JP2003014078A - Hydraulic continuously variable transmission and power transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic continuously variable transmission and a power transmission capable of easily performing the speed control of output rotation over the whole rotating speed range by the displacement of an abutting part. SOLUTION: This continuously variable transmission 20 is provided with a first hydraulic device 100 and a second hydraulic device 200. When a cradle 45 of the first hydraulic device 100 is displaced, the rotating speed of a yoke 23 is changed. A retainer 83 of the continuously variable transmission 20 reduces the stroke volume of the second hydraulic device 200 when the retainer 83 is positioned in a second working position in comparison with the case of being positioned in a first working position. When the retainer 83 is positioned into the second working position from the first working position, the rotating speed of the yoke 23 is further increased. It is constituted to allow the displacement of the cradle 45 (a swash plate face 44) regardless of the retainer 83 being located in either the first working position or the second working position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic continuously variable transmission 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 There is a hydraulic continuously variable transmission in which a variable displacement type hydraulic system having a maximum stroke volume and a differential hydraulic system are already combined to share a cylinder block of both and the cylinder block rotates. .

This hydraulic continuously variable transmission is connected to the input side and the output side of the hydraulic continuously variable transmission through the differential hydraulic device when the discharge amount of hydraulic oil from the variable displacement hydraulic device is zero. By directly connecting, it is possible to obtain a wide range of continuously variable transmission for both acceleration and deceleration centering on this direct connection.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a hydraulic continuously variable transmission and a power transmission device capable of easily controlling the speed of output rotation by displacing the contact portion over the entire rotation speed range. To do.

[0005]

In order to achieve the above-mentioned object, the invention according to claim 1 is provided with a first hydraulic device of variable capacity type, which comprises a plunger, and in which the plunger is pushed in and out by an abutment portion. , A second hydraulic device having a plunger and having an output rotating portion that performs either relative rotation or synchronous rotation with respect to input rotation by abutting of the plunger is combined, and a cylinder block that stores both plungers is shared, The cylinder block is configured to rotate in synchronization with the input rotation,
A hydraulic closed circuit that connects the first hydraulic device and the second hydraulic device is provided, and a distribution valve that switches the inflow and outflow of hydraulic oil by reciprocating motion is provided between the second hydraulic device and the hydraulic closed circuit, and the distribution valve reciprocates. In a hydraulic continuously variable transmission provided with a displacement mechanism for displacing the member to be displaced in the axial direction of the cylinder block, the axial fixed position of the member for reciprocating the distribution valve by the displacement mechanism is the first working position and the first position. The second working position, whose absolute value is smaller than the stroke volume at the working position,
The gist is that the contact portion of the first hydraulic device is configured to be displaceable when the member that reciprocates the distribution valve is in the holding state of the first operating position or the second operating position.

According to a second aspect of the present invention, in the hydraulic continuously variable transmission according to the first aspect, the member that reciprocates the distribution valve when the flow of hydraulic oil in the hydraulic closed circuit is stopped. The gist is that the rotational speed of the output rotating part is maintained regardless of whether the position is displaced to the first operating position or the second operating position.

According to a third aspect of the present invention, in the first or second aspect, an oil draining mechanism that operates to release the hydraulic pressure applied to the plunger of the second hydraulic device is provided. .

A fourth aspect of the present invention is based on the third aspect, and the gist is that the oil drain mechanism directly releases the hydraulic closed circuit to the outside of the cylinder block. According to a fifth aspect of the invention, in the third aspect, the oil draining mechanism directly releases a plunger hole for slidably accommodating the plunger of the second hydraulic device to the outside of the cylinder block. To do.

According to a sixth aspect of the present invention, the cylinder block of the hydraulic continuously variable transmission according to any one of the third to fifth aspects is connected to an input shaft that obtains input rotation from a prime mover. With this configuration, the input shaft is extended to the side opposite to the prime mover to form an output shaft, and the output rotating portion is provided on the outer periphery of the extended input shaft to transmit power to the output rotating portion. The gist is that a forward / reverse rotation switching device capable of reverse rotation switching is provided.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) The present invention is embodied below in a hydraulic continuously variable transmission (hereinafter referred to as continuously variable transmission 20) used as a working machine for traveling a working vehicle. The first embodiment will be described in detail with reference to FIGS.

As shown in FIG. 1, the continuously variable transmission 20 is housed in a case 26 of a power unit of a working vehicle. The continuously variable transmission 20 includes a closed hydraulic circuit C (FIGS. 9 to 1) between the first hydraulic device 100 and the first hydraulic device 100.
2) forming a second hydraulic device 200, which forms a first hydraulic pressure control device (see FIG. 1).

As shown in FIG. 9, an input shaft 21 of the continuously variable transmission 20 is connected to a crank shaft of an engine 22 as a prime mover, and an output gear 24 formed on a yoke 23 which will be described later on the output side is not shown. It is meshed with an input gear 25 connected to the speed reducer.

The first hydraulic device 100 corresponds to a variable displacement hydraulic device, and the second hydraulic device 200 corresponds to a differential hydraulic device. The case 26 of the continuously variable transmission 20 is a pair of a cylindrical tubular member 27 and a pair of bolts (not shown) that are integrally connected to each other through the bolt insertion holes 28 and 29 so as to close the openings at both ends of the tubular member 27. And side wall members 30 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. 5, at the center of the side wall member 30, a pair of bearing housing 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 is rotatably arranged in the through hole 36, and conical roller bearings 38, 39 are symmetrically fitted and fixed in the bearing receiving holes 34, 35 with the through hole 36 interposed therebetween. . The input shaft 21 is supported by the conical roller bearings 38 and 39. Further, the opening of the bearing housing hole 34 is covered with the cover 15 bolted to the side wall member 30. As shown in FIG. 5, the seal member 16 is provided in the through hole 15a of the cover 15.
The input shaft 21 is penetrated through.

As shown in FIG. 5, the outer ring 38a of the conical roller bearing 38 is in contact with the step portion of the bearing housing hole 34 through a shim 50. Also, the outer ring 39a of the conical roller bearing 39
Is in contact with a step portion on the inner side of the bearing housing hole 35.

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. When the nut 40 is screwed, the inner ring 38b of the conical roller bearing 38 presses the inner ring 39b of the conical roller bearing 39 via the sleeve 37, and further presses the sleeve 41 fitted to the input shaft 21. The sleeve 41 presses the cylinder block 42. Then, the cylinder block 42
Is brought into contact with a locking portion 46 provided on the outer periphery of the input shaft 21. Therefore, the cylinder block 42 can be fixed in the axial direction only by screwing the nut 40 from only the input end side. Further, by adjusting the number and thickness of the shims 50 interposed between the bearing outer ring 38a and the side wall member 30, the bearing 38,
The preload of each of the 39 can be adjusted.

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 cradle 45
Has an input shaft 21 penetrating therethrough. The swash plate surface 44 is
It corresponds to the swash plate of the variable displacement hydraulic device and also corresponds to the contact portion of the axial hydraulic device.

As shown in FIG. 3, the cradle 45 is supported so as to be tiltable with respect to the case 26 about a trunnion axis TR that is orthogonal to the axis O (axis) of the cylinder block 42. That is, the cradle 45
Is an upright position where a virtual plane including the swash plate surface 44 is orthogonal to the axis O. With reference to this upright position, the cradle 45 is tilted in the counterclockwise direction in FIG. 3 by a predetermined angle (first position) and in the upright position by a predetermined angle in the clockwise direction (reference position). Second position)
It is possible to tilt between.

In this embodiment, the clockwise direction is positive and the counterclockwise direction is negative in FIG. 3 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 in the first embodiment and its modification.

The swash plate surface 44 shown in FIG. 3 shows a state in which the cradle 45 is tilted at the negative maximum 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 is integrally connected to the input shaft 21 by spline 21a coupling. The cylinder block 42 has a substantially cylindrical combination shape, and both end circumferential surfaces located in the axial direction are smaller in diameter than the central portion.

In the center portion of the cylinder block 42, a plurality of plunger holes 47 are annularly arranged around the center of rotation (axis O) and extend in parallel with the axis O. The plunger hole 47 has an opening formed on the side of the cradle 45 on the step surface at the center of the cylinder block 42. Each plunger hole 47 has a plunger 43.
Are slidably arranged. A steel ball 48 is rollably fitted to the tip of the plunger 43, and the plunger 43 is in contact with the swash plate surface 44 via the steel ball 48 and the shoe 49 to which the steel ball 48 is attached. . Inclined swash plate surface 4
4 is the plunger 4 as the cylinder block 42 rotates.
3 is reciprocally actuated to impart the action of the suction and discharge strokes.

(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 54 is provided in the bearing housing hole 52.
Are fitted. A ball bearing 55 is fixed to the inner peripheral surface of the output end of the tubular member 27. The yoke 23 has a large-diameter portion and a small-diameter portion. 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 that the yoke 23 is 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. An output gear 24 is formed at the protruding end of the yoke 23.

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,
Around the center of rotation, the same number of plunger holes 57 as the plunger holes 47 are annularly arranged 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. or,
Each plunger hole 57 is adjacent to the other plunger hole 47.
As shown in FIG. 2, it is arranged so as to be located between them and in the circumferential direction of the cylinder block 42 so as to be offset from the plunger holes 47 by 1/2 pitch.

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 rotating slope 5 through the shoe 60 to which the steel ball 59 is attached.
1 is abutted. 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 system 100 is formed to be substantially the same as the maximum stroke volume VMmax of the second hydraulic system 200. However, strictly speaking, VPmax is slightly larger and has a difference Δ1. Specifically, in the present embodiment, the maximum tilt angle of the swash plate surface 44 of the first hydraulic device 100 is the second hydraulic device 20.
The difference between the maximum stroke volumes is obtained by setting the inclination angle of the rotary slope 51 to be larger than 0.

(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.

In the cylinder block 42, the same number of first valve holes 63 as those communicating with the first oil chamber 61 and the second oil chamber 62 are provided along the axial direction of the cylinder block 42, as many as the plunger holes 47. There is. In addition, the cylinder block 42 has a second oil chamber 61 and a second oil chamber 62 that communicate with each other.
The same number of valve holes 64 as the plunger holes 57 are provided along the axial direction of the cylinder block 42.

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 that they are 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 between 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. 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. The retainer 70 includes a cylindrical tubular portion 71, and a flange 72 that is formed so as to project from the end of the tubular portion 71 on the cylinder block 42 side.
1 and 5, the retainer 70 is arranged so that its axis intersects with the axis O by the ball bearing 69, and in this state, the input shaft 21 is rotatable. It is penetrated. 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. 7A, on the flange 72 of the retainer 70, locking grooves 73 are formed by cutting from the outer circumference toward the axis center at equal angles around the axis center. As shown in FIG. 7B, 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 obliquely intersecting with the axis O, whereby the first switching valve 66 shown in FIG.
A displacement as shown in is realized. As shown in FIG. 8, the flange 72 of the retainer 70 has a first opening position n1 that allows the first switching valve 66 to communicate with the port U and the second oil chamber 62 about the port closing position n0, and a port U. It reciprocates between the second opening position n2 that communicates with the first oil chamber 61. Then, with this retainer 70, the first hydraulic device 1
00 corresponds to the rotation direction around the axis O of the cylinder block 42 as shown in FIGS.
A region H is given in the range of 0 °, and a region I is given in the range of 180 ° to 360 ° (0 °).

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 changes from 0 to VPmax, and accordingly. When the input rotation speed of the input shaft 21 is Nin, the output rotation speed Nout (the rotation speed of the output gear 24) is Nin.
In the present embodiment, the discharge amount of hydraulic oil on the side of the first hydraulic device 100 is set so as to obtain a speed in the range from 1 to 2.7 Nin.

In FIG. 12, the vertical axis represents the stroke volumes 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 rotary portion). In the figure, the solid line indicates the first hydraulic device 100.
Of the stroke volume VP, and the alternate long and short dash 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 within 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 second valve hole 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. 6, a storage hole 78 is formed in the center of the end surface of the yoke 23 on the cylinder block 42 side. In the storage hole 78, a cylindrical holder 79 is fitted on the outer periphery of the input shaft 21 so as to be slidable along the axis O and to rotate integrally with the input shaft 21 by a pin 128. A cylindrical support member 81 is attached to the holder 79 via a ball bearing 80 so as to be rotatable in synchronization with the yoke 23. The support member 81 is slidably fitted along the axis O through a plurality of pins 82 fixed to the bottom of the housing hole 78 of the yoke 23. Support member 8
A retainer 83 is rotatably connected to the inner circumference of the bearing 1 through a ball bearing 84 and is slidable along the axis O. “Member that moves to the cylinder block side” in the holder 79, ball bearing 80, support member 81, and ball bearing 84
Is configured. The retainer 83 corresponds to a member that reciprocates the distribution valve.

The retainer 83 has a cylindrical portion, a flange, and a locking groove that have the same structure as that of the retainer 70. Therefore, the same reference numerals are given to the respective structures and the description thereof will be omitted.

As shown in FIG. 6, 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 holder 7 is provided on the outer peripheral surface of the input shaft 21.
The locking ring 12 is provided on the output end side with respect to the position where 9 is located.
5 is fixed, and can be locked by the locking ring 125 when the holder 79 moves to the output end side.

For this reason, the retainer 83 is arranged so as to be oblique to the axis O and the support member 81 and the ball bearings 80, 8 are provided.
4. The holder 79 and the holder 79 can move integrally along the axis O.

A coil spring 126 as an urging means wound around the outer peripheral surface of the input shaft 21 is arranged between the locking portion 46 and the holder 79. The urging force of the coil spring 126 causes the retainer 83 to move. The input shaft 21 is constantly urged toward the output end side.

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, whereby the second switching valve 76 shown in FIG.
A displacement as shown in is realized. Note that, in FIG. 8, 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 rotation part) 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. 3, 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.

As shown in FIG. 4, a pair of valve accommodating holes 85 and 86 are provided at positions from the outer periphery of the cylinder block 42 corresponding to the first oil chamber 61 and the second oil chamber 62, respectively. It is arranged in parallel with. The bottom of both valve storage holes 85 and 86 are
The valve accommodating holes 85 are connected to each other by a through hole 87 having a diameter smaller than that of the valve accommodating hole 85. In addition, openings 88, 89 that are open to the outside are formed in the stepped surface of the central portion of the cylinder block 42 in both valve storage holes 85, 86. A pair of charge valves (check valves) 90, 9 are provided in both valve storage holes 85, 86.
1 is arranged.

Since the charge valves 90 and 91 have the same structure,
The configuration of the charge valve 90 will be described, and the charge valve 91 will be described.
The same components are designated by the same reference numerals and the description thereof will be omitted.

The case body 92 of the charge valve 90 is formed in a cylindrical shape. A communication hole 92a is formed in the peripheral wall of the case body 92 to communicate the inside and the outside. In the case body 92, an opening on one end side is closed by a plug body 93, and a valve seat 95 of a valve body 94 made of a steel ball is formed on the opening portion on the other end side. A coil spring 96 is housed between the valve body 94 and the plug body 93, and the valve body 94 closes the valve seat 95 by the coil spring 96.

Further, the case body 9 of each charge valve 90, 91
2 is slidably arranged in the length direction (direction parallel to the axis O) of the valve housing holes 85 and 86. C-shaped spring locking rings 88a and 89a are fixed to the inner peripheral surfaces of the openings 88 and 89 of the valve storage holes 85 and 86, respectively. Coil springs 97 and 98 are interposed between the spring locking rings 88a and 89a and the charge valves 90 and 91, respectively, and bias the charge valves 90 and 91 to the bottom side of the valve housing holes 85 and 86. It is supposed to do. Coil spring 9
The urging force of 7,98 will be described later.

Communication oil passages 61a, 6 are provided between the first oil chamber 61 and the valve housing hole 85 and between the second oil chamber 62 and the valve housing hole 86.
2a is formed. In order to charge the hydraulic closed circuit C with hydraulic oil, a shaft hole 99 is bored along the shaft center O in the input shaft 21. The shaft hole 99 has an introduction oil passage 99a in the radial direction at a portion corresponding to the sleeve 37 (see FIG. 3). The introduction oil passage 99a has a sleeve 37
It is communicated with the oil passage 37a formed in the radial direction and the circumferential groove 37b formed in the outer peripheral surface. The side wall member 30 is provided with an oil passage 30a communicating with the circumferential groove 37b.
The hydraulic oil is pumped into the inside from a charge pump (not shown).

As shown in FIG. 4, in the input shaft 21 and the cylinder block 42, branch passages 99b, 42a communicating with the shaft hole 99 are formed in the portion facing the through hole 87. The hydraulic oil pumped into the shaft hole 99 is the branch passage 99b,
42a, the through hole 87, and the charge valves 90 and 91 fill the hydraulic closed circuit C. That is, the charge valve 9
The valve bodies 94 of 0 and 91 open until the pressure in the hydraulic closed circuit C reaches the charge pressure in the shaft hole 99, and supply the hydraulic oil in the shaft hole 99 to the hydraulic closed circuit C. Also, the charge valves 90, 9
1 prevents the hydraulic oil from flowing back to the shaft hole 99.

The urging force of the coil springs 97, 98 resists the urging force of the coil springs 97, 98 by a predetermined charge pressure of the hydraulic oil, and reaches a position where the communication hole 92a communicates with the communication oil passages 61a, 62a. The case body 92 is set to be movable. On the charge valve 90 side in FIG. 4, the charge valve 90 is located up to a position where the communication hole 92a communicates with the communication oil passages 61a, 62a against the biasing force of the coil spring 96 due to the predetermined charge pressure of the hydraulic oil. It shows the state. In the figure, the arrow α indicates from the shaft hole 99 to the branch paths 99b and 42a and the through hole 8.
7, the flow of the hydraulic oil passing through the valve housing hole 85, the communication hole 92a, and the communication oil passage 61a is shown.

When the charge pressure decreases, the charge valve 9 is urged by the urging force of the coil springs 97 and 98.
The case bodies 92 of 0 and 91 are brought into contact with the bottoms of the valve housing holes 85 and 86. At this time, the communication oil passages 61a and 62a are communicated with the outside of the cylinder block 42 through the openings 88 and 89 of the valve storage holes 85 and 86, and the hydraulic oil in the hydraulic closed circuit C is released to the outside. That is, the hydraulic closed circuit C is directly released to the outside of the cylinder block 42.

On the charge valve 91 side in FIG. 4, when the hydraulic oil drops below a predetermined charge pressure, the case body 92 of the charge valve 91 is brought into contact with the bottom of the valve housing hole 86 by the urging force of the coil spring 98. , The communication oil passage 62a is in communication with the outside through the opening 89 of the valve housing hole 86. In the figure, the β arrow indicates the movement locus of the hydraulic oil flowing from the second oil chamber 62 to the outside of the cylinder block 42 via the communication oil passage 62a, the valve storage hole 86, and the opening 89.

In FIG. 4, for convenience of explanation, the communication hole 92a is formed on the charge valve 90 side so that the communication oil passage 61 is formed.
Although a state of communicating with a is shown and a state of the communication oil passage 62a on the side of the charge valve 91 is shown communicating with the opening 89 of the valve housing hole 86, such a state does not occur at the same time.

(Oil draining section 110) Next, the oil draining section 110
Will be described. As shown in FIG. 4, in the input shaft 21, peripheral grooves 21c and 21d are formed on the peripheral surface facing the first oil chamber 61 and the second oil chamber 62. As shown in FIG. 6, an oil drain portion 110 is formed on the input shaft 21. The oil removing portion 110 is provided on the outer peripheral surface of the input shaft 21.
Groove portion 111 extending in the axial direction and connected to the circumferential groove 21d.
And an oil passage 112 which is formed in the radial direction of the input shaft 21 from the end of the groove portion 111 and communicates with the shaft hole 99. As shown in FIG. 6, the shaft hole 99 has an introduction oil passage 99a.
And the small diameter portion 11 communicating with the branch passage 99b (see FIG. 3).
3, medium diameter portion 114 adjacent to the small diameter portion 113, medium diameter portion 11
4 and a large diameter portion 115 that is open to the output end face of the input shaft 21. Each part 113-115
Are formed to be coaxial.

The inner end of the oil passage 112 of the oil draining portion 110 is communicated with the medium diameter portion 114 of the shaft hole 99 through the throttle portion 112a. The shaft hole housing member 116 is slidably housed in the medium diameter portion 114 and the large diameter portion 115. The shaft hole accommodating member 116 corresponds to “a member that moves in the axial direction inside the input shaft”. The shaft hole accommodating member 116 is formed in a spool valve shape. The shaft hole accommodating member 116 includes the medium diameter portion 11
4, the first land 117 slidably fitted to the fourth land 118, the second land 118 slidably fitted to the large-diameter portion 115, and the first land 117 and the second land 118 are connected to each other. A connecting portion 119 having a diameter smaller than that of the land is provided.

The axial length of the first land 117 is shorter than the axial length of the medium diameter portion 114. Then, the first land 117 is the locking step portion 11 between the small diameter portion 113 and the medium diameter portion 114.
4a, when the first land 117 is engaged with the oil passage 11
The opening end of the second throttle 112a is located so that it can be opened (see FIG. 6). An axially extending hole 120 (see FIG. 4) is formed in the connecting portion 119 and the first land 117, one end of which is opened in the peripheral surface of the connecting portion 119, and the other end of which is the first land 117. It is opened at the end surface on the side of the small diameter portion 113.

As a result, the first land 117 has the small diameter portion 11
3 and the medium diameter portion 114 are locked to the locking step portion 114a, the working oil in the second oil chamber 62 is the circumferential groove 21d and the oil draining portion 1.
10 (groove portion 111, oil passage 112, throttle portion 112a) to the intermediate diameter portion 114 of the shaft hole 99. Then, the hydraulic oil that has flowed into the medium diameter portion 114 is passed through the hole 120 and the shaft hole 99.
To the small diameter portion 113. Since the throttle 112a is provided, the amount of hydraulic oil flowing out to the small diameter portion 113 is limited and is small.

When the first land 117 moves to the output end side of the input shaft 21, the opening of the oil passage 112 on the side of the throttle 112a is closed. Further, the second land 118 has a substantially frustoconical tapered portion 11 having a tapered surface whose diameter gradually decreases toward the anti-coupling portion side (that is, the output end side of the input shaft 21).
8a and the large diameter portion 1 provided at the tip of the tapered portion 118a.
15 and a spring locking portion 118b that is slidably contactable.

As shown in FIGS. 1 and 3, in the large diameter portion 115 of the shaft hole 99, a plug 121 is screwed into the opening on the output end side of the input shaft 21 so that the screwing amount can be adjusted. There is. or,
A stopper member 122 of the shaft hole housing member 116 is screwed along the axis of the plug 121. Axial hole storage member 116
The inner end of the stopper member 122 extends in the large diameter portion 115 along the axial direction. A coil spring 124 is interposed between the plug 121 and the spring locking portion 118b of the second land 118. Coil spring 124
Due to the urging force of the shaft hole housing member 116, the shaft hole housing member 116 is locked to the locking step portion 114a at a normal charge pressure.
Further, the biasing force of the coil spring 124 can be adjusted by adjusting the screwing amount of the plug body 121.

When a charge pump (not shown) is driven to pump the hydraulic oil into the shaft hole 99 in order to obtain a larger charge pressure than the biasing force of the coil spring 124, the shaft hole housing member 116 causes the coil spring 124 to move. The pressure receiving area of the input shaft 21 is set so as to be movable to the output end side of the input shaft 21 against the urging force of. By this movement, the shaft hole housing member 116 can close the opening end portion of the oil passage 112 on the throttle portion 112a side.

The stopper member 122 of the shaft hole accommodating member 116 limits the maximum movement amount of the shaft hole accommodating member 116 when it moves to the output end side. (Displacement mechanism D) In the input shaft 21, the locking ring 125
At the position corresponding to the holder 79 locked to the pin hole 12
7 is formed to extend in the radial direction and communicates with the large diameter portion 115 of the shaft hole 99. An operating pin 128 is slidably arranged in the pin hole 127 in the radial direction of the input shaft 21. The operation pin 128 corresponds to a “member that projects in the radial direction of the input shaft”.

The shaft hole housing member 116 and the operating pin 12
8, the holder 79, the ball bearing 80, the support member 81, and the ball bearing 84 constitute a displacement mechanism D. The displacement mechanism D is provided so as to be close to the input shaft 21. Further, the displacement mechanism D is disposed in the inner space (accommodation hole 78) of the yoke 23.

On the inner peripheral surface of the holder 79, the pin hole 12
7, a taper groove 129 is provided along the length direction of the holder 79. The bottom surface of the tapered groove 129 is separated from the shaft center of the holder 79 (corresponding to the shaft center O of the input shaft 21) as it approaches the locking ring 125 side (that is, the output end side of the input shaft 21). Is formed obliquely with respect to the axis center of. That is, the taper groove 129 is inclined in the direction opposite to the taper portion 118a of the shaft hole housing member 116, and the slope of the bottom surface thereof is steeper than that of the taper portion 118a. It should be noted that the steep slope referred to here means that when the tapered portion is moved along the direction of the axis O, the degree of separation from the axis O is large.

The operation pin 128 has an inner end abutting on the tapered portion 118a of the shaft hole accommodating member 116 and an outer end abutting on the bottom surface of the tapered groove 129 of the holder 79. When the holder 79 is in contact with the locking ring 125, the operating pin 128 is in contact with the proximal end side of the bottom surface of the tapered groove 129. In addition, hereinafter, the operating pin 12
The position of the retainer 83 when 8 abuts on the proximal end side of the bottom surface of the tapered groove 129 is referred to as a first acting position.

When the operating pin 128 moves in the radial direction about the axis O of the input shaft 21, the holder 79 is moved through the bottom surface of the tapered groove 129 to the coil spring 1.
It can be moved to the input end side of the input shaft 21 against the urging force of the input shaft 26 and can be brought into contact with the distal end side of the bottom surface of the tapered groove 129. In the following description, the operating pin 128 is attached to the taper groove 129.
The position of the retainer 83 when it abuts on the distal end side of the bottom surface of the is referred to as a second action position.

By moving the pressing position of the actuating pin 128 from the proximal end side to the distal end side of the taper groove 129, the displacement end of the second switching valve 76 engaged with the flange 72 of the retainer 83 is moved to the input shaft 21. It is designed to be displaced to the input end side of.

In this embodiment, the inclination of the tapered portion 118a of the shaft hole accommodating member 116 is determined by the holder 7 as described above.
The taper groove 129 of No. 9 is formed more gently. Therefore, the amount of displacement of the shaft hole housing member 116 (first displacement amount) and the amount of displacement of the retainer 83 (second displacement amount).
The amount of displacement) is such that the amount by which the shaft hole housing member 116 is displaced increases.

The coil spring 126 is used for the input shaft 2
Even if 1 rotates and a centrifugal force is applied to the actuating pin 128 in the radial direction, the urging force is set so that the holder 79 does not move to the input end side of the input shaft 21.

The displacement of the displacement end of the second switching valve 76, that is, the ratio of the regions J and K in one cycle changes as shown in FIGS.
At the port W so that the absolute value of the maximum stroke volume of the second hydraulic device 200 changes from VMmax to 0.6VMmax.
It is set so that the opening and closing timing of can be changed.

Hereinafter, the displacement position of the second switching valve 76 when the retainer 83 is located at the first operating position will be referred to as the first displacement position R1, and the second displacement position when the retainer 83 is located at the second operating position. The displacement position of the switching valve 76 is referred to as the second displacement position R2 (see FIG. 8). Therefore, the second switching valve 76 operates along the line indicated by the first displacement position R1 or the second displacement position R2 in FIG.

(Operation) The operation of the continuously variable transmission 20 configured as described above will now be described. In the following description of the present embodiment and other embodiments, the input rotation speed Nin applied to the input shaft 21 from the crankshaft of the engine 22 is constant for convenience of description.

(When the output speed Nout is Nin) A shift lever (not shown) is operated to position the swash plate surface 44 at the upright position via the cradle 45.

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. Hereinafter, rotation in the same direction as 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, in this state, the input shaft 21 and the output gear 24 are directly connected. The rotation in the forward direction imparted to the rotary slope 51 is caused by the yoke 23, the output gear 24,
It is transmitted to the final reduction gear via the input gear 25.

When the swash plate surface 44 is in the upright position, the stroke volume VP of the first hydraulic system 100 becomes 0 as shown in FIG. 12, and the output speed Nout (output gear 2
The rotation speed of 4) is the input rotation speed Nin.

(When the output speed Nout exceeds Nin)
First, with the swash plate surface 44 in the upright position,
That is, while the hydraulic oil in the hydraulic closed circuit C is not circulating, the charge pump (not shown) is driven to pressurize the hydraulic oil in the shaft hole 99.

Then, the shaft hole housing member 116 moves to the output end side of the input shaft 21 against the urging force of the coil spring 124, and closes the opening end of the oil passage 112 on the throttle portion 112a side.

Further, the movement of the shaft hole accommodating member 116 toward the output end of the input shaft 21 causes the operating pin 128 to move toward the taper portion 11.
It is pressed by 8a and moves in the radial direction from the axis O of the input shaft 21. The actuating pin 128 is displaced from the proximal end to the distal end of the bottom surface of the tapered groove 129 of the holder 79. Therefore, the holder 79 moves to the input end side of the input shaft 21 against the biasing force of the coil spring 126 by the pressing of the operation pin 128. As a result, the operating pin 128 has the taper groove 1
When abutting the distal end of the bottom surface of 29, the retainer 83
After moving from the operating position to the second operating position, the displacement end of the second switching valve 76 switches from the first displacement position R1 to the second displacement position R2.

Then, the section communicating with the port W and the second oil chamber 62 becomes narrower, and the section communicating with the port W and the first oil chamber 61 becomes wider. That is, the area J is exceeded when Nin is exceeded.
Becomes wider and the region K becomes narrower as shown in FIG. As a result, as shown in FIG. 13B, the amount of hydraulic oil per stroke that flows from the plunger hole 57 to the second oil chamber 62 through the port W is from the first oil chamber 61 to the port W.
It becomes less than the amount of hydraulic oil per stroke that flows into the plunger hole 57 through.

Therefore, the second oil chamber 6 of the second hydraulic device 200 is
The stroke volume communicating with 2 is 0.6VMmax. By operating a shift lever (not shown), the swash plate surface 44 is tilted to the negative side through the cradle 45 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 of the stroke volume VM of the second hydraulic device 200 (= 0.6VMmax). .

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, transmitted as positive rotation to the final reduction gear transmission through the output gear 24 and the input gear 25, and accelerates.

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 rotation speed Nout from Nin is 2.
Speed up to 7 Nin.

The output speed Nout is 2.7 from Nin.
Stroke volume V of the second hydraulic device 200 when changing to Nin
M remains at 0.6 VMmax. The flow and rotation of the hydraulic oil in this state are shown in FIG. In this embodiment, in this state, the oil drain portion 110 is closed.

On the contrary, Nout is changed from "Nout>Nin" to "Nout".
When changing to out <Nin, the displacement end of the second switching valve 76 is switched from the second displacement position R2 to the first displacement position R1 and changes from 0.6VMmax to -VMmax.

(When the output rotational speed Nout is between 0 and Nin) In this state, the shaft hole housing member 116 is urged by the coil spring 124.
Is always locked to the locking step portion 114a, a small amount of hydraulic oil flows from the second oil chamber 62 (that is, the hydraulic closed circuit C) to the small diameter of the shaft hole 99 via the oil draining portion 110 and the hole 120. It is allowed to flow out to the portion 113. That is, the displacement end of the second switching valve 76 is located at the first displacement position R1.

By operating a shift lever (not shown), the swash plate surface 44 is tilted to the positive side through the cradle 45 to be positioned in the region of the positive tilt angle position from the upright position. Of the positive tilt angle positions, the predetermined positive tilt angle position is
This is the position until the absolute value of the stroke volume VP of the first hydraulic device 100 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, the cylinder block 42 rotates via the input shaft 21 by the driving force of the engine 22. Then, the first hydraulic device 100 discharges the hydraulic oil from the plunger hole 47 through the port U within the range of the rotation angle of the cylinder block 42 around the axis O of 0 ° to 180 °, and 180 ° to 360 ° ( 0
In the range of (°), the hydraulic oil is sucked into the plunger hole 47 through 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. 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, in the second hydraulic device 200, the relative rotation angle of the yoke 23 (output rotation portion) with respect to the cylinder block 42 about the axis O is 0 ° to 180 °.
In the range of °, hydraulic oil is supplied through the port W to the plunger hole 5
Discharge from 7 and in the range of 180 ° to 360 ° (0 °),
The hydraulic oil is sucked into the plunger hole 57 via 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 rotation slope 51 of the plunger 58 is
The output pressing speed Nout is N
Between "in" and "2Nin" and "when exceeding 2Nin", rotation in the opposite direction is given. Therefore, the yoke 23 and the output gear 24 are rotated by combining (summing) the rotational speed in the reverse direction and the rotational speed in the positive direction of the cylinder block 42. Since the sum of the rotation speeds at this time becomes the rotation speed in the forward direction which is decreased by the rotation speed in the reverse direction, the output rotation speed Nout is equal to the “output rotation speed Nou”.
When t is Nin ”, it becomes smaller.

In this embodiment, at this time, when the swash plate surface 44 is displaced from the upright position to the side of the predetermined positive tilt angle position, the stroke volume VP of the first hydraulic system 100 in FIG.
Increases from 0 to -VMmax (the above "-" means the case where the oil is discharged from the port U to the second oil chamber 62), and the output speed Nout changes from Nin to 0 accordingly. Slow down.

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 a case where the second oil chamber 62 is sucked into the port W.) In this state, in the same manner as described above, through the oil draining portion 110 and the like,
A small amount of hydraulic oil flows out from the second oil chamber 62 (that is, the hydraulic closed circuit C) to the small diameter portion 113 of the shaft hole 99, causing some loss. However, the amount of hydraulic oil flowing out is small, and the second oil chamber 62 (oil chamber B) side is closer to the first oil chamber 61.
Since the pressure is lower than that on the (oil chamber A) side and the operating efficiency of the plunger 58 that presses the yoke 23 for deceleration is not reduced, there is no problem.

FIG. 10 is a schematic diagram of the state at this time. The first oil chamber 61 (oil chamber A) side is on 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 is as shown by the arrow in the figure.

(When the output rotational speed Nout is 0) Next, the shift lever (not shown) is operated to move the swash plate surface 44 through the cradle 45 to the first hydraulic system 100 at the predetermined positive tilt angle position. Is set at a position where the absolute value of the stroke volume VP is equal to the absolute value of the stroke volume VM of the second hydraulic device 200.

In this case, in this embodiment, the first hydraulic device 1
The stroke volume VP of 00 is -VMmax. As a result, the rotational speed in the opposite direction and the cylinder block 42 are
Is balanced with the rotational speed Nin driven through, that is, the total rotational speed is 0 (output rotational speed Nout is 0),
The output gear 24 is stopped.

In this state, when the swash plate surface 44 is further tilted to the positive side from the predetermined positive tilt angle position via the cradle 45, the stroke volume V of the first hydraulic system 100 is increased.
The absolute value of P is the stroke volume VM (=
It falls within a range that is larger than the absolute value of (VMmax).

Therefore, the stroke volume V of the second hydraulic system 200 is relative to the absolute value of the stroke volume VP of the first hydraulic system 100.
Since the absolute value of M is relatively small, it should be the second
In the hydraulic system 200, in order to compensate for this, the second hydraulic system 20
The reciprocating speed of the zero plunger 58 should be increased.

However, at this time, the second oil chamber 62 is at a higher pressure side than the first oil chamber 61 side, and the working oil is discharged from the second oil chamber 62 (that is, the hydraulic closed circuit C) to the oil draining portion 110 or the like. The high-pressure hydraulic oil flows out to the small diameter portion 113 of the shaft hole 99 via the. When the maximum loss amount flowing out from the hydraulic closed circuit C when the cylinder block 42 makes one rotation is L, the absolute value of the stroke volume VP of the first hydraulic device 100 and the second hydraulic device 200.
Difference with absolute value of stroke volume VM (| VP |-| VM |)
However, as long as | VP | − | VM | ≦ L (= Δ1) is satisfied, | VP | and | VM | + the loss amount are balanced, so that the second hydraulic device 200 continues to operate in the reverse direction. The number of rotations and the cylinder block 42 indicate that the input shaft 21
Is balanced with the rotational speed Nin driven through, that is, the total rotational speed is 0 (output rotational speed Nout is 0),
The output gear 24 maintains the stopped state (neutral).

In FIG. 12, Δ1 is | VP | − | VM
| Indicates the stroke volume difference between both devices from 0 to L. Note that, in FIG. 12, the Δ1 portion is enlarged and illustrated for convenience of description.

(When the output rotation speed Nout is less than 0) First, the swash plate surface 4 is left in the state where the output rotation speed Nout is 0.
Processing for displacing No. 4 from the positive maximum tilt angle position to a position where the stroke volume VP of the first hydraulic device 100 is −0.6 VMmax (hereinafter, referred to as a specific position) is performed. When performing this processing, the swash plate surface 44 is displaced from the positive maximum tilt angle position to the specific position, and at the same time, the second hydraulic device 2 is moved.
By changing the stroke volume VM of 00 from -VMmax to -0.6VMmax, the output rotation speed Nout is kept at 0 state.

When the stroke volume VM of the second hydraulic system 200 is changed from -VMmax to -0.6VMmax, it is not shown, as described in "When the output speed Nout exceeds Nin". By driving the charge pump to pressurize the hydraulic oil into the shaft hole 99, the second switching valve 76 is moved from the first displacement position R1 to the second displacement position R2. At this time, the retainer 83 is moved from the first operating position to the second operating position. Further, in this state, the oil draining section 110
Is blocked.

Therefore, as shown in FIG. 13B, the section communicating with the port W and the second oil chamber 62 is narrowed, and the port W
And a section communicating with the first oil chamber 61 becomes wider. As a result, the stroke volume communicating with the second oil chamber 62 of the second hydraulic device 200 becomes 0.6VMmax.

Then, when the output speed Nout is set to less than 0, the following is performed. By operating a shift lever (not shown), the swash plate surface 44 is tilted to the positive side through the cradle 45 to be positioned in the area of the positive tilt angle position from the specific position.

In this case, since the swash plate surface 44 tilts in the positive direction, the cylinder block 42 rotates via the input shaft 21 by the driving force of the engine 22. Then, the first hydraulic device 100 discharges the hydraulic oil from the plunger hole 47 through the port U within the range of the rotation angle of the cylinder block 42 around the axis O of 0 ° to 180 °, and 180 ° to 360 ° ( 0
In the range of (°), the hydraulic oil is sucked into the plunger hole 47 through 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. 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, in the second hydraulic device 200, the relative rotation angle of the yoke 23 (output rotation portion) with respect to the cylinder block 42 about the axis O is 0 ° to 180 °.
In the range of °, hydraulic oil is supplied through the port W to the plunger hole 5
Discharge from 7 and in the range of 180 ° to 360 ° (0 °),
The hydraulic oil is sucked into the plunger hole 57 via 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.

Further, the stroke volume VP of the first hydraulic system 100
Is the stroke volume VM (= 0.6VMm of the second hydraulic device 200).
Range larger than ax) (0.6VMmax <VP ≦ VMm
ax). Therefore, with respect to the stroke volume VP of the first hydraulic apparatus 100, the stroke volume VM of the second hydraulic apparatus 200 is
Is relatively small, so in the second hydraulic device 200,
To compensate for this, the reciprocating speed of the plunger 58 of the second hydraulic device 200 becomes faster.

As a result, the rotary slope 51 of the plunger 58 is
The output pressing speed Nout is N
Between "in" and "2Nin" and "when exceeding 2Nin", rotation in the opposite direction is given. Therefore, the yoke 23 and the output gear 24 are rotated by the rotation speed in the opposite direction. The rotation speed at this time becomes smaller than that when the output rotation speed Nout is zero.

In this embodiment, when the swash plate surface 44 is displaced from the specific position to the positive tilt angle position side at this time, as shown in FIG.
2, the stroke volume VP of the first hydraulic device 100 increases from 0 to −VMmax (the “−” means the case where the second hydraulic chamber 62 is discharged from the port U), and accordingly. As a result, the output speed Nout is decelerated from 0 to approximately -0.7 Nin.

The second hydraulic device 200 when the output speed Nout at this time changes from 0 to approximately -0.7 Nin.
The stroke volume VM per one rotation of is -0.6VMmax. (The “−” means the case where the second oil chamber 62 is sucked into the port W.) At this time, when the swash plate surface 44 is displaced from the specific position to the positive tilt angle position side, FIG.
In, the stroke volume VP of the first hydraulic device 100 is -0.6.
It increases from VPmax to -VPmax, and accordingly the output speed Nout increases from 0 to approximately -0.7Nin.

FIG. 11 is a schematic view of the state at this time. The first oil chamber 61 (oil chamber A) side is on a lower pressure side than the second oil chamber 62 (oil chamber B) side, and in the hydraulic closed circuit C,
The flow of hydraulic oil is as shown by the arrow in the figure.

According to this embodiment, the following effects can be obtained. (1) In the continuously variable transmission 20 (hydraulic continuously variable transmission) of the present embodiment, the plunger 43 is used as the first hydraulic device 100.
And cradle 45 that is not rotatable around the axis O
The swash plate surface 44 (abutting portion) is used to cause the plunger 43 to project. Further, as the second hydraulic device 200, the plunger 58 is provided, and the yoke 23 (output rotating part) that performs either relative rotation or synchronous rotation with respect to the input rotation by the projection insertion of the plunger 58 is provided. The cylinder block 42 accommodating the plungers 43 and 58 of both the first hydraulic device 100 and the second hydraulic device 200 is shared, and the cylinder block 42 is configured to rotate in synchronization with the input rotation.

First hydraulic system 100 and second hydraulic system 200
A hydraulic closed circuit C communicating with the second hydraulic device 200 is provided.
The second switching valve 76 for switching the inflow and outflow of the hydraulic oil by the reciprocating motion is provided between the hydraulic circuit and the hydraulic closed circuit C. Further, the second
A retainer 83 (a member that reciprocates the distribution valve) that reciprocates the switching valve 76 is provided, and a displacement mechanism D that displaces the retainer 83 along the axis O is provided.

At the axially fixed position of the retainer 83 by the displacement mechanism D, the stroke volume VM of the second hydraulic device 200 is V
First working position of Mmax (-VMmax) and same stroke volume V
It was set to the second operating position where M was 0.6 VMmax (-0.6 VMmax). The swash plate surface 4 of the first hydraulic device 100 when the retainer 83 is in the holding state of the first operating position and the second operating position.
4 (cradle 45) is configured to be displaceable.

By the way, in the conventional hydraulic continuously variable transmission,
The output rotation is changed between 0 and medium speed by changing the discharge amount of the hydraulic oil of the variable displacement hydraulic device. Further, the conventional hydraulic continuously variable transmission is capable of changing the timing of the hydraulic oil flowing into the plunger hole of the differential hydraulic device while keeping the discharge amount of the hydraulic oil of the variable displacement hydraulic device at the maximum. The output rotation was changed between medium speed and high speed. However, in the conventional hydraulic continuously variable transmission, a part of the mechanism for changing the timing of the hydraulic oil flowing into the plunger hole of the differential hydraulic device rotates together with the output rotating part, so that it moves into the plunger hole. It is difficult to subtly change the hydraulic oil inflow timing of. As a result, it has been difficult to control the output speed from medium speed to high speed.

In comparison, the continuously variable transmission 2 of this embodiment
0 is the first hydraulic device 100 when the retainer 83 is in the first operating position or in the second operating position.
The continuously variable transmission 20 controls the speed of the output speed Nout from the reverse rotation to the high-speed forward rotation only by displacing the swash plate surface 44 (cradle 45) (in this embodiment, approximately -0.7 Nin). It can be easily performed by displacing the swash plate surface 44 over a range of up to 2.7 Nin).

Therefore, the charge pump (not shown) is driven to pump the hydraulic oil into the shaft hole 99, and the retainer 83 is gradually moved from the first operating position to the second operating position to change the output rotational speed Nout. The output speed Nout can be controlled more accurately than when it is performed.

(2) The continuously variable transmission 20 of this embodiment is
When the flow of the hydraulic oil in the hydraulic closed circuit C is stopped, the rotation speed of the yoke 23 is maintained even if the retainer 83 is displaced to either the first operating position or the second operating position. . Therefore, as shown in FIG. 12, the output speed Nou
When t is Nin, the output speed Nout is changed from Nin to 2.7N.
First retainer 83 in preparation for increasing to in
Move from the operating position to the second operating position, output rotation speed Nout
Can be kept at Nin.

(3) The continuously variable transmission 20 of this embodiment is
When the retainer 83 is located at the second working position and the fixing position of the retainer 83 is located at the first working position and the second working position, when the retainer 83 is located at the first working position, The rotation speed is increased. Further, when the retainer 83 is in the first operating position, the stroke volume VM becomes VMmax (-VMmax), and when the retainer 83 is in the second operating position, the stroke volume VM is 0.6VMmax. It was set to (-0.6VMmax). The swash plate surface 44 of the cradle 45 is interlocked with the displacement of the retainer 83 from the first operating position to the second operating position.
Is configured to be displaceable.

Therefore, when the output speed Nout is 0, the stroke volume VM of the second hydraulic device 200 is changed from -VMmax by displacing the swash plate surface 44 from the positive maximum tilting angle position to the specific position. The output rotation speed Nout can be kept at 0 by changing to -0.6VMmax.

(Second Embodiment) Next, the second embodiment will be described with reference to FIG.
This will be described with reference to FIGS. It should be noted that the description will focus on the configuration different from that of the first embodiment. Therefore, the components used in the configuration of the first embodiment will be described with the same reference numerals. For the same configuration as that of the first embodiment, refer to the drawings of the first embodiment.

In the second embodiment, in the constitution of the first embodiment,
At the bottom of each plunger hole 57, the cylinder block 42
Is different from the cylinder block 42 in that a cylindrical cover member 131 is slidably fitted in the outer peripheral surface of the cylinder block 42 along the axial direction. .

More specifically, on the outer peripheral surface of the central portion of the cylinder block 42, a ridge 132 is formed at one end in the axial direction, and a locking ring 133 is fixed at the other end. A coil spring 134 as a biasing means is wound around the outer periphery of the central portion of the cylinder block 42 between the cover member 131 and the locking ring 133, and locks the cover member 131 to the ridge 132. Is urged to. The opening hole 130 is closed by the cover member 131 when the cover member 131 is locked to the protrusion 132, and is opened when the cover member 131 is moved to the output end side of the input shaft 21. The hole 130 can be opened to the outside.

A circumferential flange 135 is provided on the outer peripheral surface of the cover member 131 in a protruding manner. The actuating member 136 is inserted into the case 26 via an operation hole 27 a provided in the tubular member 27 of the case 26. The operating member 136 is
A roller 137 that is rotatable around its own axis is provided at the tip, and is in contact with the flange 135 of the cover member 131 via the roller 137. Then, the cover member 131 is driven to the output end side of the input shaft 21 via the flange 135 while resisting the urging force of the coil spring 134 by an actuator (not shown) or the like. When the shift lever 146 is operated to shift to the reverse drive side, the actuator is operated for a predetermined time by a control signal from a control device (not shown) to cause the operating member 136 to move the cover member 131 to the output end side of the input shaft 21. After a lapse of a predetermined time, the control signal disappears and the drive is released.

The cover member 131, the operating member 136, the coil spring 134 and the like constitute an oil removing mechanism M. In addition, in the present embodiment, the output gear 24 is omitted, and instead, the yoke 23 as the output rotating unit is provided with the output gear 24 shown in FIG.
As shown in FIG. 7, a gear shift device 138 (CST) as a forward / reverse rotation switching device is connected. The gear shift device 138 includes a first clutch 139 and a second clutch 140. In the first clutch 139, when the driven clutch plate is connected to the drive side clutch plate connected to the yoke 23, the gear 141 connected to the driven clutch plate is driven to the final reduction gear device (not shown) via the gear 142. Transmits torque. Also, the second clutch 14
0 means that when the driven clutch plate is connected to the drive side clutch plate connected to the yoke 23, the gear 14
3, idler gears 144 and 145, and idler gear 1
The drive torque is transmitted to the final reduction gear device (not shown) via the gear 142 meshed with 45.

That is, it is linked to the operation of the shift lever 146 (see FIG. 20). Based on this operation, the first clutch 139 is engaged when moving forward, and the second clutch 140 is engaged when moving backward.

The plunger hole 57 has a hydraulic closed circuit C.
Form part of the. (Operation) Next, the continuously variable transmission 2 configured as described above.
The action of 0 will be described.

In the second embodiment, the output speed Nou
t refers to the rotation speed of the gear 142. (When the output speed Nout is Nin) The oil draining mechanism M
It is assumed that the cover member 131 constituting the above is locked to the ridge 132 and the opening hole 130 is closed by the cover member 131.

As shown in FIG. 20, the shift lever 146 is operated to position the swash plate surface 44 at the upright position via the cradle 45. In this state, for the same reason as in the first embodiment, the cylinder block 42 and the rotary slope 51 are directly connected to each other and rotate integrally. That is, in this state, the input shaft 21 and the output gear 142 are directly connected.
The rotation imparted to the rotation slope 51 is generated by the yoke 23, the first clutch 139 connected thereto, the gear 141, and the gear 142.
Is transmitted to the final reduction gear transmission via. Also, from here onward in the second embodiment, unlike the first embodiment, N
When the gear 142 rotates in the opposite direction to in, it is called forward rotation.

When the swash plate surface 44 is located at the upright position, the stroke volume VP of the first hydraulic system 100 becomes 0 and the output speed Nout (output gear 2
The rotation speed of 4) is the input rotation speed Nin.

(When the output speed Nout exceeds Nin)
Even in this case, for the same reason as in the first embodiment,
By combining (sum) the number of rotations Nin at which the cylinder block 42 is driven via the input shaft 21 and the number of rotations in the positive direction due to the protrusion pressing action of the plunger 58 on the rotation slope 51,
The rotating slope 51 is rotated. The forward rotation applied to the rotary slope 51 is transmitted as the forward rotation to the final reduction gear through the yoke 23, the connected first clutch 139, the gear 141, and the gear 142 to perform the speed-up action. .

At this time, when the swash plate surface 44 is displaced from the upright position to the side of the predetermined negative tilting angle position, the stroke volume VP of the first hydraulic system 100 increases from 0 to VMmax in FIG. Output rotation speed Nout from Nin is 2.
Speed up to 7 Nin.

The output speed Nout is 2.7 from Nin.
Stroke volume V of the second hydraulic device 200 when changing to Nin
M remains at 0.6 VMmax. The flow and rotation of the hydraulic oil in this state are shown in FIG. In addition,
In this embodiment, in this state, the oil draining portion 110 is closed.

(When the output rotational 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, and a predetermined positive tilt angle from the upright position. Position in the area of position. Note that, out of the positive tilting angle positions, the predetermined positive tilting angle position means that the absolute value of the stroke volume VP of the first hydraulic device 100 is the second hydraulic device 2.
It is a position until it becomes equal to the absolute value of the stroke volume VM of 00.

In this case, for the same reason as in the first embodiment, due to the projecting pressing action of the plunger 58 against the rotating slope 51, the direction opposite to that in the case where the output rotational speed Nout is between Nin and 2Nin or exceeds 2Nin is reversed. Give the rotation of. 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 positive direction which is decreased by the rotational speed in the reverse direction, the output rotational speed Nou
The value t becomes smaller than that in the case where the output speed Nout is Nin.

In this embodiment, at this time, when the swash plate surface 44 is displaced from the upright position to the side of the predetermined positive tilt angle position, the stroke volume VP of the first hydraulic system 100 in FIG.
Increases from 0 to the side of −VMmax, and the output speed Nout decelerates from Nin to 0 accordingly.

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. In this state, a small amount of hydraulic oil flows from the second oil chamber 62 (that is, the hydraulic closed circuit C) to the shaft hole 99 via the oil draining portion 110 and the like as described above.
To the small-diameter portion 113, and some loss occurs. However, the amount of hydraulic oil flowing out is small, and the pressure on the second oil chamber 62 (oil chamber B) side is lower than that on the first oil chamber 61 (oil chamber A) side, so that the yoke 23 is accelerated. There is no problem because the operating efficiency of the plunger 58 that is pressed against is not reduced.

FIG. 18 is a schematic diagram of the state at this time. The first oil chamber 61 (oil chamber A) side is on 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 is as shown by the arrow in the figure.

(When the output speed Nout is 0) Next, the shift lever 146 is operated to position the swash plate surface 44 at the predetermined positive tilt angle position via the cradle 45.

In this case, in this embodiment, the first hydraulic device 1
The stroke volume VP of 00 is -VMmax. As a result, -V
Since P≈−VMmax, the rotational speed in the opposite direction is balanced with the rotational speed Nin at which the cylinder block 42 is driven via the input shaft 21, that is, the sum of the rotational speeds is 0 (the output rotational speed Nout is 0). ), And the output gear 24 stops.

In this state, when the swash plate surface 44 is further tilted to the positive side from the predetermined positive tilt angle position via the cradle 45, the stroke volume V of the first hydraulic system 100 is increased.
The absolute value of P is the stroke volume VM (=
It falls within a range that is larger than the absolute value of (VMmax).

Therefore, the stroke volume V of the second hydraulic system 200 is relative to the absolute value of the stroke volume VP of the first hydraulic system 100.
Since the absolute value of M is relatively small, it should be the second
In the hydraulic system 200, in order to compensate for this, the second hydraulic system 20
The reciprocating speed of the zero plunger 58 should be increased.

However, at this time, the second oil chamber 62 is at a higher pressure side than the first oil chamber 61 side, and the working oil is discharged from the second oil chamber 62 (that is, the hydraulic closed circuit C) to the oil draining portion 110 and the like. Since the high-pressure hydraulic oil flows out to the small diameter portion 113 of the shaft hole 99 via the, the amount of hydraulic oil flowing out increases. When the maximum loss amount flowing out from the hydraulic closed circuit C when the cylinder block 42 makes one rotation is L, the absolute value of the stroke volume VP of the first hydraulic apparatus 100 and the absolute value of the stroke volume VM of the second hydraulic apparatus 200 While the difference (| VP | − | VM |) satisfies | VP | − | VM | ≦ L (= Δ1), as a result, | VP | and | VM |
Since the + loss amount is balanced, in the second hydraulic device 200, the rotation speed in the reverse direction and the cylinder block 42 continue.
Is balanced with the rotational speed Nin driven via the input shaft 21, that is, the sum of the rotational speeds becomes 0 (the output rotational speed Nout is 0), and the output gear 24 maintains the stopped state (neutral).

In FIG. 21, Δ1 is | VP | − | VM
| Indicates the stroke volume difference between both devices from 0 to L. In addition, in FIG. 21, the part of Δ1 is enlarged and illustrated for convenience of description.

(When the output speed Nout is less than 0) Further, in this state, when the shift lever 146 is shifted to the reverse drive side, in response to the operation of the shift lever 146,
An actuator (solenoid) not shown operates for a predetermined time to drive the operating member 136 to the cover member 131 to the output end side of the input shaft 21.

As a result, the opening hole 130 is opened to the outside by the movement of the cover member 131, so that the hydraulic pressure of the hydraulic oil in the plunger hole 57 of the second hydraulic device 200 is released. Further, when this hydraulic pressure is released, 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 first clutch 139 of the gear shift device 138 can be disengaged, so that the second clutch 140 is engaged in conjunction with the operation of the shift lever 146. The hydraulic pressure of the hydraulic oil in the plunger hole 57 is released for the same reason when returning to the forward side.

After the lapse of the predetermined time, the driving of the actuator is released, so that the cover member 131 is moved by the urging force of the coil spring 134 until it is locked by the protrusion 132, and the opening hole 130 is again opened. Block. As a result, the hydraulic pressure of the hydraulic oil acts on the plunger hole 57, and the plunger 58 starts to press against the rotating slope 51.

(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. 21, the output speed Nout and the first hydraulic system 100 are changed. The change state of the stroke volume is the same as in the case of forward movement (normal rotation) and is the same as the case of “when the output rotation speed Nout is between 0 and Nin”, and therefore the description thereof is omitted. FIG. 18 shows the flow and rotation direction of the hydraulic oil.

(When the output rotational speed Nout is between -Nin and -2Nin) The shift lever 146 is operated to tilt the swash plate surface 44 to the negative side through the cradle 45 as in the first embodiment. It is located 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 rotational speed Nin at which the cylinder block 42 is driven through the input shaft 21 and the rotational speed in the same direction due to the projecting pressing action of the plunger 58 on the rotary slope 51 are combined (summed). The rotary slope 51 is rotated. The rotation imparted to the rotation slope 51 is generated by the yoke 2
3, connected second clutch 140, gear 143, idler gear 144, idler gear 145, and gear 14
It is transmitted as a reverse rotation to the final reduction gear transmission via 2.

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. The output speed Nout is from -Nin to-
Speed up to 2Nin.

The output speed Nout is -Nin to -2.
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.

In this state, as in the above, the oil drain portion 110
Through the second oil chamber 62 (that is,
It flows out from the hydraulic closed circuit C) to the small diameter portion 113 of the shaft hole 99, causing some loss. However, the amount of hydraulic oil flowing out is small, and the second oil chamber 62 (oil chamber B) side is
Since the pressure is lower than that on the oil chamber 61 (oil chamber A) side, and the operating efficiency of the plunger 58 that presses the yoke 23 for speeding up is not reduced, there is no problem.

According to this embodiment, the same effects as (1) and (2) of the first embodiment can be obtained, and the following effects can be obtained. (1) In the present embodiment, when the rotation direction of the yoke 23 (output rotation unit) is switched (forward → reverse and reverse → forward), the second
An oil draining mechanism M that operates to release the hydraulic pressure applied to the plunger 58 of the hydraulic device 200 is provided.

As a result, the torque when the rotation direction of the yoke 23 is switched (forward → reverse and reverse → forward) can be released, and the forward / reverse rotation can be easily switched. In particular, in the present embodiment, the plunger hole 57 is directly opened to the outside of the cylinder block 42, so that the above effect can be easily realized.

(2) In this embodiment, the continuously variable transmission 2
0 is configured to include an input shaft 21 that obtains input rotation from the engine 22 (motor), and the input shaft 21 is extended to the non-motor side to configure an output shaft. And
A yoke 23 (output rotating part) is provided on the outer circumference of the extended input shaft 21.
A gear shift device 138 (forward / reverse rotation switching device) capable of transmitting power to the yoke 23 and switching forward / reverse rotation.
To provide a power transmission device.

As a result, the second power transmission device is used.
The function and effect (1) in the embodiment can be achieved. (Third Embodiment) Next, a third embodiment will be described.

In this embodiment, the cylinder block 42 is shared by the first hydraulic device and the second hydraulic device, and the plungers 43 and 58 are arranged radially (hereinafter referred to as a radial type) as a hydraulic continuously variable transmission. This is embodied in the continuously variable transmission 20.

Hereinafter, a brief description will be given with reference to FIGS. FIG. 23 shows a radial type hydraulic continuously variable transmission. In addition, about the same structure as the structure of the said 1st Embodiment, or the structure equivalent, the same code | symbol is attached | subjected, the description is abbreviate | omitted and it demonstrates focusing on a different part.

(First Hydraulic System 100) In the cylinder block 42, the input side end of the input shaft 21 is rotatably supported on the inner peripheral surface of the case 26 via a bearing 161 and the output side end is. It is rotatably connected to the inner peripheral surface of the output rotary cylinder 23A via a bearing 162. The output rotary cylinder 23A is rotatably supported by the side wall member 31 via a bearing 170. The output rotary cylinder 2
3A has a function equivalent to the yoke 23 of other embodiments.

In the radial type first hydraulic device 100, the plurality of plungers 43 are arranged so as to project radially in the cylinder block 42 about the axis O (see FIG. 24).

The outer peripheral surface of the ring-shaped member 165 is formed in a circular cross section (a cross section when cut in a direction orthogonal to the axis O), and the ring-shaped member 165 is formed around its own axis with respect to the inner surface of the case 26. It is rotatably fitted in a sliding contact state. That is, the axis (center) of the outer peripheral surface 165s of the ring-shaped member 165 is arranged coaxially with the axis S of the inner peripheral surface fitted to the case 26.

The inner peripheral surface 165r of the ring-shaped member 165 is
It is formed in a circular cross section, and its axis R (center) is eccentrically arranged with respect to the axis (center) of the outer peripheral surface. That is, the axis R is arranged eccentrically with respect to the axis S.

The ring-shaped member 165 corresponds to the contact portion. Then, as shown in FIG. 24, the ring-shaped member 165.
Is rotatable in a predetermined range including a position where the inner peripheral surface axis R coincides with the axis O (hereinafter referred to as a neutral position). That is, the ring-shaped member 165 is based on the neutral position,
A position rotated by a predetermined angle in the clockwise direction as shown in FIG. 25 (hereinafter, this position is referred to as a first position in this embodiment) and a position rotated by a predetermined angle in the counterclockwise direction as shown in FIG. A position (hereinafter, this position is referred to as a second position in the present embodiment) can be rotated. The rotation of the input shaft 21 is assumed to rotate counterclockwise in FIG. The ring-shaped member 165 reciprocates between the first position and the second position by driving a hydraulic device 178 installed in the case 26 via a connecting shaft 177.

In this embodiment, the position when the ring-shaped member 165 is rotated in the clockwise direction is set to the negative rotation position (see FIG. 25) when the ring-shaped member 165 is located in the neutral position, and the counterclockwise direction is set. The rotation is called the positive rotation position (see FIG. 26).

In this embodiment, the output speed Nout is output.
= Nin, it moves to the negative rotation position when Nout> Nin, and moves to the positive rotation position when Nout <Nin. The output rotation speed is the rotation speed of the output rotary cylinder 23A.

Note that FIG. 25 shows a state in which the ring-shaped member 165 is located at the first position, that is, at the maximum rotational position of the negative rotational position. Further, FIG. 26 shows a state in which the ring-shaped member 165 is located at the second position, that is, at the maximum rotational position of the positive rotational position.

In the portion of the cylinder block 42 facing the ring-shaped member 165, a plurality of plunger holes 47 are arranged radially around the center of rotation (axis O) and at equal angular intervals. The plunger hole 47 has an opening formed on the outer peripheral surface of the cylinder block 42. The plunger 43 is slidably arranged in each of the plunger holes 47 so as to project from the opening.

The ring-shaped member 165 located at the positive rotation position or the negative rotation position causes the plunger 43 to reciprocate in accordance with the rotation of the cylinder block 42, and provides the action of the suction and discharge strokes. As a result, the first
In the hydraulic device 100, for example, the plunger 43 is similarly projected and inserted when the swash plate surface 44 of the first embodiment or the second embodiment is tilted in the positive or negative direction.

(Second hydraulic system 200) Radial type second
The hydraulic device 200 includes a cylinder block 42 and a plurality of plungers 5 slidably arranged on the cylinder block 42.
8, and a plurality of plungers 58 including a cylindrical output rotary cylinder 23A having a sliding contact member 171 that abuts against the plunger 58.
It is arranged so that it can be inserted in the radial direction centering around. As shown in FIG. 27, the sliding contact member 171 is formed in a circular ring shape so that the inner and outer peripheral surfaces thereof are coaxial, and is fitted and fixed to the inner peripheral surface of the inner end of the output rotary cylinder 23A. Sliding member 171
The inner peripheral surface is formed in a circular cross section, and its center is arranged so as to coincide with the center Q of the inner peripheral surface fitted to the output rotary cylinder 23A.

Therefore, the axis (center Q) of the sliding contact member 171 is offset by a predetermined amount Δa from the axis O of the input shaft 21.
Is arranged so as to be eccentric with the output rotary cylinder 2
When 3A rotates, the center Q moves in a circle around the axis O.

In the portion of the cylinder block 42 facing the sliding contact member 171, a plurality of plunger holes 57 are arranged radially at equal angular intervals with respect to the center of rotation (axis O). Same plunger hole 57
Has an opening formed in the outer peripheral surface of the cylinder block 42. Each plunger hole 57 has a plunger 58.
Are slidably arranged so as to project from the opening.

The sliding contact member 171 and the cylinder block 4
At the time of relative rotation with respect to 2, the plunger 58 abuts against the sliding contact member 171 and the plunger 58 reciprocates to repeat the suction and discharge strokes.

Further, in the present embodiment, as in the first embodiment, the maximum stroke volume VPmax of the first hydraulic device 100 is formed to be substantially the same as the maximum stroke volume VMmax of the second hydraulic device 200. . However, strictly speaking, it is slightly VPmax
Is larger and has a difference Δ1. Specifically, the first
The inner diameter of the plunger hole 47 of the hydraulic device 100 is substantially the same as the inner diameter of the plunger hole 57 of the second hydraulic device 200,
Moreover, the maximum rotation position of the ring-shaped member 165 is set so that the diameters of the plungers 43 and 58 are substantially the same and the stroke amounts of the plungers 43 and 58 have a difference in the maximum stroke volume. is doing.

Further, in this embodiment, the first switching valve 66 is
Coil spring 175 arranged at the bottom of the first valve hole 63
Thus, the ball bearing 69 as a bearing is pressed against the inner ring. The ball bearing 69 has its axis centered first.
Similar to the embodiment, they are arranged so as to be oblique to the axis O. The output side end of the second switching valve 76 is pressed against the inner ring 84a of the ball bearing 84 as a bearing by the coil spring 176 arranged at the bottom of the second valve hole 64.

The ball bearing 84 is arranged so that its axis intersects the axis O at an angle. In the present embodiment, the holder 79, the ball bearing 80, and the support member 81 constitute a “member that moves to the cylinder block side”.
In the present embodiment, the ball bearing 84 corresponds to a member that reciprocates the distribution valve. In the present embodiment, the ball bearing 84 is omitted,
The shaft hole housing member 116, the operating pin 128, the holder 7
The displacement mechanism D is composed of 9, the ball bearing 80, and the support member 81. Also in this embodiment, the displacement mechanism D is arranged so as to be located within the outer diameter frame of the cylinder block 42.

Further, in this embodiment, the support member 81 is slidably engaged with the inner peripheral surface of the output rotary cylinder 23A along the guide groove 23c formed parallel to the axis O. Further, the holder 79, which is connected to the support member 81 via the ball bearing 80, has an axial center O with respect to the outer circumference of the input shaft 21.
Is slidably fitted along.

Further, between the cylinder block 42 and the holder 79, a coil spring 126 as an urging means wound around the outer peripheral surface of the input shaft 21 is arranged, and the urging force of the coil spring 126 causes the holder 79 to receive an input. It is constantly urged toward the output end of the shaft 21.

In this embodiment, with the same configuration as that of the first embodiment, the gradient in the tapered portion 118a of the shaft hole accommodating member 116 is formed more gently than the gradient in the tapered groove 129 of the holder 79. Therefore, the amount by which the shaft hole housing member 116 is displaced (first displacement amount) and the ball bearing 84
Is the amount of displacement (second displacement amount).
The amount of displacement is large.

(Operation) The operation of the continuously variable transmission 20 configured as described above will be described with reference to FIGS. 8 to 13 of the first embodiment.

For convenience of explanation, it is assumed that the input rotation speed Nin applied from the crankshaft of the engine 22 to the input shaft 21 is constant. (When the output speed Nout is Nin) The shift lever (not shown) is operated to position the ring-shaped member 165 at the neutral position via the hydraulic device 178.

In this state, for the same reason as in the first embodiment, the cylinder block 42 and the sliding contact member 171 (the output rotary cylinder 23A) are directly connected and rotate integrally.
When the ring-shaped member 165 is located at the neutral position, the stroke volume VP of the first hydraulic device 100 becomes 0, and the output rotation speed Nout (the rotation speed of the output gear 24) is input as shown in FIG. The rotation speed becomes Nin.

(When the output speed Nout exceeds Nin)
First, with the ring-shaped member 165 in the neutral position, that is, with the hydraulic oil in the hydraulic closed circuit C not circulating, the charge pump (not shown) is driven to drive the shaft hole 9
The hydraulic oil in 9 is pressurized.

Then, the shaft hole accommodating member 116 moves to the output end side of the input shaft 21 against the urging force of the coil spring 124, and closes the opening end of the oil passage 112 on the throttle portion 112a side.

Further, the movement of the shaft hole accommodating member 116 toward the output end of the input shaft 21 causes the operating pin 128 to move toward the taper portion 11.
It is pressed by 8a and moves in the radial direction from the axis O of the input shaft 21. The actuating pin 128 is displaced to the distal end with the proximal end of the bottom surface of the tapered groove 129 of the holder 79 being the starting position of the pressing point.

Therefore, the holder 79 moves to the input end side of the input shaft 21 against the urging force of the coil spring 126 by the pressing of the operating pin 128. As a result, when the actuating pin 128 abuts on the distal end of the bottom surface of the tapered groove 129,
The retainer 83 moves from the first operating position to the second operating position, and the displacement end of the second switching valve 76 switches from the first displacement position R1 to the second displacement position R2.

Then, the section communicating with the port W and the second oil chamber 62 becomes narrower, and the section communicating with the port W and the first oil chamber 61 becomes wider. That is, the area J is exceeded when Nin is exceeded.
Becomes wider and the region K becomes narrower as shown in FIG. As a result, as shown in FIG. 13B, the amount of hydraulic oil per stroke that flows from the plunger hole 57 to the second oil chamber 62 through the port W is from the first oil chamber 61 to the port W.
It becomes less than the amount of hydraulic oil per stroke that flows into the plunger hole 57 through.

Therefore, the second oil chamber 6 of the second hydraulic device 200
The stroke volume communicating with 2 is 0.6VMmax. By operating a shift lever (not shown), the ring-shaped member 165 is rotated via the hydraulic device 178 and is positioned in the region of the negative rotation position between the neutral position and the first position.

In this case as well, for the same reason as in the first embodiment, the rotational speed Nin at which the cylinder block 42 is driven via the input shaft 21 and the forward direction due to the protrusion pressing action of the plunger 58 on the sliding contact member 171 are set. The sliding contact member 171 (the output rotary cylinder 23A) is rotated by the combination (sum) with the rotation speed of. The forward rotation imparted to the sliding contact member 171 is transmitted as the forward rotation to the final reduction gear transmission through the output rotary cylinder 23A, the output gear 24 and the like, and the speed increasing action is performed.

At this time, when the ring-shaped member 165 is displaced from the neutral position to the negative rotation position, in FIG.
The stroke volume VP of the first hydraulic system 100 increases from 0 to VMmax, and the output speed Nout is accordingly increased from Nin to 2.
Speed up to 7 Nin.

The output speed Nout is 2.7 from Nin.
Stroke volume V of the second hydraulic device 200 when changing to Nin
M remains at 0.6 VMmax. The flow and rotation of the hydraulic oil in this state are shown in FIG. In this embodiment, in this state, the oil drain portion 110 is closed.

Conversely, Nout changes from Nout> Nin to Nout <
When changing to Nin, the displacement end of the second switching valve 76 is
When the displacement position R2 is switched to the first displacement position R1, 0.
From 6VMmax to -VMmax.

(When the output rotational speed Nout is between 0 and Nin) In this state, the shaft hole housing member 116 is urged by the coil spring 124.
Is always locked to the locking step portion 114a, a small amount of hydraulic oil flows from the second oil chamber 62 (that is, the hydraulic closed circuit C) to the small diameter of the shaft hole 99 via the oil draining portion 110 and the hole 120. It is allowed to flow out to the portion 113. That is, the displacement end of the second switching valve 76 is located at the first displacement position R1.

A shift lever (not shown) is operated and actuated via the hydraulic device 178 to position the ring-shaped member 165 in the region of the rotational position on the positive side from the neutral position. In this case, for the same reason as in the first embodiment, due to the projecting pressing action of the plunger 58 on the sliding contact member 171, the rotation in the opposite direction to the above-mentioned "when the output rotation speed Nout is between Nin and 2Nin and over 2Nin" is caused. give. Therefore, the output rotary cylinder 23A and the output gear 24 are rotated by combining (summing) the reverse rotation speed and the forward rotation speed of the cylinder block 42.

Since the sum of the rotation speeds at this time becomes the rotation speed in the forward direction which is decreased by the rotation speed in the reverse direction, the output rotation speed Nou
The value t becomes smaller than that in the case where the output speed Nout is Nin.

In this embodiment, when the ring-shaped member 165 is displaced from the neutral position to the second position at this time, as shown in FIG.
2, the stroke volume VP of the first hydraulic system 100 increases from 0 to the −VMmax side, and the output rotation speed Nout accordingly.
Decelerates 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. In this state, a small amount of hydraulic oil flows from the second oil chamber 62 (that is, the hydraulic closed circuit C) to the shaft hole 99 via the oil draining portion 110 and the like as described above.
To the small-diameter portion 113, and some loss occurs. However, the amount of hydraulic oil flowing out is small, and the pressure on the second oil chamber 62 (oil chamber B) side is lower than that on the first oil chamber 61 (oil chamber A) side, and the output rotary cylinder 23A is accelerated. There is no problem because the operating efficiency of the plunger 58, which is pressed for this purpose, is not reduced. FIG. 10 is a schematic diagram of the state at this time.

(When the output rotation speed Nout is 0) Next, the shift lever (not shown) is operated to rotate the ring-shaped member 165 via the hydraulic device 178, and the ring-shaped member 165 is rotated.
To the second position.

In this case, in this embodiment, the first hydraulic device 1
The stroke volume VP of 00 is -VMmax. As a result, -V
Since P≈−VMmax, the rotational speed in the opposite direction is balanced with the rotational speed Nin at which the cylinder block 42 is driven via the input shaft 21, that is, the sum of the rotational speeds is 0 (the output rotational speed Nout is 0). ), And the output gear 24 stops.

In this state, when the ring-shaped member 165 is further rotated through the hydraulic device 178 and further rotated from the second position to the positive side, the absolute value of the stroke volume VP of the first hydraulic device 100 becomes Stroke volume VM of the second hydraulic device 200
It enters the range where it becomes larger than the absolute value of (= VMmax).

Therefore, the stroke volume V of the second hydraulic system 200 is relative to the absolute value of the stroke volume VP of the first hydraulic system 100.
Since the absolute value of M is relatively small, it should be the second
In the hydraulic system 200, in order to compensate for this, the second hydraulic system 20
The reciprocating speed of the zero plunger 58 should be increased.

However, at this time, the second oil chamber 62 is at a higher pressure side than the first oil chamber 61 side, and the working oil is discharged from the second oil chamber 62 (that is, the hydraulic closed circuit C) to the oil draining portion 110 or the like. The high-pressure hydraulic oil flows out to the small diameter portion 113 of the shaft hole 99 via the.

Letting L be the maximum loss amount flowing out from the hydraulic closed circuit C when the cylinder block 42 makes one rotation,
As in the embodiment, the stroke volume VP of the first hydraulic device 100
While the difference (| VP | − | VM |) between the absolute value of | and the absolute value of the stroke volume VM of the second hydraulic device 200 satisfies | VP | − | VM | ≦ L (= Δ1) , | VP | and | VM | + the amount of loss are balanced, so in the second hydraulic device 200, the rotation speed in the reverse direction and the cylinder block 42 continue to be applied to the input shaft 21.
Is balanced with the rotational speed Nin driven through, that is, the total rotational speed is 0 (output rotational speed Nout is 0),
The output gear 24 maintains the stopped state (neutral).

In FIG. 12, Δ1 is | VP | − | VM
| Indicates the stroke volume difference between both devices from 0 to L. (When the output rotation speed Nout is less than 0) First, the stroke volume VP of the first hydraulic device 100 is changed from the second position to the ring-shaped member 165 while the output rotation speed Nout remains 0.
A process of displacing the position to 0.6 VMmax (hereinafter, referred to as a specific position) is performed. When this process is performed, the ring-shaped member 165 is displaced from the second position to the specific position, and at the same time, the stroke volume VM of the second hydraulic device 200 is moved.
Is changed from -VMmax to -0.6VMmax to keep the output rotation speed Nout at 0.

When the stroke volume VM of the second hydraulic system 200 is changed from -VMmax to -0.6VMmax, it is not shown, as described in "When the output speed Nout exceeds Nin". By driving the charge pump to pressurize the hydraulic oil into the shaft hole 99, the second switching valve 76 is moved from the first displacement position R1 to the second displacement position R2. At this time, the retainer 83 is moved from the first operating position to the second operating position. Further, in this state, the oil draining portion 110 is closed.

Therefore, as shown in FIG. 13B, the section communicating with the port W and the second oil chamber 62 becomes narrow, and the port W
And a section communicating with the first oil chamber 61 becomes wider. As a result, the stroke volume communicating with the second oil chamber 62 of the second hydraulic device 200 becomes 0.6VMmax.

Then, when the output speed Nout is set to less than 0, the following is performed. A shift lever (not shown) is operated and actuated via the hydraulic device 178 to position the ring-shaped member 165 in the region of the rotation position on the positive side from the specific position.

Further, the stroke volume VP of the first hydraulic system 100
Is the stroke volume VM (= 0.6VMm of the second hydraulic device 200).
Range larger than ax) (0.6VMmax <VP ≦ VMm
ax).

As a result, the stroke volume VM of the second hydraulic device 200 becomes relatively smaller than the stroke volume VP of the first hydraulic device 100. Therefore, in the second hydraulic device 200, the second hydraulic device 200 compensates for this. The reciprocating speed of the 200 plunger 58 is increased.

In this case, for the same reason as in the first embodiment, the projecting pressing action of the plunger 58 against the sliding contact member 171 is opposite to the above-mentioned "when the output rotational speed Nout is between Nin and 2Nin and exceeds 2Nin". Gives rotation in a direction. Therefore, depending on the rotation speed in the opposite direction, the output rotary cylinder 23A,
The output gear 24 is rotated. The rotation speed at this time becomes smaller than that when the output rotation speed Nout is zero.

When the ring-shaped member 165 is displaced from the specific position toward the second position, the first hydraulic device 1 shown in FIG.
The stroke volume VP of 00 increases from -0.6VPmax to -VPmax, and accordingly, the output speed Nout is 0 to approximately-.
Decelerate to 0.7 Nin. FIG. 11 is a schematic diagram of the state at this time.

According to the third embodiment, the same effects as (1) to (3) of the first embodiment can be obtained. The embodiments of the present invention are not limited to the above-described embodiments, but may be carried out as follows.

(1) The structure of the gear shift device 138 in the structure of the second embodiment is shown in FIG.
Change to a configuration of 0 (CST). Gear shift device 15
As shown in the figure, 0 includes a forward clutch 152 and a reverse clutch 153, which are connected to an output shaft 155 that transmits a driving torque to a final reduction gear device (not shown). The following gear train is attached.

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, a driving torque is applied to a final reduction gear (not shown) via the output rotary cylinder 23A, the output gear 24, the gear 151, the forward clutch 152, and the output shaft 155. introduce.

Also, the output gear 24 is provided with 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 shift lever 1
When the reverse clutch 153 is engaged by the reverse operation of 46, the drive 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 forward / reverse rotation switching device. (2) In the second embodiment, the oil draining mechanism M may be omitted and the charge valve 90 shown in FIG. 4 may be used as the oil draining mechanism M instead.

That is, in the case (when the output speed Nout is less than 0), when the shift lever 146 is shifted to the reverse drive side, in response to the operation of the shift lever 146,
The charge pressure of the charge pump is the coil spring 97,
It is less than the biasing force of 98. Then, as shown in FIG. 4, the charge valves 90 and 91 are pressed and locked to the inner bottom portions of the valve housing holes 85 and 86 (in FIG. 4, the charge valves 91 and 91).
Only shows that it has moved. ). Then the first
The hydraulic oil in the oil chamber 61 and the second oil chamber 62 is stored in the valve storage holes 85 and 86.
Is discharged to the outside through the openings 88 and 89 of the.

When this hydraulic pressure is released, the plunger hole 5
Since the hydraulic pressure of the hydraulic oil 7 is released, the pressing action of the plunger 43 on the swash plate surface 44 and the pressing action of the plunger 58 on the rotating slope surface 51 are eliminated. In particular, the output rotary cylinder 23A becomes free from the second hydraulic device 200. Therefore, the first clutch 139 of the gear shift device 138 can be disengaged, so that the shift lever 14
The second clutch 140 is connected in conjunction with the operation of 6. The hydraulic pressure of the hydraulic oil in the plunger hole 57 is released for the same reason when returning to the forward side.

After the lapse of the predetermined time, when the charge pressure is restored by a charge pump (not shown), the charge valves 90 and 91 close the openings 88 and 89. As a result, the hydraulic pressure of the hydraulic oil acts on the plunger holes 47 and 57,
The plunger 43 and the plunger 58 are respectively on the swash plate surface 4.
4 and the rotating slope 51 are started to be pressed. Even in this case, the same effect as that of the second embodiment can be obtained.

[0231]

According to the invention described in claims 1 to 6, the speed control of the output rotation can be easily performed by the displacement of the contact portion over the entire rotation speed range.

According to the second aspect of the invention, the member for reciprocating the distribution valve is moved from the first operating position to the second operating position when the flow of hydraulic oil in the hydraulic closed circuit is stopped. Even if it does, the rotation speed of the output rotation unit can be maintained.

According to the invention described in claims 3 to 5, the hydraulic pressure applied to the plunger of the second hydraulic device is released when the output rotating portion reverses (forward → reverse, reverse → positive). Since the oil draining mechanism that operates in the above is provided, the torque at the time of switching the rotation of the output rotation unit from the normal to the reverse or from the reverse to the positive can be released, and the normal / reverse rotation switching can be easily performed.

According to the invention of claim 6, claim 3
The effects described in any one of claims 5 to 5 can also be realized in the power transmission device.

[Brief description of drawings]

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

FIG. 2 is a transverse cross-sectional view of a cylinder block of the continuously variable transmission, similarly.

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

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

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

FIG. 6 is a sectional view of the same main part.

7A is a perspective view of a retainer 70, and FIG. 7B is an enlarged view of a main part.

FIG. 8 is an explanatory diagram showing the timing when the ports are opened by the first switching valve 66 and the second switching valve 76.

FIG. 9 is a conceptual diagram of the continuously variable transmission according to the first embodiment.

FIG. 10 is a conceptual diagram of a continuously variable transmission that similarly shows the operation of the first embodiment.

FIG. 11 is a conceptual diagram of a continuously variable transmission that also exhibits the same effect.

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

FIG. 13A is an explanatory diagram showing a timing at which a port W opens. (B) is an explanatory view showing the timing when the port W is opened.

FIG. 14 is a plan sectional view of a continuously variable transmission according to a second embodiment.

FIG. 15 is a sectional view of the same main part.

FIG. 16 is a sectional view showing the same operation.

FIG. 17 is a conceptual diagram of a continuously variable transmission according to a second embodiment.

FIG. 18 is a conceptual diagram of a continuously variable transmission.

FIG. 19 is a conceptual diagram of a continuously variable transmission that also exhibits the same effect.

FIG. 20 is a plan view of a shifter.

FIG. 21 is a characteristic diagram showing a stroke volume and an output rotation speed.

FIG. 22 is a conceptual diagram of a main part of another embodiment.

23 is a cross-sectional view of the continuously variable transmission according to the third embodiment and is a cross-sectional view taken along the line AA of FIG.

FIG. 24 is a transverse sectional view of the first hydraulic device.

FIG. 25 is a transverse sectional view showing the same operation.

FIG. 26 is a transverse sectional view showing the same operation.

FIG. 27 is a transverse sectional view of the second hydraulic device.

[Explanation of symbols]

20 ... Hydraulic continuously variable transmission, 21 ... Input shaft, 22 ... Engine as a prime mover, 23 ... Yoke as output rotating part, 42 ... Cylinder block, 43, 58 ... Plunger, 44 ... Swash plate as abutting part Surface (first and second embodiments), 76 ... Second switching valve as distribution valve, 83 ... Retainer (first and second embodiments) as member for reciprocating distribution valve, 84 ... Reciprocation of distribution valve Ball bearings (third embodiment) as moving members, 90 ... Charge valve as an oil removing mechanism, 100 ... First hydraulic device, 138 ... Gear shift device as forward / reverse rotation switching device, 150 ... Forward / reverse rotation switching device Gear shift device as 165, a ring-shaped member as a contact portion (third embodiment), 200 ... second hydraulic device, C
... hydraulic closed circuit, D ... displacement mechanism, M ... oil draining mechanism.

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.

Claims (6)

[Claims] 1. A variable displacement first hydraulic device comprising a plunger, wherein the abutting portion allows the plunger to project and enter.
A second hydraulic device having a plunger and having an output rotating part that performs either relative rotation or synchronous rotation with respect to input rotation by abutting of the plunger is combined, and a cylinder block that houses both plungers is shared, and The cylinder block is configured to rotate in synchronization with the input rotation, a hydraulic closed circuit that connects the first hydraulic device and the second hydraulic device is provided, and reciprocates the inflow and outflow of hydraulic oil between the second hydraulic device and the hydraulic closed circuit. In a hydraulic continuously variable transmission equipped with a distribution valve for switching the distribution valve and displacing a member for reciprocating the distribution valve in the axial direction of the cylinder block, in the axial direction of the member for reciprocating the distribution valve by the displacement mechanism. The fixed position is the first working position and the second working position whose absolute value is smaller than the stroke volume at the time of the first working position, and the member for reciprocating the distribution valve is the first. Operating position or when the holding state of the second working position, the hydraulic stepless transmission in which the contact portion of the first hydraulic device is characterized by being configured to be displaceable. 2. The hydraulic continuously variable transmission includes a member that reciprocates a distribution valve when the flow of hydraulic oil in a hydraulic closed circuit is stopped, in either a first operating position or a second operating position. The hydraulic continuously variable transmission according to claim 1, wherein the rotational speed of the output rotating portion is maintained even when the output rotating portion is displaced to the position. 3. The hydraulic continuously variable transmission according to claim 1, further comprising an oil draining mechanism that operates to release the hydraulic pressure applied to the plunger of the second hydraulic device. . 4. The hydraulic continuously variable transmission according to claim 3, wherein the oil draining mechanism directly releases the closed hydraulic circuit to the outside of the cylinder block. 5. The hydraulic continuously variable transmission according to claim 3, wherein the oil draining mechanism directly releases a plunger hole for slidably accommodating the plunger of the second hydraulic device to the outside of the cylinder block. 6. Any one of claims 3 to 5
The cylinder block of the hydraulic continuously variable transmission described in
With a configuration that is connected to an input shaft that obtains an input rotation from a prime mover, the input shaft is extended to the non-prime mover side and configured as an output shaft, and the output rotating portion is provided on the extended input shaft outer periphery, A power transmission device comprising a forward / reverse rotation switching device capable of transmitting power to the output rotation unit and switching forward / reverse rotation.