JP2006200626A - Wet brake device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the axial size of a wet brake device by using an annular energizing member for a parking brake operating mechanism. <P>SOLUTION: The wet brake device 107 comprises a brake housing 110 arranged on the outer periphery side of a first axle shaft 61, a friction connection part 120 for braking the rotation of the first axle shaft 61 relative to the brake housing 110 with friction engagement, and the parking brake operating mechanism 130 for giving axial energizing force to the friction connection part 120 to put the friction connection part 120 into friction engagement. The parking brake operating mechanism 130 has an annular pressure plate 131 arranged adjacent to the friction connection part 120, an annular diaphragm spring 132 for energizing the pressure plate 131 against the friction connection part 120 in the axial direction, and an annular parking brake piston 135 using hydraulic pressure for canceling the energizing force of the energizing member. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wet brake device, and more particularly to a wet brake device including a parking brake mechanism.

In recent years, as a brake device for a special work vehicle such as a forklift, a wet brake device considering long life and sealing performance is being adopted instead of a dry brake device. The wet brake device includes, for example, a brake housing disposed on the outer peripheral side of the axle shaft, a friction coupling portion for braking relative rotation of the axle shaft with respect to the brake housing by friction engagement, and an axial direction with respect to the friction coupling portion. A parking brake operating mechanism and a service brake operating mechanism for applying the urging force and frictionally engaging the friction coupling portion. Since this wet brake device is intended to extend the life of a portion where the brake housing is filled with hydraulic oil and frictionally engaged, the friction coefficient at the friction coupling portion is lower than that of the dry brake device. Therefore, the friction coupling portion of the wet brake device secures the braking force against the axle shaft by increasing the number of friction surfaces by using a plurality of annular friction disks or increasing the biasing force against the friction coupling portion (for example, , See Patent Document 1).
JP 2003-247573 A

  In the parking brake operating mechanism of the wet brake device described above, the biasing force in the axial direction to the friction connecting portion is released by supplying the hydraulic pressure, the supply of hydraulic pressure is stopped, and the biasing force in the axial direction is applied to the friction connecting portion. This is a so-called negative brake that generates braking force. Therefore, the braking force at the time of parking is ensured by a plurality of coil springs arranged in the circumferential direction instead of hydraulic pressure (see, for example, FIG. 1 of Patent Document 1). However, if the braking force is secured by the coil spring as described above, the coil spring becomes large, and the accommodation space for the coil spring becomes large. Further, since the urging force by the coil spring is not enough, it is necessary to increase the number of friction surfaces of the friction disk to ensure the braking force, and the accommodation space of the friction coupling portion is increased. As described above, when the coil spring is used to secure the braking force during parking, the axial dimension of the wet brake device is increased, and the axial dimension of the vehicle drive device is also increased.

  Further, in such a wet brake device, since the piston is formed so as to cover the coil spring, it is difficult to provide an oil passage for returning the hydraulic oil that has flowed to the outer peripheral side of the friction coupling portion to the inner peripheral side, The heat dissipating efficiency around the frictional connection is reduced. As a result, the durability of the wet brake device, particularly the friction coupling portion, is reduced.

  The subject of this invention is shortening the axial direction dimension of a wet brake device by devising the structure of a wet brake device.

  Another object of the present invention is to improve the durability of the wet brake device by devising the structure of the wet brake device.

  The wet brake device according to claim 1 is for braking the rotation of the axle shaft of the vehicle. In this wet brake device, a brake housing disposed on the outer peripheral side of the axle shaft, a friction coupling portion for braking relative rotation of the axle shaft with respect to the brake housing by friction engagement, and an axial direction with respect to the friction coupling portion A parking brake operating mechanism for applying an urging force to frictionally engage the friction coupling portion. The parking brake operating mechanism includes an annular pressing member disposed close to the friction coupling portion, an annular biasing member for biasing the pressing member in the axial direction with respect to the friction coupling portion, and biasing by hydraulic pressure. An annular parking brake piston for releasing the biasing force of the member.

  In this wet brake device, since the parking brake operating mechanism has an annular urging member, the axial dimension of the accommodation space can be shortened compared to the case where a coil spring is used as in the prior art. The overall axial dimension can be shortened.

  According to a second aspect of the present invention, the wet brake device according to the first aspect includes an annular portion in which the urging member urges the pressing member, and a plurality of lever portions protruding radially inward from the annular portion. . The parking brake operating mechanism is disposed between the lever portions on the inner peripheral side of the annular portion, and is provided with a plurality of biasing members that are elastically deformable in the axial direction with respect to the brake housing and are not relatively rotatable. It further has a fixing member.

  In this wet brake device, the annular portion on the outer peripheral side of the biasing member biases the pressing member, and the inner peripheral side of the annular portion is supported by the fixing member. By adjusting the position (fulcrum) of the fixing member, it is possible to apply a large urging force while shortening the axial dimension as compared with the conventional case where a coil spring is used. For example, comparing the case where the distance between the fulcrum and the action point is long and the case where the distance between the fulcrum and the action point is long in the same urging member, the urging force acting on the action point is greater when the distance is short. As a result, the number of friction surfaces of the friction coupling portion can be reduced, and the axial dimension of the friction coupling portion can be shortened. Thereby, in this wet brake device, the axial dimension of the whole device can be shortened.

  According to a third aspect of the present invention, in the wet brake device according to the second aspect, the parking brake piston can bias the inner peripheral end of the lever portion in the axial direction.

  In this wet brake device, since the parking brake piston can bias the inner peripheral end of the lever portion in the axial direction, a so-called negative brake can be easily realized.

  According to a fourth aspect of the present invention, there is provided the wet brake device according to any one of the first to third aspects, further comprising a service brake operating mechanism that applies an urging force in an axial direction to the friction coupling portion to frictionally engage the friction coupling portion. I have. The service brake operating mechanism has an annular service brake piston for applying an urging force in the axial direction to the friction coupling portion by hydraulic pressure.

  The wet brake device according to a fifth aspect is the wet brake device according to the fourth aspect, wherein the parking brake operating mechanism is disposed on the opposite side of the service brake operating mechanism with respect to the friction coupling portion.

  In this wet brake device, since the parking brake operating mechanism is disposed on the opposite side of the service brake operating mechanism with respect to the friction coupling portion, a space for providing the service brake operating mechanism can be easily secured.

  A wet brake device according to a sixth aspect is the wet brake device according to the fifth aspect, wherein the inner peripheral portion of the pressing member can abut on the fixed member in the axial direction.

  In this wet brake device, the inner peripheral portion of the pressing member can abut on the fixed member in the axial direction. Therefore, when the axial biasing force is applied from the service brake piston to the friction connecting portion, the pressing member is The urging force can be received by the fixing member.

  A wet brake device according to a seventh aspect is the wet brake device according to the fourth aspect, wherein the parking brake operating mechanism is disposed on the same side as the service brake operating mechanism with respect to the frictional connecting portion.

  In this wet brake device, since the parking brake operating mechanism is disposed on the same side as the service brake operating mechanism with respect to the friction connecting portion, an urging force acts on the friction connecting portion from one direction. Thereby, in this wet brake device, the part which receives urging | biasing force becomes common, and the structure of the part can be simplified.

  The wet brake device according to an eighth aspect of the present invention is the wet brake device according to the seventh aspect, wherein the service brake piston is disposed on the outer peripheral side of the fixed member.

  In this wet brake device, since the service brake piston is arranged on the outer peripheral side of the fixed member, the pressing member can be urged in the axial direction from the outer peripheral side of the urging member.

  According to a ninth aspect of the present invention, in the wet brake device according to any one of the first to eighth aspects, the urging member includes a plurality of plate members.

  In this wet brake device, since the urging member is composed of a plurality of plate members, a larger urging force can be generated by increasing the number of plate members.

  A wet brake device according to a tenth aspect of the present invention further includes a connection hub fixed to the axle shaft in any one of the first to ninth aspects. The friction coupling portion is engaged with a plurality of annular first friction disks engaged with the brake housing so as not to rotate relative to the brake housing and to move in the axial direction, and to move relative to the coupling hub in an axial direction. And a plurality of annular second friction discs that engage with each other.

  A wet brake device according to an eleventh aspect is the wet brake device according to any one of the first to tenth aspects, wherein a plurality of oil grooves formed in the brake housing and extending in the axial direction are arranged on the outer peripheral side of the friction coupling portion.

  In this wet brake device, since the oil groove is disposed on the outer peripheral side of the frictional connection portion, the hydraulic oil that has flowed on the outer peripheral side of the frictional connection portion can be returned to the inner peripheral side through the oil groove. Thereby, compared with the past, the heat dissipation efficiency around the friction coupling portion can be improved, and the durability of the apparatus can be improved.

  According to a twelfth aspect of the present invention, in the wet brake device according to the eleventh aspect, the oil groove is formed on the outer peripheral side inner surface and the axial side surface of the brake housing.

  In this wet brake device, since the oil groove is formed on the outer peripheral side inner surface and the axial side surface of the brake housing, the hydraulic oil is more likely to return to the inner peripheral side. Thereby, compared with the past, the heat dissipation efficiency around the friction coupling portion can be further improved, and the durability of the apparatus can be further improved.

  In the wet brake device according to the present invention, the axial dimension of the device can be shortened by using an annular biasing member or the like for the parking brake operating mechanism.

  Moreover, in the wet brake device according to the present invention, since the heat radiation efficiency around the frictional connection portion is improved, the durability of the device can be improved.

An embodiment of the present invention will be described with reference to the drawings.
<First Embodiment>
1. Overall Configuration of Drive Device FIG. 1 is a sectional view of a drive device equipped with a wet brake device as a first embodiment of the present invention. The drive device 1 includes a housing 2, an electric motor 3, a speed reducer 4, a differential device 5, a pair of axles 6, a pair of wet brake devices 107, and a pair of drive wheels 8. The electric motor 3, the reduction gear 4, and the differential device 5 are accommodated in the housing 2. The electric motor 3 is, for example, an SR motor (Switched Reluctance Motor) or the like, and is fixed inside the housing 2. The reduction gear 4 is for reducing the rotation output from the electric motor 3 and is connected to the output side of the electric motor 3. The differential device 5 is for separately transmitting the rotation output from the reduction gear 4 to the left and right drive wheels 8 and for adjusting the rotational difference of the drive wheels 8, and is connected to the output side of the reduction gear 4. ing. The axle 6 is for supporting the drive wheel 8 so as to be rotatable relative to the housing 2 while transmitting the rotation output from the differential device 5 to the left and right drive wheels 8. It is arrange | positioned so that it may extend. A wet brake device 107 for braking the rotation transmitted from the axle 6 to the drive wheels 8 is provided on the outer peripheral side of the axle 6.

2. FIG. 2 shows a cross-sectional view around the reduction gear. Hereinafter, the configuration of each unit will be described in detail with reference to FIG.

(1) Electric motor The electric motor 3 includes a stator 31, a rotor 32, and a drive shaft 33. The stator 31 is a cylindrical member provided on the outer peripheral side, and is fixed to the housing 2. A cylindrical rotor 32 is disposed on the inner peripheral side of the stator 31 so as to be relatively rotatable. A cylindrical drive shaft 33 extending in the axial direction is fixed to the inner peripheral side of the rotor 32 so as not to be relatively rotatable. An annular motor cover 35 fixed to the housing 2 is provided on the reduction gear 4 side of the electric motor 3. The motor cover 35 is for partitioning the space between the electric motor 3 side and the speed reduction device 4 and the differential device 5 side, and the space on the speed reduction device 4 side is filled with hydraulic oil.

(2) Reduction gear The reduction gear 4 is mainly composed of a first reduction gear 40 and a second reduction gear 44. The first reduction gear 40 is for reducing the rotation of the drive shaft 33 of the electric motor 3, and mainly includes a plurality of first planetary gears 41, a first ring gear 45, a first carrier 42b, and a connecting member 42a. It is composed of

  The first planetary gear 41 is disposed circumferentially on the outer peripheral side of the drive shaft 33 and meshes with an input sun gear 33 a provided on the outer peripheral side of the end of the drive shaft 33. The first ring gear 45 is an annular member provided on the outer peripheral side of the plurality of first planetary gears 41 and meshes with the first planetary gear 41. The first ring gear 45 is fixed to the housing 2. The first carrier 42 b is an annular member for connecting a plurality of first pins 41 a provided respectively inside the first planetary gear 41 in the circumferential direction. The connecting member 42a is an annular member for connecting the plurality of first pins 41a in the circumferential direction, and is disposed on the opposite side of the first planetary gear 41 from the first carrier 42b. The movement of the connecting member 42a toward the axial motor 3 side (left side in FIG. 2) is restricted by a thrust bearing 35a provided on the motor cover 35 fixed to the housing 2. A first sun gear 43 extending in the axial direction is fixed to the inner peripheral side of the first carrier 42b.

  The second reduction gear 44 is for further reducing the rotation output from the first reduction gear 40, and mainly comprises a plurality of second planetary gears 46, a second ring gear 48, and a second carrier 47. Has been.

  The second planetary gear 46 is provided on the outer peripheral side of the first sun gear 43 of the first reduction gear 40 and meshes with the first sun gear 43. The second ring gear 48 is an annular member provided on the outer peripheral side of the plurality of second planetary gears 46 and meshes with the second planetary gears 46. The second ring gear 48 is fixed to the housing 2. The second carrier 47 is an annular member for connecting a plurality of second pins 46 a respectively provided in the second planetary gear 46 in the circumferential direction.

(3) Differential Device The differential device 5 mainly includes a third ring gear 54, a plurality of third planetary gears 53, a third carrier 51, a third sun gear 52, and a fourth carrier 56. Yes.

  The third ring gear 54 is a cylindrical member fixed to the outer peripheral side of the second carrier 47 of the second reduction gear 44. The third planetary gear 53 is arranged in the circumferential direction so as to mesh with the inner peripheral side of the third ring gear 54. The third carrier 51 is an annular member for connecting a plurality of third pins 53 a respectively provided in the third planetary gear 53 in the circumferential direction. The third carrier 51 is connected to the second carrier 47 by the first bearing 55. It is supported for relative rotation. The third sun gear 52 is disposed on the inner peripheral side of the plurality of third planetary gears 53 and meshes with the third planetary gears 53. The third sun gear 52 is fixed to the outer peripheral side of the second axle shaft 62. Further, on the opposite side of the third planetary gear 53 from the third carrier 51, a fourth carrier 56 is provided so as to connect the plurality of third pins 53a in the circumferential direction. The fourth carrier 56 is fixed to the outer peripheral side of the first axle shaft 61 and is supported by the second bearing 63 so as to be relatively rotatable with respect to the first support member 64 fixed to the housing 2.

3. FIG. 3 is a cross-sectional view around the wet brake device according to the first embodiment of the present invention. In FIG. 3, the electric motor 3 is arranged on the left side. Hereinafter, the configuration of each unit will be described in detail with reference to FIG.

  The wet brake device 107 is disposed on the outer peripheral side of the axle 6, and mainly includes a brake housing 110, a connection hub 150, a frictional connection portion 120, a parking brake operation mechanism 130, and a service brake operation mechanism 140. It is configured.

(1) Brake Housing The brake housing 110 is for housing the friction coupling part 120, the parking brake operating mechanism 130, and the service brake operating mechanism 140 inside, and is disposed on the outer peripheral side of the first support member 64 of the axle 6. ing. The brake housing 110 includes a first brake housing 111 and a second brake housing 112.

  The first brake housing 111 is an annular member disposed on the outer peripheral side of the axle 6, and is fixed to the frame support 21 to which the housing 2 is connected by a plurality of first bolts 118. The first brake housing 111 has a plurality of first protrusions 111a that are arranged in the circumferential direction and can contact a diaphragm spring 132 described later. The second brake housing 112 is an annular member disposed on the axial drive wheel 8 side (right side in FIG. 3) of the first brake housing 111, and is fixed to the first brake housing 111 by the second bolt 117. ing. Further, the inside of the brake housing 110 is filled with hydraulic oil, and is sealed by a first seal member 116 provided on the inner peripheral side on the drive wheel 8 side.

  A plurality of oil grooves 119 arranged in the circumferential direction and extending in the axial direction are provided on the inner peripheral side of the first brake housing 111 in order to promote the flow of hydraulic oil around the frictional coupling portion 120. The oil groove 119 is formed on the side surface in the axial direction of the first brake housing 111 to the periphery of a diaphragm spring 132 described later. As a result, the hydraulic oil that has moved to the outer peripheral side of the frictional connection part 120 can be returned to the inner peripheral side through the gap around the diaphragm spring 132, and the heat dissipation efficiency around the frictional connection part 120 can be improved. . And the durability of the wet brake device 107 can be improved as compared with the prior art.

(2) Connection Hub The connection hub 150 is for connecting the first axle shaft 61, the drive wheel 8, and the friction connecting portion 120, and is relatively rotated by a third bearing 65 provided at the tip of the first support member 64. It is supported so that it cannot move relative to the axial direction. The connection hub 150 is fixed to the end portion of the first axle shaft 61 with a third bolt 151. The drive wheel 8 is fixed to the connection hub 150 by a fourth bolt 152. A cylindrical portion 155 extending inside the brake housing 110 is formed on the axial direction motor 3 side (left side in FIG. 3) of the connecting hub 150. On the outer peripheral side of the cylindrical portion 155, a plurality of second external teeth 153 are formed that are arranged in the circumferential direction, protrude outward in the radial direction, and extend in the axial direction. Further, the cylindrical portion 155 is provided with a plurality of first holes 154 in order to promote the flow of hydraulic oil around the friction coupling portion 120 described later.

(3) Friction connecting portion The friction connecting portion 120 is for braking relative rotation between the brake housing 110 and the first axle shaft 61 by friction engagement, and is disposed on the inner peripheral side of the first brake housing 111. Yes. The friction coupling part 120 includes a plurality of first friction disks 121 and a plurality of second friction disks 123.

  The first friction disk 121 is an annular member that is disposed in the axial direction and engages with the brake housing 110 so as not to rotate relative to the brake housing 110 and to be relatively movable in the axial direction. Specifically, a plurality of first external teeth 122 arranged in the circumferential direction and projecting outward in the radial direction are formed on the outer peripheral side of the first friction disk 121. A plurality of first internal teeth 113 are formed on the inner peripheral side of the first brake housing 111 so as to be disposed in the circumferential direction, project inward in the radial direction, and extend in the axial direction. A plurality of first friction disks 121 are arranged so that the first external teeth 122 engage with the first internal teeth 113.

  The second friction disk 123 is disposed between the adjacent first friction disks 121 and between the first friction disk 121 and the second brake housing 112 so that it cannot rotate relative to the first axle shaft 61. And it is the annular member engaged so that relative movement is possible to an axial direction. Specifically, on the inner peripheral side of the second friction disk 123, a plurality of second internal teeth 124 that are arranged in the circumferential direction and project inward in the radial direction are formed. A plurality of second friction disks 123 are arranged so that the second inner teeth 124 engage with the second outer teeth 153 of the connection hub 150. A plurality of second holes 125 are formed on the inner peripheral side of the second friction disk 123 in order to promote the flow of hydraulic oil.

(4) Parking brake operating mechanism The parking brake operating mechanism 130 is for braking the rotation transmitted from the axle 6 to the drive wheels 8 to place the vehicle in a parking state. Specifically, the parking brake operating mechanism 130 is for applying an axial urging force to the friction coupling portion 120 to frictionally engage the friction coupling portion 120. Arranged on the side. The parking brake operating mechanism 130 mainly includes a pressure plate 131 (pressing member), a diaphragm spring 132 (biasing member), two rings 133, a plurality of stop pins 134 (fixing members), and a parking brake piston 135. And a parking hydraulic chamber 136. FIG. 3 shows a state where the urging force of the diaphragm spring 132 is released, that is, a state where the parking brake is not operated.

  The pressure plate 131 is an annular member disposed in the vicinity of the friction coupling portion 120. The pressure plate 131 is disposed so as not to rotate relative to the first brake housing 111 and to be relatively movable in the axial direction. Specifically, on the outer peripheral side of the pressure plate 131, a plurality of third external teeth 131b arranged in the circumferential direction and protruding outward in the radial direction are formed. Similar to the first friction disk 121, the pressure plate 131 is arranged so that the third external teeth 131 b engage with the first internal teeth 113.

  In addition, an inner peripheral portion 131c having an axial thickness smaller than that of the outer peripheral side is provided on the inner peripheral side of the pressure plate 131, and can be brought into contact with the stop pin 134 in the axial direction. By providing the inner peripheral portion 131c, the axial dimension of the parking brake operating mechanism 130 can be further shortened, and the urging force in the axial direction from the service brake operating mechanism 140 is received by the stop pin 134 via the pressure plate 131. be able to. Further, the pressure plate 131 is arranged in the circumferential direction and has a plurality of second protrusions 131 a for receiving a biasing force from the diaphragm spring 132.

  The diaphragm spring 132 is an annular member disposed on the axial motor 3 side of the pressure plate 131 for biasing the pressure plate 131 in the axial direction with respect to the friction coupling portion 120. In this embodiment, the diaphragm spring 132 is composed of two plates. The diaphragm spring 132 is supported so as to be elastically deformable in the axial direction with respect to the first brake housing 111 and not relatively rotatable. The diaphragm spring 132 is set in a state where the pressure plate 131 is urged toward the axial drive wheel 8 side. The diaphragm spring 132 includes an annular portion 132a and a plurality of lever portions 132b.

  The annular portion 132 a is for urging the pressure plate 131 and is formed on the outer peripheral side of the diaphragm spring 132. The lever part 132b is a part protruding radially inward from the annular part 132a. A stop pin 134 is disposed between the lever portions 132b on the inner peripheral side of the annular portion 132a. A head 134 a having a larger outer diameter than the main body 134 b is formed at the tip of the stop pin 134, and a diaphragm spring 132 is sandwiched together with the ring 133 between the head 134 a and the first brake housing 111 in the axial direction. It is. With these configurations, the diaphragm spring 132 is supported so as to be elastically deformable in the axial direction with the contact portion with the ring 133 as a fulcrum and not to rotate relative to the first brake housing 111.

  The parking brake piston 135 is an annular member for releasing the urging force of the diaphragm spring 132 by hydraulic pressure, and is inserted into the annular first recess 114 provided in the first brake housing 111 in the axial direction. An annular parking hydraulic chamber 136 is formed between the parking brake piston 135 and the first recess 114 in the axial direction, and is sealed by two second seal members 137 provided on the parking brake piston 135. An oil passage (not shown) is connected to the parking hydraulic chamber 136, and, for example, hydraulic pressure can be supplied from a hydraulic pump (not shown) driven by the electric motor 3 through the oil passage. The first recess 114 is provided with a snap ring 138 for restricting the stroke of the parking brake piston 135. The parking brake piston 135 can bias the inner peripheral end of the lever portion 132b of the diaphragm spring 132.

  As described above, by using the diaphragm spring 132, it is possible to apply a larger urging force to the friction coupling portion 120 than in the case where the coil spring is used as in the conventional case, and the friction surface can be reduced. . Further, the axial dimension of the diaphragm spring 132 can be shortened compared to the coil spring. Thereby, the axial dimension of the wet brake device 107 can be shortened.

(5) Service brake operation mechanism The service brake operation mechanism 140 is for braking the rotation transmitted from the axle 6 to the drive wheels 8 to decelerate and stop the traveling vehicle. Specifically, the service brake operation mechanism 140 is for applying an urging force in the axial direction to the friction coupling portion 120 by hydraulic pressure to frictionally engage the friction coupling portion 120. It is arranged on the drive wheel 8 side. The service brake operation mechanism 140 mainly includes a service brake piston 141 and a service hydraulic chamber 142. FIG. 3 shows a state where the service brake is not operating.

  The service brake piston 141 is an annular member for urging the friction coupling portion 120 in the axial direction, and is inserted into an annular second recess 115 provided in the second brake housing 112 in the axial direction. An annular service hydraulic chamber 142 is formed between the service brake piston 141 and the second recess 115 in the axial direction, and is sealed by two third seal members 143 provided on the service brake piston 141. An oil passage (not shown) is connected to the service hydraulic chamber 142, and for example, hydraulic pressure can be supplied from the hydraulic pump (not shown) driven by the electric motor 3 through the oil passage.

  In addition, an axial surface 141 a is provided on the outer peripheral side of the service brake piston 141, and can contact the axial surface 115 a of the second recess 115. In this case, the service hydraulic chamber 142 can be secured by the contact of the axial surfaces 141a and 115a, and the axial urging force is applied to the second brake housing 112 and the service brake piston 141 when the parking brake operating mechanism 130 is operated. Can be received at.

4). Operation The operation of the wet brake device 107 will be described.

(1) Operation of parking brake operating mechanism The operation of the parking brake operating mechanism 130 will be described with reference to FIG.

  In the parking state, the diaphragm spring 132 urges the pressure plate 131 in the axial direction, and the friction coupling portion 120 is held between the pressure plate 131, the second brake housing 112 and the service brake piston 141. As a result, the first friction disk 121 and the second friction disk 123 are frictionally engaged, and the relative rotation between the brake housing 110 and the connecting hub 150 is braked by the frictional force generated on each friction surface. Thereby, the rotation of the first axle shaft 61 and the drive wheel 8 is also braked, and the vehicle is parked.

  When canceling the parking state, hydraulic pressure is supplied to the parking hydraulic chamber 136, and the parking brake piston 135 urges the inner peripheral end of the lever portion 132b of the diaphragm spring 132 toward the axial drive wheel 8. As a result, the diaphragm spring 132 is elastically deformed in the axial direction with the stop pin 134 as a fulcrum, and the annular portion 132a moves to the axial direction motor 3 side. Thereby, the urging force to the pressure plate 131 is released, and the frictional engagement between the first friction disk 121 and the second friction disk 123 is released. Then, as shown in FIG. 3, the parking state is released, and the vehicle can travel.

  When the parking state is set again from this state, the supply of hydraulic pressure to the parking hydraulic chamber 136 is stopped. As a result, the biasing force of the parking brake piston 135 to the inner peripheral end of the lever portion 132b is released, and the diaphragm spring 132 returns to its original state. As a result, the vehicle is parked.

(2) Operation of Service Brake Actuation Mechanism The operation of the service brake actuation mechanism 140 will be described with reference to FIG.

  When it is desired to decelerate and stop while the vehicle is traveling, the hydraulic pressure is supplied to the service hydraulic chamber 142. As a result, the service brake piston 141 moves to the axial direction motor 3 side. At this time, since the pressure plate 131 is restricted from moving toward the axial motor 3 by the stop pin 134 and the first protrusion 111a, the friction connecting portion 120 is narrow between the service brake piston 141 and the pressure plate 131. Be held. As a result, the first friction disk 121 and the second friction disk 123 are frictionally engaged, and the rotation of the drive wheels 8 is braked. Regarding the service brake operation mechanism 140, the hydraulic pressure supplied to the service hydraulic chamber 142 can be adjusted, and the level of the hydraulic pressure changes depending on the strength of the brake pedal operation by the driver. For this reason, the braking force generated in the frictional coupling portion 120 can be adjusted by the degree of depression of the brake pedal of the driver.

5. Effects The effects of the dual clutch device according to the present invention are summarized below.

-Shortening of axial dimension In this wet brake device 107, since the parking brake operating mechanism 130 has an annular diaphragm spring 132, the axial dimension of the accommodation space compared to the conventional case using a coil spring. Can be shortened.

  Further, since the annular portion 132a on the outer peripheral side of the diaphragm spring 132 urges the pressure plate 131 and the inner peripheral side of the annular portion 132a is fixed by the stop pin 134, the position (operation point) for urging the pressure plate 131 By adjusting the position of the stop pin 134 and the position (fulcrum) of the stop pin 134, a larger urging force than that of the conventional coil spring can be applied, and the friction surface can be reduced. As a result, the axial dimension of the accommodation space of the friction coupling part 120 can be shortened.

  As described above, in this wet brake device 107, the axial dimension of the entire device can be shortened.

(2) Improvement of durability In this wet brake device 107, the oil groove 119 is disposed on the outer peripheral side of the friction coupling portion 120, so that the hydraulic oil that has flowed to the outer peripheral side of the friction coupling portion 120 passes through the oil groove 119. Can be returned to the inner periphery. Thereby, compared with the past, the heat dissipation efficiency around the friction coupling portion 120 can be improved, and the durability of the wet brake device 107 can be improved.

Second Embodiment
In the above-described first embodiment, the parking brake operation mechanism 130 is disposed on the opposite side of the service brake operation mechanism 140 with respect to the friction coupling portion 120, but may be disposed on the same side. Specifically, as shown in FIG. 4, the parking brake operation mechanism 230 may be disposed on the same side as the parking brake operation mechanism 230 with respect to the frictional connection part 220.

  In this case, the service brake piston 241 is disposed on the outer peripheral side of the stop pin 234. On the outer peripheral side of the service brake piston 241, a plurality of pressing portions 242 that are arranged in the circumferential direction and extend in the axial direction are formed. The pressing portion 242 can bias the outer peripheral side of the pressure plate 231 through the outer peripheral side of the diaphragm spring 232.

  An oil groove 219 is formed on the inner peripheral side of the brake housing 210 as in the first embodiment. Specifically, the oil groove 219 is formed on the inner peripheral surface of the first brake housing 211 and the side surface in the axial direction of the second brake housing 212.

  With these configurations, in this wet brake device 107, since the frictional coupling part 220 is urged only from one direction, the parking brake operating mechanism 230 and the service brake operating mechanism 240 can share a portion that receives the urging force. In addition, the portion receiving the biasing force, that is, the structure of the second brake housing 212 can be simplified.

  In addition, since the oil groove 219 can be formed in a wider range than in the first embodiment, the heat dissipation efficiency around the frictional connection part 220 is further improved, and the durability of the apparatus can be improved.

  Since the operation of the wet brake device 207 is not different from that of the first embodiment, the description thereof is omitted.

<Other embodiments>
The present invention is not limited to the above-described embodiment, and various changes or modifications can be made without departing from the scope of the present invention.

(1) Drive Device In the above-described embodiment, the single-shaft type drive device 1 using the electric motor 3 (SR motor) as the power source has been described as an example. However, the wet brake device according to the present invention is a forklift drive device. If so, other types can be mounted. For example, it may be a two-axis type drive device equipped with an engine and a torque converter.

(2) Diaphragm spring In the above-described embodiment, the diaphragm springs 132 and 232 are described as being composed of two plates. However, the present invention is not limited to this.

(3) Connection hub In the above-mentioned embodiment, although the connection hub 150 is included in the structure of the wet brake devices 107 and 207, it is not limited to this.

Sectional drawing of the drive device carrying the wet brake device 107 as 1st Embodiment of this invention. Sectional drawing around a reduction gear. Sectional drawing of the wet brake device 107 periphery as 1st Embodiment of this invention. Sectional drawing of the wet brake device 207 periphery as 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive device 2 Housing 3 Electric motor 4 Deceleration device 5 Differential device 6 Axle 8 Drive wheel 107, 207 Wet brake device 110, 210 Brake housing 119, 219 Oil groove 120, 220 Friction connection part 130, 230 Parking brake operation mechanism 131, 231 Pressure plate (pressing member)
132, 232 Diaphragm spring (biasing member)
134, 234 Stop pin (fixing member)
135 Parking brake piston 140, 240 Service brake operating mechanism 150 Connecting hub

Claims (12)

A wet brake device for braking rotation of a vehicle axle shaft,
A brake housing disposed on the outer peripheral side of the axle shaft;
A friction coupling portion for braking relative rotation of the axle shaft with respect to the brake housing by friction engagement;
A parking brake operating mechanism for applying an axial urging force to the friction coupling portion to frictionally engage the friction coupling portion;
The parking brake operating mechanism includes an annular pressing member disposed in proximity to the friction coupling portion, an annular biasing member for biasing the pressing member in the axial direction with respect to the friction coupling portion, A wet brake device having an annular parking brake piston for releasing the urging force of the urging member by hydraulic pressure. The urging member has an annular portion that urges the pressing member, and a plurality of lever portions that protrude radially inward from the annular portion,
The parking brake operating mechanism is disposed between the lever portions on the inner peripheral side of the annular portion, and the biasing member is elastically deformable in the axial direction with respect to the brake housing and is not relatively rotatable. It further has a plurality of fixing members for supporting,
The wet brake device according to claim 1. The parking brake piston can bias the inner peripheral end of the lever portion in the axial direction.
The wet brake device according to claim 2. A service brake operating mechanism for applying an axial urging force to the friction coupling portion to frictionally engage the friction coupling portion;
The service brake operating mechanism has an annular service brake piston for applying an urging force in the axial direction to the friction coupling portion by hydraulic pressure.
The wet brake device according to any one of claims 1 to 3. The parking brake operating mechanism is disposed on the opposite side of the service brake operating mechanism with respect to the friction coupling portion.
The wet brake device according to claim 4. The inner peripheral portion of the pressing member can contact the fixing member in the axial direction.
The wet brake device according to claim 5. The parking brake operating mechanism is disposed on the same side as the service brake operating mechanism with respect to the friction coupling portion.
The wet brake device according to claim 4. The service brake piston is disposed on the outer peripheral side of the fixed member,
The wet brake device according to claim 7. The biasing member is composed of a plurality of plate members.
The wet brake device according to any one of claims 1 to 8. A connecting hub fixed to the axle shaft;
The friction coupling portion is
A plurality of annular first friction disks engaged with the brake housing so as not to rotate relative to the brake housing and to move relative to each other in the axial direction;
A plurality of annular second friction disks engaged with the connecting hub so as not to rotate relative to the connecting hub and to be relatively movable in the axial direction;
The wet brake device according to any one of claims 1 to 9. A plurality of oil grooves extending in the axial direction formed in the brake housing are arranged on the outer peripheral side of the friction coupling portion,
The wet brake device according to any one of claims 1 to 10. The oil groove is formed on an outer peripheral side inner surface and an axial side surface of the brake housing.
The wet brake device according to claim 11.

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