Clutch for vehicle

A clutch for a vehicle includes a hub disposed on a rotary shaft such that a rotation thereof is restricted, a sleeve spline-coupled to an outer circumference of the hub, a clutch member disposed on the rotary shaft, and a clutch ring disposed between the clutch member and the hub, wherein the clutch ring is pressed against the clutch member by the sleeve and the hub, wherein the clutch ring comprises a pressed part to which an amount of force pressing against the clutch member is applied from the sleeve and the hub, the sleeve comprises pressing protrusions that transfer the axial driving force of the sleeve to the pressed part, and the hub comprises displacement converting portions that convert a relative rotational displacement with respect to the clutch ring into an axial linear displacement of the clutch ring.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims the benefit of priority to Korean Patent Application Number 10-2015-0154443, filed on Nov. 4, 2015 with the Korean Intellectual Property Office, the entire contents of which application are incorporated herein for all purposes by this reference.

TECHNICAL FIELD

The present disclosure generally relates to a clutch for a vehicle. More particularly, the present disclosure relates to a clutch for a vehicle being able to be used in a transmission of a vehicle.

BACKGROUND

A plurality of clutches is used in a transmission of a vehicle to control the transmission of power between rotary bodies that rotate relative to each other.

It is preferable that such a clutch has as small a volume as possible and a torque transmission capacity as large as possible. However, the volume of the clutch must generally be increased in order to obtain a larger torque transmission capacity.

In addition, in order to transmit a large amount of torque, the amount of force actuating the clutch must be increased. Thus, an apparatus for actuating the clutch, such as an actuator, is required to have a relatively larger size.

SUMMARY OF THE DISCLOSURE

Accordingly, the present disclosure has been made keeping in mind the above problems occurring in the related art, and the present disclosure is intended to propose a clutch for a vehicle, the clutch being able to realize a relatively large torque transmission capacity while having a simple and compact configuration and a relatively small volume. The clutch can reduce the size and power of an actuator by reducing the amount of driving force of the clutch required to transmit torque. The clutch can transmit a relatively large amount of torque while the size of a clutch system is reduced as small as possible.

In order to achieve the above object, according to one aspect of the present disclosure, a clutch for a vehicle may include: a hub disposed on a rotary shaft such that a rotation thereof is restricted; a sleeve spline-coupled to the outer circumference of the hub such that the sleeve is able to linearly slide in a longitudinal direction of the rotary shaft; a clutch member disposed on the rotary shaft such that the clutch member and the rotary shaft are rotatable relative to each other; and a clutch ring disposed between the clutch member and the hub, wherein the clutch ring is pressed against the clutch member by the sleeve and the hub such that the clutch ring transmits torque using frictional force formed between the clutch ring and the clutch member. The clutch ring includes a pressed part to which an amount of force pressing against the clutch member is applied from the sleeve and the hub. The sleeve includes pressing protrusions that transfer the axial driving force of the sleeve to the pressed part. The hub includes displacement converting portions converting a relative rotational displacement with respect to the clutch ring into an axial linear displacement of the clutch ring.

The pressed part of the clutch ring may include pressed protrusions protruding radially outward from outer circumferential surfaces of the clutch ring. The pressing protrusions of the sleeve may protrude radially inward from inner circumferential surfaces of the sleeve. The hub may include accommodation recesses in which the pressed protrusions and the pressing protrusions are accommodated, the displacement converting portions being included in the accommodation recesses.

Each of the accommodation recesses of the hub may include a first recess into which a corresponding pressing protrusion among the pressing protrusions is fitted and a second recess into which a corresponding pressed protrusion among the pressed protrusions is fitted, the first recess and the second recess being connected by a corresponding displacement converting portion among the displacement converting portions.

The width of the second recess in the radial direction of the hub may be greater than the width of the first recess in the radial direction of the hub. The displacement converting portion may include inclined surfaces, the width of which gradually increasing from the first recess toward the second recess.

Each of the pressed protrusions of the clutch ring may have chamfered portions parallel to the inclined surfaces of the displacement converting portion. The radial width of the second width may be greater than the radial width of the pressed protrusion.

The chamfered portions of the pressed protrusion may remain in surface contact with the inclined surfaces of the displacement converting portion even in the case in which the clutch ring is in closest contact with the clutch member.

A plurality of the pressed protrusions, a plurality of the pressing protrusions, and a plurality of the accommodation recesses may be symmetrically arranged in the radial direction of the hub.

The clutch ring may include a clutch surface, and the clutch member may include a clutch surface. The clutch surface of the clutch ring and the clutch surface of the clutch member overlap each other, thereby generating the frictional force.

According to the present disclosure, the clutch for a vehicle can realize a relatively large torque transmission capacity while having a simple and compact configuration and a relatively small volume. The clutch can reduce the size and power of an actuator by reducing the amount of driving force of the clutch required to transmit torque. The clutch can transmit a relatively large amount of torque while the size of a clutch system is reduced as small as possible.

DETAILED DESCRIPTION OF THE DISCLOSURE

Reference will now be made in greater detail to an exemplary embodiment of the present disclosure, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings and the description to refer to the same or like parts.

Referring toFIGS. 1 to 8, a clutch for a vehicle according to an exemplary embodiment of the present disclosure may include: a hub3disposed on a rotary shaft1such that the rotation thereof is restricted; a sleeve5spline-coupled to the outer circumference of the hub3such that the sleeve5can linearly slide in the longitudinal direction of the rotary shaft (hereinafter referred to as the “axial direction”); a clutch member9disposed on the rotary shaft1such that the clutch member9and the rotary shaft1can rotate relative to each other; and a clutch ring7disposed between the clutch member9and the hub3. The clutch ring7may be pressed against the clutch member9by the sleeve5and the hub3such that the clutch ring7transmits torque using frictional force formed between the clutch ring7and the clutch member9.

That is, the hub3and the sleeve5may always rotate integrally with the rotary shaft1, and the clutch member9may be rotatable relative to these components. In this configuration, a torque transmission state may be changed by the clutch function between the clutch ring7and the clutch member9.

The clutch member9can be connected to a rotary body R, such as a gear, that can rotate relative to the rotary shaft1, the hub3and the sleeve5. Consequently, a clutch function realized by the clutch member9and the clutch ring7can change a torque transmission state between a first group including the rotary shaft1, the hub3and the sleeve5and a second group including the clutch member9and the rotary body R.

Although the clutch ring7rotates in concert with the hub3and the sleeve5, the clutch ring7may be movable in the axial direction in the direction of the clutch member9while being rotatable relative to the hub3and the sleeve5to a small angular degree. With this configuration, the clutch ring7can perform the major function of changing the torque transmission state.

The clutch ring7has a pressed part to which an amount of force pressing against the clutch member9is applied from the sleeve5and the hub3. The sleeve5has pressing protrusions13that transfer the axial driving force of the sleeve5to the pressed part. The hub3has displacement converting portions15converting a relative rotational displacement with respect to the clutch ring7into an axial linear displacement of the clutch ring7.

According to a present embodiment, the pressed part of the clutch ring7includes pressed protrusions11protruding radially outward from the outer circumferential surfaces of the clutch ring7. The pressing protrusions13of the sleeve5protrude radially inward from the inner circumferential surfaces of the sleeve5. The hub3has accommodation recesses17in which the pressed protrusions11and the pressing protrusions13are accommodated. The displacement converting portions15are included in the accommodation recesses17.

Each of the accommodation recesses17of the hub3may be configured such that a first recess19into which a corresponding pressing protrusion13is fitted and a second recess21into which a corresponding pressed protrusion11is fitted are connected via a corresponding displacement converting portion15.

The accommodation recesses17may be formed in the outer circumferential surfaces of the hub3, and the pressing protrusions13of the sleeve5and the pressed protrusions11of the clutch ring7may be fitted into the accommodation recesses17, such that the pressing protrusions13and the pressed protrusions11can move in the axial direction.

Thus, when the sleeve5is moved in the axial direction by a predetermined amount of driving force supplied by an actuator, the pressing protrusions13directly transmit the driving force to the pressed protrusions11, whereby the pressed protrusions11move in the axial direction. This consequently increases the amount of torque transmitted during pressing of the clutch ring7against the clutch member9.

The width of the second recess21in the circumferential direction of the hub3may be greater than the width of the first recess19. Each of the displacement converting portions15may be formed as a pair of inclined surfaces, the width of which gradually increases from the first recess19to the second recess21.

Each of the pressed protrusions11of the clutch ring7may have chamfered portions23that are inclined to be parallel with the inclined surfaces of the displacement converting portion15. The width of the second recess21in the circumferential direction may be formed to be greater than the width of the pressed protrusion11in the circumferential direction.

The inclined surfaces of the displacement converting portions15and the chamfered portions23of the pressed protrusions11serve to additionally increase the driving force of the actuator transmitted to the pressed protrusions11via the pressing protrusions13of the sleeve5.

The principle in which the driving force is increased will be discussed with reference toFIG. 7. When driving force F1from the actuator is applied to the pressed protrusions11via the pressing protrusions13, the clutch ring7may start to transmit torque to the clutch member9due to frictional force Ft while being in contact with the clutch member9, whereby the hub3and the clutch7have a relative rotational displacement.

In the case ofFIG. 7, the clutch ring7has a relative rotational displacement with respect to the hub3due to the frictional force Ft directed to the left. Consequently, the chamfered portions23of the pressed protrusion11remaining in contact with the inclined surfaces of the displacement converting portion15are subjected to upwardly-driving force F2, which is combined with the driving force F1, thereby forming Ftotal.

That is, the behavior of the chamfered portions23with respect to the inclined surfaces of the displacement converting portion15may result in the pressed protrusion11moving in the axial direction toward the clutch member9. This consequently acts as additional driving force to bring the clutch ring7into close contact with the clutch member9.

It is thereby possible to realize a large torque transmission capacity using an actuator having, and/or using, less power than that of the related art.

Even in the case in which the clutch ring7is in closest contact with the clutch member9, the chamfered portions23of the pressed protrusion11are required to remain in surface contact with the inclined surfaces of the displacement converting portion15such that the displacement converting portion15can continuously realize the driving force-increasing function.

Thus, even in the case in which the clutch ring7is in closest contact with the clutch member9, it is required that the pressed protrusions11to be spaced apart from both radial side surfaces of the second recesses21.

It is preferable that a plurality of pressed protrusions11, a plurality of pressing protrusions13, and a plurality of accommodation recesses17are symmetrically arranged in the radial direction of the hub3since uniform pressure in the radial direction of the clutch ring7can be applied.

It is preferable that the clutch ring7has a radial clutch surface25, and the clutch member9has a radial clutch surface25such that the radial clutch surfaces25of the clutch ring7and the clutch member9overlap each other, thereby generating the frictional force. This configuration can afford a larger torque transmission capacity than a clutch surface formed as a simple plane.

For reference,FIG. 9illustrates a part of a transmission to which the clutch according to the present disclosure as configured above is applied. The clutch member9rotatably disposed on a first rotary shaft50is connected integrally to a first gear51, which is meshed with a second gear62of a second rotary shaft60. For example, rotational force from the first rotary shaft50is transmitted to the clutch member9via the hub3, the sleeve5, and the clutch ring7. This consequently allows the second gear62to be driven via the first gear51, whereby power can be transmitted to the second rotary shaft60.

Although the exemplary embodiments of the present disclosure have been described for illustrative purposes, a person skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the present disclosure as disclosed in the accompanying claims.