JP2021046930A - Braking device - Google Patents

Abstract

To provide a braking device including brakes of two systems, which are an electromagnetic brake and a brake using a thrust force generating mechanism, and capable of maintaining and improving redundancy.SOLUTION: A braking device includes a drive motor 2, an electromagnetic brake 3, a thrust force generating mechanism 5 and a braking motor 6. A pressing member 18 of the thrust force generating mechanism 5 is incorporated into a casing 4 so as to enable movement in a motor axial direction and so as not to enable rotation in a rotor peripheral direction. A first guide part 8 engaging the case 4 with the pressing member 18 in the rotor peripheral direction to enable relative displacement of the pressing member 18 relative to the case 4 in the motor axial direction is formed in the case 4 and the pressing member 18. A second guide part 9 engaging the pressing member 18 with a brake stator 13 in the rotor peripheral direction to enable relative displacement of the brake stator 13 relative to the pressing member 18 in the motor axial direction is formed in the pressing member 18 and the brake stator 13.SELECTED DRAWING: Figure 2

Description

The present invention relates to a braking device.

For example, Japanese Patent Application Laid-Open No. 2017-12673 describes a motor with an electromagnetic brake including an electromagnetic brake by an electromagnetic force, a braking motor, and a brake by a thrust generating mechanism. According to this configuration, even when the electromagnetic brake is not energized and the braking torque due to the electromagnetic brake cannot be obtained, the pressing member of the thrust generating mechanism presses the brake stator and rubs the brake stator and the brake rotor. By engaging, the braking torque can be maintained.

Japanese Unexamined Patent Publication No. 2017-12673

In the above-mentioned motor with an electromagnetic brake, the brake stator and the pressing member are engaged with a common guide mechanism provided in the case (for example, a push rod or a guide mechanism by spline fitting). In this configuration, if the guide mechanism malfunctions (for example, clogging with dust or sticking due to deformation), both braking operations are adversely affected. That is, there is room for improvement in the above-mentioned motor with an electromagnetic brake in terms of redundancy.

An object of the present invention is to provide a braking device including two types of brakes, an electromagnetic brake and a brake by a thrust generating mechanism, which can maintain and improve redundancy.

The braking device of the present invention is a driving motor having a stator fixed to a case, a rotor that can rotate relative to the stator, and a motor shaft that rotates integrally with the rotor and is rotatably supported by the case together with the rotor. An electromagnetic brake having a brake rotor that rotates integrally with the motor shaft, a brake stator that cannot rotate in the rotation direction of the motor shaft, and a braking solenoid that frictionally engages the brake rotor and the brake stator by energizing. Then, the rotary motion is converted into a linear motion, the brake stator is moved in the axial direction of the motor shaft, a thrust force is generated to frictionally engage the brake rotor and the brake stator, and the brake rotor and the brake stator are generated. Braking including a thrust generating mechanism capable of holding the state in which the motor shaft is braked by frictionally engaging with the brake, and a braking motor for applying a torque for generating the thrust to the thrust generating mechanism. In the device, when the axial direction of the motor shaft is the motor axial direction and the circumferential direction of the rotor is the rotor circumferential direction, the thrust generating mechanism presses the brake stator in the motor axial direction in response to the thrust. A member is provided, and the pressing member is incorporated in the case so that the pressing member can move in the motor axial direction and cannot rotate in the rotor circumferential direction, and is incorporated into the case and the pressing member. The first guide portion for engaging the case and the pressing member in the rotor circumferential direction is formed so that the pressing member can move relative to the case in the motor axial direction, and the pressing member and the pressing member are formed. The brake stator is formed with a second guide portion that engages the pressing member and the brake stator in the rotor circumferential direction so that the brake stator can move relative to the pressing member in the motor axial direction. There is.

According to the present invention, the first guide portion guides the movement of the pressing member, and the second guide portion separate from the first guide portion guides the movement of the brake stator. According to this configuration, when the electromagnetic brake is activated, the brake stator moves relative to the pressing member 18 by the guide function of the second guide portion without the guide of the first guide portion. On the other hand, when the thrust generation mechanism is activated, the pressing member moves relative to the case by the guide function of the first guide portion without the guide of the second guide portion, and presses the brake stator.

Therefore, even if the second guide portion is lost due to sticking or the like, the thrust generating mechanism operates to move the pressing member while being guided by the first guide portion. At this time, the brake stator is pushed by the pressing member and moves together with the pressing member. Therefore, the state of the second guide portion (normal or failed) does not affect the movement of the pressing member and the brake stator due to the operation of the thrust generating mechanism. Further, even if the first guide portion is lost, the brake stator moves while being guided by the second guide portion by operating the electromagnetic brake. At this time, since the pressing member does not move, the state of the first guide portion does not affect the operation of the electromagnetic brake.

As described above, according to the present invention, the braking force can be generated by the electromagnetic brake regardless of the state of the first guide portion, and the braking force is generated by the thrust generating mechanism regardless of the state of the second guide portion. Can be done. That is, according to the present invention, it is possible to maintain and improve redundancy.

It is sectional drawing (when not braking) which shows the structure of the braking device of 1st Embodiment. It is a partially enlarged sectional view (during braking) of the braking device of 1st Embodiment. It is a conceptual diagram seen from one side in the axial direction which shows the pressing member of 1st Embodiment. It is a partially enlarged sectional view (during braking) of the braking device of 2nd Embodiment. It is a conceptual diagram which shows the brake stator of 2nd Embodiment, and was seen from one side in the axial direction.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each of the following embodiments, parts that are the same or equal to each other are designated by the same reference numerals in the drawings. Further, each diagram used for explanation is a conceptual diagram, and members (for example, seal members and the like) are appropriately omitted. FIG. 2 is an enlarged view of the portion surrounded by the dotted line in FIG. The overall configuration of the braking device will be described with reference to the description of JP-A-2017-112673 as appropriate.

(Overall configuration of the first embodiment)
As shown in FIGS. 1 and 2, the braking device 1 of the first embodiment includes a drive motor 2, an electromagnetic brake 3, a case 4 accommodating the drive motor 2 and the electromagnetic brake 3, and a thrust generation mechanism 5. And a braking motor 6. In the description, the axial direction of the motor shaft 23 is referred to as "motor axial direction", and the circumferential direction of the rotor 22 is referred to as "rotor circumferential direction". The circumferential direction of the rotor is the same as the circumferential direction of the motor shaft 23.

The drive motor 2 is mainly intended to be used as a drive force source for a vehicle, and is composed of, for example, a permanent magnet type synchronous motor (PM) or an induction motor (IM). The drive motor 2 includes a stator 21, a rotor 22, and a motor shaft 23. The stator 21 is fixed to the case 4. The rotor 22 is rotatable relative to the stator 21 and is fixed to the motor shaft 23 so as to rotate integrally with the motor shaft 23. The motor shaft 23 is a rotation shaft (output shaft) of the drive motor 2, and is supported by the case 4 so as to be rotatable together with the rotor 22. The stator 21 and rotor 22 are housed inside the case 4.

The electromagnetic brake 3 is an excitation-operated electromagnetic brake that operates when energized to brake the motor shaft 23. The electromagnetic brake 3 includes a brake rotor 12, a brake stator 13, and a braking solenoid 14. The electromagnetic brake 3 is configured to act so as to frictionally engage the brake rotor 12 and the brake stator 13 by energizing the braking solenoid 14, and generate braking torque. The electromagnetic brake 3 does not operate as described above when the braking solenoid 14 is not energized, and no braking torque is generated.

The brake rotor 12 is formed of a disk-shaped magnetic material. The brake rotor 12 is fixed to the motor shaft 23 so as to rotate integrally with the motor shaft 23. A friction surface 12a that contacts and engages with the friction surface 13a of the brake stator 13 described later is formed on the outer peripheral side portion (engagement portion 122 described later) of the surface of the brake rotor 12 facing the brake stator 13. There is.

The brake stator 13 is formed of an annular magnetic material. The brake stator 13 is also called an armature. The brake stator 13 is incorporated in the case 4 so that it can move in the direction of the motor shaft and cannot rotate in the direction of rotation of the motor shaft 23. A friction surface 13a is formed on the inner peripheral side portion of the surface of the brake stator 13 facing the brake rotor 12. The brake stator 13 incorporates a friction member (lining) that constitutes the friction surface 13a.

The braking solenoid 14 is composed of a yoke 141 that functions as a fixed magnetic pole, a coil 142 that is fixed to the yoke 141, and a brake stator 13 that functions as a movable magnetic pole. The coil 142 is arranged in the recess formed by the yoke 141. The coil 142 is configured to generate a magnetic attraction force by supplying a predetermined current to attract the brake stator 13 to the brake rotor 12 side. As described above, the braking solenoid 14 includes a coil 142 and a yoke 141 that forms a part of a magnetic circuit by energizing the coil 142.

Further, in the examples shown in FIGS. 1 and 2, a sub-brake stator 130 is arranged inside the case 4 so as to face the brake stator 13 via the brake rotor 12. The sub-brake stator 130 is fixed to the case 4 on the inner peripheral side of the yoke 141. A friction surface 130a is formed on the surface of the sub-brake stator 130 facing the brake rotor 12. The sub-brake stator 130 incorporates a friction member (lining) that constitutes the friction surface 130a. The sub-brake stator 130 is made of a magnetic material or a non-magnetic material. Further, a friction surface 12b is formed on the surface of the brake rotor 12 facing the friction surface 130a.

Further, according to the examples of FIGS. 1 and 2, the brake rotor 12 is composed of a boss portion 121 and an engaging portion 122. The boss portion 121 is fixed to the motor shaft 23 so as to rotate integrally with the motor shaft 23. The engaging portion 122 is formed of an annular magnetic material. The engaging portion 122 is incorporated in the boss portion 121 so that the spline hole formed on the inner peripheral surface of the engaging portion 122 and the spline shaft formed on the outer peripheral surface of the boss portion 121 are spline-fitted. .. The boss portion 121 and the engaging portion 122 are engaged with each other in the circumferential direction of the rotor. Therefore, the engaging portion 122 can rotate integrally with the motor shaft 23 and the boss portion 121, and can move relative to the motor shaft 23 and the boss portion 121 in the motor axial direction.

The brake stator 13 and the sub-brake stator 130 are arranged so as to sandwich the engaging portion 122 of the brake rotor 12. In the braking operation, the brake stator 13 moves forward by electromagnetic force or thrust, and after the brake stator 13 and the engaging portion 122 come into contact with each other, the engaging portion 122 is pushed by the brake stator 13 and moves forward together with the brake stator 13. .. Then, the engaging portion 122 comes into contact with the sub-brake stator 130 and frictionally engages with both the brake stator 13 and the sub-brake stator 130. The engaging portion 122 is separated from the sub-brake stator 130 when it is not pushed by the brake stator 13. Further, the sub-brake stator 130 may be excluded from the configuration. In this case, the brake rotor 12 is configured not to be spline-fitted, for example, an integrally molded product.

The electromagnetic brake 3 energizes the coil 142 to attract the brake rotor 12 and the brake stator 13, frictionally engage the friction surface 12a and the friction surface 13a, and in this example, the friction surface 12b and the friction surface 130a also rub against each other. It is configured to engage and brake the motor shaft 23.

The electromagnetic brake 3 is provided with a return spring 31 for avoiding contact between the friction surface 12a and the friction surface 13a when the energization of the coil 142 is cut off. As a result, in the initial state (a state in which neither of the two brakes is operating), the brake stator 13 is separated from the brake rotor 12, and the brake stator 13 approaches (for example, abuts) the pressing member 18. The sub-brake stator 130 is also separated from the brake rotor 12 in the initial state. The brake rotor 12, the brake stator 13, the sub-brake stator 130, and the braking solenoid 14 are housed inside the case 4.

The braking device 1 can maintain the state in which the motor shaft 23 is braked by frictionally engaging the brake stator 13 and the brake rotor 12 even when the energization of the braking solenoid 14 of the electromagnetic brake 3 is lost. It is configured to be possible. Therefore, the braking device 1 is provided with a thrust generating mechanism 5 and a braking motor 6.

The thrust generating mechanism 5 converts the rotational motion into a linear motion to generate a thrust force that presses the brake stator 13 toward the brake rotor 12 in the motor axial direction, and also causes the brake stator 13 and the brake rotor 12 to be frictionally engaged with each other. It is an operating device capable of holding the braked state of the motor shaft 23. The thrust generation mechanism 5 of the first embodiment is configured by using the feed screw mechanism 17 as an example.

Specifically, the thrust generation mechanism 5 includes a feed screw mechanism 17 and a pressing member 18. The pressing member 18 is formed in a disk shape (which can also be said to be an annular shape). The pressing member 18 is incorporated in the case 4 so that it can move in the motor shaft direction and cannot rotate in the rotation direction (rotor circumferential direction) of the motor shaft 23.

The pressing member 18 of the first embodiment is incorporated in the case 4 so that the spline hole formed inside the case 4 and the spline shaft formed on the outer peripheral surface of the pressing member 18 are spline-fitted. Therefore, the pressing member 18 is configured to press the brake stator 13 by being moved forward in the motor axial direction by the thrust generating mechanism 5.

A female screw portion 17a of the feed screw mechanism 17 is formed at the central portion (inner peripheral portion) of the pressing member 18 in the radial direction. The braking motor 6 is adjacent to the pressing member 18 in the motor axial direction, is arranged outside the case 4, and is fixed to the case 4. The braking motor 6 is a device that applies torque for generating thrust to the thrust generating mechanism 5.

A male screw portion 17b of the feed screw mechanism 17 is formed on the outer peripheral surface of the output shaft 6a of the braking motor 6. The output shaft 6a protrudes to one side in the motor axis direction of the case (not shown) of the braking motor 6, and the braking motor 6 is fixed to the case 4 to enter the inside of the case 4. Then, the male screw portion 17b formed on the output shaft 6a of the braking motor 6 is screwed into the female screw portion 17a formed on the pressing member 18, thereby forming the feed screw mechanism 17. The female screw portion 17a and the male screw portion 17b of the lead screw mechanism 17 are formed of, for example, a ball screw, a trapezoidal screw, or a square screw.

The feed screw mechanism 17 rotates the output shaft 6a, that is, the male screw portion 17b in the forward rotation direction (predetermined rotation direction) by the braking motor 6, thereby moving the pressing member 18 in the forward direction in the motor axial direction (thrust force). ) Is generated. Further, the feed screw mechanism 17 generates an axial force for moving the pressing member 18 in the backward direction in the motor axial direction by rotating the male screw portion 17b in the reverse direction (opposite direction of the predetermined rotation direction) by the braking motor 6. Let me.

Therefore, the thrust generating mechanism 5 uses the feed screw mechanism 17 as described above to apply torque in the forward rotation direction to the feed screw mechanism 17 by the braking motor 6, thereby causing the thrust mechanism 17 to apply a thrust in the forward direction. Can be generated and the pressing member 18 can be moved in the forward direction. As a result, the brake stator 13 can be moved toward the brake rotor 12 in the motor shaft direction, and the brake rotor 12 and the brake stator 13 can be frictionally engaged with each other to brake the motor shaft 23. Further, by applying a torque in the reverse direction to the feed screw mechanism 17 by the braking motor 6, the pressing member 18 is moved in the backward direction, and the force pressing the brake stator 13 toward the brake rotor 12 is released. Can be done. That is, the braking of the motor shaft 23 by the thrust generation mechanism 5 can be released.

(1st guide part)
The braking device 1 further includes a first guide unit 8 and a second guide unit 9. Specifically, the case 4 and the pressing member 18 have a first guide portion that engages the case 4 and the pressing member 18 in the rotor circumferential direction so that the pressing member 18 can move relative to the case 4 in the motor axial direction. 8 is formed. The first guide portion 8 is configured to guide only the pressing member 18.

As a specific example, as shown in FIGS. 2 and 3, the first guide portion 8 is provided on the outer peripheral surface of the first engaging portion 81 provided in the case 4 to form the spline hole and the pressing member 18, and the spline shaft. It is composed of the first engaged portion 82 forming the above. The first engaged portion 82 engages with the first engaging portion 81 in the rotor circumferential direction. The first guide portion 8 is formed of the pressing member 18 and the case 4, but is not formed between the brake stator 13 and the case 4.

The first engaging portion 81 is an annular member integrally fixed to the case 4, and a spline hole extending in the motor axial direction is formed on the inner peripheral surface. The first engaging portion 81 is provided inside the case 4 so as to project from, for example, a part of the case 4 in the motor axial direction. The first engaging portion 81 may be configured by forming a spline hole integrally with the inner peripheral surface of the case 4, that is, on the inner peripheral surface of the case 4.

The first engaged portion 82 is a portion that protrudes from the outer peripheral surface of the pressing member 18 and forms a spline shaft extending in the motor axial direction. The first engaging portion 81 and the first engaged portion 82 are engaged, and the spline hole and the spline shaft are spline-fitted. The first engaging portion 81 and the first engaged portion 82 are formed so as to maintain the engaged state even when the pressing member 18 moves forward as much as possible within the movable range.

As shown in FIG. 3, a plurality of spline shafts are provided on the outer peripheral surface of the pressing member 18 at intervals (here, at equal intervals) in the circumferential direction of the rotor. A plurality of spline holes formed by the first engaging portion 81 are also provided corresponding to the spline shaft. At the outer peripheral portion of the pressing member 18, a plurality of concave portions and convex portions are engaged. The pressing member 18 is composed of a central portion 180 having a female screw portion 17a formed on the inner peripheral surface and a first engaged portion 82 provided on the outer peripheral surface of the central portion 180 to form a plurality of spline shafts. It can be said that it has been done.

When the braking motor 6 is driven in the forward rotation direction, the pressing member 18 at the initial position (in the initial state) moves forward while being guided in the motor axial direction by the first guide portion 8. That is, the pressing member 18 is guided by the first guide portion 8 and moves relative to the case 4 in the motor axial direction. The brake stator 13 moves forward integrally with the pressing member 18 while being pushed by the pressing member 18 guided by the first guide portion 8, and comes into contact with and frictionally engages with the brake rotor 12. At this time, the torque received by the brake stator 13 is transmitted to the pressing member 18 via the second guide portion 9 described later, and is received by the first guide portion 8. That is, the first guide portion 8 has a guide function of the pressing member 18 and a torque receiving function of receiving torque during braking. The pressing member 18 is also guided in the motor axial direction by the first guide portion 8 even when the pressing member 18 is moved backward. At this time, the brake stator 13 moves backward by the urging force of the return spring 31 while being guided by the second guide portion 9.

(2nd guide part)
A second guide portion 9 that engages the pressing member 18 and the brake stator 13 with the pressing member 18 and the brake stator 13 in the rotor circumferential direction so that the brake stator 13 can move relative to the pressing member 18 in the motor axial direction. Is formed. The second guide portion 9 is configured to guide only the brake stator 13.

The second guide portion 9 of the first embodiment has a recess in the second engaging portion 91 protruding in the motor axial direction from the end surface of the pressing member 18 on the brake stator 13 side and the end surface of the brake stator 13 on the pressing member 18 side. It is composed of a second engaged portion 92 to be formed. The second engaged portion 92 engages with the second engaging portion 91 in the rotor circumferential direction.

The second engaging portion 91 is a portion of the pressing member 18 formed in a rod shape (for example, a columnar or prismatic shape). The second engaged portion 92 is a portion of the brake stator 13 that forms a recess into which the second engaging portion 91 can be inserted. For example, as shown in FIG. 3, when the second engaging portion 91 is cylindrical, the inner diameter of the recess formed by the second engaged portion 92 (see the dotted line in FIG. 3) is the inner diameter of the second engaging portion 91. Larger than the outer diameter. The second engaging portion 91 and the second engaged portion 92 are formed so that the engaged state can be maintained even when the brake stator 13 and the pressing member 18 are separated as much as possible within the movable range. A plurality of second engaging portions 91 are formed on the pressing member 18 in the circumferential direction. Further, the second engaged portion 92 is provided corresponding to the second engaging portion 91.

When the braking solenoid 14 is energized and the electromagnetic brake 3 functions, the brake stator 13 in the initial position (in the initial state) is guided in the motor axial direction by the second guide portion 9, and is moved to the brake rotor 12 side by electromagnetic force. It is sucked and moves forward. At this time, the pressing member 18 does not move, and the brake stator 13 is guided by the second guide portion 9 and moves relative to the pressing member 18 in the motor axial direction. Then, the brake stator 13 comes into contact with the brake rotor 12 and is frictionally engaged with the brake rotor 12. When the electromagnetic brake 3 is stopped, the brake stator 13 moves backward while being guided by the second guide portion 9 in the motor axial direction by the urging force of the return spring 31.

(Effect of the first embodiment)
According to the first embodiment, the first guide portion 8 guides the movement of the pressing member 18, and the second guide portion 9 separate from the first guide portion 8 guides the movement of the brake stator 13. According to this configuration, when the electromagnetic brake 3 is activated, the brake stator 13 moves relative to the pressing member 18 by the guide function of the second guide portion 9 without the guide of the first guide portion 8. On the other hand, when the thrust generation mechanism 5 is activated, the pressing member 18 moves relative to the case 4 by the guide function of the first guide portion 8 without the guide of the second guide portion 9, and presses the brake stator 13. ..

Therefore, even if the second guide portion 9 is lost due to sticking or the like, the thrust generation mechanism 5 operates to move the pressing member 18 while being guided by the first guide portion 8. At this time, the brake stator 13 is pushed by the pressing member 18 and moves together with the pressing member 18. Therefore, the state (normal or failed) of the second guide portion 9 does not affect the movement of the pressing member 18 and the brake stator 13 due to the operation of the thrust generating mechanism 5. Further, even if the first guide portion 8 is lost, the brake stator 13 moves while being guided by the second guide portion 9 by operating the electromagnetic brake 3. At this time, since the pressing member 18 does not move, the state of the first guide portion 8 does not affect the operation of the electromagnetic brake 3.

As described above, according to the first embodiment, the braking force can be generated by the electromagnetic brake 3 regardless of the state of the first guide unit 8, and the thrust generation mechanism 5 can generate the braking force regardless of the state of the second guide unit 9. Braking force can be generated. That is, according to the first embodiment, it is possible to maintain / improve redundancy.

(Other forms of the first embodiment)
The configuration of the first guide unit 8 and the second guide unit 9 is not limited to the above embodiment. For example, the first guide portion 8 is not limited to the structure of spline fitting, and like the second guide portion 9, a rod-shaped portion (convex portion) extending in the motor axial direction and a hole forming portion (concave portion) engaged with the rod-shaped portion (convex portion). It may be composed of and. In this case, one of the convex portion and the concave portion is formed on the pressing member 18, and the other of the convex portion and the concave portion is formed on the case 4. Even with this configuration, as in the above embodiment, the first guide unit 8 is independent of the second guide unit 9, and can exhibit a guide function and a torque receiving function. Here, the convex portion may protrude in the motor axial direction, or may protrude in the radial direction (rotor radial direction) like the spline shaft. The concave portion is provided so as to engage with the convex portion corresponding to the protruding direction of the convex portion.

In the second guide portion 9, one of the convex portion and the concave portion is formed on the pressing member 18, and the other of the convex portion and the concave portion is formed on the brake stator 13. For example, the brake stator 13 may be formed with a convex portion as the second engaged portion 92, and the pressing member 18 may be formed with a concave portion as the second engaged portion. Further, similarly to the above, the convex portion may protrude in the motor axial direction, or may protrude in the radial direction (rotor radial direction) like the spline shaft. The concave portion is provided so as to engage with the convex portion corresponding to the protruding direction of the convex portion.

Further, the convex portion may be formed integrally with the pressing member 18 or the brake stator 13, or may be formed by incorporating a rod-shaped member into the concave portion provided in the pressing member 18 or the brake stator 13. Further, the thrust generation mechanism 5 may be composed of, for example, a rack and a pinion.

(Second Embodiment)
The braking device of the second embodiment is the one in which the heat insulating layers 71 and 72 are added to the configuration of the first embodiment. Therefore, the added configuration will be mainly described below. In the description of the second embodiment, the description and drawings of the first embodiment can be referred to.

As shown in FIGS. 4 and 5, the brake stator 13 of the second embodiment includes a first portion 131 arranged to face the yoke 141 and the coil 142, and a second portion 132 arranged to face the brake rotor 12. A first heat insulating layer (corresponding to a "heat insulating layer") 71, which is arranged between the first portion 131 and the second portion 132, is provided.

The first portion 131 is formed of a magnetic material (for example, a magnetic material metal such as iron). The second portion 132 is formed of a non-magnetic material (for example, a non-magnetic metal such as aluminum). The thermal conductivity of the second site 132 is lower than that of the first site 131. Further, the sub-brake stator 130 is also formed of, for example, a non-magnetic material having a relatively low thermal conductivity with respect to a magnetic material, like the second portion 132. The lining portion (friction member) of the second portion 132 may be formed of a non-magnetic material different from the other portions of the second portion 132.

The first heat insulating layer 71 is a cylindrical heat insulating material, and connects the first portion 131 and the second portion 132. The first heat insulating layer 71 is fixed (for example, adhered) to the inner peripheral surface of the first portion 131 and the outer peripheral surface of the second portion 132. The first heat insulating layer 71 in the example of FIG. 4 is arranged in the entire motor axial direction of the brake stator 13 so as to completely separate the first portion 131 and the second portion 132. In this example, the first heat insulating layer 71 is arranged on the entire inner peripheral surface of the first portion 131 and the entire outer peripheral surface of the second portion 132.

Here, when the radial direction of the rotor 22 (the same as the radial direction of the motor shaft 23, the brake stator 13, the pressing member 18, etc.) is referred to as the "rotor radial direction", the first heat insulating layer 71 is the first guide portion 8. And, it is arranged inside the rotor radial direction with respect to the second guide portion 9. In other words, the first guide portion 8 and the second guide portion 9 are located outside the rotor radial direction with respect to the first heat insulating layer 71. The second engaged portion 92 of the second guide portion 9 is provided in the first portion 131.

Further, a second heat insulating layer 72 is arranged between the inner peripheral surface of the yoke 141 and the outer peripheral surface of the sub brake stator 130. The second heat insulating layer 72 is a cylindrical heat insulating material and is fixed (for example, adhered) to at least one of the case 4, the sub brake stator 130, and the yoke 141. The second heat insulating layer 72 in the example of FIG. 4 is arranged at least in the entire motor axial direction of the sub brake stator 130 so as to completely separate the yoke 141 and the sub brake stator 130. In a configuration without the sub-brake stator 130 (a configuration in which one brake stator 13 and the brake rotor 12 are frictionally engaged with each other), the second heat insulating layer 72 can be omitted.

(Effect of the second embodiment)
It is assumed that the braking device 1 which is a motor with a brake is used as, for example, an inboard brake. In this case, since the braking device 1 is arranged inside the vehicle body, cooling by the air flow is difficult to function, and a separate means for cooling the frictional heat is required. Therefore, when the braking device 1 is used as an inboard brake, for example, a known oil cooling system using cooling oil is added (see, for example, Japanese Patent Application Laid-Open No. 2017-145915). However, when an oil cooling system is added, the size of the device becomes large. In addition, if an oil cooling system is used, dragging due to oil may occur.

On the other hand, in the inboard brake, if the frictional heat cannot be sufficiently cooled without using the oil cooling system, the constituent members may be thermally deformed. When thermal deformation occurs in the constituent members, the guide mechanism is likely to be stuck and the function of the braking solenoid 14 (magnetic circuit) is likely to be deteriorated. Each dimension of the magnetic circuit configuration is strictly designed. As described above, the deformation of the constituent members due to the frictional heat is a factor that lowers the guide function and the function of the magnetic circuit, and lowers the redundancy.

Here, according to the second embodiment, since the braking device 1 is provided with the first heat insulating layer 71 and the second heat insulating layer 72, the heat generated by the frictional engagement is generated in the yoke 141 and the first portion 131. It becomes difficult to transmit to the constructed magnetic circuit. As a result, thermal deformation of the constituent members of the magnetic circuit is suppressed, and functional deterioration of the magnetic circuit is suppressed. That is, according to the second embodiment, the function of the electromagnetic brake 3 is maintained, and the redundancy can be maintained / improved while suppressing the increase in size and drag of the device.

Further, according to the second embodiment, a non-magnetic material is used as the second portion 132. That is, the designer can adopt a material having a lower thermal conductivity than the first portion 131 as the second portion 132. As a result, the transfer of frictional heat to the magnetic circuit side is further suppressed.

Further, in the second embodiment, the second guide portion 9 is located outside the rotor radial direction with respect to the first heat insulating layer 71. Therefore, the first heat insulating layer 71 cuts off the movement of heat outward in the rotor radial direction, and the thermal deformation of the constituent members of the second guide portion 9 is suppressed. That is, the guide of the second guide unit 9 is maintained, and the redundancy is maintained / improved.

Further, since the first guide portion 8 is also located outside the rotor radial direction with respect to the first heat insulating layer 71, the guide function of the first guide portion 8 is maintained by the same principle as described above. Due to the configuration in which at least one of the first guide portion 8 and the second guide portion 9 is located outside the first heat insulating layer 71 in the rotor radial direction, at least one guide function is maintained and redundancy is improved. If it is permissible to increase the size of the device, a cooling structure such as an oil cooling system may be combined with the configuration of the second embodiment. This ensures redundancy more reliably.

(Other forms of the second embodiment)
The configuration including the heat insulating layers 71 and 72 is not limited to the above embodiment. For example, the heat insulating layers 71 and 72 may partially include an air layer (gap). The air layer has heat insulating performance. Further, the first heat insulating layer 71 may be arranged in a part of the brake stator 13 in the motor axial direction. This also suppresses the transfer of frictional heat to the magnetic circuit. In this way, the first heat insulating layer 71 is arranged so as to cover at least a part of the outer peripheral surface of the second portion 132 in the motor axial direction. When the first heat insulating layer 71 is arranged in a part of the outer peripheral surface of the second portion 132 in the motor axial direction, the first heat insulating layer 71 is in the motor axial direction from the end surface of the brake stator 13 on the brake rotor 12 side (FIG. 1). It is preferable that the device is arranged so as to extend in the right direction of the). By insulating the side where frictional heat is generated, heat transfer can be suppressed.

Like the first heat insulating layer 71, the second heat insulating layer 72 may be arranged in a part of the sub brake stator 130 in the motor axial direction. This also suppresses the transfer of frictional heat to the magnetic circuit. In this way, the second heat insulating layer 72 is arranged so as to cover at least a part of the outer peripheral surface of the sub-brake stator 130 in the motor axial direction. When the second heat insulating layer 72 is arranged on a part of the outer peripheral surface of the sub brake stator 130 in the motor axial direction, the second heat insulating layer 72 is in the motor axial direction from the end surface of the sub brake stator 130 on the brake rotor 12 side (FIG. It is preferable that the device is arranged so as to extend in the left direction of 1. By insulating the side where frictional heat is generated, heat transfer can be suppressed.

Further, the first guide portion 8 and / or the second guide portion 9 may be arranged inside the first heat insulating layer 71 in the rotor radial direction. This also suppresses at least thermal deformation of the components of the magnetic circuit. Further, the second portion 132 and / or the sub brake stator 130 may be formed of a magnetic material. Further, the braking device 1 of the first embodiment and the second embodiment is not limited to the inboard brake, and the drive motor and its braking function can be appropriately arranged at a required place.

1 ... Brake device, 12 ... Brake rotor, 13 ... Brake stator, 131 ... 1st part, 132 ... 2nd part, 14 ... Braking solenoid, 141 ... Yoke, 142 ... Coil, 18 ... Pressing member, 2 ... For driving Motor, 21 ... Solenoid, 22 ... Rotor, 23 ... Motor shaft, 5 ... Thrust generation mechanism, 6 ... Braking motor, 71 ... First heat insulating layer (heat insulating layer), 8 ... 1st guide, 9 ... 2nd guide Department.

Claims (4)

A stator fixed to the case, a rotor that can rotate relative to the stator, and a drive motor that has a motor shaft that rotates integrally with the rotor and is rotatably supported by the case together with the rotor.
An electromagnetic brake having a brake rotor that rotates integrally with the motor shaft, a brake stator that cannot rotate in the rotation direction of the motor shaft, and a braking solenoid that frictionally engages the brake rotor and the brake stator by energizing the motor shaft.
The rotary motion is converted into a linear motion, the brake stator is moved in the axial direction of the motor shaft, a thrust force is generated to frictionally engage the brake rotor and the brake stator, and the brake rotor and the brake stator are brought together. A thrust generating mechanism capable of frictionally engaging to maintain the braked state of the motor shaft,
A braking motor that applies torque to generate the thrust to the thrust generation mechanism, and
In the braking device equipped with
Assuming that the axial direction of the motor shaft is the motor axial direction and the circumferential direction of the rotor is the rotor circumferential direction,
The thrust generation mechanism includes a pressing member that presses the brake stator in the motor axial direction in response to the thrust.
The pressing member is incorporated in the case so that it can move in the motor axial direction and cannot rotate in the rotor circumferential direction.
The case and the pressing member are formed with a first guide portion that engages the case and the pressing member in the rotor circumferential direction so that the pressing member can move relative to the case in the motor axial direction. Being done
A second guide for engaging the pressing member and the brake stator in the rotor circumferential direction so that the brake stator can move relative to the pressing member in the motor axial direction. A braking device in which a part is formed. The braking solenoid includes a coil and a yoke that forms a part of a magnetic circuit by energizing the coil.
The brake stator is a heat insulating component arranged between a first portion arranged to face the yoke and the coil, a second portion arranged to face the brake rotor, and the first portion and the second portion. The braking device according to claim 1, further comprising a layer. The first part is made of a magnetic material and is made of a magnetic material.
The braking device according to claim 2, wherein the second portion is made of a non-magnetic material. When the radial direction of the rotor is the radial direction of the rotor,
The braking device according to claim 2 or 3, wherein at least one of the first guide portion and the second guide portion is located outside the heat insulating layer in the radial direction of the rotor.

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