JP2576610B2 - Coupling structure between motor and encoder - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a coupling structure for connecting a motor and a rotary encoder for detecting a rotation angle and the like of the motor.

[Related Art] In recent machines operated by a motor, accurate positioning is often an important control item. Therefore, a rotary encoder is connected to the rotor of the motor, and the relative or absolute rotation angle of the rotor is detected by the encoder.

If the motor and the encoder are completely rigidly connected with bolts or the like, the following problem occurs. One is that since the encoder is a precision machine, if the displacement or vibration of the rotor during the operation of the motor is transmitted to the encoder, a malfunction or failure may occur. Second, it is difficult to assemble the motor and the encoder so that the rotation centers of the motor and the encoder are completely coincident. If a slight misalignment remains during the assembling, an excessive load is applied to the motor or the encoder. One of them could be damaging. As a third problem, when the motor repeatedly starts and stops suddenly, there is a possibility that the joint portion may be broken due to fatigue in a rigid connection such as a bolt.

In order to avoid such a problem, various proposals have conventionally been made regarding a coupling structure between a motor and an encoder. Japanese Utility Model Application Laid-Open No. 56-166517 discloses a structure using a disc-shaped elastic body in order to allow a slight inclination between the encoder body and the motor mounting board. JP-A-59-19809 discloses a coupling structure in which a motor rotation shaft and an encoder rotation shaft are connected by a taper, and a motor body and an encoder body are connected by a ring-shaped leaf spring. I have. Furthermore, Akira Kai
Japanese Patent Application Laid-Open No. 61-157820 discloses an example in which a motor body and an encoder body are connected by a corrugated thin plate spring.

[Problems to be Solved by the Invention] For example, when the motor and the encoder are used in a poor environment with a lot of dust and the like, a casing in which both bodies are integrally sealed to prevent intrusion of dust into the inside. There is a need. In addition, there is a case where it is desired to make a rigid connection between the main body of the motor and the encoder due to a problem of attachment to the device. In any of the above-mentioned conventional techniques, as described above, the coupling between the motor main body and the encoder main body is made to be a soft coupling by a leaf spring or the like, and thus is not suitable as a coupling structure in such a case. .

[Means for Solving the Problems] The present invention combines the rotating shafts of a motor and an encoder with each other, and also absorbs positional displacement and run-out of the two, so that a large number of rapid start / stop operations can be performed. This realizes a coupling mechanism that can withstand the above. In order to solve such a problem, the present invention provides that one shaft is hollow,
Regarding the coupling structure that connects the rotary shaft of the motor and the rotary shaft of the encoder in which the other shaft is inserted into the hollow shaft, one or more protrusions are provided on each of both shafts, and the protrusions are fully protruded. The end faces of the portions are aligned on a plane perpendicular to the rotation axes of both shafts, and are fixed by a single annular leaf spring.

[Operation] First, the other shaft is inserted into the hollow shaft so that the rotation axes of both shafts coincide with each other. Then, the end surfaces of the protruding portions provided on each of the shafts are aligned on a plane perpendicular to both the rotation axes, and they are fixed by a single annular leaf spring.

For example, when the interpolation shaft (when the shaft of the motor is inserted) rotates, the rotation is transmitted to the other hollow shaft (encoder shaft) by the annular leaf spring without delay. Therefore, changes in the rotation angle and rotation speed of the motor can be immediately detected by the encoder. On the other hand, if the motor shaft generates an axial vibration while rotating, the vibration is absorbed by the annular leaf spring and is not transmitted to the encoder shaft. As a result, the encoder can accurately detect the rotation, and there is no problem of malfunction due to vibration.

Embodiment An embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the shaft 12 protrudes from the motor 10 main body,
The rotary encoder 14 is attached so as to cover the periphery of the protruding motor shaft 12. A step 18 is provided around the case 16 of the encoder 14, and the step 18 is fitted to the outer peripheral edge 22 of the case 20 of the motor 10.
6, 20 are attached with bolts (not shown). An O-ring 24 is inserted in the fitting step to prevent water, dust, and the like from entering the motor 10 and the encoder 14 from the joint between the cases 16 and 20.

The shaft 30 of the encoder 14 is hollow, and is fitted to the outside of the protruding portion of the motor shaft 12 from the main body of the motor 10. On the surface of the motor shaft 12 on the side facing the encoder shaft 30, two annular grooves are provided, each of which has a 0 ring.
32 and 34 are fitted to keep the shafts 12 and 30 airtight. Although the motor shaft 12 and the encoder shaft 30 are both hollow in this embodiment, the encoder shaft 30
Corresponds to the hollow shaft referred to in the present invention, and the motor shaft 12 corresponds to the interpolation shaft. Therefore, the motor shaft 12 may be a solid shaft.

Two axially protruding projections 36 are provided 180 ° apart from each other at the right end of the motor shaft 12 in FIG. 1, and a bolt hole 38 is provided at the end face of the tip. Two inner diameter projecting protrusions 40 are provided at the same end of the encoder shaft 30 at a distance of 180 ° from each other, and bolt holes 42 are similarly provided on the right end surface thereof.

Next, a method of connecting the motor and encoder shafts 12, 30 will be described. After the two shafts 12 and 30 are inserted through the O-rings 32 and 34, the two protrusions of the encoder shaft 30 are formed.
The angle is adjusted so that the projection 40 and the two projections 36 of the motor shaft 12 are arranged at an angle of 90 ° to each other (FIG. 2), and the end faces of both projections 36 and 40 are on the same plane. Adjust the axial position. In this state, an annular leaf spring 44 is applied to the end faces of the four projections 36 and 40, and the leaf spring 44 is fixed to both shafts 12 and 30 with four bolts. At this time, since all bolts can be attached from the same direction (the right side in FIG. 1), attachment, maintenance and the like are easy.

Thus, the motor shaft 12 is connected to the encoder shaft 30 via the annular leaf spring 44, and the motor shaft 12
Is transmitted to the encoder shaft 30 without delay.
A rotor 46 is attached to the encoder shaft 30, and the absolute or relative rotation angle of the motor 10 is electro-optically detected by the rotor 46 and the stator 48 attached to the case 16 of the encoder 14. On the other hand, even if the motor shaft 12 vibrates in the axial direction (the left-right direction in FIG. 1), the vibration is absorbed by the leaf spring 44 and is not directly transmitted to the encoder shaft 30. And the durability is improved.

[Effect of the Invention] In the coupling structure according to the present invention, the coupling between the motor shaft and the encoder shaft is performed by an annular leaf spring. Therefore, the main bodies of the motor and the encoder can be rigidly connected to each other, and the dustproof structure and the like can be easily formed. Also,
While the annular leaf spring transmits the rotation of the motor accurately, it absorbs the vibration in the axial direction and does not transmit it to the encoder, so that it is possible to detect the rotation accurately and to prevent problems due to the vibration of the motor and the encoder. . Further, in the present invention, since the annular leaf spring is attached to the end face where the protruding portions of both shafts are aligned, the attachment of the annular leaf spring by a bolt or the like can be performed from only one direction, which facilitates the attachment and maintenance. It also has the effect.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a motor / encoder coupling portion, and FIG. 2 is a front view of the coupling portion. 10 ... Motor, 12 ... Motor shaft, 14 ... Encoder, 30 ... Encoder shaft, 36, 40 ... Protrusion, 44 ... Annular leaf spring

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Kazunari Hashimoto 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-59-19809 (JP, A) JP-A-62- 172263 (JP, A) Fully open 60-74013 (JP, U)

Claims (1)

(57) [Claims] 1. A cup for connecting a rotary shaft of a motor having one hollow shaft and the other shaft inserted into the hollow shaft and a rotary shaft of an encoder for detecting the rotation of the motor. A ring structure, wherein at least one protrusion is provided on each of both shafts, and the end faces of all the protrusions are aligned with a plane perpendicular to the rotation axes of both shafts.
A coupling structure between a motor and an encoder, wherein the coupling structure is fixed by two annular leaf springs.