JP2631354B2 - Variable displacement hydraulic device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
Cylinder connected to the main shaft supported on the shaft so that it can rotate integrally
And this cylinder is parallel to and around its axis
Around the spindle and the plungers
Swash plate that is arranged at the front and makes the front face abut the outer end of the plunger
Rotate the back of the swash plate around the spindle
And a swash plate holder that supports the swash plate as much as possible.
Tilt around the tilt axis perpendicular to the axis of the spindle
The variable displacement hydraulic device is designed to control the
You.

[0002]

2. Description of the Related Art Such a variable displacement hydraulic device is, for example,
As disclosed in U.S. Patent No. 745,543,
Is known to.

[0003]

By the way, the conventional variable
In a displacement hydraulic system, a truss formed integrally with the swash plate holder
The nonion shaft is rotatably supported on the casing.
During operation, the sludge generated between the cylinder and the plunger
The strike load must be applied to the casing from the trunnion shaft.
The casing must be made thick and rigid.
And this is an obstacle to weight reduction
ing.

[0004] The present invention has been made in view of such circumstances.
Therefore, thrust load generated between cylinder and plunger
Releases the casing from the weight, making it thinner and lighter
The oil that can control the angle of the swash plate without hindrance
It is an object to provide a pressure device.

[0005]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
In the present invention, the cylinder is connected to the main shaft so that it cannot move in the axial direction.
While tilting the back of the swash plate holder around the spindle
The swash plate anchor that is supported on the
Supports relative rotation of members via thrust bearings
The swash plate anchor to the casing so that it cannot rotate.
Stopping is a first feature.

[0006] The present invention also provides, in addition to the above-mentioned features, a syringe
A second feature is that the damper is formed integrally with the main shaft.

[0007]

According to the first aspect of the present invention, the cylinder is mainly used.
The swash plate anchor is mainly connected to the shaft
Through the thrust bearing to the thrust receiving member on the shaft
Generated between cylinder and plunger as it is supported
The thrust load acts on the spindle as a simple tensile load.
And Thus, the thrust load is high in tensile strength
The load on the casing is eliminated because the load is applied to the spindle.
I do.

In addition, the swash plate holder is swingably supported.
The swash plate anchor is simply non-rotatably locked to the casing
Do not apply a thrust load to the casing.
Swash plate holder
The tilt of the damper can always be performed smoothly.

According to a second feature of the present invention, the main shaft and
Cylinder and cylinder integrate the spindle rigidity.
Effectively increase.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, the power of an engine of a motorcycle is transmitted from a crankshaft 1 to a chain-type primary reduction gear 2,
The power is transmitted to a rear wheel (not shown) through a hydrostatic continuously variable transmission T and a chain type secondary reduction gear 3 sequentially.

The continuously variable transmission T comprises a fixed displacement type swash plate type hydraulic pump P and a variable displacement type swash plate type hydraulic motor M, and is accommodated therein with a crankcase 4 supporting the crankshaft 1 as a casing. The hydraulic motor M
The invention applies.

The hydraulic pump P is a cup-shaped input member 5 integrally provided with an output sprocket 2a of the primary reduction gear 2.
A pump cylinder 7 which is rotatably fitted to the inner peripheral wall of the input member 5 via a needle bearing 6;
The pump plungers 9, 9 ... which are respectively slid into a plurality of odd-numbered cylinder holes 8, 8 ... provided in an annular arrangement provided around the center of rotation of the pump cylinder 7, and the outside of the pump plungers 9, 9 ... And a pump swash plate 10 in contact with the end.

The back surface of the pump swash plate 10 is rotatably supported on the inner end wall of the input member 5 via a thrust roller bearing 11 in a posture inclined at a predetermined angle with respect to the axis of the pump cylinder 7. .. Can be reciprocated to repeat the suction and discharge strokes.

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

On the other hand, the hydraulic motor M is provided with a pump cylinder 7
A motor cylinder 17 which is coaxially and tightly connected to the shaft, a support shaft 24 and an output shaft 2 which are integrally formed at the center portions of both outer end surfaces of the motor cylinder 17 and extend in the axial direction.
5, an annular array of a plurality of and odd-numbered cylinder holes 18 provided around the rotation center of the motor cylinder 17;
Motor plungers 19, 1 respectively slid on
, A swash plate 20 for contacting the outer ends of the motor plungers 19, 19, a swash plate holder 22 for supporting the rear surface of the motor swash plate 20 via a thrust roller bearing 21, And a swash plate anchor 23 that supports the rear surface of the holder 22.

The motor swash plate 20 can be tilted between an upright position perpendicular to the axis of the motor cylinder 17 and an inclined position inclined at a certain angle. The reciprocating motion is given to the motor plungers 19 with the rotation of the motor 17 so that the expansion and contraction processes can be repeated.

The support shaft 24 passes through the center of the pump cylinder 7, and the pump cylinder 7 and the motor cylinder 17 are integrally connected to each other by screwing a nut 26 to the center. The support shaft 24 also penetrates the input member 5 and rotatably supports the member 5 via a needle bearing 27.

The support shaft 13 is spline-fitted to the outer periphery of the support shaft 24, and is fixed by a nut 30. The support shaft 24 is rotatably supported by the crankcase 4 via the support cylinder 13 and the roller bearing 31.

The output shaft 25 passes through the center of the motor swash plate 20, the swash plate holder 22, and the swash plate anchor 23, and the end of the output shaft 25 is connected to the back surface of the swash plate anchor 23 through a thrust roller bearing 32. A support cylinder 33 as a thrust receiving member to be supported is spline-fitted, and is fixed together with an input sprocket 3a of the secondary reduction gear 3 by a nut 34, and an output shaft is provided via the support cylinder 33 and the roller bearing 35. 25 is rotatably supported by the crankcase 4.

A spherical spline member 36 is fixedly mounted on the support shaft 24 so as to be able to incline in all directions relative to the inner peripheral surface of the pump swash plate 10. The output shaft 25 is provided with a motor swash plate. A spherical spline member 37 which is spline-engaged relative to the inner peripheral surface of the base member 20 so as to be tiltable in all directions is fixed. Thereby, sliding between the pump plungers 9, 9... And the pump swash plate 10, and the motor plungers 19, 19.

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

The motor cylinder 17 has an annular high-pressure oil passage 4 between a group of cylinder holes 8 of the motor cylinder 17 and a group of cylinder holes 18 of the pump cylinder 7.
0, and an annular low-pressure oil passage 41 surrounding the same, and the high-pressure oil passage 40 is provided in the cylinder hole 8 of the pump cylinder 7,
8 are communicated via discharge valves 42, 42, respectively.
The low-pressure oil passage 41 is also connected to the cylinder holes 8, 8 via suction valves 43, 43, respectively. Accordingly, the discharge valves 42 and the suction valves 43 are provided in the same number as the pump plungers 9, 9, respectively.

The high and low pressure oil passages 40 and 41 are
.. Are connected to each other via distribution valves 44, 44,. Therefore, the same number of distribution valves 44 as the number of motor plungers 19 are provided.

The distribution valves 44, 44 are of a spool type and have a group of cylinder holes 18, 18,.
Valve hole 4 radially provided in motor cylinder 17 between
5, 45... And occupy a radially inward position of the valve hole 45 and the corresponding cylinder hole 18 and high-pressure oil passage 40.
And cut off between the low-pressure oil passage 41 and
When the valve hole 45 occupies a radially outer position, the valve hole 45 communicates with the corresponding cylinder hole 18 and the low-pressure oil passage 41 and shuts off the high-pressure oil passage 40.

In order to control these distribution valves 44, 44,.
The valve holes 45, 45 ... accommodate therein valve springs 46, 46 ... for urging the distribution valves 44, 44 ... radially outward.
The inner peripheral surface of the eccentric ring 47 is engaged with the outer end of each distribution valve 44.

The eccentric wheel 47 is constituted by an inner ring of a ball bearing 48 fitted to the crankcase 4, and as shown in FIG. 2, from the center of the motor cylinder 17 in the direction of the tilt axis O of the motor swash plate 20. It is installed at a position eccentric by a fixed distance ε. Therefore, when the motor cylinder 17 rotates, each distribution valve 44 causes the eccentric wheel 4 within its valve hole 45.
7 is reciprocated between the outer position and the inner position using the eccentric amount ε as a stroke.

Each distribution valve 44 also has a function of connecting a supply oil passage 49 to the low-pressure oil passage 41 when it comes to a position inside the valve hole 45. The replenishing oil passage 49 is provided at the center of the support shaft 24 and is connected to the discharge port of the replenishing pump 50.

The replenishing pump 50 is driven from the crankshaft 1 to supply the oil in the oil reservoir 51 at the bottom of the crankcase 4 to the replenishing oil passage 49 at a relatively low pressure.

1, 3 and 4, the outer peripheral surface 20a of the motor swash plate 20 is formed into a spherical surface centered on the tilt axis O, and accommodates the motor swash plate 20 together with the thrust roller bearing 21. As described above, a spherical concave portion 52 is formed on the front surface of the swash plate holder 22. The back surface 22a of the swash plate holder 22 is formed in an arc surface centered on the tilt axis O of the motor swash plate 20, and the swash plate holder 22 is rotatably supported around the tilt axis O. A semi-cylindrical concave portion 53 is formed on the front surface of the swash plate anchor 23. The swash plate anchor 23 so as not to rotate around the output shaft 25 is locked to the crankcase 4 via the positioning pins 54.

At both ends of the swash plate holder 22, a pair of trunnion shafts 55 and 55 'arranged on the tilting axis O are integrally formed to protrude. The swash plate anchor 23 is rotatably supported. In other words, these trunnion shafts 55,
The tilt axis O is defined by 55 '.

An operating lever 57 is fixedly provided at the outer end of one trunnion shaft 55.

When the trunnion shaft 55 is rotated by the operation lever 57, the swash plate holder 22 integral with the trunnion shaft 55 is also rotated, so that the swash plate 20 can be freely tilted even during rotation of the motor swash plate 20.

In the above configuration, when the input member 5 of the hydraulic pump P is rotated from the primary reduction gear 2, the pump swash plate 1
0 alternately gives the pump plungers 9, 9... The suction and discharge strokes. Then, each pump plunger 9
Sucks hydraulic oil from the low-pressure oil passage 41 when performing the suction stroke, and feeds high-pressure hydraulic 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:
While being fed into the cylinder bore 18 which accommodates the motor plunger 19 during the expansion stroke via the distribution valve 44 located inward,
Hydraulic oil in the cylinder hole 18 accommodating the motor plunger 19 in the contraction stroke is discharged to the low-pressure oil passage 41 through the distribution valve 44 at an outer position.

During this time, the reaction torque received by the pump cylinder 7 from the pump swash plate 10 via the pump plunger 9 in the discharge stroke, and the reaction torque received by the motor cylinder 17 from the motor swash plate 20 via the motor plunger 19 in the expansion stroke. The pump cylinder 7 and the motor cylinder 17 are rotated by the sum of the torque and the rotation torque, and the rotation torque is output from the output shaft 25.
To the secondary reduction gear 3.

In this case, the output shaft 25 with respect to the input member 5
Is given by the following equation.

[0037]

(Equation 1)

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

Since the capacity of the hydraulic motor M is determined by the stroke of the motor plunger 19, the speed ratio is steplessly changed from 1 to a certain value by tilting the motor swash plate 20 from the upright position to a certain tilt position. Can be controlled.

During such operation of the hydraulic pump P and the hydraulic motor M, the pump swash plate 1 is from the pump plungers 9, 9,... And the motor swash plate 20 is the motor plungers 19, 1.
9 receives a thrust load in the opposite direction from the group, but the thrust load received by the pump swash plate 10 is transmitted through the thrust roller bearing 11, the input member 5, the thrust roller bearing 12, the support cylinder 13, and the nut 30 to the support shaft 2.
4 and the thrust load received by the motor swash plate 20 is a thrust roller bearing 21, a swash plate holder 22,
The swash plate anchor 23, the thrust roller bearing 32, the support cylinder 33, the sprocket 3a, and the nut 34 support the output shaft 25. Moreover, the support shaft 24 and the output shaft 25
Are integrally connected via the motor cylinder 17, the thrust load only causes a tensile stress in the motor cylinder 17 system, and the thrust load is completely applied to the crankcase 4 supporting the support shaft 24 and the output shaft 25. Does not work.

Furthermore , the swash plate holder 22 is supported so as to be tiltable.
The swash plate anchor 23 is simply attached to the crankcase 4.
Since it is locked so that it cannot rotate, the thrust
Can be kept stationary without applying any load.
Therefore, the tilting of the swash plate holder 22 is always smooth.
Can be done.

During the above operation, if 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 a position inside the valve hole 45, the distribution valve 45
Hydraulic fluid is supplied from the replenishing oil passage 49 to the low-pressure oil passage 41.

Referring again to FIG. 2, the operating lever 57 of the trunnion shaft 55 is used to tilt the motor swash plate 20.
Is connected to a transmission control device 60.

The shift control device 60 includes a pair of first cylinders 61 fixed to the swash plate anchor 23 and opposed to each other so as to slidably engage with the cylinder 61 and to hold the tip of the operating lever 57 in the rotation direction. And the second pistons 62 ₁ , 62 ₂
With the door, these pistons 62 _1, 62 ₂ are arranged so as to pivot the actuating lever 57 by its sliding.

The first and second pistons 62 ₁ , 62 ₂
Form first and second oil chambers 63 _1, 63 ₂ fractions of between the end wall of cylinder 61 facing each of these oil chambers 6
3 _1, 63 _2, spring 64 ₁ for pressing the corresponding piston 62 _1, 62 ₂ toward the actuating lever 57, 64 ₂ are housed.

The first and second oil chambers 63 _1, 63 ₂ are communicated with each other through a hydraulic conduit 66 that is interposed shift control valve 65 on the way, hydraulic oil is sealed in the these internal.

The shift control valve 65 includes a fixed valve housing 67.
And a rotary valve 69 rotatably fitted in a valve hole 68 of the valve housing 67. The rotary valve 69 is held at a hold position A by a speed change lever 70 fixedly provided at an outer end thereof. It is rotated to a deceleration position B and an acceleration position C on both sides.

The rotary valve 69 is provided with a communication port 72 provided with a check valve 71 interposed therebetween, and the valve box 67 is connected to the first oil chamber 63 ₁ and opens to one side of the valve hole 68. 1 bifurcated port 73 _1, and ₂ second fork port 73 opening is provided on the other side of the second oil chamber 63 ₂ in succession valve hole 68. The communication port 72 is located at the hold position A of the rotary valve 69.
Any of bifurcated port 73 _1, 73 without ₂ both communicate, permits the flow of oil in only one direction of deceleration position B in both bifurcated port 73 _1, 73 between ₂ and from the former 73 ₁ communicated to the latter 73 ₂ and it is adapted to permit the flow of oil in only one direction of the speed increasing position C in both bifurcated port 73 _1, 73 between ₂ and from the communicating latter 73 ₂ to the former 73 _2.

By the way, the motor plungers 19, 19 ...
, The thrust load exerted on the motor swash plate 20 by the motor plungers 19 during rotation of the motor cylinder 17 is different from one side of the motor swash plate 20 with respect to the tilt axis O. The strength alternates between the motor swash plate 20 and the motor swash plate 20. The oscillating tilting torque is applied to the operating lever 5.
It acts alternately as first and second pistons 62 _1, 62 ₂ in the pressing force via the 7.

When the shift lever 70 is shifted to the deceleration position B as shown in FIG.
3 ₁ but the second oil flow to the oil chamber 63 ₂ is permitted,
Since the flow in the opposite direction is blocked, the operation lever 57
Only from when the pressing force to the first piston 62 ₁ acts,
Oil flows from the first oil chamber 63 ₁ into the second oil chamber 63 _2, as a result the pistons 62 _1, 62 ₂ is moved to the first oil chamber 63 ₁ side, the actuating lever 57, the inclination of the motor swash plate 20 Direction.

On the contrary, if the shift lever 70 is shifted to the speed increasing position C, the check valve 71 causes the second oil chamber 63 _2.
From While oil flow first to the oil chamber 63 ₁ is permitted, the same since reverse flow is prevented, only when the pressing force acts from the operating lever 57 to the second piston 62 _2, second
Oil chamber oil flows from 63 ₂ to the first oil chamber 63 _1, as a result the pistons 62 _1, 62 ₂ is moved to the second oil 63 ₂ side, turning the operating lever 57 to the upright direction of the motor swash plate 20 Can be done.

When the shift lever 70 is returned to the hold position A, the communication between the _two oil chambers 63 ₁ and 632 is completely shut off.
Since the oil flow during that period is blocked, both pistons 6
2 _1, 62 ₂ becomes immovable, it is possible to hold the operating lever 57 at a position at that time, to fix the motor swash plate 20 in an upright position or inclined position.

One or more piston type clutch valves 80 are provided between the high and low pressure oil passages 40 and 41. The clutch valve 80 is slid into a radial valve hole 81 that penetrates from the high-pressure oil passage 40 to the low-pressure oil passage 41 and opens on the outer peripheral surface of the motor cylinder 17. Occupies (on position) both oil passages 4
0 and 41 are shut off, and when occupying the radially outward position (clutch off position), the two oil passages 40 and 41 communicate with each other.

The clutch valve 80 receives the oil pressure of the high-pressure oil passage 40 at its inner end so as to be biased toward the clutch-off position, and is slidably provided at its outer end on the outer periphery of the pump cylinder 7. The engaged clutch control ring 82 is engaged.

The clutch control ring 82 has a cylindrical inner peripheral surface 82b defining the clutch-on position of the clutch valve 80, and a tapered surface 82b connected to one end of the inner peripheral surface and defining the clutch-off position of the clutch valve 80. And holding the clutch valve 80 in the clutch-on position with a spring 83
Energized by The spring 83 is contracted between a clutch control ring 82 and a retainer 84 locked on the outer periphery of the pump cylinder 7.

The clutch control ring 82 includes a shift fork 8
5, connected to a clutch operation lever (not shown) via an intermediate lever 86 and a clutch wire 87. The shift fork 85 engages with the outer peripheral groove 88 of the clutch control ring 82,
An operating rod 89 fixed to the base penetrates through the crankcase 4 and is connected to the intermediate lever 86.

By pulling the clutch wire 87 and moving the clutch control ring 82 rightward in the figure against the force of the spring 83 via the shift fork 85, the taper surface of the clutch control ring 82 Since the clutch 82b faces the clutch valve 80, the clutch valve 80 is moved to the outer position, that is, the clutch off position by the pressure of the high-pressure oil passage 40. As a result, the high-pressure oil passage 40 and the low-pressure oil passage 41 are short-circuited through the valve hole 81, so that the pressure in the high-pressure oil passage 40 decreases, and the supply of the hydraulic oil to the hydraulic motor M becomes impossible. Can be deactivated.

When the clutch control ring 82 is moved to the left to operate the clutch valve 80 to the clutch-on position, the hydraulic oil is supplied between the hydraulic pump P and the hydraulic motor M through the high and low pressure oil passages 40 and 41 as described above. Thus, the hydraulic motor M can be returned to the operating state.

At an intermediate position of the clutch control ring 82 between the right and left movement positions, the clutch valve 80 operates the two oil passages 4.
The communication port between 0 and 41 is appropriately narrowed, and the hydraulic oil is circulated according to the opening degree, so that the hydraulic motor M can be brought into the half-clutch state.

In this embodiment, the support shaft 24 and the main shaft
25 constitutes the main shaft of the present invention.

[0061]

As described above, according to the first feature of the present invention.
For example, while connecting the cylinder to the main shaft so that it cannot move in the axial direction,
Surrounds the main shaft and tiltably supports the back of the swash plate holder
Insert the swash plate anchor into the thrust receiving member fixed to the spindle.
The bearings are rotatably supported via strike bearings.
This swash plate anchor is locked to the casing so that it cannot rotate.
And the thrust load generated between the cylinder and plunger
To the main shaft to reduce the load on the casing.
To reduce the thickness and weight of the casing.
be able to. Moreover, the swash plate anchor is
Static by casing without last load
The swash plate holder is always tilted smoothly.
I can make it.

According to a second aspect of the present invention, there is provided a syringe
The cylinder is formed integrally with the spindle, so the cylinder
Strengthens rigidity and enables more stable support of cylinder
You.

[Brief description of the drawings]

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

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

FIG. 3 is a sectional view taken along line 3-3 in FIG. 1;

FIG. 4 is an exploded perspective view of a main part of FIG. 1;

[Explanation of symbols]

ε eccentricity M variable displacement motor swash plate 22 swash plate as the motor plunger 20 swash plate as Motashirin da 1 9 plunger as crankcase 1 7 cylinder as a hydraulic motor O tilting shaft lines 4 casing as a hydraulic device holder 23 the swash plate anchor 24, the support shaft and the output shaft constitutes a 25 spindle 3 2 thrust Tobe bearings 33 support cylinder 5 4 positioning pins as the thrust receiving member

Claims (2)

(57) [Claims] 1. A casing (4) rotatably supported on a casing (4).
Syringes connected to the main shafts (24, 25) so that they can rotate integrally.
(17) and this cylinder (17) is parallel to its axis.
And a plurality of plungers (1
9) and the main shaft (24, 25).
Swash plate with its front surface in contact with the outer end of plunger (19)
(20) and disposed so as to surround the main shafts (24, 25).
Swash plate for rotatingly supporting the back of the swash plate (20)
And a swash plate holder (22).
Around the tilt axis (O) orthogonal to the axis of (24, 25)
Tilting to control the angle of the swash plate (20),
In the variable displacement hydraulic device, the cylinder (17) cannot be moved in the axial direction with respect to the main shaft (24, 25).
Swash plate surrounding the main shafts (24, 25)
Swash plate anchor for tiltably supporting the back of the holder (22)
(23) is attached to the thrust bearing fixed to the main shafts (24, 25).
Through the thrust bearing (32) to the support member (33)
The swash plate anchor (23)
Is fixed to the casing (4) in a non-rotatable manner.
Variable capacity hydraulic system. 2. A casing (4) rotatably supported on a casing (4).
Syringes connected to the main shafts (24, 25) so that they can rotate integrally.
(17) and this cylinder (17) is parallel to its axis.
And a plurality of plungers (1
9) and the main shaft (24, 25).
Swash plate with its front surface in contact with the outer end of plunger (19)
(20) and disposed so as to surround the main shafts (24, 25).
Swash plate for rotatingly supporting the back of the swash plate (20)
And a swash plate holder (22).
Around the tilt axis (O) orthogonal to the axis of (24, 25)
Tilting to control the angle of the swash plate (20),
In a variable displacement hydraulic device, a cylinder (17) is formed integrally with a main shaft (24, 25).
On the other hand, the swash plate holder (2) surrounds the spindles (24, 25).
2) Swash plate anchor ( 23) for tiltably supporting the back of (2 )
Receiving member fixed to the main shaft (24, 25)
(33) relative rotation via thrust bearing (32)
The swash plate anchor (23) is
Characterized in that it is non-rotatably locked to the thing (4).
Variable displacement hydraulic device.