Multi-shaft drive device

A multi-shaft drive device is provided that is capable of obtaining an appropriate backlash in an enmeshed state of an output side bevel gear and an input side bevel gear. An output side bevel gear (35) that is biased in the direction of an input side bevel gear by a coil spring contacts a shaft support bush attached to a wall portion (17) in an enmeshed state with the input side bevel gear. A bias direction stroke end of the output side bevel gear (35) is accordingly restricted. Moreover, the wall portion (17) is provided to a gear holder (15) fixed to a device case (10) that supports the input side bevel gear, thereby enabling the axial direction position of the output side bevel gear (35) to always be positioned at a uniform position to enmesh appropriately with the input side bevel gear.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the U.S. National Phase under 35. U.S.C. §371 of International Application PCT/JP2012/051712, filed Jan. 26, 2012, which claims priority to Japanese Patent Application No. 2011-042118, filed Feb. 28, 2011, and Japanese Patent Application No. 2011-042125, filed Feb. 28, 2011. The disclosures of the above-described applications are hereby incorporated by reference in their entirety. The International Application was published under PCT Article 21(2) in a language other than English.

TECHNICAL FIELD

The present invention relates to a multi-shaft drive device that is preferably applied to for example an electric vehicle seat and that drives plural output shafts with a single motor.

BACKGROUND ART

Many vehicle seats are of a type enabling position adjustment of plural portions so as to suit the build and posture of an occupant, the position adjustment includes, for example, sliding the overall seat in the front-rear direction, moving the height of the seat face up and down, or reclining the seatback (backrest). Such adjustment of the plural movable portions may be performed manually, however more convenient electric seats are provided that use the drive of a motor to perform adjustments.

In order to independently drive respective movable portions, a configuration wherein motors are individually coupled to respective drive shafts that are each coupled to a movable portion may be considered, however this would increase the number of motors. Since it is more efficient for a single motor to drive plural output shafts, proposals have been made wherein the power of a motor is transmitted through clutches to respective output shafts coupled to the plural movable portions, and each of the movable portions is selectively driven by connecting and disconnecting the clutches (see for example Japanese Patent Application Laid-Open (JP-A) No. H6-156123). Such known multi-shaft drive devices include driven side bevel gears respectively provided to plural output shafts so as to be capable of moving in the axial direction. The driven side bevel gears are provided in a biased state capable of enmeshing with drive side bevel gears on a motor shaft. The driven side bevel gears are moved towards and away from the drive side bevel gears by cams that press the driven side bevel gears, thereby switching between power transmission paths (Japanese Utility Model Publication (JP-Y) No. S54-41898).Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. H6-156123Patent Document 2: Japanese Utility Model Publication (JP-Y) No. S54-41898

DISCLOSURE OF INVENTION

Technical Subject

In multi-shaft drive devices such as that disclosed in the above Patent Document 2, when driven side bevel gears (output side bevel gears) enmesh with drive side bevel gears (input side bevel gears), there is a need to perform power transmission at an appropriate enmeshing position in an axial direction with an appropriate amount of backlash.

In consideration of the above circumstances, a subject of the present invention is to provide a multi-shaft drive device capable of obtaining an appropriate backlash in an enmeshed state between an output side bevel gear and an input side bevel gear.

Solution Addressing Subject

A multi-shaft drive device of a first aspect includes: plural input side bevel gears that are supported so as to be rotatable with respect to a case and that rotate in response to transmission of power of a motor; plural output side bevel gears that are provided corresponding to each individual of the plural input side bevel gears, that are supported so as to be rotatable with respect to the case and to be capable of projecting forward or retreating with respect to the input side bevel gears, that are biased in a direction to enmesh with the input side bevel gears, and that are respectively coupled to plural movable mechanisms provided to a vehicle such that rotation force can be individually transmitted to the respective movable mechanisms; a selector that is provided so as to be movable with respect to the case and capable of making sliding contact with the plural output side bevel gears, that enmeshes a selected output side bevel gear out of the plural output side bevel gears with the corresponding input side bevel gear, and that separates the other output side bevel gears from the corresponding input side bevel gears; and a stopper that is provided at the case or at a retention member fixed to the case, that makes contact with the output side bevel gear that is enmeshed with the input side bevel gear and that restricts a stroke end in a bias direction of the output side bevel gear.

In the first aspect, the selector that is provided so as to be movable with respect to the case and capable of making sliding contact with the plural output side bevel gears, enmeshes the selected output side bevel gear out of the plural output side bevel gears with the corresponding input side bevel gear, and separates the other output side bevel gears from the corresponding input side bevel gears. The power of the motor is transmitted through the input side bevel gear to the output side bevel gear that is enmeshed with the input side bevel gear, rotating the output side bevel gear. The movable mechanism coupled to the output side bevel gear is accordingly driven.

Note that, the plural output side bevel gears are biased in the direction to enmesh with the corresponding input side bevel gears, and the selected output side bevel gear that is enmeshed with the input side bevel gear makes contact with the stopper. The stroke end in the bias direction of the output side bevel gear is accordingly restricted. Moreover, the stopper is provided at the case or at the retention member fixed to the case that supports the input side bevel gear. The output side bevel gear can accordingly be positioned at a uniform position in the axial direction thereof so as to enmesh appropriately with the input side bevel gear. An appropriate backlash can accordingly be obtained in the enmeshed state between the output side bevel gear and the input side bevel gear.

A multi-shaft drive device of a second aspect is the first aspect, wherein configuration is made such that the selected output side bevel gear is separated from the selector in an enmeshed state of the selected output side bevel gear with the corresponding input side bevel gear.

In the second aspect, in the enmeshed state of the selected output side bevel gear with the corresponding input side bevel gear, namely in a contact state between the selected output side bevel gear and the stopper, the output side bevel gear is separated from the selector. Accordingly, the output side bevel gear can be prevented from making sliding contact with the selector when the output side bevel gear is rotating, thereby enabling wear to the output side bevel gear or the selector accompanying sliding contact to be prevented. The durability of the output side bevel gear and the selector can accordingly be increased.

A multi-shaft drive device of a third aspect is either the first aspect or the second aspect, wherein configuration is made such that the selected output side bevel gear and the stopper make face-to-face contact in an enmeshed state of the selected output side bevel gear with the corresponding input side bevel gear.

In the third aspect, in the enmeshed state of the selected output side bevel gear and the corresponding input side bevel gear, namely in a contact state between the selected output side bevel gear and the stopper, the output side bevel gear and the stopper make face-to-face contact with each other. Face pressure arising at contact portions between the output side bevel gear and the stopper during rotation of the output side bevel gear can accordingly be managed to an appropriate permissible value or below, thereby enabling the amount of wear to the output side bevel gear and the stopper to be suppressed. Moreover, localized wear and uneven wear of the output side bevel gear and the stopper can be prevented, thereby enabling the durability of the output side bevel gear and the stopper to be increased.

A multi-shaft drive device of a fourth aspect is any one of the first aspect to the third aspect, wherein: the stopper includes a wall portion provided at the case or at the retention member; and a contact portion is provided to a leading end in a bias direction of the output side bevel gear and is supported by the wall portion so as to be rotatable with respect to the wall portion and capable of moving along a thrust direction in a state in which the contact portion penetrates a through hole formed in the wall portion.

In the fourth aspect, the wall portion provided to the case or to the retention member supports the output side bevel gear so as to be rotatable and capable of moving along a thrust direction, and also restricts the stroke end in the bias direction of the output side bevel gear. Namely, the wall portion (stopper) that restricts the stroke end of the output side bevel gear also has a function of providing shaft support to the output side bevel gear, enabling configuration to be simplified in comparison to when a stopper and a shaft support portion are provided separately.

A multi-shaft drive device of a fifth aspect is the fourth aspect, wherein a leading end of the contact portion of the output side bevel gear makes sliding contact with the selector.

In the fifth aspect, the leading end, which penetrates the through hole in the wall portion provided to the case or to the retention member, of the contact portion of the output side bevel gear makes sliding contact with the selector, whereby the output side bevel gear projects forwards or retreating with respect to the input side bevel gear. Namely the output side bevel gear separates from the input side bevel gear when the contact portion is pressed towards the opposite side to the input side bevel gear by the selector, and the output side bevel gear enmeshes with the input side bevel gear under a biasing force on release of the pressing of the contact portion. Configuration of the selector can accordingly be simplified by configuring the selector to simply press or release the pressing of the contact portion.

A multi-shaft drive device of a sixth aspect is either the fourth aspect or the fifth aspect, wherein the wall portion is formed at the retention member.

In the sixth aspect, the wall portion that supports the output side bevel gear and restricts the stroke end in the bias direction of the output side bevel gear is formed at the retention member that is fixed to the case. Configuration of the case can accordingly be simplified. During manufacture of the multi-shaft drive device, the retention member (wall portion) and the output side bevel gears can be assembled to the case separately to each other, thereby enabling an assembly operation to be more flexible.

A multi-shaft drive device of a seventh aspect is the sixth aspect, wherein the wall portion is formed with an open cross-section profile open to an output side bevel gear side, and the wall portion includes a pair of reinforcement portions formed so as to face both sides in a radial direction of the output side bevel gear.

In the seventh aspect, the wall portion formed at the retention portion includes the pair of reinforcement portions formed so as to face the both sides in the radial direction of the output side bevel gear. The pair of reinforcement portions can accordingly suppress deformation when the wall portion is being pressed by the output side bevel gear that is biased towards the direction to enmesh with the input side bevel gear. The output side bevel gear can accordingly be positioned at a uniform position in the axial direction thereof with high precision due to contacting the wall portion. Backlash can accordingly be stabilized with a high degree of precision in the enmeshed state of the output side bevel gear and the input side bevel gear.

A multi-shaft drive device of an eighth aspect is either the fourth aspect or the fifth aspect, wherein the wall portion is formed at the case.

In the eighth aspect, the wall portion that provides shaft support to the output side bevel gear and also restricts the stroke end in the bias direction of the output side bevel gear is provided at the case that supports the output side bevel gear and the input side bevel gear. The output side bevel gear can accordingly be positioned with high precision with respect to the input side bevel gear, enabling backlash to be stabilized with a high degree of precision in the enmeshed state of the output side bevel gear and the input side bevel gear.

A multi-shaft drive device of a ninth aspect is the eighth aspect, wherein: the output side bevel gear is mounted so as to be rotatable together as a unit with an output shaft connected to the movable mechanism and be capable of sliding in the thrust direction with respect to the output shaft; and the case further includes a support portion that rotatably supports the output shaft, and a pair of side wall portions integrally formed to the wall portion and the support portion and formed so as to face both sides in a radial direction of the output side bevel gear.

In the ninth aspect, the output side bevel gear is enclosed by the wall portion, the support portion and the pair of side wall portions that all of them are formed to the case, and the stroke end is restricted by the contact with the wall portion, such that the output side bevel gear always enmeshes appropriately with the input side bevel gear. The wall portion is pressed by the output side bevel gear that is biased in the direction of the input side bevel gear, however stress received due to this pressing is not concentrated in the wall portion and is dispersed around the overall case through the pair of side wall portions and the support portion due to integrating the pair of side wall portions and the support portion, enabling deformation of the wall portion to be suppressed. Due to contacting the wall portion, the output side bevel gear can be positioned at a uniform position in the axial direction with high precision, enabling backlash to be stabilized with a high degree of precision in the enmeshed state of the output side bevel gear and the input side bevel gear.

Advantageous Effects of Invention

The present invention exhibits the advantageous effect of providing a multi-shaft drive device that is capable of obtaining an appropriate backlash in an enmeshed state of the output side bevel gear and the input side bevel gear.

DESCRIPTION OF EMBODIMENTS

First Exemplary Embodiment

Explanation follows regarding a first exemplary embodiment of the present invention with reference toFIG. 1toFIG. 16.

(1) Multi-shaft Drive Device Configuration

FIG. 1is a perspective view illustrating a multi-shaft drive device according to the first exemplary embodiment. The multi-shaft drive device selectively drives plural movable mechanisms of an electric seat in a vehicle, not illustrated in the drawings, with a single motor1. In the present example, there are 3 movable mechanisms, namely a lifter mechanism that adjusts a height of a seat face, a reclining mechanism that adjusts an angle of a seatback (backrest portion), and a slide mechanism that adjusts a front-rear position of the seat. These movable mechanisms are actuated by forward and reverse rotation of drive shafts provided to each mechanism.

A device case (case)10and a cover13that covers the device case10can be seen inFIG. 1.FIG. 2is a plan view illustrating a removed state of the cover13.FIG. 3is a perspective view illustrating the inside of the device and the motor1with the device case10and the cover13removed, andFIG. 4is a plan view corresponding toFIG. 3.

As illustrated inFIG. 2, the device case10includes a clutch unit case portion11and a gearbox case portion12to be molded integrally. The clutch unit case portion11and the gearbox case portion12respectively house a clutch unit2and a gearbox3. The motor1is fixed to a back face of the clutch unit case portion11with a motor shaft1ato which a pinion1bis fixed in a state projecting inside the device case10.

As illustrated inFIGS. 5, the clutch unit2includes: plural input portions20that transmit power of the motor1, provided to each of the mechanisms described above; plural output portions30that are individually provided corresponding to each of the plural input portions20, and that are provided with output shafts31that connect to each of the mechanisms described above through power transmission unit; clutch mechanisms40that are provided for each of the input portions20and the output portions30, and that connect and disconnect the power transmission from the input portions20to each of the output shafts31; a selector (switching portion)50that selectively places the clutch mechanisms40in a connected state; and an operation shaft60that actuates the selector50.

The plural input portions20are disposed to the periphery of the pinion1b. The input portions20are formed in circular plate shapes, and each includes an input gear21configured by a flattened cog that enmeshes with the pinion1band an input side bevel gear22formed on one end face of the input gear21. The input gear21and the bevel gear22are formed coaxially to each other on an input shaft23. The input portions20are rotatably supported on the clutch unit case portion11through the input shafts23that run along a Z direction parallel to the motor shaft1a. Note that configuration may be made such that the input gear21and the input side bevel gear22are indirectly supported on the device case10through another member rather than being directly supported on the device case10.

A plate shaped gear holder (retention member)15can be seen inFIG. 4. As illustrated inFIG. 3, the gear holder15is fixed inside the clutch unit case portion11of the device case10covering each of the input portions20. Together with the clutch unit case portion11, the gear holder15supports the plural input side bevel gears22. Two guide projections16projecting in the Z direction are formed at specific locations of the gear holder15.FIG. 6is a plan view illustrating a state in which the gear holder15has been removed.

FIG. 7illustrates the clutch unit2. As illustrated inFIG. 7, the selector50is a substantially rectangular plate shaped member that is long in the Y direction. The selector50is formed with two guide holes54corresponding to the guide projections16and extending in the Y direction. The respective guide projections16are inserted into the guide holes54. The selector50is supported on the gear holder15so as to be capable of sliding in the Y direction guided by the guide projections16.

Out of the two side faces of the selector50running in the Y direction, the side face on the right hand side inFIG. 7is formed with a first cam face51. A lower side of the side face on the left hand side is formed with a second cam face52, and an upper side of the side face on the left hand side is formed with a rack55with a row of teeth running in the Y direction. The operation shaft60is rotatably supported inside the clutch unit case portion11with the rotation axis oriented in the Z direction. The operation shaft60is formed with a pinion61that enmeshes with the rack55. An operation member such as a dial or a lever, not illustrated in the drawings, is fixed to the operation shaft60at the outside of the cover13. When the operation shaft60is rotated through the operation member, the selector50is moved by the rotating pinion61back and forth along the Y direction through the rack55, according to the rotation direction of the operation shaft60.

The motor1is switched ON/OFF and rotation direction is selected by a switch, not illustrated in the drawings. All of the input portions20rotate when the motor1is actuated. The switch is preferably provided to the above operation member since this enables actuation of the clutch unit2, namely selection of the movable mechanism, to be performed in a single operation together with the switching ON/OFF of the motor1.

As illustrated inFIG. 7, the output portions30are disposed facing the respective cam faces51,52on both X direction sides of the selector50. In the present example, two of the output portions30(a first output portion30A and a second output portion30B) are disposed separated from each other in the Y direction facing the first cam face51, and one of the output portions30(a third output portion30C) is disposed facing the second cam face52. The output portions30include the output shafts31, and each of the output portions30is respectively housed in a housing portion14provided inside the clutch unit case portion11in a state in which the output shaft31thrust directions are parallel to an X-Y plane that is orthogonal to the Z direction, and the output shafts31are inclined at a specific angle with respect to the cam faces51,52.

As illustrated inFIGS. 8, each output portion30is configured by: the output shaft31positioned at a uniform distance from the selector50; an output side bevel gear35on a leading end side (selector50side) of the output shaft31that is capable of rotating together as a unit with the output shaft31, that is capable of projecting forwards or retreating along the output shaft31thrust direction with respect to the selector50, and that is mounted coaxially to the output shaft31; and a coil spring39(biasing member) that biases the output side bevel gear35to project forward in the direction of the selector50. In the first exemplary embodiment, the three output side bevel gears35are individually provided corresponding to the three respective input side bevel gears22. The coil springs39bias each of the output side bevel gears35in a direction to enmesh with the corresponding input side bevel gear22.

The output shafts31are formed with a circular cylinder portion33at a leading end side of a large diameter portion32. A flange32A is formed at a rear end of the large diameter portion32. As illustrated inFIG. 7, in the output shaft31of the third output portion30C, the large diameter portion32is supported rotatably and in a thrust direction immovable state inside a circular cylinder shaped shaft bearing holder portion11cformed in the clutch unit case portion11through a shaft bearing bush34(seeFIG. 4). In the output shaft31of the second output portion30B, the large diameter portion32is supported through the shaft bearing bush34in a rotatable and thrust direction immovable state due to being interposed between semicircular cylinder shaped shaft bearing holder portions respectively formed to the clutch unit case portion11and the cover13that configure a circular cylinder shape in a mounted state of the cover13to the device case10.FIG. 7illustrates a semicircular cylinder shaped shaft bearing holder portion11bformed at a clutch unit case portion11side. The output shaft31of the first output portion30A is rotatably supported inside a worm support portion120, described later, formed at the clutch unit case portion11.

As illustrated inFIGS. 8A and 8B, the output side bevel gear35is configured by: a circular cylinder shaped slide shaft36that is externally mounted to an outer peripheral face of the circular cylinder portion33of the output shaft31such that relative rotation therebetween is not possible, namely such that the slide shaft36can rotate together as a unit with the circular cylinder portion33, that is coaxially spline joined to the circular cylinder portion33so as to be capable of sliding in the thrust direction, and that is also capable of projecting forwards or retreating with respect to the selector50along the output shaft31thrust direction; a gear portion37that is integrally formed to a leading end side of the slide shaft36and that enmeshes with the input side bevel gear22of the input portion20when projecting forwards, and a pin38(contact portion) that projects out from the center of the gear portion37. An outer peripheral side spline portion33aand an inner peripheral side spline portion36athat mutually engage with each other are respectively formed to the outer peripheral face of the circular cylinder portion33of the output shaft31and the inner peripheral face of the slide shaft36of the output side bevel gear35.

In the present exemplary embodiment, the output side bevel gear35and the input side bevel gear22configure the clutch mechanism40according to the present invention.

The coil spring39is housed in a compressed state inside the circular cylinder portion33of the output shaft31and the slide shaft36of the output side bevel gear35. The output side bevel gear35is biased in the selector50direction by the coil spring39, and a leading end of the pin38abuts the cam faces51,52. The leading end face of the pin38is formed with a spherical face shape and makes sliding contact with the abutting cam faces51,52when the selector50is moved in the Y direction.

As illustrated inFIG. 7, the first cam face51of the selector50is formed with recessed portions53(a first recessed portion53A and a second recessed portion53B) corresponding to the first output portion30A and the second output portion30B. The second cam face52is formed with a recessed portion53(a third recessed portion53C) corresponding to the third output portion30C. In the present example, the third recessed portion53refers to an inclined face continuing to a Y direction end portion of the selector50. Configuration is made such that when the selector50is moved in the Y direction, the pin38of any one of the output portions30fits into the corresponding recessed portion53.

The overall output side bevel gear35slides in the direction of the selector50due to the pin38fitting into the recessed portion53. When this occurs, the output side bevel gear35engages and enmeshes with the input side bevel gear22, achieving a connected state of the clutch mechanism40. As illustrated inFIG. 7andFIG. 9, in each of the output portions30, the pin38of the output side bevel gear35penetrates a through hole17ain a wall portion17formed at the gear holder15. The output side bevel gears35are therefore indirectly supported by the device case10through the gear holder15. The wall portions17are formed with cross-section profiles opening towards an output side bevel gear35side as viewed along an axial direction of the input side bevel gear22, and are each integrally provided with a pair of reinforcement portions17bformed on both radial direction sides of the output side bevel gears35(seeFIG. 4andFIG. 9). Shaft bearing bushes18are pushed into and fixed to the through holes17a,and the pins38are supported inside the shaft bearing bushes18so as to be capable of sliding rotation and thrust direction movement. The shaft bearing bushes18configure stoppers together with the wall portions17.

In connected state of the clutch mechanism40, namely in the enmeshed state of the output side bevel gear35and the input side bevel gear22, a leading end face37a(seeFIG. 8A) of the gear portion37of the output side bevel gear35contacts (face-to-face contact in this example) a flange portion18aof the shaft bearing bush18, thereby restricting the stroke end (stroke end in the bias direction of the coil spring39) when the output side bevel gear35is projecting forwards. Moreover, in the clutch mechanism40connected state, the leading end face37aof the output side bevel gear35contacts the flange portion18aof the shaft bearing bush18(seeFIG. 9), thereby performing setting such that the output side bevel gear35is positioned in the axial direction at an appropriate position for enmeshing with the input side bevel gear22. Moreover, in the clutch mechanism40connected state, configuration is made such that the pin38of the output side bevel gear35is separated from the selector50(see the first output portion30A inFIG. 7).

When the motor1is actuated and the input portion20rotates with the clutch mechanism40connected, the rotation is transmitted from the input side bevel gear22to the output side bevel gear35, rotating the output side bevel gear35. The rotation of the slide shaft36is transmitted to the output shaft31, rotating the output shaft31. In a state in which the pin38is abutting the cam face51(52) and not fitted into the recessed portion53, the output side bevel gear35is pushed towards the output shaft31side against the coil spring39by the cam face51(52), resulting in a disconnected state of the clutch mechanism40in which the gear portion37is separated from the input side bevel gear22. In the clutch mechanism40disconnected state, the leading end face37aof the output side bevel gear35is separated from the flange portion18aof the shaft bearing bush18.

The output shafts31of each of the output portions30are connected to the drive shafts of each of the movable mechanisms described above through the power transmission units. In the present exemplary embodiment, flexible torque cables5(seeFIG. 2) serving as the power transmission units are connected to the output shafts31of the second output portion30B and the third output portion30C. The torque cable5on the second output portion30B side is connected to the drive shaft of the reclining mechanism mentioned above, and the torque cable5on the third output portion30C side is connected to the drive shaft of the slide mechanism mentioned above. The torque cables5are inserted into mounting holes32b(seeFIG. 8B) formed in rear end faces of the output shafts31of the second output portion30B and the third output portion30C so as to be capable of rotating together as a unit with the output shafts31. When the output shafts31rotate in the clutch mechanism40connected state, the torque cables5rotate, respectively actuating the reclining mechanism and the slide mechanism.

As illustrated inFIG. 4, a worm gear70and a gear77serving as the power transmission member are connected to the output shaft31of the first output portion30A. The worm gear70and the gear77configure the gearbox3mentioned above.

As illustrated inFIG. 10andFIG. 11, the worm gear70is configured including a worm71(power transmission units) formed coaxially and integrally to the rear end of the output shaft31(referred to below as the output shaft31A) of the first output portion30A, and a worm wheel75that enmeshes with the worm71. Namely as illustrated inFIG. 10, the output shaft31A and the worm71of the first output portion30A are formed on a single circular column shaped transmission shaft140. A flange32ais formed at an intermediate portion of the transmission shaft140. The output shaft31, including the circular cylinder portion33formed with the large diameter portion32and the outer peripheral side spline portion33athat is formed to the outer peripheral face, is formed on one end side of the flange32a,and the worm71is formed on the other end side of the flange32a.

As illustrated inFIG. 12andFIG. 13, the worm71is inserted into and rotatably supported in the circular cylinder shaped worm support portion120formed to the gearbox case portion12.

As illustrated inFIG. 14, a worm insertion hole121with a circular cylinder shaped inner peripheral face is formed inside the worm support portion120. The worm insertion hole121is open at both ends. The circular cylinder shaped shaft bearing bush34is fitted into an opening portion121aon one end side of the worm insertion hole121(the left hand side inFIG. 14: the clutch unit2side) so as to be coaxial to the worm insertion hole121. The shaft bearing bush34contacts a ring shaped stopper step portion122formed on the one end side opening portion121a,preventing the shaft bearing bush34from being pulled out of the opening portion121a.The large diameter portion32of the output shaft31A is supported inside the shaft bearing bush34so as to be capable of sliding rotation. A washer141is mounted interposed between the shaft bearing bush34and the flange32a.The flange32aengages with the stopper step portion122through the washer141and the shaft bearing bush34, thereby restricting the overall transmission shaft140from moving towards the clutch unit2side.

A circular column shaped small diameter portion72of uniform diameter is formed coaxially to the worm71at a worm71side end portion of the transmission shaft140with a step portion73interposed therebetween. The small radius portion72is rotatably supported by a shaft bearing portion130that is mounted to an opening portion (referred to below as the insertion side opening portion)121bon the other end side of the worm support portion120.

The inner diameter of the worm insertion hole121is set with a dimension that forms a uniform gap between the inner diameter of the worm insertion hole121and the worm71. As illustrated inFIG. 15, the shaft bearing portion130is configured by a circular cylinder shaped cap131and a circular cylinder shaped shaft bearing bush136that is fixed to a one end side inner peripheral portion of the cap131. On the one end side, an outer peripheral face of the cap131is formed into a smooth circular cylinder face132that can be inserted into the inner peripheral face of the worm support portion120so as to be capable of sliding movement therewith. On the other end side of the cap131, a male thread portion133of larger diameter than the circular cylinder face132is formed coaxially to the circular cylinder face. A circular cylinder face132side end face of the cap131is formed with a shaft bearing hole134that is coaxial to the circular cylinder face132. The shaft bearing bush136is pushed into and fixed to the shaft bearing hole134. The pushed in state of the shaft bearing bush136is completely inside the shaft bearing hole134. A male thread portion133side end face of the cap131is formed with a hexagonal hole135. An insertion side opening portion121bside end portion of the worm support portion120is formed with a female thread portion123into which the male thread portion133is screwed. The shaft bearing bush34, the circular cylinder face132and the male thread portion133that configure the outer peripheral face of the cap131, the shaft bearing hole134of the cap131, and the shaft bearing bush136are all coaxial to the worm insertion hole120a.

The shaft bearing portion130is mounted to the insertion side opening portion121bof the worm support portion120by sliding the circular cylinder face132of the cap131into the insertion side opening portion121bof the worm support portion120and screwing the male thread portion133into the female thread portion123. The small radius portion72of the worm71is inserted into and supported inside the shaft bearing bush136so as to be capable of sliding rotation. Note that in the present exemplary embodiment, a washer74is inserted over the small radius portion72, and the step portion73of the worm71engages with the cap131through the washer74, thereby restricting the overall transmission shaft140from moving towards the direction opposite to the clutch unit2. An intermediate portion of the worm support portion120is formed with a notch124that exposes a portion of the worm71so as to be capable of engaging with the worm wheel75.

The transmission shaft140is set in the worm support portion120in the following manner. Firstly, the shaft bearing bush34and the washer141are mounted to the large diameter portion32of the output shaft31A, and the coil spring39is loaded inside the circular cylinder portion33of the output shaft31A. Then the transmission shaft140is inserted into the worm insertion hole121from the output shaft31side. The pin38is then inserted into the shaft bearing bush18that is fixed to the through hole17aof the wall portion17of the gear holder15, and the outer peripheral side spline portion33aof the output shaft31A is fitted into the inner peripheral side spline portion36aof the output side bevel gear35that is housed in the housing portion14. Next, after fitting the washer74onto the small radius portion72, the circular cylinder face132of the cap131is inserted into the insertion side opening portion121b,and the small radius portion72is inserted into the shaft bearing bush136whilst screwing the male thread portion133into the female thread portion123.

The transmission shaft140that is rotatably supported by the worm support portion120, and the output side bevel gear35that is mounted on the output shaft31A of the transmission shaft140, are thereby coupled together, configuring a compound gear145in which the output side bevel gear35is on a leading end side, the worm71is on a rear end side, and the output side bevel gear35is spline joined to the worm71.

In the transmission shaft140of the compound gear145, the small radius portion72at the rear end portion of the worm71is supported by the shaft bearing bush136of the shaft bearing portion130, and the large diameter portion32of the output shaft31A at the intermediate portion is supported by the shaft bearing bush34disposed in the one end side opening portion121aof the worm support portion120, such that the transmission shaft140is rotatable whilst being positioned in a radial direction. The amount by which the cap131is screwed into the female thread portion123can be adjusted by rotating the cap131, enabling adjustment of the thrust direction position of the worm71.

In the output side bevel gear35of the compound gear145, the leading end pin38is supported by the shaft bearing bush18of the wall portion17of the gear holder15, and a rear end portion of the slide shaft36is rotatably supported through a shaft bearing bush150illustrated inFIG. 11.

The shaft bearing bush150is retained interposed between a semicircular cylinder shaped shaft holder portion11dformed at the clutch unit case portion11of the device case10and a shaft holder portion13dformed at the cover13, as illustrated inFIG. 16. In the output side bevel gear35, the leading end pin38and the rear end portion of the slide shaft36are accordingly respectively supported by the shaft bearing bush18and the shaft bearing bush150so as to be capable of sliding rotation. The output side bevel gear35R can accordingly be positioned with respect to the radial direction thereof in a state of being supported at both ends thereof.

Namely, in the compound gear145in which the transmission shaft140with the integrated output shaft31A and the worm71is spline joined to the output side bevel gear35, the leading end pin38of the output side bevel gear35, the rear end portion of the worm71, the large diameter portion32at the rear end portion of the output shaft31A, and the slide shaft36of the output side bevel gear35are each respectively supported in a state capable of sliding rotation by the shaft bearing bush18, the shaft bearing bush136, the shaft bearing bush34, and the shaft bearing bush150.

In the present exemplary embodiment, in this supported state the clearance between the outer peripheral side spline portion33aof the output shaft31A and the inner peripheral side spline portion36aof the slide shaft36of the output side bevel gear35is set such that shaft misalignment between the transmission shaft140and the output side bevel gear35can be absorbed. In other words, the clearance between the respective spline portions33a,36ais set comparatively loosely such that the outer peripheral side spline portion33aof the output shaft31A can be fitted into the inner peripheral side spline portion36aof the output side bevel gear35even when the output side bevel gear35that is supported by the shaft bearing bushes18,150is not strictly coaxial to the transmission shaft140supported by the shaft bearing bushes34,136due to low mutual coaxiality between the shaft bearing bushes18,150,34,136.

As illustrated inFIG. 4, the gearbox3is configured by the worm gear70that includes the worm71and the worm wheel75that engages with the worm71, and the gear77. The worm wheel75is rotatably supported by the gearbox case portion12. A small diameter gear76is formed at the center of the worm wheel75. The small diameter gear76engages with the gear77. The gear77is fixed to a drive shaft160of the lifter mechanism mentioned above that is orthogonal to the transmission shaft140. When the output shaft31A of the first output portion30A rotates in the clutch mechanism40connected state, the gearbox3is actuated, whereby the worm71is rotated. This rotation is transmitted to the worm wheel75, and the rotation of the worm wheel75is transmitted from the small diameter gear76to the gear77. The drive shaft160of the lifter mechanism is thereby rotated, actuating the lifter mechanism.

In the multi-shaft drive device of the first exemplary embodiment described above, the multi-shaft drive device is fixed to a member such as a seat frame using plural screw insertion holes19provided to peripheral edges of the device case10and the cover13.

(2) Multi-shaft Drive Device Operation

The multi-shaft drive device described above operates as follows.

FIG. 7illustrates a state in which the pin38of the output side bevel gear35of the first output portion30A has been fitted into the first recessed portion53A by rotating the operation shaft60to move the selector50in the Y direction. In this state, the output side bevel gear35of the first output portion30A engages with the input side bevel gear22corresponding to the first output portion30A, resulting in a connected state of the clutch mechanism40. In the other output portions30(the second output portion30B and the third output portion30C), the pins38are pressed by the cam faces51,52and the output side bevel gears35are separated from the corresponding input side bevel gears22, such that the respective clutch mechanisms40are in a disconnected state.

From this state, when the selector50is moved a specific distance in the Y1direction, the pin38of the second output portion30B fits into the second recessed portion53B, and the output side bevel gear35of the second output portion30B enmeshes with the corresponding input side bevel gear22, resulting in a connected state of the clutch mechanism40. When this occurs, in the other output portions30(the first output portion30A and the third output portion30C), the pins38are pressed by the cam faces51,52, and the output side bevel gears35separate from the corresponding input side bevel gears22, such that the respective clutch mechanisms40are in a disconnected state.

When the selector50is again moved a specific distance in the Y1direction, the pin38of the third output portion30C projects forward into the third recessed portion53C, and the output side bevel gear35of the third output portion30C enmeshes with the corresponding input side bevel gear22, resulting in a clutch mechanism40connected state. When this occurs, in the other output portions30(the first output portion30A and the second output portion30B), the pins38are pressed by the cam face51, and the output side bevel gears35separate from the corresponding input side bevel gears22, such that the respective clutch mechanisms40are in a disconnected state.

The selector50is moved back and forth in the Y direction by forward and reverse rotation of the operation shaft60. Along the path of this movement, the pins38project forwards into any one of the recessed portions53A to53C of the selector50, such that when this occurs, one of the output portions30out of the first to third output portions30A to30C is selected as described above. The output side bevel gear35of the selected output portion30enmeshes with the corresponding input side bevel gear22to achieve the clutch mechanism40connected state.

In this connected state of the clutch mechanism40, when the switch is switched ON and the motor1is actuated, the power of the motor1is transmitted from the input side bevel gear22to the output side bevel gear35, rotating the output shaft31. In the second output portion30B and the third output portion30C, the rotation of the output shaft31is transmitted to the drive shafts of the reclining mechanism and the slide mechanism through the torque cables5, actuating the reclining mechanism and the slide mechanism. In the first output portion30A, the rotation of the output shaft31A is transmitted to rotate the drive shaft160of the lifter mechanism through the gearbox3, namely through the worm71, the worm wheel75, the small diameter gear76and the gear77, actuating the lifter mechanism. The rotation direction of the output shafts31and the drive shafts of the movable mechanisms can be switched by switching the rotation direction of the motor1using the switch.

(3) Advantageous Effects of the First Exemplary Embodiment

In the first exemplary embodiment described above, the plural output side bevel gears35are biased in the enmeshing direction with the corresponding input side bevel gears22. The output side bevel gears35that enmesh with the input side bevel gears22contact the shaft bearing bushes18attached to the wall portions17. The bias direction stroke ends of the output side bevel gears are accordingly restricted. Moreover, the wall portions17are provided at the gear holder15that is fixed to the device case10that supports the input side bevel gears22. The axial direction positions of the output side bevel gears35can accordingly always be positioned at uniform positions to enmesh appropriately with the input side bevel gears22. An appropriate backlash can accordingly be obtained in the enmeshed state of the output side bevel gears35with the input side bevel gears22. As a result, tooth end bearing of the gears can be suppressed, increasing durability, and enabling operating noise occurring during enmeshing to be reduced.

Moreover, in the enmeshed state of the output side bevel gears35with the corresponding input side bevel gears22, namely a contact state between the output side bevel gears35and the shaft bearing bushes18, the output side bevel gears35are separated from the selector50. Accordingly, during rotation of the output side bevel gears35, the output side bevel gears35can be prevented from making sliding contact with the selector50, thereby enabling wear of the output side bevel gears35and the selector50accompanying such sliding contact to be prevented. The durability of the output side bevel gears35and the selector50can accordingly be increased.

In the enmeshed state of the output side bevel gears35with the corresponding input side bevel gears22, the output side bevel gears35make face-to-face contact with the flange portions18aof the shaft bearing bushes18. During rotation of the output side bevel gears35, a pressure arising at contact portions of surfaces of the output side bevel gears35and the shaft bearing bushes18can be managed to an appropriate permissible value or below. Wear of the output side bevel gears35and the shaft bearing bushes18can accordingly be suppressed. Since localized wear or uneven wear of the output side bevel gears35and the shaft bearing bushes18can be prevented, the durability of the output side bevel gears35and the shaft bearing bushes18can be increased.

Moreover, in the present exemplary embodiment, the wall portions17provided at the gear holder15support the pins38of the output side bevel gears35so as to be capable of both rotation and movement in the thrust direction, and define the bias direction stroke ends of the output side bevel gears35. Namely, the wall portions17(stoppers) that restrict the stroke ends of the output side bevel gears35are also provided with a function of providing shaft support to the output side bevel gears35, enabling configuration to be simplified in comparison to when stoppers and shaft support portions are provided separately to each other.

Moreover in the present exemplary embodiment, the leading ends of the pins38of the output side bevel gears35penetrate the through holes17aof the wall portions17provided to the gear holder15and make sliding contact with the selector50, thereby projecting forwards or retreating the output side bevel gears35with respect to the input side bevel gears22. Namely, the pins38are pressed towards the opposite side to the input side bevel gears22by the selector50, separating the output side bevel gears35from the input side bevel gears22. On release of this pressing of the pins38, the output side bevel gears35enmesh with the input side bevel gears22due to the biasing force of the coil springs39. The configuration of the selector50can accordingly be simplified, as the selector50is configured so as to simply press or release pressing of the pins38.

In the present exemplary embodiment, the wall portions17that provide shaft support to the output side bevel gears35and restrict the bias direction stroke ends of the output side bevel gears35are formed to the gear holder15that is fixed to the device case10. The configuration of the device case10can accordingly be simplified. During manufacture of the multi-shaft drive device, the gear holder15(wall portions17) and the output side bevel gears35can be assembled to the device case10separately to each other, enabling assembly operations to be more flexible.

Moreover, in the present exemplary embodiment, the wall portion17formed to the gear holder15includes the pairs of reinforcement portions17bthat are formed to face both radial direction sides of the output side bevel gears35. The reinforcement portions17bcan accordingly suppress deformation of the wall portions17when the wall portions17are being pressed by the output side bevel gears35that are biased towards the enmeshing direction with the input side bevel gears22. Due to contacting the wall portions17, positions of the output side bevel gears35in the axial direction can accordingly be designated at uniform positions with high precision. The backlash in the enmeshed state between the output side bevel gears35and the input side bevel gears22can accordingly be stabilized with a high degree of precision.

Supplementary Explanation of the First Exemplary Embodiment

In the first exemplary embodiment described above, the wall portions17are formed with open cross-section profile, however the present invention is not limited thereto, and the configuration of the wall portion may be modified as appropriate. There is no limitation of the stopper according to claim1to a wall shape, and the shape thereof may be modified as appropriate.

In the first exemplary embodiment described above, it is the leading ends of the pins38of the output side bevel gears35that make sliding contact with the selector50, however the present invention is not limited thereto, and portions of the output side bevel gears that make sliding contact with the selector may be varied as appropriate.

Moreover, in the first exemplary embodiment described above, configuration is made wherein the wall portions17(stoppers) that restrict the biasing direction stroke ends of the output side bevel gears35also provide shaft support to the output side bevel gears35, however the present invention is not limited thereto. Configuration may be made wherein stoppers and shaft support portions are provided separately to each other.

Moreover, in the first exemplary embodiment described above, the output side bevel gears35and the shaft bearing bushes18of the wall portions17make face-to-face contact with each other, however the present invention is not limited thereto and appropriate modifications may be made to the manner in which the output side bevel gears and the stoppers contact each other. However, a configuration that enables the durability of the output side bevel gears and the stoppers to be secured is preferable.

In the first exemplary embodiment described above, configuration is made wherein the output side bevel gears35are separated from the selector50in the enmeshed state of the output side bevel gears35and the input side bevel gears22(the clutch connected state), however the present invention is not limited thereto, and configuration may be made wherein the output side bevel gears and the selector are constantly in contact with each other. The above supplementary explanation similarly applies to the second exemplary embodiment of which explanation follows.

In the first exemplary embodiment described above, configuration is made wherein the gear holder15that is fixed to the device case10serves as a retention member, however the present invention is not limited thereto, and the retention member may be any member that is fixed to the case.

Moreover, in the first exemplary embodiment described above, configuration is made wherein the coil springs39serving as biasing members are provided inside the output side bevel gears35and the output shafts31, however the present invention is not limited thereto, and configuration may be made wherein the biasing members are provided to the outside of the output side bevel gears and the output shafts.

Second Exemplary Embodiment

Explanation follows regarding a multi-shaft drive device according to a second exemplary embodiment of the present invention, with reference toFIG. 17toFIG. 21.

(1) Multi-shaft Drive Device Configuration

FIG. 17andFIG. 18are respectively a perspective view and a plan view of a multi-shaft drive device according to the second exemplary embodiment. As can be seen inFIG. 17andFIG. 18, a case201includes a recessed area202that is open upwards, a selector210is housed inside the recessed area202of the case201, and a motor220is fixed to a lower portion of the case201. The opening of the recessed area202of the case201is covered by a cover, not illustrated in the drawings, that is fixed to the case201. The selector210is a substantially rectangular plate shaped member that is long in the Y direction inFIG. 18, and is formed with 2 guide holes219extending in the Y direction at a width direction (X direction) central portion. Guide projections203projecting from a bottom portion of the recessed area202are respectively inserted into the guide holes219, with the guide holes219being guided by the guide projections203such that the selector210is supported so as to be capable of sliding in the Y direction.

Out of the two length direction side faces of the selector210, a first cam face211is formed on the side face on the right hand side inFIG. 18. A second cam face212is formed on a lower side of the side face on the left hand side, of which an upper side is formed with a rack218with a row of teeth running along the Y direction. A pinion217that is rotatably supported to the case201enmeshes with the rack218. A dial, not illustrated in the drawings, that is disposed above the cover is fixed to the pinion217through a rotation shaft. The pinion217rotates when the dial is rotated, and the selector210is moved back and forth along the Y direction through the rack218according to the rotation direction of the dial.

As illustrated inFIG. 19andFIG. 20, output portions230are disposed on both X direction sides of the selector210facing the respective cam faces211,212. In the present example, two of the output portions230(a first output portion230A and a second output portion230B) are disposed facing the first cam face211separated from each other in the Y direction, and one of the output portions230(a third output portion230C) is disposed facing the second cam face212. The output portions230are housed in housing portions260formed at the case201as illustrated inFIG. 17andFIG. 18.

As illustrated inFIG. 18andFIG. 20, a motor shaft221of the motor220projects upwards. The motor shaft221can be rotated forwards and in reverse. A pinion222is fixed to the motor shaft221. Three input side clutch members250corresponding to the respective output portions230are provided to the periphery of the pinion222and are rotatably supported on the case201. Each of the input side clutch members250is of a similar configuration, and includes an input gear251that enmeshes with the pinion222configured by a flattened cog, and an input side bevel gear252integrally formed to an upper face of the input gear251. The input side clutch members250having the input side bevel gears252are rotatably supported on the case201, thereby positioning the input side clutch members250at specific positions. The motor220is switched ON/OFF, and the rotation direction selected, for example by a switch provided to the dial. When the motor220is actuated, all of the input side clutch members250rotate.

Each of the output portions230(230A to230C) are of similar configuration. As illustrated inFIG. 20andFIG. 21, each of the output portions230is configured including an output shaft231disposed in a state facing the cam face211(212), an output side clutch member232provided so as to be capable of rotating together as a unit with the output shaft231, and also capable of projecting forwards or retreating along the output shaft231axial direction with respect to the cam face211(212), and a coil spring236(biasing member) that biases the output side clutch member232so as to project forward toward the input side bevel gear252.

The output shafts231are rotatably supported by support portions261configuring the housing portions260of the case201. The output shafts231are respectively connected through torque cables, not illustrated in the drawings, to movable mechanisms provided to an electric seat in a vehicle, for example, a mechanism for adjusting the height of a seat face, a reclining mechanism for adjusting the angle of the seatback (backrest portion), and a mechanism for adjusting the front-rear position of the seat. One end portions of the torque cables are inserted into mounting holes231b(seeFIG. 17) of rectangular cross-section profile that are formed to rear end faces of the output shafts231, and rotate together with the output shafts231.

As illustrated inFIGS. 21, the output side clutch members232are each configured including: a circular cylinder shaped slide shaft233that is externally mounted at the selector210side of the output shaft231; an output side bevel gear234with a toothed face integrally formed to a leading end side of the slide shaft233facing towards the selector210side; a pin (contact portion)235that projects out in the axial direction from a central portion of the output side bevel gear234; and a coil spring236that biases the slide shaft233in the direction of the selector210.

An inner peripheral face of the slide shaft233is not capable of relative rotation in a circumferential direction with respect to an outer peripheral face of the output shaft231, namely the slide shaft233is capable of rotating as a unit together with the output shaft231, and the two are spline joined together so as to allow sliding along the axial direction. The slide shafts233are accordingly capable of projecting forwards or retreating in an axial direction of the output shaft231with respect to the cam faces. The coil spring236is housed inside the output shaft231and the slide shaft233in a compressed state, and biases the slide shaft233from the output shaft231towards the cam faces211(212). Leading ends of the pins235of the output side clutch members232accordingly abut the cam faces211(212) when the pins235face the cam faces211(212). Leading end faces of the pins235are formed with spherical face shapes, and make sliding contact with the abutting cam faces211(212) when the selector210is moved in the Y direction by the dial described above.

The first cam face211of the selector210is formed with a first recessed portion213A and a second recessed portion213B serving as cam portions corresponding to the first output portion230A and the second output portion230B, and the second cam face212is formed with a third recessed portion213C serving as a cam portion corresponding to the third output portion230C. When the selector210is operated so as to move along the Y direction as described above, the pin235of any one of the output portions230faces the corresponding recessed portion213A (213B,213C). The output side clutch member232is biased as a whole towards the cam face211(212) by the coil spring236, such that the pin235projects out and fits into the recessed portion213A (213B,213C).

The output side clutch member232slides as a whole in the selector210direction (the direction for engaging with the input side bevel gear252) when the pin235projects out and fits into the recessed portion213A (213B,213C), and the output side bevel gear234enmeshes with the input side bevel gear252, achieving a clutch connected state. When the motor220is actuated and the input side clutch member250rotates within the clutch connected state, the rotation is transmitted from the input side bevel gear252to the enmeshed output side bevel gear234, and the overall output side clutch member232rotates. The rotation of the slide shaft233is transmitted to the output shaft231and the output shaft231rotates, thereby rotating and actuating the torque cable. When the pin235is not in a state facing the recessed portion213A (213B,213C), the pin235contacts the cam face211(212) at a portion other than the recessed portion213A (213B,213C), the cam face211(212) pressing the pin235towards the output shaft231side against the coil spring236. When this occurs, the output side bevel gear234separates from the input side bevel gear252to achieve a clutch disconnected state.

The housing portions260of the case201in which the output portions230are housed are each formed so as to enclose the respective output side clutch member232and include: the circular cylinder shaped support portion261that is positioned at a rear portion side of the output portion230and that rotatably supports the output shaft231in a state restricting movement towards the rear and away from the selector210; a leading end wall portion262(wall portion) positioned at the output portion230leading end side; and a pair of side wall portions263that are integrally formed with the support portion261and the leading end wall portion262so as to couple together the support portion261and the leading end wall portion262, and formed so as to face both sides of the output side clutch member232including the output side bevel gear234. The support portion261, the leading end wall portion262and the pair of side wall portions263are integrally formed to the case201.

The leading end wall portion262is formed with a through hole262awhere the pin235rotatably penetrate. The output side bevel gears234are thereby directly supported by the case201. Each of the output portions230is inserted inside the corresponding housing portion260from an opening upper portion with the coil spring236compressed to a contracted state such that the output side clutch member232and the output shaft231mutually approach each other, with the pin235passed through the through hole262aof the leading end wall portion262. Next, the compressed force is released, and the output shaft231is inserted inside the support portion261, thereby assembling the output portion230inside the housing portion260.

The output shaft231of the output portion230that has been thus assembled inside the housing portion260is rotatably supported by the support portion261. The pin235penetrates the through hole262asuch that both end portions of the output portion230are rotatably supported. When the output side clutch member232that is biased in the selector210direction by the coil spring236is in the clutch connected state wherein the pin235is fitted into any one of the recessed portions213A to213C of the selector210and projecting forwards in the selector210direction, a leading end face234aof the output side bevel gear234contacts (makes face-to-face contact with) an inner face of the leading end wall portion262. Stroke end in the bias direction of the output side bevel gear234is accordingly designated, and the output side bevel gear234is restricted from projecting forward any further toward the selector210side.

In the clutch connected state in which the output side bevel gear234is enmeshed with the input side bevel gear252, setting is made to position the output side bevel gear234in the axial direction at an appropriate enmeshing position with the input side bevel gear252due to the leading end face234aof the output side bevel gear234contacting the inner face of the leading end wall portion262. Moreover, in the clutch disconnected state in which the pin235is pressed by the cam faces211,212of the selector210and the output side bevel gear234has separated from the input side bevel gear252, the leading end face234aof the output side bevel gear234separates from the inner face of the leading end wall portion262.

(2) Multi-shaft Drive Device Operation

Explanation follows regarding operation of the multi-shaft drive device described above.FIG. 18andFIG. 20illustrate a state in which the dial has been rotated, moving the selector210in the Y direction, and the pin235of the output side clutch member232of the first output portion230A is projecting out and fitting into the first recessed portion213A. Here, the output side bevel gear234of the first output portion230A is enmeshed with the input side bevel gear252corresponding to the first output portion230A, achieving the clutch connected state. In the other output portions230(the second output portion230B and the third output portion230C), the pins235are pressed by the cam faces211,212and the output side bevel gears234are separated from the corresponding input side bevel gears252.

When the selector210is moved from this state a specific distance in the Y1 direction, the pin235of the second output portion230B projects out and fits into the second recessed portion213B, and the output side bevel gear234of the second output portion230B enmeshes with the corresponding input side bevel gear252, to achieve a clutch connected state. When this occurs, in the other output portions230(the first output portion230A and the third output portion230C), the pins235are pressed by the cam faces211,212, and the output side bevel gears234separate from the corresponding input side bevel gears252to achieve a clutch disconnected state.

When the selector210is again moved a specific distance in the Y1 direction, the pin235of the third output portion230C projects out and fits into the third recessed portion213C, and the output side bevel gear234of the third output portion230C enmeshes with the corresponding input side bevel gear252, to achieve a clutch connected state. When this occurs, in the other output portions230(the first output portion230A and the second output portion230B), the pins235are pressed by the cam face211, and the output side bevel gears234separate from the corresponding input side bevel gears252to achieve a clutch disconnected state.

The selector210moves back and forth in the Y direction with forward and reverse rotation of the dial. Along the path of this movement, the pins235project out and fit into any one of the recessed portions213A to213C of the selector210, and when this occurs, one of the output portions230out of the first to third output portions230A to230C is selected as described above. The output side bevel gear234of the selected output portion230enmeshes with the corresponding input side bevel gear252to achieve the clutch connected state.

In this clutch connected state, when the switch is switched ON and the motor220is actuated, the power of the motor220is transmitted from the input side bevel gear252to the output side bevel gear234, rotating the overall output side clutch member232, and thereby rotating the output shaft231. The torque cable connected to the output shaft231of the selected output portion230accordingly rotates, achieving an actuated state. The rotation direction of the output shafts231and the torque cables can be switched by switching the rotation direction of the motor220using the switch.

According to the second exemplary embodiment, the respective output portions230are housed in the housing portions260formed at the case201. In this housed state, when in the clutch connected state, the leading end wall portions262are contacted by the leading end faces234aof the output side bevel gears234of the output side clutch members232that are biased in the direction of the input side bevel gears252by the coil springs236. The stroke ends in the bias direction of the output side bevel gears234are accordingly restricted. Moreover, the leading end wall portions262are integrally formed to the case201that supports the input side bevel gears252, thereby enabling the output side bevel gears234to always be positioned at uniform locations in the axial direction thereof so as to enmesh appropriately with the input side bevel gears252. An appropriate backlash can accordingly be obtained in the enmeshed state between the output side bevel gears234and the input side bevel gears252.

The leading end wall portions262are pressed by the output side bevel gears234biased by the coil springs236, however since the leading end wall portions262are integrally formed to the case201together with the support portions261and the pairs of side wall portions263, stress received due to this pushing is not concentrated on the leading end wall portions262and is dispersed around the overall case201through the support portions261and the pairs of side wall portions263, thereby enabling deformation of the leading end wall portions262to be suppressed. The axial direction positions of the output side bevel gears234can accordingly be reliably positioned at uniform positions due to contacting the leading end wall portions262. Moreover, in the present exemplary embodiment, the input side bevel gears252are also supported and positioned by the case201as well as the output side bevel gears234, such that relative positional displacement between the two does not readily occur. Backlash can therefore always be stabilized with a high degree of precision in the enmeshed state of the output side bevel gears234with the input side bevel gears252. The advantageous effects that tooth end bearing of the output side bevel gears234with respect to the input side bevel gears252can be suppressed, increasing durability, and enabling as a result a reduction in operation noise occurring during enmeshing to be obtained.

In the present exemplary embodiment, the output side bevel gears234make face-to-face contact with the leading end wall portions262in the enmeshed state of the output side bevel gears234with the input side bevel gears252. Similarly to in the first exemplary embodiment, a pressure arising at face contact portions between the output side bevel gears234and the leading end wall portions262can accordingly be managed to an appropriate permissible value or below, and wear can be suppressed for both the output side bevel gears234and the leading end wall portions262. Localized wear and uneven wear of the output side bevel gears234and the leading end wall portions262can also be prevented, enabling the durability of both the output side bevel gears234and the leading end wall portions262to be increased.

In the present exemplary embodiment, the leading end wall portions262that restrict the bias direction stroke ends of the output side bevel gears234also have the function of providing shaft support to the output side bevel gears234, thereby enabling configuration to be simplified similarly to in the first exemplary embodiment.

Moreover, in the present exemplary embodiment, in the output side bevel gears234the leading ends of the pins235penetrate the through holes262ain the leading end wall portions262and make sliding contact with the selector210, enabling the configuration of the selector210to be simplified, similarly to in the first exemplary embodiment.

Note that in the second exemplary embodiment, the selector210of the present invention is configured so as to move along a straight line, however modification may be made to the present invention such that the selector210is a circular plate shaped rotating member with the peripheral face configuring the cam face, wherein the plural output portions230are disposed to the periphery of the cam face. Such a configuration of the selector similarly applies to the first exemplary embodiment.