JP2004108552A - Hydraulic continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that miss assembly of one side surface and another side surface of a thrust plate can not be discriminated and efficiency drops with the lapse of time in a conventional HST. <P>SOLUTION: This transmission 10 is constructed in such a manner that a plunger shoe 11f provided on an end part of a plunger 11e slide-contacts one side surface of a thrust plate 33 assembled on a movable swash plate 11c. A groove part 33a capable of communicating an inside of the plunger 11e and an outside of the plunger 11e is formed at a position corresponding to slide-contact of the plunger shoe 11f on another side surface of the thrust plate 33. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydraulic continuously variable transmission including a hydraulic pump and a hydraulic motor, and more particularly, to a configuration of a thrust plate assembled to a swash plate of a hydraulic pump or the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a hydraulic continuously variable transmission (hereinafter, HST) including a hydraulic pump and a hydraulic motor, a thin plate-shaped thrust plate is assembled to a swash plate of a hydraulic pump or the like, and a plunger is provided on one side of the thrust plate. The plunger shoe was in sliding contact.
One side surface of the thrust plate is configured to be smooth by performing a lapping process or the like to reduce the sliding resistance of the plunger shoe.
The plunger shoe is provided with an oil supply hole communicating between the inside and outside of the plunger, and a hydraulic oil filled in the inside of the plunger forms a lubricating oil film between the thrust plate and the plunger shoe. Was configured to decrease. Since the periphery of the oil supply hole of the plunger shoe is tightly sealed to the thrust plate, the hydraulic oil inside the plunger does not leak out more than necessary.
An example of a hydraulic continuously variable transmission configured so that the plunger shoe is in sliding contact with the thrust plate incorporated in the swash plate is disclosed, for example, in Japanese Patent Application Laid-Open No. H11-163,098.
[0003]
[Patent Document 1]
JP 2001-165276 A
[Problems to be solved by the invention]
Since the above-mentioned thrust plate is formed in a disc shape and it is difficult to distinguish one side surface from the other side surface, the one side surface and the other side surface may be mistaken for the swash plate.
Normally, the other side of the thrust plate has a large surface roughness because it is not wrapped unlike the one side, so if one side and the other side are reversely assembled, the other side and the plunger Since the sliding resistance between the shoe and the shoe is large and the sliding torque loss of the plunger is large, a problem occurs that the mechanical efficiency is greatly reduced.
However, a thrust plate whose surface roughness on the other side is small to some extent may sometimes be created. When such a thrust plate having a small surface roughness on the other side is erroneously operated and the other side comes into sliding contact with the plunger shoe, at the beginning of the operation of the hydraulic continuously variable transmission, the gap between the other side and the plunger shoe is started. Since the sliding resistance is not so large and the sliding torque loss of the plunger is small, it can be operated without any particular problem with a small decrease in mechanical efficiency, and the performance standard in the shipping inspection may be cleared.
In the case where the thrust plate is misconfigured in this way, although the initial operation is normal, the sliding resistance between the other side of the thrust plate and the plunger shoe increases due to the short-time operation, and the shoe surface of the piston shoe is increased. Will wear, and a problem due to a decrease in efficiency will occur.
Therefore, in the present invention, even when one side and the other side of the thrust plate are erroneously configured, it is possible to reliably determine the erroneously configured product and prevent a malfunction from occurring over time. A continuously variable transmission is provided.
[0005]
[Means for Solving the Problems]
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 the hydraulic continuously variable transmission having a configuration in which the plunger shoe provided at the end of the plunger slides on one side of the thrust plate assembled to the swash plate, the plunger shoe slides on the other side of the thrust plate. At a position corresponding to the contact, a groove was formed to allow communication between the inside of the plunger and the outside of the plunger.
[0006]
In claim 2, the groove is a groove formed substantially along the circumference of the thrust plate.
[0007]
Further, in claim 3, the groove is a groove formed substantially along the radial direction of the thrust plate.
[0008]
In the fourth aspect, the groove is a concave hole having a diameter larger than a seal width of a plunger shoe for sealing between the inside of the plunger and the outside of the plunger.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described.
1 is a side sectional view showing a hydraulic continuously variable transmission according to the present invention, FIG. 2 is a front view showing a thrust plate fitted to a movable swash plate, FIG. 3 is a side sectional view of the same, and FIG. FIG. 5 is a view showing a second embodiment of the other side of the thrust plate, FIG. 6 is a view showing a third embodiment of the other side of the thrust plate, and FIG. It is a figure showing four examples.
[0010]
The configuration of the hydraulic continuously variable transmission according to the present invention will be described. In FIG. 1, a hydraulic continuously variable transmission (hereinafter, referred to as HST) 10 includes a hydraulic pump 11 and a hydraulic motor 12. The hydraulic pump 11 and the hydraulic motor 12 are included in a housing 31 and, for example, an oil passage plate. 32 are arranged on the same surface.
The hydraulic pump 11 includes a drive shaft 11a, a plunger block 11b into which the drive shaft 11a is inserted and rotates together with the drive shaft 11a, a plunger 11e slidably inserted into the plunger block 11b, a movable swash plate 11c, and a movable swash plate. It is composed of a thrust plate 33 fitted on the swash plate 11c and a plunger 11e slidingly contacting the thrust plate 33 via a plunger shoe 11f, and is configured as a variable displacement hydraulic pump.
The movable swash plate 11c regulates the sliding amount of the plunger 11e, and is configured to be able to adjust the discharge amount of the hydraulic oil of the hydraulic pump 11.
[0011]
Similarly to the hydraulic pump 11, the hydraulic motor 12 is inserted into an oil passage plate 32, and one end of the output shaft 12a is rotatably supported by the housing 31, and the output shaft 12a is inserted and fitted together with the drive shaft 12a. It comprises a rotating plunger block 12b, a plunger 12e slidably inserted in the plunger block 12b, a swash plate 12c, and a plunger 12e abutting on a thrust plate 34 via a plunger shoe 12f.
The cylinder block 12b is configured to rotate together with the output shaft 12a, and a plunger 12e is slidably inserted into the cylinder block 12b.
[0012]
In the HST 10 thus configured, hydraulic oil flows in and out between the main circuit formed in the oil passage plate 32 and the hydraulic pump 11 and flows in and out between the main circuit and the hydraulic motor 12. Things.
With the above configuration, when the driving force is input to the driving shaft 11a and the hydraulic pump 21 is driven, the hydraulic oil discharged from the hydraulic pump 11 is supplied to the hydraulic motor 12 through the oil passage plate 32, and The hydraulic motor 12 is driven by the hydraulic oil, and the driving force is output from the output shaft 12a.
[0013]
Next, the thrust plate 33 will be described.
As shown in FIGS. 2 and 3, the thrust plate 33 formed in a thin disk shape is assembled to the movable swash plate 11 c of the hydraulic pump 11, and one side surface of the thrust plate 33 (the plunger shoe 11 f and the The plunger shoe 11f of the plunger 11e is in sliding contact with the opposing surface).
One side surface of the thrust plate 33 is configured to be smooth by performing a lapping process or the like to reduce sliding resistance with the plunger shoe 11f. The other side is not particularly subjected to a smoothing process, and is configured to have a coarser surface roughness than one side.
[0014]
The plunger shoe 11f is provided with an oil supply hole 11g that allows communication between the inside 11k of the plunger 11e and the outside (the space inside the housing 31), and the working oil filled in the plunger inside 11k is supplied through the oil supply hole 11g. It is configured to leak between the thrust plate 33 and the plunger shoe 11f to form a lubricating oil film.
By forming a lubricating oil film between the thrust plate 33 and the plunger shoe 11f, the sliding resistance of the plunger shoe 11f with respect to the thrust plate 33 is further reduced.
In addition, since the periphery of the oil supply hole 11g of the plunger shoe 11f is formed in the seal portion 11h that seals tightly with the thrust plate 33, the hydraulic oil inside the plunger 11k does not leak out more than necessary.
[0015]
As shown in FIG. 4, a circumferential groove portion 33 a is formed on the other side surface of the thrust plate 33. The groove 33a is provided at a position corresponding to the sliding contact position of the plunger shoe 11f (when the thrust plate 33 is fitted on the movable swash plate 11c such that the other side faces the plunger shoe 11f, the plunger shoe is formed on the other side. 11f is in a position where the sliding contact is made).
[0016]
Here, since the thrust plate 33 is formed in a disk shape and it is difficult to distinguish one side surface from the other side surface, the one side surface and the other side surface are mistaken for the movable swash plate 11c. Sometimes.
When the thrust plate 33 is assembled on the movable swash plate 11c with one side face and the other side face reversed, the plunger shoe 11f slidably contacts the other side face, but the groove 33a is located at the sliding contact position of the plunger shoe 11f. Thus, the oil supply hole 11g of the plunger shoe 11f connected to the plunger interior 11k communicates with the outside of the plunger 11e through the groove 33a.
As a result, the hydraulic oil filled in the plunger interior 11k leaks out of the plunger 11e through the groove 33a, and the volume efficiency of the HST 10 is greatly reduced.
[0017]
As described above, when the thrust plate 33 is assembled on the movable swash plate 11c with one side surface and the other side surface reversed, hydraulic oil leaks out of the plunger 11e through the annular groove portion 33a formed in the thrust plate 33, and the HST 10 By configuring so that the volumetric efficiency is reduced, even if the designed thrust plate 33 is a thrust plate 33 having a small surface roughness on the other side to some extent, it meets performance standards such as volumetric efficiency in shipping inspection and the like. Therefore, it is possible to prevent a product in which the thrust plate 33 is misconfigured from being shipped. In this case, since the jet oil (abnormal sound) is generated by the hydraulic oil leaking through the groove 33a, it is also possible to detect an abnormality of the product.
Accordingly, there arises a problem that the sliding resistance between the other side surface of the thrust plate 33 and the plunger shoe 11f increases with time of the shipped product in the market, and the volume efficiency of the HST 10 is greatly reduced. Can be prevented.
Further, since the groove 33a is a single annular groove, the thrust plate 33 can be easily and inexpensively processed with a lathe or the like.
[0018]
Further, the groove formed on the other side surface of the thrust plate 33 can be formed as a spiral groove, as in a groove 33b shown in FIG.
In this way, by forming a groove formed along the substantially circumferential direction of the thrust plate 33 on the other side, such as an annular shape or a spiral shape, one side and the other side of the thrust plate 33 are formed. It is possible to find out the wrong mechanism of the system.
[0019]
Further, as a groove formed on the other side surface of the thrust plate 33, a groove 33c formed along the radial direction of the thrust plate 33, such as a groove 33b shown in FIG. Similarly to the case of the groove portions 33a and 33b formed by the above, it is possible to surely find an erroneous mechanism between one side surface and the other side surface of the thrust plate 33.
It should be noted that the groove 33c may be formed by only one or a plurality of grooves.
[0020]
Also, as shown in FIG. 7, even if a recessed hole 33d having a diameter larger than the seal width of the outer peripheral portion of the oil supply hole 11g of the plunger shoe 11f is formed on the other side of the thrust plate 33, one side of the thrust plate 33 is similarly formed. It is possible to find out the wrong mechanism of the other aspect.
The thrust plate 33d can be easily and inexpensively machined on the thrust plate 33 with a drilling machine or the like, and only one or a plurality of the holes can be formed.
[0021]
【The invention's effect】
First, in a hydraulic continuously variable transmission in which a plunger shoe provided at an end of a plunger slides on one side of a thrust plate assembled to a swash plate, a plunger on the other side of the thrust plate is provided. Since a groove is formed at the position corresponding to the shoe sliding contact, the groove allows communication between the inside of the plunger and the outside of the plunger.
If one side and the other side of the thrust plate are assembled on the movable swash plate with the other side reversed, the hydraulic oil leaks to the outside of the plunger due to the groove formed in the thrust plate, and the volumetric efficiency of the HST decreases. Can be prevented from being shipped. In this case, since the jet oil (abnormal sound) is generated by the hydraulic oil leaking through the groove, it is also possible to detect an abnormality of the product by this.
Therefore, there is a problem in that the shipped product over time in the market, the sliding resistance between the other side of the thrust plate and the plunger shoe increases, and the mechanical efficiency of the HST is greatly reduced. Can be prevented.
[0022]
As described in claim 2, since the groove is a groove formed along a substantially circumferential direction of the thrust plate,
When one side and the other side of the thrust plate are assembled to the movable swash plate with the other side reversed, the hydraulic oil flows outside the plunger due to the groove formed along the substantially circumferential direction, such as an annular shape or a spiral shape formed on the thrust plate. And the volume efficiency of the HST is reduced, so that it is possible to prevent the product in which the thrust plate is misconfigured from being shipped. In this case, since the jet oil (abnormal sound) is generated by the hydraulic oil leaking through the groove, it is also possible to detect an abnormality of the product by this.
Therefore, there is a problem in that the shipped product over time in the market, the sliding resistance between the other side of the thrust plate and the plunger shoe increases, and the mechanical efficiency of the HST is greatly reduced. Can be prevented.
Further, since the groove is a groove having a shape substantially along the circumferential direction, the thrust plate can be easily and inexpensively processed on a lathe or the like.
[0023]
As described in claim 3, since the groove is a groove formed along a substantially radial direction of the thrust plate,
When one side of the thrust plate and the other side are reversed and assembled to the movable swash plate, the hydraulic oil leaks to the outside of the plunger due to the grooves formed in the thrust plate along the substantially radial direction, and the volumetric efficiency of the HST is reduced. Is reduced, so that it is possible to prevent the product in which the thrust plate is misconfigured from being shipped. In this case, since the jet oil (abnormal sound) is generated by the hydraulic oil leaking through the groove, it is also possible to detect an abnormality of the product.
Therefore, there is a problem in that the shipped product over time in the market, the sliding resistance between the other side of the thrust plate and the plunger shoe increases, and the mechanical efficiency of the HST is greatly reduced. Can be prevented.
Further, since the groove is formed substantially along the radial direction, the thrust plate can be easily and inexpensively processed on a lathe or the like.
[0024]
As described in claim 4, the groove is a concave hole having a diameter larger than a seal width of a plunger shoe for sealing between the inside of the plunger and the outside of the plunger.
When one side and the other side of the thrust plate are assembled on the movable swash plate with the other side reversed, the hydraulic oil leaks to the outside of the plunger due to the recessed holes formed in the thrust plate, and the volumetric efficiency of the HST decreases, It is possible to prevent a product in which the thrust plate is misconfigured from being shipped. In this case, since the jet oil (abnormal sound) is generated by the hydraulic oil leaking through the recessed hole, it is also possible to detect an abnormality of the product.
Therefore, there is a problem in that the shipped product over time in the market, the sliding resistance between the other side of the thrust plate and the plunger shoe increases, and the mechanical efficiency of the HST is greatly reduced. Can be prevented.
Further, since the groove formed in the thrust plate is a concave hole, the thrust plate can be easily and inexpensively processed with a drilling machine or the like.
[Brief description of the drawings]
FIG. 1 is a side sectional view showing a hydraulic continuously variable transmission according to the present invention.
FIG. 2 is a front view showing a thrust plate fitted to a movable swash plate.
FIG. 3 is a side sectional view of the same.
FIG. 4 is a view showing another side surface of the thrust plate.
FIG. 5 is a view showing a second embodiment of the other side surface of the thrust plate.
FIG. 6 is a diagram showing a third embodiment of the other side surface of the thrust plate.
FIG. 7 is a view showing a fourth embodiment of the other side surface of the thrust plate.
[Explanation of symbols]
10 HST transmission 11 Hydraulic pump 12 Hydraulic motor 11e Plunger 11f Plunger shoe 11g Oil supply hole 33 Thrust plate 33a Groove

Claims (4)

In a hydraulic continuously variable transmission having a configuration in which a plunger shoe provided at the end of a plunger slides on one side of a thrust plate assembled to a swash plate,
A hydraulic continuously variable transmission, wherein a groove is formed at a position corresponding to the sliding contact of the plunger shoe on the other side surface of the thrust plate so that the inside of the plunger can communicate with the outside of the plunger. The hydraulic continuously variable transmission according to claim 1, wherein the groove is a groove formed along a substantially circumferential direction of a thrust plate. The hydraulic continuously variable transmission according to claim 1, wherein the groove is a groove formed along a substantially radial direction of a thrust plate. The hydraulic continuously variable transmission according to claim 1, wherein the groove is a recessed hole having a diameter larger than a seal width of a plunger shoe for sealing between the inside of the plunger and the outside of the plunger.

Images