JPH0745870B2 - Swash plate type hydraulic system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Object of the Invention (1) Field of Industrial Application The present invention relates to a swash plate type applied to a hydraulic pump or a hydraulic motor, that is, arranged in a ring parallel to and surrounding a rotation axis. A cylinder having a large number of cylinder holes formed therein; a plurality of plungers having a spherical end portion that is slidably fitted into the cylinder hole and protrudes from one end surface of the cylinder; A swash plate holder that is movably disposed; and a swash plate that is rotatably supported by the swash plate holder and that abuts on the spherical end of each plunger. The invention relates to a swash plate type hydraulic pump for generating a swash plate or a swash plate type hydraulic motor for relatively rotating a cylinder and a swash plate by hydraulically reciprocating a plunger. .

(2) Conventional Technology In this type of hydraulic apparatus, the surface of the cylinder facing the swash plate is formed into a conical surface inclined toward the outer periphery of the cylinder in a direction away from the swash plate, so that the cylinder and the swash plate are close to each other. The arrangement and further the compactness of the device are conventionally known (see, for example, Japanese Patent Publication No. 34-3839).

(3) Problem to be Solved by the Invention In such a conventionally known hydraulic device, a receiving member in which spherical ends of each plunger are swingably connected via a spherical joint is slid on a flat inclined surface of a swash plate. Since the plunger spherical end is supported by the swash plate by freely contacting it,
Each plunger receives a large bending moment due to an obliquely outward reaction force from the swash plate (that is, a reaction force having a component away from the cylinder rotation axis), particularly when the plunger is maximally protruded from the cylinder. Sliding resistance increases, which is a major cause of power loss.

The present invention has been made in view of the above circumstances, and can reduce the bending moment that the plunger receives by the reaction force of the swash plate at the time of maximum projection of the plunger from the cylinder, and the compact compact swash plate hydraulic device. The purpose is to provide.

B. Configuration of the Invention (1) Means for Solving the Problems In order to achieve the above object, the present invention provides a cylinder having a large number of cylinder holes arranged in an annular shape in parallel with and surrounding the rotation axis. A large number of plungers that are slidably fitted in the cylinder holes and have spherical end portions that project from one end surface of the cylinder; and are arranged so as to be rotatable relative to the cylinder, facing the tips of these plungers. A swash plate holder; and a swash plate that is rotatably supported by the swash plate holder and contacts the spherical ends of the plungers. The surface facing the swash plate of the cylinder is inclined toward the outer circumference of the cylinder. In a swash plate type hydraulic device formed in a conical surface inclined in a direction away from the plate, the swash plate is provided with a large number of spherical recesses engaging with the spherical ends of the plungers, and the spherical recesses are displaced relative to the swash plate. Provided not to Reaction force applied to the plunger swash plate, so as to have a component directed to the axis of rotation of the cylinder at the maximum projecting from the cylinder of the plunger, characterized in that setting the internal surface shape of each spherical recess.

(2) Action Since the surface of the cylinder facing the swash plate is a conical surface,
The half of the plunger closer to the cylinder rotation axis (that is, the half on the inner side in the radial direction with respect to the cylinder rotation axis) is farther from the rotation axis (that is, the half with respect to the cylinder rotation axis in the radial direction). The amount of protrusion from the cylinder is smaller than that of the outer half). In addition, at the maximum protrusion of each plunger from the cylinder, the reaction force exerted on the spherical end of the sphere of the swash plate has a component directed in the direction of the axis of rotation of the cylinder. Since it is directed to the part (that is, the half part near the cylinder rotation axis), the bending moment of the plunger due to the reaction force becomes relatively small, and the sliding resistance of the plunger due to the bending moment is effectively reduced. .

(3) Example An example of the present invention will be described below with reference to the drawings. In FIG. 1, the power of the engine of the motorcycle is
It is transmitted from the crankshaft 1 to a rear wheel (not shown) through a chain type primary reduction gear 2, a hydrostatic continuously variable transmission T, and a chain type secondary reduction gear 3 in sequence.

The continuously variable transmission T comprises a swash plate hydraulic pump P having a constant capacity, a swash plate hydraulic motor M having a variable capacity, and a crankshaft 1
The crankcase 4 supporting the above is used as a casing and accommodated therein.

The hydraulic pump P is an output sprocket 2a of the primary speed reducer 2.
A cup-shaped input member 5 integrally provided with a pump cylinder 7, a pump cylinder 7 that is rotatably fitted to an inner peripheral wall of the input member 5 via a needle bearing 6, and a center of rotation of the pump cylinder 7 is surrounded by the pump cylinder 7. , Which are slidably fitted in a plurality of odd-numbered cylinder holes 8, 8 ... of an annular array, respectively, and these pump plungers 9, 9
And a pump swash plate 10 that abuts the outer end of.

The pump swash plate 10 is integrally formed on the end wall of the cup-shaped input member 5 and is rotatably supported at its back surface via a thrust roller bearing 11 on a swash plate holder 5a that is inclined at an angle to the axis of the pump cylinder 7. During the rotation of the input member 5, the pump plungers 9, 9, ... Can be reciprocated to repeat the suction and discharge strokes.

In order to improve the followability of the pump plunger 9 with respect to the pump swash plate 10, a spring for urging the pump plunger 9 in the extension direction may be contracted in the cylinder hole 8.

The rear surface of the input member 5 is a thrust roller bearing 12
Is supported by the support cylinder 13 via.

On the other hand, the hydraulic motor M includes a motor cylinder 17 coaxially arranged to the left of the pump cylinder 7, and a plurality of odd-numbered cylinder holes arranged in an annular array in the motor cylinder 17 so as to surround the rotation center. The motor plungers 19, 19 ... which are respectively slidably engaged with 18, 18, ..., the motor swash plate 20 which abuts on the outer ends of these motor plungers 19, 19 ..., and the back and outer peripheral surfaces of the motor swash plate 20 are thrust roller bearings. It comprises a swash plate holder 22 supported via 21 and a cup-shaped swash plate anchor 23 supporting the swash plate holder 22.

The motor swash plate 20 can tilt between an upright position that is perpendicular to the axis of the motor cylinder 17 and a tilted position that tilts at a certain angle. At that tilted position, the motor cylinder 17 rotates. Accordingly, the motor plungers 19, 19 ... Can be reciprocated to repeat the expansion and contraction strokes.

In order to improve the followability of the motor plunger 19 with respect to the motor swash plate 20, a spring that biases the motor plunger 19 in the extension direction may be contracted in the cylinder hole 18.

Between the pump cylinder 7 and the motor cylinder 17, first and second valve discs 14, 15 are interposed in order from the pump cylinder 7 side, and the output shaft 25 is provided at the center of these four discs 7, 14, 15, 17. Penetrate. A flange 25 integrally formed on the outer periphery of the output shaft 25
By hitting the outer end of the motor cylinder 17 against a and tightening the outer end of the pump cylinder 7 with the nut 26 that is screwed onto the output shaft 25, the four members 7, 14, 15, 17 are superposed and bonded to each other. And is fixed to the output shaft 25.

At that time, as shown in FIG. 1A, in order to ensure the connection of the four members 7, 14, 15, 17 with the output shaft 25, and to define their mutual position, the output power of each cylinder 7, 17 is increased. Key between axis 25
16, 16 are mounted, and the pump cylinder 7 and the first valve disc 14,
Between the motor cylinder 17 and the second valve disc 15, knock pins 24, 2
4 is inserted.

Referring again to FIG. 1, the output shaft 25 also penetrates the input member 5 and rotatably supports the member 5 via a needle bearing 27.

The support cylinder 13 is fitted on the outer periphery of the right end portion of the output shaft 25 via a key 28, and is fixed by a nut 30. Above support tube
The right end of the output shaft is rotatably supported by the crankcase 4 via the roller bearing 13 and the roller bearing 31.

Further, the output shaft 25 penetrates through the central portions of the motor swash plate 20, the swash plate holder 22, and the swash plate anchor 23, and supports the back surface of the swash plate anchor 23 at its left end via a thrust roller bearing 32. The support cylinder 33 is spline-fitted and fixed with the nut 34 together with the input sprocket 3a of the secondary speed reducer 3. The left end of the output shaft 25 is freely rotatable with the crankcase 4 through the support cylinder 33 and the roller bearing 35. Supported by.

A hemispherical centering body 36 that slidably engages with the inner peripheral surface of the pump swash plate 10 in all directions is slidably fitted to the output shaft 25. The aligning body 36 includes a plurality of disc springs 38.
Force presses the pump swash plate 10 against the thrust roller bearing 11, whereby the pump swash plate 10 is always aligned.

Further, a hemispherical centering body 37 that slidably engages with the inner peripheral surface of the motor swash plate 20 in all directions is slidably fitted to the output shaft 25. The aligning body 37 moves the motor swash plate 20 to the thrust roller bearing 21 by the force of a plurality of disc springs 39.
The swash plate 20 is constantly pressed against the swash plate 20.

The tips of the pump and motor plungers 9,9 ...; 19,19 ... are formed into spherical end portions 9a, 9a ...; 19a, 19a ..., which are in an annular arrangement formed on the pump and motor swash plates 10,20. ..; 20a, 20a ... Are engaged with a large number of spherical recesses 10a, 10a. The spherical recesses 10a, 10a ...; 20a, 20a ... are ensured to be properly engaged with the spherical end portions 9a, 9a ...; 19a, 19a ... at any rotational position of the swash plates 10, 20. In addition, the radius of curvature of each spherical concave portion 10a, 20a is set larger than that of the corresponding spherical end portion 9a, 19a.

More specifically, the engagement points between the spherical concave portions 10a, 10a ...; 20a, 20a ... And the spherical end portions 9a, a ...; 19a, 19a ... are in the inclined state of the pump swash plate 10 and the motor swash plate 20. , Its spherical recess 10a, 10a
..; 20a, 20a .., slightly move as the pump cylinder 7 and the motor cylinder 17 rotate. That is, the engagement point is the maximum when the plungers 9 and 19 come from the cylinder holes 8 and 18.
When the minimum protrusion state (state of Fig. 1), the plunger
When it occupies the outermost position radially outward of the axis of rotation of the cylinders 7,17 with respect to the axis of 9,19, and when the plungers 9,19 come to the midpoint of their stroke (state in FIG. 2), It occupies the innermost position inward in the radial direction with respect to the rotation axis of the cylinder 7, 17 with respect to the axis of the plunger 9, 19.
With the rotation of 7,17, it reciprocates between the outermost position and the innermost position.

Therefore, when the plungers 9 and 19 are in the maximum / minimum protruding state, the plungers 9 and 19 are not attached to the pump swash plate 10 or motor swash plate.
The reaction force received from 20 is directed in the rotation axis direction of the cylinders 7, 17.

The end surface of the motor cylinder 17 that faces the motor swash plate 20 is formed as a conical surface 17a that is inclined toward the outer periphery of the motor cylinder 17 and away from the motor swash plate 20, and the motor swash plate 20 has its maximum inclination. At this time, it is arranged so as to be as close as possible to a part of the conical surface 17a.

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

The second valve disc 14 is provided with an annular low pressure oil passage 41 and an annular high pressure oil passage 40 surrounding the annular low pressure oil passage 41. From the low pressure oil passage 41 to the cylinder holes 8, 8 of the pump cylinder 7 in one direction. Intake valves 43, 43 ... Allowing the flow of hydraulic oil, and pump cylinder 7
A discharge valve 42 that allows the flow of hydraulic oil in one direction from the cylinders 8, 8, ... To the high-pressure oil passage 40 is provided in the first valve disk 14. Therefore, the numbers of the suction valves 43 and the discharge valves 42 are the same as the number of the pump plungers 9, 9 ,.

Further, the second valve board 15 is provided with distribution valves 44, 44 ... Which alternately control the high pressure and low pressure oil passages 40, 41 to communicate with the cylinder holes 18, 18 of the motor cylinder 17. Therefore, the distribution valve 44
Is the same as the number of motor plungers 19, 19.

The distribution valves 44, 44 ... Are of the spool type, and the motor cylinder 1
Between the group of cylinder holes 18, 18 of 7 and the high and low pressure oil passages 40, 41 are slidably fitted into valve holes 45, 45 ... Radially formed in the second valve disc 15. Further, in the second valve disc 15, the first and second ports a, which communicate between the valve holes 45 and the high pressure and low pressure oil passages 40, 41, respectively.
b, each valve hole 45 and the motor cylinder 17 adjacent to it
A third port c communicating with the cylinder hole 18 is formed. When the distribution valve 44 occupies the position radially outward of the valve hole 45, the corresponding third port c is in communication with the first port a and is in communication with the second port b, and the corresponding cylinder hole is formed. 19 is communicated with the high pressure oil passage 40. When the valve hole 45 is located radially inward, the corresponding third port c is moved to the second position.
It communicates with port b and disconnects with the first port a,
The corresponding cylinder hole 19 communicates with the low pressure oil passage 41.

As shown in FIGS. 1 and 3, an eccentric wheel 47 is provided so as to surround the distribution valves 44, 44 ... Group so as to control the operation of the distribution valves 44, 44. , So that the outer end of each distribution valve 44 is engaged with the inner peripheral surface of the eccentric wheel 47, the discharge pressure of the replenishment pump 67 is operating on the inner end surface of each distribution valve 44 through a first oil supply hole 72 described later. Always acted on.

The eccentric wheel 47 is composed of an inner ring of a ball bearing 48 fitted in the crankcase 4, and, as shown in FIG. 3, in the direction of the tilt axis O of the motor swash plate 20, the motor cylinder.
It is installed at a position eccentric from the center of 17 by a certain distance. Therefore, when the motor cylinder 17 rotates, each distribution valve 44
Reciprocates between the outer position and the inner position in the valve hole 45 with a stroke that is twice the eccentricity ε of the eccentric wheel 47.

At both ends of the swash plate holder 22, a pair of trunnion shafts 80, 80 'aligned on the tilt axis O of the motor swash plate 20 are bored at one end, and these trunnion shafts 80, 80' are provided with needle bearings 81 therebetween. Rotatably supported by the swash plate anchor 23. In other words, the tilt axis O is defined by the trunnion shafts 80 and 80 '.

An operating lever 82 is fixedly attached to the outer end of one trunnion shaft 80. Thus, when the trunnion shaft 80 is rotated by the operating lever 82, the swash plate holder 22 integrated with it is also rotated, and the swash plate holder 20 can be freely tilted even while the motor swash plate 20 is rotating.

The swash plate 23 is supported on the outer periphery of the motor cylinder 17 via a needle bearing 78, and is connected to the crankcase 4 via a pair of positioning pins 49, 49 so as not to rotate around the output shaft 25. .

In the above configuration, when the input member 5 of the hydraulic pump P is rotated from the primary reduction gear device 2, the pump swash plate 10 alternately applies suction and discharge strokes to the pump plungers 9, 9. Then, each pump plunger 9 sucks the working oil from the low pressure oil passage 41 when performing the suction stroke, and feeds the high pressure working oil to the high pressure oil passage 40 when performing the discharge stroke.

The high-pressure hydraulic oil sent to the high-pressure oil passage 40 is fed to the cylinder hole 18 accommodating the motor plunger 19 in the expansion stroke via the distribution valve 44 at the outer position, while the motor plunger 19 in the contraction stroke is supplied. The hydraulic oil in the cylinder hole 18 to be stored is discharged to the low pressure oil passage 41 via the distribution valve 44 at the inner position.

During this time, the reaction torque that the pump cylinder 7 receives from the pump swash plate 10 via the pump plunger 9 in the discharge stroke,
The pump cylinder 7 and the motor cylinder 17 are rotated by the sum of the reaction torque that the motor cylinder 17 receives from the motor swash plate 20 via the motor plunger 19 in the expansion stroke, and the rotation torque is secondary decelerated from the output shaft 25. It is transmitted to the device 3.

In this case, the gear ratio of the output shaft 25 to the input member 5 is given by the following equation.

Therefore, if the capacity of the hydraulic motor M is changed from zero to a certain value, the gear ratio can be changed from 1 to a certain required value.

By the way, since the capacity of the hydraulic motor M is determined by the stroke of the motor plunger 19, the gear ratio is continuously controlled from 1 to a certain value by tilting the motor swash plate 20 from the upright position to a certain tilt position. be able to.

During such operation of the hydraulic pump P and the hydraulic motor M, the pump swash plate 10 receives thrust loads from the pump plungers 9, 9 ... Group, and the motor swash plate 20 receives thrust loads in the opposite directions from the motor plungers 19, 19 ... Group. However, the thrust load received by the pump swash plate 10 is supported by the output shaft 25 via the thrust roller bearing 11, the input member 5, the thrust roller bearing 12, the support cylinder 13 and the nut 30, and the thrust load received by the motor swash plate 20. Is thrust roller bearing 21, swash plate holder 22, swash plate anchor 23, thrust roller bearing
It is also supported by the output shaft 25 via the support tube 33, the support tube 33, the sprocket 3a and the nut 34. Therefore, the thrust load causes only a tensile stress on the output shaft 25, and
It has no effect on the crankcase 4 supporting the 25.

Further, the pump and motor swash plates 10 and 20 and the pump and motor plungers 9, 9 ...; 19, 19 ... Group are spherical recesses 10a, 10a.
Since the 0a, 20a, ... Are engaged with the spherical end portions 9a, 9a ..; 19a, 19a .. When the pump and motor cylinders 7 and 17 are rotated relative to the pump and motor swash plates 10 and 20, each swash plate 10 and
20 rotates synchronously with each of the cylinders 7 and 17 via the opposite plunger group. Furthermore, the spherical recesses 10a, 10a ...
20a, 20a ... And the spherical end portions 9a, 9a ...; 19a, 19a ... Cooperate with the swash plates 10, 20 from the plungers 9, 9 ,. On the other hand, most of the component force of the pressing force exerted by the spherical end portions 9a, 19a on the bottom surfaces of the spherical concave portions 10a, 20a is directed inward or outward in the radial direction of the cylinders 7, 17 about the output shaft 25. , These component forces become the centering force, and the swash plate 10,2
Try to hold 0 in the regular position.

Further, in the hydraulic motor M, the end surface of the motor cylinder 17 facing the motor swash plate 20 is formed into the conical surface 17a, so that the half portion of the motor plunger 19 near the motor cylinder rotation axis (that is, the rotation axis of the motor cylinder 17). The inner half in the radial direction with respect to the motor is more than the half farther from the group than the rotational axis (that is, the outer half in the radial direction with respect to the rotation axis of the motor cylinder 17). The amount of protrusion from the cylinder 17 is reduced. In addition, at the time of maximum protrusion from the cylinder hole 18 of the motor plunger 19, that is, at the end of the expansion stroke,
The engagement point between the spherical end portion 19a of the plunger 19 and the spherical concave portion 20a of the motor swash plate 20 is at the outermost position, and the reaction force received by the plunger 19 from the motor swash plate 20 is the rotation axis of the motor cylinder 17. Since it has a component directed in the direction and is directed toward the motor plunger half part (that is, the half part closer to the cylinder rotation axis) from the cylinder 17 where the amount of protrusion is small, even when the motor plunger 19 is maximally protruding, The bending moment applied to the plunger 19 by the force is relatively small. Therefore, the sliding resistance of the motor plunger 19 and the motor cylinder 17 is relatively small.

Also in the hydraulic pump P, if the surface of the pump cylinder 7 facing the pump swash plate 10 is formed into a conical surface, and the spherical recess 10a of the pump swash plate 10 is formed in the same manner as the spherical recess 20a of the motor swash plate 20, It is possible to reduce the bending moment when the pump plunger 9 is maximally projected.

Referring again to FIG. 1, the second valve disc 15 is further provided with one or a plurality of clutch valves 50 capable of communicating between the high and low pressure oil passages 40 and 41 in a timely manner. This clutch valve 50 is
Through the high-pressure oil passage 40 and is slidably fitted into a radial valve hole 51 that opens to the outer periphery of the second valve disc 15. The clutch valve 50 is provided with a vertical hole 52 opening on the inner end surface thereof and a horizontal hole 53 intersecting with the vertical hole 52 and opening on the outer peripheral surface of the clutch valve 50. Radius method of hole 81 When it occupies the inner position (clutch on position) of the hole 81, it is closed by the inner wall of the lateral hole 51, and when it occupies the radially outer position (clutch off position), the lateral hole 53 opens to the high pressure oil passage 40. It is like this.

The clutch valve 50 receives the hydraulic pressure of the low-pressure oil passage 40 at its inner end so as to be biased to the clutch-off position side, and has its outer end at the pump cylinder 7 and the first and second valve discs 14, 15. A clutch control ring 54 slidably fitted on the outer periphery is engaged.

The clutch control ring 54 has a cylindrical inner peripheral surface 54a that defines the clutch on position of the clutch valve 50, and a tapered surface 54b that is continuous with one end of the inner peripheral surface and defines the clutch off position of the clutch valve 50, and A spring 55 urges the clutch valve 50 to the side that holds the clutch on position. The spring 55 is contracted between the clutch control ring 54 and the retainer 56 locked to the outer circumference of the pump cylinder 7.

As shown in FIG. 2, the clutch control ring 54 is connected to a clutch lever (not shown) via a shift fork 57, an intermediate lever 58 and a clutch wire 59. Shift fork
The base end of the 57 is pivotally supported 60 on the crankcase 4, the middle part is engaged with the side surface of the flange 54c of the clutch control ring 54, and the front end is connected to the middle lever 58 via the push rod 61. To be done.

By pulling the clutch wire 59, the clutch control ring 54 is moved rightward in FIG. 1 through the shift fork 57 against the force of the spring 55. Is opposed to the clutch valve 50, the clutch valve 5
0 is moved to the outer position, that is, the crack-off position by the pressure of the low pressure oil passage 40. As a result, the high-pressure oil passage 40 is short-circuited to the low-pressure oil passage 41 via the vertical hole 52 and the horizontal hole 53 of the clutch valve 50, so that the pressure of the high-pressure oil passage 40 decreases and the supply of the pressure oil to the hydraulic motor M is reduced. The hydraulic motor M can be deactivated by disabling the feeding.

Further, when the clutch control ring 54 is moved to the left by the elastic force of the spring 55 to operate the clutch valve 50 to the clutch on position, the lateral hole 53 of the clutch valve 50 is closed by the inner wall of the valve hole 51, so that the high pressure And the low-pressure oil passages 40, 41 are cut off, and the hydraulic oil P is circulated through the oil passages 40, 41 between the hydraulic pump P and the hydraulic motor M as described above to return the hydraulic motor M to the operating state. You can In this case, the operation of the clutch valve 50 to the clutch-on position is performed against the hydraulic pressure of the low-pressure oil passage 41 that acts on the inner end surface of the clutch valve 50, so that the spring of the spring 55 that moves the clutch control ring 54 to the left is elastic. The force generated can be set relatively weak, and the operation force of the clutch control ring 54 can be reduced.

At the intermediate position between the right and left moving positions of the clutch control ring 54, the opening of the lateral hole 53 of the clutch valve 50 is appropriately throttled (see FIG. 1B), and the hydraulic pump P is adjusted according to the opening. Since the hydraulic oil is circulated between the hydraulic motor M and the hydraulic motor M, the hydraulic motor M can be in a half-clutch state. In this case, since the opening degree of the lateral hole 53 gradually increases or decreases as the clutch valve 50 moves, a half-clutch state can be easily obtained, and smooth transient operation can be performed.

Referring again to FIGS. 1 and 2, the output shaft 25 is provided with an oil passage 63 having a deep stop at the center thereof, and an open end of the oil passage 63 is provided with an open end of the clutch case 4. The oil supply pipe 64 supported by the side wall is inserted. The oil supply pipe 64 communicates with the inside of an oil pan 69 at the bottom of the crankcase 4 via an oil passage 63 formed in the side wall of the crankcase 4, a filter 66 mounted on the side wall, a replenishment pump 67 and a strainer 68. ,
The replenishment pump 67 is driven from the input member 5 via gears 70 and 71. Therefore, the oil in the oil pan 69 is constantly supplied to the oil passage 63 by the replenishment pump 67 while the input member 5 is rotating.

The output shaft 25 also has one or more first oil supply holes 72 extending radially from the oil passage 63 toward the valve hole 45 of the distribution valve 44.
And an annular groove 73 that communicates the first oil supply hole 72 with the valve holes 45, 45 ... Group, and when the distribution valve 44 comes to a position outside the valve hole 45, the second oil flow passage 41 connects with the low pressure oil passage 41. Valve hole 45 for pump b
It communicates with the first oil supply hole 72 via. Therefore, if the hydraulic oil leaks from the hydraulic closed circuit between the hydraulic pump P and the hydraulic motor M, when the distribution valve 44 comes to the position outside the valve hole 45, the hydraulic oil flows from the first oil supply hole 72 to the low pressure oil passage 41. Is replenished.

The output shaft 25 is further provided with a second oil supply hole 74 that extends radially from the oil passage 63 and opens inside the cup-shaped input member 5, and a cup-shaped wheel plate anchor that also extends radially from the oil passage 63. twenty three
And a third oil supply hole 75 that opens inside the oil supply hole, and orifices 76 and 77 are provided in these oil supply holes 74 and 75, respectively.
With these orifices 76 and 77, a replenishment pump 67
While reliably supplying the hydraulic oil from the first oil supply hole 72 to the low pressure oil passage 41 while maintaining the discharge pressure thereof, and supplying an appropriate amount of lubricating oil from the oil passage 63 into the input member 5 and the inside of the vehicle plate anchor 23. be able to.

The oil supplied to the inside of the input member 5 lubricates the aligning body 36, the pump swash plate 10, the pump plunger 9, ..., The thrust roller bearing 11, the needle bearing 6 and the like, and is also supplied to the inside of the swash plate anchor 22. Oil is aligned body 37, motor swash plate 2
Lubricate 0, motor plunger 19 and thrust bearing 21. In this case, since the pump cylinder 7 is fitted to the open end of the cup-shaped input member 5 via the needle bearing 6, a large amount of lubricating oil is retained in the input member 5. On the other hand, since the motor cylinder 17 is fitted to the open end of the swash plate anchor 23 via the needle bearing 78,
A large amount of lubricating oil is also retained in the swash plate anchor 23.

Further, for further lubrication of the sliding surface of the pump plunger 9 and the inside of the input member 5, a thin oil hole 112 communicating between the inside and outside of the pump plunger 9 is bored, and the sliding surface of the motor plunger 9 and the slanted surface To further lubricate the inside of the plate anchor 23, the motor plunger 19 is provided with a thin oil hole 113 that communicates the inside and outside thereof.

In FIGS. 2, 4, and 5, the motor swash plate 20 is used.
For operating the tilting operation of the trunnion shaft 80.
A shift control device 83 is connected to 82.

The shift control device 83 includes a cylinder 84 fixed to the crankcase 4 and a piston 85 slidably fitted on the cylinder 84. There is a window 86 on the side wall of the cylinder 84 and a piston 85.
A connecting member 87 is formed in the central portion of the trunnion shaft 80 such that the connecting member 87 penetrates it laterally and faces the window 86, and the operating lever 82 of the trunnion shaft 80 is engaged with the connecting hole 87 through the window 86. The piston 85 can be slid according to the rotation of the trunnion shaft 80.

In FIG. 4, the actuating lever 82 and thus the piston 85
The leftward movement of the swash plate 20 causes the motor swash plate 20 to stand upright.
An oil chamber 88 is defined, and a second oil chamber 89 is defined between the piston 85 and the right end wall of the cylinder 84. The first oil chamber 88 is returned to urge the piston 85 toward the second oil chamber 89. The spring 90 is retracted.

The first and second oil chambers 88 and 89 are communicated with each other via a hydraulic conduit 92 in which a shift control valve 91 is interposed, and the inside thereof is filled with hydraulic oil.

The shift control valve 91 is installed in a proper position of a vehicle control device and intervenes in the middle of the hydraulic conduit 92, and the first and first serially installed oil passages 94 in the valve box 93. 2 Check valves 95,96
Composed of and. These first and second check valves 95, 96
Are arranged so that their forward directions are opposite to each other, and
The valve springs 97 and 98 are always biased in the valve closing direction.

First and second check valves 95 and 96 are connected to first and second valve rods 100 and 101, respectively, which can respond to the valve opening direction. In addition, the first and second valve opening rods 100 and 101 are
Seesaw type gearshift lever 102 pivotally supported by 3
Are connected to the lower surfaces of both left and right ends of the.

The gear shift lever 102 is operated by the operator to a horizontal hold position A, a deceleration position B that swings to the left, and an acceleration position C that swings to the right. Double check valve at the hold position A
Keep the valve closed at 95 and 96, and at the deceleration position B, open the first valve rod 100
The first check valve 95 can be forcibly opened by pushing down, and the second check valve 96 can be forcibly opened by pushing down the second valve opening 101 at the speed increasing position C.

By the way, since the number of the motor plungers 19, 19 ... Is an odd number, the thrust load exerted on the motor swash plate 20 by the motor plungers 19, 19 ... Group during the rotation of the motor cylinder 17 is the tilt axis O of the motor swash plate 20. The strength changes alternately between the one side and the other side with the boundary as a boundary, and a vibrational tilting torque acts on the motor swash plate 20. Then, this oscillatory tilting torque acts on the piston 85 via the actuating lever 82 alternately as a pressing force in the left-right direction.

Therefore, if the shift lever 102 is shifted to the speed increasing position C,
Since the second check valve 96 is opened, the first check valve 95 allows the flow of oil from the first oil chamber 88 to the second oil chamber 89, but flows in the opposite direction. Is blocked and the operating lever
Oil flows from the first oil chamber 88 to the second oil chamber 89 only when a leftward pressing force acts on the piston 85 from 82. As a result, the piston 85 moves to the first oil chamber 88 side, and the operating lever 82
Is rotated in the standing direction of the motor swash plate 20.

Next, when the shift lever 102 is shifted to the deceleration position B, the first check valve 95 is opened this time, so the second check valve 96 is opened.
By this, the flow of oil from the second oil chamber 89 to the first oil chamber 88 is allowed, but the flow in the opposite direction is blocked, and only when the rightward pressing force of the piston 85 from the operating lever 82 acts. Oil flows from the second oil chamber 89 to the first oil chamber 88. As a result, the piston 85 moves to the second oil chamber 89 side, and the operating lever 82
Is rotated in the inclination direction of the motor swash plate 20.

When the speed change lever 102 is returned to the hold position A, the check valves 95 and 96 that are closed close to each other to completely block the flow of oil in the valve box 93, so that the piston 85 cannot move. Become,
Hold the operating lever 82 at that position, and
Can be fixed in an upright or tilted position.

Further, if the transmission lever 102 is shifted to the deceleration position B and the first check valve 95 is opened in the stopped state of the transmission T, the oil flow from the second oil chamber 89 to the first oil chamber 88 will occur. Therefore, even if the piston 85 is in the left movement position, it can be moved to the right movement limit by the elastic force of the return spring 90, and the actuation lever 82 can be rotated to the maximum tilt position of the motor swash plate 20. .

As shown in FIG. 5, the cylinder 84 is arranged at a right angle to or near the axis of the output shaft 25. In this way, when the operating lever 82 pushes the piston 85,
It is possible to prevent the reaction force from acting on the swash plate anchor 23 via the trunnion shaft 80 in the axial direction of the output shaft 25.

In FIG. 4, a reserve tank 109 is installed above the cylinder 84, and the reserve tank 109 is installed in the cylinder 84.
Relief port 110 and supply port 111 communicating inside
Are drilled in the upper wall of the cylinder 84.

Cylinder 84 is attached to the outer periphery of the left and right ends of piston 85.
The first and second cup seals 105, 106 having a one-way sealing function that are in close contact with the inner peripheral surface of the cylinder are mounted, and the cylinder 84
O-rings 107, 108 that are in close contact with the outer peripheral surface of the intermediate portion of the piston 85 are mounted on the inner periphery of the left and right sides of the window 86.

Thus, the relief port 110 opens to the first hydraulic chamber 88 immediately before the first cup seal 105 when the piston 85 is located in the right limit, and the supply port 111 always keeps the second cup seal 106 and the O-ring. It is adapted to open to the inner surface of the cylinder 84 with respect to 108.

Therefore, when the piston 85 is located in the right limit, when the pressure rises in the first oil chamber 88 due to the rise of the oil temperature or the like, the pressure is released from the relief port 110 to the reserve tank 109. Further, when the piston 85 moves to the left, the first oil chamber 88 is pressurized by the piston 85 from the time when the first cup seal 105 passes through the opening of the relief port 110, and the first oil chamber 88 moves to the second oil chamber 89. Allows oil flow. At that time, the second
If the hydraulic chamber 89 is decompressed below a specified pressure, the reserve tank
Due to the pressure difference between 109 and the second oil chamber 89, the reserve tank 1
The oil inside 09 passes through the sliding gap between the cylinder 84 and the piston 85 from the supply port 111, and the second cup seal 106
The oil is supplied to the chamber 89 while being bent toward the oil chamber 89.

If the inside of the reserve tank 109 is kept at a high pressure, the hydraulic conduit 92 is pretensioned by the hydraulic pressure, so that the hydraulic conduit 92 is not affected by the change in the hydraulic pressure due to the operation of the piston 25.
The rigidity of 92 is enhanced, and the operation of the piston 85 can be stabilized.

C. Effects of the Invention As described above, according to the present invention, since the surface of the cylinder facing the swash plate is a conical surface, the half of the plunger closer to the cylinder rotation axis (that is, the diameter relative to the cylinder rotation axis) The inner half of the direction) has a smaller amount of protrusion from the cylinder than the half farther from the rotation axis (that is, the half on the outer side in the radial direction with respect to the rotation axis of the cylinder). Moreover, at the time of maximum protrusion of each plunger from the cylinder, the reaction force exerted on the plunger spherical end of the swash plate spherical recess has a component directed in the direction of the axis of rotation of the cylinder, and the plunger half (the amount of protrusion from the cylinder is small). That is, since the bending moment of the plunger due to the reaction force is relatively small, the sliding resistance of the plunger due to the bending moment is effective. It is reduced, which contributes greatly to the improvement of the transmission efficiency.

[Brief description of drawings]

The drawings show one embodiment of the present invention. FIG. 1 is a longitudinal sectional view of a hydrostatic continuously variable transmission interposed in a power transmission system of a motorcycle, and FIG. 1A is a pump cylinder in FIG. , Motor cylinder, first and second valve disk and output shaft assembly longitudinal sectional view, 1B
1 is an operational view of the clutch valve in FIG. 1, FIG. 2 is a partially longitudinal rear view of the continuously variable transmission, FIG. 3 is a sectional view taken along the line III-III of FIG. 1, and FIG. FIG. 5 is a sectional view taken along the line IV-IV of FIG. 5, and FIG. 5 is a plan view of the continuously variable transmission. 17 …… Cylinder, 17a …… Conical surface, 18 …… Cylinder hole, 1
9 ... Plunger, 19a ... Spherical end, 20 ... Swash plate, 20a
...... Spherical recess, 22 swash plate holder, 23 swash plate anchor

Claims (1)

[Claims] 1. A cylinder (17) having a large number of cylinder holes (18) arranged in parallel with and surrounding the axis of rotation and annularly surrounding the axis; and slidably fitted in the cylinder holes (18). In addition, a large number of plungers (19) having spherical end portions (19a) protruding from one end surface of the cylinder (17); arranged so as to face the tips of these plungers (19) and relatively rotatable with the cylinder (17). And a swash plate (20) rotatably supported by the swash plate holder (22) and abutting on the spherical end (19a) of each plunger (19). A swash plate hydraulic system in which the surface of the cylinder (17) facing the swash plate (20) is formed as a conical surface (17a) that is inclined toward the outer circumference of the cylinder (17) and away from the swash plate (20). In the device, the swash plate (20) is provided with a number of spherical recesses (20) that engage with the spherical ends (19a) of the plungers (19). a) to the spherical recess (20a)
To prevent relative displacement with respect to the swash plate (20), and the reaction force applied to the plunger (19) of the swash plate (20) when the cylinder (17) of each plunger (19) is maximally protruding from the cylinder (17). ) The swash plate type hydraulic device is characterized in that the inner surface shape of each spherical concave portion (20a) is set so as to have a component directed to the rotation axis of (1).