Radial gap type motor

Abstract

To provide a radial gap type motor capable of reducing a dimension of the radial gap type motor in an axial direction.SOLUTION: A radial gap type motor comprises a rotary shaft 1, a rotor 2 which is fixed to the rotary shaft 1, a stator 3 which is provided outside in a radial direction D2 with respect to the rotor 2, a case 4 to which the stator 3 is fixed, and a bearing 5 which is provided over the rotary shaft 1 and the case 4. The bearing 5 is disposed in such a manner that at least a part of the bearing 5 overlaps the rotor 2 in a view in the radial direction D2.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a radial gap motor. [Background technology]

[0002] Conventionally, a radial gap motor has been known that includes a rotating shaft, a rotor, a stator, a case, and a pair of bearings. The rotating shaft is rotatably supported by the case via the pair of bearings. The rotor is fixed to the rotating shaft. The stator is provided radially outward of the rotor. The stator is fixed to the case (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-161964 Summary of the Invention [Problem to be solved by the invention]

[0004] The rotor is disposed between a pair of bearings in the axial direction. However, in the configuration of the radial gap motor described in Patent Document 1, one of the pair of bearings is disposed away from the rotor on one side in the axial direction, and the other bearing is disposed away from the rotor on the other side in the axial direction. This poses a problem in that the radial gap motor is large in size in the axial direction.

[0005] The present invention has been made to solve the above-mentioned problems, and its object is to provide a radial gap motor that can reduce the dimensions of the radial gap motor in the axial direction. [Means for solving the problem]

[0006] The radial gap motor of this invention comprises a rotating shaft, a rotor fixed to the rotating shaft, a stator arranged radially outward from the rotor, a case to which the stator is fixed, and a bearing arranged across the rotating shaft and the case, and the bearing is arranged so that at least a portion of the bearing overlaps the rotor when viewed radially. In the radial gap motor according to the present invention, a rotating shaft groove into which a bearing is inserted is formed on the axial surface of the rotating shaft. In the radial gap motor according to the present invention, the rotating shaft groove is disposed in the radially middle portion of the rotating shaft. In the radial gap motor according to the present invention, rotor grooves into which bearings are inserted are formed on the axial surface of the rotor. In the radial gap motor according to the present invention, the rotor grooves are arranged on the radially inner portion of the rotor. In the radial gap motor of this invention, the case has a lid arranged adjacent to the rotor in the axial direction, and the lid includes a lid main body facing the rotor in the axial direction and an arm extending from the lid main body in the axial direction toward the rotor, the arm being arranged so that at least a portion of the arm overlaps the rotor when viewed radially, and a bearing is arranged radially between the arm and the rotating shaft. [Effects of the Invention]

[0007] According to the radial gap motor of the present invention, the dimensions of the radial gap motor in the axial direction can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a cross-sectional view showing a radial gap motor according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing a main part of the radial gap motor of FIG. [Figure 3] FIG. 2 is a perspective view showing a main part of the radial gap motor of FIG. [Figure 4] 4 is a perspective view of the main part of the radial gap motor of FIG. 3, seen from the opposite axial direction. [Figure 5] FIG. 10 is a cross-sectional view showing a main part of a radial gap motor according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiment 1 1 is a cross-sectional view showing a radial gap motor according to embodiment 1. The radial gap motor includes a rotating shaft 1, a rotor 2, a stator 3, a case 4, a pair of bearings 5, a rotation detection device 6, and a brake device 7.

[0010] The direction along the axis of the rotating shaft 1 is defined as the axial direction D1. The direction along the radius of a circle centered on the axis of the rotating shaft 1 in a plane perpendicular to the axis of the rotating shaft 1 is defined as the radial direction D2. The direction along the circumference of a circle centered on the axis of the rotating shaft 1 in a plane perpendicular to the axis of the rotating shaft 1 is defined as the circumferential direction D3.

[0011] The rotating shaft 1 includes a cylindrical portion 11 and a flange portion 12. The cylindrical portion 11 has a cylindrical shape. The cylindrical portion 11 is disposed so as to extend in the axial direction D1. The flange portion 12 is provided at an intermediate portion of the cylindrical portion 11 in the axial direction D1. The flange portion 12 is disposed so as to protrude outward in the radial direction D2 from the outer circumferential surface of the cylindrical portion 11.

[0012] A rotary shaft groove 13 is formed on each of the two surfaces of the flange portion 12 of the rotating shaft 1 facing the axial direction D1. Each rotary shaft groove 13 is arranged on the surface of the flange portion 12 facing the axial direction D1 so as to be recessed inward in the axial direction D1. Each rotary shaft groove 13 is arranged in a portion of the flange portion 12 excluding the outer end portion in the radial direction D2. In other words, each rotary shaft groove 13 is arranged in a middle portion of the rotating shaft 1 in the radial direction D2. Furthermore, each rotary shaft groove 13 is arranged over the entire area of the flange portion 12 in the circumferential direction D3.

[0013] The rotor 2 is fixed to the rotating shaft 1. Specifically, the rotor 2 is fixed to a surface of the flange portion 12 facing outward in the radial direction D2. Each rotating shaft groove 13 is disposed at a position overlapping the rotor 2 when viewed along the radial direction D2.

[0014] The rotor 2 includes a rotor core 21 and a plurality of permanent magnets 22. The rotor core 21 is made of a plurality of steel plates stacked in the axial direction D1. A plurality of magnet insertion holes 23 are formed in the rotor core 21. The plurality of magnet insertion holes 23 are arranged in a line in the circumferential direction D3. Each of the magnet insertion holes 23 is arranged to extend in the axial direction D1. Specifically, each of the magnet insertion holes 23 penetrates the rotor core 21 in the axial direction D1. The plurality of permanent magnets 22 are inserted into each of the magnet insertion holes 23.

[0015] The stator 3 is provided on the outer side in the radial direction D2 of the rotor 2. The stator 3 is disposed so as to face the rotor 2 in the radial direction D2. Therefore, the radial gap motor according to the first embodiment is an inner rotor motor.

[0016] The stator 3 includes a stator core 31 and a plurality of coils 32. The stator core 31 is made up of a plurality of steel plates stacked in the axial direction D1. Each of the plurality of coils 32 is provided in the stator core 31. The plurality of coils 32 are arranged in a row in the circumferential direction D3. A current is supplied to each of the coils 32 from a power supply device (not shown).

[0017] The case 4 is disposed so as to surround the rotor 2 and the stator 3. The stator 3 is fixed to the case 4.

[0018] The case 4 includes a tubular portion 41 and a pair of lids 42. The tubular portion 41 is cylindrical in shape. The tubular portion 41 is arranged coaxially with the axis of the rotating shaft 1. The stator 3 is provided on the inner peripheral surface of the tubular portion 41. The tubular portion 41 is arranged between the pair of lids 42 in the axial direction D1. Each of the pair of lids 42 is fixed to the tubular portion 41.

[0019] One of the pair of lids 42 is referred to as a first lid 42a, and the other lid 42 is referred to as a second lid 42b. The first lid 42a is disposed adjacent to the rotor 2 and the stator 3 on one side in the axial direction D1. The second lid 42b is disposed adjacent to the rotor 2 and the stator 3 on the other side in the axial direction D1.

[0020] Each lid 42 includes a lid main body 43 facing the rotor 2 in the axial direction D1, and an arm portion 44 extending from the lid main body 43 in a direction approaching the rotor 2 in the axial direction D1. The arm portion 44 of each lid 42 is cylindrical in shape. The arm portion 44 of each lid 42 is arranged coaxially with the axis of the rotating shaft 1. The arm portion 44 of each lid 42 is inserted into the corresponding rotating shaft groove 13. The arm portion 44 of each lid 42 is arranged so that at least a portion of the arm portion 44 overlaps the rotor 2 when viewed along the radial direction D2.

[0021] Fig. 2 is a cross-sectional view showing the main parts of the radial gap motor of Fig. 1. Fig. 3 is a perspective view showing the main parts of the radial gap motor of Fig. 1. Fig. 4 is a perspective view of the main parts of the radial gap motor of Fig. 3 as seen from the opposite axial direction. Figs. 2, 3, and 4 show a rotating shaft 1, a rotor 2, and a pair of bearings 5.

[0022] Each of the pair of bearings 5 is provided between the rotating shaft 1 and the case 4. Specifically, one of the pair of bearings 5 is provided between the rotating shaft 1 and the first lid 42a, and the other of the pair of bearings 5 is provided between the rotating shaft 1 and the second lid 42b.

[0023] The pair of bearings 5 are arranged to sandwich the flange portion 12 of the rotating shaft 1 in the axial direction D1. Specifically, the pair of bearings 5 are inserted one by one into a pair of rotating shaft grooves 13. Each bearing 5 is arranged between the arm portion 44 of the corresponding lid 42 and the rotating shaft 1 in the radial direction D2.

[0024] Each bearing 5 is arranged so that, when viewed along the radial direction D2, at least a portion of the bearing 5 overlaps the rotor 2. Therefore, the dimension between the pair of bearings 5 in the axial direction D1 is smaller than the dimension of the rotor 2 in the axial direction D1.

[0025] The rotation detector 6 is provided on the second lid 42b of the case 4. The rotation detector 6 detects the rotation of the rotor 2. The detection result of the rotation detector 6 is input to a control device (not shown).

[0026] The brake device 7 is provided on the second lid 42b of the case 4. The brake device 7 brakes the rotation of the rotor 2. The driving of the brake device 7 is controlled by the control device.

[0027] Next, the operation of the radial gap motor according to embodiment 1 will be described. When a current is supplied to each coil 32, an interaction occurs between the magnetic field generated by the permanent magnets 22 and the current flowing through each coil 32. The interaction between the magnetic field generated by the permanent magnets 22 and the current flowing through each coil 32 causes the rotor 2 to rotate in the circumferential direction D3 relative to the stator 3.

[0028] As described above, the radial gap motor in the first embodiment includes the rotating shaft 1, the rotor 2, the stator 3, the case 4, and the bearing 5. The rotor 2 is fixed to the rotating shaft 1. The stator 3 is provided on the outside of the rotor 2 in the radial direction D2. The stator 3 is fixed to the case 4. The bearing 5 is provided across the rotating shaft 1 and the case 4. The bearing 5 is arranged so that at least a portion of the bearing 5 overlaps with the rotor 2 when viewed along the radial direction D2. With this configuration, the dimension between the pair of bearings 5 in the axial direction D1 can be made smaller than the dimension of the rotor 2 in the axial direction D1. This allows the dimension of the radial gap motor in the axial direction D1 to be reduced.

[0029] Furthermore, in the radial gap motor according to the first embodiment, a rotating shaft groove 13 into which a bearing 5 is inserted is formed on the surface of the rotating shaft 1 facing the axial direction D1. With this simple configuration, the dimension between the pair of bearings 5 in the axial direction D1 can be made smaller than the dimension of the rotor 2 in the axial direction D1. This makes it possible to easily reduce the dimension of the radial gap motor in the axial direction D1.

[0030] Furthermore, in the radial gap motor according to the first embodiment, the rotating shaft groove 13 is disposed in the middle of the rotating shaft 1 in the radial direction D2. With this configuration, the dimension between the pair of bearings 5 in the axial direction D1 can be made smaller than the dimension of the rotor 2 in the axial direction D1 without reducing the contact area between the rotating shaft 1 and the rotor 2.

[0031] Furthermore, in the radial gap motor according to the first embodiment, the case 4 has a lid 42 disposed adjacent to the rotor 2 in the axial direction D1. The lid 42 includes a lid main body 43 facing the rotor 2 in the axial direction D1, and an arm portion 44 extending from the lid main body 43 in a direction approaching the rotor 2 in the axial direction D1. The arm portion 44 is disposed so that at least a portion of the arm portion 44 overlaps with the rotor 2 when viewed along the radial direction D2. The bearing 5 is disposed between the arm portion 44 and the rotating shaft 1 in the radial direction D2. With this configuration, the bearing 5 can be easily provided across the rotating shaft 1 and the case 4.

[0032] Embodiment 2 Fig. 5 is a cross-sectional view showing a main part of a radial gap motor according to embodiment 2. In Fig. 3, a rotating shaft 1, a rotor 2, and a pair of bearings 5 are shown.

[0033] A rotor groove 24 is formed on each of the two surfaces of the rotor 2 facing the axial direction D1 that are in the inner portion in the radial direction D2. Each rotor groove 24 is arranged so as to be recessed inward in the axial direction D1 on the surface of the rotor 2 facing the axial direction D1. Each rotor groove 24 is arranged on the inner portion of the rotor 2 in the radial direction D2. Each rotor groove 24 is arranged in a position that overlaps with the outer portion of the rotor 2 in the radial direction D2 when viewed along the radial direction D2. The arm portions 44 of each lid 42 are inserted into the corresponding rotor groove 24.

[0034] Each rotating shaft groove 13 is arranged on the outer side of the flange portion 12 in the radial direction D2. Therefore, the contact area between the rotating shaft 1 and the rotor 2 is smaller than the contact area between the rotating shaft 1 and the rotor 2 in the radial gap motor according to the first embodiment.

[0035] The pair of rotary shaft grooves 13, the pair of rotor grooves 24, and the pair of bearings 5 correspond to one another. The corresponding bearings 5 are inserted across the corresponding rotary shaft grooves 13 and rotor grooves 24.

[0036] Other configurations of the radial gap motor according to the second embodiment are the same as those of the radial gap motor according to the first embodiment.

[0037] As described above, in the radial gap motor according to the second embodiment, rotor grooves 24 into which bearings 5 are inserted are formed on the surface of the rotor 2 facing the axial direction D1. With this simple configuration, the dimension between the pair of bearings 5 in the axial direction D1 can be made smaller than the dimension of the rotor 2 in the axial direction D1. This makes it possible to easily reduce the dimension of the radial gap motor in the axial direction D1.

[0038] Furthermore, in the radial gap motor according to the second embodiment, the rotor grooves 24 are arranged on the inner side in the radial direction D2 of the rotor 2. With this configuration, the dimension between the pair of bearings 5 in the axial direction D1 can be made smaller than the dimension of the rotor 2 in the axial direction D1, without reducing the dimension of the permanent magnet 22 in the axial direction D1.

[0039] In the radial gap motors according to the first and second embodiments, the rotating shaft 1 has been configured such that one rotating shaft groove 13 is formed on each of the two surfaces of the flange portion 12 facing the axial direction D1. However, this configuration is not limiting. The rotating shaft 1 may have a configuration in which the rotating shaft groove 13 is formed on only one of the two surfaces of the flange portion 12 facing the axial direction D1. Even in this case, the dimensions of the radial gap motor in the axial direction D1 can be reduced by inserting a bearing 5 into the rotating shaft groove 13.

[0040] Furthermore, in the radial gap motor according to the second embodiment, the rotor 2 has been described as having a configuration in which one rotor groove 24 is formed on each of the two surfaces of the rotor 2 facing the axial direction D1. However, this configuration is not limited to this. The rotor 2 may have a configuration in which the rotor groove 24 is formed on only one of the two surfaces of the rotor 2 facing the axial direction D1. Even in this case, the dimensions of the radial gap motor in the axial direction D1 can be reduced by inserting a bearing 5 into the rotor groove 24.

[0041] Furthermore, in the radial gap motor according to the second embodiment, the configuration of the rotating shaft 1 has been described in which the rotating shaft groove 13 is formed in the flange portion 12. However, this configuration is not limited to this. The rotating shaft 1 may also be configured such that the rotating shaft groove 13 is not formed in the flange portion 12. In this case, the bearing 5 and the arm portion 44 are inserted only into the rotor groove 24.

[0042] Although the radial gap motors according to the preferred embodiments have been described above, the present invention is not limited to the radial gap motors according to the above-described embodiments. Various modifications and alterations can be made to the radial gap motors according to the above-described embodiments without departing from the scope of the claims. [Explanation of symbols]

[0043] 1 rotating shaft, 2 rotor, 3 stator, 4 case, 5 bearing, 6 rotation detection device, 7 brake device, 11 cylindrical portion, 12 flange portion, 13 rotating shaft groove, 21 rotor core, 22 permanent magnet, 23 magnet insertion hole, 24 rotor groove, 31 stator core, 32 coil, 41 cylindrical portion, 42 lid, 42a first lid, 42b second lid, 43 lid body, 44 arm portion.

Claims

1. A rotation axis (1), a rotor (2) fixed to the rotating shaft (1); a stator (3) provided radially outward of the rotor (2); a case (4) to which the stator (3) is fixed; a bearing (5) provided across the rotating shaft (1) and the case (4); Equipped with The bearing (5) is arranged so that at least a portion of the bearing (5) overlaps the rotor (2) when viewed in the radial direction.

2. 2. The radial gap motor according to claim 1, wherein a groove (13) into which the bearing (5) is inserted is formed on an axial surface of the rotating shaft (1).

3. 3. The radial gap motor according to claim 2, wherein the rotary shaft groove (13) is arranged in a radially intermediate portion of the rotary shaft (1).

4. 3. The radial gap motor according to claim 1, wherein a rotor groove (24) into which the bearing (5) is inserted is formed on an axial surface of the rotor (2).

5. 5. The radial gap motor according to claim 4, wherein the rotor grooves (24) are arranged on the inner side in the radial direction of the rotor (2).

6. The case (4) has a cover (42) arranged adjacent to the rotor (2) in the axial direction, The lid (42) a lid body (43) facing the rotor (2) in the axial direction; an arm portion (44) extending from the lid body (43) in the axial direction toward the rotor (2); Including, The arm portion (44) is arranged so that at least a part of the arm portion (44) overlaps with the rotor (2) when viewed along the radial direction, 4. The radial gap type motor according to claim 1, wherein the bearing (5) is disposed between the arm portion (44) and the rotating shaft (1) in the radial direction.

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