JP2002005006A - Lubrication method of swash plate bearing in axial piston pump motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem that the conventional variable speed transmission which is constructed so that an charged hydraulic pressure is induced so sliding surface of bearing and movable swash plate through the oil gallery which needs many holes and plugs to close those holes, and this has increased in the assembling man-hour and the number of composing parts for axial piston pump motor. SOLUTION: By shaping the bearing holder 25 is shaped in one body with housing 1 and projecting the bearing fixing pin 25a from bearing holder 25 together, the pressured oil from charged oil gallery 6a in the oil gallery plate 6 is induced into penetration hole through 15 which penetrates abovementioned pin 25a through oil galley 11, 12, 13, 14, etc., which are formed in the housing and is supplied to the sliding surface of the bearing 24 with cradle swash plate 23 from above through hole 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating structure for an axial piston pump / motor in which a cradle swash plate bearing is supported by a bearing holder.

[0002]

2. Description of the Related Art Conventionally, one or both of a hydraulic pump and a hydraulic motor constituting a hydraulic type continuously variable transmission are constituted by an axial piston pump / motor in which a bearing of a cradle swash plate is supported by a bearing holder. May be. As described above, in the axial piston pump / motor constituting the hydraulic pump or the hydraulic motor, the oil film between the cradle swash plate and the bearing breaks with the elapse of the operation time, the sliding resistance increases, and the operation of the cradle swash plate is increased. Power may increase. Therefore, in order to suppress an increase in sliding resistance between the cradle swash plate and the bearing and to smoothly swing the cradle swash plate with a small operating force, the charge pressure is applied to the oil formed on the housing, the bearing holder, or the like. In some cases, the sliding surface is guided to a sliding surface between the bearing and the cradle swash plate through a road, and the sliding surface is lubricated to reduce sliding resistance. Further, the operating pressure of the plunger in the hydraulic pump or the hydraulic motor is guided to a sliding surface between the cradle swash plate and the bearing through a hole formed in the plunger shoe and a hole formed in the cradle swash plate to perform lubrication. Some did.

[0003]

However, as described above,
When the charge pressure is guided to the sliding surface between the bearing and the movable swash plate through the oil passage formed in the housing or bearing holder, the housing and the bearing holder are usually formed as separate members. In order to guide the charge pressure to the sliding surface between the bearing and the cradle swash plate, a large number of holes are formed in these members, and a large number of plugs for closing the hole ends are required. The man-hours for assembling the piston pump / motor and the number of components were increasing. Further, in the configuration in which the operating pressure of the plunger is guided to the sliding surface between the cradle swash plate and the bearing, the internal pressure of the plunger is leaked to the sliding surface. There was a problem that the noise was loud. Further, when the plunger shoe comes off, the lubricating efficiency is poor because the hydraulic oil flows backward.

[0004]

The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described. That is, in an axial piston pump / motor in which the bearing of the cradle swash plate is supported by a bearing holder, the bearing holder is formed integrally with the housing, and a bearing fixing pin is integrally projected from the bearing holder. Pressure oil from the charge oil passage of the oil passage plate is guided to a through hole penetrating the bearing fixing pin through an oil passage formed in the housing, and supplied to the cradle swash plate sliding surface of the bearing from the through hole. I do.

According to a second aspect of the present invention, in the axial piston pump / motor in which the bearing of the cradle swash plate is supported by a bearing holder and the bearing holder is formed integrally with the housing, the cradle swash plate on the bearing support surface of the bearing holder is provided. Forming a supply groove closed at both ends in the plate sliding direction, forming a supply hole communicating with the supply groove in the bearing,
Pressure oil from a charge oil passage of the oil passage plate is guided to the supply groove through an oil passage formed in the housing, and is supplied from the supply groove to a cradle swash plate sliding surface of the bearing through a supply hole.

According to a third aspect of the present invention, a plurality of the axial piston pump / motors are integrally provided side by side, and oil passages formed in housings of the respective axial piston pump / motors communicate with each other. A communication port with the charge oil passage was provided only in the oil passage in one axial piston pump / motor.

According to a fourth aspect of the present invention, in the axial piston pump / motor wherein the bearing of the cradle swash plate is supported by a bearing holder, a bearing fixing pin protruding from a center portion of the bearing holder in the sliding direction of the cradle swash plate. The bearing is swingably supported by, the bearing support surface shape of the bearing holder in the cradle swash plate sliding direction has a center at a position shifted outward from the center of the cradle swash plate sliding direction,
It was composed of two arc shapes extending from the center to one outside and the other outside, and the arc was formed to have substantially the same diameter as the outer diameter of the bearing.

According to a fifth aspect of the present invention, in the bearing support surface of the bearing holder, a concave portion in which a seal member is fitted is formed on both outer portions with respect to the center in the sliding direction of the cradle swash plate. A through-hole was formed in a portion corresponding to.

According to a sixth aspect of the present invention, the bearing is configured to be elastically deformable, and through holes are formed in both outer portions of the bearing with respect to the center in the sliding direction of the cradle swash plate. It was formed larger than the plate diameter.

[0010]

Next, an embodiment of the present invention will be described. FIG. 1 is a side sectional view showing a hydraulic stepless transmission constituted by using an axial piston pump / motor having a lubricating structure of a swash plate bearing according to the present invention, FIG. 2 is a plan sectional view thereof, and FIG. FIG. 4 is a side cross-sectional view showing a configuration of a bearing portion, and FIG. 4 is a side cross-sectional view showing a hydraulic continuously variable transmission configured using an axial piston pump / motor having a second embodiment of a swash plate bearing lubrication structure. 5 is a side sectional view showing the configuration of a bearing holder and a bearing portion of the axial piston pump / motor in FIG. 4, FIG. 6 is a front view thereof, and FIG. 7 is an axial piston pump having a third embodiment of a swash plate bearing lubrication structure. -Side sectional view showing a hydraulic stepless transmission constituted by using a motor, FIG. 8 is a plan sectional view, FIG. 9 is a rear view, and FIG. 10 shows a fourth embodiment of a swash plate bearing lubrication structure. Side sectional view showing the configuration of the bearing holder and the bearing portion in the axial piston pump / motor to be performed, FIG. 11 is a front sectional view of the same, FIG. 12 is a side sectional view showing a state in which the cradle swash plate in FIG. FIG. 13 is a side sectional view showing the configuration of a bearing holder and a bearing portion in an axial piston pump / motor having a fifth embodiment of a swash plate bearing lubrication structure, and FIG. 14 is a sixth embodiment of the swash plate bearing lubrication structure. FIG. 3 is a side cross-sectional view showing a configuration of a bearing holder and a bearing part in the axial piston pump / motor having the same.

First, the overall structure of a hydraulic continuously variable transmission 5 using an axial piston pump / motor having a swash plate bearing lubrication structure according to the present invention will be described. As shown in FIGS. 1 and 2, the hydraulic continuously variable transmission 5 is composed of a hydraulic pump 2 using an axial piston pump as a pump and a hydraulic motor 3 using an axial piston motor as a motor. The hydraulic pump 2 and the hydraulic motor 3 are vertically arranged side by side and are arranged on the same side surface of the oil passage plate 6, and the hydraulic pump 2 is configured as a variable displacement hydraulic pump.

The hydraulic pump 2 includes a housing 1, an oil passage plate 6, an input shaft 26 rotatably inserted into the housing 1,
It comprises a cylinder block 22 which rotates together with the input shaft 26, a plunger 21 slidably inserted into the cylinder block 22, a cradle swash plate 23 and the like. A bearing holder 25 is integrally formed with the housing 1, and the cradle swash plate 23 is swingably supported by the bearing holder 25 via a half bearing 24 as a bearing. The cradle swash plate 23 has a pin shaft 190
The cradle swash plate 23 is configured to be rotated by vertically operating the pin shaft 190 via the operation arm 189 with the trunnion shaft 188. Then, by rotating the cradle swash plate 23, the swash plate angle of the cradle swash plate 23 is controlled, and the capacity of the hydraulic pump 2 is continuously adjusted.

A charge pump 7 is provided on the outer surface of the oil passage plate 6, and the charge pump 7 is driven to rotate by an input shaft 26 which is a rotation shaft of the hydraulic pump 2. The end of the input shaft 26 on the cradle swash plate 23 side is rotatably supported by the housing 1 via a bearing 29.

On the other hand, the hydraulic motor 3 includes a housing 1, an oil passage plate 6, and an output shaft 3 rotatably inserted into the housing 1.
6. Cylinder block 3 that rotates with the output shaft 36
2, a plunger 31 slidably inserted into the cylinder block 32, a fixed swash plate 33 fixedly attached to the housing 1, and the like. Output shaft 36
The end on the side opposite to the oil passage plate 7 is rotatably supported by the housing 1.

Next, the swash plate bearing lubrication structure of the hydraulic pump 2 will be described. A first oil passage 11 is formed in an upper part of the housing 1 substantially in parallel with the input shaft 26 from an end surface of the oil passage plate 6 side to the opposite oil passage plate 6 side. 6
Second oil passage 1 communicating with the side end and extending in the direction of input shaft 26
2 are formed. The second oil passage 12 is formed substantially perpendicular to the first oil passage. That is, the first oil passage 11 is disposed substantially horizontally, and the second oil passage 12 is disposed substantially vertically. The oil passage plate 6 is formed with a charge oil passage 6a through which pressure oil from the charge pump 7 is fed under pressure. The charge oil passage 6a communicates with the first oil passage 11 of the housing 1 through a connection hole 6b. ing.

An annular groove 13 which is formed in an annular shape over the entire circumference is formed in a portion of the housing 1 in which the bearing 29 is supported and which comes into contact with the outer peripheral surface of the bearing 29. The groove 13 communicates with the second oil passage 12. Distribution oil passages 14 are formed in the housing 1 in a direction substantially horizontal and substantially perpendicular to the input shaft 26, and communicate with the annular groove 13. A plurality of the distribution oil passages 14 extend radially outward from the annular groove 13.

As shown in FIGS. 2 and 3, the bearing holder 2
5, a substantially central portion in the sliding direction of the cradle swash plate 23,
That is, a pin 25a for fixing the bearing protrudes from substantially the center of the upper and lower portions, and a hole 24a for fixing the position formed in the bearing 24 is inserted into the pin to position the bearing 24 with respect to the bearing holder 25. A through-hole 15 penetrates through the pin 25a.
14 and the sliding contact surface between the bearing 24 and the cradle swash plate 23 communicate with each other.

As described above, the oil passage plate 6 and the housing 1
The charge oil passage 6a and the connection hole 6 formed respectively.
b, the first oil passage 11, the second oil passage 12, the annular groove 13, the distribution oil passages 14, 14, and the through holes 15, 15 slide the charge oil passage 6a, the bearing 24 and the cradle swash plate 23. The contact surface is in communication with the contact surface, and the pressure oil from the charge pump 7 is forcibly supplied to the sliding contact surface between the bearing 24 and the cradle swash plate 23 through these oil passages, holes, and grooves. It is possible.

The annular groove 13 is formed on the inner surface of the housing 1, the first oil passage 11 is formed in a straight line, and one end thereof is opened at the end surface of the housing 1 on the oil passage plate 6 side. The second oil passage 12 is formed in a straight line shape, and one end of the second oil passage 12 is opened at the upper end surface of the housing 1.
The other end is in communication with the annular groove 13, and the plurality of distribution oil passages 14 are formed linearly with the annular groove 13 interposed therebetween. It is open on one side end surface, and the through holes 15 are formed in a straight line shape, and one end thereof is open on the inner side surface of the housing 1.

As a result, each of these oil passages 11, 12,.
The holes 14, the grooves 13, the grooves 13, and the like can be formed simultaneously by a die-casting mold when the housing 1 is molded. Therefore, the housing 1 necessary to form an oil passage or the like for guiding the pressure oil from the charge pump 7 to the sliding contact surface between the bearing 24 and the cradle swash plate 23 is provided.
The number of drill holes drilled after molding can be reduced, and the oil passage and the like can be formed at low cost. Incidentally, one end of the second oil passage 12 and one end of the distribution oil passage 14 which are opened to the outside even after the assembly of the axial piston pump / motor should be closed by screwing a plug 17 or the like. Can be. And, by adopting the oil passage configuration as described above, the plug 1 for closing these oil passages is formed.
7 can be reduced.

Next, a second embodiment of the swash plate bearing lubrication structure of the hydraulic pump 2 will be described with reference to FIGS. The hydraulic continuously variable transmission shown in FIGS. 4 to 6 is substantially similar to the hydraulic continuously variable transmission except that each oil passage described later formed in the housing 1 and one end of the input shaft 26 are directly rotatably supported by the housing 1. It is composed of a hydraulic pump 2 and a hydraulic motor 3 having the same configuration.

A first oil passage 51 is formed at an upper portion of the housing 1 substantially in parallel with the input shaft 26 from the end face of the oil passage plate 6 toward the oil passage plate 6 side. A second oil passage 52 communicating with the end of the oil passage plate 6 and extending toward the input shaft 26 is formed. The second oil passage 52 is formed substantially perpendicular to the first oil passage. That is, the first oil passage 51 is disposed substantially horizontally, and the second oil passage 52 is disposed substantially vertically. The oil passage plate 6 is formed with a charge oil passage 6a through which pressure oil from a charge pump of the hydraulic continuously variable transmission is pressure-fed. The charge oil passage 6a is connected to the second passage of the housing 1 by a connection hole 6b. It communicates with one oil passage 51. Further, a distribution oil passage 53 is formed in the housing 1 in a direction substantially horizontal and substantially orthogonal to the input shaft 26, and a middle part of the distribution oil passage 53 and a lower end of the second oil passage 52 communicate with each other. are doing.

As shown in FIGS. 5 and 6, the bearing holder 2
Bearing fixing pins 25a protruding from the upper and lower substantially central portions of
Is fitted in the position fixing hole 24a of the bearing 24,
4 is fixed, and a supply groove 25b having both ends closed is formed in the bearing support surface of the bearing holder 25 in the sliding direction (up and down direction) of the cradle swash plate 23. The supply groove 25 b is formed over substantially the entire vertical region of the bearing 24 support portion of the bearing holder 25. Further, a supply oil passage 54 communicating with the left and right supply grooves 25b extends from the distribution oil passage 53, respectively. Further, the bearing 24
Has a plurality of supply holes 24 at locations corresponding to the supply grooves 25b.
a, and the supply holes 24a are arranged, for example, above and below the position fixing holes 24a.

As described above, the oil passage plate 6 and the housing 1
The charge oil passage 6a and the connection hole 6 formed respectively.
b, the pressure oil from the charge pump 7 is pressure-fed to the supply groove 25b of the bearing holder 25 through the first oil passage 51, the second oil passage 52, the distribution oil passage 53, and the supply oil passage 54. Pressurized oil is supplied from the supply hole 24a to the bearing 24.
And the cradle swash plate 23 is forcibly supplied to the sliding contact surface.

The supply groove 25b is formed in a bearing holder 25 integrally formed with the housing 1. The first oil passage 51 is formed in a linear shape, and one end of the first oil passage 51 is provided in the oil passage of the housing 1. The second oil passage 52 is formed in a straight line, the one end thereof is opened in the upper end surface of the housing 1, and the distribution oil passage 53 is formed in a straight line. One end of the housing 1 is open on one side end surface, the supply oil passage 54 is formed linearly, and one end of the supply oil passage 54 is open on the inner side surface of the housing 1.

As a result, each of these oil passages 51, 52,
53 and 54 can be simultaneously formed by a die-casting mold when the housing 1 is formed. Further, the supply groove 25b formed in the bearing holder 25 can be formed simultaneously with the housing 1. it can. Therefore, the number of drill holes required after forming the housing 1 to form an oil passage or the like for guiding the pressure oil from the charge pump 7 to the sliding surface between the bearing 24 and the cradle swash plate 23 is required. And the supply groove 25b of the bearing holder 25 does not need to be formed by additional processing after the housing 1 is formed, so that the oil passages 51, 52, 53, 54, the supply groove 25a and the like can be further reduced in cost. Can be formed. Note that one end of the second oil passage 52 and one end of the distribution oil passage 53 which are opened to the outside even after the assembly of the axial piston pump / motor are closed by screwing the plug 17 or the like. Can be. And, by adopting the oil passage configuration as described above,
It is possible to reduce the number of plugs 17 for closing these oil passages.

Next, a third embodiment of the swash plate bearing lubrication structure of the hydraulic pump 2 will be described with reference to FIGS. FIGS. 7 to 9 show an example in which two hydraulic continuously variable transmissions each including a hydraulic pump 62 and a hydraulic motor 63 are arranged side by side and housed in the same housing 10 and oil passage plate 9. The hydraulic pump 62 and the hydraulic motor 63 of each hydraulic continuously variable transmission are substantially the same as the hydraulic pump 2 and the hydraulic motor 3, and each input shaft 26 is directly rotatably supported by the housing 10. Have been.

A first oil passage 66 is formed in the housing 10 above the one hydraulic pump 62 so as to be substantially parallel to the input shaft 26 from the end face of the oil passage plate 9 toward the oil passage plate 9 side.
The input shaft 2 communicates with the end of the first oil passage 66 on the side opposite to the oil passage plate 9.
Second oil passages 67 extending in six directions are formed. The second oil passage 67 is formed substantially perpendicular to the first oil passage. That is, the first oil passage 66 is disposed substantially horizontally, and the second oil passage 67 is disposed substantially vertically. The oil passage plate 9 is formed with a charge oil passage 9a through which pressure oil from a charge pump of the hydraulic continuously variable transmission is pressure-fed. A communication port 66a is opened at an end of the first oil passage 66 formed in the housing 10 on the oil passage plate 9 side. And the connection hole 9b
The communication with the communication port 66a of the first oil passage 66 allows the charge oil passage 9a to communicate with the first oil passage 66.

In each hydraulic pump 62, the input shaft 2
An annular groove 68 that is formed in an annular shape over the entire circumference is formed in a portion of the housing 1 in which the housing 6 is supported, in contact with the outer peripheral surface of the input shaft 26. From each annular groove 68, a first distribution oil passage 69a extends toward the left and right outer sides, and the annular distribution grooves 68 are connected by a second distribution passage 69b. 2 and 3, a through-hole 70 penetrates through the pin 25a of the bearing holder 25 in each hydraulic pump 62. The passage 69a and the second distribution passage 69b communicate with the sliding contact surface between the bearing 24 and the cradle swash plate 23 in each hydraulic pump 62.

As described above, the oil passage plate 9 and the housing 10
A charge oil passage 9a and a connection hole 9 formed respectively.
b, the communication port 66a, the first oil passage 66, the second oil passage 67, the annular grooves 68, 68, the first distribution oil passages 69a, 69a, the second distribution passage 69b, and the through holes 70, 70,. , The pressure oil from the charge pump is supplied to the bearing 2 of each hydraulic pump 62.
4 and the cradle swash plate 23 can be forcibly supplied to the sliding contact surface.

The annular grooves 68 are formed on the inner surface of the housing 1. The first oil passage 66 is formed in a linear shape, and one end of the first oil passage 66 is provided on the oil passage plate 9 side end surface of the housing 1. The second oil passage 67 is formed in a linear shape, one end of which is open to the upper end surface of the housing 1, and the other end thereof communicates with one annular groove 68. The one distribution oil passages 69a and 69a and the second distribution passage 69 are formed linearly with the annular grooves 68 therebetween, and one end of the first distribution oil passages 69a and 69a Opened at the other end face, the through holes 70
Are linearly formed, and one end thereof is open to the inner surface of the housing 1.

Thus, each of these oil passages 66, 67,
68 / 69a / 69a / 69b, holes 70/70 ...,
The grooves 68 can be formed simultaneously with the die casting mold when the housing 1 is molded. Therefore, after the housing 10 is formed, it is necessary to form an oil passage or the like for guiding the pressure oil from the charge pump to the sliding contact surface between the bearing 24 of each hydraulic pump 62 and the cradle swash plate 23. The number of drill holes can be reduced, and the oil passage and the like can be formed at low cost. One end of the second oil passage 67 and one end of the distribution oil passages 69a, 69a, which are open to the outside even after the assembly of the axial piston pump / motor, are connected to the plug 1
7 can be closed by screwing. And
With the oil passage configuration as described above, the number of plugs 17 for closing these oil passages can be reduced.

The communication port 66a for guiding the pressure oil from the charge pump to the first distribution oil passages 69a and 69a and the second distribution passage 69, the first oil passage 66, and the second oil passage 67 are provided on one side. Since it is formed only in the portion of the hydraulic pump 62,
The number of oil passages formed in the housing can be reduced as compared with the case where the two hydraulic pumps 62 are housed in separate housings, and the oil passages can be formed at lower cost. .

Next, a fourth embodiment of the swash plate bearing lubrication structure of the hydraulic pump 2 will be described with reference to FIGS. In the bearing holder 25 shown in FIGS. 10 to 12, the bearing 24 is pivotally fixed by a pin 25a protruding substantially at the center of the cradle swash plate 23 in the sliding direction (vertical direction). The bearing holder 25 includes a pin 25
a upper arc-shaped surface 25c located above the pin 25a and extending upward from the pin 25a, and a lower arc-shaped surface 25d located below the pin 25a and extending downward from the pin 25a. And two arc shapes.

The arc center P1 of the upper arc-shaped surface 25c is:
Cradle swash plate 23 Bearing holder 25 in sliding direction
It is shifted upward by the dimension d from the entire center line O, and the arc center P2 of the lower arc-shaped surface 25d is shifted downward by the dimension d from the center line O. The upper arc-shaped surface 25c
The arc diameters r1 and r2 of the lower arc-shaped surface 25d are equal to the arc diameter r0 of the contact surface of the bearing 24 with the bearing holder 25.
And are formed substantially identically.

By configuring the bearing holder 25 as described above, when the cradle swash plate 23 is at the neutral position,
A gap C1 and a gap C1 are provided between the upper arc-shaped surface 25c and the bearing 24 and between the lower arc-shaped surface 25d, respectively.
2 will occur. In this state, for example, when the cradle swash plate 23 is rotated downward, as shown in FIG. 12, a pressing force from the cradle swash plate 23 is applied to the bearing 24, and the lower part of the bearing 24 swings in the direction of the bearing holder 25. Then, the bearing 24 comes into close contact with the lower arc-shaped surface 25d.
On the other hand, the gap C1 remains formed between the upper arc-shaped surface 25c and the bearing 24. Conversely, cradle swash plate 2
3 is rotated upward, the upper part of the bearing 24 swings in the direction of the bearing holder 25 so that the bearing 24 comes into close contact with the upper arcuate surface 25c and the lower arcuate surface 25d 24 with the gap C2 still formed.

As described above, the bearing 24 pivotally supported by the pin 25a pivots in accordance with the rotation direction of the cradle swash plate 23, and the cradle is provided between the bearing holder 25 and the bearing 24. A gap C1 or a gap C2 is formed in a portion opposite to the direction of rotation of the swash plate 23.
Will form an oil film. Since this oil film is formed in either the gap C1 or the gap C2 according to the rotation direction of the bearing holder 25, it is possible to always lubricate the bearing 24 without forcibly supplying pressure oil, The life of the sliding member such as the bearing 24 can be extended. The bearing holder 25 has guide projections 2 on both sides of the bearing 24.
5e and 25e (shown in FIG. 11) are formed to prevent the bearing 24 from touching left and right when swinging.

As shown in FIG. 13, the bearing holder 25 shown in FIG. 10 to FIG.
5c and 25d, a concave portion 25f is formed.
A seal member 71 such as an O-ring may be fitted to f (FIG. 13 shows only the upper arc-shaped surface 25c). In this case, a through hole 72 is formed at a position corresponding to the recess 25 f in the bearing 24, and the seal member 71 protrudes from the bearing contact surface of the bearing holder 25.

With the above configuration, the bearing 24 on the opposite side to the rotation direction of the cradle swash plate 23 is
When pressed, the bearing 24 presses against the seal member 71, and the space in the recess 25 f surrounded by the seal member 71 is closed by the bearing 24. Thereafter, the space is narrowed by the swinging operation of the bearing 24 in the direction of the bearing holder 25, and the working oil filled in the space is passed through the through hole 72 to the sliding contact surface between the bearing 24 and the cradle swash plate 23. It is extruded and the sliding surface is lubricated.

As described above, by the swinging operation of the bearing 24 accompanying the turning operation of the cradle swash plate 23, the pressure oil is supplied to the sliding contact surface between the bearing 24 and the cradle swash plate 23, and the lubrication is forcibly performed. Therefore, the life of the sliding member such as the bearing 24 can be further extended with a simple configuration without requiring large-scale processing of the housing 1 or the like.

When the bearing holder 25 is constructed as shown in FIGS. 10 to 12, the bearing 24 can be formed as follows. That is, like the bearing 74 shown in FIG. 14, the diameter r3 of the bearing 74 is formed larger than the diameter r4 of the cradle swash plate 23. The bearing 74 is made of an elastic member, and the bearing 74 has a through hole 7 at a position corresponding to the upper and lower arc-shaped surfaces 25c and 25d.
4a and 74a are formed.

By making the diameter r3 of the bearing 74 larger than the diameter r4 of the cradle swash plate 23 (that is, the diameter of the bearing holder 25), the cradle swash plate 23 does not receive the pressing force from the cradle swash plate 23. Bearing 74 opposite to the rotation direction
, A gap C3 is formed between the bearing holder 25 and the bearing 74. Meanwhile, cradle swash plate 23
The bearing 74 on which is rotated is pressed by the cradle swash plate 23 and is elastically deformed to conform to the shapes of the cradle swash plate 23 and the bearing holder 25, so that no gap is generated.

When the cradle swash plate 23 is rotated in the opposite direction from this state, the bearing 74 on the side where the gap C3 has been formed is pressed by the cradle swash plate 23 and elastically deforms. The hydraulic oil that has been crushed and filled in the gap C3 is pushed out through the through hole 74a of the bearing 74 to the sliding contact surface between the bearing 74 and the cradle swash plate 23,
The sliding surface is lubricated.

As described above, due to the elastic deformation of the bearing 74 caused by the rotation operation of the cradle swash plate 23, the pressure oil is supplied to the sliding contact surface between the bearing 74 and the cradle swash plate 23, and the lubrication is forcibly performed. The life of the sliding member such as the bearing 74 can be further extended with a simple configuration without requiring large-scale processing of the housing 1 and the like.

[0045]

As described above, the present invention has the following advantages. That is, in an axial piston pump / motor in which a bearing of a cradle swash plate is supported by a bearing holder, the bearing holder is formed integrally with the housing, and a bearing fixing pin is integrally projected from the bearing holder. Guiding the pressure oil from the charge oil passage of the oil passage plate to a through hole passing through the bearing fixing pin through an oil passage formed in the housing;
Since oil is supplied from the through hole to the sliding surface of the cradle swash plate of the bearing, an oil passage for supplying pressure oil from the charge circuit to the sliding surface of the cradle swash plate is simultaneously formed by a die-cast mold when the housing is formed. It becomes possible. Accordingly, the number of drill holes formed in the housing as an oil passage for guiding the pressure oil from the charge pump 7 to the cradle swash plate sliding surface can be reduced, and the oil passage and the like can be formed at low cost. It becomes possible. Further, the number of plugs for closing the oil passage opening to the outside can be reduced.

Further, in the axial piston pump / motor wherein the bearing of the cradle swash plate is supported by a bearing holder and the bearing holder is formed integrally with the housing, the cradle on the bearing support surface of the bearing holder is provided. Forming a supply groove closed at both ends in the swash plate sliding direction, forming a supply hole communicating with the supply groove in the bearing,
The pressure oil from the charge oil passage of the oil passage plate is guided to the supply groove through an oil passage formed in the housing, and is supplied from the supply groove to the cradle swash plate sliding surface of the bearing through the supply hole. An oil passage for supplying pressure oil from the circuit to the cradle swash plate sliding surface can be formed at the same time by a die casting mold when the housing is formed. Accordingly, the number of drill holes formed in the housing as an oil passage for guiding the pressure oil from the charge pump 7 to the cradle swash plate sliding surface can be reduced, and the supply groove formed in the bearing holder can be reduced. Since it is not necessary to form the housing by additional processing after the housing is formed, the oil passage and the like can be formed at a lower cost. Further, the number of plugs for closing the oil passage opening to the outside can be reduced.

Further, a plurality of the axial piston pump / motors are integrally arranged side by side, and the oil passages formed in the housings of the axial piston pump / motors communicate with each other. Since the communication port with the charge oil passage is provided only in the oil passage in one axial piston pump / motor, an oil passage for supplying pressure oil from the charge circuit to the cradle swash plate sliding surface is used for molding the housing. In addition, it can be formed simultaneously by a die casting mold. Accordingly, the number of drill holes formed in the housing as an oil passage for guiding the pressure oil from the charge pump 7 to the cradle swash plate sliding surface can be reduced, and the oil passage and the like can be formed at low cost. It becomes possible. Further, the number of plugs for closing the oil passage opening to the outside can be reduced. In addition, since the communication port for guiding the pressure oil from the charge pump to the housing side is formed only in one axial piston pump / motor part, the two axial piston pump / motors are separately provided. The number of oil passages formed in the housing can be reduced as compared with the case where the oil passages are provided in the housing, and the oil passages can be formed at lower cost.

Further, in the axial piston pump / motor wherein the bearing of the cradle swash plate is supported by a bearing holder, the bearing for projecting from the center of the bearing holder in the sliding direction of the cradle swash plate is provided. The bearing is swingably supported by the pin, the bearing support surface shape of the bearing holder in the cradle swash plate sliding direction has a center at a position shifted outward from the center of the cradle swash plate sliding direction,
It is constituted by two arc shapes extending from the center part to one outside and the other outside, and the arc is formed to have substantially the same diameter as the outer diameter of the bearing, so that in the part in the direction opposite to the rotation direction of the cradle swash plate, A gap is formed between the bearing holder and the bearing, and an oil film is formed in the gap. Since this oil film is always formed in the gap generated regardless of the rotation direction of the bearing holder, it is possible to always lubricate the bearing without forcibly supplying the pressure oil, and the sliding member such as the bearing is used. Life can be extended.

Further, a recessed portion in which seal members are fitted on both outer portions of the bearing support surface of the bearing holder with respect to the center in the sliding direction of the cradle swash plate is formed, and the recessed portion of the bearing is formed. The through-hole is formed in the part corresponding to the part, the pressure oil is supplied to the sliding contact surface between the bearing and the cradle swash plate by the swinging operation of the bearing due to the rotation operation of the cradle swash plate, and the lubrication is forcibly performed Can do
The life of sliding members such as bearings can be further extended with a simple configuration without requiring large-scale processing of the housing.

Further, the bearing is configured to be elastically deformable, and through-holes are formed in both outer portions of the bearing with respect to the center in the sliding direction of the cradle swash plate. Because the swash plate is larger than the swash plate, pressure oil is supplied to the sliding contact surface between the bearing and the cradle swash plate due to the elastic deformation of the bearing due to the rotation operation of the cradle swash plate, and forced lubrication is performed. Thus, the life of sliding members such as bearings can be further extended with a simple configuration without requiring extensive processing of the housing.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a hydraulic continuously variable transmission configured using an axial piston pump / motor having a swash plate bearing lubrication structure of the present invention.

FIG. 2 is a plan sectional view of the same.

FIG. 3 is a side sectional view showing a configuration of a bearing holder and a bearing portion.

FIG. 4 is a side sectional view showing a hydraulic continuously variable transmission configured by using an axial piston pump / motor having a second embodiment of a swash plate bearing lubrication structure.

FIG. 5 is a side sectional view showing a configuration of a bearing holder and a bearing portion of the axial piston pump / motor in FIG.

FIG. 6 is a front view of the same.

FIG. 7 is a side sectional view showing a hydraulic continuously variable transmission configured by using an axial piston pump / motor having a third embodiment of a swash plate bearing lubrication structure.

FIG. 8 is a plan sectional view of the same.

FIG. 9 is a rear view of the same.

FIG. 10 is a side sectional view showing the configuration of a bearing holder and a bearing part in an axial piston pump / motor having a fourth embodiment of a swash plate bearing lubrication structure.

FIG. 11 is a front sectional view of the same.

FIG. 12 is a side sectional view showing a state where the cradle swash plate in FIG. 10 is rotated downward.

FIG. 13 is a side sectional view showing the configuration of a bearing holder and a bearing portion in an axial piston pump / motor having a fifth embodiment of a swash plate bearing lubrication structure.

FIG. 14 is a side sectional view showing a configuration of a bearing holder and a bearing part in an axial piston pump / motor having a sixth embodiment of a swash plate bearing lubrication structure.

[Explanation of symbols]

 Reference Signs List 1 housing 2 hydraulic pump 3 hydraulic motor 5 hydraulic continuously variable transmission 11 first oil passage 12 second oil passage 13 annular groove 14 distribution oil passage 15 through hole 23 cradle swash plate 24 bearing 25 bearing holder 25a pin 26 input shaft

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Kengo Sasahara 1-32 Chayacho, Kita-ku, Osaka-shi, Osaka F-term in Yanmar Diesel Co., Ltd. (reference) 3H070 AA01 BB04 BB06 CC01 CC21 CC27 CC32 CC35 DD33 DD35 DD91 DD94 3H071 AA03 BB01 CC21 CC27 CC32 CC34 DD46 DD82 3H084 AA08 AA16 BB24 BB27 CC33 CC57 CC58 CC60

Claims (6)

[Claims] In an axial piston pump / motor, a bearing of a cradle swash plate is supported by a bearing holder, and the bearing holder is integrally formed with a housing, and a bearing fixing pin is integrally projected from the bearing holder. Pressure oil from the charge oil passage is guided to a through hole passing through the bearing fixing pin through an oil passage formed in the housing, and supplied to the cradle swash plate sliding surface of the bearing from the through hole. A swash plate bearing lubrication structure for a hydraulic continuously variable transmission. 2. An axial piston pump / motor in which a bearing of a cradle swash plate is supported by a bearing holder, and the bearing holder is integrally formed with a housing, wherein both ends of the bearing support surface of the bearing holder in the sliding direction of the cradle swash plate. Form a closed supply groove, form a supply hole communicating with the supply groove in the bearing, and supply the pressure oil from the charge oil passage of the oil passage plate to the supply groove through an oil passage formed in the housing. A swash plate bearing lubricating structure for a hydraulic continuously variable transmission, wherein the swash plate bearing is guided and supplied from the supply groove to the cradle swash plate sliding surface of the bearing through a supply hole. 3. A plurality of said axial piston pumps.
The motors are integrally arranged side by side, and the oil passages formed in the housings of the axial piston pump / motors are communicated with each other, and only one of the oil passages in the axial piston pump / motor is connected to the charge oil passage. The swash plate bearing lubrication structure for a hydraulic continuously variable transmission according to claim 1 or 2, wherein a communication port is provided. 4. An axial piston pump / motor in which a bearing of a cradle swash plate is supported by a bearing holder, wherein the bearing is swingable by a bearing fixing pin projecting from a center portion of the bearing holder in a sliding direction of the cradle swash plate. The center of the bearing support surface of the bearing holder in the cradle swash plate sliding direction is shifted from the center of the cradle swash plate in the sliding direction to the outside, and extends from the center to one outside and the other outside. A swash plate bearing lubricating structure for a hydraulic continuously variable transmission, wherein the lubricating structure is constituted by two protruding circular arc shapes, and the circular arcs are formed to have substantially the same diameter as the outer diameter of the bearing. 5. A recess in which seal members are fitted on both outer portions of the bearing support surface of the bearing holder with respect to the center in the sliding direction of the cradle swash plate, and penetrates a portion corresponding to the recess in the bearing. The lubricating structure for a swash plate bearing of a hydraulic continuously variable transmission according to claim 4, wherein a hole is formed. 6. The bearing is configured to be elastically deformable, through holes are formed in both outer portions of the bearing with respect to the center in the sliding direction of the cradle swash plate, and the diameter of the bearing is larger than the diameter of the cradle swash plate. The lubricating structure for a swash plate bearing of a hydraulic continuously variable transmission according to claim 4, wherein the lubricating structure is formed.