JPH0722125U - Rotating device - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a means capable of easily setting the torque required to rotate the rotary shaft of a manual rotary device such as an encoder. In a rotating device in which a rotary shaft (1) is rotatably supported by a radial bearing (3) provided in a housing (2), two retainer rings (4,5) are provided on the rotary shaft so as to sandwich the bearing. Attach. Then, a disc spring (9) is arranged in the gap between the one retainer ring (5) and the bearing to apply a pressing force to the rotating shaft, and the other retainer ring (4) slides on the end surface of the bearing. The feature is that they are brought into contact with each other as much as possible. By adjusting the pressing force of the disc spring to adjust the friction generated between the retainer ring (4) and the bearing, the starting torque and the rotating torque of the rotary shaft can be easily set.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotary device such as an encoder or a potentiometer, and more particularly to a torque setting means for setting a starting torque and a rotary torque of a rotary shaft. Here, the starting torque means a torque value required to rotate the rotating shaft from a stationary state, and the rotating torque means a torque value necessary to rotate the rotating shaft at a constant speed.

[0002]

[Prior art]

 FIG. 3 is a diagram showing the bearing surroundings of a conventional encoder used for inputting a numerical value or detecting an angle of a manual pulse generator. As shown in the figure, the rotary shaft 1 of the encoder is passed through a radial bearing 3 provided in a housing 2 and is thereby supported in the radial direction. In addition, two retainer rings 4 and 5 are attached to the rotary shaft 1 to support the rotary shaft 1 in the axial direction.

The illustrated radial bearing 3 is a slide bearing, and a lubricant is filled between the bearing surface and the outer peripheral surface of the rotary shaft 1. Conventionally, when the starting torque and the rotating torque of the rotary shaft 1 are set, the viscosity of the lubricant is changed.

[0004]

[Problems to be solved by the device]

 However, the conventional means for setting the torque of the rotating shaft by the lubricant has a problem that it is extremely difficult to select the viscosity of the lubricant. That is, for example, in order to give the user a certain amount of weight when the rotary shaft is being rotated manually, increasing the viscosity of the lubricant causes the starting torque to be much larger than the rotation torque due to the characteristics of the lubricant. , It may be difficult to start the rotating shaft. Further, in the case of a lubricant having a high viscosity, when the rotary shaft is rotated several times and then allowed to stand, a phenomenon in which the rotary shaft reversely rotates, that is, a so-called return phenomenon may occur. This phenomenon becomes noticeable when the viscosity of the lubricant becomes higher in a low temperature environment.

On the contrary, if the viscosity of the lubricant is reduced to facilitate the starting of the rotating shaft, the rotating torque becomes small, and the operating feeling of the rotating shaft at the time of rotating operation may become too light. Also, since the viscosity of the lubricant becomes low in a high temperature environment, if the knob attached to the rotating shaft or the center of gravity of other parts is not at the center of rotation, the rotating shaft may rotate naturally when the hand is released. There is also this.

Therefore, an object of the present invention is to provide a rotating device such as an encoder provided with a torque setting means other than that using a lubricant.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention provides a rotating device in which a rotary shaft is rotatably supported by a radial bearing provided in a housing, and a spring means for pressing the rotary shaft in one direction parallel to its axis. Provided to prevent the rotary shaft from moving in the pressing direction by slidably contacting a part of the radial bearing or a part of the housing around the radial bearing when the rotary shaft is pressed by the spring means. The feature is that the contact surface is provided on the rotating shaft.

In particular, the spring means includes a pressed surface provided on the rotating shaft so as to face the contact surface so as to sandwich the radial bearing between the contact surface and the contact surface, and to apply a pressing force to the pressed surface. It is preferably composed of a disc spring fitted to the rotary shaft between the pressing surface and the radial bearing.

[0009]

[Action]

 In the above construction, the pressing force of the spring means determines the magnitude of friction at the contact portion between the rotary shaft and the radial bearing or the housing, which determines the torque required to rotate the rotary shaft. Therefore, the starting torque and the rotational torque can be set to desired magnitudes by adjusting the pressing force of the spring means.

[0010]

【Example】

 Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to FIGS. 1 and 2. In the figure, the same reference numerals are used for the same or corresponding portions as those of the conventional configuration described with reference to FIG. And

FIG. 1 shows around a bearing of a manual rotary device, for example, an encoder or a potentiometer to which the present invention is applied, and FIG. 2 is an exploded perspective view thereof. A radial slide bearing 3 is provided in a housing 2 of the illustrated rotating device. The bearing 3 is composed of a cylindrical body made of a suitable material such as metal, and is integrally attached to the housing 2. Of course, depending on the material of the housing 2, it is possible to form a through hole having an inner peripheral surface as a bearing surface in the housing 2 and use the housing 2 itself as the bearing 3.

The rotary shaft 1 is rotatably inserted in the bearing 3 and is supported in the radial direction. The outer diameter of the journal portion of the rotating shaft 1 is made slightly smaller than the inner diameter of the bearing 3 within a range where radial play is not generated, and a lubricant is filled between the two.

Further, on the outer peripheral surface of the rotary shaft 1, two peripheral grooves 6 and 7 are formed at predetermined intervals in the axial direction. The interval L1 between the circumferential grooves 6 and 7 is set longer than the length L2 of the bearing 3. C-shaped retainer rings 4 and 5 are snap-fitted into the respective circumferential grooves 6 and 7. One retainer ring 4 slidably contacts one end surface 3a of the bearing 3 through a washer 8 preferably made of synthetic resin. The other retainer ring 5 is arranged at a constant distance from the other end surface 3b of the bearing 3.

A disc spring 9 is fitted on the rotary shaft 1 between the retainer ring 5 and the end surface 3b of the bearing 3, and the end surface 3b of the bearing 3 and the surface of the retainer ring 5 facing the end surface 3b. A pressing force is applied to the pressing surface in opposite directions. As a result, the other retainer ring 4 is pressed against the end surface 3a of the bearing 3 and is prevented from moving in the A direction in FIG. A washer 10 made of synthetic resin or the like is interposed between the disc spring 9 and the retainer ring 5 and slidably contacts the retainer ring 5.

In such a configuration, when the rotary shaft 1 is rotated, the rotary shaft 1 and the retainer rings 4, 5 rotate with respect to the housing 2, the bearing 3, the disc spring 9, and the washers 8, 10. As a result, friction is generated at each of the contact portions between each pair of washers 8 and 10 and the retainer rings 4 and 5. The amount of friction generated in this portion is determined by the pressing force of the disc spring 9, and the torque required to rotate the rotating shaft 1 is also determined by the amount of this friction and the viscosity of the lubricant. Therefore, the torque of the rotary shaft 1 can be set to a desired magnitude by adjusting the pressing force by the disc spring 9 and changing the magnitude of friction without changing the viscosity of the lubricant as in the conventional case. It will be possible.

The friction generated at the contact portion between the washers 8 and 10 and the retainer rings 4 and 5 includes static friction generated at the time of starting and dynamic friction generated during rotation. Since static friction is greater than dynamic friction, starting torque is greater than rotational torque. Therefore, the torque can be set so that a heavy feeling is given to the user when the rotating shaft 1 is started to be turned, and a relatively light feeling is given after the rotating shaft 1 is started to rotate once.

Further, the difference in magnitude between the starting torque and the rotating torque is small as compared with the case where the torque is set only by the lubricant, and therefore even if the starting torque is made small, the rotating torque becomes excessively small. It won't happen.

Since the rotary shaft 1 is pushed in the A direction and the retainer ring 4 is slidably pressed against the bearing 3, the rotary shaft 1 can be rotated without backlash in the thrust direction. it can.

In the above embodiment, the disc spring 9 is used as the spring means for applying the pressing force to the rotary shaft 1, but the spring means may be another spring such as a coil spring. Further, the installation position is not limited to the illustrated position, and for example, a pressing force may be applied to one end surface of the rotary shaft 1. In such a case, the contact surface where friction that affects the torque occurs is only on the retainer ring 4 side.

Further, the bearing 3 in the above embodiment is a radial slide bearing, but it may be a bearing of another type such as a radial roller bearing. However, depending on the model, the part in contact with the retainer ring may be part of the housing 2 around the bearing.

[0021]

[Effect of device]

 As described above, according to the present invention, by adjusting the pressing force of the spring means, it is possible to easily set the starting torque and the rotating torque of the rotary shaft to desired magnitudes.

Further, since the set value hardly changes depending on the change of the environmental temperature, there is a problem that the rotating shaft may rotate around due to the shift of the center of gravity of the knob at a high temperature, or the returning phenomenon may occur at a low temperature. To be prevented. This effect is particularly effective for a rotary device that needs to maintain the stationary position of the rotary shaft, for example, an encoder for inputting numerical values of a manual pulse generator.

Further, since the rotating shaft is pressed in one direction by the spring means and the pressure is supported by the contact surface provided on the rotating shaft, play in the thrust direction is prevented, and when the rotating shaft is manually rotated. There is also an effect that the usability of is further improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view taken along the axial direction showing a bearing of a rotating device according to the present invention.

FIG. 2 is an exploded perspective view around a bearing of the rotating device shown in FIG.

FIG. 3 is a sectional view taken along the axial direction showing a bearing of a conventional rotating device (encoder).

[Explanation of symbols]

1 ... Rotary shaft, 2 ... Housing, 3 ... Radial bearing, 4,
5 ... Retainer ring, 6, 7 ... Circumferential groove, 8, 10 ... Washer, 9 ... Disc spring (spring means). Attorney Attorney Hasegawa
Yoshiki

Claims (2)

[Scope of utility model registration request] 1. A rotating device in which a rotating shaft is rotatably supported by a radial bearing provided in a housing, wherein a spring means for pressing the rotating shaft in one direction parallel to its axis, and the rotating shaft is To prevent the rotary shaft from moving in the pressing direction by slidably contacting a part of the radial bearing or a part of the housing around the radial bearing when pressed by spring means, A rotating device, comprising: a contact surface provided on the rotating shaft. 2. The pressing means is provided on the rotating shaft so as to face the contact surface so as to sandwich the radial bearing between the spring means and the contact surface, and a pressing force is applied to the pressed surface. 2. The rotating device according to claim 1, further comprising a disc spring fitted to the rotary shaft between the pressed surface and the radial bearing so as to act.