JP2004232751A - Hydraulic chamber structure of continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the total length of a movable cylinder part while inexpensively securing rigidity of a centrifugal hydraulic cancel chamber with a simple structure requiring no calking in a hydraulic chamber structure of a continuously variable transmission. <P>SOLUTION: This hydraulic chamber structure of the continuously variable transmission has a main hydraulic chamber 10 surrounded by a rear surface of a movable sheave 3, an inner peripheral surface of a cylindrical sheave cylinder 6 fixed to the movable sheave 3 and a front face of an annular piston 5 arranged on the inner peripheral surface of the sheave cylinder 6 so as to slidingly contact with the outer peripheral end, and has the centrifugal hydraulic cancel chamber 11 surrounded by a rear surface of a piston 5, the inner peripheral surface of the sheave cylinder 6, and a front face of an annular balancing cap 7 locked on the inner peripheral surface rear end of the sheave cylinder 6 by a snap ring 8. A step part 15A formed in a bending shape so as to have a level difference shape in the shaft direction of a shaft 1, is arranged in the outer peripheral end vicinity of the balancing cap 7. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a hydraulic chamber structure of a continuously variable transmission provided on a rear surface of a movable sheave provided on a pulley of a belt-type continuously variable transmission and including a main hydraulic chamber and a centrifugal hydraulic cancellation chamber.
[0002]
[Prior art]
In a belt-type continuously variable transmission including a primary pulley, a secondary pulley, and a belt wound around both pulleys, each pulley is formed integrally with a shaft (primary shaft or secondary shaft) serving as a rotation shaft. The fixed sheave and the movable sheave movably provided in the axial direction of the shaft have a structure in which the belt is pressed against a V-shaped groove formed by the fixed sheave and the movable sheave. Power transmission is performed. The movable sheave of each pulley moves in the axial direction so as to be separated from and brought into contact with the fixed sheave by adjusting the hydraulic pressure in a hydraulic chamber (main hydraulic chamber) formed on the rear surface (rear surface). I have. The movement of the movable sheave increases or decreases the groove width of the V-shaped groove, adjusts the effective radius of the pulley, and changes the power transmission ratio from the primary pulley to the secondary pulley.
[0003]
In such a belt-type continuously variable transmission, since the main hydraulic chamber rotates integrally with the pulley, centrifugal force acts on hydraulic oil in the main hydraulic chamber to generate centrifugal hydraulic pressure. Due to this centrifugal oil pressure, the hydraulic pressure applied to the rear surface of the movable sheave becomes excessive, so that the movable sheave cannot be properly controlled, and there is a possibility that a response delay at the time of shifting and a decrease in belt durability may be caused. Therefore, a centrifugal hydraulic pressure cancel chamber is provided adjacent to the main hydraulic chamber and opposed to the movable sheave, and the above-described problem is avoided by canceling the centrifugal hydraulic pressure in the main hydraulic chamber.
[0004]
When a centrifugal hydraulic pressure canceling chamber is formed adjacent to the main hydraulic pressure chamber, there is, for example, a structure shown in FIG. 5 (see Patent Document 1). That is, as shown in FIG. 5, a fixed sheave 22 is fixed to a shaft (here, a secondary shaft) 21, and a movable sheave 23 is provided movably in the axial direction so as to face the fixed sheave 22. ing. On the rear (rear) side of the movable sheave 23, a piston 25 is provided fixed to the shaft 21, and a balancing cap 27 is provided so as to cover the piston 25. The end (front end) of the balancing cap 27 on the side of the movable sheave 23 is closely attached to the outer periphery of the rear surface of the movable sheave 23, and the outer periphery of the piston 25 is formed on the inner peripheral surface of the balancing cap 27 via a seal ring 32. Is in sliding contact.
[0005]
Thereby, the movable sheave 23 and the balancing cap 27 are configured as a movable cylinder portion 34 having the piston 25 therein, and are surrounded by the movable sheave 23 and the balancing cap 27 (that is, in the movable cylinder portion 34). The main hydraulic chamber 30 is formed on the movable sheave 23 side (front side) of the piston 25, and the hydraulic cancel chamber 31 is formed on the opposite side (rear side of the piston 25) via the piston 25.
[0006]
When hydraulic oil is supplied to the main hydraulic chamber 30 and the hydraulic pressure is increased, the movable sheave 23 approaches the fixed sheave 22, and conversely, when the hydraulic oil in the main hydraulic chamber 30 is removed, the movable sheave 23 is moved to the fixed sheave 22. Keep away from In addition, the hydraulic pump that supplies hydraulic oil is generally driven by an engine, and when the engine is stopped, the hydraulic pressure is reduced. In such a case, the movable sheave 23 can be pressed against the fixed sheave 22 to clamp the steel belt 24. As described above, the spring 29 is interposed between the movable sheave 23 and the piston 25.
[0007]
By the way, in this configuration, the balancing cap 27 constituting the outer shell of the centrifugal hydraulic pressure canceling chamber 31 is extended until one end thereof is in contact with the back surface of the movable sheave 23, and one end thereof is fitted into a notch 23 a provided in the movable sheave 23. It is fixed by swaging. According to such a configuration, since the outer wall extending from the side wall to the rear surface of the movable cylinder portion 34 is constituted by one member (only the balancing cap 27), the number of parts can be reduced, and the centrifugal hydraulic pressure cancel chamber can be reduced. The reliability of the rigidity and strength of the outer wall 31 can be improved.
[0008]
On the other hand, as a conventional hydraulic chamber structure of a belt-type continuously variable transmission, there is also a structure as shown in a cross-sectional view of FIG. 6 (see FIG. 2 of Patent Document 2 as a similar example). That is, as illustrated in FIG. 6, a cylindrical portion (sheave cylinder portion) 26 protrudes from the rear surface of the movable sheave 23, and the sheave cylinder portion 26 has a rear end portion provided with a flange 35 for balancing. The cap 27 is locked by a snap ring 28. Thus, the main hydraulic chamber 30 and the centrifugal hydraulic cancel chamber 31 are partitioned by the piston 25 into the rear surface of the movable sheave 23 and the movable cylinder part 34 including the sheave cylinder part 26 and the balancing cap 27 of the movable sheave 23. Is formed.
[0009]
In particular, a portion of the outer peripheral end of the balancing cap 27 which is in contact with the inner peripheral surface of the sheave cylinder portion 26 is formed by bending a flange 35 along the inner peripheral surface of the sheave cylinder portion 26. Rigidity and strength are secured so that the balancing cap 27 can sufficiently resist internal pressure strongly applied to the vicinity.
[0010]
According to such a configuration, a movable cylinder portion having high rigidity and strength can be obtained easily, and the outer peripheral portions of the sheave cylinder 26 and the balancing cap 27 are formed by the flange 35 provided at the outer peripheral end of the balancing cap 27. The rigidity and strength in the vicinity of the locking portion of the sheave cylinder portion 26 can be ensured, and deformation near the outer peripheral end of the balancing cap 27 that receives a strong hydraulic pressure due to the application of centrifugal hydraulic pressure can be suppressed.
[Patent Document 1]
JP-A-9-329208 (page 3, left column, lines 23 to 47, FIG. 1)
[Patent Document 2]
JP-A-8-14348 (FIG. 2)
[0012]
[Problems to be solved by the invention]
However, according to the conventional configuration shown in FIG. 5, caulking is required at the joint between the balancing cap 27 and the movable sheave 23, which requires caulking equipment, increases equipment cost, and reduces the durability of the caulking part. The problem is that it is difficult to secure them, and in general, the caulking operation at the time of manufacturing takes a long time, so that there is also a problem that the production efficiency is reduced.
[0013]
Further, according to the conventional configuration shown in FIG. 6, the sheave is provided by the length of the flange 35 at the outer peripheral end of the balancing cap 27, which is provided to secure the strength of the locking portion of the balancing cap 27 to the sheave cylinder 26. There is a problem that the overall length of the cylinder 26 is increased, and the movable cylinder portion 34 is enlarged in the axial direction. In particular, since the outer periphery of the rear end of the movable cylinder portion 34 must be arranged so as not to interfere with, for example, a counter gear or the like, which is disposed adjacent to the inside of the transmission case when retracted, the sheave is only the length of the flange 35. The rear end of the cylinder 26 becomes longer, and accordingly, the arrangement of the adjacent members is changed, which causes a problem that the axial length of the entire belt-type continuously variable transmission is increased.
[0014]
The present invention has been made in view of these problems, and has a simple structure that does not require caulking, is low-cost, and has a stepless length in which the entire length of the movable cylinder portion can be reduced while securing the rigidity of the centrifugal hydraulic cancellation chamber. An object of the present invention is to provide a hydraulic chamber structure of a transmission.
[0015]
[Means for Solving the Problems]
Therefore, the hydraulic chamber structure of the continuously variable transmission according to the first aspect of the present invention is a belt-type continuously variable transmission including a primary pulley, a secondary pulley, and a belt wound around the primary pulley and the secondary pulley. A rear surface of a movable sheave provided on a rear surface of a movable sheave provided on at least one of the secondary pulley and the primary pulley in a transmission, formed on an outer periphery of a shaft movably supporting the movable sheave, and a rear surface of the movable sheave An annular piston fixed to the movable sheave and an inner peripheral surface of a cylindrical sheave cylinder, and an annular piston fixed to the outer periphery of the shaft and arranged so that an outer peripheral end of the inner peripheral surface of the sheave cylinder slides on the inner peripheral surface of the sheave cylinder. And a main hydraulic chamber surrounded by the piston, a rear surface of the piston, an inner peripheral surface of the sheave cylinder, and a rear surface of the piston. A centrifugal oil pressure cancel chamber surrounded by a front surface of an annular balancing cap locked by a snap ring at a rear end of an inner peripheral surface of the sheave cylinder; and an axial direction of the shaft near an outer peripheral end of the balancing cap. A step portion which is formed so as to have a stepped shape is provided.
[0016]
It is also preferable that the balancing cap has the rear surface of the outer peripheral end locked by the snap ring, and the step portion is formed on the inner peripheral side of the outer peripheral end toward the axial rearward of the shaft. Item 2), it is more preferable that the step is formed at the outermost position as far as it does not hinder the attachment and detachment of the snap ring (Claim 3).
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[First Embodiment]
First, a first embodiment of the present invention will be described.
1 and 2 are views showing a hydraulic chamber structure of a belt-type continuously variable transmission according to a first embodiment of the present invention. FIG. 1 is a cross-sectional view showing the structure of a pulley and a hydraulic chamber, and FIG. It is an enlarged view of the locking part of a cap and a sheave cylinder, and is a comparison figure with the locking part using the conventional balancing cap with a flange.
[0018]
As shown in FIG. 1, a pulley (here, a secondary pulley) 13 of the belt-type continuously variable transmission according to the present embodiment includes a fixed sheave 2 integrally formed with a shaft (here, a secondary shaft) 1 and a shaft 1. And a movable sheave 3 mounted on the outer periphery of the shaft so as to be movable in the axial direction of the shaft 1. Hereinafter, as the description about the sliding direction and the side surface of the member including the movable sheave 3, the front or the front indicates the direction approaching the fixed sheave 2 or the fixed sheave 2 side, and the rear or rear side indicates the fixed sheave 2. 2 shows the direction away from the side or the side opposite to the fixed sheave 2.
[0019]
Both surfaces of the fixed sheave 2 and the movable sheave 3 are formed as conical surfaces, and are disposed such that their respective central axes coincide with the rotation axis of the shaft 1. Further, the movable sheave 3 has a hollow cylindrical portion whose axial center is hollowed out into a cylindrical shape, and is mounted so that the shaft 1 penetrates the hollow cylindrical portion. A V-shaped groove is formed by the conical surfaces of the fixed sheave 2 and the movable sheave 3 facing each other, and a steel belt (belt) 4 is wound in the V-shaped groove.
[0020]
An annular piston 5 is fixedly provided behind the movable sheave 3 so as to protrude from the outer periphery of the shaft 1, and a sheave cylinder 6 is mounted so as to cover the outer periphery of the piston 5. The sheave cylinder 6 has a cylindrical shape, and has a flange 6a formed at the front end thereof. The flange 6a is fixedly attached to the rear surface of the movable sheave 3 so as to be tightly joined thereto. The sheave cylinder 6 constitutes a movable cylinder portion 14 that can move in the axial direction of the shaft 1 integrally with the movable sheave 3. At the rear end of the sheave cylinder 6, a cap mounting portion 16 for mounting the balancing cap 7 is provided on the inner peripheral surface, and a cutout 17 is formed in the cap mounting portion 16. The balancing cap 7 mounted on the cap mounting portion 16 is locked to the sheave cylinder 6 by a snap ring 8 fitted into the notch 17.
[0021]
The piston 5 has an annular inner peripheral portion fixed to the outer periphery of the shaft 1, and has an outer peripheral end in sliding contact with the inner peripheral surface of the sheave cylinder 6. A seal ring 12 is provided at the joint between the piston 5 and the sheave cylinder 6 so that the sheave cylinder 6 can slide smoothly with respect to the piston 5 while maintaining liquid tightness.
[0022]
The space surrounded by the front surface of the piston 5 in the movable cylinder portion 14, the inner peripheral surface of the sheave cylinder 6, and the rear surface of the movable sheave 3 is a main hydraulic chamber 10, and the inside of the main hydraulic chamber 10 is filled with hydraulic oil. Is done. When the hydraulic pressure in the main hydraulic chamber 10 is increased, the hydraulic oil presses the rear surface of the movable sheave 3 and the movable sheave 3 moves to the fixed sheave 2 side. The sheave 3 moves to the piston 5 side.
[0023]
Further, a spring 9 is interposed between the movable sheave 3 and the piston 5 inside the main hydraulic chamber 10, so that when the hydraulic oil supply pump generally driven by the engine stops functioning at the same time as the engine stops, the spring 9 is used. 9 presses the movable sheave 3 toward the fixed sheave 2 so that the steel belt 4 is securely held between the fixed sheave 2 and the movable sheave 3.
[0024]
The balancing cap 7 has an annular shape substantially along the shape of the piston 5, and has an outer peripheral end fixed to the rear end of the inner peripheral surface of the sheave cylinder 6 by a snap ring 8 as described above.
The space surrounded by the rear surface of the piston 5, the inner peripheral surface of the sheave cylinder 6, and the front surface of the balancing cap 7 is a centrifugal hydraulic cancel chamber 11, and the centrifugal hydraulic cancel chamber 11 is always filled with hydraulic oil.
[0025]
In addition, a very small gap is provided at a portion where the inner peripheral end of the balancing cap 7 and the shaft 1 are in contact with each other so as not to interfere with each other. The hydraulic oil in the centrifugal hydraulic cancellation chamber 11 always leaks little by little, and the same amount of hydraulic oil as the leaked hydraulic oil is always supplied from an operation supply device (not shown).
The locking portion of the balancing cap 7 to the sheave cylinder 6 is formed as shown by a solid line in an enlarged sectional view of the locking portion between the balancing cap and the sheave cylinder in FIG. That is, the balancing cap 7 is locked such that the outer peripheral end abuts on the cap mounting portion 16 with the inner peripheral surface of the sheave cylinder 6, and the outer peripheral rear surface contacts the front surface of the snap ring 8. An outer peripheral portion of the balancing cap 7 is provided with a step portion 15A which is bent so as to have a step in the axial direction of the shaft 1. That is, in the vicinity of the outermost peripheral portion of the balancing cap 7 (slightly near the center), a stepped portion (step portion) 15A bent and formed in the axial direction (here, rearward) from the outermost peripheral portion is provided.
[0026]
With the configuration described above, according to the hydraulic chamber structure of the continuously variable transmission of the present embodiment, the following operations and effects can be obtained.
In other words, when the continuously variable transmission operates and the pulley (here, the secondary pulley) 13 starts rotating, the main hydraulic chamber 10 and the centrifugal hydraulic cancel chamber 11 rotate integrally with the pulley 13, so that the main hydraulic chamber A centrifugal force is generated in the hydraulic oil 10 and the hydraulic oil inside the centrifugal hydraulic cancel chamber 11. The centrifugal oil pressure acting on the hydraulic oil in the main hydraulic chamber 10 and the centrifugal oil pressure acting on the hydraulic oil in the centrifugal oil pressure cancel chamber 11 work so as to cancel each other out. The centrifugal oil pressure is canceled as a whole of the movable cylinder portion, so that movement and displacement in the shaft axis direction due to the centrifugal oil pressure do not occur.
[0027]
At the locking portion of the balancing cap 7 to the sheave cylinder 6, a large axial pressure is applied to the balancing cap 7 from the centrifugal hydraulic cancellation chamber 11 side by the pressure of the working oil including the centrifugal hydraulic pressure. Since the stepped portion 15A is formed on the outer peripheral portion of the balancing cap 7, the stepped portion 15A secures high rigidity that can resist such axial pressure and also ensures strength. Therefore, even if a large pressure is applied to the outer peripheral portion of the balancing cap 7 from the centrifugal hydraulic cancellation chamber 11 side, the balancing cap 7 is hardly deformed, and the locking state by the snap ring 8 is not affected. The balancing cap 7 is held by the sheave cylinder 6 without any trouble. Moreover, since the outer peripheral end of the balancing cap 7 is locked by the snap ring 8, there is no need for a caulking operation or a caulking device, and since the configuration is simple, the assembly is easy and the production efficiency is excellent. I have.
[0028]
Also, as shown in FIG. 2, the step length of the step 15A is shorter than the length of the flange 35 as compared with the conventional structure (shown by a chain line) in which a flange is provided at the outer peripheral end of the balancing cap 7. Since the required rigidity of the outer peripheral portion of the balancing cap 7 can be secured, the total length of the sheave cylinder 6 can be shortened by the length of the flange 35. Therefore, since the entire length of the movable cylinder portion 14 can be reduced, the movable area of the movable cylinder portion 14 can be reduced.
[0029]
[Second embodiment]
Next, a second embodiment of the present invention will be described.
3 and 4 are diagrams showing a hydraulic chamber structure of a belt-type continuously variable transmission according to a second embodiment of the present invention. FIG. 3 is a cross-sectional view showing the structure of a pulley and a hydraulic chamber, and FIG. It is an enlarged view of the locking part of a cap and a sheave cylinder, and is a comparison figure with the locking part using the conventional balancing cap with a flange. Note that, in FIGS. 3 and 4, components common to the first embodiment are denoted by common reference numerals.
[0030]
In the above-described first embodiment, the balancing cap 7 is provided with a stepped portion 15A which is bent and formed so as to have a step in the axial direction rearward on the inner peripheral side of the outer peripheral end. As shown in FIGS. 3 and 4, the balancing cap 7 is formed so that a step 15B formed near the outer peripheral end thereof has a step toward the front in the axial direction of the shaft. That is, the step portion 15B of the present embodiment is formed so that the inner peripheral side is closer to the axial front side of the shaft 1 than the outer peripheral side with respect to the outer peripheral end where the balancing cap 7 is locked by the sheave cylinder 6. I have.
[0031]
Even with such a configuration, the rigidity is ensured by the step 15B formed on the outer peripheral portion of the balancing cap 7, and the strength is also ensured. Therefore, the deformation of the balancing cap 7 is suppressed, and the balancing cap 7 is held by the sheave cylinder 6 without any trouble without affecting the locking state by the snap ring 8.
As shown in FIG. 4, the step length of the step portion 15B is shorter than the length of the flange 35 as compared with the conventional structure (shown by a chain line) in which a flange is provided at the outer peripheral end of the balancing cap 7. However, since the required rigidity of the outer peripheral portion of the balancing cap 7 can be secured, the total length of the sheave cylinder 6 can be shortened by the difference between the length of the flange 35 and the step length in the shaft axis direction. Therefore, since the entire length of the movable cylinder portion 14 can be reduced, the movable area of the movable cylinder portion 14 can be reduced.
[0032]
Although the first and second embodiments of the present invention have been described above, the present invention is not limited to each of the embodiments, and can be variously modified and implemented without departing from the spirit of the present invention. .
For example, it is preferable that the radial position where the step portion 15A formed on the balancing cap 7 is formed is set to the outermost position as far as it does not hinder the attachment and detachment of the snap ring 8. In other words, the centrifugal oil pressure acting on the hydraulic oil is greatest at the outer peripheral end of the balancing cap 7 farthest from the shaft rotation axis, so that the step portion 15A is formed at the outermost position within a range that does not hinder manufacture and assembly. Thereby, the rigidity of the outer peripheral end of the balancing cap 7 can be more effectively increased, and the strength can be secured. Therefore, deformation of the locking portion between the sheave cylinder 6 and the balancing cap 7 can be suppressed, and the locked state can be maintained.
[0033]
The snap ring 8 is attached and detached by reducing the diameter of the snap ring 8 with a tool. The range that does not hinder the attachment and detachment of the snap ring 8 is defined at the outer peripheral end of the balancing cap 7 during such work. This is a range where the stepped portion 15A does not hinder the snap ring 8 or the tool or the like whose diameter has been reduced.
In each of the above-described embodiments, the hydraulic chamber structure of the continuously variable transmission according to the present invention is applied to the secondary pulley provided on the secondary shaft. However, the hydraulic chamber structure is applied to the primary pulley provided on the primary shaft. It can also be applied.
[0034]
【The invention's effect】
As described above in detail, according to the hydraulic chamber structure of the continuously variable transmission according to the first aspect of the present invention, the balancing cap is bent near the outer peripheral end so as to have a step in the axial direction of the shaft. Since the step is provided, the rigidity and strength of the outer wall constituting the centrifugal hydraulic cancel chamber can be increased, the deformation of the locking portion between the sheave cylinder and the balancing cap can be suppressed, and the locked state can be maintained. Can be. Further, since it is not necessary to provide a flange at the outer peripheral end of the balancing cap, the overall length of the movable cylinder can be reduced. Further, since the structure is simple, the production efficiency can be improved and the production cost can be reduced.
[0035]
According to the hydraulic chamber structure of the continuously variable transmission according to the second aspect of the present invention, the balancing cap has the rear surface of the outer peripheral end locked to the snap ring, and the step formed near the outer peripheral end of the balancing cap includes: Since it is formed on the inner peripheral side of the outer peripheral end toward the axial direction rearward of the shaft, the overturn of the balancing cap is effectively prevented at the locking portion between the sheave cylinder and the balancing cap, and the overall length of the movable cylinder is reduced. Can be shortened.
[0036]
Further, according to the hydraulic chamber structure of the continuously variable transmission according to the third aspect of the present invention, the step formed near the outer peripheral end of the balancing cap is located closest to the outer periphery as long as it does not hinder the attachment and detachment of the snap ring. Because it is formed, a stepped shape can be provided at the most effective position that does not interfere with the snap ring or piston, the rigidity of the outer peripheral end of the balancing cap can be increased, and the locking between the sheave cylinder and the balancing cap The strength of the part can be maximized.
[Brief description of the drawings]
FIG. 1 is a sectional view showing a hydraulic chamber structure of a continuously variable transmission according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view (an enlarged view of a cap mounting portion 16 in FIG. 1) of a locking portion between a balancing cap and a sheave cylinder of the hydraulic chamber structure of the continuously variable transmission according to the first embodiment of the present invention; It is a comparison figure with the locking part using the conventional balancing cap with a flange.
FIG. 3 is a sectional view showing a hydraulic chamber structure of a continuously variable transmission according to a second embodiment of the present invention.
FIG. 4 is an enlarged cross-sectional view (an enlarged view of a cap mounting portion 16 in FIG. 3) of a locking portion between a balancing cap and a sheave cylinder of a hydraulic chamber structure of a continuously variable transmission according to a second embodiment of the present invention; It is a comparison figure with the locking part using the conventional balancing cap with a flange.
FIG. 5 is a longitudinal sectional view showing a hydraulic chamber structure of a conventional continuously variable transmission, and is a configuration diagram showing a configuration example in which a balancing cap has a caulking portion for a movable pulley.
FIG. 6 is a cross-sectional view illustrating a hydraulic chamber structure of a conventional continuously variable transmission, and is a configuration diagram illustrating a configuration example in which a balancing cap has a flange at an end.
[Explanation of symbols]
1 shaft 2 fixed sheave 3 movable sheave 4 steel belt (belt)
5 Piston 6 Sheave cylinder 7 Balancing cap 8 Snap ring 9 Spring 10 Main hydraulic chamber 11 Centrifugal hydraulic cancel chamber 12 Seal ring 13 Pulley 14 Movable cylinder sections 15A, 15B Step section 16 Cap mounting section 17 Notch

Claims (3)

In a belt-type continuously variable transmission including a primary pulley, a secondary pulley, and a belt wound around the primary pulley and the secondary pulley, the belt is provided on at least one of the secondary pulley and the primary pulley. Provided on the rear surface of the movable sheave
Formed on the outer periphery of a shaft that movably supports the movable sheave, the rear surface of the movable sheave, the inner peripheral surface of a cylindrical sheave cylinder fixed to the movable sheave, and fixed to the outer periphery of the shaft. A main hydraulic chamber surrounded by a front surface of an annular piston disposed so as to slidably contact an outer peripheral end with an inner peripheral surface of the sheave cylinder,
Surrounded by a rear surface of the piston, an inner peripheral surface of the sheave cylinder, and a front surface of an annular balancing cap disposed behind the piston and locked to a rear end of the inner peripheral surface of the sheave cylinder by a snap ring. Equipped with a centrifugal hydraulic cancellation chamber
A hydraulic chamber structure for a continuously variable transmission, characterized in that a stepped portion is formed near the outer peripheral end of the balancing cap so as to have a stepped shape in the axial direction of the shaft. The balancing cap has a rear surface fixed to the snap ring at an outer peripheral end, and the step portion is formed on an inner peripheral side of the outer peripheral end toward an axial rearward of the shaft. Item 2. A hydraulic chamber structure of the continuously variable transmission according to Item 1. The hydraulic chamber structure for a continuously variable transmission according to claim 1, wherein the step portion is formed at a position closest to the outer periphery as long as it does not hinder attachment and detachment of the snap ring.

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