from the outer peripheral surface of the tubular portion 63a toward the outside in the radial direction and a mounting hole 32a that penetrates in the axial direction of the protruding portion 65a.

The output-side housing element 17a has an output-side large-diameter tubular portion <NUM> having a cylindrical shape, an output-side small-diameter tubular portion <NUM> having a cylindrical shape, and a side plate portion <NUM> having a hollow circular plate shape.

The output-side large-diameter tubular portion <NUM> has a pressed surface 24a on the inner peripheral surface in an intermediate portion in the axial direction. The pressed surface 24a is configured by a cylindrical surface centered on the center axis of the output-side housing element <NUM>.

The output-side large-diameter tubular portion <NUM> has an output-side in-row fitting surface 30a, which configures an inner-diameter-side fitting surface, on the outer peripheral surface at an end portion on the one side in the axial direction. The output-side in-row fitting surface 30a is configured by a cylindrical surface centered on the center axis of the output-side housing element 17a, and has an outer-diameter dimension that allows the output-side in-row fitting surface 30a to be fitted to the input-side in-row fitting surface 25a without looseness.

The output-side large-diameter tubular portion <NUM> has screw holes 31a opening at an end surface on the one side in the axial direction at a plurality of locations in the circumferential direction that are aligned with the through holes 23a of the input-side housing element 16a.

The housing 4a is configured by coupling and fixing the input-side housing element 16a and the output-side housing element 17a together by fitting the input-side in-row fitting surface 25a of the input-side housing element 16a with the output-side in-row fitting surface 30a of the output-side housing element 17a without looseness, and screwing the coupling bolts <NUM> that are inserted through the through holes 23a into the screw holes 31a and further tightening them in a state where the end surface on the one side in the axial direction of the output-side large-diameter tubular portion <NUM> of the output-side housing element 17a is in contact with a portion on the outside in the radial direction of the side surface on the other side in the axial direction of the side plate portion 21a of the input-side housing element 16a.

In this example, the input-side housing element 16a is supported by and fixed to the fixed member <NUM> by screwing the supporting bolts inserted through the mounting holes 32a into the screw holes <NUM> prvided in the fixed member <NUM> and further tightening them. As a result, the housing 4a is supported by and fixed to the fixed member <NUM>.

In the reverse-input blocking clutch 1b of this example, the input-side housing element 16a having the mounting portions 64a fixed to the fixed member <NUM> and the output-side housing element 17a having the pressed surface 24a are configured separately. Due to this, it is possible to prevent the output-side housing element 17a from being deformed with supporting and fixing the housing 4a to the fixed member <NUM>. As a result, it is possible to prevent deterioration of the roundness of the pressed surface 24a provided on the inner peripheral surface of the output-side large-diameter tubular portion <NUM> of the output-side housing element 17a.

Further, the input-side in-row fitting surface 25a provided on the inner peripheral surface of the tubular portion 63a of the input-side housing element 16a and the output-side in-row fitting surface 30a provided on the outer peripheral surface of the output-side large-diameter tubular portion <NUM> of the output-side housing element 17a are fitted without looseness. As a result, even if the pressed surface 24a is pressed toward outside in the radial direction by the pressing surfaces <NUM> of the engaging elements 5b as a result of the reverse input of the rotational torque to the output member <NUM>, it is possible to prevent the pressed surface 24a from being deformed toward the outside in the radial direction.

In this example, each of the engaging elements 5b has a pressing surface <NUM>, and includes a pair of body plates 36a that are arranged separately in the axial direction and one link member 37a that is oscillatably supported between the pair of body plate 36a. However, as the engaging element, it is also possible to employ an engaging element having a construction in which a pair of link members is oscillatably supported on both sides in the axial direction of one body pate having a pressing surface, such as the engaging element <NUM> of the first example, or an engaging element that is configured by only one body plate, such as the engaging element 5a of the second example. Other configurations and operational effects are the same as in the first example and the second example.

Claim 1:
A reverse-input blocking clutch (<NUM>, 1a, 1b), comprising:
a pressed member (<NUM>, 4a) including a first pressed member element having a pressed surface (<NUM>, 24a) around an inner peripheral surface thereof and an inner-diameter-side fitting surface on an outer peripheral surface thereof, and a second pressed member element having a mounting portion (<NUM>, 64a) fixed to a portion (<NUM>) that does not rotate during use and an outer-diameter-side fitting surface externally fitted to the inner-diameter-side fitting surface without looseness with regard to a radial direction on an inner peripheral surface thereof,
an input member (<NUM>, 2a) rotatably supported with respect to one of the first pressed member element or the second pressed member element,
an output member (<NUM>) coaxially arranged with the input member and rotatably supported with respect to the other of the first pressed member element or the second pressed member element, and
an engaging element (<NUM>, 5a) configured to transmit rotational torque input to the input member (<NUM>, 2a) to the output member (<NUM>) when the rotational torque is input to the input member (<NUM>, 2a) by moving in a direction away from the pressed surface (<NUM>) based on engagement with the input member (<NUM>, 2a) and engaging with the output member (<NUM>), and to completely block rotational torque reversely input to the output member (<NUM>) or transmit a part of the rotational torque reversely input to the output member (<NUM>) to the input member (<NUM>, 2a) and block a remaining part thereof when the rotational torque is reversely input to the output member (<NUM>) by moving in a direction toward the pressed surface (<NUM>, 24a) based on engagement with the output member (<NUM>) to come into contact with the pressed surface (<NUM>, 24a).