JP2025005718A - Motor with built-in brake - Google Patents

Abstract

A compact motor with a built-in brake that can accommodate more windings is provided.
[Solution] A motor with a built-in brake 1 has an electromagnetic brake device 3. The electromagnetic brake device 3 has a rotating shaft portion 10, a brake mechanism 20, and a bearing 5 that rotatably supports the brake mechanism 20 with respect to the rotating shaft portion 10. The brake mechanism 20 has a winding 21 and a yoke 30. The yoke 30 has an accommodating portion 37 and a bearing fixing portion 36 to which an outer ring 52 of the bearing 5 is fixed. When viewed from the radial direction of the rotation axis Ax, at least a portion of the accommodating portion 37 overlaps with the bearing fixing portion 36.
[Selected figure] Figure 2

Description

The present invention relates to a motor with a built-in brake.

Patent document 1 discloses a motor with a built-in brake in which the rear end of the motor shaft is supported by a motor end plate via a bearing.

JP 2002-005205 A

In the motor with an internal brake described in Patent Document 1, a dead space occurs between the motor end plate and the rear end of the motor, which increases the axial length of the entire motor with an internal brake.
Therefore, an object of the present disclosure is to provide a motor with a built-in brake that is small and can accommodate more windings.

A motor with a built-in brake according to one aspect of the present invention comprises:
A motor with a built-in brake, the motor having an electromagnetic brake device that applies a braking force to the motor when the motor is not energized,
The electromagnetic brake device is
A rotation shaft portion extending in a rotation axis direction;
a brake mechanism that applies a braking force to the rotating shaft portion;
a bearing that rotatably supports the brake mechanism with respect to the rotating shaft portion,
The winding and
a yoke for receiving the winding;
the yoke has an accommodating portion that accommodates the winding and a bearing fixing portion to which an outer ring of the bearing is fixed,
When viewed in a radial direction of the rotation axis, at least a portion of the housing portion overlaps with the bearing fixing portion.

The present disclosure provides a compact motor with built-in brake that can accommodate more windings.

FIG. 1 is a cross-sectional view of a motor with an integrated brake according to the present disclosure. FIG. 2 is an enlarged view of a portion of FIG. 1 showing the brake mechanism.

The following describes an embodiment of the present invention with reference to the drawings. For the sake of convenience, the description of components having the same reference numbers as components already described in the description of the embodiment will be omitted.

Figure 1 is a cross-sectional view of a motor with an internal brake 1 according to the present disclosure. As shown in Figure 1, the motor with an internal brake 1 has a motor 2, an electromagnetic brake device 3, and a case 4 that covers the motor 2 and the electromagnetic brake device 3. The motor with an internal brake 1 according to the present disclosure is a motor with an externally actuated electromagnetic brake in which a braking force acts on the motor 2 when not energized.

The electromagnetic brake device 3 has a rotating shaft portion 10 extending in the direction of the rotation axis Ax, a brake mechanism 20 that applies a braking force to the rotating shaft portion 10, and a bearing 5 that supports the brake mechanism 20 so that it can rotate with respect to the rotating shaft portion 10. In the following explanation, the left side of FIG. 1 in the direction of the rotation axis Ax may be referred to as the front F, and the right side of FIG. 1 in the direction of the rotation axis Ax may be referred to as the rear R.

In FIG. 1, the electromagnetic brake device 3 is provided behind the motor 2. The rotating shaft portion 10 is connected to the output shaft 2a of the motor 2. The rotating shaft portion 10 rotates around the rotation axis Ax together with the motor 2. The rotating shaft portion 10 may be integral with the output shaft 2a of the motor 2, or may be a separate member from the output shaft 2a of the motor 2. The rotating shaft portion 10 may also be connected to the output shaft 2a of the motor 2 by a power transmission member such as a gear.

The brake mechanism 20 includes a winding 21 , a yoke 30 that houses the winding 21 , and a spring 22 .
The winding 21 is disposed within the yoke 30 and is a metal wire, such as a copper wire, wound to form a coil. The winding 21 is wound to form a coil having a substantially cylindrical shape as a whole.

The yoke 30 is a metal member having an accommodation portion 37 inside which the winding 21 is accommodated. The yoke 30 is a cylindrical member with a bottom. The yoke 30 integrally has an inner wall portion 31 that covers the inner circumference of the cylindrical winding 21, an outer wall portion 32 that covers the outer circumference of the cylindrical winding 21, and an end wall portion 33 that covers the end of the cylindrical winding 21 on the opposite side of the rotation axis Ax to the motor 2.

The rotating shaft 10 passes through a through hole 34 on the inner periphery of the inner wall 31. The rotating shaft 10 is rotatably supported relative to the yoke 30 via a bearing 5 provided in the yoke 30.

The internal space formed by the inner peripheral wall portion 31, the outer peripheral wall portion 32, and the end wall portion 33 is the accommodation portion 37. The accommodation portion 37 opens forward (toward the motor 2) in the direction of the rotation axis Ax. When current is applied to the winding 21, the yoke 30 forms a magnetic circuit of magnetic lines of force generated in the winding 21. The yoke 30 increases the magnetic flux density of the magnetic force, thereby increasing the magnetic force.

Figure 2 is a partially enlarged view of Figure 1 showing the brake mechanism 20. As shown in Figure 2, the brake mechanism 20 further has a friction member 23, an outer plate 24, an inner plate 25, and a guide pin 26. The outer plate 24, the friction member 23, and the inner plate 25 are arranged in this order from front to rear in the direction of the rotation axis Ax.

The guide pin 26 has a pin 26a extending in the direction of the rotation axis Ax and a sleeve 26b through which the pin 26a is inserted. The head 26c of the guide pin 26 protrudes forward from the front end face of the yoke 30. The rear end of the guide pin 26 located opposite the head 26c is fixed to the yoke 30. The guide pin 26 is fixed to the outer peripheral wall portion 32 located radially outward of the housing portion 37 of the yoke 30. The multiple guide pins 26 are provided along the circumferential direction on the front end face 32a of the outer peripheral wall portion 32 of the yoke 30.

The pin 26a passes through the sleeve 26b. The head 26c of the guide pin 26 is fixed via the sleeve 26b at a position spaced apart from the front end surface 30a of the yoke 30. The guide pin 26 is fixed to the yoke 30 by a fixing means such as adhesive, welding, press-fitting, fitting, or screwing.

The outer plate 24 is a plate-like member extending in a radial direction intersecting the rotation axis Ax. The outer plate 24 is also ring-shaped, and the rotation shaft portion 10 passes through a through hole provided in the radial center of the outer plate 24. The outer plate 24 is fixed by being sandwiched between the head 26c of the guide pin 26 and the sleeve 26b. The outer plate 24 is fixed via the sleeve 26b at a position away from the front end face 30a of the yoke 30. In other words, the outer plate 24 is immovable relative to the yoke 30.

The friction member 23 is a plate-shaped member extending in a radial direction intersecting the rotation axis Ax. The friction member 23 is also ring-shaped, and the rotating shaft portion 10 passes through a through hole provided in the radial center of the friction member 23. The friction member 23 is a member having a surface with a high friction coefficient that generates a friction force between the friction member 23 and the outer plate 24. The friction member 23 can be composed of, for example, a metal main body and a high-friction material made of ceramics or the like attached to the surface of the main body.

The outer peripheral surface of the friction member 23 is located radially inward of the sleeve 26b of the guide pin 26. In the radial direction, the friction member 23 is located between the sleeve 26b and the rotating shaft portion 10.

The inner peripheral surface of the friction member 23 is provided with a fitting groove 23a extending in the direction of the rotation axis Ax. This fitting groove 23a has a shape that corresponds to a fitting portion 27a provided on the outer peripheral surface of a hub member 27 fixed to the rotating shaft portion 10. Therefore, the friction member 23 can move in the direction of the rotation axis Ax relative to the rotating shaft portion 10, but cannot rotate around the rotation axis Ax. In other words, the friction member 23 rotates in conjunction with the rotation of the rotating shaft portion 10.

The inner plate 25 is a plate-like member extending in a radial direction intersecting the rotation axis Ax. The inner plate 25 is also ring-shaped, and the rotation shaft 10 passes through the inner peripheral hole of the inner plate 25. The outer peripheral portion of the inner plate 25 is provided with recesses having a shape corresponding to the sleeves 26b of the guide pins 26. In other words, the inner plate 25 is prevented from rotating around the rotation axis Ax by the sleeves 26b. For this reason, like the friction member 23, the inner plate 25 is movable in the direction of the rotation axis Ax, but cannot rotate around the rotation axis Ax.

Returning to FIG. 1, the spring 22 is housed in a spring housing 35 that opens to the front end face of the yoke 30. The spring 22 is, for example, a coil spring. The spring 22 is housed in the spring housing 35 in a compressed state. The spring 22 exerts an elastic restoring force on the inner plate 25, pressing the inner plate 25 against the friction member 23.

2 , the bearing 5 supports the yoke 30 of the brake mechanism 20 rotatably around the rotation axis Ax with respect to the rotating shaft portion 10. The bearing 5 has an inner ring 51, an outer ring 52, and rolling elements 53. The inner ring 51 is fixed to the rotating shaft portion 10. The outer ring 52 is fixed to the yoke 30. The yoke 30 has a bearing fixing portion 36 to which the outer ring 52 of the bearing 5 is fixed. In the illustrated example, the bearing fixing portion 36 is provided at the rear end portion of the inner circumferential wall portion 31 of the yoke 30.
The motor-side bearing, which is located on the front side in the direction of the rotation axis Ax, supports the output shaft 2 a of the motor 2 rotatably relative to the case 4 .

In the normal state of the motor 2 operating, the motor 1 with built-in brake also supplies power to the windings 21. When current is applied to the windings 21, electromagnetic force is generated by the windings 21. This electromagnetic force attracts the inner plate 25 to the yoke 30 against the elastic restoring force of the spring 22. In this state, gaps are generated between the inner plate 25 and the friction member 23, and between the friction member 23 and the outer plate 24, and no frictional force is generated between the respective members. In other words, in the normal state of the motor 1 with built-in brake, no braking force is generated by the brake mechanism 20.

When the motor 2 is de-energized, such as when the motor 2 is shut off, no electromagnetic force acts on the windings 21. As a result, the inner plate 25 presses the friction member 23 against the outer plate 24 due to the elastic restoring force of the spring 22. As a result, frictional forces are generated between the inner plate 25 and the friction member 23, and between the friction member 23 and the outer plate 24. In other words, in the de-energized state, a braking force is generated by the brake mechanism 20.

In the brake-embedded motor 1 of the present disclosure, as shown in FIG. 2, the accommodation section 37 is a space having a substantially cylindrical main body S and an extension T that protrudes rearward from the outer periphery of the main body S. When viewed from the radial direction of the rotation axis Ax (the direction of arrow II in FIG. 2), at least a portion of the extension T, which is part of the accommodation section 37, appears to overlap with the bearing fixing section 36.

The longer the winding 21 accommodated in the accommodation section 37, the more the number of turns of the winding 21 increases, and the winding resistance value rises. This makes it possible to keep the power consumption of the motor 2 low. The motor with built-in brake 1 according to the present disclosure also uses the area radially outside the bearing 5, which was originally dead space, as the accommodation section 37. Therefore, compared to a motor with built-in brake in which the accommodation section does not overlap the bearing fixing section as viewed in the radial direction of the rotation axis Ax, it is possible to accommodate more windings while maintaining the dimension in the direction of the rotation axis Ax, and therefore power consumption can be reduced. Alternatively, the motor with built-in brake 1 according to the present disclosure can reduce the dimension in the direction of the rotation axis Ax while consuming the same amount of power as a motor with built-in brake 1 in which the accommodation section 37 does not overlap the bearing fixing section 36 as viewed in the radial direction of the rotation axis Ax.

Further, according to the motor with built-in brake 1 of the present disclosure,
The yoke 30 integrally includes an outer peripheral wall portion 32 that covers the outer periphery of the winding 21, and an end wall portion 33 that covers the end of the winding 21 on the opposite side of the rotation axis Ax from the motor 2,
An inner surface 33a of the end wall portion 33 is located on the opposite side (rearward) of the motor 2 in the direction of the rotation axis Ax than a surface 52a of the outer ring 52 of the bearing 5 facing the motor 2 .
With this configuration, a part of the outer peripheral region of the housing portion 37 can be configured to protrude rearward in the axial direction, whereby the housing portion 37 can be provided in the radially outer region of the bearing 5 which was originally a dead space.

Further, according to the motor with built-in brake 1 of the present disclosure,
The storage section 37 has an inner storage section 37A and an outer storage section 37B located outside the inner storage section 37A.
The outer accommodating portion 37B is axially longer than the inner accommodating portion 37A.
More specifically, as shown in Fig. 2, the accommodation portion 37 is divided into a cylindrical inner accommodation portion 37A having an axial length L1 and a cylindrical outer accommodation portion 37B having an axial length L2 longer than the axial length L1 and located on the outer peripheral side of the inner accommodation portion 37A. In this case, it can be expressed that the front end face (the end face on the motor 2 side) of the inner accommodation portion 37A and the front end face of the outer accommodation portion 37B are arranged to be flush with each other, and the rear end face of the outer accommodation portion 37B protrudes rearward from the rear end face of the inner accommodation portion 37A. In this way, a stepped surface is generated on the rear end face of the accommodation portion 37, and the accommodation portion 37 can be provided in an area radially outward of the bearing 5 that was originally a dead space.

Further, according to the motor with built-in brake 1 of the present disclosure,
The brake mechanism 20 is fixed to the case 4 that houses the motor 2.
The brake mechanism 20 applies a braking force to a friction member 23 that rotates together with the rotating shaft portion 10 .
In the motor with built-in brake 1 of the present disclosure, the brake mechanism 20 applies a braking force to the rotating shaft portion 10 by applying a frictional force between the brake mechanism 20 and the friction member 23. The motor with built-in brake 1 of the present disclosure can be suitably applied to a motor with built-in brake 1 having such a configuration.

Further, according to the motor with built-in brake 1 of the present disclosure,
The brake mechanism 20 includes a friction member 23, an inner plate 25, an outer plate 24, and a guide pin 26.
The outer plate 24 is fixed by a guide pin 26 at a position spaced apart from the yoke 30 in the direction of the rotation axis Ax.
The inner plate 25 is supported by a guide pin 26 so as to be movable in the direction of the rotation axis Ax but not rotatable.
The friction member 23 is provided between the inner plate 25 and the outer plate 24 in the direction of the rotation axis Ax.
According to this configuration, during braking, the friction member 23 is sandwiched between the inner plate 25 and the outer plate 24. It is easy to apply a large frictional force using both sides of the friction member 23. The motor with an internal brake 1 of the present disclosure can be suitably applied to a motor with an internal brake 1 having such a configuration.

Although the embodiment of the present disclosure has been described above, it goes without saying that the technical scope of the present disclosure should not be interpreted as being limited by the description of the present embodiment. The present embodiment is merely an example, and it will be understood by those skilled in the art that various modifications of the embodiment are possible within the scope of the invention described in the claims. The technical scope of the present disclosure should be determined based on the scope of the invention described in the claims and its equivalents.

In the above description, an example was described in which the spring housing 35 was provided on the inner peripheral wall 31 of the yoke 30, but the spring housing 35 may also be provided on the outer peripheral wall 32.

In the above description, the friction member 23 is described as a member having a high friction material, but the present disclosure is not limited to this. The friction member 23 may not have a high friction material, and a high friction material may be attached to the portion of the outer plate 24 or the inner plate 25 that comes into contact with the friction member 23. It is sufficient that the friction member 23 is configured to come into contact with at least one of the outer plate 24 and the inner plate 25 to generate a frictional force.

Reference Signs List 1 Motor with built-in brake 2 Motor 2a Output shaft 3 Electromagnetic brake device 4 Case 5 Bearing 10 Rotating shaft portion 20 Brake mechanism 21 Winding 22 Spring 23 Friction member 23a Fitting groove 24 Outer plate 25 Inner plate 26 Guide pin 26a Pin 26b Sleeve 26c Head 27 Hub member 30 Yoke 30a Front end surface of yoke 31 Inner peripheral wall portion 32 Outer peripheral wall portion 32a Front end surface of outer peripheral wall portion 33 End wall portion 33a Inner surface of end wall portion 34 Through hole 35 Spring accommodating portion 36 Bearing fixing portion 37 Accommodating portion 37A Inner accommodating portion 37B Outer accommodating portion 51 Inner ring 52 Outer ring 53 Rolling element 55 Motor side bearing Ax Rotation axis S Main body portion T Extension portion

Claims (5)

A motor with a built-in brake, the motor having an electromagnetic brake device that applies a braking force to the motor when the motor is not energized,
The electromagnetic brake device is
A rotation shaft portion extending in a rotation axis direction;
a brake mechanism that applies a braking force to the rotating shaft portion;
a bearing that rotatably supports the brake mechanism with respect to the rotating shaft portion,
The winding and
a yoke for receiving the winding;
the yoke has an accommodating portion that accommodates the winding and a bearing fixing portion to which an outer ring of the bearing is fixed,
A motor with an internal brake, wherein at least a portion of the accommodation portion overlaps with the bearing fixing portion when viewed in a radial direction of the rotation axis. the yoke integrally includes an outer wall portion that covers an outer periphery of the winding, and an end wall portion that covers an end of the winding on the opposite side of the rotation axis of the motor,
2. The motor with an internal brake according to claim 1, wherein the inner surface of the end wall portion is located on the opposite side to the motor in the direction of the rotation axis than a motor-side surface of the outer ring of the bearing. The storage portion has an inner storage portion and an outer storage portion located outside the inner storage portion,
The motor with an internal brake according to claim 1 , wherein the outer accommodating portion is longer in the direction of the rotation axis than the inner accommodating portion. The brake mechanism is fixed to a case that houses the motor,
3. The motor with an internal brake according to claim 1, wherein the brake mechanism applies a braking force to a friction member that rotates together with the rotating shaft portion. The brake mechanism includes a friction member, an inner plate, an outer plate, and a guide pin.
the outer plate is fixed at a position spaced apart from the yoke in the direction of the rotation axis by the guide pin,
The inner plate is supported by the guide pin so as to be movable in the direction of the rotation axis but not rotatable,
The friction member is provided between the inner plate and the outer plate in the direction of the rotation axis.
3. The motor with an internal brake according to claim 1 or 2.

Images