JPH0712207A - Belt type continuously variable transmission - Google Patents

Abstract

PURPOSE:To restrain deterioration of a transmission belt due to heat in a belt type continuously variable transmission in which the transmission belt is wound extending over split pulleys on the drive side and the driven side, and the pulleys on the drive side and the driven side and the transmission belt are internally mounted in a case. CONSTITUTION:Blower blades 13 are provided along a transmission belt 8 internally mounted in a case 12, and air suction port sucking open air into the case 12 and air exhaust port exhausting the inner air of the case 12 accompanying rotational movement of the blower blades 13 are provided on the case 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt type continuously variable transmission in which a transmission belt is wound around a drive-side and passive-side split pulley, and the drive-side and passive-side split pulley and the transmission belt are housed in a case.

[0002]

2. Description of the Related Art Generally, a belt type continuously variable transmission is protected by a cover. However, when it is used as a transmission for a traveling system of a work vehicle, it may be constructed as a waterproof continuously variable transmission unit. It is advantageous in performance maintenance and assembly workability. Therefore, research has been conducted into a structure in which the drive side and passive side split pulleys and the entire transmission belt are completely enclosed in the case of a hermetically sealed structure.

[0003]

However, in the hermetically-sealed belt type continuously variable transmission, the internal temperature of the case is likely to be high due to the internal heat generated mainly by the friction between the split pulley and the transmission belt, and the deterioration of the transmission belt due to the heat is rapid. Therefore, there was room for improvement in terms of improving the durability of the transmission belt. An object of the present invention is to enable effective suppression of deterioration of the transmission belt due to heat.

[0004]

The characteristic construction of the first aspect of the present invention is a belt-type structure in which a transmission belt is wound around a drive-side and passive-side split pulley, and the drive-side and passive-side split pulley and the transmission belt are housed in a case. In the speed change device, the transmission belt is provided with blower blades, and the case is provided with an intake port for sucking outside air into the case and an exhaust port for discharging internal air of the case as the blower blades rotate.

A feature of the second aspect of the present invention is that in a belt type continuously variable transmission in which a transmission belt is wound around a drive-side and passive-side split pulley, and the drive-side and passive-side split pulley and the transmission belt are housed in a case. The belt is provided with blower blades, the circulation path for circulating and circulating the internal air of the case according to the rotation of the blower blade is connected to the case, and the forced air cooler is attached to the circulation path.

[0006]

According to the characteristic construction of the first aspect of the invention, the outside air is sucked into the case from the intake port and the internal air of the case is discharged from the exhaust port in accordance with the rotation of the blowing blade attached to the transmission belt. Without substantially impairing the enclosing function of the drive side and passive side split pulleys and the transmission belt by the case, it is possible to discharge the air heated by the internal heat generation and cool the inside of the case by the outside air. Durability can be sufficiently improved by suppressing deterioration. Further, the abrasion powder of the transmission belt can be discharged from the exhaust port, and the trouble caused by the accumulation of the abrasion powder of the transmission belt in the case can be prevented. Moreover,
It is possible to simply modify the transmission belt by attaching ventilation blades and providing an intake port and an exhaust port in the case, which is advantageous in terms of manufacturing and cost over adding a special exhaust fan.

According to the characteristic construction of the second aspect of the invention, the internal air of the case is sent to the circulation path and is cooled by the forced air cooler in accordance with the rotation of the blower blades attached to the transmission belt.
Without impairing the enclosing function of the drive side and passive side split pulleys and the transmission belt by the case, it effectively suppresses the temperature rise inside the case due to internal heat generation and suppresses deterioration due to the heat of the transmission belt to sufficiently improve durability. it can.

[0008]

As a result, the drive side and passive side split pulleys and the transmission belt are substantially enclosed by the case, but the deterioration due to the internal heat generation of the transmission belt can be sufficiently suppressed, and the durability is further improved. A belt type continuously variable transmission can now be provided.

[0009]

【Example】

(Embodiment 1) FIG. 1 shows a belt type continuously variable transmission A used as a traveling system transmission of a combine. This belt type continuously variable transmission A is interposed between an engine (not shown) and a gear transmission case M for driving a traveling device, and has an input pulley 2 for winding a transmission belt 1 from the engine and an input shaft 3 , The input gear 4 of the gear transmission case M is attached to the output shaft 5, and the drive side split pulley 6 mounted to rotate integrally with the input shaft 3 and the passive side split pulley 7 mounted to rotate integrally with the output shaft 5. The transmission belt 8 is wound around, and the movable pulley portions 6b and 7b are attached to the fixed pulley portions 6a and 7a that rotate at fixed positions on the drive side and passive side split pulleys 6 and 7 so that they can move toward and away from each other.
The movable pulley portion 6b of the drive side split pulley 6 is connected to the input shaft 3
A shift operation sleeve 10 provided with a cam mechanism 9 that slides in the axial direction is provided so that it can be rotated from the outside, and the movable pulley portion 7b of the passive side split pulley 7 is urged toward the fixed pulley portion 7a. A spring 11 is provided to change the pulley spacing of the drive-side split pulley 6 by the shift operation sleeve 10 and to reversely change the pulley spacing of the passive-side split pulley 7 for continuously variable transmission.

As shown in FIG. 2, drive-side and passive-side split pulleys 6 and 7 and a transmission belt 8 are housed in a case 12, and a blast blade 13 is attached to the transmission belt 8 so that the blast blade 13 rotates. The case 12 is provided with an intake port 15 with an air cleaner 14 for sucking the outside air into the case 12 and an exhaust port 16 for exhausting the internal air of the case 12, and a rubber cap 17 opened by wind pressure is attached to the exhaust port 16. Without substantially impairing the enclosing function of the drive-side and passive-side split pulleys 6 and 7 and the transmission belt 8 by 12, the air heated by internal heat is released to cool the inside of the case 12 by the outside air, and the transmission belt 8 Of the transmission belt 8 is discharged from the exhaust port 16 to prevent the trouble caused by the accumulation of the transmission belt abrasion powder in the case.

To form the transmission belt 8, as shown in FIG. 3, resin blocks 8b and 8c are formed on the front and back of the rubber belt 8a.
Are integrally attached with rivets 8d, and several blower blades 13 are attached with rivets 8d every other block on the front side block 8b.

(Embodiment 2) As shown in FIG.
In the belt type continuously variable transmission A similar to
Instead of the exhaust port 16 and the exhaust port 16, a circulation passage 18 for circulating and circulating the internal air of the case 12 in accordance with the rotation of the blower blade 13 is connected to the case 12, and a fincheube type air cooled by an engine cooling fan 19 is connected. The forced cooler 20 is attached to the circulation path 18, and the temperature rise in the case due to internal heat generation is suppressed without impairing the enclosing function of the drive side and passive side split pulleys 6 and 7 and the transmission belt 8 by the case 12. The transmission belt 8 is configured so as to suppress deterioration due to heat.

[Other Embodiments] Blower blades 13 are attached to the transmission belt 8.
The specific configuration of attaching the rubber belts 8e and 8f can be appropriately changed. For example, as shown in FIGS. 5 and 6, resin blocks 8f arranged on the front and back of a pair of left and right rubber belts 8e are integrally formed, and the rubber belts 8e and 8f are baked. Blower blade 1
3 may be formed. In the belt type continuously variable transmission A of the first embodiment, instead of the rubber cap 17, a damper configured to be closed by a spring and to be opened by wind pressure may be provided, and the intake port 15 and the exhaust port 16 may be provided. May be simply opened. As shown in FIG. 7, in the belt type continuously variable transmission A similar to that of the first embodiment, the intake port 15 and the exhaust port 16 are provided in the intake passage 22 of the engine 21, and upstream of the air cleaner 23 from the intake port 15. The exhaust port 16 may be connected so as to communicate with the engine 21 at a position close to the engine 21, and the pressure difference between the connection positions X and Y may be used to promote ventilation in the case 12.

It should be noted that although reference numerals are given in the claims for convenience of comparison with the drawings, the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view of a belt type continuously variable transmission according to a first embodiment.

FIG. 2 is a vertical sectional side view of the belt type continuously variable transmission according to the first embodiment.

FIG. 3 is a vertical sectional side view of the transmission belt.

FIG. 4 is a vertical sectional side view of a belt type continuously variable transmission according to a second embodiment.

FIG. 5 is a vertical sectional side view of another embodiment of the transmission belt.

6 is a sectional view taken along line BB of FIG.

FIG. 7 is a vertical sectional side view showing another embodiment of the belt type continuously variable transmission.

[Explanation of symbols]

 6 Drive side split pulley 7 Passive side split pulley 8 Transmission belt 12 Case 13 Blower blade 15 Inlet port 16 Exhaust port 18 Circulation path 20 Air forced cooler

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tsugunobu Ushida 64 Ishizukitamachi, Sakai City, Osaka Prefecture Kubota Sakai Factory Co., Ltd. (72) Mineiyoshi Motomura 64 Ishizukitamachi, Sakai City, Osaka Kubo Co. Ta Sakai Factory

Claims (2)

[Claims] 1. A drive-side and passive-side split pulley (6),
A belt type continuously variable transmission in which a transmission belt (8) is wound around (7) and the drive side and passive side split pulleys (6) and (7) and the transmission belt (8) are housed in a case (12). The transmission belt (8) is provided with a blower blade (13), and an intake port (1) for sucking outside air into the case (12) as the blower blade (13) rotates.
5) A belt type continuously variable transmission in which an exhaust port (16) for discharging the internal air of the case (12) is provided in the case (12). 2. Drive-side and passive-side split pulleys (6),
A belt type continuously variable transmission in which a transmission belt (8) is wound around (7) and the drive side and passive side split pulleys (6) and (7) and the transmission belt (8) are housed in a case (12). Therefore, a ventilation blade (13) is attached to the transmission belt (8), and a circulation path (18) for circulating and circulating the internal air of the case (12) is provided along with the rotation of the ventilation blade (13). A belt type continuously variable transmission which is connected to the case (12) and has an air forced cooler (20) attached to the circulation path (18).