JPH0328553A - Transmission belt automatically-pressurizing device for power transmission - Google Patents

Abstract

PURPOSE:To enhance clamping pressure corresponding to load during both positive and reverse rotation and restrain slip by having a movable disc integral with a lead bush member approach along the first lead during positive rotation and the movable disc only approach along the second lead during reverse rotation with a guide means, respectively to a fixed disc. CONSTITUTION:When a belt-type non-stage transmission 10 is positively rotated, a movable disc 46 is given left rotation relative to an output shaft 14 and a fixed disc 44 toward an output pulley 32, corresponding to the tension of a transmission belt 38. Next, a lead bush member 68 is guided to an axial direction by the first guide groove 70 and the first spring key 72, and prevented from an axial movement by the stopper portion 86 of the disc 46, so that the disc 46 can since then approach a disc 44 along the groove 70 integrally with the bush member 68 corresponding to lead, to enhance clamping pressure on the transmission belt 38. When reversely rotated, the disc 46 only approaches the disc 44 along the second guide groove 80 to enhance clamping pressure on the belt 38 corresponding to load.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an automatic power transmission belt pressurizing device for a power transmission device, and in particular can increase the lateral pressure of the power transmission belt according to the load in bidirectional power transmission. It is related to the device.

BACKGROUND TECHNOLOGY A system is provided with at least one boob between a fixed disk fixed to a rotating shaft and a movable disk rotatable relative to the rotating shaft, and between the fixed disk and the movable disk. A power transmission device is known in which power is transmitted via a transmission belt that is compressed by a motor. for example,
This is the device described in Japanese Patent Publication No. 46-9888. Such a power transmission device uses a power transmission belt automatic pressurizing device in which a movable disk is guided along a lead wire having a predetermined lead angle with respect to a rotating shaft. When the load increases, the movable disk rotates together with the transmission belt, rotates relative to the rotating shaft, is guided along the lead wire, and is brought closer to the fixed disk. For this reason, the lateral pressure on the transmission belt is increased in accordance with the load applied to the output shaft of the power transmission device, so slippage of the transmission belt is effectively eliminated regardless of elongation or wear of the transmission belt. Problems to be Solved by the Invention By the way, in the fields of industrial machinery and vehicles in which the above-mentioned power transmission device is used, the rotational direction of power transmission may be switched between normal rotation and reverse rotation. This is the case, for example, when agricultural machinery is switched between forward and reverse motion. However, the conventional power transmission belt clamping device described above is effective for rotation in one direction, but when the rotation direction of power transmission is reversed, the movable disk becomes fixed in the opposite direction to the normal rotation. This had the disadvantage that the transmission belt slipped away from the disk, making it impossible to transmit power.

The present invention has been made against the background of the above circumstances,
The object is to provide an automatic power transmission belt pressurizing device that can increase the clamping force depending on the load when the power transmission device rotates forward and reverse.

Means for Solving the Problems The gist of the present invention for achieving the object is to provide a stationary disk fixed to a rotating shaft, and a fixed disk that is rotatable relative to the rotating shaft and movable in the axial direction. In a power transmission device of a type in which power is transmitted via a transmission belt that is compressed between the stationary side disk and the movable disk, the power transmission device includes at least one pulley that operates from a movable disk provided therein. An automatic power transmission belt pressurizing device of the type that increases the side pressure of the power transmission belt according to the above, comprising: (a) a lead bushing member fitted between the rotary shaft and the movable disk so as to be relatively slidable; and (b) ) a first guide means provided between the outer circumferential surface of the rotating shaft and the inner circumferential surface of the lead bushing member for guiding the lead bushing member along the first lead wire on the outer circumferential surface of the rotating shaft; (C) a first stop collar that prevents the movable disk from moving in a direction opposite to the belt pinching direction in a predetermined position, which is a relative movement of the lead bushing member in the axial direction with respect to the rotating shaft; The movable disk is guided along a second lead wire provided between an outer circumferential surface of the member and an inner circumferential surface of the movable disk and having a lead angle opposite to that of the first lead wire on the outer circumferential surface of the lead bushing member. and (e) a second stopper that prevents movement of the lead bushing member in the axial direction relative to the movable disk and that prevents movement of the movable disk in the belt pinching direction at a predetermined position. It is in.

Operation and Effect of the Invention By doing this, when the power transmission device rotates in the normal direction,
By causing the movable disk to rotate relative to the fixed disk in the direction of the tension of the transmission belt in the normal rotation direction, the lead bushing member is guided in the axial direction by the first guide means and by the second stopper. Since movement in the axial direction is prevented, the movable disk then becomes integral with the reed-budge member and approaches the fixed disk along the first lead wire in accordance with the load, increasing the clamping force on the transmission belt. On the contrary, when the power transmission device is reversed, the movable disk is rotated relative to the fixed disk in the direction of the tension of the transmission belt in the reverse direction, so that the lead bush member is first guided by the first guide means. Since it is guided in the axial direction and its axial movement is prevented by the first stopper, from then on, only the movable disk approaches the fixed disk along the second lead wire by the guide means, and the movable disk approaches the fixed disk with respect to the transmission belt. Pressure is increased. Therefore, in the power transmission device, even if the direction of rotation is forward or reverse, the squeezing force is increased in each direction according to the load, so that slippage of the power transmission belt is suitably suppressed.

EXAMPLE Hereinafter, an example of the present invention will be explained in detail based on the drawings. FIG. 1 shows the main parts of a belt-type continuously variable transmission 10, which is a power transmission device according to an embodiment of the present invention. In the figure,
The input shaft l2 and the output shaft 14 are rotatably supported by the housing l6 via bearings 18, 20, 22, and 24. An input pulley 28 around which an input belt 26 is wound is fixed to the shaft end of the input shaft 12, and the input shaft l2 is rotationally driven by a motor (not shown). An output pulley 32 around which an output belt 30 is wound is also fixed to the shaft end of the output shaft 14, and a device (not shown) is rotationally driven via the output belt 30.

The input shaft 12 and the output shaft 14 have a pair of input-side variable pulleys 34 and output-side variable pulleys 3 whose effective diameters are variable.
6 are respectively provided, and a transmission belt 38 is wound around these variable pulleys 34 and 36. The input side variable booley 34 is horizontally disposed between a fixed disk 40 fixed to the input shaft 12 and a movable disk 42 provided so as to be movable in the axial direction on the input shaft l2. The rotor 36 is composed of a fixed disk 44 that is fixed to the output shaft 14 and a movable disk 46 that is provided on the output shaft 14 so as to be movable in the axial direction. The input variable pulley 34 is provided with a handle 48 for changing the gear ratio of the continuously variable transmission, and a bearing case 50 that is positioned in the axial direction as the handle 48 is operated. A bearing 52 is inserted into the bearing case 50 and is press-fitted onto the outer periphery of a cover member that is integrated with the movable disk 42, so that the axial position of the movable disk 42 can be changed as the handle 48 is operated. Accordingly, the gear ratio of the belt type continuously variable transmission lO is changed.

The input side variable boolean 34 and the output side variable boolean 36
are each provided with an automatic transmission belt pressurizing device that increases the clamping force on the transmission belt 38 in accordance with the load, regardless of the direction of rotation.

Next, the automatic pressurizing device provided on the output side variable boob 36 will be explained below.

As shown in detail in FIGS. 2 and 3, the movable disk 46, which is slidably fitted to the output shaft l4, has a cover member 60 for forming an oil-tight cylindrical space 58. It is fixed by a bolt 62 and is constantly urged toward the fixed disk 44 by a spring 66 inserted between a spring receiver 64 fixed to the output shaft 14 and the cover member 60.

A cylindrical lead bushing member 68 is accommodated in the cylindrical space 58.
As shown in the cross section of FIG. 4, is slidably fitted to the outer circumferential surface of the output shaft L4 and the inner circumferential surface of the movable disk 46 (cover member 60).

As shown in detail in FIG. 5, a first guide groove 70 is formed on the outer peripheral surface of the output shaft 14 and has a predetermined lead angle and extends along a lead line in a right-handed direction toward the output pulley 32. The inner peripheral surface of the lead bushing member 68 is formed with a first key groove 74 that accommodates a part of the outer peripheral side of the first spring key 72 that is fitted into the first guide groove 70. .

In this embodiment, the first guide groove 70, the first spring key 72, and the like function as first guide means for guiding the lead bushing member along the lead line in the right-handed thread direction. Note that the inner circumferential surface of the lead bushing member 68, at the end on the output boolean 32 side, is provided with the first
A retaining ring 76 for fixing the spring key 72 to the lead bushing member 68 is fitted onto the output shaft 14, and a retaining ring 76 abuts against the retaining ring 76 to stop the lead bushing member 68 from moving in the axial direction. A stopper ring 78 is fitted. In this embodiment, the stopper ring 78 is connected to the output bushing I132 of the lead bushing member 68.
It functions as a first stopper that prevents movement to the side.

Further, the inner peripheral surface of the cover member 60 fixed to the movable disk 46 is provided with a lead angle that has approximately the same absolute value as the lead wire in the right-handed direction, but is negative, and has a lead angle in the opposite left-handed direction. A second guide groove 80 is formed along the lead wire, and the second guide groove 80 is formed on the outer peripheral surface of the lead bushing member 68.
A second key groove 84 is formed to accommodate a part of the outer peripheral side of the second spring key 82 that is fitted into the guide groove 80. The cylindrical space is housed within 5 days. When the lead bushing member 68 moves toward the fixed disk 44, it reaches the end of the space 58 and comes into contact with the movable disk 46, so that further relative movement in the axial direction with respect to the movable disk 46 is prevented. It has become. In this embodiment, the stopper portion 86 that the lead bushing member 68 of the movable disk 46 comes into contact with functions as a second stopper. Further, in this embodiment, the second guide groove 80 and the second guide groove 80 are
A spring key 82 or the like is a second spring key for guiding the lead bushing member 68 along the lead wire in the left-hand thread direction.
Functions as a guide. The first spring key 72
Since the second spring key 82 is a coinless ring in which a wire is tightly wound in a cylindrical shape, there is no need to shape the second spring key 82 into a spiral shape so as to match the guide groove 70 or 80. It has the advantage of absorbing micro-vibration, preventing wear, and increasing durability. In addition, since the first spring key 72 and the second spring key 82 are penetrated at the center as shown in FIG. 68 has the advantage of being easy to move. Note that the first guide groove 70, second guide groove 80, etc. formed along the lead wire as described above are shown in FIGS. 2 and 3 for ease of understanding.
drawn parallel to the axial direction.

Then, as shown in FIGS. 2 and 3, the output shaft 14
is provided with an oil 688 that extends vertically through the output shaft 14 and opens at both ends of the first guide groove 70 . Thereby, the cylindrical space 58 divided into two parts by the lead bushing member 68 is communicated with each other, and the movement of the lead bushing member 68 is made easier. Usually, within the space 58,
Lubricating oil is supplied through the oil hole 88. In the belt-type continuously variable transmission 10 constructed as described above, for example, during normal rotation as shown by the solid arrow in FIG. It is rotated relative to the output shaft 14 and the fixed disk 44 in a counterclockwise rotation direction. When the movable disk 46 is rotated relative to the output shaft 14 in this way, the lead bushing member 68 is guided in the axial direction by the first guide groove 70 and the first spring key 72, and the stopper of the movable disk 46 Section 86
Since the movement in the axial direction is prevented by
The fixed disk 44 approaches the fixed disk 44 along the first guide groove 70, and the clamping force on the transmission belt 38 is increased. FIG. 3 shows this state. This kind of effect is
The same effect can be obtained even when the effective diameter of the output side variable pulley 36 is small as shown in the lower part of FIG. 3, or when the effective diameter of the output side variable pulley 36 is large as shown in the upper part of FIG. It will be done.

On the other hand, when reversing in the opposite direction to the solid arrow in FIG.
4 and fixed disk 44. When the movable disk 46 is rotated relative to the output shaft 14 in this way, the lead bushing member 68 is first guided in the axial direction by the first guide groove 70 and the first spring key 72, and is moved in the axial direction by the stopper ring 78. Since the lead bushing member 6 is blocked, the lead bushing member 6
8 is integrally fixed with the output shaft 14, only the movable disk 46 approaches the fixed disk 44 along the second guide groove 80, and the transmission belt 38 moves in accordance with the load.
The clamping force against the FIG. 2 shows this state. Such an effect can be obtained even when the effective diameter of the output side variable pulley 36 is small, as shown in the lower part of FIG.
The same effect can be obtained even when the effective diameter of the output variable pulley 36 is large as shown in the upper part of the figure.

As described above, in this embodiment, the clamping force is increased according to the load regardless of the rotational direction of power transmission, so that slippage of the transmission belt 3B is suitably eliminated. Therefore, for example, when used as a transmission for transmitting power in a vehicle, the power transmission is transmitted in forward and backward motion, and when used as a transmission for power transmission in industrial machinery, in forward and reverse rotation. Slippage of the belt 38 is eliminated.

Although one embodiment of the present invention has been described above based on the drawings,
The invention also applies in other aspects.

For example, in the above-mentioned embodiment, the power transmission belt automatic pressurizing device was provided on the output side variable pulley 36, but it may also be provided on the manual side variable pulley 34, or the input side variable pulley 34 and It may be provided on both of the output side variable booleans 3'6.

Furthermore, in the above-described embodiments, the case where the present invention is applied to the belt-type continuously variable transmission 10 has been described, but the present invention may be applied to a transmission with a fixed gear ratio.

Further, in the above embodiment, regarding the first guide means provided between the outer circumferential surface of the output shaft l4 and the inner circumferential surface of the lead bushing member 68, the first spring key 72 is inserted into the first key groove 74. Instead of the first spring key 72, a member integrally protruding from the lead bushing member 68 is fitted into the first guide groove 70. You can. Moreover, contrary to the above, a first guide groove may be formed on the inner circumferential surface of the lead bushing member 68, and the key provided on the outer circumferential surface of the output shaft 14 may be fitted into the first guide groove.

Similarly, regarding the second guide means provided between the inner circumferential surface of the cover member 60 and the outer circumferential surface of the lead bushing member 68, the second spring key 82 is fitted into the second keyway 84. Although the second spring key 82 is fixed to the node bushing member 68, a member integrally protruding from the lead bushing member 68 may be fitted into the second guide groove 80. Further, contrary to the above, a second guide groove may be formed on the outer circumferential surface of the lead bushing member 68, and the key provided on the inner circumferential surface of the cover member 60 may be fitted into the second guide groove. .

Further, in the above-mentioned embodiment, the stopper ring 78 is provided to prevent the lead bush member 68 from moving toward the output boolean 32 at a predetermined position.
Other means such as the end of the guide groove 70 may be used. In short, it is sufficient as long as it prevents the lead bush member 68 from moving toward the output bush IJ 32 at a predetermined position. Similarly, means other than the stopper portion 86 may be used to prevent relative movement of the lead bushing member 68 toward the fixed disk 44 with respect to the movable disk 46.

In short, the movable disk 46 of the lead bushing member 68
Any device may be used as long as it prevents relative movement toward the fixed disk 44 at a predetermined position.

The above-mentioned embodiment is merely one embodiment of the present invention, and various changes may be made to the present invention according to the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the main structure of a belt type continuously variable transmission equipped with an embodiment of the present invention. 2 and 3 are cross-sectional views showing the structure of the automatic power transmission belt pressurizing device installed on the variable output pulley in FIG. 1, and FIG. 2 shows the operating state during reverse rotation, Figure 3 shows the operating states during normal rotation. FIG. 4 is a sectional view illustrating the structure of the automatic transmission belt pressurizing device shown in FIG. 2 or 3. FIG. FIG. 5 is a perspective view for explaining the first and second guide means formed in the transmission belt automatic pressing device of FIG. 2 or 3. FIG. 10: Belt type continuously variable transmission (power transmission device) 44: Fixed disk 46 x movable disk 6th: Lead bush member 78: Stopper ring (first stopper) 86: Stopper part (second stopper)

Claims (1)

[Scope of Claims] The fixed side includes at least one pulley consisting of a fixed disk fixed to a rotating shaft and a movable disk provided relatively rotatably and movably in the axial direction to the rotating shaft. In a power transmission device in which power is transmitted via a transmission belt sandwiched between a disk and a movable disk,
An automatic power transmission belt pressurizing device of a type that increases the side pressure of the power transmission belt according to the load, the lead bushing member being fitted to be relatively slidable between the rotary shaft and the movable disk, and the rotary shaft and the movable disk. a first guide means provided between the outer circumferential surface of the lead bushing member and the inner circumferential surface of the lead bushing member for guiding the lead bushing member along a first lead wire on the outer circumferential surface of the rotating shaft; a first stopper that prevents the movable disk from moving in the axial direction relative to the rotating shaft at a predetermined position; a second guide provided between the inner circumferential surface of the disk and guiding the movable disk along a second lead wire having a lead angle opposite to that of the first lead wire on the outer circumferential surface of the lead bushing member; a second means for moving the lead bushing member in the axial direction with respect to the movable disk and preventing movement of the movable disk in the belt pinching direction at a predetermined position;
An automatic power transmission belt pressurizing device for a power transmission device, comprising a stopper.