CN210799811U

CN210799811U - Wet-type multi-plate clutch of working vehicle and vehicle steering transmission device comprising same

Info

Publication number: CN210799811U
Application number: CN201920896228.1U
Authority: CN
Inventors: 黄轸皓
Original assignee: Daido Kogyo Co Ltd
Current assignee: Daido Kogyo Co Ltd
Priority date: 2018-06-14
Filing date: 2019-06-14
Publication date: 2020-06-19
Anticipated expiration: 2029-06-14
Also published as: KR20190141449A; KR102553639B1

Abstract

The utility model discloses an operation vehicle wet-type multiplate clutch reaches vehicle steering transmission including it, wet-type multiplate clutch install in have can drive about individually a pair of crawler-type running gear's gearbox, power transmission between a pair of crawler-type running gear and the engine about intermediate control. The wet-type multiplate clutch includes: an output shaft of a hollow structure integrally having a clutch hub; a clutch housing attached to a brake cover of the transmission case and surrounding the clutch hub at the front end of the output shaft; a friction element including a plurality of pairs of first friction plates and second friction plates alternately arranged between a clutch hub and a clutch housing; and a pressure plate which is spline-coupled to an inner periphery of the clutch housing so as to be slidable, wherein the urging member is attached to an outer periphery of the clutch hub, and wherein an annular disc spring which is elastically deformable in compression is attached between the urging member and the pressure plate.

Description

Wet-type multi-plate clutch of working vehicle and vehicle steering transmission device comprising same

Technical Field

The utility model relates to a wet-type multiplate clutch of work vehicle especially relates to a wet-type multiplate clutch of work vehicle and including its vehicle steering transmission, and wet-type multiplate clutch is installed in the gearbox of the work vehicle who has left and right sides a pair of crawler-type running gear, controls in the middle power transmission between running gear and the engine.

Background

A work vehicle that continuously performs a series of processes of harvesting crops while traveling, screening and separating grains and straws from the harvested crops, and temporarily storing the screened grains is called a combine harvester. A combine harvester generally includes a harvesting unit, a threshing unit, a straw discharge unit, a grain tank, and the like, and a crawler type traveling device is used for a vehicle mainly performing a wet field work in which a ground surface is soft, for characteristic reasons.

Crawler belt (Crawler) traveling devices have an extremely large ground contact area and a low ground contact pressure applied to a ground contact surface, as compared with tire-type traveling devices, and have the advantage of being easy to travel even on a dangerous road or a soft or weak ground. Therefore, the traveling device is very useful for an agricultural work vehicle such as a combine harvester mainly performing a wet field work in which a ground contact object surface is soft.

In general, a crawler traveling apparatus used in a combine can drive agile steering according to working conditions such as a cut-off steering (Brake turn), a center steering (Spin turn), and a differential steering (Soft turn) by a transmission configured to be able to intermittently supply power generated by an engine to left and right crawler traveling apparatuses after changing a speed according to traveling or work.

For reference, the differential steering (Soft turn) is a steering in which the vehicle body is steered at a large radius by applying a difference in steering speed between a pair of left and right crawler type traveling devices, and the trim steering (Brake turn) is a steering in which the vehicle body is steered only by one of the other side traveling devices in a state in which the driving of the one side traveling device is suppressed. The center turn (Spin turn) is a vehicle body turn that is achieved by reversing the turning directions of the two running gears.

A transmission of a work vehicle having a crawler type traveling device is provided with a steering transmission device that realizes the aforementioned various vehicle body steering by interrupting power transmission between the pair of left and right traveling devices and the engine. A steering transmission device applied to a work vehicle (for example, a combine) having a conventional crawler type traveling device may have a structure disclosed in, for example, patent document 1 below.

The steering transmission device of patent document 1 includes: a support shaft mounted to the transmission case and having a sun gear; and a pair of right and left small-diameter clutch gears which are externally mounted on the support shafts so as to be relatively rotatable on both right and left sides of the sun gear, and which are respectively and independently engaged with a pair of right and left travel transmission gears connected to the pair of right and left crawler travel devices, respectively, and which are relatively movable along the support shafts.

In the multi-plate clutch of the steering transmission described in patent document 1, when the first friction plate and the second friction plate are arranged without a gap and are in contact with each other, a completely integrated state of the two friction plates by the friction force of the two friction plates is a clutch engaged state, and conversely, a state in which the first friction plate and the second friction plate are separated and do not interfere with each other is a clutch disengaged state. In addition, there is a half clutch state in which the two friction plates rotate relative to each other although they are in contact with each other.

If the left and right crawler-type traveling devices are in the half-engaged state, a difference in steering speed occurs between the left and right crawler-type traveling devices and the other crawler-type traveling device in the clutch-disengaged state (the steering speed of the left and right crawler-type traveling devices is relatively slow), and the above-described differential steering (Softturn) is realized in which the vehicle body is largely steered in the direction of the left and right crawler-type traveling devices in the half-engaged state.

However, in the case of a conventional multiple disc clutch including a plurality of friction elements (first and second friction plates) alternately arranged as in the case of the conventional multiple disc clutch disclosed in patent document 1, a movement pressing portion (a member pressing the friction elements) attached to the small-diameter clutch gear may also be inclined with respect to a support shaft as a concentric shaft because the small-diameter clutch gear is inclined with respect to the support shaft due to a machining error between the respective members.

In such a state where the moving pressing portion is inclined with respect to the support shaft, if the half clutch state is established, there is a problem that noise is generated due to the heavy contact between the friction plate closest to the moving pressing portion and the moving pressing portion. Even if the small-diameter clutch gear is not inclined with respect to the support shaft, the pressing surface of the movable pressing portion may be uneven, which may cause uneven contact and noise.

[ Prior Art document ]

[ patent document ]

(patent document 1) Japanese laid-open patent No. 2007-303637 (Kokai No. 2007.11.22)

SUMMERY OF THE UTILITY MODEL

The technical problem to be solved by the present invention is to provide a wet-type multiplate clutch for a working vehicle and a vehicle steering transmission device including the same, in which, in a half clutch state, the contact between a friction element and a movable element (pushing member) pressing the friction element is kept good without being inclined to a certain side, and abnormal noise is not generated.

As a technical solution, according to an aspect of the present invention,

provided is a wet-type multiplate clutch for a work vehicle, which is mounted to a transmission of the work vehicle having a pair of left and right crawler-type traveling devices that can be individually driven, and which controls power transmission between the pair of left and right crawler-type traveling devices and an engine in the middle, the wet-type multiplate clutch comprising:

an output shaft of a hollow structure integrally having a clutch hub;

a clutch housing attached to a brake cover of the transmission case and surrounding the clutch hub at a front end of the output shaft;

a friction element including a plurality of pairs of first friction plates and second friction plates alternately arranged between the clutch hub and the clutch housing;

a pressure plate that is spline-coupled to an inner periphery of the clutch housing so as to be slidable, and presses or releases the friction element in accordance with linear motion of the output shaft relative to the input shaft; and

a pushing member attached to an outer periphery of the clutch hub and linearly moving together with the output shaft in a direction of pressing or separating the pressure plate;

between the urging member and the pressure plate, a compression-elastically deformable annular disc spring is mounted.

Wherein a snap ring may be installed in the open-side groove of the clutch housing, and the disc spring is prevented from being separated from the clutch housing by the snap ring.

In addition, the annular disc spring may be configured such that an inner edge portion having a relatively small diameter is attached to the urging member and moves together with the urging member, and an outer edge portion having a relatively large diameter is projected toward the pressure plate.

Preferably, an overlapping step may be formed at an outer periphery of the urging member on a side opposite to the pressure plate, to which an inner edge portion of the disc spring overlaps.

The output shaft may be disposed concentrically outside the input shaft that rotates by the power of the engine so as to be relatively rotatable, and may be disposed so as to be linearly movable along the input shaft in accordance with the operation of the clutch operation arm.

In addition, an elastic member may be interposed between the input shaft and the clutch hub, and the elastic member may provide a restoring force to the output shaft in a direction in which the clutch engagement is released.

As a technical solution, according to another aspect of the present invention,

provided is a work vehicle steering transmission device, wherein the work vehicle is provided with a pair of left and right crawler-type traveling devices that are individually drivable based on operation of a steering mechanism, and the work vehicle steering transmission device is characterized by comprising:

an input shaft rotatably attached to the transmission case and configured to receive engine power transmitted through an input gear and rotate;

a pair of wet-type multi-plate clutches which are provided on the left and right sides with the input gear as the center so as to interrupt the power transmission between the pair of left and right crawler-type traveling devices and the engine at the middle;

the output shafts of the pair of left and right wet-type multiplate clutches are concentrically disposed outside the input shaft so as to be relatively rotatable on both left and right sides of the input gear, and are relatively moved along the input shaft by the operation of a clutch operating arm,

each of the output shafts is formed with a clutch gear that is constantly engaged with a pair of left and right drive transmission gears connected to the pair of left and right crawler travel devices, respectively, and that is capable of being individually engaged with the input gear when the output shaft is relatively moved along the input shaft by operation of the steering mechanism.

According to the utility model discloses wet-type multiplate clutch of work vehicle and steering transmission of work vehicle, install the annular disc spring that can compress elastic deformation between the pressure plate of the pushing component that carries out linear motion along input shaft and output shaft together with oppression friction factor.

Therefore, due to machining errors between the components constituting the clutch, even if the output shaft that performs linear motion on the input shaft as a concentric shaft is slightly inclined with respect to the input shaft when the clutch contact is attempted, the force of the urging member pressing the pressure plate can be uniformly input to the pressure plate without being biased to one side.

Therefore, even in the half-clutch state, the contact between the friction element and the movable element (pushing member) pressing the friction element can be kept good without being biased to one side, and as a result, the conventional problem of abnormal noise caused by the biased contact between the friction element and the movable element in the half-clutch state can be solved.

Drawings

Fig. 1 and 2 are side views of a work vehicle (combine) including a work vehicle steering transmission according to an embodiment of the present invention, as viewed from the right side and the left side, respectively.

Fig. 3 is a plan view of the work vehicle shown in fig. 1 and 2.

Fig. 4 is a conceptual diagram of a threshing/screening device of a harvester for threshing and screening crops supplied from a harvesting unit.

Fig. 5 is a sectional view of a steering transmission according to an embodiment of the present invention.

Fig. 6 is an enlarged view of a main portion of the wet multiple disk clutch on the left side of fig. 5.

FIG. 7 is a diagram of the clutch operating state of the present invention;

fig. 8 is a clutch engagement operating state diagram according to the present invention.

[ reference numerals ] of the drawings

1: a vehicle body 3: harvesting part

4: a feeder 6: spiral drill

7: vehicle body operation unit (driver seat) 8: threshing/screening device

9: grain box 10: engine

11: the dust cap assembly 14: vehicle body frame

20L, 20R: the traveling device 30: steering transmission device

31L, 31R: clutch operation arm 32: input shaft

33:

input gears

34L, 34R: wet-type multiplate clutch

36:

elastic members

39L, 39R: drive transmission gear

340L, 340R: output shaft 341: clutch hub

342: clutch housing 343: clutch gear

344: friction element 344-1: first friction plate

344-2: second friction plate 346: pressure plate

347: belleville spring 348: pushing component

349: snap ring A: step

B: bearing BC: brake cover

MC: gear box

Detailed Description

The preferred embodiments of the present invention are described in detail below. In describing the present invention, detailed description of known configurations will be omitted, and detailed description of configurations that may unnecessarily obscure the gist of the present invention will be omitted.

Fig. 1 and 2 are side views of a work vehicle (combine) including a work vehicle steering transmission according to an embodiment of the present invention, as viewed from the right side and the left side, respectively, and fig. 3 is a plan view of the work vehicle shown in fig. 1 and 2. Referring to these drawings, first, the overall structure of the work vehicle is examined roughly.

As shown in fig. 1 to 3, a harvester according to an embodiment of the present invention is generally configured by a vehicle body 1 and a harvesting unit 3 in front of the vehicle body 1. The vehicle body 1 includes crawler

type traveling devices

20L and 20R each including a crawler belt, and the harvesting unit 3 is connected to the traveling vehicle body 1 so as to be able to ascend and descend via a harvesting unit frame 32 attached to a front end of the traveling vehicle body 1 so as to incline forward and downward.

The harvesting unit 3 includes 2 sets (2 sets are exemplarily shown in fig. 3, but may be configured as 2 or more sets) of pusher-type (harvester type) harvesters having opposite operation directions, and crops harvested by the harvester are safely transported to a Feeder (Feeder)4 on the vehicle body 1 side by a transport device (configured by attaching a transport rod that is expanded when being moved upward to a rotary chain) configuring the harvesting unit 3, and are moved to a threshing/sorting device 8 on the vehicle body 1 side by the Feeder 4.

The ears of crops are threshed while passing through a threshing/screening device 8, a screening operation for filtering chaff, straw, and the like included together with grains of the threshed crops is performed, and the grains finally screened by the screening operation are conveyed to a grain tank 9 on the inner side of the other side of the vehicle body to be temporarily stored, and are discharged to the outside of the vehicle body 1 by an auger (auger) 6.

Operations related to the raising and lowering of the harvesting unit 3 and the running of the vehicle body are performed by various operation levers located around a vehicle body operation unit 7 located in front of the other side of the vehicle body 1, and an engine 10 is disposed in the vehicle body operation unit 7, that is, in a vacant space between the lower side of the driver's seat and the grain tank 9, and the engine 10 generates power necessary for substantially running the vehicle body and driving various devices constituting the combine harvester.

The vehicle body operation portion 7 may be configured to be exposed to the outside, or may be configured to be protected by a cabin (cabin) as shown in the drawing, and an engine 10 (hereinafter referred to as "engine") is mounted in the engine compartment between the grain tank 9 and the vehicle body operation portion 7 in a lateral direction so that an output shaft faces the lateral width direction of the vehicle body, and a dust cover assembly 11 openably and closably attached between the vehicle body operation portion 7 and the grain tank 9 covers the engine compartment on a side surface.

The dust cover assembly 11 may be configured by modularizing a rotary screen for filtering foreign matter introduced together with outside air, circulating water for cooling the engine, various hydraulic device driving oils, cooling units (an intercooler, an oil cooler, a radiator) for cooling intake air, and the like, and a cooling fan (not shown in the drawing) of the engine 10 may be installed so as to be positioned between the engine 10 and the dust cover assembly 11.

As shown in fig. 4, the threshing/sifting apparatus 8 includes a threshing section including a threshing cylinder 50 for threshing and a collecting net 54 disposed below the threshing cylinder 50. Spike teeth 52 to which grains of ears of crops are raked are attached in a predetermined arrangement on the outer peripheral surface of the threshing cylinder 50, and a collecting net 54 is disposed so as to surround the lower region of the threshing cylinder at a predetermined distance from the threshing cylinder.

The threshing cylinder 50 is rotated by the power of the engine 10 diverged by the operation transmission system, crops carried to the threshing section 5 are threshed by an impact action caused by the rotation of the threshing cylinder 50, a threshing action of spike teeth, a friction action between the threshing cylinder 50 and the collecting net 54, and the like, and grains threshed by the threshing process pass through the collecting net 54 and fall down to be supplied to the screening section below.

The screening portion includes: a shaking and screening body 80 for shaking and screening the grains threshed by the threshing unit; a screening wind generator 85 that blows wind for weight screening. The shaking screen body 80 is shaken back and forth and left and right in a manner similar to a dustpan (a tool used when filtering flat grains or dust), and the screening wind generator 85 supplies wind required for screening to the shaking screen body 80.

In order to perform more precise screening in a plurality of stages, the shaking screen body 80 is composed of a feed tray (feed pan)82, a chaff screen (chaff sieve)83 continuing to the rear of the feed tray, and a screen box 81 surrounding them. The feeding tray 82 has a structure in which wedge-shaped concave-convex pieces inclined with respect to the grain advancing direction are formed at predetermined intervals, and the chaff screen 83 has a plurality of chaff pins (no reference numeral).

Among the grains passing through the chaff screen 83, grains having a relatively high specific gravity fall to the first transfer screw 87 side behind the screening wind generator 85 and are carried to the inside of the other side of the vehicle body of the grain tank 9, and among the grains passing through the chaff screen 83, grains and straws having a relatively low specific gravity fly to the second transfer screw 89 side due to the influence of wind caused by the screening wind generator 85.

The objects to be screened (such as grains and straws) flown to the second transfer screw 89 are fed to the feeding tray 82 again by the second transfer screw 89, and straws or the like such as chaffs or chips filtered in the weight screening process are sucked into the dust exhaust fan 86 disposed behind the threshing part 5 and then discharged to the outside of the vehicle body through the discharge port formed behind the vehicle body.

On the other hand, when the power of the engine 10 is supplied as the running power to a pair of left and right crawler type traveling devices which can be individually driven through a running power transmission system of a transmission case formed by a path different from the work transmission system, the individual power of a steering transmission device installed in the transmission case is interrupted, and thus various vehicle body steering such as differential steering or trim steering (refer to the background art described above) can be realized.

Referring now to fig. 5, an examination is made of a steering transmission of a work vehicle according to an embodiment of the present invention.

Fig. 5 is a sectional view of an in-transmission steering transmission device for intermittently transmitting power between a pair of right and left crawler type traveling devices and an engine in the middle to steer the vehicle in various ways.

The steering transmission device 30 is operated by operation of a steering mechanism (a steering lever, not shown) attached to the vehicle body operation unit 7 (see fig. 2). More specifically, a hydraulic mechanism (a plunger type hydraulic cylinder having a hydraulic control valve and a pair of left and right plungers, not shown) generates different power depending on the operation position of the steering mechanism, and controls power transmission between the engine and the traveling

devices

20L and 20R in accordance with the operation of the pair of left and right

clutch operation arms

31L and 31R in conjunction with the operation of the hydraulic mechanism.

The steering transmission device 30 is configured to be able to interrupt the transmission of engine power to the pair of left and right traveling

devices

20L and 20R in the middle, to provide a speed difference between the two traveling devices, or to interrupt the transmission of power to only one of the traveling

devices

20L and 20R. Therefore, the driver can operate the steering mechanism to steer the vehicle body in various forms such as differential steering or trim steering depending on the field situation.

The steering transmission device 30 includes a pair of left and right wet

multi-plate clutches

34L, 34R symmetrically mounted on one input shaft 32 that rotates by the engine power so as to interrupt the transmission of power to each of the pair of left and right traveling

devices

20L, 20R. The input shaft 32 is rotatably mounted in the transmission MC via a pair of right and left bearings B, and receives engine power transmitted through a central input gear 33 to perform rotational motion.

The wet

multi-plate clutches

34L and 34R are provided in a pair on the left and right sides with the input gear 33 as the center. The

output shafts

340L, 340R of the pair of left and right wet

multi-plate clutches

34L, 34R are disposed concentrically outside the input shaft 32 on both left and right sides of the input gear 33 so as to be relatively rotatable, and are mounted so as to be relatively movable (linearly movable) along the input shaft 32 in conjunction with the movement of the

clutch operating arms

31L, 31R.

A clutch gear 343 is formed on each of the pair of left and

right output shafts

340L, 340R, and the clutch gear 343 constantly engages with each of the pair of left and right drive transmission gears 39L, 39R connected to the pair of left and right

crawler traveling devices

20L, 20R, respectively, and when the

output shafts

340L, 340R move along the input shaft 32 in conjunction with the movement of the

clutch operation arms

31L, 31R operated by the steering mechanism, the output shafts can individually engage with the input gear 33 on both sides of the input gear 33.

For example, if the output shaft 340L of the wet multi-plate clutch 34L on the left side in the drawing of the two wet

multi-plate clutches

34L, 34R is slid in a direction to release the gear engagement with the input gear 33 by the left steering operation of the steering mechanism, the input gear 33 is released from the gear engagement with the clutch gear 343 of the output shaft 340L on the left side, and a speed difference is generated between the left running gear 20L and the right running gear 20R, thereby realizing the differential steering or the trim steering.

The differential steering and the trim steering are determined by the clutch contact state of the wet multiple disc clutch on the vehicle body steering direction side. For example, when the vehicle body is turning left, if the left wet multiple disc clutch 34L is in the half clutch state, the differential steering with a large steering radius is performed, and if the clutch is in the fully engaged clutch state, the trim steering with a relatively small radius than the differential steering is performed.

In the left-hand differential steering, the clutch gear 343 of the output shaft 340L of the left wet multiple disc clutch 34L is disengaged from the input gear 33, and the engine power is cut off, but the rotation of the

left traveling devices

20L and 20R is not completely restricted because of the half clutch state. Therefore, a speed difference is generated between the right traveling device 20R receiving the engine power and the left traveling device 20L moving by the vehicle traveling inertia, and the vehicle body is steered with a large radius.

In contrast, in the left-hand trim steering, the clutch gear 343 of the output shaft 340L of the left wet multiple disc clutch 34L falls from the input gear 33, the engine power is also cut off, and the clutch is in the fully engaged state, so that the steering of the left traveling device 20L is also completely suppressed. In this state, steering is performed only by the right running gears 20L, 20R receiving the engine power, and thus steering is performed with a relatively smaller radius than the differential steering.

The wet multiplate clutch that plays an important role in the differential steering and the trim steering will be described below with reference to fig. 6.

Fig. 6 is an enlarged view of the main portion of the wet multiplate clutch shown in fig. 5, showing the wet multiplate clutch on the left side in the drawing in the steering transmission of fig. 5. Of course, the wet multiplate clutch located on the opposite side (right side in the drawing in fig. 5) is also configured in the same manner. Therefore, only the left wet multiple disk clutch will be described as an example, with the description of the same configuration omitted.

Referring to fig. 6, a wet multi-plate clutch 34L of a work vehicle according to an embodiment of the present invention includes a hollow output shaft 340L having a clutch hub 341 and a clutch housing 342, which are integrally provided, as a clutch that is mounted to a transmission MC of a work vehicle having a pair of left and right

crawler traveling devices

20L and 20R that can be individually driven and that interrupts power transmission between the pair of left and right

crawler traveling devices

20L and 20R and an engine.

The output shaft 340L is concentrically disposed outside the input shaft 32 that rotates by engine power in a relatively rotatable manner. Further, it is equipped to move linearly along the input shaft 32 by the operation of the clutch operating arm 31L. For this purpose, one side of the clutch operating arm (clutch fork) 31L is rotatably connected to the middle of the output shaft 340L as a fulcrum, and the other side of the clutch operating arm 31L is interlockingly connected to the plunger of the plunger type hydraulic cylinder of the hydraulic mechanism.

The clutch housing 342 is fixed to a brake cover BC of the transmission MC. More specifically, the friction element 344 is inserted between the clutch hub 341 and the clutch housing 342, and the friction element 344 allows or restricts/inhibits relative rotation of the clutch hub 341 with respect to the clutch housing 342, which is a fixed body, and is attached to the brake cover BC so as to surround the clutch hub 341 formed at the distal end of the output shaft 340L with a gap.

The friction element 344 includes a plurality of pairs of first and second friction plates 344-1 and 344-2 alternately arranged between the clutch hub 341 and the clutch housing 342. The first friction plates 344-1 are spline-coupled to the outer circumference of the clutch hub 341 so as to be slidable at predetermined intervals, and the second friction plates 344-2 are spline-coupled to the inner circumference of the clutch housing 342 so as to be positioned one by one between the first friction plates 344-1.

Among the plurality of first friction plates 344-1, a pressure plate 346 that applies pressure to the friction element 344 when the clutch is engaged is attached to an adjacent side portion of the outermost first friction plate 344-1 that is farthest from the brake cover BC. The pressure plate 346 is spline-coupled to the inner periphery of the clutch housing 342 so as to be slidable, and receives a force from a pushing member 348 described later when the output shaft 340L linearly moves with respect to the input shaft 32, thereby pressing the friction element 344.

The pressure plate 346 is urged by the urging member 348 in a direction of contacting the outermost first friction plate 344-1 when the clutch is in an off (disengaged) state, a state of being spaced apart from the outermost first friction plate 344-1 by a predetermined distance, and a clutch engaged (a state in which the first friction plate 344-1 and the second friction plate 344-2 are completely contacted and integrated) or a half clutch (a state in which the first friction plate 344-1 and the second friction plate 344-2 are arranged without a gap and can slip with each other) is switched.

The urging member 348 interposes the pressure plate 346 therebetween, and is mounted on the outer periphery of the clutch hub 341 opposite to the friction element 344. The urging member 348 is moved together with the output shaft 340L to press the pressure plate 346 when the output shaft 340L is moved to the clutch engaged or half clutch operation position by the operation of the clutch operation arm 31L, or conversely, is moved linearly in a direction away from the pressure plate 346 when the clutch is disengaged.

Between the urging member 348 and the pressure plate 346, a compression elastically deformable annular disc spring 347 is mounted. The disc spring 347 has a function of uniformly dispersing the pressing force caused by the urging member 348 to the pressure plate 346 without being biased to a certain side even if the output shaft 340L linearly moving on the input shaft 32 is slightly inclined with respect to the input shaft 32 at the time of clutch contact due to machining errors or wear between parts constituting the clutch.

That is, the disc spring 347 increases the contact area with the pressure plate 346 and uniformly transmits the force to the friction element 344 during the clutch operation, so that the contact between the friction element 344 and the urging member 348 can be maintained well without being biased to one side even in the half clutch state. As a result, in the half clutch state, the friction elements 344 are prevented from being in contact with each other, and thus, the occurrence of abnormal noise can be reliably prevented.

The annular disc spring 347 may have a configuration in which an inner edge portion having a relatively small diameter is engaged with the urging member 348 to move together with the urging member 348, and an outer edge portion having a relatively large diameter is projected toward the pressure plate 346. Preferably, at the outer periphery of the urging member 348 on the side opposite to the pressure plate 346, an overlapping step a may be formed, over which the inner edge portion of the disc spring 347 overlaps.

If the disc spring 347 is constituted such that the inner edge portion having a relatively small diameter is lapped over the urging member 348 and the outer edge portion having a relatively large diameter is directed toward the pressure plate 346, the disc spring 347 is elastically compressed and deformed in the direction of diametrical expansion from the instant when the outer edge portion side contacts the pressure plate 346 in accordance with the clutch operation, so that the force pressing the friction elements 344 by the pressure plate 346 can be dispersed in a more uniform distribution in the circumferential direction.

As a result, if the disc spring 347 is constituted such that the inner edge portion having a relatively small diameter is lapped over the urging member 348 and the outer edge portion having a relatively large diameter is faced toward the pressure plate 346, it is possible to more surely prevent the biased contact and hence the occurrence of noise.

Reference numeral 349 denotes a snap ring that functions as a stopper. Specifically, the snap ring 349 is used to prevent the disc spring 347 from being disengaged from the clutch housing 342, and when the clutch is disengaged, movement of the push member 348 and the output shaft 340L is restricted to a predetermined distance, and a groove (omitted mark) is formed at a predetermined depth in an inner peripheral surface of the opening side of the clutch housing 342, and the snap ring 349 may be attached to the groove in a structure in which a part thereof is inserted.

On the other hand, another reference numeral 36 denotes an elastic member interposed between the input shaft 32 and the clutch hub 341 and providing a restoring force to the

output shafts

340L, 340R in a clutch disengagement direction. Wherein the elastic member 36 may preferably be a coiled compression spring.

Following to with the help of the utility model discloses the working vehicle turns to transmission and the automobile body that realizes turns to (the differential turns to and cut edge turns to), with the utility model discloses an operation links up mutually and examines.

Fig. 5 shows the left and right wet

multi-plate clutches

34L, 34R in a clutch disengaged state, and in the clutch disengaged state shown in fig. 5, the clutch gear 343 provided in the left and

right output shafts

340L, 340R meshes with the input gear 33 that rotates using engine power, and also meshes with the left and right pair of drive transmission gears 39L, 39R connected to the left and right crawler-

type traveling devices

20L, 20R, respectively.

Therefore, in the clutch disengaged state shown in fig. 5, if the engine power is input to the input gear 33, it is transmitted to the clutch gear 343 engaged with the pair of left and

right output shafts

340L and 340R of the input gear 33, and is transmitted to the pair of left and right drive transmission gears 39L and 39R through the clutch gear 343. As a result, the pair of left and right

crawler travel units

20L and 20R move at the same speed, and the vehicle body travels straight.

Fig. 7 and 8 are diagrams illustrating the operation state of the present invention when the vehicle body is turned, and are diagrams exemplarily illustrating the operation state of the present invention when the vehicle body is left-turned. The right steering operation of the vehicle body is performed in the same principle as the clutch engaged/disengaged state of the pair of left and right wet multi-plate clutches in the left steering operation described below. Therefore, a repetitive description of the same operation principle will be omitted.

Referring to fig. 7 and 8, if the steering mechanism attached to the vehicle body operating unit is operated to tilt to the left steering operation side, the output shaft 340L of the left wet multi-plate clutch 34L is slid in a direction (see arrow) away from the input gear 33 by the left operating arm 31L in conjunction with the operation of the hydraulic mechanism (the plunger-type hydraulic cylinder having a hydraulic control valve and a pair of left and right plungers), and therefore the gears between the clutch gear 343 of the corresponding output shaft 340L and the input gear 33 are disengaged.

As the clutch gear 343 of the output shaft 340L of the left wet multiple disc clutch 34L is separated from the input gear 33, the engine power is cut off, and as the output shaft 340L moves in the arrow direction, the urging member 348 also moves in the same direction, and presses the pressure plate 346.

At this time, the disc spring 347 installed between the urging member 348 and the pressure plate 346 functions so that the urging force caused by the urging member 348 is uniformly dispersed to be input to the pressure plate 346.

That is, the disc spring 347 increases the contact area with the pressure plate 346 and uniformly transmits the force to the friction element 344 during the clutch operation, so that the contact between the friction element 344 and the pushing member 348 is not well biased to one side even in the half clutch state in which the clutch is not completely connected, and thus the abnormal noise is not generated.

In the half clutch state (fig. 7) in which the clutch is not fully engaged, since the relative rotation between the friction plates 344-1 and 344-2 constituting the friction element 344 is allowed to some extent (slipping state), a speed difference is generated between the right running gear 20R (see fig. 2) normally driven by the engine power and the left running gear 20L (see fig. 1) moving due to the vehicle body running inertia, and as a result, the vehicle body performs a left-hand steering (differential steering) maneuver with a large radius.

In the half clutch state, if the output shaft 340L moves in a direction in which the pushing member 348 further presses the friction element 344 (fig. 8), the clutch engaged state is established, steering of the left side running gear 20L is completely suppressed, and steering is performed only by the right side running gear 20R receiving the engine power, so that the vehicle body performs left steering (trim steering) with a relatively small radius as compared to the differential steering described above.

In the wet-type multiplate clutch for a working vehicle and the steering transmission device for a working vehicle according to the embodiments of the present invention, the annular disc spring that can be elastically deformed by compression is attached between the urging member that linearly moves together with the output shaft along the input shaft and the pressure plate that presses the friction element.

Therefore, due to machining errors between the components constituting the clutch, even if the output shaft linearly moving on the input shaft as a concentric shaft is slightly inclined with respect to the input shaft when the clutch contact is attempted, the force of the urging member pressing the pressure plate can be uniformly input to the pressure plate without being biased to one side.

Therefore, even in the half-clutch state, the contact between the friction element and the movable element (pushing member) pressing the friction element can be kept good without being biased to one side, and as a result, the problem of the conventional abnormal noise caused by the biased contact between the friction element and the movable element in the half-clutch state can be solved.

In the above description, the present invention has been described only with reference to specific embodiments thereof. However, the present invention should not be construed as being limited to the particular forms set forth in the specification, but rather should be construed to include all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.

Claims

1. A wet-type multiplate clutch for a working vehicle, which is mounted to a transmission (MC) of the working vehicle having a pair of left and right crawler traveling devices (20L, 20R) that are individually drivable, and which controls power transmission between the pair of left and right crawler traveling devices (20L, 20R) and an engine at an intermediate position, the wet-type multiplate clutch for a working vehicle being characterized by comprising:

an output shaft (340L, 340R) of a hollow structure integrally having a clutch hub (341);

a clutch housing (342) attached to a Brake Cover (BC) of the transmission (MC) and surrounding the clutch hub (341) at the tip of the output shafts (340L, 340R);

a friction element (344) comprising a plurality of pairs of first friction plates (344-1) and second friction plates (344-2) alternately arranged between the clutch hub (341) and the clutch housing (342);

a pressure plate (346) that is spline-coupled to the inner periphery of the clutch housing (342) so as to be slidable, and that presses or releases the friction element (344) in accordance with the linear motion of the output shafts (340L, 340R) relative to the input shaft (32); and

an urging member (348) attached to the outer periphery of the clutch hub (341) and linearly moving together with the output shafts (340L, 340R) in a direction in which the urging member presses the pressure plate (346) or separates from the pressure plate (346);

an annular disc spring (347) which is elastically deformable in compression is mounted between the urging member (348) and the pressure plate (346).

2. The work vehicle wet multi-plate clutch according to claim 1,

a snap ring (349) is installed in the groove of the opening side of the clutch housing (342), and the disc spring (347) is prevented from being disengaged from the clutch housing (342) by means of the snap ring (349).

3. The work vehicle wet multi-plate clutch according to claim 1,

the annular disc spring (347) has a relatively small diameter inner edge portion overlapping the urging member (348) and moving together with the urging member (348), and a relatively large diameter outer edge portion projecting toward the pressure plate (346).

4. The work vehicle wet multi-plate clutch according to claim 3,

an overlapping step (A) for overlapping an inner edge portion of the disc spring (347) is formed on the outer periphery of the urging member (348) on the side opposite to the pressure plate (346).

5. The work vehicle wet multi-plate clutch according to claim 1,

the output shafts (340L, 340R) are concentrically disposed outside an input shaft (32) that rotates by engine power so as to be relatively rotatable, and are provided so as to be linearly movable along the input shaft (32) in accordance with the operation of clutch operation arms (31L, 31R).

6. The work vehicle wet multi-plate clutch according to claim 5,

an elastic member (36) is inserted between the input shaft (32) and the clutch hub (341), and the elastic member (36) provides a restoring force to the output shafts (340L, 340R) in a direction in which clutch engagement is released.

7. A work vehicle steering transmission device, which is provided with a pair of left and right crawler-type traveling devices (20L, 20R) that are individually drivable based on an operation of a steering mechanism, is characterized by comprising:

an input shaft (32) rotatably attached to a transmission (MC) and rotated by receiving engine power transmitted through an input gear (33);

the wet-type multiplate clutch (34L, 34R) as defined in any one of claims 1 to 6, which is provided in a pair on the left and right sides with the input gear (33) as a center, so that power transmission between the pair of left and right crawler-type traveling devices (20L, 20R) and the engine is interrupted in the middle;

output shafts (340L, 340R) of a pair of left and right wet-type multi-plate clutches (34L, 34R) are disposed concentrically outside an input shaft (32) on both left and right sides of the input gear (33) so as to be relatively rotatable, and are relatively moved along the input shaft (32) by operation of clutch operation arms (31L, 31R), and

a clutch gear (343) is formed on each of the output shafts (340L, 340R), and the clutch gear (343) is constantly engaged with a pair of left and right drive transmission gears (39L, 39R) connected to the pair of left and right crawler travel units (20L, 20R), respectively, and is capable of being individually engaged with the input gear (33) when the output shafts (340L, 340R) are relatively moved along the input shaft (32) by operation of the steering mechanism.