JPS62101968A - Cooling construction for belt in v belt type continuously variable transmission - Google Patents

Abstract

PURPOSE:To enable a V belt to be effectively cooled, by forming an air passage, opened to space formed between a fixed sheave and a variable sheave, in a rotary shaft. CONSTITUTION:Space 8, being formed between a fixed sheave 5 and a variable sheave 6, is opened also to an inner side in the radial direction. A driving shaft 4 forms plural holes 7a in the radial direction, and an opening end of these holes communicates with the space 8. While a hole 7b, opening its one end to an end surface 4a of the driving shaft 4 and connecting the other end with the hole 7a, is formed in the axial direction of the driving shaft 4. An air stream in the centrifugal direction is generated in the space 8 by rotating a driving side pulley 1 at a high speed, and the outside air, being allowed to flow into the space 8 through an air passage 7 in the driving shaft and flow in the centrifugal direction, cools the both sheaves 5, 6 and a V belt by the air stream.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a belt cooling structure in a V-belt continuously variable transmission used in automobiles, etc. This relates to a structure for cooling a V-belt.

(Prior Art) FIG. 3 shows a conventional structure of a drive-side pulley of a V-belt type continuously variable transmission. In this conventional example, a is a fixed sheave fixed to a drive shaft (rotating shaft) b, and C is a movable sheave supported on the drive shaft so as to be movable in the axial direction, and these constitute a drive pulley. There is. An endless V-bell) d is wound between both inner surfaces of these sheaves a and c, and both sheaves a and
, c is also open radially inward.

Due to the rotation of the drive shaft, a centrifugal airflow is generated in the drive side boob, but the air flow to the inner peripheral part of the space e, that is, the part located radially inward from the endless V-bell d. The air flow is weak because the supply is blocked by both sheep a, c and the drive shaft.

(Problem to be solved by the invention) By the way, in the V-belt type continuously variable transmission, as the movable sheave C moves in the axial direction, the endless (bell) d is in frictional contact with the inner surfaces of both sheaves a and c. Since the position of the belt changes frequently and is pressed between the two sheaves a and c with a strong force, a large amount of frictional heat is generated, causing the endless V-belt d and both sheaves a and c to be in a high temperature state.

When the endless V-belt d is made of rubber or synthetic resin, there is a problem that it is easily thermally deteriorated and deformed by the frictional heat, and its durability is impaired.

In this way, preventing thermal deterioration and thermal deformation of the endless V-belt is an important issue, and for this purpose, it is necessary to efficiently cool the endless V-belt, but the above conventional example does not address this point. No ingenuity has been put into it. As will be described later, the present invention smoothes the flow of centrifugal airflow that occurs when the pulley rotates, and uses this cooling effect to prevent thermal deterioration and thermal deformation of the endless V-belt.However, in the conventional example, as described above, However, the airflow in the centrifugal direction was so weak that almost no air cooling effect could be expected.

(Means for Solving the Problems) In order to solve the above-mentioned problems, the present invention provides a structure between the inner surfaces of a fixed sheave fixed to a rotating shaft and a movable sheave supported movably in the axial direction on the rotating shaft. In a V-belt type continuously variable transmission in which an endless V-belt is wound and a space formed between a fixed sheave and a movable sheave is also opened radially inward, one end or the end face of the rotating shaft or its An air passage is formed in the rotating shaft, the air passage being open to the vicinity and the other end being open to the space (Function) According to the above structure, the air passage is formed between the fixed sheave and the movable sheave. The space communicates with the outside via an air passage formed in the rotating shaft.

Accordingly, a centrifugal airflow is generated in the space by the rotation of the pulley, and when the center of the space becomes negative pressure, outside air flows into the center through the air passage. Therefore, the airflow in the centrifugal direction is secured with a sufficient amount of cooling air, and flows smoothly in the centrifugal direction while cooling the endless belt and both sheaves which are in a high temperature state.

(Example) FIG. 2 shows an example of a V-belt type continuously variable transmission. This continuously variable transmission includes a driving pulley 1, a driven pulley 2, and an endless V-belt 3 wound between these pulleys.

The drive pulley 1 includes a fixed sheave 5 fixed to a drive shaft (corresponding to a rotating shaft in the scope of the utility model registration claims) 4, and a movable sheave 6 movable in the axial and rotational directions with respect to the drive shaft 4. The diameter of the pulley is variable, and a torque cam is installed behind the movable sheave 6! 9 are installed.

The driven pulley 2 is a fixed sheave 1 fixed to the driven shaft IO.
1 and a movable sheave 12 that is movable in the axial direction with respect to the driven shaft 10, the pulley diameter is variable. Behind the movable sheave 12, a hydraulic pulley ratio control means 13 is disposed.

By moving the movable sheave 12 in the axial direction using the hydraulic pulley ratio control means 11, the pulley ratio between the driving side and the driven side, and thus the speed ratio, can be changed steplessly.

FIG. 1 shows the drive pulley l in detail. The fixed sheave 5 is formed into a conical shape and is fixed to the outer periphery of the drive shaft 4 via a boss 14. A movable sheave 6, which is symmetrical to the fixed sheave 5, is fixed to a boss 15 that is supported movably in the axial and rotational directions with respect to the drive shaft 4.

Space 8 formed between fixed sheave 5 and movable sheave 6
is also open radially inward. A plurality of holes 7a, 7a are formed in the drive shaft 4 in the radial direction, and their open ends communicate with the space 8. On the other hand, a hole 7b is formed in the axial direction of the drive shaft 4, one end of which is open to the end surface 4a of the drive shaft 4, and the other end of which communicates with the holes 7a, 7a. These holes 7b and 7a constitute an air passage 7 whose one end is open to the end surface 4a and the other end is open to the space 8.

Thus, due to the high speed rotation of the driving pulley 1, a centrifugal airflow (indicated by the arrow in FIG. 1) is generated in the space 8 formed between the fixed sheave 5 and the movable sheave 6. Along with this, the center of the space 8 becomes under negative pressure, so the outside air flows into the space 8 through the air passage 7 in the drive shaft 4 (as shown by the arrow in FIG. 1), and then flows in the centrifugal direction. .

At this time, both sheaves 5. are in a high temperature state due to frictional contact.
6 and the endless V-belt 3 are cooled by the air flow.

The present invention can be configured in various ways other than those shown in the above embodiments. For example, in the above embodiment, one end of the air passage 7 is open to the end surface 4a of the drive shaft 4;
It may be open near point a. Further, although the above embodiment is an example in which the present invention is applied to the driving pulley 1, it may also be applied to the driven pulley 2.

(Effects of the Invention) Since the present invention has the above-described structure and operation, the endless V-belt can be effectively cooled and its durability can be improved.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional side view showing an embodiment of the present invention, and FIG. 2 is a V
A schematic diagram showing the overall configuration of a belt-type continuously variable transmission, and FIG. 3 is a longitudinal sectional side view showing the main parts of a conventional example.

Claims (1)

[Claims] (1) An endless V-belt is wound between the inner surfaces of a fixed sheave fixed to the rotating shaft and a movable sheave supported movably in the axial direction by the rotating shaft, and between the fixed sheave and the movable sheave. In a V-belt continuously variable transmission in which the space formed is open to the radially inward side, the air passage whose one end is open to or near the end surface of the rotating shaft and the other end is open to the space is A V characterized by being formed within the rotating shaft.
Belt cooling structure for belt type continuously variable transmission.