An integrated structure of an axial magnetic field motor and a double friction surface brake

Abstract

The present invention provides an integrated structure of an axial magnetic field motor and a double friction surface brake, comprising a rotor assembly, including a back iron, a shaft and a magnetic steel, wherein the magnetic steel is fixed to the back iron and arranged around the shaft, and a limiting platform is arranged on the shaft; the motor stator assembly comprises a stator core and a stator winding, wherein the stator core is sleeved on the shaft and located between the limiting platform and the magnetic steel, so that the stator core fixes the stator winding on one side and is arranged opposite to the magnetic steel; a brake disc is sleeved on the shaft, the brake disc is located on a side of the motor stator assembly away from the magnetic steel, and a limiting groove cooperating with the limiting platform is provided on the brake disc; the brake stator assembly comprises a shell, a coil, a movable plate and a spring, the spring is connected between the shell and the movable plate, the coil is fixed to a side of the shell facing the movable plate, and the shell is fixed to a side of the motor stator assembly away from the magnetic steel, so that the brake disc can overcome the spring elastic force and be located between the movable plate and the motor stator assembly, thereby shortening the axial dimension of the overall structure.

Description

Technical Field

[0001] The invention relates to the technical field of motors, and in particular to an integrated structure of an axial magnetic field motor and a double friction surface brake. Background Art

[0002] The joint module of the robot arm is driven by a motor, and a brake is required to keep the position when the power is off. The existing motor and brake are two independent structures, which makes the overall axial dimension of the assembly longer. In addition, most robot arms are multi-axis, such as four-axis, six-axis and seven-axis, which limits the installation space of the motor and cannot be applied to the above-mentioned assembly structure with a long axial dimension. Summary of the invention

[0003] In order to solve the above problems, the present invention provides an integrated structure of an axial magnetic field motor and a double friction surface brake with a short axial dimension and a compact structure.

[0004] An integrated structure of an axial magnetic field motor and a double friction surface brake, comprising:

[0005] The rotor assembly comprises a back iron, a shaft and a plurality of magnetic steels, wherein the back iron is connected to the shaft, and the plurality of magnetic steels are fixed to the back iron and arranged around the shaft;

[0006] The motor stator assembly comprises a stator core and a stator winding, wherein the stator winding is fixed on the stator core, and the stator core is sleeved on the shaft and located between the limit platform and the magnetic steel, so that the stator core is fixed to a side of the stator winding and is arranged opposite to the magnetic steel;

[0007] A brake disc, sleeved on the shaft, the brake disc is located on a side of the motor stator assembly away from the magnetic steel;

[0008] The brake stator assembly includes a shell, a coil, a movable plate and at least one spring, wherein the spring is connected between the shell and the movable plate, the coil is fixed to the side of the shell facing the movable plate, and the shell is fixed to the side of the motor stator assembly away from the magnetic steel, so that the brake disc can overcome the spring force and be located between the movable plate and the motor stator assembly.

[0009] Furthermore, at least one limit platform is arranged on the shaft portion, the limit platform and the magnetic steel are located on the same side of the back iron, and a limit groove cooperating with the limit platform is opened on the brake disc.

[0010] Furthermore, the motor stator assembly also includes:

[0011] A fixing plate is fixed on the stator core and is located on a side of the stator core away from the stator winding.

[0012] Furthermore, friction plates opposite to the movable plate and the fixed plate are fixed to both sides of the brake disc in the axial direction.

[0013] Furthermore, at least one supporting portion is provided on the shell, and the shell is connected to the fixing plate via the supporting portion.

[0014] Furthermore, the movable plate is provided with an avoidance hole for avoiding the support part.

[0015] Furthermore, a coil slot for mounting the coil is provided on a side of the shell facing the movable plate.

[0016] Furthermore, a spring groove for installing the spring is provided on a side of the shell facing the movable plate.

[0017] Furthermore, a plurality of the support portions are arranged at intervals along the outer periphery of the shell, and a spring groove is provided between two adjacent support portions.

[0018] Furthermore, a plurality of the support portions surround the outside of the brake disc.

[0019] Compared with the prior art, this technical solution has the following advantages:

[0020] Since the motor stator assembly, the brake disc and the brake stator assembly are integrated on the shaft of the rotor assembly, the axial dimension of the overall structure is further shortened to meet the limited space size of the motor and the structure is compact. In addition, the fixing plate of the motor stator assembly also serves as a fixing plate that rubs against the brake disc, further shortening the circumferential dimension of the motor.

[0021] The present invention is further described below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural exploded view of a preferred embodiment of the integrated structure of the axial magnetic field motor and the double friction surface brake according to the present invention;

[0023] Figure 2 is a structural schematic diagram of the above preferred embodiment of the integrated structure of the axial magnetic field motor and the double friction surface brake according to the present invention;

[0024] Figure 3 is a cross-sectional view of the above preferred embodiment of the integrated structure of the axial magnetic field motor and the double friction surface brake according to the present invention;

[0025] Figure 4 is an exploded view of a preferred embodiment of the motor stator assembly according to the present invention;

[0026] Figure 5 is a schematic structural view of the above-mentioned preferred embodiment of the motor stator assembly according to the present invention;

[0027] Figure 6 is a cross-sectional view of the above-mentioned preferred embodiment of the motor stator assembly according to the present invention;

[0028] Figure 7 is an exploded view of a preferred embodiment of the brake stator assembly according to the present invention;

[0029] Figure 8 is a schematic structural view of the above-mentioned preferred embodiment of the brake stator assembly according to the present invention;

[0030] Figure 9 is a cross-sectional view of the above-mentioned preferred embodiment of the brake stator assembly according to the present invention;

[0031] Figure 10 is a schematic structural view of a preferred embodiment of the rotor assembly according to the present invention;

[0032] Figure 11 is a schematic structural view of a preferred embodiment of the rotor shaft according to the present invention;

[0033] Figure 12 is a schematic structural view of a preferred embodiment of the rotor disc according to the present invention;

[0034] Figure 13 is a cross-sectional view of the above-mentioned preferred embodiment of the rotor disc according to the present invention;

[0035] Figure 14 is a schematic structural view of the non-operating mode of the integrated structure of the axial magnetic field motor and the double friction surface brake according to the present invention;

[0036] Figure 15 is a schematic structural view of the operating mode of the integrated structure of the axial magnetic field motor and the double friction surface brake according to the present invention. Detailed implementation manners

[0037] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments in the following description are only examples, and those skilled in the art can think of other obvious variations. The basic principles defined in the following description of the present invention can be applied to other implementation schemes, variant schemes, improvement schemes, equivalent schemes, and other technical schemes that do not depart from the spirit and scope of the present invention.

[0038] Those skilled in the art should understand that, in the disclosure of the present invention, the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating the orientation or position relationship are based on the orientation or position relationship shown in the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the above terms should not be understood as limiting the present invention.

[0039] It is to be understood that the term "one" should be understood as "at least one" or "one or more", that is, in one embodiment, the number of an element may be one, while in another embodiment, the number of the element may be multiple, and the term "one" should not be understood as a limitation on the quantity.

[0040] like Figures 1 to 13 As shown, the integrated structure of the axial magnetic field motor and the double friction surface brake includes:

[0041] The rotor assembly 100 includes a back iron 110, a shaft 120 and a plurality of magnetic steels 130, wherein the back iron 110 is connected to the shaft 120, the plurality of magnetic steels 130 are fixed to the back iron 110 and arranged around the shaft 120, and at least one limiting platform 121 is arranged on the shaft 120, and the limiting platform 121 and the magnetic steels 130 are located on the same side of the back iron 110;

[0042] The motor stator assembly 200 includes a stator core 210 and a stator winding 220, wherein the stator winding 220 is fixed to the stator core 210, and the stator core 210 is sleeved on the shaft 120 and located between the limiting platform 121 and the magnetic steel 130, so that the side of the stator core 210 fixing the stator winding 220 is arranged opposite to the magnetic steel 130;

[0043] A brake disc 300 is sleeved on the shaft 120 , the brake disc 300 is located on a side of the motor stator assembly 200 away from the magnetic steel 130 , and a limiting groove 310 is provided on the brake disc 300 to cooperate with the limiting platform 121 ;

[0044] The brake stator assembly 400 includes a housing 410, a coil 420, a movable plate 430, and at least one spring 440. The spring 440 is connected between the housing 410 and the movable plate 430. The coil 420 is fixed to one side of the housing 410 facing the movable plate 430. The housing 410 is fixed to one side of the motor stator assembly 200 facing away from the magnet 130, so that when the coil 420 and the stator winding 220 are not powered on, the brake disc 430 can overcome the elastic force of the spring 440 and abut between the movable plate 430 and the motor stator assembly 200, thereby achieving the function of braking the rotor assembly 100.

[0045] Since the motor stator assembly 200, the brake disc 300, and the brake stator assembly 400 are integrated on the shaft portion 120 of the rotor assembly 100, the axial dimension of the overall structure is further shortened to meet the limited space size of the motor.

[0046] As Figure 10 and Figure 11 shown, the rotor assembly 100 includes a back iron 110, a shaft portion 120, and a plurality of magnets 130. The cross-sections of the back iron 110 and the shaft portion 120 can be circular, and the two can be coaxially arranged. And the axial dimension of the back iron 110 is small, that is, the back iron 110 is thin, and the axial dimension of the shaft portion 120 is long. A plurality of the magnets 130 are fixed on the back iron 110 and are arranged around the shaft portion 120, so that the plurality of magnets 130 are arranged in a ring shape. Among them, the magnet 130 can be in a fan-shaped structure, and two adjacent magnets 130 are arranged at intervals.

[0047] At least one limiting platform 121 is arranged on the shaft portion 120 and is used to cooperate with the limiting groove 310 on the brake disc 300, so that the brake disc 300 can move along the axial direction of the shaft portion 120. Refer to Figure 1 and Figure 3 . Specifically, the length direction of the limiting platform 121 is parallel to the axial direction of the shaft portion 120, and the length of the limiting platform 121 is longer than the thickness of the brake disc 300.

[0048] The number of the limiting platforms 121 can be three, and they are arranged at equal intervals along the outer periphery of the shaft portion 120. Correspondingly, the number of the limiting grooves 310 on the brake disc 300 is also three, and each limiting platform 121 corresponds to one limiting groove 310. Refer to Figure 12 . Of course, the number of the limiting platforms 121 can also be two or more. By increasing the number of the limiting platforms 121 and the limiting grooves 310, the stability of the brake disc 300 moving along the axial direction of the shaft portion 120 is improved.

[0049] Continue to refer Figure 10 and Figure 11 The limit platform 121 and the magnetic steel 130 are located on the same side of the back iron 110 , and there is a certain distance between the two, so that the motor stator assembly 200 sleeved on the shaft 120 is located between the limit platform 121 and the magnetic steel 130 .

[0050] like Figure 3 As shown, the shaft portion 120 may be a tubular structure.

[0051] like Figures 4 to 6 As shown, the motor stator assembly 200 includes a stator core 210 and a stator winding 220. The stator core 210 is annular in structure. The stator core 210 is provided with a plurality of winding mounting grooves 211 along its radial direction so that the stator core 210 is divided into a plurality of teeth 212 for winding the stator winding 220. The stator winding 220 is wound around the outside of the tooth 212 along the mounting grooves 211.

[0052] The motor stator assembly 200 further includes a fixing plate 230, which is annular in shape, and the stator core 210 can be fixed on the fixing plate 230, and the stator winding 220 is fixed on a side of the stator core 210 away from the fixing plate 230. That is, the winding installation groove 211 is provided on a side of the stator core 210 away from the fixing plate 230.

[0053] Preferably, the stator core 210 is fixed to the fixing plate 230 by a first fastener 240. The first fastener 240 may be a bolt.

[0054] Since the stator core 210 and the fixing plate 230 are both annular, the assembled motor stator assembly 200 is also annular, so as to be sleeved outside the shaft 120 and located between the limiting platform 121 and the magnetic steel 130. When the motor stator assembly 200 is sleeved outside the shaft 120, the stator core 210 fixes one side of the stator winding 220 and is arranged opposite to the magnetic steel 130, and an air gap a is maintained between the stator core 210 and the magnetic steel 130, so that the rotor assembly 100 rotates relative to the motor stator assembly 200, referring to Figure 3 .

[0055] like Figure 12 and Figure 13 The brake disc 300 is annular in structure, and a plurality of limiting grooves 310 are formed on the inner wall thereof. The plurality of limiting grooves 310 are arranged at equal intervals along the inner periphery of the brake disc 300 .

[0056] The brake disc 300 is respectively fixed with friction plates 320 on both sides of the axis direction, and the friction plates 320 are also annular, so that the brake disc 300 can be sleeved on the shaft portion 120, and abut between the motor stator assembly 200 and the movable plate 430 through the friction plates 320 on both sides. Figure 3 Specifically, the brake disc 300 is sleeved outside the shaft portion 120 and is located on a side of the motor stator assembly 200 away from the magnetic steel 130 , so that the friction plate 320 on the brake disc 300 can abut against the fixing plate 230 .

[0057] like Figures 7 to 9 As shown, the brake stator assembly 400 includes a housing 410, a coil 420, a movable plate 430 and at least one spring 440. The housing 410, the coil 420 and the movable plate 430 are all annular, so that the assembled brake stator assembly 400 also has an annular structure, which is sleeved on the shaft 120 and located on the side of the brake disc 300 away from the motor stator assembly 200. When the housing 410 is fixed to the fixed plate 230, the two sides of the brake disc 300 are respectively abutted between the movable plate 430 and the fixed plate 230 through the friction plate 320. Figure 1 and Figure 3 .

[0058] Specifically, at least one supporting portion 411 is disposed on the housing 410 , and the housing 410 is connected to the fixing plate 230 via the supporting portion 411 , so that there is a distance between the housing 410 and the fixing portion 410 to accommodate the movable plate 430 and the brake disc 300 .

[0059] Preferably, the number of the support portions 411 is three, and they are arranged at equal intervals along the outer periphery of the support portion 411. Of course, the number of the support portions 411 may also be two or more.

[0060] More preferably, the housing 410 is fixed to the fixing plate 230 by a second fastener 500. Specifically, the housing 410 is provided with the sleeve holes 414 for the second fastener 500 to pass through, the number of the sleeve holes 414 is the same as the number of the support portion 411, and the sleeve holes 414 are located inside the support portion 411, and the second fastener 500 passes through the sleeve holes 414 and is screwed to the fixing plate 230, thereby fixing the housing 410 to the fixing plate 230. The second fastener 500 may be a bolt.

[0061] The housing 410 and the support portion 411 may be integrally formed.

[0062] As shown Figure 7 in the figure, on one side of the housing 410 where the support portion 411 is provided, a coil groove 412 for installing the coil 420 is opened. The coil groove 412 is annular so that the annular coil 420 is installed in the coil groove 412. Wherein the support portion 411 surrounds the outside of the coil groove 412.

[0063] Continuing to refer Figure 7 to the figure, on one side of the housing 410 where the support portion 411 is provided, a spring groove 413 for installing the spring 440 is opened. The spring groove 413 surrounds the outside of the coil groove 412.

[0064] In one example, a spring groove 413 is opened between two adjacent support portions 411. At this time, the number of spring grooves 413 is three, and each spring groove 413 is installed with a spring 440. Of course, the number of spring grooves 413 can be two or more. By increasing the number of springs 440 and arranging them evenly, the brake disc 300 can be evenly stressed in the brake stator assembly 400, and the movement of overcoming the elastic force of the spring 440 is stable.

[0065] Continuing to refer Figure 7 to the figure, an avoidance hole 431 for avoiding the support portion 411 is opened on the movable plate 430, so that the support portion 411 passes through the avoidance hole 431 and is fixed to the fixed plate 230. Thus, the movable plate 430 is located between the housing 410 and the fixed plate 230 and can move against the elastic force of the spring 440. Refer Figure 1 to Figure 3 .

[0066] Both the housing 410 and the movable plate 430 are annular. After assembly, the brake stator assembly 400 is also annular, so that the brake stator assembly 400 is sleeved on the shaft portion 120, and the movable plate 430 faces the brake disc 300. The brake disc 300 is located between multiple support portions 411, that is, the diameter of the brake disc 300 is smaller than the diameter of the movable plate 430.

[0067] Refer Figure 1 to Figure 3 and the figure. When assembling the brake stator assembly 400, the brake stator assembly 400 is sleeved outside the shaft portion 120, and then the second fastener 500 passes through the sleeve hole 414 and is screwed to the fixed plate 230, so that the brake disc 300 is located between the movable plate 430 and the fixed plate 230. It should be noted that when the brake stator assembly 400 is assembled, the spring 440 is in a compressed state. At this time, there is a gap a between the movable plate 430 and the housing 410.

[0068] refer to Figures 1 to 13 The integrated structure of the axial magnetic field motor and the double friction surface brake can be assembled by the following steps:

[0069] (1) The motor stator assembly 200 is sleeved outside the shaft 120 and is located between the limit platform 121 and the magnetic steel 130, so that the stator core 210 fixes one side of the stator winding 220 and is arranged opposite to the magnetic steel 130, and an air gap a is maintained between the stator core 210 and the magnetic steel 130.

[0070] (2) The brake disc 300 is matched with the limiting groove 310 and the limiting platform 121 to be sleeved outside the shaft portion 120 and located on the side of the motor stator assembly 200 away from the magnetic steel 130 .

[0071] (3) The brake stator assembly 400 is sleeved on the outside of the shaft portion 120, and passes through the sleeve hole 414 on the shell 410 through the second fastener 500 and is fixed on the fixed plate 230. At this time, the spring 400 is in a compressed state, so that the movable plate 430 is pressed against the fixed plate 230 through the brake disc 300 and maintains a certain pressure. At this time, there is a gap a between the movable plate 430 and the shell 410.

[0072] like Figure 14 As shown, the integrated structure of the axial magnetic field motor and the double friction surface brake is in a non-operating mode, wherein the stator winding 220 is not energized, the joint module has no power, and the coil 420 of the brake stator assembly 400 is not energized, and no magnetic field is generated. At this time, the spring 440 is in a compressed state, so that the friction plates 320 on both sides of the brake disc 300 are respectively in contact with the movable plate 430 and the fixed plate 230, and maintain a certain pressure. The friction plates 320 respectively press the movable plate 430 and the fixed plate 230 to generate static friction to prevent the rotor assembly 100 from rotating, maintain the spatial position of the robot arm, and avoid loosening.

[0073] like Figure 15As shown, the integrated structure of the axial magnetic field motor and the double friction surface brake is in the operating mode. Among them, three-phase alternating current is applied to the stator winding 220 to provide power for the joint module. At the same time, direct current is applied to the coil 420 of the brake stator assembly 400, and the magnetic field generated by it forms a loop through the housing 410 and the movable plate 430, sucking the movable plate 430 tightly on the surface of the housing 410 and maintaining a certain pressure. This requires that the suction force of the coil 420 on the movable plate 430 is greater than the thrust force of the spring 440 on the movable plate 430 in order to suck the movable plate 430 tightly on the surface of the housing 410. At this time, the brake disc 300 is located between the fixed plate 230 and the movable plate 430, and there is a gap h between them and it is loose, ensuring that the rotor assembly 100 can rotate smoothly.

[0074] When the integrated structure of the axial magnetic field motor and the double friction surface brake is powered off, the joint module loses power. However, due to inertia, the rotor assembly 100 continues to rotate. The coil 420 of the brake stator assembly 400 is powered off at the same time, and the suction force on the movable plate 430 disappears. At this time, the spring 440 is in a compressed state, pressing the movable plate 430 and the brake disc 300 tightly on the surface of the fixed plate 230 and maintaining a certain pressure. Relying on the frictional force of the friction plate 320, the rotor assembly 100 is braked to prevent the rotor assembly 100 from rotating, maintaining the spatial position of the robotic arm and avoiding loosening, so as to restore to the non-operating state of the integrated structure. Refer to Figure 14 。

[0075] In summary, since the motor stator assembly 200, the brake disc 300 and the brake stator assembly 400 are integrated on the shaft portion 120 of the rotor assembly 100, the axial dimension of the overall structure is further shortened to meet the limited space size of the motor, and the structure is compact. And the fixed plate 230 of the motor stator assembly 200 also serves as the fixed plate that frictions with the brake disc 300, further shortening the circumferential dimension of the motor.

[0076] In addition, those skilled in the art can also change the shapes, structures and materials of the motor stator assembly 200, the brake disc 300 and the brake stator assembly 400 according to the actual situation. As long as on the basis of the above disclosure of the present invention, the same or similar technical solutions as those of the present invention are adopted, the same or similar technical problems as those of the present invention are solved, and the same or similar technical effects as those of the present invention are achieved, they all fall within the protection scope of the present invention. The specific implementation manners of the present invention are not limited thereto.

[0077] That is to say, as long as the same or similar technical solutions as those of the present invention are adopted on the basis of the above disclosure of the present invention, the same or similar technical problems as those of the present invention are solved, and the same or similar technical effects as those of the present invention are achieved, they fall within the protection scope of the present invention. The specific implementation manners of the present invention are not limited thereto.

[0078] In the description of this specification, the description with reference to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms are not necessarily directed to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0079] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the drawings are only examples and do not limit the present invention. The object of the present invention has been fully and effectively achieved. The functions and structural principles of the present invention have been shown and described in the embodiments. Without departing from the above principles, the embodiments of the present invention may have any deformation or modification.

Claims

1. An integrated structure of an axial magnetic field motor and a double friction surface brake, characterized in that, include: The rotor assembly comprises a back iron, a shaft and a plurality of magnetic steels, wherein the back iron is connected to the shaft, and the plurality of magnetic steels are fixed to the back iron and arranged around the shaft; The motor stator assembly comprises a stator core and a stator winding, wherein the stator winding is fixed on the stator core, the stator core is sleeved on the shaft, at least one stopper is provided on the shaft, and the stator core is located between the stopper and the magnetic steel, so that the stator core is fixed to a side of the stator winding and is arranged opposite to the magnetic steel; A brake disc, sleeved on the shaft, the brake disc is located on a side of the motor stator assembly away from the magnetic steel; The brake stator assembly comprises a housing, a coil, a movable plate and at least one spring, wherein the spring is connected between the housing and the movable plate, the coil is fixed to a side of the housing facing the movable plate, and the housing is fixed to a side of the motor stator assembly facing away from the magnetic steel, so that the brake disc can overcome the elastic force of the spring and be located between the movable plate and the motor stator assembly; The limit platform and the magnetic steel are located on the same side of the back iron, and the brake disc is provided with a limit groove that matches the limit platform; The motor stator assembly also includes: a fixing plate, the fixing plate being fixed on the stator core and being located on a side of the stator core away from the stator winding; Friction plates opposite to the movable plate and the fixed plate are respectively fixed on both sides of the brake disc in the axial direction.

2. The integrated structure of the axial magnetic field motor and the double friction surface brake according to claim 1, characterized in that, At least one supporting portion is disposed on the shell, and the shell is connected to the fixing plate via the supporting portion.

3. The integrated structure of the axial magnetic field motor and the double friction surface brake according to claim 2, characterized in that The movable plate is provided with an escape hole for escaping the support part.

4. The integrated structure of the axial magnetic field motor and the double friction surface brake according to claim 1, characterized in that, A coil slot for installing the coil is formed on one side of the shell facing the movable plate.

5. The integrated structure of the axial magnetic field motor and the double friction surface brake according to claim 2, characterized in that, A spring slot for installing the spring is provided on one side of the shell facing the movable plate.

6. The integrated structure of the axial magnetic field motor and the double friction surface brake according to claim 5, characterized in that, A plurality of the support parts are arranged at intervals along the outer periphery of the shell, and a spring groove is provided between two adjacent support parts.

7. The integrated structure of the axial magnetic field motor and the double friction surface brake according to claim 6, characterized in that, A plurality of support portions surround the outside of the brake disc.

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