JP2003014080A - Hydraulic device and power transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic device and a power transmission that can stabilize support in the axial direction of a cylinder block without causing the relative position change of a cylinder block and one wall of a case even if the case is thermally expanded. SOLUTION: A nut 40 is screwed with an input shaft 21 with a locking flange 46 to press and fix an inner ring 38b of a conical roller bearing 38, a sleeve 37, an inner ring 38b of a conical roller bearing 39, a sleeve 41 and the cylinder block 42, and to clamp a side wall member 30 from both sides by both conical roller bearings 38, 39. Since both conical roller bearings 38, 39 clamp the side wall member 30 from both sides, even when the case 26 (the side wall member 30) is extended in the direction of an axis O by thermal expansion or the like, fixing force in the direction of the axis O of the cylinder block 42 can be kept constant.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic device and a power transmission device which can be widely used in various industrial fields such as industrial machines and vehicles.

[0002]

2. Description of the Related Art Conventionally, there is a hydraulic device having the following structure. A plunger is arranged in a cylinder block of this hydraulic device so as to project in the axial direction of the cylinder block, and the cylinder block is inserted into a rotary shaft. The cylinder block is housed in a case. Conical roller bearings are fixed to the inner wall surfaces of the case that face each other, and both ends of the rotary shaft through which the cylinder block is inserted are supported by both conical roller bearings.
Then, in order to prevent the cylinder block from moving in the axial direction with respect to the case, both sides of the cylinder block are sandwiched by both inner wall surfaces of the case via conical roller bearings.

[0003]

However, in the structure of the conventional hydraulic system, when the case thermally expands, the space between both inner wall surfaces in the axial direction expands, so that the force for pinching the cylinder block is loosened, and therefore the cylinder block is loosened. The support of the block in the axial direction was unstable.

Therefore, the present invention has been made in view of the above-described circumstances, and its object is to prevent the relative position of one wall of the case and the cylinder block from changing even when the case thermally expands, and to prevent the cylinder from moving. An object of the present invention is to provide a hydraulic device and a power transmission device that can stabilize the support of the block in the axial direction.

[0005]

In order to achieve the above object, the invention according to claim 1 is a hydraulic system in which a cylinder block having a plunger protruding in the axial direction is inserted into a rotary shaft and housed in a case. A cylinder block contact portion is provided on the rotary shaft, and the cylinder block is brought into contact with the contact portion from the side of the non-contact portion through the thrust / radial bearing inner ring so as to be opposed to the bearing outer ring and the bearing. The one wall of the case is sandwiched between the outer ring of the thrust / radial bearing and the tightening member is inserted into the rotary shaft, and the tightening member is located on the side farther than the cylinder block.
The gist is that the bearing is pressed against the inner ring of the radial bearing.

In this specification, the axial direction means the direction in which the axis of the cylinder block extends (axial direction). According to a second aspect of the present invention, in the first aspect, the first spacer is inserted between the inner rings of the pair of thrust / radial bearings,
The axial length of the first spacer is configured to be longer than the axial length of a case wall sandwiched between the pair of thrust / radial bearing outer rings, and at least one outer ring of the pair of thrust / radial bearings is provided. The gist is that the gap between the case wall and the case is adjusted.

According to a third aspect of the present invention, in contacting the cylinder block with the contact portion from the side of the non-contact portion through the thrust / radial bearing inner ring according to the first or second aspect, The gist is that the second spacer is inserted between the bearing inner ring and the cylinder block.

The invention described in claim 4 is based on claims 1 to 3.
In a power transmission device using any of the hydraulic devices up to, the hydraulic device, the plunger protrudes into both sides in the axial direction,
The plunger abuts on one side for protrusion / insertion, and the plunger on the other side protrudes / injects for output rotation to perform either relative rotation or synchronous rotation with respect to input rotation. The output shaft is rotated by the output from the prime mover, the rotary shaft is extended to the side opposite to the prime mover, and the output rotary portion is provided on the outer circumference of the extended rotary shaft. The gist is that a device for transmitting power is provided, and a device for turning on and off the rotation transmission to the rotating shaft of the prime mover is provided.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A power transmission device including a hydraulic continuously variable transmission (hereinafter referred to as continuously variable transmission 20) used for traveling of a work vehicle using the power transmission device of the present invention as a working machine. 1 to 12, an embodiment in which the hydraulic device of the present invention is embodied in a hydraulic device used in the continuously variable transmission 20 will be described.

As shown in FIGS. 1 and 3, the continuously variable transmission 2
0 is stored in the case 26 of the power unit of the working vehicle. The continuously variable transmission 20 is the first hydraulic device 10.
0, and a second hydraulic device 200 that forms a hydraulic closed circuit C (see FIGS. 9 and 10) between the first hydraulic device 100 and the first hydraulic device 100. The first hydraulic device 100 and the second hydraulic device 200 correspond to hydraulic devices.

As shown in FIG. 8, an input shaft 21 of the continuously variable transmission 20 has a clutch mechanism 30 attached to a crankshaft of an engine 22.
The yoke 23, which will be described later, is connected through 0 and is on the output side.
A gear shift device 138 (CST) is connected to. The clutch mechanism 300 is adapted to be connected / disconnected in conjunction with, for example, a stepped clutch pedal (not shown). The input shaft 21 corresponds to a rotating shaft.

The gear shift device 138 includes the first clutch 1
39 and a second clutch 140. When the driven clutch plate is connected to the drive side clutch plate connected to the yoke 23, the first clutch 139 causes the gear 141 connected to the driven clutch plate to move to the gear 14
The drive torque is transmitted to the final reduction gear transmission (not shown) via 2. Further, when the driven clutch plate is connected to the drive side clutch plate connected to the yoke 23, the second clutch 140 has a gear 143, an idler gear 144,
145 and the gear 14 meshed with the idler gear 145
The drive torque is transmitted to the final reduction gear transmission (not shown) via 2.

The gear shift device 138 includes the shift lever 14
6 (see FIG. 11), and based on the operation of this shift lever 146, the first clutch 13
9 is connected, and the second clutch 140 is connected during reverse travel.

In the present embodiment, the engine 22
Is a motor, and the clutch mechanism 300 is equivalent to “a device for turning on / off the rotation transmission to the rotary shaft of the motor”. Further, the gear shift device 138 corresponds to "a device that transmits power in the same direction as or reversely to the rotation direction of the output rotation unit".

The case 26 of the continuously variable transmission 20 has a cylindrical tubular member 27, and bolts (not shown) through bolt insertion holes 28 and 29 (see FIG. 3) so as to close openings at both ends of the tubular member 27. Pair of side wall members 3 integrally connected by
It is composed of 0 and 31.

In the input shaft 21 of the continuously variable transmission 20,
The input end side is rotatably supported by the side wall member 30 of the case 26 via a bearing 32. Also, case 2
The side wall member 31 of 6 has a yoke 23 as an output rotating portion.
Are rotatably supported via bearings 33. Then, the output end side of the input shaft 21 is positioned coaxially with the yoke 23, so that the pair of bearings 23 a are provided with respect to the yoke 23.
And is rotatably pierced and supported through the oil seal 23b. The end portion protruding from the yoke 23 at the output end is the PTO shaft.

As shown in FIG. 4, at the center of the side wall member 30, a pair of bearing accommodating holes 34 and 35 are arranged side by side on both inner and outer side surfaces so as to be coaxially arranged. A through hole 36 having a diameter smaller than that of the bearing housing holes 34, 35 is formed between the bearing housing holes 34, 35.

A sleeve 37 as a first spacer is rotatably arranged in the through hole 36, and conical roller bearings are provided in the bearing receiving holes 34 and 35 so as to face each other with the through hole 36 interposed therebetween. 38 and 39 are fitted and fixed. The conical roller bearings 38 and 39 correspond to thrust / radial bearings. The input shaft 21 is a double conical roller bearing 38, 3
It is supported via 9. Further, the opening of the bearing accommodating hole 34 is covered with a cover 15 bolted to the side wall member 30 with a bolt (not shown). As shown in FIG. 4, the input shaft 21 is passed through the through hole 15 a of the cover 15 via the seal member 16.

A washer-shaped shim 50 is in contact with the output end side of the outer ring 38a of the conical roller bearing 38. The outer diameter of the shim 50 is substantially the same as the inner diameter of the bearing housing hole 34,
The inner diameter of the shim 50 is set so that the input shaft 21 can be inserted therethrough. In the present embodiment, the shim 50 adjusts the gap between the side surface of the outer ring 38a of the conical roller bearing 38 and the sleeve 37.

As shown in FIG. 4, the outer ring 38a of the conical roller bearing 38 is brought into contact with the bottom surface 34a of the step portion on the inner side of the bearing accommodating hole 34 through the shim 50, and the outer ring 38a is formed in the bearing accommodating hole 34. It is fitted to the inner peripheral surface. Also, conical roller bearing 3
The outer ring 39a of 9 is the bottom surface 35 of the step portion on the inner side of the bearing housing hole 35.
The outer ring 39 a is fitted to the inner peripheral surface of the bearing housing hole 35.

The length of the sleeve 37 in the direction of the axis O is longer than the length between the step bottom surfaces 34a and 35a. The axis O means the axis of the cylinder block 42.

The side surfaces on the input end side and the output end side of the sleeve 37 are in contact with the inner ring 38b of the conical roller bearing 38 and the inner ring 39b of the conical roller bearing 39. The inner ring 38b corresponds to a "thrust / radial bearing inner ring on the side farther than the cylinder block". The side faces of the sleeve 37 on the input end side and the output end side are the outer ring 38 a of the conical roller bearing 38 and the outer ring 3 of the conical roller bearing 39.
9a is in a non-contact state.

In the bearing housing hole 34, a nut 40 is screwed onto the outer periphery of the input shaft 21 on the input end side. The nut 40 corresponds to a fastening member. The nut 40 is in contact with the inner ring 38b of the conical roller bearing 38 and is not in contact with the outer ring 38a.

By screwing the nut 40, the conical roller bearing 3
8 presses the inner ring 39b of the conical roller bearing 39 via the sleeve 37, and further the sleeve 37
Are configured to press the inner ring 39b of the conical roller bearing 39. The pressed inner ring 39b is configured to press the sleeve 41 fitted to the input shaft 21. The sleeve 41 corresponds to the second spacer.

Further, as shown in FIG. 4, the pressed sleeve 41 presses the locking flange 46 of the input shaft 21 against the cylinder block 42 integrally connected to the input shaft 21 by the spline 21a coupling. It is configured. The locking flange 46 corresponds to a cylinder block contact portion. That is, the cylinder block 42 is pressed and fixed to the input shaft 21 having the locking flange 46 through the inner ring 38b, the sleeve 37, the inner ring 39b, and the sleeve 41 by fastening the nut 40.

Further, by screwing the nut 40 onto the input shaft 21, the conical roller bearing 38 and the conical roller bearing 39 are screwed.
Sandwich the peripheral edge of the through hole 36 (the stepped portion bottom surface 34a and the stepped portion bottom surface 35a) from both sides. The side wall member 30 having the through hole 36 corresponds to "one wall of the case" and "a case wall sandwiched between a pair of thrust / radial bearing outer rings". Then, the outer ring 38a and the step bottom surface 3
By disposing the shim 50 between the nut 4 and 4a and adjusting the thickness of the shim 50, when the nut 40 is screwed into the input shaft 21,
The preload of each of the conical roller bearing 38 and the conical roller bearing 39 is set to be optimum. Incidentally, as the thickness of the shim 50 increases, the preload applied to the bearings 38, 39 increases, and as the thickness of the shim 50 decreases, the preload applied to the bearings 38, 39 decreases.

Conical roller bearings 38, 39 and sleeve 37
The bearing portion 32 is configured by the above. (First Hydraulic System 100) The first hydraulic system 100 includes an input shaft 21, a cylinder block 42, a plunger 43, and a cradle 45 including a swash plate surface 44 that abuts against the plunger 43. The input shaft 21 passes through the cradle 45. The swash plate surface 44 corresponds to the plunger contact portion.

As shown in FIG. 1, the cradle 45 is supported so as to be tiltable with respect to the case 26 about a trunnion axis TR which is orthogonal to the axis O. That is,
The cradle 45 has a virtual plane including the swash plate surface 44,
The position perpendicular to the axis O is the upright position. The cradle 45 is inclined at a predetermined angle in the counterclockwise direction in FIG. 1 based on the upright position (first position).
And a position (second position) tilted clockwise by a predetermined angle with respect to the upright position.

In the present embodiment, the clockwise direction is positive and the counterclockwise direction is negative in FIG. 1 with reference to when the swash plate surface 44 is in the upright position. In the present embodiment, when the output speed Nout = Nin in FIG.
When out> Nin, tilts to the negative side, and when Nout <Nin,
Tilt to the positive side. The output rotation speed is the rotation speed of the yoke 23.

The swash plate surface 44 shown in FIG. 1 shows a state in which the cradle 45 is tilted at the maximum negative tilt angle position when it is in the first position. Also, cradle 45
Is located at the second position, the swash plate surface 44 is referred to as a positive tilt angle position.

The cylinder block 42 has a substantially cylindrical combination shape, and both end circumferential surfaces located in the axial center O direction (axial direction) have a diameter smaller than that of the central portion. Cylinder block 42
2, a plurality of plunger holes 47 are annularly arranged around the center of rotation (axis O) of the central portion and extend parallel to the axis O. As shown in FIG. 1, the plunger hole 47 is formed in the cylinder block 42.
An opening is formed on the cradle 45 side on the step surface of the central part of the. Each plunger hole 47 has a plunger 4
3 is slidably arranged. A steel ball 48 is rotatably fitted to the tip of the plunger 43, and the plunger 43 has a steel ball 48 and a shoe 49 to which the steel ball 48 is attached.
Is in contact with the swash plate surface 44 through. The swash plate surface 44 in the inclined state causes the plunger 43 to reciprocate in accordance with the rotation of the cylinder block 42, thereby giving the action of the suction and discharge strokes. Note that FIG. 1 is a cross-sectional view taken along the line CC of FIG.

(Second hydraulic device 200) Second hydraulic device 20
Reference numeral 0 includes a plurality of plungers 58 slidably arranged on the cylinder block 42, and a cylindrical yoke 23 having a rotating inclined surface 51 that abuts on the plunger 58.

As shown in FIGS. 1 and 3, a bearing accommodating hole 52 and a through hole 53 having a diameter smaller than that of the bearing accommodating hole 52 are formed in the side wall member 31 so as to be coaxial with each other. The conical roller bearing 5 is placed in the bearing housing hole 52.
4 is fitted. A ball bearing 55 is fixed to the inner peripheral surface of the output end of the tubular member 27. The yoke 23 includes a large diameter portion and a small diameter portion, and the large diameter portion is fitted to the ball bearing 55 and the small diameter portion is fitted to the conical roller bearing 54 so as to be rotatably supported. Further, the small diameter portion of the yoke 23 is projected to the outside through a seal member 56 fixed in the through hole 53.

The rotary slope 51 is formed on the end surface of the yoke 23 on the cylinder block 42 side, and a virtual plane including the rotary slope 51 is inclined at a constant angle with respect to the axis O.

At the center of the cylinder block 42,
As shown in FIG. 2, the same number of plunger holes 57 as the plunger holes 47 are annularly arranged around the rotation center and extend parallel to the axis O. The pitch circle of the plunger hole 57 is concentric and has the same diameter as the pitch circle of the plunger hole 47. Further, as shown in FIG. 2, the plunger holes 57 are arranged so as to be located between the plunger holes 47 adjacent to each other in the circumferential direction of the cylinder block 42 so as to be offset from the plunger holes 47 by 1/2 pitch. There is.

The plunger hole 57 is formed in the cylinder block 42.
An opening is formed on the side of the yoke 23 on the step surface of the central portion of the. A plunger 58 is slidably arranged in each plunger hole 57, and a steel ball 59 is rotatably fitted to the tip of the plunger 58. Plunger 58 is steel ball 59
And the shoe 60 to which the steel ball 59 is attached is abutted on the rotating slope 51. The plunger 58 reciprocates according to the relative rotation between the rotary slope 51 and the cylinder block 42, and the suction and discharge strokes are repeated. In this embodiment,
The maximum stroke volume VPmax of the first hydraulic apparatus 100 is set to be the same as the maximum stroke volume VMmax of the second hydraulic apparatus 200. In addition, in the present embodiment, the stroke volume is one per one rotation of the hydraulic devices 100 and 200. In the case of the first hydraulic device 100, it means the stroke volume per one rotation on the input side (input shaft 21), and in the case of the second hydraulic device 200, the stroke volume when the output side (yoke 23) makes one revolution. Become.

(Hydraulic closed circuit C) The first hydraulic device 100
The hydraulic closed circuit C formed between the second hydraulic device 200 and the second hydraulic device 200 will be described.

On the inner peripheral surface of the cylinder block 42, an annular first oil chamber 61 and a second oil chamber 62 are arranged side by side in the axial direction of the cylinder block 42. For convenience of explanation, the first oil chamber 61 is referred to as the oil chamber A and the second oil chamber 6 is referred to.
2 may be referred to as an oil chamber B. The cylinder block 42 is provided with the same number of first valve holes 63 that communicate the first oil chamber 61 and the second oil chamber 62 as the plunger holes 47 along the axial direction of the cylinder block 42. Further, the cylinder block 42 has a plurality of second valve holes 64, which communicate with both the first oil chamber 61 and the second oil chamber 62, extending along the axial direction of the cylinder block 42 in the same number as the plunger holes 57. There is.

The pitch circle of the first valve hole 63 is concentric and has the same diameter as the pitch circle of the second valve hole 64. Further, the diameter of the pitch circle is smaller than the pitch circle of the plunger holes 47, 57 so as to be located inward of the plunger holes 47, 57. Further, each first valve hole 63 is located between the adjacent second valve holes 64, and in the circumferential direction of the cylinder block 42 as shown in FIG. They are arranged in a staggered manner. In addition, the centers of the first valve hole 63 and the plunger hole 47, and the second valve hole 64.
The centers of the plunger holes 57 are arranged so as to be located on a straight line extending radially from the axis O, as shown in FIG.

As shown in FIG. 1, the oil passage 65 connects the bottom portion of the plunger hole 47 and the portion of the first valve hole 63 between the first oil chamber 61 and the second oil chamber 62. Has been formed. A portion between the bottom of the plunger hole 47 and the first oil chamber 61 and the second oil chamber 62 of the first valve hole 63 is a predetermined distance in the length direction of the cylinder block 42 (direction in which the axis O extends). Are arranged to have. Therefore,
As shown in FIGS. 1 and 6, the oil passage 65 is inclined from the outer peripheral side of the cylinder block 42 toward the inside.

Each first valve hole 63 has a first oil chamber 61 and a second oil chamber 61.
A port U of the oil passage 65 communicating with the corresponding plunger hole 47 is formed between the oil chamber 62 and the oil chamber 62. Each first
A spool-type first switching valve 66 is slidably arranged in the valve hole 63. The first switching valve 66 corresponds to a distribution valve. A cylindrical holder 68 is fixed to the outer peripheral surface of the outer ring 39a of the conical roller bearing 39. On the inner peripheral surface of the holder 68, the central portion in the axial direction is reduced in diameter, and a retainer 70 is rotatably supported by the reduced diameter portion via a ball bearing 69. As shown in FIG. 6A, the retainer 70 is composed of a cylindrical tubular portion 71 and a flange 72 that is formed to project from the end of the tubular portion 71 on the cylinder block 42 side. As shown in FIG. 3, the retainer 70 is arranged so that its axis is oblique to the axis O by the ball bearing 69, and in this state, the input shaft 21 is rotatably penetrated. There is. Due to this oblique intersection, the virtual plane including the surface of the flange 72 that faces the cylinder block 42 (hereinafter referred to as the flange surface) obliquely intersects the axis O.

As shown in FIG. 6A, on the flange 72 of the retainer 70, locking grooves 73 are formed by cutting from the outer circumference toward the shaft center at equal angles around the shaft center. As shown in FIG. 6B, a constricted portion 66b provided on the first switching valve 66 is engaged with the locking groove 73.
The constricted portion 66b has a smaller diameter than the adjacent large diameter portion 66c.

The first switching valve 66 is engaged with a retainer 70 having a flange surface that obliquely intersects with the axis O so that the first switching valve 66 shown in FIG.
A displacement as shown in is realized. The flange 72 of the retainer 70 has the first switching valve 66 centered at the port closed position n0 and the port U (oil passage 65) via the first valve hole 63.
And a second opening 62 for communicating the second oil chamber 62 and a second opening n2 for communicating the port U (oil passage 65) with the first oil chamber 61 are reciprocated along the axial direction of the cylinder block 42. Let The axial direction of the cylinder block 42 corresponds to the reciprocating direction. As a result of this retainer 70, the first hydraulic device 100 has a region H as shown in FIG.
And region I are given.

Here, the region H means the port U and the second oil chamber 6
2 is an area including all sections communicating with each other, and an area I
Is an area including the entire section in which the port U and the first oil chamber 61 communicate with each other.

When the swash plate surface 44 is displaced from the upright position to the negative tilting angle position, in FIG. 12, the stroke volume VP of the first hydraulic system 100 at this time is from 0 to VMmax, and the stroke is input accordingly. In this embodiment, when the input rotation speed of the shaft 21 is Nin, the output rotation speed Nout (the rotation speed of the yoke 23) is in the range of Nin to 2Nin. The amount is set.

In FIG. 12, the vertical axis represents the stroke volume per rotation of the first hydraulic device 100 and the second hydraulic device 200, and the horizontal axis represents the output rotational speed Nout of the yoke 23 (output rotating portion). There is. In the same figure, the solid line shows the change of the stroke volume VP of the first hydraulic device 100, and the chain line shows the change of the stroke volume VM of the second hydraulic device 200.

The stroke volume of the first hydraulic system 100 means that the plunger chamber formed by the plunger 43 and the plunger hole 47 is exchanged with the first oil chamber 61 and the second oil chamber 62 while the cylinder block 42 makes one rotation. It is the amount of hydraulic oil to be used. The stroke volume of the second hydraulic device 200 means the plunger 5
8 and the plunger hole 57, the amount of hydraulic oil transferred to and from the first oil chamber 61 and the second oil chamber 62 while the yoke 23 (output rotating part) makes one rotation with respect to the cylinder block 42. That is.

Further, in the present embodiment, when the swash plate surface 44 is tilted to the negative side as shown in FIG. 3, the hydraulic oil is rotated in the range of 0 ° to 180 ° around the axis O of the cylinder block 42. Is sucked into the plunger hole 47 through the port U, and 180
The operating oil is discharged from the plunger hole 47 through the port U in the range of ° to 360 ° (0 °). Then, when the swash plate surface 44 tilts to the positive side, the hydraulic oil is discharged from the plunger hole 47 through the port U within a rotation angle range of 0 ° to 180 ° around the axis O of the cylinder block 42, 18
In the range of 0 ° to 360 ° (0 °), the hydraulic oil is sucked into the plunger hole 47 via the port U. The oil chamber to be discharged and the oil chamber to be sucked are determined by regions H and I corresponding to the rotation angle of the cylinder block 42 around the axis O.

As shown in FIGS. 1 and 3, the oil passage 75 is
The bottom of the plunger hole 57 and the first oil chamber 6 of the second valve hole 64.
The first and second oil chambers 62 are formed to communicate with each other. The bottom of the plunger hole 57 and the second valve hole 6
The portion between the first oil chamber 61 and the second oil chamber 62 is the length direction of the cylinder block 42 (the direction in which the axis O extends).
Are arranged so as to have a predetermined distance. Therefore, as shown in FIGS. 1 and 3, the oil passage 75 is inclined from the outer peripheral side of the cylinder block 42 toward the inner side.

Each of the second valve holes 64 has a first oil chamber 61 and a second oil chamber 61.
A port W of an oil passage 75 communicating with the corresponding plunger hole 57 is formed between the oil chamber 62 and the oil chamber 62. Each second
A second spool-type switching valve 76 is slidably arranged in the valve hole 64 so as to be parallel to the plunger 58. The second switching valve 76 corresponds to a distribution valve.

As shown in FIG. 5, a storage hole 78 is formed in the center of the end surface of the yoke 23 on the cylinder block 42 side. A cylindrical support member 81 into which the input shaft 21 is inserted is provided in the storage hole 78. The support member 81 is
A plurality of pins 82 are attached to the bottom of the housing hole 78 of the yoke 23.
Are integrally connected via (see FIG. 3). A retainer 83 is rotatably connected to the inner circumference of the support member 81 via a ball bearing 84.

The retainer 83 has a cylindrical portion, a flange, and a locking groove that have the same structure as the retainer 70. Therefore, the same reference numerals are assigned to those structures and the description thereof will be omitted (see FIG. 6 (a)).

As shown in FIG. 3, the retainer 83 is arranged so that its axis intersects with the axis O by a ball bearing 84. In this state, the input shaft 21 is rotatably penetrated. ing. Due to this crossing, the surface of the flange 72 that faces the cylinder block 42 (hereinafter referred to as the flange surface)
An imaginary plane including is oblique to the axis O.

The retaining groove 73 of the retainer 83 is shown in FIG.
As shown in (b), the constricted portion 76b provided on the second switching valve 76 is engaged. The constricted portion 76b has a smaller diameter than the adjacent large diameter portion 76c.

The second switching valve 76 is engaged with a retainer 83 having a flange surface obliquely intersecting with the axis O, so that the second switching valve 76 shown in FIG.
A displacement as shown in is realized. Note that, in FIG. 7, the relative position between the flange 72 of the retainer 70 and the flange 72 of the retainer 83 changes because the retainers 70 and 83 are rotatable, but for convenience of description, they are collectively shown in one diagram. Shows.

Then, with the relative rotation of the yoke 23 (output rotating portion) with the cylinder block 42, the retainer 83
Due to the flange 72 of the second hydraulic device 200, the relative rotation angle of the yoke 23 (output rotating part) about the axis O with respect to the cylinder block 42 in the range J of 0 ° to 180 °,
The region K is given in the range of 180 ° to 360 ° (0 °).

Here, the area J is the port W and the first oil chamber 6
1 is an area including all the communicating sections, and an area K
Is an area including the entire section where the port W and the second oil chamber 62 communicate with each other.

Further, in the present embodiment, when the swash plate surface 44 tilts to the negative side as shown in FIG. 1, the relative rotation angle of the yoke 23 (output rotation portion) with respect to the cylinder block 42 about the axis O is 0 °. In the range of 180 ° to 180 °, the hydraulic oil is sucked into the plunger hole 57 via the port W, and 180 ° to 360 °.
In the range of (0 °), the hydraulic oil is discharged from the plunger hole 57 via the port W. When the swash plate surface 44 tilts to the positive side, the hydraulic oil passes through the port W within a range of a relative rotation angle of 0 ° to 180 ° around the axis O of the yoke 23 (output rotation portion) with respect to the cylinder block 42. The hydraulic fluid is discharged from the plunger hole 57 and is sucked into the plunger hole 57 through the port W in the range of 180 ° to 360 ° (0 °). The oil chamber to be discharged and the oil chamber to be sucked are determined by regions J and K corresponding to the relative rotation angle of the yoke 23 (output rotation portion) with respect to the cylinder block 42 about the axis O.

The plunger hole 47 and the plunger hole 5
7, first oil chamber 61, second oil chamber 62, first valve hole 63, second
Valve hole 64, oil passage 65, oil passage 75, port U and port W
A closed hydraulic circuit C is constituted by and.

In order to charge the hydraulic closed circuit C with hydraulic oil, a shaft hole 99 is formed in the input shaft 21 along the shaft center O. The shaft hole 99 has an introduction oil passage 99a in the radial direction at a portion corresponding to the sleeve 37 (see FIG. 1). The introduction oil passage 99a includes an oil passage 37a formed in the sleeve 37 in the radial direction and the circumferential groove 3 formed on the outer peripheral surface.
It is connected to 7b. The side wall member 30 is provided with an oil passage 30a communicating with the circumferential groove 37b, and hydraulic oil is pumped into the oil passage 30a from a charge pump (not shown). Also,
In the shaft hole 99, a plug 121 is screwed into an opening on the output end side of the input shaft 21 so that the screwing amount can be adjusted.

On the other hand, in the input shaft 21, the first oil chamber 61
A charge valve 90 (check valve) that opens and closes a valve seat that can communicate with the shaft hole 99 is arranged in each of the second oil chambers 62. The valve body of the charge valve 90 opens until the hydraulic pressure in the hydraulic closed circuit C reaches the charge pressure in the shaft hole 99,
The hydraulic oil in 9 is supplied to the hydraulic closed circuit C. The charge valve 90 also prevents hydraulic oil from flowing back to the shaft hole 99.

(Operation) Now, the operation of the continuously variable transmission 20 constructed as described above with the tilting of the cradle 45 will be described. In addition, from the crankshaft of the engine 22 to the input shaft 2
For convenience of description, the input rotation speed Nin given to 1 will be described as a constant value.

(When the output speed Nout is Nin) FIG. 11
Operate the shift lever 146 shown in to operate the cradle 45.
The swash plate surface 44 is positioned at the upright position via the.

In this state, the driving force of the engine 22 causes the cylinder block 42 to move to N through the input shaft 21.
Rotate in. The gear shift device 138 (C
ST) or a gear shift device 15 shown in FIG. 13 described later.
When 0 is connected, the rotation of the gear 142 or the output shaft 155 in the direction opposite to Nin is referred to as positive rotation.

The swash plate surface 44 is in a neutral state in an upright position with respect to the axis O of the input shaft 21. The plunger 43 of the first hydraulic device 100 is not reciprocated by the swash plate surface 44, and therefore, in this state, the hydraulic oil does not circulate in the closed hydraulic circuit C. Therefore, on the side of the second hydraulic device 200, the protruding end of each plunger 58 abuts and engages with the rotating slope 51 through the shoe 60 in a state where the stroke motion is not possible.
The cylinder block 42 and the rotary slope 51 are directly connected to each other and rotate integrally. That is, this state is the input shaft 21
And the gear 142 are directly connected. The rotation in the forward direction imparted to the rotary slope 51 is transmitted to the final reduction gear via the yoke 23, the connected first clutch 139, the gear 141, and the gear 142.

When the swash plate surface 44 is located in the upright position, the stroke volume VP of the first hydraulic system 100 becomes 0 and the output speed Nout (yoke 23
The rotation speed of is the input rotation speed Nin.

(When the output speed Nout is between Nin and 2Nin) The shift lever 146 is operated to move the cradle 45.
The swash plate surface 44 is tilted to the negative side via the and to be positioned in a region between a predetermined negative tilt angle position and the upright position. The predetermined negative tilt angle position is a position until the absolute value of the stroke volume VP of the first hydraulic device 100 becomes equal to the absolute value (= VMmax) of the stroke volume VM of the second hydraulic device 200.

In this case, the driving force of the engine 22 causes the cylinder block 42 to rotate at Nin via the input shaft 21. Then, the first hydraulic device 100 sucks the working oil into the plunger hole 47 through the port U within the range of the rotation angle of 0 ° to 180 ° around the axis O of the cylinder block 42, and 1
In the range of 80 ° -360 ° (0 °), hydraulic oil is supplied to port U
Through the plunger hole 47. The oil chamber to be discharged and the oil chamber to be sucked are determined by regions H and I corresponding to the rotation angle of the cylinder block 42 around the axis O. still,
The amount of hydraulic oil discharged and sucked by the first hydraulic device 100 increases as the tilt angle of the swash plate surface 44 to the negative side increases. At this time, the second hydraulic device 200 supplies the operating oil to the port W within a range of a relative rotation angle of 0 ° to 180 ° around the axis O of the yoke 23 (output rotation portion) with respect to the cylinder block 42.
Through the plunger hole 57 through 180 ° to 360 °
The operating oil is discharged from the plunger hole 57 through the port W in the range of ° (0 °). The oil chamber for discharging and the oil chamber for sucking are provided in the cylinder block 4 of the yoke 23 (output rotating portion).
A region J corresponding to the relative rotation angle around the axis O with respect to 2,
It depends on K.

As a result, the rotation speed Nin at which the cylinder block 42 is driven via the input shaft 21 and the plunger 58
The rotational slope 51 is rotated by combining (summing) with the number of rotations in the positive direction due to the protrusion pressing action on the rotational slope 51. The rotation in the positive direction imparted to the rotation slope 51 is generated by the yoke 2
3, the first clutch 139, the gear 141, and the gear 142, which are connected to each other, are transmitted to the final reduction gear transmission as rotation in the forward direction, and the speed-up action is performed.

At this time, when the swash plate surface 44 is displaced from the upright position to the side of the predetermined negative tilt angle position, the stroke volume VP of the first hydraulic system 100 increases from 0 to VMmax in FIG. Output speed Nout is 2N from Nin
Speed up to in. In addition, the output speed Nout is 2 from Nin.
Stroke volume V of the second hydraulic device 200 when changing to Nin
M remains at VMmax. The flow and rotation of the hydraulic oil in this state are shown in FIG. 10. At this time, in the hydraulic closed circuit C, the hydraulic oil flows as shown by the arrows in the figure. The arrows attached to Nin and Nout indicate the rotation directions of the corresponding members.

(When the output speed Nout is between 0 and Nin) The shift lever 146 is operated to tilt the swash plate surface 44 to the positive side through the cradle 45 to move it from the upright position to the positive tilt angle position. Position it. Note that, of the positive tilting angle positions, the predetermined positive tilting angle position means the first hydraulic device 100.
This is the position until the absolute value of the stroke volume VP becomes equal to the absolute value of the stroke volume VM of the second hydraulic device 200.

In this case, since the swash plate surface 44 tilts in the positive direction, when the cylinder block 42 rotates via the input shaft 21 due to the driving force of the engine 22, the first hydraulic device 10
0 indicates a rotation angle of 0 ° around the axis O of the cylinder block 42.
The working oil is discharged from the plunger hole 47 through the port U in the range of 180 ° to 180 °, and the working oil is sucked into the plunger hole 47 through the port U in the range of 180 ° to 360 ° (0 °). The oil chamber to be discharged and the oil chamber to be sucked in have a region H corresponding to a rotation angle around the axis O of the cylinder block 42
It depends on I. The amount of hydraulic oil discharged and sucked by the first hydraulic device 100 increases as the tilt angle of the swash plate surface 44 toward the positive side increases. At this time, the second hydraulic device 20
0 is the cylinder block 4 of the yoke 23 (output rotating part)
The hydraulic oil is discharged from the plunger hole 57 through the port W in the range of a relative rotation angle of 0 ° to 180 ° around the axis O with respect to 2, and the hydraulic oil is discharged in the range of 180 ° to 360 ° (0 °). Suction into the plunger hole 57 through the port W. The oil chamber to be discharged and the oil chamber to be sucked are determined by regions J and K corresponding to the relative rotation angle of the yoke 23 (output rotation portion) with respect to the cylinder block 42 about the axis O.

As a result, the rotary slope 51 of the plunger 58 is
The output pressing speed Nout is N
rotation between "in and 2Nin". Therefore, the composite (sum) of the rotation speed in the reverse direction and the rotation speed in the positive direction of the cylinder block 42 is transferred to the final reduction gear transmission via the yoke 23, the connected first clutch 139, the gear 141, and the gear 142. Transmitted. Since the sum of the rotational speeds at this time becomes the rotational speed in the forward direction reduced by the rotational speed in the reverse direction, the output rotational speed Nout becomes smaller than that in the case where the output rotational speed Nout is Nin.

In this embodiment, at this time, when the swash plate surface 44 is displaced from the upright position to the positive maximum tilt angle position side,
In FIG. 12, the stroke volume VP of the first hydraulic device 100 is 0.
To -VMmax (the "-" is from the port U to the second oil chamber 62)
It means that the ink is discharged to. ) Side, and the output speed Nout decelerates accordingly from Nin to 0.

The output speed Nout at this time is Nin
The stroke volume VM per rotation of the second hydraulic device 200 when changing from 0 to 0 is -VMmax. (The "-" means the case of being sucked into the port W from the second oil chamber 62.) FIG. 9 is a schematic view of the state at this time. First
The oil chamber 61 (oil chamber A) side is at a higher pressure side than the second oil chamber 62 (oil chamber B) side, and in the hydraulic closed circuit C, the flow of hydraulic oil as shown by the arrow in the figure Has become. Also, N
The arrows attached to in and Nout indicate the rotation directions of the corresponding members.

(When the output speed Nout is 0) The yoke 23 is stopped by disconnecting the input rotation from the engine 22 by the clutch mechanism 300.

(When the output speed Nout is less than 0) When the shift lever 146 is shifted to the reverse drive side while the clutch mechanism 300 is disengaged, the first clutch of the gear shift device 138 responds to the operation of the shift lever 146. 139
Is disengaged and the second clutch 140 is engaged. At this time, the rotation from the engine 22 side is not transmitted to the continuously variable transmission 20, so that the pressing action of the plunger 58 on the rotating slope 51 is lost, and the yoke 23 becomes free from the second hydraulic device 200. Therefore, the second yoke 23
It is possible to easily connect the clutch 140, that is, to switch the vehicle in reverse. Then, after shifting the shift lever 146 to the reverse drive side, the clutch mechanism 300 is brought into the connected state again. When returning to the forward side, the foot clutch is depressed for the same reason, and the clutch mechanism 300 is disengaged.

(When the output speed Nout is between 0 and -Nin) After the reverse connection by the second clutch 140 is performed, as shown in FIG. 9, the output speed Nout and the first hydraulic system 100 are changed. The change state of the stroke volume is the same as the case of forward movement (normal rotation), and is the same as the description (when the output rotation speed Nout is between 0 and Nin), and thus the description thereof is omitted. FIG. 9 shows the flow and rotation direction of the hydraulic oil. In this case, the rotation applied to the rotation slope 51 is the yoke 23 and the second clutch 1.
40, the gear 143, the idler gears 144, 145, and the gear 142, and is transmitted to the final reduction gear transmission.

(When the output speed Nout is between Nin and -2Nin) Also in this case, the action of the first hydraulic device 100 and the second hydraulic device 200 is (when the output speed Nout is between Nin and 2Nin). Since it is the same as, the description will be omitted. Figure 10
Indicates the flow and rotation direction of the hydraulic oil. Also in this case, the rotation imparted to the rotation slope 51 is caused by the yoke 23, the second
Clutch 140, gear 143, idler gear 144, 1
It is transmitted to the final reduction gear transmission via 45 and the gear 142.

Therefore, according to the above embodiment, the following effects can be obtained. (1) In the above embodiment, the cylinder block 42 having the plungers 43 and 58 protruding in the direction of the axis O is inserted into the input shaft 21, and the cylinder block 42 is inserted into the case 2.
Stored in 6. A locking flange 46 is provided on the input shaft 21, and the cylinder block 42 is brought into contact with the locking flange 46 from the input end side via the inner ring 39b of the conical roller bearing 39 and the sleeve 41. Further, the side ring member 30 of the case 26 is sandwiched between the outer ring 39a of the conical roller bearing 39 and the outer ring 38a of the conical roller bearing 38 arranged to face the conical roller bearing 39. In addition, the nut 40 is inserted into the input shaft 21, and the nut 40 is inserted into the inner ring 38b.
It is configured to be pressed against.

Therefore, by tightening the nut 40 on the input shaft 21, the conical roller bearings 38 and 39, the sleeve 41, which are located between the nut 40 and the locking flange 46,
The cylinder block 42 is tightened and fixed, and play between the members is prevented. Further, by tightening the nut 40 onto the input shaft 21, the conical roller bearing 38 and the conical roller bearing 3
9 sandwiches the peripheral portion of the through hole 36 from both sides, and can support the input shaft 21 and the cylinder block 42 with respect to the side wall member 30.

The bearings 38 and 39 are attached to the side wall member 3
Since 0 is sandwiched, even if the side wall member 30 expands in the direction of the axis O due to thermal expansion, the bearings 38 and 39, the sleeve 4
1 and the cylinder block 42 does not rattle in the direction of the axis O. Therefore, even if the case 26 thermally expands, the relative position of the side wall member 30 of the case 26 and the cylinder block 42 does not change, and the support of the cylinder block 42 in the axis O direction can be stabilized.

(2) In the above embodiment, the sleeve 37 is provided between the outer rings 38a, 39a of the conical roller bearings 38, 39 arranged opposite to each other, and the sleeve 37 is in contact with the inner rings 38b, 39b.
The length of the sleeve 37 in the direction of the axis O is longer than the length between the step bottom surfaces 34a and 35a. Further, a shim 50 having an adjusted thickness is provided between the outer ring 38a and the stepped portion bottom surface 34a of the bearing housing hole 34. Therefore, the shim 50
Both outer rings 38a, 39a and the step bottoms 34a, 3
Since the clearance between the side wall member 30 and the side wall member 30 having 5a can be adjusted, the preload of each of the conical roller bearing 38 and the conical roller bearing 39 can be set to be optimum. Therefore, the durability time of the bearing is increased.

(3) In the above embodiment, output rotation can be obtained from both the input shaft 21 and the yoke 23 extended to the output side. Also, the rotation of the yoke 23 is caused by the cradle 4
By the tilting angle of 5 and the gear shift device 138, a wide range of driving torque can be transmitted to the final reduction gear device in the forward and reverse directions.

(4) In the above embodiment, the clutch mechanism 3
By cutting 00, the torque applied to the yoke 23 when switching the rotation of the yoke 23 (forward → reverse or reverse → forward) can be released, and the forward / reverse rotation switching can be easily performed.

(5) In the above embodiment, the cylinder block 42 and the sleeve 41 are separate bodies. Therefore, for example, as compared with the cylinder block in which the sleeve 41 is omitted and the protrusion corresponding to the sleeve 41 is provided in the cylinder block 42, the cylinder block 4 of the present embodiment is
2 has a simple shape and can be easily manufactured. Also, the inner ring 3
By providing the sleeve 41 between the 9b and the cylinder block 42, the distance between the inner ring 39b and the cylinder block 42 can be arbitrarily set. Therefore, the cylinder block 4
2 can prevent interference due to arrangement with other components in the continuously variable transmission 20.

The above embodiment may be modified as follows. Although the sleeve 41 is provided in the above embodiment, the sleeve 41 may be omitted and the cylinder block 42 may be provided with a protrusion corresponding to the sleeve 41. And
The input end side of the projecting portion is the outer ring 39a of the conical roller bearing 39.
Abutting against. With this configuration, the same effect as that of the above-described embodiment can be obtained, and the number of parts can be reduced.

Although the sleeve 37 is provided in the above embodiment, it may be omitted. In the above embodiment, the structure of the gear shift device 138 may be changed to the structure of the gear shift device 150 (CST) shown in FIG.

In the gear shift device 150, the output gear 24 is formed at the protruding end of the yoke 23, as shown in FIG. A forward clutch 152 and a reverse clutch 153 that are connected to an output shaft 155 that transmits a driving torque to a final reduction gear (not shown) are provided. It also has the following gear trains.

The drive side clutch plate of the forward clutch 152 has a gear 151 meshed with the output gear 24. When the forward clutch 152 is connected by operating the shift lever 146, the yoke 23, the output gear 24, the gear 151, the forward clutch 152, and the output shaft 155.
The drive torque is transmitted to the final reduction gear device (not shown) via.

Further, the output gear 24 includes an idler gear 15
6, a reverse clutch 153 via an idler gear 157 and an intermediate gear 159 having a common shaft with the idler gear 156.
A gear train consisting of a gear 160 connected to the driving side clutch plate is connected. And the clutch mechanism 3
When the reverse clutch 153 is engaged by the backward operation of the shift lever 146 after disconnecting 00, the driving torque is transmitted to the final reduction gear device (not shown) via the gear train and the output shaft 155.

In this embodiment, the gear shift device 150
Corresponds to the “device for transmitting power in the same direction as the output rotating part or in the reverse direction”. In the above embodiment, the continuously variable transmission 20 and the hydraulic devices 100 and 200 used for the power transmission device may be used for other devices.

In the above embodiment, the sleeve 37 that abuts both the inner rings 38b, 39b is provided between the outer rings 38a, 39a of the conical roller bearings 38, 39 arranged opposite to each other.
8a and the bottom surface 34a of the step portion of the bearing housing hole 34 between the shim 5
0 is set. By adjusting the thickness of the shim 50, the preload of each of the conical roller bearings 38 and 39 is optimized when the nut 40 is screwed onto the input shaft 21. Not limited to this, when the shim 50 is omitted and the length of the step bottom surface 34a and the step bottom surface 35a of the side wall member 30 is set to the value when the nut 40 is screwed onto the input shaft 21,
The preload of each of the conical roller bearings 38 and 39 may be optimized.

In the above embodiment, the conical roller bearings 38 and 39 are used as the bearings for both thrust and radial, but the bearings are not limited to this, and angular ball bearings may be used as bearings for both thrust and radial. .

[0095]

As described above in detail, according to the inventions described in claims 1 to 3, even if the case thermally expands, the relative position of one wall of the case and the cylinder block does not change, and the cylinder It is possible to stabilize the support in the axial direction of the block.

According to the second aspect of the invention, the clearance between each bearing outer ring and one wall of the case can be adjusted, so that the preload of each bearing can be set appropriately. According to the third aspect of the present invention, since it is not necessary to extend the cylinder block to the thrust / radial bearing inner ring, the cylinder block has a simple shape and can be easily manufactured.

According to the invention of claim 4, claim 1
The effects described in any one of claims 3 to 3 can also be applied to the power transmission device.

[Brief description of drawings]

FIG. 1 is a sectional view of a continuously variable transmission according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB in FIG.

FIG. 3 is a sectional view taken along line AA of FIG.

FIG. 4 is a sectional view of the same main part.

FIG. 5 is a sectional view of the same main part.

6A is a perspective view of a retainer 70, and FIG. 6B is an enlarged view of a main part.

FIG. 7 is an explanatory view showing the timing when the ports are opened by the first switching valve 66 and the second switching valve 76.

FIG. 8 is a conceptual diagram of a power transmission device that also includes a continuously variable transmission.

FIG. 9 is a conceptual diagram of a continuously variable transmission that also shows the operation of the embodiment.

FIG. 10 is a conceptual diagram of a continuously variable transmission that also exhibits the same operation.

FIG. 11 is a plan view of a shifter.

FIG. 12 is a characteristic diagram similarly showing the stroke volume and the output rotation speed.

FIG. 13 is a conceptual diagram of a main part of a power transmission device according to another embodiment.

[Explanation of symbols]

20 ... Hydraulic continuously variable transmission (power transmission device), 21 ... Input shaft (rotating shaft), 22 ... Engine (motor), 23 Yoke (output rotating part), 26 ... Case, 30 ... Side wall member (one of case) Wall, and a case wall sandwiched between a pair of thrust / radial bearing outer rings, 37 ... Sleeve (first)
Spacer), 38, 39 ... Conical roller bearing (bearing for both thrust and radial), 38a, 39a ... Outer ring, 38b ... Inner ring (thrust / radial bearing inner ring on the side farther than the cylinder block), 39b ... Inner ring, 40 ... nut (fastening member), 41 ... sleeve (second spacer), 42 ... cylinder block, 43, 58 ... plunger, 44 ... swash plate surface (plunger contact portion), 46 ... locking flange (cylinder block contact) ), 138, 150 ... Gear shift device (device for transmitting power by matching with or rotating in reverse to the rotation direction of the output rotating part), 100 ... First hydraulic device (hydraulic device), 200 ... Second hydraulic device (hydraulic device) Device), 300 ... Clutch mechanism (device that turns on / off the rotation transmission to the rotating shaft of the prime mover).

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroshi Matsuyama             1-32 Yanma, Chayamachi, Kita-ku, Osaka-shi, Osaka             ー Diesel Co., Ltd. (72) Inventor Hisanori Mori             1-32 Yanma, Chayamachi, Kita-ku, Osaka-shi, Osaka             ー Diesel Co., Ltd. (72) Inventor Kunihiko Sakamoto             1-32 Yanma, Chayamachi, Kita-ku, Osaka-shi, Osaka             ー Diesel Co., Ltd. (72) Inventor Yukio Kubota             1-32 Yanma, Chayamachi, Kita-ku, Osaka-shi, Osaka             -Agricultural machinery Co., Ltd. F-term (reference) 3H070 AA01 BB05 BB06 BB16 CC37                       DD94                 3H084 AA08 AA16 AA45 AA51 AA60                       BB05 BB24 CC02 CC57 CC58                       CC64                 3J012 AB12 BB03 CB06 FB12 HB01                 3J017 AA02 AA05 BA01 DA01 DB02

Claims (4)

[Claims] 1. A hydraulic system in which a cylinder block having a plunger protruding in the axial direction is inserted into a rotary shaft and housed in a case, wherein a cylinder block abutting portion is provided on the rotary shaft, and a thrust / radial bearing inner ring is interposed. The thrust block, which is arranged so that the cylinder block abuts against the abutment portion from the side opposite to the abutment portion and faces the bearing outer ring and the bearing.
One wall of the case is sandwiched between the outer ring for the radial bearing and the fastening member is inserted into the rotary shaft, and the fastening member is pressed against the inner ring of the thrust / radial bearing on the side farther than the cylinder block. Hydraulic system characterized by. 2. A case in which a first spacer is inserted between the inner rings of the pair of thrust / radial bearings, and the axial length of the first spacer is sandwiched between the pair of thrust / radial bearing outer rings. The hydraulic pressure according to claim 1, wherein the wall length is configured to be longer than the axial length, and a clearance is provided between at least one outer ring of the pair of thrust / radial bearings and the case wall. apparatus. 3. A second spacer is inserted between the bearing inner ring and the cylinder block when the cylinder block is brought into contact with the abutting part from the side of the abutment part via the thrust / radial bearing inner ring. The hydraulic system according to claim 1 or 2, wherein the hydraulic system is configured. 4. A power transmission device using a hydraulic device according to any one of claims 1 to 3, wherein the hydraulic device has plungers projectingly inserted into both sides in an axial direction, and one side of the plungers is brought into contact with the plunger. Part, and has an output rotating part that performs either relative rotation or synchronous rotation with respect to input rotation by the protrusion of the plunger on the other side, and the rotating shaft is rotated by the output from the prime mover. A structure in which the output rotating portion is provided on the outer periphery of the extended rotating shaft, and a device for transmitting power in the same direction as the output rotating portion or in the reverse direction is provided. A power transmission device comprising a device for turning on and off rotation transmission to and from a rotary shaft.