JPH0226357A - Speed increase and decrease device - Google Patents

Abstract

PURPOSE:To make stable and high precision contact of both a driven roller and a center roller by putting a turnable eccentric bush between the driven roller and a revolution support shaft, and mounting a pressure ring and a fixing ring having the tapered faces in contact with the driven roller and setting a means which gives pressure axially to the pressure ring from the input side. CONSTITUTION:If a driven roller 7 makes uneven contact with a center roller 6 since the accuracy of the pitch circle of a revolution support shaft 8 is unsatisfactory or the center point of this pitch circle is offset from the axis of the output turning shaft is, the pressure member 21 of a pressure means presses a pressure ring 20 toward a fixed ring 19. By this pressure the driven roller 7 is forced to make contact with the opposing tapered surfaces 19a and 20a which are the internal surfaces of the pressure ring 20 and the fixed ring 19, to press them toward the center roller 6, whereby automatically turn an eccentric bush 9 which turnably receives the revolution support shaft 8. The eccentric position thereof may be corrected to have both the driven roller 7 and the center roller 6 make contact with each other under even pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a planetary roller type speed-up/deceleration mechanism which is also suitable for use in an electric pan head for controlling the direction of a camera mounted on a tripod, for example.

[Conventional technology]

In order to capture the ecology of wary wild animals such as wild birds, we can photograph them from a distance with a camera equipped with a super-telephoto lens.In addition, if there are restrictions due to location, we can take photographs near the habitat of the wild animal or the place where it has arrived. It is also often the case that a camera is set up and the person taking the image remotely performs the imaging from a distance. In the case of this remote control, for example, an electric pan head having the structure shown in FIG. 4 is used. That is, the horizontal rotation unit includes a horizontal rotation unit C and a vertical movement unit connected to an electric pan head A mounted on a tripod B installed on the ground surface, and a built-in electric drive motor and speed reduction mechanism. By part C, the upper vertically moving part support E and the vertically moving part attached to the same vertically moving part support E perform horizontal rotation. Due to the rotating part, the camera mount F attached to the vertically moving part and the camera G placed on and attached to the same camcorder mount F move up and down. These directional operations of the camera, including horizontal rotation and vertical movement, are performed by operating the operation panel H from a remote location.

By the way, as mentioned above, the electric pan head moves the camera in the shooting direction at a constant, decelerated speed, but the rotational speed of the built-in motor is slowed down to achieve the required moving speed in the shooting direction. In place of the conventional speed reducer configured by a combination of many gears, a planetary roller type speed reducer that can obtain a large reduction ratio in one step has recently been proposed as a speed reducer for achieving this.

This known planetary roller speed reducer has a configuration as shown in FIG. A center roller 23 as a sun roller is constructed at the output side tip of the input rotating shaft 22, and three piece-shaped driven rollers 24 as so-called planetary rollers are arranged evenly in contact with the concentric roller 23. The driven roller 24 is rotatably supported by a rotation support shaft 25 via a bearing. The rotation support shaft 25 is fixed to an output board 27 formed coaxially with the output rotation shaft 26, and the driven roller 24 revolves around the center roller 23 while rotating due to the rotation of the input rotation shaft 22, and is decelerated. The resulting rotation is transmitted to the output shaft 26.

These mechanisms are housed together in the housing 28.

In such a speed reducer, in order to ensure sufficient contact between the center roller 23 and each driven roller 24, there is a cross section U between the inner wall of the housing 28 and the outer end of the driven roller 24.
A letter-shaped outer ring 29 is arranged, and a fixing ring 30 and a pressure ring 31 are arranged to sandwich the outer ring 29,
When the housing lid 32 is attached, the outer circumferential ring 29 is pressed on both sides by the fixing ring 30 and the pressure ring 31, and its bottom part is pushed out to press the driven roller 24 toward the center of the center roller 23. That is, as shown in FIG. 6, by applying pressure in the X direction to both sides of the outer ring 29, the U-shaped cross section is deformed, and the force that causes the bottom to protrude in the X direction is used as a pressing force on the driven roller 24. are doing.

[Problem to be solved by the invention]

However, in this conventional technology, three driven rollers 24 that contact the center roller 23 of the input rotating shaft 22
are supported by concentric rotational support shafts 25 forming a central axis, and these three rotational support shafts 25 are connected to the output rotational shaft 2.
6, the center roller 23 is fixed to the output board 27 coaxially with the rotary support shaft 25. Therefore, if the positioning accuracy of the rotation support shaft 25, that is, the dimensional accuracy including the center position of the pitch circle of the rotation support shaft 25 is poor, the center roller 23 This causes an imbalance in contact pressure between the driven rollers 24 and the driven rollers 24, causing abnormal wear on some of the driven rollers 24 and insufficient contact on some of the driven rollers 24.
This causes a problem in that the rotation of the reducer becomes distorted, resulting in a decrease in the rotation accuracy of the entire speed reducer, poor rotation, and even inability to rotate.

In addition, since the pressing force due to the deformation of the entire outer circumferential ring 29 that presses the driven roller 24 against the center roller 23 is large, the wear of each contact area is large, especially when the rotating support shaft 2 as described above
If there is poor positioning accuracy in step 5, abnormal vibration or creaking will occur in the transmission path from the driven roller 24 to the rotation support shaft 25 to the output board 27, and abnormal wear in some of the driven rollers 24 will be promoted. However, there was a problem in that the rotation failure occurred at an early stage.

In order to deal with this problem, there is an idea to replace the center roller 23 with one whose dimensions are changed in accordance with the pitch circle of the rotary support shaft 25, but in this case, the reduction ratio, that is, the performance of the reduction gear, may be changed. I don't like it because it will change. Also,
There is an idea to provide play between the rotation support shafts 25 of the driven rollers 24 to absorb and correct the uneven contact pressure.
In this case, during rotational drive, a so-called bank crash similar to that seen in gear transmission will occur, which is not preferable for applications such as electric pan heads for camera cameras.

In view of the above circumstances, an object of the present invention is to enable the planetary rollers, that is, the driven rollers to press the sun roller, that is, the center roller, evenly and evenly, without worrying about the positioning accuracy of each rotating support shaft, and to The purpose of the present invention is to provide a planetary roller type speed increaser/decelerator that can maintain rotation accuracy for a long period of time and has low cost.

[Means to solve the problem]

In order to achieve this object, the present invention provides a center roller formed coaxially with an input rotation shaft, a driven roller that is formed coaxially with the output rotation shaft and revolves around the center roller while rotating in contact with the center roller, and a driven roller formed coaxially with the output rotation shaft and said roller. A planetary roller type speed increase/reducer comprising an output board fixing a rotation support shaft of a driven roller, the driven roller being fitted via a bearing to the rotation support shaft fitted with an eccentric bushing so as to be freely rotatable. There is also a pressure ring and a fixed ring having tapered surfaces on the inner periphery that contact the driven roller oppositely from the axial input side and the axial output side, and the pressure ring is applied in the axial direction from the input side. The present invention proposes a speed increase/reduction gear equipped with a driven roller pressurizing means consisting of a pressurizing member.

[Effect]

In the present invention configured as described above, when rotation is applied to the input rotating shaft by driving an externally attached motor,
A driven roller in contact with the center roller rolls, and the output substrate fixing the rotational support shaft of the driven roller, and thus the output rotation shaft, rotates concentrically and in the same direction as the center roller.

That is, the driven roller greatly decelerates the input rotation speed and transmits it to the output rotation shaft using a planetary roller mechanism in which the driven roller revolves around the center roller while rotating.

In addition, the pressure ring is urged toward the fixed ring by the pressure force of the pressure member, and each driven roller is brought into contact with the opposing tapered surfaces of the pressure ring and the fixed ring inner circumference to press the center roller. Each driven roller is pressed and biased by the driven roller pressure means so as to maintain normal contact with the center roller.

Furthermore, there may be poor positioning accuracy of the rotation support shaft of the driven roller, that is, poor accuracy of its pitch circle, or misalignment between the center of the pitch circle and the axis of the output rotating shaft, resulting in uneven contact between the driven roller and the center roller. The eccentric bushing, which is rotatably inserted into the rotating support shaft, automatically rotates under the pressure of the above-mentioned pressure means, and each driven roller and the center roller are brought into contact with each other with equal contact pressure. Correct the eccentric position so that they make contact.

In addition, in the above mechanism, a motor is attached to the output side,
By extracting rotational output from the input side, the purpose of the speed increaser can be achieved.

〔Example〕

The present invention will be explained below with reference to the drawings. FIG. 1 is a side cross-sectional view of the speed increaser/deceleration gear of the present invention, and FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG.

First, to explain the structure, the speed reducer 1 of the present invention has its mechanism compactly housed in a housing 2 and a housing lid 3, and a drive motor (not shown) is installed outside the housing 2. An input rotating shaft 4 connected to the motor is inserted through the housing lid 3 and is rotatably held by a ball bearing 5. A small-diameter center roller 6 is coaxially and integrally formed at the output end of the input rotating shaft 4. The concentric roller 6 has an arcuate groove 6a on its outer peripheral surface, and three driven rolls 7 whose outer periphery forms a convex surface 7a are arranged in contact with the groove 6a. The driven roll 7 is constructed by fitting an eccentric bushing 9 to a rotating support shaft 8 serving as a central axis, and interposing a needle bearing 10 on the outer periphery of the eccentric bushing 9.
This is a configuration in which the two are fitted together. In order to prevent the eccentric bushing 9 from being pulled out, a ring 11 is attached to the end to prevent the bushing from being pulled out.
, washer 12 is provided. The three driven rollers 7 are
The rotation support shafts 8 are inserted into holes evenly drilled in the output board 13 facing the center roller 6 so as to be evenly arranged around the outer circumference of the center roller 6, and the output is adjusted by tightening the naphts 14. It is fixed to the substrate 13. An output rotation shaft 15 is coaxially and integrally formed on the output side of the output board 13 in the axial direction, and the output rotation shaft 15 is rotatably held in the housing 2 by two ball bearings 16A and 16B. The ring 17 and the washer 18 are designed to prevent the drawer from falling off.

Further, a fixing ring 19 is provided inside the housing 2, and its inner circumferential tapered surface 19a is connected to the outer circumferential concave surface of the driven roller 7.
a from the output side, and the inner tapered surface 20a is in contact with the convex outer surface 7a of the driven roller rough from the input side, opposite to the fixed ring 19, and is slidable. A pressurizing ring 20 may be provided inside.

A pressurizing spring 21 as a pressurizing member is brought into contact with the input side side surface of the pressurizing ring 20, and a housing cover 3 is applied to the housing 2, so that the pressurizing spring 21 outputs the pressurizing ring 20 in the axial direction. The pressing force is applied at the contact portion between the tapered surface 20a of the pressure ring 20 and the convex surface 7a of the driven roller 7, and the vertical component force is applied to the center roller 6 of the driven roller 7. It is used as pressurizing force.

The speed reducer of the present invention is constructed as described above, and the fixing ring 19 is fitted into the housing 2 in which the ball bearings 16A and 16B are installed in advance, and the driven roller 7 in which the eccentric bushing 9 and the like are installed is attached to the output. Incorporate the output board 13 with the rotating shaft 15, and pressurize the ring 20.
After fitting the pressurizing spring 21 to the pressurizing ring 20, the input rotation shaft 4 and the center roller 6 are assembled in advance, and the housing cover 3 is attached to the housing 2 and fixed. It will be done.

In the above embodiment, when the input rotation shaft 4 is rotated by the drive of the external motor, the center roller 6, which is a so-called sun roller, formed at the tip of the input rotation shaft 4 rotates, and the outer peripheral recess of the concentric roller 6 rotates. The three driven rollers 7, which are in contact with the groove 6a with their outer circumferential convex surfaces 7a, each rotate around rotational support shafts 8 in the opposite direction to the center roller 6 as so-called planetary rollers, and also rotate concentrically with the center roller 6. It revolves in the same direction.

As the output board 1 rotates with this reduced rotational speed,
3 transmits the rotation to the coaxial output rotating shaft 15.

In the present invention, the pressure ring 20 is urged toward the output side in the axial direction by the pressure spring 21 within the housing 2, and the pressure ring 20 and the fixed ring 19 are Three driven rollers 7 with vertical component
The biasing force of the pressure spring 21 can be easily and arbitrarily changed by selecting the pressure spring 21.
1 does not need to be strong; it may be sufficient to maintain contact between the driven roller 7 and the center roller 6.

In the present invention, when the driven roller 7 is fitted onto the rotary support shaft 8, an eccentric bush 9 which is characteristically rotatable is interposed therebetween. That is, as shown in FIGS. 2 and 3 (a) and (b), each of the three eccentric bushes 9 is configured to have an eccentric amount 9a. therefore,
As shown in Figure 3 (a), the rotation support shaft 8 is
Even if the pitch 8' of is shifted and a gap 9b is created between the center roller 6 and some of the driven rollers 7, as long as the gap 9b is within twice the eccentricity 9a of the eccentric bushing 9, The interval 9b is automatically corrected by the angular displacement of the eccentric bushing 9.
can be packed. In other words, the eccentric bush 9 having an eccentric amount 9a is rotatably inserted into the rotation support shaft 8, and as described above, the driven roller 7 is always fixed to the center roller by the fixing ring 19 and the pressure ring 20. Since it is pressurized in six directions, the eccentric bushing 9 automatically corrects its eccentric portion during the rotation and revolution of the driven roller rough, as shown in FIG. Normal contact between the convex surface 7a and the outer groove 6a of the center roller 6 is maintained.

Furthermore, if the distance between some of the driven rollers 7 and the center roller 6 is negative, and they press each other strongly, and abnormal wear is expected at the contact area, the eccentric bushing 9 will It performs angular displacement, and in the end,
The uneven contact pressure between the three driven rollers 7 and the center roller 6 is automatically corrected by the angular displacement of the eccentric bushing 9.
Even contact will be achieved.

The arc-shaped concave groove 6a of the center roller 6 in the illustrated embodiment is not limited to the arc shape, but may be in the shape of a square or the same cylindrical shape, and together with the shape of the outer peripheral convex surface 7a of the driven roller luff, uniform continuous contact with each other during rotation is ensured. It doesn't have to be a hindrance. Further, the needle bearing 10 of the driven roller rough may be a ball bearing or any other bearing.

Although the above embodiments of the present invention have been explained exclusively as reduction gears, when a motor is attached to the output rotation shaft 15 side in the above embodiments and rotation is input to the output rotation shaft 15, the input Speed-up rotation is obtained on the rotating shaft 4, and it is clear that the present invention also operates as a speed increaser. It can also be suitably used as a mechanical speed increaser or reducer for equipment that requires low rotational unevenness, low vibration, or low noise.

〔Effect of the invention〕

As is clear from the above description, in the speed increase/reduction gear of the present invention, a rotatable eccentric bushing is interposed between the driven roller and the rotation support shaft, and the pressing force of the driven roller to the center roller is appropriately applied. Therefore, there is a defect in the accuracy of the rotation support shaft pitch circle, and there is also a misalignment between the center of the rotation support shaft pitch circle and the axis of the output board and therefore the output rotation shaft, and the contact pressure between the driven roller and the center roller is Even if the output is not aligned, it is automatically corrected by the angular displacement of the eccentric bushing, and no abnormal vibration or creaking of the output board or output rotation shaft occurs. Therefore, according to the present invention, the driven roller and the center roller can be brought into contact with each other stably and with high precision, and the motorized cloud has good rotational efficiency, long life, and is low-cost and does not require a large number of gears. A speed increase/decelerator suitable for use in tables and other general equipment requiring low rotational unevenness can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a side sectional view of the speed increaser/deceleration gear of the present invention, Fig. 2 is a sectional view taken along the line nn in Fig. 1, and Fig. 3 (a) shows the case where the pitch circle of the rotation support shaft is shifted. FIG. 3(B) is a partially enlarged sectional view illustrating poor contact between the driven roller and the center roller, and FIG.
Fig. 4 is a perspective view of a conventional electric pan head, Fig. 5 is a partial side sectional view of a conventional electric pan head reducer, and Fig. 6 is an inside of the reducer in Fig. 5. FIG. 3 is a partial cross-sectional view illustrating the function of the outer circumferential ring of FIG. 1...Reducer 2...Housing 3...
・Housing lid 4...Input rotating shaft 6...Center roller 7...Followed roller 8...Rotation support shaft 9...Eccentric bushing 10...Needle bearing 13...Output board 19...・Fixing ring 20...Pressure ring 21...Pressure spring 15...Output rotating shaft 19a...Tapered surface 20a...Tapered surface

Claims (1)

[Claims] A center roller formed coaxially with the input rotation shaft, a driven roller that rotates and revolves around the center roller while contacting the center roller, and an output board formed coaxially with the output rotation shaft and fixing the rotation support shaft of the driven roller. In the planetary roller speed increaser/deceleration gear, the driven roller is rotatably fitted to a rotation support shaft to which an eccentric bush is fitted, via a bearing, and the driven roller and the axial input side and A driven roller pressing means includes a pressure ring and a fixed ring having tapered surfaces on the inner periphery that face each other in contact from the axial output side, and a pressure member that presses the pressure ring in the axial direction from the input side. An increase/decrease gear.