JP2006121771A - Non-backlash motor with electromagnetic brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-backlash motor incorporating an electromagnetic off-brake in which such a state as a clearance is eliminated in the thrust direction of the rotary shaft of a rotor can be sustained continuously while exhibiting excellent assembling performance. <P>SOLUTION: A ball bearing housing 2a is provided on the inner circumference of a yoke 2, two ball bearings 3a and 3b are provided on the outer circumference 5a at the shaft coupling portion of a rotary plate 5, the yoke 2 and the rotary plate 5 are constituted integrally through the ball bearings 3a and 3b, and an electromagnetic off-brake fixed with the rotary plate 5 such that it cannot be displaced in the thrust direction is incorporated in the non-backlash motor with an electromagnetic brake. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a non-backlash motor having a built-in non-excitation operation type electromagnetic brake that is braked by the force of a brake spring when a coil is not excited.

  Conventionally, a motor with an electromagnetic brake is used as a motor used in a high-tact device such as a component mounting machine, and in particular, a non-excitation operation type electromagnetic brake having a configuration in which a yoke and a rotating plate are separated separately is generally used. It is used.

  In the case of a servo motor having an optical encoder, it is generally practiced that the electromagnetic brake is built in the motor in order to eliminate the influence of the lining wear powder of the electromagnetic brake and reduce the thickness.

  This non-backlash type motor with a built-in electromagnetic brake is fixed by pressing the outer ring of one ball bearing with a shrink fit or the yoke of the brake, and fixing the outer ring of the other ball bearing with an adhesive. It is assembled with no clearance in the direction.

On the other hand, in order to reduce the number of assembly steps to the motor and to keep the thrust gap between the yoke and the rotating plate constant, a non-excitation actuated electromagnetic brake is known in which the field yoke and the rotating plate are integrally formed via a ball bearing. (For example, refer to Patent Document 1).
Japanese Patent Laid-Open No. 2002-5205

  The problem to be solved is to maintain a state where the clearance in the thrust direction of the rotor rotating shaft to which the hub of the electromagnetic brake is fixed is eliminated, but the yoke and the rotating plate are separated from each other. In the non-excitation operation type electromagnetic brake, when the coil of the electromagnetic brake is not excited, the armature presses the rotating plate by the force of the brake spring, and a load is applied in the thrust direction of the rotor rotating shaft. In the motor assembling process, until the clearance in the thrust direction of the rotor rotating shaft to which the hub of the electromagnetic brake is fixed is maintained, the adhesive for fixing the outer ring of the bearing is completely cured to ensure the adhesive strength. (6 hours or more at normal temperature), it is necessary to energize the coil of the electromagnetic brake and keep it in an excited state, and it is not possible to proceed to the next process, increasing the number of assembly steps and making it impossible to shorten the manufacturing lead time. It was.

  In addition, it is necessary to adjust the gap between the field yoke and the armature when incorporating the motor into the motor, and the man-hours for that purpose have increased.

  Furthermore, when it is installed in equipment and operated at high tact time, every time the braking force is activated without exciting the coil, an impulsive thrust force is applied to the ball bearing of the motor, and the adhesive strength of the ball bearing is reduced. This caused peeling, leading to a decrease in the armature's attractive force due to an increase in the thrust gap of the electromagnetic brake, and a signal processing error due to an increase in the gap between the fixed slit plate and the rotary slit plate of the encoder.

The above-mentioned Japanese Patent Application Laid-Open No. 2002-5205 solves these problems. However, with one ball bearing, the internal thrust clearance of the ball bearing cannot be eliminated when the coil is not excited. When the adhesion is lost, a thrust backlash corresponding to the thrust gap inside the ball bearing is generated, and a signal processing error due to an increase in the gap between the light receiving portion of the encoder and the rotary slit plate cannot be prevented.

  The present invention solves the above-described conventional problems, and provides a non-backlash motor having a built-in non-excitation actuated electromagnetic brake that is excellent in assemblability and that can continuously maintain a state in which the clearance in the thrust direction of the rotor rotating shaft is eliminated. The purpose is to provide.

  In order to solve the above problems, the present invention provides a ball bearing housing on the inner periphery of the yoke, two ball bearings on the outer periphery of the shaft coupling portion of the rotating plate, and the yoke and the rotating plate are integrated with the ball bearing. And a non-backlash motor with a built-in non-excitation actuated electromagnetic brake in which the rotating plate is mounted so as not to be displaced in the thrust direction.

  According to the non-backlash motor with an electromagnetic brake of the present invention, since the rotating plate cannot be displaced in the thrust direction, the time required for the adhesive for fixing the outer ring of the bearing to be completely cured when incorporated in the motor, Since it is not necessary to energize the coil and keep it in an excited state, the number of assembly steps can be reduced, and the manufacturing lead time can be shortened.

  In addition, since it is not necessary to adjust the gap between the yoke and the armature, the assemblability can be improved.

  Since the thrust force generated by the brake spring every time the electromagnetic brake is actuated is received by the ball bearing of the electromagnetic brake, the thrust force applied to the ball bearing of the motor is reduced only to the thrust load caused by the external load. Decrease in adhesive strength and adhesion peeling can be suppressed, and reduction in armature attraction due to increase in thrust gap of electromagnetic brake and signal processing error due to increase in gap between fixed slit plate and rotary slit plate of encoder can be prevented.

  Further, even if the adhesion of the motor ball bearing is removed, thrust backlash is not generated, so that it is possible to prevent a decrease in the armature suction force and an encoder signal error due to an increase in the brake gap.

  Accordingly, it is possible to provide a non-backlash motor incorporating a non-excitation operation type electromagnetic brake that can continuously maintain a state in which the clearance in the thrust direction of the rotor rotating shaft is eliminated.

A ball bearing housing is provided on the inner periphery of the yoke, two ball bearings are provided on the outer periphery of the shaft coupling portion of the rotating plate, and the yoke and the rotating plate are integrally formed by the ball bearing, and the rotating plate is disposed in the thrust direction. Non-backlash motor with electromagnetic brake with built-in non-excitation actuated electromagnetic brake

  In FIG. 1, the coil 1 is wound around a yoke 2. A ball bearing housing 2 a is provided on the inner periphery of the yoke 2. The ball bearing 3a and the ball bearing 3b are pressed and fixed in a thrust direction by pressing the outer ring in the ball bearing housing 2a with the outer ring spacer 4a in between, and the inner rings of the ball bearing 3a and the ball bearing 3b are in the middle with the inner ring spacer 4b in the middle. It is attached to the outer periphery 5a of the shaft connecting portion of the rotating plate 5 by pressing it in the thrust direction with the push nut 6, and the yoke 2 and the rotating plate 5 are supported by the two ball bearings 3a and 3b to be integrally connected. It is composed.

On the other hand, the outer ring end surface of the ball bearing 3b is positioned so as to contact the stepped portion 2c of the ball bearing housing 2a, and the inner ring end surface is positioned to contact the stepped portion 5b of the shaft connecting portion. A desired thrust gap can be formed between the yoke 2 and the armature 7 by setting the positions of the step portions 2c and 5b to be predetermined positions.

  Note that the thrust lengths of the outer ring spacer 4a and the inner ring spacer 4b are adjusted in advance so as to apply the fixed position preload to the ball bearings 3a and 3b.

  The fixed slit 8 of the optical encoder is fixed to the bracket 10 via the encoder frame 9, and the rotating slit 11 plate is adjusted to a predetermined thrust gap between the fixed slit 8 and attached to the motor rotating shaft 12 with a screw 11a. It has been.

  In the motor assembly process, first, the rotor rotating shaft 12 is inserted into the shaft coupling portion shaft hole of the rotating plate 5 of the electromagnetic brake. The rotor rotating shaft 12 is press-fitted into the inner ring of the ball bearing 13 in which the outer ring is press-fitted into the housing of the bracket 10.

  The electromagnetic brake yoke 2 is fixed to the bracket 10 with screws 10a, and the rotary plate 5 is fixed to the rotor rotating shaft 12 with screws 5c. At this time, the coil 1 of the electromagnetic brake is in an unexcited state, and the armature 7 presses the rotating plate 5 in the axial direction by the force of a plurality of brake springs 14, but the yoke 2 and the rotating plate 5 are integrated with the ball bearings 3a and 3b. Since the rotary plate 5 is mounted so as not to be displaceable in the thrust direction, the thrust force generated by the brake spring 14 is received by the yoke 2 via the ball bearings 3a and 3b. No thrust force is applied. The thrust gap between the yoke 2 and the rotating plate 5 can also maintain the initial set value.

  Next, the stator 15 is inserted, the inner ring of the ball bearing 16 is press-fitted and fixed to the rotor rotating shaft 12, the fixing adhesive is applied to the outer ring portion of the ball bearing 16, and the bracket 17 is attached. Thus, even if the coil 1 of the electromagnetic brake is in a non-excited state, the thrust force due to the force of the brake spring 14 is not applied to the rotor rotating shaft 12, so the hardening of the adhesive applied for fixing the outer ring of the ball bearing 16 is awaited. Therefore, it is possible to proceed to the next encoder assembling process, and to reduce the assembly man-hours and the manufacturing lead time.

  Further, since the thrust force generated by the brake spring 14 generated every time the electromagnetic brake is operated is received by the ball bearings 3a and 3b of the electromagnetic brake, the thrust force applied to the ball bearings 13 and 16 of the motor is reduced only to the thrust load due to the external load. Is done. For this reason, a decrease in adhesion strength of the ball bearing 16 of the motor and adhesion peeling can be suppressed, a decrease in the attractive force of the armature 7 due to an increase in the thrust gap of the electromagnetic brake, and an increase in the gap between the fixed slit plate 8 and the rotary slit plate 11 of the encoder. Signal processing errors can be prevented.

  Furthermore, even if the adhesive of the ball bearing 16 of the rotor rotating shaft 12 is lowered and peeled, the yoke and the rotating plate 5 are integrally formed by two ball bearings 3a and 3b, and the rotating plate 5 is made in the thrust direction. Therefore, it is possible to prevent a reduction in the attractive force of the armature 7 due to an increase in the thrust gap of the electromagnetic brake and a signal processing error due to an increase in the gap between the fixed slit plate 8 and the rotary slit plate 11 of the encoder. .

  The non-backlash motor with an electromagnetic brake according to the present invention is most suitable for high-acting equipment, and is useful for applications that dislike changes in the thrust axis clearance in the thrust direction.

Sectional drawing of the non-backlash motor with an electromagnetic brake in Example 1 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coil 2 Yoke 3a, 3b Ball bearing 4a Outer ring spacer 4b Inner ring spacer 5 Rotating plate 6 Push nut 7 Armature 8 Fixed slit 11 Rotating slit 12 Rotor rotating shaft 14 Brake spring

Claims (1)

A ball bearing housing is provided on the inner periphery of the yoke, two ball bearings are provided on the outer periphery of the shaft coupling portion of the rotary plate, and the yoke and the rotary plate are integrally formed via the ball bearing, and the rotary plate Non-backlash motor with electromagnetic brake, which has a built-in non-excitation electromagnetic brake that is mounted so that it cannot be displaced in the thrust direction.

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