JPH0424585B2 - - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention (1) Industrial Field of Application The present invention relates to a hydraulic oil distribution device for a swash plate type hydraulic device used as a swash plate type hydraulic pump or a hydraulic motor;
Specifically, it has a large number of cylinder holes in an annular arrangement,
With the relative rotation of the cylinder block in which the plunger group is slid into these cylinder holes and the plunger swash plate that engages with the protruding end of the plunger group, each cylinder hole and the high-pressure oil chamber and low-pressure oil chamber formed in the cylinder block This invention relates to an improvement in a hydraulic oil distribution device that controls the exchange of hydraulic oil between.

(2) Prior Art In this hydraulic oil distribution device for a swash plate type hydraulic system, a high pressure oil chamber and a low pressure oil chamber are formed in the cylinder block and are concentric with each other surrounding the axis of the cylinder block. A large number of distribution valves are arranged in a radial manner to alternately move each cylinder hole to communicate with the high-pressure oil chamber and the low-pressure oil chamber by reciprocating between positions. In order to provide reciprocating motion to the distribution valve group, an eccentric ring circumscribing the distribution valve group is arranged eccentrically with respect to the center of rotation of the cylinder block.

(3) Problems to be solved by the invention In the swash plate type hydraulic system, since the annularly arranged plunger group is arranged parallel to the axis of the cylinder block, the axial dimension is larger than the outer diameter dimension of the cylinder block. It tends to get bigger. If a conventional hydraulic oil distribution device is adopted for such a hydraulic system, the distribution valve group must be disposed at one end of the plunger group, which further increases the axial dimension of the cylinder block and reduces the overall size of the hydraulic system. This poses a problem of making compactization difficult.

The present invention has been made in view of the above circumstances, and enables the installation of a distribution valve without increasing the axial dimension of the cylinder block, thereby contributing to the compactness of the hydraulic system. The purpose is to provide an oil distribution device.

B. Structure of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a structure in which a high pressure oil chamber and a low pressure oil chamber are arranged so as to surround the axis of the cylinder block and to be aligned in the axial direction. A plunger group includes a number of distribution valves formed in an annular shape and reciprocating between positions on one side and the other side in the axial direction of the cylinder block to alternately communicate each cylinder hole with a high-pressure oil chamber and a low-pressure oil chamber. The valve swash plate connected to the end of the distribution valve group is tilted with respect to the axis of the cylinder block so as to provide reciprocating motion to each distribution valve as the cylinder block and plunger swash plate rotate relative to each other. It is characterized by being supported by a support system of the plunger swash plate.

This hydraulic fluid distribution device can be adopted for both hydraulic pumps and hydraulic motors.

(2) Operation When the cylinder block and plunger swash plate rotate relative to each other, each distribution valve is reciprocated in the axial direction of the cylinder block by the valve swash plate, and the corresponding cylinder hole is connected to the high pressure oil chamber and the low pressure oil chamber. alternately communicate with each other to exchange hydraulic oil.

Since the distribution valve group is installed in an annular configuration concentric with the plunger group, its installation does not require an increase in the axial dimension of the cylinder block.

Moreover, since the valve swash plate can be installed using the space around the plunger swash plate, the axial dimension of the hydraulic system is not increased thereby.

(3) Embodiment An embodiment of the present invention will be described below with reference to the drawings. First, in FIG. 1, U is a power unit for an automobile, which includes an engine E, a hydrostatic continuously variable transmission T equipped with the hydraulic oil distribution device of the present invention, and a differential gear.
It is constructed by housing and supporting Df in a casing C that serves as a stationary machine frame.

The crankshaft 1 of the engine E and the input shaft 2 of the continuously variable transmission T disposed on the right end side thereof are disposed coaxially and connected via a torque damper Td. Further, the output gear 3 of the continuously variable transmission T is arranged as close as possible to the engine E, and the differential gear Df
The ring gear 4 meshes with the ring gear 4. The left and right output shafts 5, 5' of the differential gear Df are the crankshaft 1 and input shaft 2.
The vehicle is arranged parallel to the vehicle, and is designed to drive left and right axles (not shown).

The right end of the input shaft 2 protrudes outside the casing C, and is equipped with a pulley 6 for driving auxiliary equipment such as a power steering hydraulic pump and an air conditioning compressor.
is fixed to its protruding end.

In FIGS. 2 and 3, the continuously variable transmission T
consists of a variable displacement swash plate type hydraulic pump P and a constant displacement type swash plate type oil motor M, and in this embodiment, the present invention is applied to the hydraulic oil distribution device for the hydraulic motor M.

The hydraulic pump P has a cylindrical cylinder block 7.
A large number and an odd number of cylinder holes 8, 8 in an annular arrangement are provided surrounding the center of rotation and with the right end open.
..., a large number of pump plungers 9, 9... that are slidably fitted into these cylinder holes 8, 8, respectively, a pump swash plate 10 that abuts the outer ends, ie, right ends, of these pump plungers 9, 9..., and this pump swash plate. A trunnion shaft 12 having a semicircular cross-section and supporting the back surface of the trunnion shaft 10 via a thrust roller bearing 11 on a flat surface.
and a swash plate anchor 13 that rotatably supports the cylindrical surface of the trunnion shaft 12.

The swash plate anchor 13 has bolts 15 attached to the casing C.
It is fixed in place.

The axis O ₁ of the trunnion shaft 12 is bored in the swash plate anchor 23 in order to allow the rotation of the trunnion shaft 12 by a predetermined angle while preventing its axial movement.
The bolt 23 is passed through the circular arc-shaped long hole 22 centered at
is fixed to one end surface of the trunnion shaft 12 (the third
(see Figure and Figure 11).

The pump swash plate 10 is tilted by rotation of the trunnion shaft 12 between an upright position perpendicular to the axis of the cylinder block 7 and two maximum tilt positions tilted at a certain angle on both the left and right sides thereof. The inclined state allows the pump plungers 9, 9, . . . to reciprocate as the cylinder block 7 rotates, thereby repeating the suction and discharge strokes.

On the other hand, the hydraulic motor M has the cylinder holes 8, 8
...Cylinder holes 18, 18, which have the same number as the cylinder holes 8, 8..., are arranged on a pitch circle that is concentric with the pitch circle of the group and has a slightly larger diameter, and are provided in the cylinder block 7 with the left end open. , motor plungers 19 , 19 , . The motor swash plate holder 27 is supported via a thrust roller bearing 26, and the output gear 3 is integrally formed on the outer periphery of the motor swash plate holder 27.

In the above, the inner cylinder holes 8, 8... groups and the outer cylinder holes 18, 18... groups are shifted in position from each other by one-half pitch of each cylinder hole in the circumferential direction of the cylinder block 7, and The inscribed circles of the cylinder holes 18, 18... group are arranged so as to pass through the inner cylinder holes 8, 8... group.

The motor swash plate 20 also has a motor swash plate holder 27.
Therefore, the motor swash plate holder 27 is held in a state inclined at a certain angle with respect to the axis of the cylinder block 7 with the virtual trunnion axis O ₂ orthogonal to the axis of the cylinder block 7 as the center, and the relative rotation between the cylinder block 7 and the motor swash plate holder 27 is prevented. Sometimes motor plunger 1
9, 19... can be reciprocated to repeat the expansion and contraction steps.

The input shaft 2 passing through the center of the cylinder block 7 is connected to the cylinder block 7 via a spline 32. The right end of this input shaft 2 is a pump swash plate 10,
The first shaft extends through the trunnion shaft 12 and the swash plate anchor 13 and is locked to the right end thereof.
A thrust roller bearing 37 is interposed between the thrust support plate 35 and the swash plate anchor 13. The right end of the input shaft 2 is rotatably supported by the swash plate anchor 13 via a needle bearing 38 and by the casing C via a bush 39.

Note that the first thrust support plate 35 is coupled to the input shaft 2 via a key 43.

Further, the left end of the input shaft 2 extends to pass through the motor swash plate 20 and the motor swash plate holder 27, and the second thrust support plate 36 and the motor swash plate holder 27 are connected to the second thrust support plate 36, which is locked to the outer periphery of this left end. A thrust roller bearing 40 is interposed between them, and a needle bearing 41 is interposed between the motor swash plate holder 27 and the input shaft 2. The left end of the input shaft 2 is rotatably supported by the casing C together with the second thrust support plate 36 via a roller bearing 42.

In order to rotate each swash plate 10, 20 synchronously with the cylinder block 7, each swash plate 10, 20 has a
Spherical ends 9a, 1 of corresponding plungers 9, 10
Spherical recesses 10a and 20a are respectively formed to engage the cylindrical portions 9a.

A hydraulic closed circuit is formed between the hydraulic pump P and the hydraulic motor M as follows.

The cylinder block 7 has an annular inner oil chamber 45 on its inner periphery, and first, second, and third outer oil chambers 46, 47, and 48, which are also annular and arranged in sequence from the right side in the axial direction, on the outer periphery. The inner oil chamber 45 and the third outer oil chamber 58 are communicated with each other via a plurality of radially extending oil passages 49 (see FIG. 8).

The cylinder block 7 also includes a hydraulic pump P.
The first valve holes 51, 51 have the same number as the cylinder holes 8, 8, and extend radially adjacent to their dead end portions.
... (see Fig. 4), and second valve holes 52, 52..., which are the same in number as the cylinder holes 18, 18... of the hydraulic motor M, and which extend in the axial direction adjacent to the outside in the radial direction. .

The first valve holes 51, 51... reach the inner oil chamber 45 from the outer peripheral surface of the cylinder block 7, and each valve hole 5
1, there is a pump port a (see Fig. 3) that passes through the dead end of the adjacent cylinder hole 8.
Then, an oil passage 53 located radially outward of the pump port a and communicating with the first outer oil chamber 56 (see FIGS. 3 and 6) opens.

Spool-type first distribution valves 55, 55... are respectively slid into these first valve holes 51, 51..., and an eccentric ring 57 surrounding them is mounted on a ball bearing at the outer end of these first distribution valves 55, 55... 58. to force their engagement,
The outer ends of the first distribution valves 55, 55... each have an eccentric ring 5.
7 and a concentric force ring 59.

As shown in FIGS. 2, 4, and 4A, the eccentric wheel 57 is connected to the swash plate anchor 13 via a pivot 60 parallel to the input shaft 2 between two positions, a hydraulic operation position n and a lock-up position l. are connected so that they can swing. The eccentric wheel 57 is moved approximately along the trunnion axis O 1 with the center of the input shaft 2 as a reference by a control device (not shown) that engages with a protrusion 57 a protruding from the outer peripheral surface of the eccentric wheel 57 on the opposite side to the pivot shaft ₆₀ . The eccentricity is controlled to be ε at the hydraulic operating position n and zero at the lock-up position l (that is, the eccentric wheel 57 is concentric with the input shaft 2).

When the eccentric wheel 57 occupies the hydraulic operating position n (see FIG. 4), when the cylinder block 7 rotates, each first distribution valve 55 is caused by the eccentric wheel 57 to have an eccentric amount in the first valve hole 51. The cylinder block 7 is reciprocated between the inner and outer positions in the radial direction with a stroke of twice the distance ε, and thereby the hydraulic pump P has a discharge area D and a suction area S.
is given.

That is, in the discharge region D, as the cylinder block 7 rotates, the first distribution valve 55 moves in the inner position side, and the corresponding pump port a is connected to the first outer oil chamber 4.
6 and the inner oil chamber 4.
5 and pump plunger 9 during the discharge stroke.
As a result, hydraulic oil is discharged from the cylinder hole 8 to the first outer oil chamber 46 via the oil passage 53. In the suction region S, the first distribution valve 55 moves to the outer position side, communicates the corresponding pump port a with the inner oil chamber 45, and disconnects the oil passage 53 from the pump plunger 9 during the suction stroke. As a result, hydraulic oil is sucked into the cylinder hole 8 from the inner oil chamber 45.

Between the above-mentioned regions D and S, a switching neutral region is provided in which the first distribution valve 55 disconnects the pump port a from either the inner oil chamber 45 or the oil passage 53.

Moreover, when the eccentric wheel 57 occupies the lock-up position l (see FIG. 4A), all the first distribution valves 55 are closed to the eccentric wheel 5, despite the rotation of the cylinder block 7.
7, the switch is held in the neutral state and all pump ports a are closed.

Again in FIGS. 2 and 3, the second valve holes 52, 52... are connected to the first, second and third outer oil chambers 4.
6, 47, and 48, and penetrates through the cylinder block 7, and each valve hole 52 has a motor connected to the adjacent cylinder hole 18 at an intermediate portion between the first and third outer oil chambers 46, 48. Port b (see FIGS. 2 and 7) opens.

Spool-type second distribution valves 56, 56... are slid into the second valve holes 52, 52..., respectively. These second distribution valves 56, 56, . will be combined.

The valve swash plate 62 rotates the cylinder block 7 around a second imaginary trunnion axis O ₃ which is set with a phase shift of 90° around the axis of the cylinder block 7 with respect to the imaginary trunnion axis O ₂ of the motor swash plate 20 . cylinder block 7 and motor swash plate holder 27.
During relative rotation with the second distribution valve 56, the second distribution valves 56, 56, . . . are reciprocated in the axial direction with a predetermined stroke. The expansion area Ex and contraction area of the hydraulic motor M are determined by the positions of these second distribution valves 56, 56...
Sh can be determined.

That is, as shown in FIG. 5, in the expansion region Ex,
When the second distribution valve 56 is at or near the left movement limit, the corresponding motor boat b is communicated with the first outer oil chamber 46 and disconnected from the second outer oil chamber 47, and the expansion is caused from the first outer oil chamber 46. High-pressure hydraulic oil is supplied to the cylinder hole 18 of the motor plunger 19 during stroke. In the contraction region Sh, the second distribution valve 5
6 is at or near the right movement limit, the corresponding motor boat b is communicated with the second outer oil chamber 47 and disconnected from the first outer oil chamber 46, and the cylinder hole 18 is opened by the motor plunger 19 during the contraction stroke.
Hydraulic oil is discharged from the second outer oil chamber 47 to the low-pressure second outer oil chamber 47 side.

Each second distribution valve 56 has a second
and without interfering with communication between the third outer oil chambers 47 and 48,
Therefore, the oil discharged to the second outer oil chamber 47 side flows back to the inner oil chamber 45 via the third outer oil chamber 48 and the oil passage 49.

In the above configuration, with the pump swash plate 10 held at a certain inclination angle and the eccentric wheel 57 held at the hydraulic operating position n, the cylinder block 7 is rotated by the power of the engine E via the input shaft 2. First, in the hydraulic pump P, the pump plunger 9 that performs the discharge operation pumps hydraulic oil from the cylinder hole 8 to the first outer oil chamber 46 as described above while passing through the discharge area D, and also performs the suction operation. The pump plunger 9 sucks hydraulic oil from the inner oil chamber 45 into the cylinder hole 8 while passing through the suction region S.

The high pressure hydraulic oil sent to the first outer oil chamber 46 is
While being supplied to the cylinder hole 18 of the motor plunger 19 located in the expansion region Ex of the hydraulic motor M,
Hydraulic oil is discharged from the cylinder hole 18 of the motor plunger 19 in the contraction region Sh to the inner oil chamber 45 as described above.

The output gear 3 is driven by the sum of the rotational torque that the cylinder block 7 applies to the motor swash plate 20 via the motor plungers 19, 19, . The rotational torque is transmitted to the differential gear Df.

Here, n _P ... Number of pump plungers 9 n _M ... Number of motor plungers 19 d _P ... Diameter of pump plungers 9 d _M ... Diameter of motor plungers 19 D _P ... Pitch circle diameter of pump plunger 9 groups D _M ... Motor Pitch circle diameter of the plunger 19 group O _P ...Inclination angle of the pump swash plate 10 with respect to the vertical plane O _M ... Inclination angle of the motor swash plate 20 with respect to the vertical plane S _P ... Stroke of the pump plunger 9 S _M ... Stroke of the motor plunger 19 Ni If the rotational speed of the input shaft 2 is the rotational speed of the output cylinder shaft 25, then the gear ratio π can be determined by the following equation.

π＝Ni／No＝1/1−n _P・d _P ²・S _P ／n _M・d _M ²・S _M ＝1/1−n _P・d _P ² .D _P・tanθ _P ／n _M・d _M ²・D _M・tan
θ _M Therefore, when the motor swash plate 20 is fixed at a constant inclination angle θ _M as in the illustrated example, if the inclination angle θ _P of the pump swash plate 10 is set to θ _P =0, π≒
1, that is, Ni≈No, and a direct connection state is obtained.

If θ _P <, then π>1, that is, Ni<No,
An accelerated state is obtained.

If 0<tanθ _P <n _M・d _M ²・D _M /n _P・d _P ²・D _P・tanθ _M , then Ni>No>0 and a deceleration state is obtained.

If tanθ _P =n _M ·d _M ² ·D _M /n _P ·d _P ² ·D _P ·tanθ _M , No=0 regardless of the Ni content, and a neutral state can be obtained.

If tanθ _P >n _M・d _M ²・D _M /n _P・d _P ²・D _P・tanθ _M , No<0 and a reversed state can be obtained.

The above is illustrated in FIG. 12. By the way, even in the case of direct connection, between the plungers 9, 19 and the cylinder holes 8, 18, the distribution valve 55,
56 and the valve holes 51 and 52, transmission efficiency is inevitably reduced due to unavoidable oil leakage from sliding parts exposed to high oil pressure, and moreover, No=Ni is used frequently while driving a car. Therefore, in such a state, if the eccentric wheel 57 is controlled to the lock-up position l, all the pump ports a, a,... are closed by all the first distribution valves 55, 55, etc., as described above, and thereby the hydraulic pump Since the oil passage between P and the hydraulic motor M is blocked, the number of sliding parts exposed to high oil pressure is greatly reduced, and a decrease in transmission efficiency due to oil leakage can be suppressed.

During operation of the hydraulic pump P and the hydraulic motor M, the pump swash plate 10 is connected to the pump plungers 9, 9, . . .
Further, the motor swash plate 20 is connected to the motor plunger 19,1.
9... Each group receives a thrust load in the opposite direction, but the thrust load that the pump swash plate 10 receives is due to the thrust roller bearing 11 and the trunnion shaft 1.
2. The thrust load transmitted to the input shaft 2 via the swash plate anchor 13, the thrust roller bearing 37, and the first thrust support plate 35, and also received by the motor swash plate 20, is transferred to the thrust roller bearing 26, the motor swash plate holder 27, and the thrust roller bearing 4
It is also transmitted to the input shaft 2 via the 0 and second thrust support plates 36. Therefore, the above-mentioned thrust load only causes tensile stress on the input shaft 2, and does not act on the casing C supporting the shaft 2 at all.

By the way, the pump plungers 9, 9... groups and the motor plungers 19, 19... groups are shifted in position from each other in the circumferential direction of the cylinder block 7, and the inscribed circle of the motor plungers 19, 19... groups is the same as that of the pump plungers 9, 9. ...Since they are arranged so as to pass through the group, the pump plungers 9, 9 can be arranged while ensuring sufficient wall thickness between the adjacent cylinder holes 8, 18.
... group and the motor plunger groups 19, 19... can be arranged close to each other, and as a result, by only slightly increasing the diameter of the cylinder block 7, its axial dimension can be significantly reduced.

This is extremely effective in making the power unit U more compact, especially in the case of a power unit U in which the engine E and the transmission T are arranged in the axial direction.

Further, the second distribution valves 56, 5 reciprocate in the axial direction.
6..., the cylinder block 7 is made slightly larger in diameter, making it possible to install the second distribution valves 56, 56..., thereby making it possible to further reduce the axial dimension of the cylinder block 7. Moreover,
Valve swash plate 62 that drives the second distribution valves 56, 56...
Since the valve swash plate 62 is arranged so as to surround the motor swash plate 20, the axial dimension of the transmission T is not increased by the valve swash plate 62.

2 and 6, the cylinder block 7 further includes one or more third valve holes 65 extending between and parallel to the second valve holes 52, 52...
(Three in the illustrated example) are provided. This valve hole 65
extends across the first and second outer oil chambers 46, 47, and has an inner end closed and an outer end open at the right end surface of the cylinder block 7. This valve hole 65
A spool-type clutch valve 66 is slidably connected to the spool-type clutch valve 66.

The clutch valve 65 has an annular groove 67 on the outer periphery of the valve head protruding from the right end surface of the cylinder block 7, and an inner actuator that is slidably fitted on the outer periphery of the cylinder block 7 is provided in the annular groove 67. An inwardly bent claw 68a of the ring 68 is engaged. An outer operating ring 69 surrounding the inner operating ring 68 is connected via a release bearing 70, and a pinion 72 is engaged with a rack 71 that projects from one end of the outer operating ring 69 and extends in the axial direction. be done.
The pinion 72 is rotatably supported by the swash plate anchor 13, and a clutch lever 73 is fixed to one end of the pinion 72.

If the pinion 72 is rotated by the clutch lever 73 and the outer operating ring 69 is moved left and right, the clutch valve 6 is moved through the release bearing 70 and the inner operating ring 68 even while the cylinder block 7 is rotating.
6 is the left clutch position (solid line position in Figure 2)
and the right clutch-off position (the position indicated by the chain line in FIG. 2). Thus, the clutch valve 66 has the first and second valves in its clutch position.
The outer oil chambers 46, 47 are shut off, and in the clutch off position, the two oil chambers 46, 47 are communicated with each other. The high-pressure hydraulic oil supplied to the first outer oil chamber 46 through the flow immediately flows out to the low-pressure second outer oil chamber 47, and the hydraulic pump P becomes short-circuited. A clutch-off state is obtained in which hydraulic power transmission is cut off.

As shown in FIG. 9, in the clutch valve 66, one or more notches 74 are formed in the edge portion of the land portion 66a, which controls opening and closing between the two oil chambers 46 and 47, located between the two oil chambers 46 and 47. provided. This notch 74 can finely control communication between the oil chambers 46 and 47 when switching the clutch valve 66 from the clutch-off position to the clutch-on position.
As a result, a half-clutched state can be precisely obtained.

Referring again to FIGS. 1 and 2, a main oil passage 75 is bored in the center of the input shaft 2 and has a dead end at the back. The open end of this main oil passage 75 is connected to the supply pump 7
6, the replenishment pump 76 communicates with the oil reservoir 77 at the bottom of the casing C through the first thrust support plate 3.
It is driven by a drive gear 78 carved on the outer periphery of 5. Therefore, while the input shaft 2 is rotating, the oil sump 7 is always
7 is fed to the main oil passage 75 by a replenishment pump 76.

The main oil passage 75 communicates with the inner oil chamber 45 via a radial first supply hole 79 bored in the input shaft 2 . The first step is to prevent oil from flowing back in the direction of
A check valve 81 is provided. This first check valve 81
is biased in the valve closing direction by a leaf spring 83 surrounding the input shaft 2.

The main oil passage 75 also communicates with the first outer oil chamber 46 via a second supply hole 80 that is bored in the input shaft 2 and the cylinder block 7 and extends in the radial direction as a whole, and is connected to the second supply hole 80. is the first outer oil chamber 46
A second check valve 82 is interposed to prevent oil from flowing backward in the direction from the main oil passage 75 to the main oil passage 75.
is urged in the valve closing direction by the valve spring 84.

Therefore, during normal output operation in which the hydraulic motor M is hydraulically driven from the hydraulic pump P, the main oil passage 75
from the low pressure inner oil chamber 4 through the first supply oil passage 79.
5, and during engine braking when the hydraulic pump P is hydraulically driven from the hydraulic motor M, the main oil passage 75 passes through the second supply oil passage 80,
Hydraulic oil is supplied to the first outer oil chamber 46 whose pressure has changed to low pressure, and the amount of hydraulic oil leaked from the hydraulic closed circuit can be compensated for.

3 and 10, a speed change control device 85 for controlling the angle of the pump swash plate 10 is connected to the trunnion shaft 12. As shown in FIGS. This speed change control device 85 includes a sector gear 88 fixed to the other end of the trunnion shaft 12 by a bolt 86 and a pair of knock pins 87, 87, a worm gear 89 meshing with the sector gear 88, and a drive shaft 90 connected to the worm gear 89. The worm gear 89 is rotatably supported by a gear box 93 fixed to the casing C with bolts 92 via bearings 94 and 95. In addition, the electric motor 91
The stator of is fixed in place in the casing C.

When the electric motor 91 is rotated in the forward or reverse direction, the rotation is reduced and transmitted from the worm gear 89 to the sector gear 88, and further transmitted to the trunnion shaft 12, which rotates the rotation in the upright direction of the pump swash plate 10 or It can be rotated in the tilting direction.

Also, the electric motor 91 is stopped and the pump swash plate 1
0 is held at an arbitrary angle, the pump swash plate 10 receives a moment in the upright or tilting direction from the motor plungers 19, 19..., and even if that moment is transmitted to the sector gear 88 via the trunnion shaft 12, the sector gear 88 Since it is not possible to drive the worm gear 89 from the
is in a locked state and does not allow rotation of the trunnion shaft 12, thus ensuring that the pump swash plate 10 is held in its current position.

In the embodiments described above, the hydraulic motor corresponds to the hydraulic system of the present invention, and therefore the motor swash plate corresponds to the plunger swash plate. Further, the first outer oil chamber 45 corresponds to the high pressure oil chamber of the present invention, and the second outer oil chamber 46 corresponds to the low pressure oil chamber.

In addition, the transmission T is reversed to the input and output sides,
The hydraulic pump P is used as a hydraulic motor, and the hydraulic motor M
can also be used as a hydraulic pump.

C. Effects of the Invention As described above, according to the present invention, the high pressure oil chamber and the low pressure oil chamber are formed in an annular shape surrounding the axis of the cylinder block and aligned in the axial direction. A large number of distribution valves that reciprocate between the side position and the other side position to alternately communicate each cylinder hole with the high pressure oil chamber and the low pressure oil chamber are arranged in a ring shape concentric with the plunger group, and the cylinder block and plunger tilt The valve swash plate connected to the end of the distribution valve group is tilted with respect to the axis of the cylinder block and supported on the support system of the plunger swash plate in order to give reciprocating motion to each distribution valve as the plates rotate relative to each other. The distribution valve group can be installed without increasing the axial dimension of the block, and the installation of the valve swash plate does not require any particular increase in the axial dimension of the hydraulic system. Compactness can be achieved.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, and FIG. 1 is a vertical cross-sectional rear view of the main parts of an automobile power unit equipped with a hydrostatic continuously variable transmission to which the present invention is applied, and FIG. 2 is a diagram showing the above-mentioned transmission. 3 is a sectional view taken along the - line in FIG. 2, FIG. 4 is a sectional view taken along the - line in FIG.
Figure 6 is a - line cross section rotation diagram of Figure 3.
A line sectional view, FIG. 7 is a - line sectional view of FIG. 2,
Figure 8 is a - line sectional view of Figure 2, Figure 9 is a cross-sectional view of Figure 2.
Figure 10 is an enlarged view of the surrounding area of the clutch valve (shown in a half-clutch state), Figure 10 is a sectional view taken along the - line in Figure 3, Figure 11 is a view taken in the direction of the XI arrow in Figure 3, and Figure 12 is an oblique view of the pump. FIG. 3 is a diagram showing the relationship between the inclination angle of the plate and the motor swash plate and the speed ratio. P...Hydraulic pump as hydraulic device, 7...Cylinder block, 18...Cylinder hole, 19...Plunger, 20...Motor swash plate as plunger swash plate,
46...First outer oil chamber as a high pressure oil chamber, 47...Second outer oil chamber as a low pressure oil chamber, 56...Distribution valve, 6
2...Valve swash plate.

Claims (1)

[Claims] 1. With the relative rotation of the cylinder block which has a large number of cylinder holes arranged in an annular arrangement and in which the plunger group is slidably connected, and the plunger swash plate that engages with the protruding end of the plunger group, each cylinder hole and the cylinder This is a hydraulic oil distribution device for a swash plate type hydraulic system that controls the delivery and reception of hydraulic oil between a high pressure oil chamber and a low pressure oil chamber formed in a cylinder block. The cylinder hole is formed in an annular shape so as to surround the cylinder block and line up in the axial direction, and reciprocates between the positions on one side and the other side in the axial direction to alternately communicate each cylinder hole with the high-pressure oil chamber and the low-pressure oil chamber. A large number of distribution valves are arranged in an annular shape concentric with the plunger group, and the valve swash plate is connected to the end of the distribution valve group to give reciprocating motion to each distribution valve as the cylinder block and the plunger swash plate rotate relative to each other. A hydraulic oil distribution device for a swash plate type hydraulic system, in which a plunger is tilted with respect to the axis of a cylinder block and supported on a support system of a plunger swash plate.