JPH062748A - Belt type continuously variable transmission - Google Patents

Abstract

PURPOSE:To suppress the slip of a belt in the case where an excessive load acts on an output shaft, as for a belt type continuously variable transmission in which the movable pulley piece of a split pulley on the output side is energized to one side of a fixed pulley so that the belt winding diameter of the split pulley on the output side is automatically changed, accompanied with the change operation of the belt winding diameter of the split pulley on the input side. CONSTITUTION:A cam mechanism 19 for pressing a movable pulley piece 11b to a fixed pulley piece 11a side so that the belt winding diameter of an output side split pulley 11 is automatically operated to a speed reduction side, accompanied with the increase of the load applied on the output shaft 9 of the output side split pulley 11 is installed between the movable pulley piece 11b and an output side revolution member 18 which receives a power from the movable pulley piece 11b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a split pulley on the output side so that the belt winding diameter of the split pulley on the output side is automatically changed in accordance with a change operation of the belt winding diameter on the split pulley on the input side. Of the belt type continuously variable transmission in which the movable pulley piece is urged to one side of the fixed pulley.

[0002]

2. Description of the Related Art In the above belt type continuously variable transmission,
If an overload is applied to the rotary shaft of the split pulley on the output side due to traveling or the like, the belt of the belt type continuously variable transmission slips, which causes an inconvenience of early wear and damage to the belt.

[0003]

When the urging force of the urging spring for urging the movable pulley piece of the output side split pulley toward the fixed pulley side is increased in order to prevent the belt from slipping, the belt winding of the input side split pulley is performed. There is a disadvantage that the followability of the automatic change of the belt winding diameter of the output side split pulley due to the diameter changing operation is deteriorated. INDUSTRIAL APPLICABILITY The present invention provides a rotary shaft of an output side split pulley without deteriorating the followability of the automatic change of the belt winding diameter of the output side split pulley accompanying the operation of changing the belt winding diameter of the input side split pulley. The purpose is to suppress belt slippage when an overload is applied.

[0004]

The characteristic configuration of the present invention for achieving the above object is to automatically adjust the belt winding diameter of the output side split pulley with an increase in the load applied to the rotary shaft of the output side split pulley. A cam mechanism that presses the movable pulley piece toward the fixed pulley piece so that the movable pulley piece is operated toward the deceleration side is provided between the movable pulley piece and the output side rotation member that receives power from the movable pulley piece.

[0005]

As shown in FIGS. 1 and 2, when the rotating shaft 9 of the split pulley 11 on the output side is overloaded by running, the cam 19a formed on the outer peripheral surface of the boss portion of the movable pulley piece 11b and the output side. Spring receiver 18 as a rotating member
By the cam mechanism 19 constituted by the cam 19b formed on the inner peripheral surface of the movable pulley piece 11b, the movable pulley piece 11b is pressed toward the fixed pulley piece 11a by the relative rotation of the movable pulley piece 11b with respect to the spring receiver 18, The belt winding diameter of the side split pulley 11 is increased and automatically decelerated, so that the slip of the belt transmission device is suppressed.

[0006]

As described above, since the belt winding diameter of the output side split pulley is automatically changed according to the increase of the load and the output side split pulley is automatically decelerated, the belt slip is suppressed. As a result, early wear damage of the belt can be suppressed.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A belt type continuously variable transmission used in a combine according to an embodiment of the present invention will be described below. In Figure 3,
The power transmission of the engine 1 is input to the belt type continuously variable transmission 3 via the belt transmission device 2, and the shift output of the belt type continuously variable transmission 3 is a gear in the transmission case 4. A transmission system is configured to be transmitted to the reaper 5 and the traveling device 6 via the transmission device.

As shown in FIG. 1, the belt type continuously variable transmission device 3 is internally provided in a closed case 7 and extends over split pulleys 10 and 11 which are fitted onto an input shaft 8 and an output shaft 9, respectively. The transmission belt 12 is wound around and configured. The power from the engine 1 is transmitted via the transmission belt 2 to the input pulley 13 attached to the outside of the closed case 7 of the input shaft 8, and the input of the mission case 4 directly connected to the output shaft 9 via the coupling 14. It is adapted to be transmitted to the shaft 15.

Of the split pulleys 10 and 11 on the input side and the output side, the split pulley 10 on the input side has its fixed pulley piece 10a and movable pulley piece 10b spline-fitted to the input shaft 8. Then, the fixed pulley piece 10a is brought into contact with the case 7 against the tension of the belt 12 so that the position of the fixed pulley piece 10a is regulated, and the other movable pulley piece 10b is slid in the axial direction by the operation of the shift fork 16. It is configured to be possible.

And, the output side split pulley 11
Is a fixed pulley piece 11a in the split pulley 11.
Is fitted to the output shaft 9 so as to be relatively rotatable, and the other movable pulley piece 11b is fitted to the fixed pulley piece 11a so as to be slidable in the axial direction via a spline.
The fixed pulley piece 11a is brought into contact with the case 7 against the tension of the belt 12 so that the position of the fixed pulley piece 11a is regulated, and the other movable pulley piece 11b is a compression spring arranged on the outer periphery of the boss portion 11c. 17 is urged toward the fixed pulley piece 11a side, and the power of the belt 12 is transmitted from the movable pulley piece 11b to the compression spring 17 and
It is adapted to be transmitted to the output shaft 9 via a spring receiver 18 as an output side rotating member which is spline-fitted to the output shaft 9. When an overload due to running or the like acts on the output shaft 9 on the outer peripheral surface of the boss portion 11c of the movable pulley piece 11b of the output side split pulley 11 and the inner peripheral surface of the tubular portion 18a of the spring receiver 18, Cams 19a and 19b are provided as a cam mechanism 19 for pressing the movable pulley piece 11b toward the fixed pulley piece 11a. In this way, as the interval between the split pulleys 10 is changed by a manual operation, the interval between the output-side split pulleys 11 changes accordingly, and the continuously variable transmission operation can be performed. When an overload acts on the output shaft 9 of the belt type continuously variable transmission 3 due to a running load or the like, the cam mechanism 19 pushes the movable pulley piece 11b of the output side split pulley 11 toward the fixed pulley piece 11a. Then, the rotation of the output side split pulley 11 is decelerated,
The slip of the belt transmission is suppressed.

[Other Embodiments] In constructing the cam mechanism, as shown in FIGS. 4 and 5, a part of the outer peripheral surface of the boss portion 11c of the movable pulley piece 11b of the output side split pulley 11 is attached to the shaft center. On the other hand, the cam groove 19a ′ inclined to the cam groove 19a ′ is provided on the inner peripheral surface of the spring receiver 18.
A bolt 1 rotatably fitted with a roller r protruding into a '
9b 'may be provided and configured.

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 configurations of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is a sectional view of a belt type continuously variable transmission.

FIG. 2 is a schematic diagram of a cam mechanism.

[Fig. 3] Combined transmission system diagram

FIG. 4 is a sectional view showing another embodiment.

FIG. 5 is a plan view of the same.

[Explanation of symbols]

 10 input side split pulley 11 output side split pulley 11a fixed pulley piece 11b movable pulley piece 18 output side rotating member 19 cam mechanism

Claims (1)

[Claims] 1. A split pulley (1) on the output side according to an operation of changing a belt winding diameter of the split pulley (10) on the input side
A belt type continuously variable transmission in which the movable pulley piece (11b) of the output side split pulley (11) is biased toward the fixed pulley piece (11a) so that the belt winding diameter of 1) is automatically changed. In the above, as the load applied to the output shaft (9) of the output side split pulley (11) increases, the belt winding diameter of the output side split pulley (11) is automatically moved to the deceleration side. Cam mechanism (19) for pressing the pulley piece (11b) toward the fixed pulley piece (11a)
Is a belt type continuously variable transmission provided between the movable pulley piece (11b) and an output side rotating member (18) which receives power from the movable pulley piece (11b).