JP2002054712A - Hydrostatic continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve assembling efficiency of a pump swash plate in a swash plate type hydraulic pump in a hydrostatic continuously variable transmission. SOLUTION: In this hydrostatic continuously variable transmission, a hydraulic closed circuit formed by a high pressure oil passage 53 for feeding operating fluid from the hydraulic pump P to the hydraulic motor M side and a low pressure oil passage 52 for feeding operating fluid from the hydraulic motor M side to the hydraulic pump P side is constructed between the hydraulic pump P and the hydraulic motor M. Engagement parts 12b, 162 where aligning parts 173, 174 of a jig 171 abut in assembling are formed on the pump swash plate 12 and the plate 10 of the hydraulic pump P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrostatic continuously variable transmission with improved assembling workability.

[0002]

2. Description of the Related Art Hydrostatic type continuously variable transmissions are known for motorcycles and automobiles. Such a hydrostatic continuously variable transmission is disclosed in, for example, Japanese Patent Publication No. 7-56340, Japanese Patent Application Laid-Open No. Hei 4-203553, and the like. FIG. 4 shows a schematic configuration thereof.

As shown in FIG. 4, this hydrostatic continuously variable transmission includes a constant displacement swash plate type hydraulic pump P connected to the crankshaft side of an engine, and a variable displacement type hydraulic pump P connected to the driving wheel side. And a swash plate type hydraulic motor M. Hydraulic pump P
The hydraulic motor M has an inner oil passage (low-pressure oil passage) 52 that is a low-pressure passage during normal load operation, but becomes a high-pressure passage during deceleration, that is, during reverse load operation, and a hydraulic motor M during normal load operation. Although it is a high pressure path, it is connected to form a hydraulic closed circuit via an outer oil path (high pressure oil path) 53 which becomes a low pressure path during reverse load operation. Supply pump 88 for sucking oil from oil sump 87
Are connected to the inner oil passage 52 via a first check valve 95 and are connected to the outer oil passage 53 via a second check valve 96.

[0004] A clutch valve 69 is provided between the inner oil passage 52 and the outer oil passage 53 and operates in accordance with a clutch operation by a driver. These clutch valves 69 are open to the outside with the clutch on position for disconnecting between the oil paths 52 and 53, the clutch off position for communicating between the oil paths 52 and 53, and the communication between the oil paths 52 and 53. It is possible to switch between three positions of communication and discharge.

[0005] A pressure regulating valve 97 is provided between the outer oil passage 53 and the inner oil passage 52. During normal load operation, that is, at the time of acceleration, when the oil passage of the outer oil passage 53 on the high pressure side becomes a certain value or more during the load operation, the outer oil passage 53
A part of the hydraulic oil of the above is guided to the inner oil passage 52,
This prevents the oil pressure inside the pump from becoming excessive.

[0006]

In the hydrostatic continuously variable transmission having the above-described structure, the constant displacement swash plate type hydraulic pump P is assembled at a predetermined inclination angle with respect to the pump swash plate (input shaft). It has a plate and a pump plunger (piston) which is slidably received in each of a number of cylinder holes formed in a cylinder block integral with the output shaft and whose outer end is engaged with the plate. The engagement between the plate and the outer end of the pump plunger is achieved by bringing the spherical portion at the outer end of each of the pump plungers into contact with a dimple hole formed in the surface of the plate.

On the other hand, in the cylinder block, a valve hole is formed in a radial direction inside each cylinder hole, and a distribution valve is accommodated therein so as to be movable in a radial direction, and these distribution valves reciprocate in a radial direction. The cylinder hole is switched between the inner oil passage and the outer oil passage by the movement. The dispensing valve is moved by the head of the distributing valve being driven by a ring-shaped eccentric cam provided on the pump swash plate. Therefore, the hydraulic pump P swings the plate by the rotation of the pump swash plate (input shaft) to reciprocate the pump plunger, and moves the distribution valve by the eccentric cam to switch between the inner oil passage and the outer oil passage. In order to perform the operation, accurate suction and discharge by the hydraulic pump cannot be realized unless these parts are correctly assembled. In particular, when assembling the pump plunger to the plate, the outer end of the pump plunger must be accurately positioned and brought into contact with the dimple hole on the plate to be assembled at a predetermined inclination angle.

Conventionally, the position of the plate and the pump plunger has been adjusted by touching the contact between the hemispherical tip of the pump plunger and the dimple hole of the plate by rotating the pump swash plate manually. Was.

However, since it relied on the tactile sensation of the worker,
The position of the dimple hole of the plate and the position of the pump plunger may not be determined. In particular, when an unskilled worker is assembling with a short tact of mass production, it takes a considerable amount of time to assemble the pump plunger, which may not fit in the dimple hole of the plate and may ride outside the dimple hole. , Which also increased costs.

[0010]

According to the present invention, there is provided a hydrostatic stepless motor comprising a closed hydraulic circuit between a fixed displacement swash plate hydraulic pump and a variable displacement swash plate hydraulic motor. In the transmission, the hydraulic pump includes a pump swash plate and a plate rotatably provided at a predetermined inclination angle with respect to the pump swash plate, and when the hydraulic pump is assembled to the pump swash plate and the plate. A hydrostatic continuously variable transmission, characterized in that an engagement portion for engaging with a positioning jig is provided on the transmission.

According to the hydrostatic continuously variable transmission having the above configuration,
By providing the plate and the pump swash plate with an engaging portion that engages with a positioning jig when the pump swash plate and the plate are assembled to a cylinder block integrated with the output shaft,
In assembling, the hydraulic pump can be accurately assembled by abutting the jig on the plate and the pump swash plate to accurately assemble the hydraulic pump.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a structure of a hydrostatic continuously variable transmission according to an embodiment applied to a power unit of a vehicle such as a motorcycle will be described with reference to FIG.

In FIG. 1, a swash plate type hydraulic pump P has an input cylinder shaft 5 provided with an output gear 2a of a primary reduction gear, and is rotatably supported on an inner peripheral wall of the input cylinder shaft 5 via a ball bearing 6. Pump cylinder 7, a large number of cylinder holes 8 provided in an annular arrangement around the rotation axis of the pump cylinder 7, and a plurality of pump plungers slidably fitted in the cylinder holes 8, respectively. 9 and
A plate 10 whose front surface is engaged and abutted on the outer end of each pump plunger 9;
The plate 1 is supported via an angular contact bearing 13 and a radial bearing 14 so as to maintain a state of being inclined at a fixed angle with respect to the axis of the pump cylinder 7 about a virtual trunnion shaft center O1 orthogonal to the axis of the pump.
And a pump swash plate 12 for supporting the zero. The pump swash plate 12 is formed integrally with the input cylinder shaft 5. When the input cylinder shaft 5 rotates, the pump swash plate 12 reciprocates the pump plunger 9 via the plate 10 and the bearings 13 and 14 to repeat the suction and discharge strokes.

On the surface of the plate 10, the same number of dimple holes 10a as the pump plunger 9 are formed.
The outer end of the pump plunger 9 is a hemispherical portion 9a, which engages with the dimple hole 10a.

The hydraulic motor M is integral with the pump cylinder 7 of the cylinder block B and is coaxial with the pump cylinder 7 and located at the right side of FIG. A cylinder hole 18 provided so as to surround the axis, a plurality of motor plungers 19 slidably fitted in the cylinder holes 18, and a front surface engaged with an outer end of each motor plunger 19.
It comprises a plate 20 to be abutted, a motor swash plate 22 for supporting the plate 20 via an angular contact bearing 27 and a radial bearing 28, and a motor swash plate anchor 23 for supporting the back surface of the motor swash plate 22. .

The opposing contact surfaces 22a, 23a of the motor swash plate 22 and the motor swash plate anchor 23, which are in contact with each other, are formed in a spherical shape centered on the intersection of the axis of the motor cylinder 17 and the trunnion shaft center O2. . In addition, the motor swash plate 22 is supported by a motor swash plate anchor 23 so as to enable relative rotation about the trunnion shaft center O2.

Motor cylinder 1 of motor swash plate anchor 23
A cylindrical cylinder holder 24 is continuously provided at the end on the seventh side, and a ball bearing 25 is interposed between the cylinder holder 24 and the outer periphery of the motor cylinder 17.

When the motor swash plate 22 is rotated around the trunnion shaft center O2 by the ball screw mechanism 79 connected to the motor 80, the plate 20 is in the upright position perpendicular to the axis of the motor cylinder 17. It operates between a maximum tilt position in which the motor cylinder 17 tilts at a certain angle.
A reciprocating motion is applied to the motor plunger 19 in accordance with the rotation of the motor, so that the expansion and contraction processes can be repeated.

Pump cylinder 7 and motor cylinder 17
Are integrally connected to each other to form a cylinder block B, and the cylinder block B and the output shaft 31 are integrated as described above.

One side of the output shaft 31 with respect to the cylinder block B passes through the plate 10 and the pump swash plate 12, and supports the end of the pump swash plate 12 via the angular contact ball bearing 33. . Also,
A ball bearing 35 is interposed between the pump swash plate 12 and the casing 4.

The other side of the output shaft 31 from the cylinder block B extends so as to penetrate the plate 20, the motor swash plate 22, and the motor swash plate anchor 23. Output shaft 3
1 (right end side in FIG. 1), the motor swash plate anchor 23 is provided via an angular contact bearing 41.
Is supported. The motor swash plate anchor 23 is integrated with the casing 4. The input gear 3a of the secondary reduction gear is mounted on the outer periphery of the output shaft 31 on the outer side in the axial direction of the output shaft 31.

The inside of the hollow output shaft 31 integral with the cylinder block B forms a supply oil passage 47. At one end (the left end in FIG. 1) of the output shaft 31, the supply oil passage 47 is connected to an oil reservoir 87 via an oil filter 89 and a supply pump 88. At the other end of the output shaft 31, the supply oil passage 47 is closed by a plug 48 or opened with a throttle.

An annular groove is formed on the outer peripheral surface of the output shaft 31 between the group of cylinder holes 8 of the pump cylinder 7 and the group of cylinder holes 18 of the motor cylinder 17.
An annular inner oil passage 52 is formed by the inner peripheral surface of the cylinder block B fitted integrally with the cylinder block B. Further, an annular groove is formed on the outer peripheral surface of the cylinder block B, and the ring body 56 integrally fitted on the outer peripheral surface of the cylinder block B is formed.
And an inner peripheral surface thereof, an annular outer oil passage 53 is formed.

The annular partition wall between the inner oil passage 52 and the outer oil passage 53 of the cylinder block B between the group of the cylinder holes 8 of the pump cylinder 7 and the group of the cylinder holes 18 of the motor cylinder 17, and the outer oil passage 53 The first valve holes 57 of the same number as the cylinder holes 8 are provided on the cylinder hole 8 group side so as to radially penetrate the outer peripheral wall, that is, the ring body 56, and the second valve holes 58 of the same number as the cylinder holes 18 are also provided. Are provided on the cylinder hole 18 group side, respectively. Each cylinder hole 8 and each first valve hole 57 are connected by a pump port 59, and each cylinder hole 18 and each second valve hole 58 are connected by a motor port 60.

A spool type first distribution valve 61 is slidably fitted in the first valve hole 57, and a spool type second distribution valve 62 is slidably fitted in the second valve hole 58, respectively.
The first distribution valve 61 is provided at the outer end of the first distribution valve 61.
1 and a second eccentric ring (eccentric cam) 64 surrounding the second distribution valve 62 at the outer end of the second distribution valve 62, and a slip ring (or ball). (Bearings) 65 and 66.

The outer end of the first distribution valve 61 is provided with a first eccentric ring 63.
Are connected to each other by a first expanding ring 67 concentric with the second eccentric ring 6.
4 are interconnected by a second expanding ring 68 which is concentric with the fourth expanding ring 68.

The first eccentric wheel 63 is provided integrally with the input cylinder shaft 5 and extends a predetermined distance from the center of the cylinder block B along the tilting center (virtual trunnion shaft center O1) of the pump swash plate 12. Eccentrically located. The second eccentric wheel 64 is connected to the cylinder holder 24 and is eccentric by a predetermined distance from the center of the cylinder block B along the tilt center (virtual trunnion shaft center O2) of the motor swash plate 20. Is located.

Here, the operation of the first distribution valves 61 will be described. When relative rotation occurs between the input cylinder shaft 5 and the pump cylinder 7, that is, the cylinder block B, each of the first distribution valves 61 becomes the first eccentric ring. The pump cylinder 7 is reciprocated between the radially inner position and the radially outer position of the pump cylinder 7 with a stroke of twice the eccentric distance in the first valve hole 57 by the stroke 63. Then, in the discharge area of the hydraulic pump P, the first distribution valve 61 moves on the inner side to connect the corresponding pump port 59 to the outer oil passage 53 and to the inner oil passage 52.
, Whereby hydraulic oil is pumped from the cylinder hole 8 to the outer oil passage 53 by the pump plunger 9 during the discharge stroke.

In the suction area of the hydraulic pump P, the first
The distributing valve 61 moves on the outer position side to connect the corresponding pump port 59 to the inner oil passage 52 and to the outer oil passage 53, thereby allowing the pump plunger 9 during the suction stroke to move the inner oil passage. Hydraulic oil is sucked from 52 into the cylinder hole 8.

The operation of the second distribution valve 62 will be described. When the motor cylinder 17, that is, the cylinder block B rotates, each of the second distribution valves 62 is moved by the second eccentric ring 64 in the second valve hole 58 to the second eccentric distance. The cylinder block B is reciprocated between the radially inner position and the radially outer position with the double distance as a stroke. In the expansion region of the hydraulic motor M, the second distribution valve 62 moves on the inward position side, connects the corresponding motor port 60 to the outer oil passage 53, and disconnects the motor port 60 from the inner oil passage 52, Thereby, high-pressure hydraulic oil is supplied from the outer oil passage 53 to the cylinder hole 18 of the motor plunger 19 during the expansion stroke.

In the contraction region of the hydraulic motor M, the second
The distribution valve 62 moves on the outer position side to connect the corresponding motor port 60 to the inner oil passage 52 and to cut off the connection between the motor port 60 and the outer oil passage 53, thereby allowing the motor plunger 19 to contract during the contraction stroke. The working oil is discharged from the cylinder hole 18 to the inner oil passage 52.

Thus, the cylinder block B is provided with the reaction torque that the pump cylinder 7 receives from the pump swash plate 12 via the pump plunger 9 during the discharge stroke, and the motor cylinder 1
7 is rotated by the sum of the reaction torque received from the motor swash plate 22 via the motor plunger 19 during the expansion stroke,
The rotation torque is transmitted from the output shaft 31 to the secondary reduction gear. In this case, the gear ratio of the output shaft 31 to the input cylinder shaft 5 is given by the following equation.

Gear ratio = 1 + (capacity of hydraulic motor M / capacity of hydraulic pump P)

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. In addition, since the capacity of the hydraulic motor M is determined by the stroke of the motor plunger 19, the speed ratio is steplessly controlled from 1 to a certain value by tilting the motor swash plate 22 from the upright position to a certain tilt position. can do.

Although not shown in FIG. 1, the clutch shown in FIG. 1 is provided between the first valve holes 57 and the second valve holes 58 at equal intervals of 120 degrees on the outer peripheral portion of the cylinder block B and adjacent to each other. A valve is provided. The operation of the clutch lever causes the inner oil passage 52 and the outer oil passage 5 to operate.
3 and a clutch-off position that moves from the clutch-on position to communicate between the inner oil passage 52 and the outer oil passage 53, and further moves from the clutch-off position. The communication between the inner oil passage 52 and the outer oil passage 53 and the communication / discharge position at which the inner oil passage 52 and the outer oil passage 53 are opened to the outside can be switched.

FIG. 2 shows one process of assembling the hydrostatic continuously variable transmission. 3A shows a cross section of the pump swash plate assembly, and FIG. 3B shows a front view of the plate 10.

As shown in FIG. 3A, the pump swash plate assembly 161 has an angular contact bearing 13 and an angular contact bearing 13 inside the input cylinder shaft 5 (a portion corresponding to the pump swash plate 12) constituting the case of the hydraulic pump P. The plate 10 is supported by the radial bearing 14 in a state of being inclined at a certain angle with respect to the center axis. On the surface of the plate 10, a predetermined number (seven in this case) of dimple holes 10a to be engaged with the spherical portion 9a at the end of the pump plunger 9 is formed. A notch 162 is formed on the back surface of the plate 10 as shown in FIG. A ball bearing 6 for rotatably supporting the pump cylinder 7 of the cylinder block B is also fitted into the input cylinder shaft 5. A notch 12b is formed in the flange portion 12a of the pump swash plate 12 of the input cylinder shaft 5 as an engaging portion for positioning a positioning jig described later. The flange portion 5a at the end of the input cylinder shaft 5 is
A bolt hole for attaching the output gear 2a of the primary reduction gear and a knock hole 5b for positioning the gear are provided.

As shown in FIG. 2, an assembly 164 of the output shaft 31 and the cylinder block B is provided on the jig base 163.
Is installed. Cylinder block / output shaft assembly 164
The pump plunger 9 is mounted on the cylinder hole 8 of the pump cylinder 7 of the cylinder block B integrated with the output shaft 31, and the first distribution valve 61 is further mounted on the first valve hole 57. The first distribution valve 61 is connected by a first expanded ring 67, and a slip ring 65 is provided outside the first distribution valve 67.

The jig base 163 has an upper surface serving as a reference surface 165, a concave portion provided in the reference surface 165, and a bottom surface serving as a receiving surface 16 for receiving the cylinder block B.
It is 6. A positioning hole 167 for guiding and positioning the output shaft 31 is formed in the receiving surface 166. Further, the pump swash plate assembly 1 is provided on the reference surface 165.
A pin hole 168 for positioning 61 is provided.

The output shaft 31 is inserted into the positioning hole 167 of the jig base 163 and the end surface of the cylinder block B on the side of the motor cylinder 17 is received by the receiving surface 166 so that the end surface of the input cylinder shaft 5 is positioned on the reference surface 165. Put on. Jig base 1
Positioning of the cylinder block / output shaft assembly 164 with respect to 63 is performed by using a mountain crushing part 32 which fills a groove of a spline provided on the output shaft 31 and crushes the mountain.

The pump swash plate assembly 161 is inserted from above the cylinder block / output shaft assembly 164, the inner end of the input cylinder shaft 5 is fitted to the slip ring 65, and the bearing 6 is fitted to the cylinder 7. , Pump swash plate assembly 16
One end surface is placed on the reference surface 165 of the jig base 163. The knock hole 5b of the flange portion 5a of the input cylinder shaft 5 is aligned with the pin hole 168 of the reference surface 165, and a positioning pin 169 is inserted therein, thereby positioning the pump swash plate assembly 161.

A positioning jig 171 is fitted to the end of the input cylinder shaft 5 of the pump swash plate assembly 161 on the side of the pump swash plate 12. The positioning jig 171 has a ring-shaped base portion 172, protrudes from the base portion 172, and is provided with a pump swash plate 1.
A reference alignment portion 173 fitted into the notch 12b provided in the second flange portion 12a; and a positioning shaft 175 of a predetermined length extending from the reference alignment portion 173 and having a spherical alignment portion 174 at the tip. Has become.

The plate 10 and the pump swash plate are fixed by fitting the positioning portion 174 at the tip of the positioning shaft 175 of the positioning jig 171 into the notch (groove) 162 on the back surface of the plate 10. Dimple hole 10
a is aligned with the pump plunger 9. That is, the position of the cylinder block / output shaft assembly 164 is determined with respect to the jig base 163, the position of the pump swash plate assembly 161 is determined with respect to the jig base 163, and the positioning of the pump swash plate assembly 161 is performed. The position of the jig 171 is determined.
Since the alignment with the notch 162 corresponding to 0a is performed, the position of the dimple hole 10a and the pump plunger 9 is uniquely determined, and the alignment is easily and accurately performed.

When the above positioning and assembling are completed, the positioning jig 171 is detached from the input cylinder shaft 5, and the bearing 33 for supporting the input cylinder shaft 5 with respect to the output shaft 31 is fitted therein. Thereafter, the pump swash plate assembly 161 is removed from the jig base 163 and the hydraulic motor M
The assembly and parts on the side are assembled.

The positioning jig 171 and the notch 1
62 is not limited to the above, and various shapes can be adopted.

[0046]

According to the hydrostatic continuously variable transmission according to the present invention, a hydrostatic continuously variable transmission having a closed hydraulic circuit between a constant displacement swash plate hydraulic pump and a variable displacement swash plate hydraulic motor is provided. In the transmission, since the plate and the pump swash plate of the hydraulic pump are provided with an engagement portion that engages with a positioning jig when the pump swash plate and the plate are assembled, the position of the dimple hole of the plate and the position of the pump plunger are reduced. Since it is determined uniquely, the hydraulic pump can be easily and accurately assembled even by a non-skilled person, so that the assembling tact time can be shortened and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hydrostatic continuously variable transmission according to the present invention.

FIG. 2 is a sectional view showing an assembling operation state of the hydrostatic continuously variable transmission.

FIG. 3A is a sectional view of a pump swash plate assembly,
(B) is a front view of the pump swash plate.

FIG. 4 is a schematic configuration diagram of a hydrostatic continuously variable transmission.

[Explanation of symbols]

4 casing, 5 input cylinder shaft, 8 cylinder hole, 7
Pump cylinder, 10 plate, 10a dimple hole 12 pump swash plate, 12a notch, 17 motor cylinder, 18 cylinder hole, 22 motor swash plate, 31
Output shaft, 47 supply oil passage, 52 inner oil passage, 53 outer oil passage, 56 ring body, 61 first distribution valve, 62 second distribution valve, 63 first eccentric ring, 64 second eccentric ring, 67
1st expanding ring, 68 2nd expanding ring, 88 refill pump, 95 first check valve, 96
Second check valve, 97 pressure regulating valve, 161 pump swash plate assembly,
162 notch, 163 jig base, 164 cylinder block / output shaft assembly, 171 positioning jig, 173 positioning unit, 174 positioning shaft,
B cylinder block, P swash plate type hydraulic pump, M swash plate type hydraulic motor,

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuhiro Takeuchi 1-4-1 Chuo, Wako-shi, Saitama Prefecture Inside Honda R & D Co., Ltd. (72) Yasuji Fujimoto 1-4-1 Chuo, Wako-shi, Saitama Prefecture F-term in Honda R & D Co., Ltd. (Reference) 3H070 AA01 BB04 BB07 CC32 DD31 DD91 3H084 AA08 AA16 BB24 CC32 CC58

Claims (1)

[Claims] 1. A hydrostatic continuously variable transmission in which a closed hydraulic circuit is formed between a constant displacement swash plate hydraulic pump and a variable displacement swash plate hydraulic motor, wherein the hydraulic pump comprises a pump swash plate, The pump has a plate rotatably provided at a predetermined inclination angle with respect to the pump swash plate, and the pump swash plate and the plate have an engagement portion that engages with a positioning jig when assembling the hydraulic pump. A hydrostatic continuously variable transmission characterized by the following: