Motor with non-excitation operation brake

Abstract

A brake unit (3) of a motor (1) with a non-excitation operation brake includes: a friction plate (31) that rotates integrally with the rotating shaft (25) of a motor unit (2); an armature (32); and a braking spring (33) that presses the armature (32) toward the friction plate (31). The brake unit (3) also includes: an electromagnet (34) for attracting the armature (32) in a direction away from the friction plate (31) by energization; and an end plate (35) attached to the end surface (230) of a rotor (23) so as to rotate integrally with the rotor (23) of the motor unit (2). When the electromagnet (34) is in a non-energized state, the brake unit (3) holds the rotation of the rotating shaft (25) in a stationary state by sandwiching the friction plate (31) between the armature (32) and the end plate (35).

Description

Non-excitation brake motor

[0001] The present disclosure relates to a motor with a brake that operates without excitation.

[0002] Patent Document 1 discloses a non-excitation brake that includes a friction plate that rotates integrally with the rotating shaft of a motor, a side plate, an armature, a braking spring, and an electromagnet that attracts the armature away from the friction plate when current is applied.

[0003] In this non-excitation brake, when the electromagnet is not energized, the armature is urged toward the friction plate by the braking spring, and the friction plate is sandwiched between the armature and the side plate, thereby holding the rotating shaft stationary.

[0004] When the electromagnet is energized, the armature is attracted away from the friction plate, thereby releasing the braking force of the non-excitation brake.

[0005] Japanese Patent Application Laid-Open No. 2002-130340

[0006] In the conventional non-excitation brake described above, the friction plate is sandwiched between the armature and the side plate, so space is required to accommodate the side plate, which tends to create dead space, making it difficult to reduce the size of the entire structure.

[0007] The present disclosure provides a motor with a non-excitation operating brake that can be made smaller.

[0008] A non-excitation actuated brake-equipped motor according to one embodiment of the present disclosure includes an inner rotor motor unit and a brake unit configured to hold the motor unit stationary. The motor unit includes a stator, a rotor, and a rotating shaft that rotates integrally with the rotor. The brake unit includes a friction plate that rotates integrally with the rotating shaft, an armature, a braking spring that biases the armature toward the friction plate, an electromagnet that attracts the armature away from the friction plate when energized, and an end plate attached to an end face of the rotor so as to rotate integrally with the rotor. The brake unit is configured to hold the rotating shaft stationary by sandwiching the friction plate between the armature and the end plate when the electromagnet is de-energized.

[0009] A motor with a non-excitation brake according to another aspect of the present disclosure includes an inner rotor motor unit and a brake unit configured to hold the motor unit stationary. The motor unit includes a stator, a rotor, and a rotating shaft that rotates integrally with the rotor. The brake unit includes a friction plate attached to an end face of the rotor so as to rotate integrally with the rotating shaft, an armature, a braking spring that biases the armature toward the friction plate, and an electromagnet that attracts the armature away from the friction plate when energized. The brake unit is configured to hold the rotating shaft stationary by pressing the armature against the friction plate when the electromagnet is de-energized.

[0010] The present disclosure can provide a motor with a non-excitation operating brake that can be made smaller.

[0011] FIG. 1 is a cross-sectional view schematically showing the configuration of a motor with a non-excitation operated brake of a first embodiment. FIG. 2 is a cross-sectional view schematically showing the configuration of a motor with a non-excitation operated brake of a second embodiment. FIG. 3 is a cross-sectional view schematically showing the configuration of a motor with a non-excitation operated brake of a third embodiment. FIG. 4 is a cross-sectional view schematically showing the configuration of a motor with a non-excitation operated brake of a fourth embodiment. FIG. 5 is a cross-sectional view schematically showing the configuration of a motor with a non-excitation operated brake of a fifth embodiment. FIG. 6 is a cross-sectional view schematically showing the configuration of a motor with a non-excitation operated brake of a sixth embodiment. FIG. 7 is a cross-sectional view schematically showing the configuration of a motor with a non-excitation operated brake of a comparative example.

[0012] A motor with a non-excitation operated brake according to an embodiment of the present disclosure will be described in detail below with reference to the drawings. However, the drawings described in the following embodiments are schematic diagrams, and the ratios of the sizes and thicknesses of the components do not necessarily reflect the actual dimensional ratios. Note that the configurations described in the following embodiments are merely examples of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the present disclosure can be achieved.

[0013] 1. First Embodiment A non-excitation operated brake-equipped motor 1 according to a first embodiment will be described with reference to FIG.

[0014] (Outline of a Motor with a Non-Excitation Operated Brake) FIG. 1 is a cross-sectional view showing a schematic configuration of a motor with a non-excitation operated brake 1 according to a first embodiment.

[0015] The motor 1 with a non-excitation operated brake includes a motor section 2 and a brake section 3. The motor 1 with a non-excitation operated brake has an axis 1A.

[0016] In this disclosure, the direction in which the axis 1A extends is referred to as the "axial direction." In the axial direction, the side on which the motor unit 2 is located relative to the brake unit 3 is referred to as the "first direction D1." In the axial direction, the side on which the brake unit 3 is located relative to the motor unit 2 (i.e., the direction opposite to the first direction D1) is referred to as the "second direction D2."

[0017] The motor unit 2 is configured to generate rotation based on the supply of electric power, and the brake unit 3 is configured to hold the rotation of the motor unit 2 in a stationary state based on the supply of electric power.

[0018] In the non-excitation operated brake-equipped motor 1, the motor section 2 and the brake section 3 are integrated into a compact body as will be described later.

[0019] (Motor Section) The following describes the detailed structure of the motor section 2. The motor section 2 is an inner rotor type motor.

[0020] The motor section 2 includes an annular stator 21, a rotor 23 arranged inside the stator 21 in the radial direction of the motor section 2, and a rotating shaft 25 connected to the rotor 23 so as to rotate integrally with the rotor 23.

[0021] The stator 21 includes an annular stator core 212 and a plurality of coil wires 214 wound around the stator core 212 .

[0022] The axis of the cylindrical stator core 212 coincides with the axis 1A of the motor 1 with a non-excitation operated brake. The stator core 212 is formed by stacking a plurality of steel plates 218 in the thickness direction. Each steel plate 218 is made of a magnetic material. Each steel plate 218 is, for example, a silicon steel plate.

[0023] The coil wire 214 is, for example, an enameled wire. A current is supplied to the coil wire 214 by a circuit board (not shown).

[0024] The rotor 23 rotates around the axis of the rotating shaft 25 relative to the stator 21. That is, magnetic flux generated from the multiple coil wires 214 wound around the stator core 212 generates an electromagnetic force that rotates the rotor 23 around the axis of the rotating shaft 25. The axis of the cylindrical rotating shaft 25 coincides with the axis 1A of the motor 1 with a non-excitation operated brake.

[0025] The rotor 23 is disposed inside the stator core 212. The rotor 23 includes a rotor core 232 and a plurality of permanent magnets 234.

[0026] The rotor core 232 is formed by stacking a plurality of steel plates 238 in the thickness direction. Each steel plate 238 is made of a magnetic material. Each steel plate 238 is, for example, a silicon steel plate.

[0027] The rotor core 232 is formed in a cylindrical shape concentric with the stator core 212. The axis of the rotor core 232 coincides with the axis of the rotating shaft 25. In the axial direction, the positions of both ends of the rotor core 232 are substantially aligned with the positions of both ends of the stator core 212.

[0028] The rotor core 232 is provided with a plurality of magnet accommodating portions 233. The plurality of magnet accommodating portions 233 accommodate a plurality of permanent magnets 234. Each of the plurality of magnet accommodating portions 233 is a through hole that passes through the rotor core 232 in the axial direction.

[0029] Each of the multiple permanent magnets 234 is held in the magnet accommodating portion 233 by being inserted into the magnet accommodating portion 233 with, for example, an adhesive attached thereto.

[0030] The plurality of magnet housing portions 233 are provided at equal intervals in the circumferential direction of the rotor core 232. As a result, the plurality of permanent magnets 234 are arranged at equal intervals in the circumferential direction of the rotor core 232.

[0031] The rotating shaft 25 is held inside the cylindrical rotor core 232. The rotating shaft 25 is connected to the rotor core 232 so as to rotate integrally with the rotor core 232 about the axis 1A.

[0032] (Brake Unit) The following describes the detailed structure of the brake unit 3. The brake unit 3 is configured to hold the rotation of the motor unit 2 stationary only when not energized.

[0033] The brake portion 3 includes a friction plate 31, an armature 32, a braking spring 33, an electromagnet 34, and an end plate 35. As shown in Fig. 1, the armature 32 and the friction plate 31 are located between the electromagnet 34 and the end plate 35 in the axial direction.

[0034] The friction plate 31 is a brake disc having an annular shape, and is connected to the rotary shaft 25 of the motor unit 2 so as to rotate integrally with the rotary shaft 25.

[0035] The armature 32 is an annular plate-shaped member made of a magnetic material. The orientation of the armature 32 relative to the friction plate 31 is the second orientation D2. The armature 32 is movable in parallel to the axial direction, but movement in other directions is restricted.

[0036] The brake spring 33 is a coil spring. The brake spring 33 is disposed on the electromagnet 34 so as to constantly urge the armature 32 toward the friction plate 31. The orientation of the brake spring 33 relative to the armature 32 is the second orientation D2. The brake spring 33 is configured to constantly urge the armature 32 in the first orientation D1.

[0037] The electromagnet 34 is configured to attract the armature 32 in a direction away from the friction plate 31 when energized. The orientation of the electromagnet 34 relative to the armature 32 is the second orientation D2. The electromagnet 34 is configured to attract the armature 32 in the second orientation D2 when in an excited state.

[0038] The electromagnet 34 includes a core 5 containing a magnetic material and an excitation coil 6 wound around the core 5. The core 5 is provided with a coil accommodating portion 53 for accommodating the excitation coil 6 and a spring accommodating portion 56 for accommodating the brake spring 33. The spring accommodating portion 56 is a blind hole that opens in the first direction D1. The brake spring 33 is accommodated in the spring accommodating portion 56 in a compressed state. A first end of the brake spring 33 is in pressure contact with the bottom surface of the spring accommodating portion 56, and a second end of the brake spring 33 is in pressure contact with the surface of the armature 32 facing the second direction D2.

[0039] In the radial direction of the core 5, the spring accommodating portion 56 is provided at a position outside the coil accommodating portion 53. Therefore, in the radial direction of the motor 1 with a non-excitation operated brake, the excitation coil 6 is located between the brake spring 33 and the rotating shaft 25. The radial direction here is a direction perpendicular to the axial direction.

[0040] The end plate 35 is an annular plate-shaped member attached to the end surface 230 of the rotor 23 so as to rotate integrally with the rotor 23. The orientation of the end surface 230 of the rotor 23 is perpendicular to the radial direction of the rotor 23, more specifically, the second orientation D2. The end plate 35 is fixed to the rotor 23, for example, via an adhesive, but the means for attaching the end plate 35 to the rotor 23 is not particularly limited as long as the end plate 35 rotates integrally with the rotor 23.

[0041] The end plate 35 attached to the rotor 23 is located radially inward of the stator 21 of the motor unit 2. The end plate 35 is located axially within the range of the stator 21. In other words, the end plate 35 is located so as not to extend beyond the range of the stator 21 in the axial direction.

[0042] Furthermore, the end plate 35 attached to the rotor 23 is located within the range in the radial direction of the motor unit 2 where the rotor 23 is present. It is preferable that the end plate 35 is located within the range in the radial direction of the motor unit 2 where the rotor 23 is present without protruding outside.

[0043] The end plate 35 is a metal member. The metal used for the end plate 35 is, for example, iron or stainless steel. In this disclosure, iron is used to include iron alloys. Examples of iron alloys include silicon steel, permalloy, and ferrite. The surface of the end plate 35 is preferably plated. The plating is, for example, zinc plating.

[0044] In the motor 1 with a non-excitation operating brake, the brake unit 3 further includes a hub 36 .

[0045] The hub 36 is an annular member fixed to the rotating shaft 25 of the motor unit 2 so as to rotate integrally with the rotating shaft 25. The friction plate 31 has splines that mate with the hub 36. The friction plate 31 is connected to the hub 36 so as to rotate integrally with the hub 36 and is capable of axial translation relative to the hub 36. That is, the friction plate 31 is connected to the rotating shaft 25 of the motor unit 2 via the hub 36. In the motor 1 with a non-excitation activated brake, the friction plate 31 has a portion that engages with the hub 36, and in order to prevent damage to this portion, a reinforcing plate 315 is provided on the friction plate 31. The reinforcing plate 315 is preferably embedded inside the friction plate 31. Note that, although it is preferable to provide the reinforcing plate 315 in the motor 1 with a non-excitation activated brake, the reinforcing plate 315 is not necessarily provided.

[0046] Furthermore, the brake unit 3 includes a housing 39 that forms the outer shell of the brake unit 3 .

[0047] In the motor 1 with a non-excitation operating brake, the housing 39 of the brake section 3 is constructed separately from the housing 29 that forms the outer shell of the motor section 2.

[0048] In other words, the housing 39 of the brake unit 3 is formed by a part 43 of the housing 4 that forms the outer shell of the non-excitation operated brake-equipped motor 1. The housing 29 of the motor unit 2 is formed by another part 42 of the housing 4. The orientation in which the other part 42 of the housing 4 is positioned relative to the part 43 of the housing 4 is the first orientation D1.

[0049] The housing 4 (i.e., housings 29, 39) is a cylindrical member made of a non-magnetic material. The non-magnetic material here is, for example, aluminum, but the housing 4 can also be made of other non-magnetic materials such as stainless steel. That is, in the motor 1 with a non-excitation brake, the housing 39 of the brake unit 3 is made of a non-magnetic material such as aluminum, and the housing 29 of the motor unit 2 is made of a non-magnetic material such as aluminum. In this disclosure, aluminum is used to include aluminum alloys.

[0050] In the motor 1 with a non-excitation brake, when the brake section 3 is de-energized, the braking spring 33 applies a biasing force to the armature 32 in a first direction D1, which presses the armature 32 against the friction plate 31. Therefore, when the brake section 3 is de-energized, the friction plate 31 is sandwiched between the armature 32 and the end plate 35, and the rotating shaft 25 of the motor section 2 is held stationary.

[0051] The brake portion 3 in the de-energized state is the brake portion 3 in which the electromagnet 34 is in a de-energized state, in other words, the brake portion 3 in a non-excited state.

[0052] In the motor 1 with a non-excitation brake, in the brake section 3 when power is applied, the magnetic attractive force generated by the electromagnet 34 causes the armature 32 to move in the second direction D2 against the biasing force of the brake spring 33, and move away from the friction plate 31. Therefore, in the brake section 3 when power is applied, the friction plate 31 is not sandwiched between the armature 32 and the end plate 35, and the braking of the rotating shaft 25 of the motor section 2 is released.

[0053] The brake portion 3 when energized is the brake portion 3 in which the electromagnet 34 is in an energized state, in other words, the brake portion 3 in an excited state.

[0054] (Operation and Effect) According to the motor with a non-excitation operated brake 1 of the first embodiment, as shown in Figure 1, the motor section 2 and the brake section 3 are integrated into a compact unit. In other words, with the motor with a non-excitation operated brake 1, there is no need to arrange a side plate inside the motor with a non-excitation operated brake 1 as in the prior art described above, and dead space is less likely to occur. As a result, the overall structure of the motor with a non-excitation operated brake 1 can be made more compact.

[0055] 7 is a cross-sectional view showing the schematic configuration of a comparative example of a motor with a non-excitation operated brake 1000. In the comparative example of the motor with a non-excitation operated brake 1000, a side plate 9 is disposed inside the motor with a non-excitation operated brake 1000. In the comparative example of the motor with a non-excitation operated brake 1000, the friction plate 31 is sandwiched between the armature 32 and the side plate 9 located away from the motor section 2, thereby holding the rotating shaft 25 of the motor section 2 stationary.

[0056] Therefore, in the comparative example of the non-excitation operated brake motor 1000, the motor section 2 and the brake section 3000 including the side plate 9 are separated in the axial direction, which tends to create dead space, making it difficult to reduce the size of the entire structure.

[0057] In contrast to this, the motor with a non-excitation operated brake 1 of the first embodiment allows for a reduction in size of the overall structure, particularly in the axial direction.

[0058] 2. Second Embodiment A non-excitation operated brake-equipped motor 1b according to a second embodiment will be described with reference to Fig. 2. In the following description, the same components as those in the first embodiment will be designated by the same reference numerals and detailed description thereof will be omitted.

[0059] 2 is a cross-sectional view schematically illustrating a non-excitation operated brake-equipped motor 1b according to the second embodiment. As shown in FIG. 2, in the non-excitation operated brake-equipped motor 1b, the friction plate 31b of the second embodiment differs from the friction plate 31 of the first embodiment in that, instead of being connected to the rotating shaft 25 of the motor unit 2 as in the first embodiment, the friction plate 31b is connected to a surface 350 of an end plate 35 fixed to the rotor 23 so as to rotate integrally with the motor unit 2. The surface 350 of the end plate 35 faces in a direction perpendicular to the radial direction of the brake unit 3b of the second embodiment, more specifically, in a second direction D2.

[0060] In the non-excitation brake-equipped motor 1b, the brake unit 3b differs from the brake unit 3 of the first embodiment in that it does not include a hub 36. The friction plate 31b is fixed to the end plate 35, for example, via an adhesive, but the means for attaching the friction plate 31b to the end plate 35 is not limited as long as the end plate 35 and the friction plate 31b rotate integrally.

[0061] The friction plate 31b attached to the end plate 35 is located radially inward of the stator 21 in the motor unit 2. An end surface 312 of the friction plate 31b facing the second direction D2 is shifted in the axial direction from the stator 21 in the second direction D2.

[0062] The motor 1b with a non-excitation operating brake differs from the friction plate 31 of the first embodiment in that the friction plate 31b is not provided with the reinforcing plate 315 as in the first embodiment. In the motor 1b with a non-excitation operating brake, the friction plate 31b does not have a fitting portion with the hub 36, so the reinforcing plate 315 to prevent damage at the fitting portion is not necessary. Note that it is also possible to provide the friction plate 31b with the reinforcing plate 315 in the motor 1b with a non-excitation operating brake.

[0063] In the non-excitation brake-equipped motor 1b, when the brake section 3b is not energized, the armature 32 is pressed against the end face 312 of the friction plate 31b by the biasing force of the braking spring 33. As a result, the friction plate 31b is sandwiched between the armature 32 and the end plate 35, and the rotating shaft 25 of the motor section 2 is held stationary.

[0064] When the brake portion 3b is energized, the armature 32 moves away from the friction plate 31b due to the magnetic attraction force generated by the electromagnet 34, and the braking of the rotary shaft 25 of the motor portion 2 is released.

[0065] According to the second embodiment of the motor with a non-excitation operated brake 1b, the motor section 2 and the brake section 3b are integrated into a more compact structure, as shown in Figure 2. In other words, the motor with a non-excitation operated brake 1b does not require the placement of a side plate inside the motor with a non-excitation operated brake 1b as in the prior art, and it also does not require the placement of a hub 36. This allows for a further reduction in the size of the entire structure of the motor with a non-excitation operated brake 1b.

[0066] Furthermore, in the motor 1b with a non-excitation operated brake of the second embodiment, the friction plate 31b does not have a reinforcing plate 315, which further reduces the overall size of the motor 1 with a non-excitation operated brake. In addition, the friction plate 31b does not have a portion that fits with the hub 36, which makes the motor 1b with a non-excitation operated brake quieter. The friction plate 31b is fixed to the end plate 35, which reduces the occurrence of idling friction between the friction plate 31b and the end plate 35.

[0067] 3. Third Embodiment A non-excitation operated brake-equipped motor 1c according to a third embodiment will be described with reference to Fig. 3. In the following description, the same components as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

[0068] 3 is a cross-sectional view showing a motor 1c with a non-excitation operated brake according to a third embodiment. As shown in FIG. 3, in the motor 1c with a non-excitation operated brake, a friction plate 31c of the third embodiment is not connected to the rotating shaft 25 of the motor section 2 as in the first embodiment, but is connected to an end surface 230 of the rotor 23 of the motor section 2 so as to rotate integrally with the end surface 230. In this respect, the friction plate 31c of the third embodiment differs from the friction plate 31 of the first embodiment.

[0069] In the non-excitation operated brake-equipped motor 1c, a brake section 3c of the third embodiment differs from the brake section 3 of the first embodiment in that it does not include a hub 36. The friction plates 31c are fixed to the rotor 23, for example, via an adhesive, but the means for attaching the friction plates 31c to the rotor 23 is not limited as long as they rotate integrally with the rotor 23.

[0070] The friction plate 31c attached to the rotor 23 is located radially inward of the stator 21 in the motor section 2. An end surface 312 of the friction plate 31c facing the second direction D2 is shifted in the axial direction from the stator 21 in the second direction D2.

[0071] In the motor 1c with a non-excitation operating brake, the friction plates 31c of the third embodiment differ from the friction plates 31 of the first embodiment in that the friction plates 31c are not provided with the reinforcing plates 315 as in the first embodiment. In the motor 1c with a non-excitation operating brake, the friction plates 31c do not have a fitting portion with the hub 36, so the reinforcing plates 315 for preventing damage at the fitting portion are not necessary. Note that in the motor 1c with a non-excitation operating brake, it is also possible to provide the friction plates 31c with the reinforcing plates 315.

[0072] In the non-excitation brake-equipped motor 1c, when the brake section 3c is not energized, the armature 32 is pressed against the end surface 312 of the friction plate 31c by the biasing force of the braking spring 33. As a result, the rotating shaft 25 of the motor section 2 is held stationary.

[0073] When the brake portion 3c is energized, the armature 32 moves away from the friction plate 31c due to the magnetic attraction force generated by the electromagnet 34, and the braking of the rotary shaft 25 of the motor portion 2 is released.

[0074] According to the non-excitation operated brake motor 1c of the third embodiment, as shown in Figure 3, the motor section 2 and the brake section 3c are integrated into an even more compact structure. That is, the non-excitation operated brake motor 1c does not require a side plate to be disposed inside the non-excitation operated brake motor 1c as in the prior art, and does not require a hub 36. This allows for a further reduction in the size of the entire structure of the non-excitation operated brake motor 1c.

[0075] In the non-excitation operated brake equipped motor 1c of the third embodiment, the friction plate 31c does not have a portion that fits with the hub 36, so that the non-excitation operated brake equipped motor 1c is made quieter.

[0076] 4. Fourth Embodiment A non-excitation operated brake-equipped motor 1d according to a fourth embodiment will be described with reference to Fig. 4. In the following description, the same components as those in the first embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

[0077] FIG. 4 is a cross-sectional view schematically illustrating a motor 1d with a non-excitation operation brake according to a fourth embodiment. As shown in FIG. 4, in the motor 1d with a non-excitation operation brake, a housing 39d of a brake unit 3d according to the fourth embodiment includes a magnetic material. The magnetic material here is, for example, iron. That is, the housing 39d of the brake unit 3d is formed of a magnetic material. The housing 39d is preferably made of iron. That is, the housing 39d of the fifth embodiment is different from the housing 39 of the first embodiment in that it is formed of a magnetic material such as iron, whereas the housing 39d of the fifth embodiment is formed of a non-magnetic material such as aluminum.

[0078] The core 5 and the excitation coil 6 that constitute the electromagnet 34 are located inside the housing 39d in the radial direction of the brake portion 3d.

[0079] The core 5 and the excitation coil 6 are located within the range of the housing 39d in the axial direction. In other words, the core 5 and the excitation coil 6 are located in positions that do not extend beyond the range of the housing 39d in the axial direction.

[0080] In the non-excitation brake-equipped motor 1d, the housing 29 of the motor section 2 is made of a non-magnetic material such as aluminum.

[0081] In the non-excitation operating brake-equipped motor 1d, an iron housing 39d is different from the housing 39 of the first embodiment in that it is in close contact with the core 5 of the electromagnet 34.

[0082] The housing 39d has an inner peripheral surface 390 that faces inward in the radial direction of the brake portion 3d. The core 5 of the electromagnet 34 has an outer peripheral surface 50 that faces outward in the radial direction of the brake portion 3d. The inner peripheral surface 390 of the housing 39d is in close contact with the outer peripheral surface 50 of the core 5. The entire outer peripheral surface 50 of the core 5 may be in close contact with the housing 39d, or only a portion of the outer peripheral surface 50 of the core 5 may be in close contact with the housing 39d.

[0083] In the motor 1d with a non-excitation operated brake of the fourth embodiment, the core 5 including a magnetic body and the housing 39d including a magnetic body are combined to form a magnetic circuit. In other words, the housing 39d located radially outward of the core 5 functions as part of the magnetic circuit, which makes it possible to reduce the size of the core 5.

[0084] In particular, the overall size in the axial direction can be reduced by shortening the axial dimension of the core 5. By shortening the axial dimension of the core 5 and lengthening the radial dimension of the core 5, it is possible to wind the same number of excitation coils 6 around the core 5 as in the first embodiment.

[0085] In the motor 1d with a non-excitation operated brake according to the fourth embodiment, the magnetic material constituting the housing 39d and the magnetic material constituting the core 5 are both iron, but this is not limitative. The magnetic material constituting the housing 39d and the magnetic material constituting the core 5 may be the same or different.

[0086] 5. Fifth Embodiment A non-excitation operated brake-equipped motor 1e according to a fifth embodiment will be described with reference to Fig. 5. In the following description, the same components as those in the fourth embodiment will be denoted by the same reference numerals, and detailed description thereof will be omitted.

[0087] Fig. 5 is a cross-sectional view schematically showing a motor 1e with a non-excitation operation brake according to a fifth embodiment. As shown in Fig. 5, in the motor 1e with a non-excitation operation brake, a housing 39d of the fifth embodiment that forms the outer shell of the brake unit 3 and a core 5 of the electromagnet 34 of the fifth embodiment are configured as an integrated part 7 containing a magnetic material. That is, the housing 39d and the core 5 of the fifth embodiment differ from the housing 39d and the core 5 of the fourth embodiment in that, while the housing 39d and the core 5 of the fourth embodiment are formed separately, the housing 39d and the core 5 of the fifth embodiment are formed as an integrated part.

[0088] The radially outer portion 71 of the integral body 7 that constitutes the housing 39d and the radially inner portion 72 of the integral body 7 that constitutes the core 5 both contain a magnetic material. In other words, the integral body 7 is formed of a magnetic material. The integral body 7 is preferably made of, for example, iron.

[0089] In the motor with a non-excitation operated brake 1e of the fifth embodiment, the magnetic circuit is formed by the one-piece member 7 including the housing 39d and the core 5. Therefore, the dimension of the brake portion 3e of the fifth embodiment can be shortened in the axial direction, thereby making it possible to reduce the size of the entire structure.

[0090] 6. Sixth Embodiment A motor 1f with a non-excitation operation brake according to a sixth embodiment will be described with reference to Fig. 6. In the following description, the same components as those in the fourth embodiment will be designated by the same reference numerals and detailed description thereof will be omitted.

[0091] 6 is a cross-sectional view showing a motor with a non-excitation operation brake if according to a sixth embodiment. As shown in FIG. 6, in the motor with a non-excitation operation brake if, a housing 39d according to the sixth embodiment, which forms the outer shell of the brake unit 3d according to the sixth embodiment, and the core 5 of the electromagnet 34 according to the sixth embodiment are positioned with a small gap 8 between them.

[0092] That is, the housing 39d of the sixth embodiment differs from the housing 39d of the fourth embodiment in that, while in the fourth embodiment the housing 39d is in close contact with the core 5, the housing 39d including the magnetic material is positioned between the housing 39d and the core 5 including the magnetic material via a gap 8. An inner peripheral surface 390 of the housing 39d of the sixth embodiment and an outer peripheral surface 50 of the core 5 of the sixth embodiment face each other via the gap 8.

[0093] In the sixth embodiment of the motor 1f with a non-excitation operated brake, the housing 39d located radially outside the core 5 also functions as part of the magnetic circuit, making it possible to reduce the size of the core 5, particularly in the axial direction.

[0094] The radial dimension of the gap 8 of the brake portion 3d of the sixth embodiment can be set to any appropriate dimension as long as a magnetic circuit can be formed by the core 5 and the housing 39d.

[0095] 7. Modifications The above embodiment is merely one of various embodiments of the present disclosure. In the following description of the modification, the same components as those in the above embodiment will be denoted by the same reference numerals and detailed description thereof will be omitted.

[0096] In the above embodiment, the end plate 35 is made of metal, but the end plate 35 may also be made of resin. Also, in the above embodiment, the surface of the end plate 35 is plated, but the end plate 35 does not have to be plated. In other words, the end plate 35 may be a plated resin plate material, or an unplated resin plate material. The end plate 35 may also be an unplated metal plate material.

[0097] In the motors 1d, 1e, and 1f with a non-excitation operated brake according to the fourth, fifth, and sixth embodiments, the friction plates 31 are connected to the rotating shaft 25 via the hub 36, as in the first embodiment, but the connection structure of the friction plates 31 is not limited to this. That is, in the motors 1d, 1e, and 1f with a non-excitation operated brake according to the fourth, fifth, and sixth embodiments, the friction plates 31 may be fixed to the end plates 35, as in the second embodiment. Furthermore, in the motors 1d, 1e, and 1f with a non-excitation operated brake according to the fourth, fifth, and sixth embodiments, the friction plates 31 may be fixed to the end faces 230 of the rotor 23, as in the third embodiment.

[0098] In other configurations of the above-described embodiments, various modifications can be made depending on the design, etc., as long as the object of the present disclosure can be achieved.

[0099] 8. Summary As described based on the above embodiment and modified examples, the non-excitation operated brake-equipped motor (1, 1b) according to the first aspect of the present disclosure includes an inner rotor type motor section (2) and a brake section (3, 3b) configured to hold the motor section (2) stationary. The motor section (2) includes a stator (21), a rotor (23), and a rotating shaft (25) that rotates integrally with the rotor (23). The brake section (3, 3b) includes a friction plate (31, 31b) that rotates integrally with the rotating shaft (25), an armature (32), and a braking spring (33) that biases the armature (32) toward the friction plate (31, 31b). The brake unit (3, 3b) also includes an electromagnet (34) that attracts the armature (32) in a direction away from the friction plate (31, 31b) when energized, and an end plate (35) attached to the end surface (230) of the rotor (23) so as to rotate integrally with the rotor (23). When the electromagnet (34) is in a non-energized state, the brake unit (3, 3b) is configured to hold the rotation of the rotating shaft (25) stationary by sandwiching the friction plate (31, 31b) between the armature (32) and the end plate (35).

[0100] According to this aspect, there is no need to place a side plate inside the motor (1, 1b) as in the prior art, and the motor section (2) and the brake section (3, 3b) are integrated into a compact unit, which allows the motor (1, 1b) to be made smaller, particularly in the axial direction.

[0101] In the motor (1) with a non-excitation operating brake according to the second aspect of the present disclosure, in the first aspect, the friction plate (31) is connected to the rotating shaft (25) via a hub (36).

[0102] According to this aspect, the friction plate (31) can be connected to the rotary shaft (25) via the hub (36) so as to be movable in the axial direction.

[0103] In the non-excitation operated brake-equipped motor (1b) according to the third aspect of the present disclosure, in the first aspect, the friction plate (31b) is connected to the end plate (35).

[0104] According to this embodiment, there is no need to provide a hub (36) between the friction plate (31b) and the rotating shaft (25) for connecting the friction plate (31b) to the rotating shaft (25). Therefore, the motor section (2) and the brake section (3b) are integrated more compactly. In addition, because the friction plate (31b) is not connected to the hub (36), the motor with a non-excitation brake (1b) is quieter.

[0105] A non-excitation operated brake-equipped motor (1c) according to a fourth aspect of the present disclosure includes an inner rotor type motor section (2) and a brake section (3c) configured to hold the motor section (2) stationary. The motor section (2) includes a stator (21), a rotor (23), and a rotating shaft (25) that rotates integrally with the rotor (23). The brake section (3c) includes a friction plate (31c) attached to an end face (230) of the rotor (23) so as to rotate integrally with the rotating shaft (25), and an armature (32). The brake section (3c) also includes a braking spring (33) that biases the armature (32) toward the friction plate (31c), and an electromagnet (34) that attracts the armature (32) away from the friction plate (31c) when energized. The brake portion (3c) is configured to hold the rotation of the rotating shaft (25) stationary by pressing the armature (32) against the friction plate (31c) when the electromagnet (34) is in a non-energized state.

[0106] According to this aspect, there is no need to place a side plate inside the motor (1c) as in the prior art, and the motor section (2) and the brake section (3c) are integrated into a compact body, which allows the motor (1c) to be made smaller, particularly in the axial direction.

[0107] In a motor (1d) with a non-excitation operated brake according to a fifth aspect of the present disclosure, in any one of the first to fourth aspects, the brake unit (3d) further includes a housing (39d) forming an outer shell of the brake unit (3d). The housing (39d) includes a magnetic body.

[0108] According to this aspect, the housing (39d) containing the magnetic material can function as a part of the magnetic circuit of the electromagnet (34), so that the electromagnet (34) can be made smaller.

[0109] In a motor (1d) with a non-excitation operated brake according to a sixth aspect of the present disclosure, in the fifth aspect, the electromagnet (34) includes a core (5) and an excitation coil (6) wound around the core (5). The housing (39d) is positioned in close contact with the core (5).

[0110] According to this aspect, the magnetic circuit is formed by combining the core (5) of the electromagnet (34) and the housing (39d) containing the magnetic material, so that the core (5) can be made smaller.

[0111] In a motor (1e) with a non-excitation operated brake according to a seventh aspect of the present disclosure, in the fifth aspect, the electromagnet (34) includes a core (5) and an excitation coil (6) wound around the core (5). The housing (39d) and the core (5) are configured as a single unit (7) including a magnetic body.

[0112] According to this aspect, the part (71) of the integrated body (7) that constitutes the housing (39d) can constitute part of the magnetic circuit, so that the part (72) of the integrated body (7) that constitutes the core (5) can be made smaller.

[0113] In a motor (1f) with a non-excitation operated brake according to an eighth aspect of the present disclosure, in the fifth aspect, the electromagnet (34) includes a core (5) and an excitation coil (6) wound around the core (5). The housing (39d) is located between the core (5) and the housing (39d) with a gap (8) interposed therebetween.

[0114] According to this aspect, the magnetic circuit is formed by combining the core (5) of the electromagnet (34) and the housing (39d) containing the magnetic material, so that the core (5) can be made smaller.

[0115] REFERENCE SIGNS LIST 1 Motor with non-excitation operating brake 2 Motor section 23 Rotor 230 End face 25 Rotating shaft 3 Brake section 31 Friction plate 32 Armature 33 Brake spring 34 Electromagnet 35 End plate 36 Hub 39 Housing 5 Core 6 Excitation coil 7 Integrated part 8 Air gap

Claims

1. A motor with a non-excitation operating brake, comprising: an inner rotor type motor section; and a brake section configured to hold the rotation of the motor section stationary, wherein the motor section includes a stator, a rotor, and a rotating shaft which rotates integrally with the rotor, and the brake section includes a friction plate which rotates integrally with the rotating shaft, an armature, a braking spring which urges the armature towards the friction plate, an electromagnet which attracts the armature in a direction away from the friction plate when current is applied, and an end plate attached to an end face of the rotor so as to rotate integrally with the rotor, and wherein the brake section is configured to hold the rotation of the rotating shaft stationary by sandwiching the friction plate between the armature and the end plate when the electromagnet is in a non-current-applied state.

2. A motor with a non-excitation operating brake as claimed in claim 1, wherein the friction plate is connected to the rotating shaft via a hub.

3. A non-excitation operating brake-equipped motor according to claim 1, wherein the friction plates are connected to the end plates.

4. A motor with a non-excitation operating brake, comprising: an inner rotor type motor section; and a brake section configured to hold the rotation of the motor section stationary, wherein the motor section includes a stator, a rotor, and a rotating shaft which rotates integrally with the rotor, and the brake section includes a friction plate attached to an end face of the rotor so as to rotate integrally with the rotating shaft, an armature, a braking spring which urges the armature towards the friction plate, and an electromagnet which attracts the armature in a direction away from the friction plate when current is applied, and the brake section is configured to hold the rotation of the rotating shaft stationary by pressing the armature against the friction plate when the electromagnet is not current-carrying.

5. A motor with a non-excitation operating brake as described in any one of claims 1 to 4, wherein the brake unit further includes a housing forming an outer shell of the brake unit, and the housing includes a magnetic material.

6. A motor with a non-excitation operating brake as claimed in claim 5, wherein the electromagnet includes a core and an excitation coil wound around the core, and the housing is positioned in close contact with the core.

7. A motor with a non-excitation operating brake as described in claim 5, wherein the electromagnet includes a core and an excitation coil wound around the core, and the housing and the core are configured as a single unit containing the magnetic material.

8. A motor with a non-excitation operating brake as claimed in claim 5, wherein the electromagnet includes a core and an excitation coil wound around the core, and the housing is located between the core and the housing with a gap therebetween.

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