JP3869340B2 - Hydraulic continuously variable transmission - Google Patents

Description

[0001]
BACKGROUND 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 such as a hydraulic pump.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a hydraulic continuously variable transmission (hereinafter referred to as HST) composed of a hydraulic pump and a hydraulic motor, a thin plate-like thrust plate is assembled to a swash plate such as a hydraulic pump, and a plunger is attached to one side surface of the thrust plate. The plunger shoe was in sliding contact.
One side surface of the thrust plate is configured to be smooth by, for example, lapping treatment to reduce the sliding resistance of the plunger shoe.
In addition, the plunger shoe has an oil supply hole that communicates the inside and outside of the plunger, and a hydraulic oil filled inside the plunger forms a lubricating oil film between the thrust plate and the plunger shoe for further sliding resistance. Was configured to decrease. Since the periphery of the oil supply hole of the plunger shoe is tightly sealed with the thrust plate, the hydraulic oil inside the plunger does not leak out more than necessary.
As described above, as a hydraulic continuously variable transmission configured such that the plunger shoe is slidably contacted with a thrust plate incorporated in a swash plate, for example, there is one shown in Patent Document 1 below.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2001-165276
[Problems to be solved by the invention]
The thrust plate described above is formed in a disc shape, and it is difficult to distinguish one side from the other side, so it may be mistaken for one side and the other side to work on the swash plate. .
Usually, the other side surface of the thrust plate is not lapped unlike the one side surface, so the surface roughness is large. Therefore, if the one side surface and the other side surface are structured in reverse, the other side surface and the plunger Since the sliding resistance with the shoe is large and the sliding torque loss of the plunger is large, there is a problem that the mechanical efficiency is greatly reduced.
However, sometimes a thrust plate having a small surface roughness on the other side surface is sometimes produced. When such a thrust plate with a small surface roughness on the other side surface is malfunctioned and the other side surface is in sliding contact with the plunger shoe, the hydraulic continuously variable transmission is initially placed between the other side surface and the plunger shoe. Since the sliding resistance of the plunger is not so large and the sliding torque loss of the plunger is small, it can be operated without any problem with little decrease in mechanical efficiency, and the performance standard in the shipping inspection may be cleared.
In the case where the thrust plate is misoperated in this way, although the initial operation is normal, the sliding resistance between the other side surface of the thrust plate and the plunger shoe increases due to the short-time operation, and the shoe surface of the piston shoe Will wear out, causing problems due to reduced efficiency.
Therefore, in the present invention, even if one side surface and the other side surface of the thrust plate are misstructured, it is possible to reliably determine the misstructured product and prevent the occurrence of problems over time. A continuously variable transmission is provided.
[0005]
[Means for Solving the Problems]
The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.
That is, in the first aspect, on one side of the thrust plate to be assembled to the swash plate, the hydraulic CVT configurations plunger shoe provided at the plunger end is in sliding contact, the plunger shoe at the other side of the thrust plate By communicating between the inside of the plunger and the outside of the plunger at a position corresponding to the sliding contact, a groove for discriminating the erroneously structured product when the one side surface and the other side surface of the thrust plate are erroneously formed is formed.
[0006]
According to a second aspect of the present invention, the groove is a groove formed along a substantially circumference of the thrust plate.
[0007]
According to a third aspect of the present invention, the groove is a groove formed along a substantially radial direction of the thrust plate.
[0008]
According to a fourth aspect of the present invention, the groove is a hollow having a diameter larger than the seal width of the plunger shoe that seals between the inside of the plunger and the outside of the plunger.
[0009]
DETAILED DESCRIPTION OF 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, and FIG. FIG. 5 is a diagram showing a second embodiment of the other side of the thrust plate, FIG. 6 is a diagram showing a third embodiment of the other side of the thrust plate, and FIG. It is a figure which shows the 4th Example.
[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 enclosed in a housing 31 and, for example, an oil path plate. 32 are arranged on the same surface. The hydraulic pump 11 includes a drive shaft 11a, a plunger block 11b in which the drive shaft 11a is inserted and rotated together with the drive shaft 11a, a plunger 11e slidably inserted in the plunger block 11b, a movable swash plate 11c, and the movable The thrust plate 33 is fitted to the swash plate 11c, and the plunger 11e is in sliding contact with the thrust plate 33 via the plunger shoe 11f, thereby forming a variable displacement hydraulic pump. The movable swash plate 11c is configured to regulate the sliding amount of the plunger 11e and to adjust the discharge amount of the hydraulic oil of the hydraulic pump 11.
[0011]
Similar to the hydraulic pump 11, the hydraulic motor 12 is fitted into the oil passage plate 32, and one end of the hydraulic motor 12 is rotatably supported by the housing 31, and the output shaft 12a is fitted together with the drive shaft 12a. The plunger block 12b rotates, the plunger 12e is slidably inserted in the plunger block 12b, the swash plate 12c, and the plunger 12e that contacts the thrust plate 34 via the 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 configured as described above, 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. Is. With the above configuration, when the driving force is input to the drive 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 supplied. 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 thin plate-shaped thrust plate 33 is assembled to the movable swash plate 11c of the hydraulic pump 11, and one side surface of the thrust plate 33 (the plunger shoe 11f and The plunger shoe 11f of the plunger 11e is in sliding contact with the facing surface. One side surface of the thrust plate 33 is configured to be smooth by performing a lapping process or the like in order to reduce the sliding resistance with the plunger shoe 11f. The other side is not particularly smoothed and has a surface roughness that is greater than that of one side.
[0014]
Also, the plunger shoe 11f is formed with an oil supply hole 11g that allows communication between the inside 11k of the plunger 11e and the outside (the space in the housing 31), and hydraulic oil filled in the plunger inside 11k passes through the oil supply hole 11g. A lubricating oil film is formed by leakage between the thrust plate 33 and the plunger shoe 11f. 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 a seal portion 11h that is in close contact with the thrust plate 33 and sealed, the hydraulic oil in the plunger inner portion 11k does not leak outside more than necessary.
[0015]
As shown in FIG. 4, a circumferential groove 33 a is formed on the other side surface of the thrust plate 33. The groove 33a is located at a position corresponding to the sliding contact position of the plunger shoe 11f (when the thrust plate 33 is fitted to the movable swash plate 11c so that the other side faces the plunger shoe 11f, the plunger shoe is placed on the other side. 11f is in a sliding contact position).
[0016]
Here, since the thrust plate 33 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 are mistakenly reversed and the movable swash plate 11c is structured. Sometimes. When one side and the other side of the thrust plate 33 are reversed and assembled to the movable swash plate 11c, the plunger shoe 11f is in sliding contact with the other side, but the groove 33a is positioned 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 inside 11k and the outside of the plunger 11e communicate with each other 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 volumetric efficiency of the HST 10 is greatly reduced.
[0017]
In this manner, when one side and the other side of the thrust plate 33 are reversed and assembled to the movable swash plate 11c, the hydraulic oil leaks out of the plunger 11e by the annular groove 33a formed in the thrust plate 33, and the HST 10 By configuring so that the volumetric efficiency is lowered, even if the structured thrust plate 33 is a thrust plate 33 whose surface roughness on the other side surface is small to some extent, performance standards such as volumetric efficiency in shipping inspection and the like are cleared. Therefore, it is possible to prevent a product having the thrust plate 33 from being misoperated from being shipped. In this case, since the jet sound (abnormal sound) is generated by the hydraulic oil leaking through the groove 33a, it is possible to detect the abnormality of the product.
Therefore, over time in the marketed products, the sliding resistance between the other side surface of the thrust plate 33 and the plunger shoe 11f increases, resulting in a problem that the volumetric efficiency of the HST 10 is greatly reduced. Can be prevented.
Further, since the groove portion 33a is a single annular groove, the thrust plate 33 can be processed easily and at low cost with a lathe or the like.
[0018]
Moreover, the groove part formed in the other side surface of the thrust plate 33 can also be formed in a helical groove | channel like the groove part 33b shown in FIG.
Thus, by forming a groove formed along the substantially circumferential direction of the thrust plate 33 on the other side surface such as an annular shape or a spiral shape, one side surface and the other side surface of the thrust plate 33 are formed. It is possible to reliably discover the wrong mechanism.
[0019]
Further, as a groove portion formed on the other side surface of the thrust plate 33, a groove portion 33c formed along the radial direction of the thrust plate 33, such as the groove portion 33b shown in FIG. As in the case of the groove portions 33a and 33b formed in this manner, it is possible to reliably find an erroneous mechanism between one side surface and the other side surface of the thrust plate 33.
Note that only one groove portion 33c or a plurality of groove portions 33c can be formed.
[0020]
Further, 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 surface of the thrust plate 33, one side surface of the thrust plate 33 is similarly formed. It is possible to surely find a mistake mechanism with other aspects.
The recessed hole 33d can be easily processed at a low cost with a drilling machine or the like, and only one or a plurality of the recessed holes 33d can be formed.
[0021]
【The invention's effect】
First, as described in claim 1, on one side of the thrust plate to be assembled to the swash plate, the hydraulic CVT configurations plunger shoe provided at the plunger end is sliding contact, in the other side of the thrust plate By connecting the inside of the plunger and the outside of the plunger at a position corresponding to the plunger shoe sliding contact , if one side and the other side of the thrust plate are misconfigured, a groove is formed to identify the misconfigured product. Therefore, if one side and the other side of the thrust plate are reversed and assembled to the movable swash plate, the hydraulic oil leaks out of the plunger due to the groove formed in the thrust plate, and the volumetric efficiency of the HST is reduced. It is possible to prevent the product with the thrust plate from being misoperated from being shipped. In this case, since the jet sound (abnormal sound) is generated by the hydraulic oil leaking through the groove, it is possible to detect the abnormality of the product.
Therefore, over time in the marketed products, the sliding resistance between the other side surface of the thrust plate and the plunger shoe increases, resulting in a problem that 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 the substantially circumferential direction of the thrust plate,
When one side and the other side of the thrust plate are reversed and assembled to the movable swash plate, the hydraulic oil is drawn to the outside of the plunger by a groove formed in a substantially circumferential direction such as an annular shape or a spiral shape formed on the thrust plate. As a result, the volumetric efficiency of the HST is reduced, and it is possible to prevent shipment of a product in which the thrust plate is malfunctioning. In this case, since the jet sound (abnormal sound) is generated by the hydraulic oil leaking through the groove, it is possible to detect the abnormality of the product.
Therefore, over time in the marketed products, the sliding resistance between the other side surface of the thrust plate and the plunger shoe increases, resulting in a problem that 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 processed easily and at a low cost with a lathe or the like.
[0023]
As described in claim 3, the groove is a groove formed along a substantially radial direction of the thrust plate.
When one side and the other side of the thrust plate are reversed and assembled to the movable swash plate, the hydraulic oil leaks to the outside of the plunger by the groove formed along the substantially radial direction formed in the thrust plate, and the volumetric efficiency of the HST As a result, it is possible to prevent a product having a thrust plate from being misoperated from being shipped. In this case, since the jet sound (abnormal sound) is generated by the hydraulic oil leaking through the groove, it is possible to detect the abnormality of the product.
Therefore, over time in the marketed products, the sliding resistance between the other side surface of the thrust plate and the plunger shoe increases, resulting in a problem that the mechanical efficiency of the HST is greatly reduced. Can be prevented.
Further, since the groove is a groove formed substantially along the radial direction, the thrust plate can be processed easily and at a low cost with a lathe or the like.
[0024]
As described in claim 4, since the groove is a hollow having a diameter larger than the seal width of the plunger shoe that seals between the inside of the plunger and the outside of the plunger,
When one side and the other side of the thrust plate are reversed and assembled to the movable swash plate, hydraulic oil leaks out of the plunger due to the recessed hole formed in the thrust plate, and the volumetric efficiency of the HST decreases. It is possible to prevent a product with a misconfigured thrust plate from being shipped. In this case, since the jet sound (abnormal sound) is generated by the hydraulic oil leaking through the recess hole, it is possible to detect the abnormality of the product also by this.
Therefore, over time in the marketed products, the sliding resistance between the other side surface of the thrust plate and the plunger shoe increases, resulting in a problem that the mechanical efficiency of the HST is greatly reduced. Can be prevented.
Moreover, since the groove | channel formed in a thrust plate is a hollow, it can process a thrust plate with a drilling machine etc. easily and at low cost.
[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 the other 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 view 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 type transmission 11 Hydraulic pump 12 Hydraulic motor 11e Plunger 11f Plunger shoe 11g Oil supply hole 33 Thrust plate 33a Groove

Claims (4)

On one side of the thrust plate to be assembled to the swash plate, the hydraulic CVT configurations plunger shoe provided at the plunger end is in sliding contact, the plunger shoe sliding contact corresponding position in the other side surface of said thrust plate, a plunger internally And the outside of the plunger are connected to each other to form a groove for discriminating the erroneously structured product when one side and the other side of the thrust plate are erroneously structured. transmission.   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.   2. The hydraulic continuously variable transmission according to claim 1, wherein the groove is a hollow having a diameter larger than a seal width of a plunger shoe that seals between the inside of the plunger and the outside of the plunger.

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