JPH0577900B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application 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 pulley is provided with at least one pulley consisting of a fixed disk fixed to a rotating shaft and a movable disk rotatable relative to the rotating shaft, and a pulley is provided between the fixed disk and the movable disk. 2. Description of the Related Art A power transmission device in which power is transmitted via a compressed power transmission belt is known. For example, the special public official
This is the device described in No. 9888.

Such a power transmission device uses a power transmission belt automatic pressurizing device in which a movable disk is installed so as to be guided along a lead wire having a predetermined lead angle with respect to the 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. Therefore, the lateral pressure of the transmission belt is increased in accordance with the load applied to the output shaft of the power transmission device, so that slippage of the transmission belt is suitably eliminated regardless of elongation or wear of the transmission belt.

Problems to be Solved by the Invention Incidentally, 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, although the conventional power transmission belt clamping device described above is effective for rotation in one direction, when the rotation direction of power transmission is reversed, the movable disk becomes fixed in the opposite direction from normal rotation. The problem was 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, and its purpose is to provide a power transmission belt that can increase the clamping force according to the load during forward and reverse rotation of the power transmission device. The purpose of the present invention is to provide an automatic pressurization device.

Means for Solving the Problems The gist of the present invention to achieve the above object is to include a stationary disk fixed to a rotating shaft, and a fixed disk provided to the rotating shaft so as to be 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 fixed side disk and the movable disk, the power transmission device includes at least one pulley consisting of a movable disk and a movable disk. The automatic power transmission belt pressurizing device is of a type that increases the lateral pressure of the power transmission belt, and includes (a) a lead bushing member fitted to be relatively slidable between the rotating shaft and the movable disk; and (b) the rotating shaft. A first guide groove is formed along the first lead wire on one of the outer circumferential surface of the shaft and the inner circumferential surface of the lead bushing member, and the wire is wound in a cylindrical shape. a first spring key fixed to the other of the outer peripheral surface and the inner peripheral surface of the lead bushing member and fitted into the first guide groove, the lead bushing member being guided along the first lead wire; (c) a first stopper that prevents the movable disk from moving in the direction opposite to the belt pinching direction at a predetermined position, the movement of the lead bushing member relative to the rotating shaft in the axial direction; a second guide groove formed on one of the outer peripheral surface of the lead bushing member and the inner peripheral surface of the movable disk along a second lead wire having a lead angle opposite to that of the first lead wire; a second guide groove, which is fixed to the other of the outer circumferential surface of the lead bushing member and the inner circumferential surface of the movable disk, and is fitted into the second guide groove;
(e) axial movement of the lead bushing member relative to the movable disc, the second guide means comprising a spring key and guiding the movable disc along the second lead line; and a second stopper that prevents movement in the pressure direction at a predetermined position.

Operation and Effects of the Invention With this, when the power transmission device rotates in the normal direction, the movable disk is rotated relative to the fixed disk in the direction of the tension of the transmission belt in the normal rotation direction, so that the Since the lead bushing member is guided in the axial direction by the first guide means and is prevented from moving in the axial direction by the second stopper, the movable disk is then integrated with the lead bushing member, and the movable disk is moved in the axial direction according to the load. It approaches the fixed disk along the first lead wire, increasing the clamping force on the power transmission belt. On the other hand, 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 bushing member is first moved by the first guide means. The first
The stopper prevents axial movement, so
After that, only the movable disk approaches the fixed disk along the second lead wire by the guide means, and the clamping force on the transmission belt is increased. Therefore, in the power transmission device, even if the direction of rotation is forward or reverse, slipping of the power transmission belt is suitably suppressed by increasing the clamping force in each direction according to the load.

Furthermore, the first spring key that guides the lead bushing member along the first lead wire and the second spring key that guides the movable disk along the second lead wire are formed by winding the wire into a cylindrical shape. Because of this structure, there is no need to process it into a spiral shape to match the first guide groove or the second guide groove, and it has the advantage of absorbing micro-vibration, preventing wear, and increasing durability.

In addition, since the first spring key and the second spring key are constructed by winding a wire into a cylindrical shape, the central part is penetrated, so they can hold a predetermined amount of lubricating oil and lubricate. It has the advantage of allowing oil to pass through easily and facilitating the movement of the reed bushing member and movable disk.

Embodiment Hereinafter, an embodiment of the present invention will be described 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, an input shaft 12 and an output shaft 14
The bearings 18, 20, 2 are connected by the housing 16.
It is rotatably supported via 2 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 12 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 are provided with a pair of input-side variable pulley 34 and output-side variable pulley 36, respectively, each having a variable effective diameter.
8 is wrapped around it. The input side variable pulley 34 is a fixed disk 4 fixed to the input shaft 12.
0 and a movable disk 42 provided movably in the axial direction on the input shaft 12, and the output side variable pulley 36 includes a fixed disk 44 fixedly provided on the output shaft 14, A movable disk 46 is provided 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. The axial position of the movable disk 42 is changed by operating the handle 48. , the gear ratio of the belt type continuously variable transmission 10 is changed.

The input-side variable pulley 34 and the output-side variable pulley 36 are each provided with an automatic transmission belt pressurizing device that increases the clamping force on the transmission belt 38 according to the load regardless of the rotation direction thereof.

Next, the automatic pressurizing device provided on the output side variable pulley 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 14, has a cover member 60 attached to a bolt 62 for forming an oil-tight cylindrical space 58. A spring 66 is inserted between the spring bearing 64 fixed to the output shaft 14 and the cover member 60.
is constantly biased toward the fixed disk 44 by.

A cylindrical lead bushing member 68 is accommodated in the cylindrical space 58, and as shown in the cross section of FIG. ) is slidably fitted to the inner circumferential surface of the As shown in detail in FIG. 5, the output shaft 14
A first guide groove 70 is formed on the outer circumferential surface of the lead bushing member 68 along a first lead line having a predetermined lead angle and facing toward the output pulley 32 in a right-handed thread direction. A first key groove 74 is formed to accommodate a portion 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 68 along the lead wire in the right-handed thread direction.
A retaining ring 76 for fixing the first spring key 72 to the lead bushing member 68 is fitted on the inner peripheral surface of the lead bushing member 68 at the end on the output pulley 32 side. A stopper ring 78 that comes into contact with the retaining ring 76 to stop the lead bushing member 68 from moving in the axial direction is fitted onto the output shaft 14 . In this embodiment, the stopper ring 78 functions as a first stopper that prevents the lead bushing member 68 from moving toward the output pulley 32 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-hand thread direction, but is negative, and a lead wire in the opposite left-hand thread direction. A second guide groove 80 is formed along the two lead wires, 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 circumferential side of the second spring key 82 that is fitted into the second spring key 82 . A reed bushing member 68 housed within the cylindrical space 58 is connected to the fixed disk 44.
When it moves to the side, it reaches the end of the space 58 and comes into contact with the movable disk 46, and further movement relative to the movable disk 46 in the axial direction is prevented. 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, the second spring key 82, and the like function as a second guide means for guiding the lead bushing member 68 along the lead wire in the left-hand thread direction.
The first spring key 72 and the second spring key 82 are coil springs in which a wire is tightly wound in a cylindrical shape, so they are formed in a spiral shape to match the guide groove 70 or 80. It has the advantage of absorbing minute vibrations, preventing wear, and increasing durability. Also,
As shown in FIG. 4, the first spring key 72 and the second spring key 82 have their central portions penetrated, so that when the lead bushing member 68 moves, oil and the like can pass therethrough. It has the advantage of making it easier. Note that the first guide groove 70 and the second guide groove 80 formed along the lead wire as described above are
In FIGS. 2 and 3, they are drawn parallel to the axial direction for ease of understanding.

As shown in FIGS. 2 and 3, the output shaft 14 is provided with an oil hole 88 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, an oil hole 8 is provided in the space 58.
Lubricating oil is supplied through 8.

Belt type continuously variable transmission 1 configured as above
0, for example, during forward rotation as shown by the solid arrow in FIG. 44. When the movable disk 46 is rotated relative to the output shaft 14 in this manner, the lead bushing member 68 is guided in the axial direction by the first guide groove 70 and the first spring key 72, and is guided by the stopper portion 86 of the movable disk 46. Since the movement in the axial direction is thus prevented, the movable disk 46 will move according to the load.
moves toward the fixed disk 44 integrally with the lead bushing member 68 along the first guide groove 70, increasing the clamping force on the transmission belt 38. FIG. 3 shows this state. This kind of action occurs even when the effective diameter of the variable output pulley 36 is small, as shown in the lower part of FIG. 3, or when the effective diameter of the variable output pulley 36 is large, as shown in the upper part of FIG. But you can get the same.

On the other hand, when the rotation is reversed in the direction opposite to the arrow indicated by the solid line in FIG.
8, the output shaft 14 and fixed disk 44 rotate toward the output pulley 32 in the clockwise direction.
rotated relative to. When the movable disk 46 is rotated relative to the output shaft 14 in this manner, 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 then is guided in the axial direction by the stopper ring 78. Since the movement of the lead bushing member 68 is thereafter prevented from moving, the lead bushing member 68 is fixed integrally with the output shaft 14, and only the movable disk 46 approaches the fixed disk 44 along the second guide groove 80. The clamping force on the transmission belt 38 is increased according to the load. FIG. 2 shows this state. This effect can be obtained even when the effective diameter of the output variable pulley 36 is small, as shown in the lower part of FIG. 2, or when the output variable pulley 36 is
Even when the effective diameter is large, it can be obtained like a knot.

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

Although one embodiment of the present invention has been described above based on the drawings, the present invention can also be applied to other aspects.

For example, in the above-mentioned embodiment, the transmission belt automatic pressurizing device was provided on the output side variable pulley 36, but it may also be provided on the input side variable pulley 34, or on both input side variable pulleys 36. It's okay if it is.

Further, 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.

Furthermore, in the above embodiment, regarding the first guide means provided between the outer peripheral surface of the output shaft 14 and the inner peripheral surface of the lead bushing member 68, the first spring key 72 is inserted into the first key groove 74. Although the first spring key 72 is fixed to the lead bushing member 68 by being fitted, a member integrally protruding from the lead bushing member 68 may be fitted into the first guide groove 70. . In addition, contrary to the above, a first guide groove is formed on the inner circumferential surface of the lead bushing member 68, and the output shaft 14 is formed with a first guide groove.
A key provided on the outer peripheral surface of the key may be fitted into the first guide groove.

Similarly, regarding the second guide means provided between the inner peripheral surface of the cover member 60 and the outer peripheral surface of the lead bushing member 68, the second spring key 82
was fixed to the lead bushing member 68 by being fitted into the second key groove 84, but instead of the second spring key 82, a member integrally protruding from the lead bushing member 68 serves as the second guide. It may also be fitted into the groove 80. Further, contrary to the above, a second guide groove may be formed on the outer peripheral surface of the lead bushing member 68, and the key provided on the inner peripheral surface of the cover member 60 may be fitted into the second guide groove.

Further, in the above embodiment, a stopper ring 78 is provided to prevent the lead bushing member 68 from moving toward the output pulley 32 at a predetermined position. may be used. In short, it is sufficient as long as it prevents the lead bushing member 68 from moving toward the output pulley 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 lead bushing member 68
It is sufficient to prevent the relative movement of the movable disk 46 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 the drawing]

FIG. 1 is a diagram illustrating the main part configuration of a belt type continuously variable transmission equipped with an embodiment of the present invention. Second
3 and 3 are cross-sectional views showing the configuration of the transmission belt automatic pressurizing device provided on the output variable pulley in FIG. 1, respectively. Each shows the operating state during forward rotation. FIG. 4 is a sectional view illustrating the configuration 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: Movable disk, 6
8: Lead bushing member, 78: Stopper ring (first stopper), 86: Stopper part (second stopper).

Claims (1)

[Claims] 1. 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 side disk and a movable disk, an automatic transmission belt pressurizing device that increases the side pressure of the transmission belt according to the load. a lead bushing member fitted to be relatively slidable between the rotating shaft and the movable disk; and a first lead wire attached to one of the outer circumferential surface of the rotating shaft and the inner circumferential surface of the lead bushing member. The first guide groove is formed by a wire wound in a cylindrical shape, and is fixed to the other of the outer circumferential surface of the rotating shaft and the inner circumferential surface of the lead bushing member. a first spring key fitted into a guide groove, and a first guide means for guiding the lead bushing member along the first lead wire; and a first guide means for guiding the lead bushing member along the first lead wire; a first stopper that prevents movement of the movable disk in a direction opposite to the belt pinching direction at a predetermined position; and a first lead on one of an outer circumferential surface of the lead bushing member and an inner circumferential surface of the movable disk. A second guide groove formed along a second lead wire having a lead angle opposite to that of the wire; a second spring key fixed to the other of the circumferential surfaces and fitted into the second guide groove, the second spring key guiding the movable disk along the second lead wire;
A power transmission device comprising: a guide means; and a second stopper that prevents movement of the lead bushing member in the axial direction with respect to the movable disk, and that prevents movement of the movable disk in the belt pinching direction at a predetermined position. Transmission belt automatic pressurizing device.