JPS634845Y2 - - Google Patents

Description

[Detailed Description of the Invention] Field of the Invention The present invention relates to an oil draining device for a V-belt continuously variable transmission suitable as an automobile transmission.

Conventional technology and its problems Conventionally, as described in Japanese Patent Application Laid-Open No. 58-42862, a cylinder chamber for moving the movable sheave in the axial direction by hydraulic pressure is provided behind the movable sheave of the driving pulley and the driven pulley. One that is installed in one piece is known.

However, in this structure, there is a problem in that a part of the oil in the cylinder chamber leaks out onto the belt transfer surface through the inner diameter portion of the boss of the movable sheave. In this case, it may be possible to prevent oil from leaking by installing an oil seal between the inner diameter of the boss of the movable sheave and the shaft, but the movable sheave and shaft often slide against each other to control the pulley ratio. Even if you seal it with an oil seal, it is not possible to completely prevent oil leakage. Generally, in continuously variable transmissions that use metal V-belts, the V-belt must be constantly lubricated, so even if oil leaks, there is no problem.
In continuously variable transmissions that use resin V-belts or rubber V-belts, if oil adheres to the belt transfer surface, the frictional resistance between the V-belt and the belt transfer surface will be extremely reduced, making it impossible to obtain sufficient transmission torque. It disappears. Therefore, it is necessary to prevent oil from adhering to the belt transfer surface as much as possible.

Purpose of the invention The present invention was made in view of such conventional problems, and its purpose is to provide an oil draining device for a V-belt type continuously variable transmission that prevents oil from adhering to the belt transfer surface. be.

Structure of the Invention In order to achieve the above object, the present invention includes a cylindrical boss integrally protruding from the inner diameter part of the movable sheave that can be inserted into and removed from the boss inner diameter part of the fixed sheave, and the boss end face of the movable sheave is It is located within the inner diameter of the boss of the fixed sheave within the entire stroke range of the movable sheave, and the inner diameter of the boss of the fixed sheave is provided with a recess and an oil drain hole that communicates with the outside of the belt transfer surface. In other words, the oil leaking from the inner diameter side of the movable sheave is guided from the inner surface of the boss of the movable sheave to the inner diameter part of the boss of the fixed sheave, and is further discharged from the recessed part of the inner diameter part of the boss to the outside of the belt transfer surface through the oil drain hole. This is what I did.

DESCRIPTION OF THE EMBODIMENTS FIG. 1 shows an example of a continuously variable transmission according to the present invention, which comprises a driving pulley 1, a driven pulley 10, and an endless V-belt 50 wound between these pulleys. It is equipped with The drive-side pulley 1 has a fixed sheave 3 fixed to the drive shaft 2 and a movable sheave 4 that is movable relative to the drive shaft 2, making the pulley diameter variable. A torque cam 5 and a torsion spring 6 are provided to provide a sheave thrust commensurate with the torque.

Similarly to the driving pulley 1, the driven pulley 10 also has a
A fixed sheave 12 fixed to the driven shaft 11 and a movable sheave 13 that is movable in the axial direction with respect to the driven shaft 11.
It has FIG. 2 shows a specific configuration of the driven pulley 10. In the figure, the upper half of the driven shaft 11 has a minimum pulley diameter,
The lower half shows the pulley diameter at its maximum. The fixed sheave 12 is splined to the end of the drive shaft 11 and coupled with a rotation stopper nut 14.
A boss 16 that can be freely inserted into and removed from the inner diameter of the boss 15 of the fixed sheave 12 is integrally protruded on the inner diameter of the movable sheave 13 . Vertical groove 1 provided on the outer peripheral surface
By disposing a plurality of balls 19 between the movable sheave 13 and the driven shaft 11, the movable sheave 13 is movable only in the axial direction with respect to the driven shaft 11. The end face 16a of the boss 16 of the movable sheave 13 is located within the inner diameter of the boss 15 of the fixed sheave 12 throughout the entire stroke range of the movable sheave 13, and even during the maximum stroke of the movable sheave 13 (upper half in FIG. 2). , bosses 15 and 16 overlap by a length l. Note that an oil seal 20 is arranged inside the tip of the boss 16 of the movable sheave 13,
On the other hand, on the inner diameter part of the boss 15 of the fixed sheave 12,
The recess 21 and the belt transfer surface 12a from the recess 21
An oil drain hole 22 communicating with the outside is formed.

A hydraulic cylinder chamber 23 is integrally provided at the back of the movable sheave 13.
Hydraulic pulley ratio control means 24
(See FIG. 1), the movable sheave 13 is moved in the axial direction, and the pulley ratio (speed ratio) between the driving side and the driven side can be changed steplessly. The concrete structure of the hydraulic pulley ratio control means 24 includes, for example, a pitot tube that detects the engine rotation speed, a cam that interlocks with the throttle opening, and a pitot tube as described in Japanese Patent Application Laid-Open No. 58-42862. It may be configured with a hydraulic control valve that controls the pulley ratio based on the hydraulic signal from the pipe and the displacement signal from the cam.
Also, any other hydraulic control method may be used.

By the way, even when the oil pressure to the cylinder chamber 23 is zero, oil pressure is generated in the cylinder chamber 23 due to centrifugal force based on the rotation of the driven pulley 10, and this oil pressure moves the movable sheave 13 and changes the pulley ratio. There is a risk of In order to eliminate this imbalance in the pulley ratio, hydraulic balance chambers 25 and 26 are provided on the inner diameter side and rear side of the cylinder chamber 23. The cylinder chamber 23 and the inner balance chamber 25 are partitioned by a first diaphragm 27,
3 and the rear balance chamber 26 are partitioned by a bent fixed piston 28 fixed to the driven shaft 11, and the rear balance chamber 26 and the outside are partitioned by a second diaphragm 29. Note that oil pressure is applied to the cylinder chamber 23 from the hydraulic pulley ratio control means 24 through an oil passage 30, while a lubricating oil passage 31 communicates with the inner balance chamber 25.
And both balance chambers 25 and 26 are fixed pistons 28
The two communicate with each other via a communication path 32 provided in the.

Here, the function of the balance chambers 25 and 26 will be explained with reference to FIG. Now, the driven pulley 10
When the hydraulic pressure acting on the cylinder chamber 23 is zero while the is rotating, hydraulic pressure corresponding to the centrifugal force is generated in the cylinder chamber 23, and this hydraulic pressure causes the movable sheave 13 to move toward the fixed sheave 12 side with a force of _F1. (towards the left in Figure 3). On the other hand, hydraulic pressure is also generated by centrifugal force in the balance chambers 25 and 26 that rotate integrally with the cylinder chamber 23, and this hydraulic pressure causes the inner balance chamber 25 to push the movable sheave 13 to the left in FIG. 3 with a force of _F2 . The rear balance chamber 26 has a movable sheave 1
Push 3 towards the right in Figure 3 with the force of F ₃ . At this time,
Since the sum of the areas of the hydraulic working surface of the cylinder chamber 23 and the hydraulic working surface of the inner diameter side balance chamber 25 is set to be approximately equal to the hydraulic working area of the back side balance chamber 26, the hydraulic pressure due to the centrifugal force is balanced on the left and right sides. The pulley ratio will not go out of order.

In addition, although the case where the oil pressure acting on the cylinder chamber 23 is zero is described above, even when some oil pressure is acting on the cylinder chamber 23 from the hydraulic pulley ratio control means 24, the oil pressure fluctuation due to the centrifugal force is can be balanced on the left and right in the same way as above.

As mentioned above, the cylinder chamber 23 and the back side balance chamber 26 are sealed with the diaphragms 27 and 29, so there is no fear of oil leakage, but the inside of the inner diameter side balance chamber 25 is sealed with the oil seal 20. Although it is, there is some oil leakage. However, since the end surface 16a of the boss 16 of the movable sheave 13 is always located within the boss 15 of the fixed sheave 12, even if oil leaks from the oil seal 20, this oil will be fixed as shown by the arrow in FIG. The oil accumulates in a recess 21 formed in the inner diameter of the boss 15 of the sheave 12, and is further discharged to the outside via the oil drain hole 22. In other words, oil never adheres to the belt transfer surfaces 12a and 13a of the fixed sheave 12 or the movable sheave 13, and the oil never adheres to the belt transfer surfaces 12a and 13a of the fixed sheave 12 or the movable sheave 13, and
The frictional resistance with 2a and 13a is not reduced. Therefore, if this device is applied to a continuously variable transmission using a resin V-belt or a rubber V-belt,
Extremely effective.

In the above embodiment, a case has been described in which leaked oil is discharged from the balance chamber 25 provided on the inner diameter side of the cylinder chamber 23, but the invention is not limited to this, and the cylinder chamber 23 is not separated from the balance chamber 25 by a diaphragm or the like. The present invention can also be applied to a structure in which the chambers 23 and 25 are integrated to form a cylinder chamber.

Further, in the above embodiment, a mechanical tension loading means such as a torque cam 5 is provided on the driving pulley 1, and a cylinder chamber 23 is provided on the driven pulley 10. 1 may be provided with a cylinder chamber 23, and the driven pulley 10 may be provided with a mechanical tension loading means, and furthermore, both the driving pulley and the driven pulley may be provided with the cylinder chamber 23.

Effects of the Device As is clear from the above explanation, according to the present invention, oil leaking from the inner diameter side of the movable sheave is guided from the inner surface of the boss of the movable sheave to the inner diameter portion of the boss of the fixed sheave, and is further guided to the inner diameter portion of the boss of the fixed sheave. Since the oil is drained out of the belt transfer surface through the oil drain hole, oil never adheres to the belt transfer surface. Therefore, sufficient transmission torque can be obtained without reducing the frictional resistance between the V-belt and the belt transfer surface.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the V-belt type continuously variable transmission according to the present invention, Fig. 2 is a detailed sectional view of the driven pulley,
FIG. 3 is a schematic diagram showing the function of the balance chamber. 1... Drive side pulley, 10... Driven side pulley,
12...Fixed sheave, 12a...Belt transfer surface,
13...Movable sheave, 15,16...Boss, 20
... Oil seal, 21 ... Recess, 22 ... Oil drain hole, 23 ... Cylinder chamber, 25, 26 ... Balance chamber, 27, 29 ... Diaphragm, 28 ... Fixed piston.

Claims (1)

[Scope of utility model registration request] In a V-belt continuously variable transmission in which a hydraulic cylinder chamber for moving the movable sheave in the axial direction is integrally provided in at least one of the movable sheaves of the driving pulley or the driven pulley, an inner diameter portion of the movable sheave is provided. , a cylindrical boss that can be freely inserted and removed is integrally provided within the inner diameter of the boss of the fixed sheave, and the end face of the boss of the movable sheave is located within the inner diameter of the boss of the fixed sheave within the entire stroke range of the movable sheave,
An oil draining device for a V-belt type continuously variable transmission, characterized in that a recess and an oil drain hole communicating with the outside of the belt transfer surface are provided in the inner diameter portion of the boss of the fixed sheave.