JPH1182288A - Swash plate type hydraulic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a swash plate type hydraulic device compact in the radial direction by forming many spool type distribution valves which communicate a port of each cylinder hole with a low pressure oil passage and a high pressure oil passage and change them over alternately and have a small diameter and setting a pitch circle in which the distribution valves are arranged so as to have a smaller diameter than that of a pitch circle in which a plunger is arranged. SOLUTION: A plurality of pump cylinder holes 25 and the same number of motor cylinder holes 39 as the pump cylinder holes 25 are alternately formed on a first pitch circle C1 in a cylinder block 4 spline-connected with an intermediate part of an output shaft supported on both right and left end walls of a mission case which stores a swash plate type continuously variable transmission. Moreover, the same number of second valve holes 40 as the motor cylinder holes 39 are alternately formed with first valve holes 26 on a first pitch circle C2 in which the first valve holes 26 are arranged. A first distribution valve 28 and a second distribution valve 42 are fitted in each valve hole 26, 40, and these distribution valves 28, 42 are formed to have a smaller diameter than those of a pump plunger 27 and a motor plunger 41 fitted in each cylinder hole 25, 39 so as to reduce a diameter of the cylinder block 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a swash plate type hydraulic device used as a swash plate type hydraulic pump or a hydraulic motor.
In particular, a cylinder block having a large number of cylinder holes annularly arranged in parallel with the axis on a first pitch circle surrounding the cylinder block axis and a large number of ports individually connected to the cylinder holes, and sliding in the large number of cylinder holes. A large number of plungers that fit freely, a plunger swash plate that is engaged with tips of the plungers protruding toward one end of the cylinder block, and is arranged to reciprocate the plungers by relative rotation with the cylinder block; A low-pressure oil passage, a high-pressure oil passage, and a circular arrangement arranged in parallel with the axis on a second pitch circle surrounding the axis, and provided in the cylinder block. A large number of spool-type distribution valves that alternately switch the communication between the passage and the high-pressure oil passage, and engage with the tips of these distribution valves protruding toward one end of the cylinder block. With the relative rotation of the cylinder block that these dispensing valve consisting of a valve swash plate for reciprocating ゝ an improvement.

[0002]

2. Description of the Related Art Conventionally, such a swash plate type hydraulic device has been already known as disclosed in Japanese Patent Application Laid-Open No. 63-203959.

[0003]

In such a swash plate type hydraulic device, it is effective to increase the stroke of the plunger in order to reduce the size in the radial direction and increase the capacity. In the hydraulic device disclosed in Japanese Patent Application Laid-Open No. H11-157, the distribution valve group in the annular arrangement is disposed radially outward of the group of plungers in the annular arrangement, so that the distribution valve group prevents the apparatus from being compact in the radial direction.

[0004] The present invention has been made in view of such circumstances, and secures a sufficient stroke of a plunger by arranging a distribution valve group using a dead space inside a plunger group. It is another object of the present invention to provide the swash plate type hydraulic device which can effectively reduce the size in the radial direction.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a plurality of cylinder holes which are arranged in an annular shape in parallel with a cylinder block axis on a pitch circle which surrounds the axis, and are individually connected to the cylinder holes. A cylinder block having a large number of ports, a large number of plungers slidably fitted in the large number of cylinder holes, and engaging with the tips of these plungers protruding toward one end of the cylinder block to rotate relative to the cylinder block. A plunger swash plate arranged to give reciprocating motion to these plungers, a low-pressure oil passage and a high-pressure oil passage, and provided in a cylinder block in an annular arrangement parallel to the axis on a pitch circle surrounding the axis, A large number of spool-type distribution valves which reciprocate in the axial direction to alternately switch the port of each cylinder hole to a low-pressure oil passage and a high-pressure oil passage; A swash plate type hydraulic device, comprising a valve swash plate that engages with a tip protruding toward one end of a cylinder block and reciprocates these distribution valves with relative rotation with respect to the cylinder block. A first feature is that the diameter is formed to be small and the second pitch circle is set to be smaller than the first pitch circle.

According to the first feature, the distribution valve group is arranged in the dead space inside the plunger group in the cylinder block in the radial direction, so that the first pitch circle is set to a sufficient size. Therefore, even if the reciprocating stroke given to the plunger by the plunger swash plate is sufficiently secured, the existence of the distribution valve group does not increase the diameter of the cylinder block, and makes the continuously variable transmission radially compact. Can be. Further, since the distribution valve is formed smaller in diameter than the plunger, the distribution valve group can be easily arranged even inside the plunger group.

[0007] In addition to the above features, the present invention has a second feature in that the valve swash plate is arranged on the same slope as the plunger swash plate and is formed integrally with the plunger swash plate.

According to the second feature, it is possible to suppress an increase in the axial dimension of the hydraulic device due to the plurality of swash plates, and to easily integrate the plunger swash plate and the valve swash plate.

Further, in the present invention, in addition to the second feature, the port of each cylinder hole is controlled to be switched by the distribution valve at a position where the port is shifted by 90 ° in the circumferential direction of the cylinder block with respect to the cylinder hole. The third thing that was formed
The feature of.

According to the third feature, the distribution valve shuts off the port between the low pressure oil passage and the high pressure oil passage at the midpoint of the reciprocating stroke. When the plunger reaches the forward limit or the backward limit, the corresponding port is disconnected from both the low-pressure oil passage and the high-pressure oil passage. Alternatively, when the movement is changed to the forward movement, the communication switching of the port to the low-pressure oil passage or the high-pressure oil passage can be accurately performed.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments of the present invention shown in the accompanying drawings.

First, a first embodiment in which the present invention is applied to a swash plate type continuously variable transmission will be described with reference to FIGS.

1 and 2, an output shaft 2 is supported on left and right end walls of a transmission case 1 accommodating a swash plate type continuously variable transmission T via ball bearings 3, 3. An input member 5 to which an input gear 5 a is fixed adjacent to a left end wall of the transmission case 1 is rotatably supported via an angular contact bearing 6. The power of an engine (not shown) is input to the input gear 5a, and the power is output from the right end of the output shaft 2 to a load (not shown), for example, a drive device of a motorcycle.

The input member 5 is integrally formed with a swash plate holder 8 which is supported on the output shaft 2 via a needle bearing 7, and a first swash plate assembly 9 is mounted on the swash plate holder 8 by a ball bearing. It is rotatably supported via an angular contact bearing 10 and an angular contact bearing 11. The first swash plate assembly 9 includes a pump swash plate 9a (plunger swash plate) and a first valve swash plate 9b surrounded by the pump swash plate 9a and arranged on the same slope.
And the pump swash plate 9a and the first
The swash plate holder 8 is arranged so that the valve swash plate 9b is inclined at a fixed angle with respect to the axis X of the output shaft 2.

A cylinder block 4 concentric with the output shaft 2 is spline-coupled to an intermediate portion of the output shaft 2, and is fixed by a flange 12 and a sleeve 13 on the shaft 2 so as to be immovable in the axial direction.

On the opposite side of the cylinder block 4 from the first swash plate assembly 9, a swash plate anchor 15 fixed to the transmission case 1 with bolts 14 is supported on the output shaft 2 via an angular contact bearing 16. You. A semi-cylindrical trunnion 18 having an axis Y orthogonal to the axis X of the output shaft 2 is rotatably supported on the swash plate anchor 15 within a fixed angle range.
A swash plate assembly 19 is rotatably supported via a ball bearing 20 and an angular contact bearing 21. The second swash plate assembly 19 integrally includes a motor swash plate 19a (plunger swash plate) and a second valve swash plate 19b surrounded by the motor swash plate 19a and arranged on the same slope. The trunnion 18 has an operating arm (not shown) at one end in the axial direction. The trunnion 18 is rotated by the operating arm, so that the output shaft 2 of the motor swash plate 19a and the second valve swash plate 19b has two axes X. The inclination angle with respect to can be changed.

The swash plate anchor 15 has a cylinder block 4
Is rotatably supported via a ball bearing 31 and the cylinder holder 17 is fixed by bolts 38.

A left angular contact bearing 6 disposed on the output shaft 2 and supporting the input member 5 and the first swash plate assembly 9, and a swash plate anchor 15 disposed on the output shaft 2. A pair of annular grooves 2 on the output shaft 2 are provided on each outer surface of the right angular contact bearing 16.
The split cotters 23, 23 engaged with the cotters 2, 22 are arranged so as to come into contact with each other, and a retainer ring 24 is fitted around the outer periphery of each cotter 23. The thrust load generated between the first swash plate assembly 9 and the cylinder block 4 by the operation of the continuously variable transmission T is output from the left and right angular contact bearings 6 and 16 via the left and right cotters 23 and 23. The thrust load generated by the shaft 2 and generated between the swash plate anchor 15 and the cylinder block 4 is supported by the output shaft 2 via the flange 12 and the right cotter 23, thereby reducing the load on the transmission case 1. Can be reduced.

In the cylinder block 4, an odd number (five in the illustrated example) of pump cylinder holes 25 are annularly arranged on a first pitch circle C ₁ (see FIG. 2) concentric with the cylinder block 4. is formed, and is formed by annularly arranged on the pump cylinder bore 25 and the second pitch circle C ₂ concentric thereto under a smaller diameter than the first valve hole 26 is first pitch circle C ₁ of the same number. The pump cylinder hole 25 has one end opened at the left end face of the cylinder block 4 and the other end closed.
The first valve hole 26 has a smaller diameter than the pump cylinder hole 25 and penetrates the cylinder block 4 in the axial direction.

A pump plunger 27 and a spool-type first distribution valve 28 are slidably fitted in the pump cylinder hole 25 and the first valve hole 26, respectively. Each of the pump plunger 27 and the first distribution valve 28 has a tip protruding from the left end surface of the cylinder block 4 to abut on the pump swash plate 9a and the first valve swash plate 9b. Thus, the pump swash plate 9a and the first valve swash plate 9b are
During the rotation, the pump plunger 27 and the first distribution valve 28 are reciprocated in the axial direction. These components constitute a swash plate type hydraulic pump P (swash plate type hydraulic device).

As shown in FIGS. 1 and 5, each tip of the pump plunger 27 and the first distribution valve 28 has a spherical end 29.
a, 30a, and these spherical ends 29a,
30a engage, larger diameter spherical recesses 29b,
30b is formed on the pump swash plate 9a and the first valve swash plate 9b, whereby the pump swash plate 9a and the pump plunger 2 are formed.
7, preventing slippage in the rotation direction between each of the first valve swash plate 9b and the first distribution valve 28, and suppressing the bending moment received by the pump plunger 27 and the first distribution valve 28 from the corresponding swash plate 9a, 9b. Can be reduced.

As shown in FIGS. 1 and 6, the first swash plate assembly 9 includes the spherical ends 29a, 30a of the pump plunger 27 and the first distribution valve 28, respectively, corresponding to the corresponding swash plates 9a, 9b.
An annular retainer plate 32 that is held in engagement with the spherical concave portions 29b and 30b is rotatably attached by a circlip 33. This retainer plate 32 is provided with the same number of plunger holding holes 34 corresponding to the annularly arranged pump plungers 27 and the same number of valve holding holes 35 corresponding to the annularly arranged first distribution valve 28. The plunger holding hole 34 is provided with the spherical end 2 of the pump plunger 27.
A smaller diameter than 9a, and is formed in a larger diameter than the neck 29a ₁ of the spherical end 29a, it is opened to the outer periphery of the retainer plate 32 by the notch 36. The width of the notch 36 is slightly larger than the neck 29a ₁ of the spherical end portion 29a. Thus, the neck 29a of the pump plunger 27 is
After being arranged in the plunger holding hole 34 through the notch 36,
The pump plunger 27 is inserted into the pump cylinder bore 25, also when attaching the retainer plate 32 to the first swash plate assembly 9, it is possible to prevent the disengagement from the notch 36 of the neck 29a _1, plunger retaining holes Spherical end 2 by 34
9a can be held at the position of engagement with the spherical recess 29b. Therefore, the pump plunger 27 can be forcibly reciprocated with the relative rotation of the pump swash plate 9a and the cylinder block 4, so that the pump plunger 27
It is not necessary to provide a return spring for urging the spring in the projecting direction.

The valve holding hole 35 has a diameter smaller than that of the spherical end 30a of the first distribution valve 28 and the neck 3 of the spherical end 30a.
Together formed from 0a ₁ in diameter, it is open to the inner periphery of the retainer plate 32 by the notch 37. The width of the notch 37 is slightly larger than the neck 30a ₁ of the spherical end portion 30a. Therefore, by the same assembling procedure as that of the pump piston 27, the notches of the neck 30a ₁ 37
From the spherical end portion 30a.
Can be held at the engagement position with the spherical concave portion 30b, so that the first distribution valve 28 can be forcibly reciprocated with the relative rotation of the first valve swash plate 9b and the cylinder block 4.

Referring again to FIG. 1 and FIG.
The lock 4 also has the same number of motors as the pump cylinder holes 25.
The cylinder hole 39 is the first pin of the pump cylinder hole 25 group.
H circle C₁And the pump cylinder hole 25
They are formed so as to be aligned with each other, and are the same as the motor cylinder holes 39.
Of the second valve holes 40 are the first pitch circle C of the first valve holes 26 group. _Two
Formed annularly and alternately arranged with the first distribution valve 28.
It is. One end of the motor cylinder hole 39 is a cylinder block.
Open the right end face of the lock 4 and close the other end.
The second valve hole 40 has a smaller diameter than the motor cylinder hole 39.
Formed and penetrates the cylinder block 4 in the axial direction
doing. In the illustrated example, the pump cylinder hole 25 is
The data cylinder hole 39, the first valve hole 26 and the second valve hole 40 are
Each has the same diameter. Therefore, the second valve hole 40
The diameter is smaller than the motor cylinder hole 39.

A motor plunger 41 and a spool-type second distribution valve 42 are slidably fitted in the motor cylinder hole 39 and the second valve hole 40, respectively. Each of the motor plunger 41 and the second distribution valve 42 has a tip protruding from the right end face of the cylinder block 4 and is brought into contact with the motor swash plate 19a and the second valve swash plate 19b. The motor swash plate 19a and the second valve swash plate 19b reciprocate in the axial direction to the motor plunger 41 and the second distribution valve 42 when the cylinder block 4 rotates. A motor M (swash plate type hydraulic device) is configured.

Motor plunger 41 and second distribution valve 42
Are formed at spherical ends 43a, 44a, respectively.
Spherical recesses 43b and 44b having a larger diameter than the spherical end portions 43a and 44a are formed in the motor swash plate 19a and the second valve swash plate 19b.
9a and the motor plunger 41, the second valve swash plate 19b and the second
While preventing slippage in the rotational direction between each of the distribution valves 42,
The bending moment that the motor plunger 41 and the second distribution valve 42 receive from the corresponding swash plates 19a and 19b can be reduced.

The second swash plate assembly 19 includes the spherical end portions 43a, 44a of the motor plunger 41 and the second distribution valve 42.
To the spherical recesses 43b, 4 of the corresponding swash plates 19a, 19b.
An annular retainer plate 45 that is held in an engaged state with the 4b is rotatably attached by a circlip 46. The retainer plate 45, the motor plunger 41 and the second distribution valve 4
2 is the same as the connection structure between the retainer plate 32 and the pump plunger 27 and the first distribution valve 28.

In the cylinder block 4, annular high-pressure oil passages 47 and low-pressure oil passages 48 intersecting with both the first and second valve holes 26 and 40 are formed at intervals in the axial direction. The first valve hole 2 extending from the cylinder hole 25 and out of phase by 90 ° with respect to the counter rotation direction of the cylinder block 4 (the arrow R in FIG. 2 indicates the rotation direction of the cylinder block 4).
6 and a number of motor ports 39a extending from the respective motor cylinder holes 39 and reaching the second valve holes 40 which are out of phase by 90 ° with respect to the anti-rotation direction of the cylinder block 4. You.

As shown in FIG. 8, each first distribution valve 28
The first land portions 28 sequentially arranged from the spherical end portion 29a side
a, a first annular groove 28d, a second land portion 28b, a second annular groove 28e, and a third land portion 28c. In the right movement limit of the first distribution valve 28 by the first valve swash plate 9b, 1
The annular groove 28d communicates between the pump port 25a and the high-pressure oil passage 47, the second land portion 28b blocks between the pump port 25a and the low-pressure oil passage 48, and at the left end thereof, the second annular groove 28e is closed. The pump port 25a and the low-pressure oil passage 48 communicate with each other, and the second land 28b cuts off the connection between the pump port 25a and the high-pressure oil passage 47. At the middle point of the stroke, the first and second land portions 28a,
28b shuts off the pump port 25a from both the oil passages 57 and 58.

On the other hand, as shown in FIG. 9, each second distribution valve 42 has a first land portion 42a, an annular groove 42c, and a second land portion 42b which are sequentially arranged from the spherical end portion 44a side. In the left movement limit of the second distribution valve 42 by the second valve swash plate 19b, the annular groove 42c communicates between the motor port 39a and the low-pressure oil passage 48, and the second land portion 42b connects the motor port 39a and the high-pressure oil passage 47. In the rightmost limit, the annular groove 42c communicates between the motor port 39a and the high-pressure oil passage 47, and the first land portion 42a
Cuts off between the motor port 39a and the low-pressure oil passage 48, and at the midpoint of the stroke, the first and second land portions 42
a and 42b shut off the motor port 39a from both of the oil passages 47 and 48.

As shown in FIG. 1, a supply pump 4 driven by an engine (not shown) is provided at the center of the output shaft 2.
9 is formed, and a first oil supply passage 50 is formed in the output shaft 2 so as to communicate between the supply oil passage 50 and each of the low-pressure oil passage 48 and the high-pressure oil passage 47. Communication hole 51
A first check valve 53 and a second check valve 54 are mounted in the second communication hole 52, respectively. First check valve 5
3 permits the flow of oil only in one direction from the supply oil passage 50 to the low pressure oil passage 48, and the second check valve 54 allows the oil to flow only in one direction from the supply oil passage 50 to the high pressure oil passage 47. Allow flow.

As shown in FIGS. 1, 3 and 7,
The double lock 4 is formed by a dividing plane orthogonal to the axis X.
Is divided into two blocks, and these are
Board 4₁~ Fifth block board 4_FiveI will call it. Said
Pump cylinder hole 25, motor cylinder hole 39, first valve
The hole 26 and the second valve hole 40 are provided in the first block plate 4.₁-Fifth
Block board 4_FivePump port 25a
Is the third block board 4 _Three~ Fifth block board 4_FiveOver
The motor port 39a is formed with the first block plate 4₁
~ 3rd block board 4_ThreeFormed. High pressure oil passage 4
7 is the second block board 4_TwoBetween the mating surface of
The low pressure oil passage 48 is connected to the fourth block plate 4._FourAnd output shaft 2
Each is formed between the mating surfaces.

Further, the first block plate 4 ₁ to the fifth block plate 4 a series of positioning holes 55 toward ₅ is formed at least two, while fitting the positioning pin 56 to, the first block plate 4 ₁ to 5 divided surfaces mutually block plate 4 ₅ are brazed. At this time, the positioning pin 56 is also brazed to the inner peripheral surface of the positioning hole 55.

As shown in FIG. 4, it is necessary to caulk both ends 56a of the positioning pin 56 before the brazing to prevent the pin 56 from coming out of the positioning hole 55 as follows. This is convenient for brazing work.

Next, the operation of this embodiment will be described.

If the first swash plate assembly 9 is rotated via the input gear 5a by the power of an engine (not shown) while the motor swash plate 19a is held at a certain inclination angle,
As described above, the cooperation between the pump swash plate 9a and the first valve swash plate 9b and the retainer plate 32 makes it possible to forcibly apply the axial reciprocating motion to the pump plunger 27 and the first distribution valve 28 at each timing. Yes, and their proper reciprocation is guaranteed even at high speeds.

As shown in FIG. 8, while the pump plunger 27 passes through the suction area S expanding the oil chamber in the pump cylinder hole 25, the first distribution valve 28 is connected to the pump port 25a. Is communicated to the low-pressure oil passage 48, so that the hydraulic oil in the low-pressure oil passage 48 is sucked into the oil chamber in the pump cylinder hole 25. Further, while the pump plunger 27 passes through the discharge region D in which the oil chamber in the pump cylinder hole 25 is reduced, the first distribution valve 28 communicates the pump port 25a with the high-pressure oil passage 47. The high-pressure hydraulic oil in the hole 25 is discharged to the high-pressure oil passage 47.

On the other hand, in the hydraulic motor M, as shown in FIG. 9, while the motor plunger 41 is in the expansion region Ex in which the oil chamber in the motor cylinder hole 39 is expanded, the second operation is performed.
The distribution valve 42 connects the motor port 39a to the high-pressure oil passage 47, and the motor plunger 41
While in the contraction region Re in which the oil chamber in 9 is reduced,
Since the second distribution valve 42 connects the motor port 39a to the low-pressure oil passage 48, the high-pressure hydraulic oil discharged from the pump cylinder hole 25 to the high-pressure oil passage 47 as described above is supplied to the motor plunger existing in the expansion region Ex. The motor plunger 41 is supplied to the cylinder plunger 39 to apply a thrust to the motor plunger 41. The motor plunger 41 in the contraction region Re discharges hydraulic oil from the motor cylinder hole 39 to the low-pressure oil passage 48 as the contraction stroke progresses. Motor cylinder hole 39
The motor plunger 41, which has received a thrust by the high-pressure hydraulic oil in the cylinder, presses the motor swash plate 19a to exert a rotational torque on the motor swash plate 19a.
Rotate in the same direction as the input gear 5a, and the rotation torque is transmitted from the output shaft 2 to an external load. Also in this case, the cooperation between the motor swash plate 19a and the second valve swash plate 19b and the retainer plate 45 causes the motor plunger 41 and the second
The reciprocating motion of the distribution valve 42 is performed forcibly and with good timing.

In such a normal operation, if the low-pressure oil passage 48 is depressurized due to the leakage of hydraulic pressure from each part of the cylinder block 4, the first check valve 53 is opened, and the low-pressure oil passage 48 is operated from the supply oil passage 50. Oil is replenished. During engine braking, the high-pressure oil passage 47 has a low pressure and the low-pressure oil passage 48 has a high pressure. Thus, the replenishment of the oil pressure leakage at this time is performed through the second check valve 54.

The hydraulic pump P is provided with a pump swash plate 9a.
The hydraulic motor M is a variable displacement type in which the inclination angle of the motor swash plate 19a is variable, while the hydraulic motor M is a variable displacement type in which the inclination angle of the motor swash plate 19a is variable. By increasing or decreasing the capacity of the input member 5
And the speed ratio between the output shaft 2 and the output shaft 2 can be changed.

In such a continuously variable transmission T, annular high-pressure oil passages 47 and low-pressure oil passages 48 are arranged in the axial direction of the cylinder block 4, and both of the cylinders intersect with the oil passages 47 and 48. A large number of first valve holes 26 and second valve holes 26 provided in the cylinder block 4 so as to extend in parallel with the block axis X.
A large number of the first distribution valve 26 and the second distribution valve 42 are slidably fitted in the valve holes 40, respectively.
The motor cylinder hole, the first valve hole 26, and the second valve hole 40 are all arranged in parallel with the cylinder block axis X, and these are inserted into the cylinder block 4 using a parallel multi-axis tool.
It is possible to process easily and quickly. Moreover,
The first and second valve swash plates 9b and 19b, which operate the first and second distribution valves 26 and 42, respectively, with the relative rotation with respect to the cylinder block 4, are similar to the pump and motor swash plates 9a and 19a. Because it is arranged at both ends of
The number of members arranged on the outer periphery of the cylinder block 4 is reduced, which can greatly contribute to the reduction in the radial size of the continuously variable transmission.

Further, the first block is mounted on the cylinder block 4.
H circle C₁Pump plunger 27 and motor plunge
And the first pitch circle C₁Smaller diameter second pick
H circle C_TwoAbove, each of the plungers 27 and 41 has a smaller diameter.
Since the first and second distribution valves 28 and 42 are arranged, each
In the dead space inside the radial direction of the
Each group of distribution valves 28 and 42 will be arranged.
The first pitch circle C ₁Set to a sufficient size and
Provided to each plunger 17, 41 by the plates 9a, 19a
Even if the reciprocating stroke is sufficiently secured, each distribution valve 28,
Existence of 42 groups increases the diameter of cylinder block 4
Instead of radially compact continuously variable transmission T.
Can be. Further, each distribution valve 28, 42 is provided with each plunger.
Each plunger is formed smaller than 27 and 41
Even inside the 27 and 41 groups, each distribution valve 28 and 42 group can be easily
Can be arranged.

[0043] Moreover, since the alternately arranged pump plungers 27 and motor plungers 41 on the first pitch circle C ₁ same, without increasing the diameter of the cylinder block 4, it is possible to reduce the axial dimension Accordingly, the radially and axially compact continuously variable transmission T can be made compact.

Further, the high-pressure oil passage 47 and the low-pressure oil passage 48
Since they are arranged inside the pump plunger 27 group and the motor plunger 41 group, the high and low pressure oil passages 47 and 48 can be formed as short as possible, thereby reducing the absolute amount of bubbles interposed in the hydraulic oil in these oil passages. Thus, the hydraulic transmission efficiency can be improved.

The first swash plate assembly 9 is provided integrally with a pump swash plate 9a and a first valve swash plate 9b arranged on the same slope, and the second swash plate assembly 19 is provided with the same slope. Since the upper motor swash plate 19a and the second valve swash plate 19b are integrally provided, an increase in the axial dimension of the continuously variable transmission T due to the plurality of swash plates can be suppressed. Moreover, the pump swash plate 9a
And the first swash plate 9b to the first swash plate assembly 9,
The second swash plate assembly 9a and the second valve swash plate 19b can be machined into the second swash plate assembly 19 at a time, and mass productivity is high.

Each of the distribution valves 28 and 42 shuts off each of the ports 25a and 39a from both the low-pressure oil passage 48 and the high-pressure oil passage 47 at the midpoint of the reciprocating stroke. Pump port 25a of hole 25
In the opposite direction of rotation of the cylinder block 4
It is connected to the first valve hole 26 out of phase by 0 °, and the motor port 39a of each motor cylinder hole 39 is connected to the second valve hole 40 out of phase by 90 ° in the anti-rotation direction of the cylinder block 4 with respect to it. Because of the connection, the respective plungers 27 and 41 reach the forward limit or the return limit even with the same inclined arrangement of the pump swash plate 9a and the first valve swash plate 9b and the motor swash plate 19a and the second valve swash plate 19b. When the corresponding port 25a,
39a is shut off from both the low-pressure oil passage 48 and the high-pressure oil passage 47, so that each plunger 27, 4
When 1 subsequently changes the movement to the backward movement or the forward movement, the communication switching of the ports 25a and 39a to the low-pressure oil passage 48 or the high-pressure oil passage 47 can be accurately performed.

In this case, the cylinder block 4 is divided into a large number of block plates 4 ₁ to 4 ₄ , and high pressure oil passages 47, low pressure oil passages 48, pump ports 25
a. Since the motor port 39a is formed, even a block plate having such a complicated oil passage can be easily and precisely manufactured by press or casting, and the mass production effect can be enhanced.

FIG. 10 shows a second embodiment in which the present invention is applied only to a swash plate type hydraulic pump P. The pump case 60 supported by a suitable fixed structure includes a cup-shaped case body 6.
0a and a lid 60b coupled to the open end thereof by bolts 65. An input shaft 61 driven by an engine (not shown) is provided on an end wall of the case body 60a with a pair of angular contact bearings 62, The suction pipe 63 and the discharge pipe 64 are attached to the lid body 60b. The suction pipe 63 is connected to an oil reservoir or a low-pressure oil passage (not shown), and the discharge pipe 64 is connected to a hydraulic device (not shown) serving as a load.

In the pump case 60, the swash plate holder 8 is fixed to the input shaft 61 by bolts 66, and the swash plate assembly 9 is rotatable around the swash plate assembly 9 via the ball bearing 10 and the angular contact bearing 11. It is supported by The swash plate assembly 9 integrally includes a pump swash plate 9a and a valve swash plate 9b similarly to the first swash plate assembly 9 of the previous embodiment. Also, the cylinder block 4 is provided on the lid 60b.
Are fixed by bolts 67 so as to be coaxial with the input shaft 60.

Similarly to the layout of the hydraulic pump P of the previous embodiment, the cylinder block 4 is connected to an odd number and a large number (five in the illustrated example) of pump cylinder holes 25 and valve holes 26, and each of the pump cylinder holes 25. A pump port 25a and an annular low-pressure oil passage 48 are formed, and a pump plunger 27 and a distribution valve 28 are fitted in the pump cylinder hole 25 and the valve hole 26, respectively. The annular high-pressure oil passage 47 is formed between the joining surfaces of the cylinder block 4 and the lid 60b. The low-pressure oil passage 48 communicates with the suction pipe 63, and the high-pressure oil passage 47 communicates with the discharge pipe 64.

The pump plunger 27 and the distribution valve 28
The spherical end portions 29a and 30a are held in engagement with the spherical concave portions 29b and 30b of the pump swash plate 9a and the valve swash plate 9b by the retainer plate 32 having the same structure as that of the previous embodiment.

[0052] Cylinder block 4 in this case is divided axially into four block plates 4 ₁ to 4 _2. Pump Although the pump cylinder hole 25 to the first to third block plates 4 ₁ to 4 ₃ from the left side in the figure is formed, the first block plate 4 ₁ which has become thicker than the others, are formed thereto The cylinder hole 25 is finished with high precision so as to slidably support the pump plunger 27, but the pump cylinder hole 25 of the _second and third block plates 4 ₂ and 4 ₃
It is slightly larger and rougher than that of ₁ . Also the second
Low pressure oil passage 48 to the block plates 4 _2, the third block plate 4 ₃
Pump ports 25a are formed respectively. Fourth block plate 4 ₄ They become larger in diameter than the others, its outer peripheral portion is fixed to the cover 60b with bolts 67. By doing so, it is possible to first to fourth block plates 4 ₁ to 4 ₄ thinning, it is possible to perform press working with a mass production. The first to fourth block plates 4 ₁ to 4 ₄ are being positioned mutually brazing similarly to the foregoing embodiment.

The other configuration is the same as that of the hydraulic pump P of the previous embodiment.
In the figure, portions corresponding to those of the hydraulic pump P of the previous embodiment are denoted by the same reference numerals, and description thereof is omitted.

The present invention is not limited to the above embodiments, and various design changes can be made without departing from the gist of the present invention.

[0055]

As described above, according to the first feature of the present invention, a large number of cylinder holes arranged annularly in parallel to the cylinder block axis and parallel to the axis on a pitch circle surrounding the cylinder block, and a plurality of cylinder holes individually connected to these cylinder holes. A plurality of plungers slidably fitted in the many cylinder holes of the cylinder block, and the plungers are engaged with tips of the plungers projecting toward one end of the cylinder block, and are rotated relative to the cylinder block. A plunger swash plate, a low-pressure oil passage, and a high-pressure oil passage, which are arranged to reciprocate these plungers, and are arranged in a cylinder block in a circular arrangement parallel to the axis on a pitch circle surrounding the axis, and provided on a cylinder block. A large number of spool-type distribution valves for reciprocating in the direction to alternately switch the port of each cylinder hole to a low-pressure oil passage and a high-pressure oil passage, and a series of these distribution valves. In a swash plate type hydraulic device, which comprises a valve swash plate that engages with a tip protruding toward one end side of a dub lock and reciprocates these distribution valves with relative rotation with a cylinder block, each distribution valve has a smaller diameter than each plunger. Since the second pitch circle was formed with a smaller diameter than the first pitch circle, the first pitch circle was set to a sufficient size, and a sufficient reciprocating stroke given to the plunger by the plunger swash plate was ensured. In addition, the existence of the distribution valve group does not increase the diameter of the cylinder block, and the hydraulic device can be made compact in the radial direction. Further, since the distribution valve is formed smaller in diameter than the plunger, the distribution valve group can be easily arranged even inside the plunger group. According to the second feature of the present invention, the valve swash plate is disposed on the same slope as the plunger swash plate and is formed integrally with the plunger swash plate. And the swash plate of the plunger and the valve swash plate can be easily integrated.

According to a third feature of the present invention, the port of each cylinder hole is controlled to be switched by the distribution valve at a position where the phase is shifted by 90 ° in the circumferential direction of the cylinder block with respect to the cylinder hole. With such a configuration, the operation of the distribution valve can be accurately and accurately controlled in accordance with the reciprocating position of the plunger even with the same-directional inclination arrangement of the plunger swash plate and the valve swash plate.

[Brief description of the drawings]

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

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a sectional view showing a partially modified example of FIG. 3;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 1;

FIG. 6 is a sectional view taken along line 6-6 of FIG. 1;

FIG. 7 is an exploded perspective view of a cylinder block.

FIG. 8 is an operation timing chart of a pump plunger and a first distribution valve.

FIG. 9 is an operation timing chart of a motor plunger and a second distribution valve.

FIG. 10 is a vertical sectional side view of a hydraulic pump according to a second embodiment of the present invention.

[Explanation of symbols]

C ₁ · · · · first pitch circle C ₂ · · · · second pitch circle P · · · · · hydraulic device (hydraulic pump) M · · · · · hydraulic device (hydraulic motor) X · · · · · Cylinder block axis line 4 ... Cylinder block 9a ... Plunger swash plate (pump swash plate) 9b ... Valve swash plate (first valve swash plate) 19a ... Plunger swash plate (motor swash plate) 19b: valve swash plate (second valve swash plate) 25: cylinder hole (pump cylinder hole) 25a: port (pump port) 27: plunger (pump plunger) 28: · Distribution valve (first distribution valve) 39 ··· Cylinder hole (motor cylinder hole) 41 ··· Plunger (motor plunger) 42 ··· Distribution valve (second distribution valve) 47 ··· High pressure Oil passage 48 ・ ・ ・ ・ Low pressure oil passage

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Masako Takahashi 1-4-1, Chuo, Wako-shi, Saitama Pref.

Claims (3)

[Claims] 1. A first frame surrounding a cylinder block axis (X).
A large number of cylinder holes (25, 39) annularly arranged in parallel with the axis (X) on the pitch circle (C ₁ ), and a large number of ports (25) individually connected to these cylinder holes (25, 39).
a, 39a), a large number of plungers (27, 41) slidably fitted in the large number of cylinder holes (4), and these plungers (27, 41).
41), the plunger swash plate disposed to engage with the tip protruding toward one end of the cylinder block (4) to reciprocate the plungers (27, 41) by relative rotation with the cylinder block (4). (9a, 19a), a low pressure oil passage (47) and a high pressure oil passage (48), and the axis (X).
Are provided in the cylinder block (4) in an annular arrangement parallel to the axis (X) on a second pitch circle (C ₂ ) surrounding the cylinder, and reciprocate in the axial direction to relocate the ports of the cylinder holes (25, 39). (25a, 39a) a number of spool-type distribution valves (28, 42) for alternately switching the communication between the low-pressure oil path (47) and the high-pressure oil path (48), and these distribution valves (28, 42)
And a valve swash plate (9b, 9b) which engages with the tip protruding toward one end of the cylinder block (4) to reciprocate these distribution valves (28, 42) with relative rotation with the cylinder block (4).
19b), each distributing valve (28, 42) is connected to each plunger (27, 41).
A swash plate type hydraulic device having a smaller diameter and a second pitch circle (C ₂ ) set smaller in diameter than the first pitch circle (C ₁ ). 2. A swash plate (9a, 19b) according to claim 1, wherein the valve swash plate (9b, 19b) is connected to the plunger swash plate (9a, 19b).
a) and placed on the same slope as the plunger swash plate (9).
a, 19a), formed integrally with the swash plate type hydraulic device. 3. The port (25a, 39) of each cylinder hole (25, 39) according to claim 2.
a) is formed such that switching is controlled by the distribution valve (28, 42) at a position where the phase is shifted by 90 ° in the circumferential direction of the cylinder block (4) with respect to the cylinder hole (25, 39). A swash plate type hydraulic device characterized by the above-mentioned.