Rotating electrical machine

Abstract

A rotating electric machine (1) comprises a motor (2), a substrate (50), a terminal block (5), and a heat sink (40). The terminal block (5) comprises a terminal (80) and fixes the substrate (50). The heat sink (40) houses the motor (2), the substrate (50), and the terminal block (5). The heat sink (40) has an opening (41), and a portion (60) of the terminal block (5) is inserted into the opening (41). The opening (41) has an inner surface (42) that faces the portion (60) of the terminal block (5). The terminal block (5) has a cylindrical portion (60) which has an outer surface (62) facing the inner surface (42). An elastic member (6) is disposed between the inner surface (42) and the outer surface (62).

Description

rotating electrical machines

[0001] The present invention relates to a rotating electric machine.

[0002] In cooling fans used in electronic devices, etc., a technique is known in which a partition plate and a sealing member are provided to ensure waterproofing of the electronic device, etc. In such a configuration, terminals are formed on the motor board in a state where they are exposed through an opening.

[0003] JP 2014-223000 A

[0004] However, in such a configuration, it is difficult to align the motor board with the electronic device connected by the terminals, which may reduce the ease of assembly of the electronic device.

[0005] In one aspect, an object is to provide a rotating electric machine that can improve the ease of assembling terminals.

[0006] In one aspect, a rotating electric machine includes a motor, a substrate, a terminal block, and a heat sink. The terminal block has terminals and fixes the substrate. The heat sink houses the motor, substrate, and terminal block. The heat sink has an opening into which a portion of the terminal block is inserted. The opening has an inner surface facing the portion of the terminal block. The terminal block has a tubular portion with an outer surface facing the inner surface. An elastic member is disposed between the inner surface and the outer surface.

[0007] According to one aspect, the ease of assembling the terminal can be improved.

[0008] Fig. 1 is a top view showing an example of a fan motor according to an embodiment. Fig. 2 is an exploded perspective view showing an example of a fan motor according to an embodiment. Fig. 3 is a side cross-sectional view showing an example of a fan motor according to an embodiment. Fig. 4 is another side cross-sectional view showing an example of a fan motor according to an embodiment. Fig. 5 is an enlarged cross-sectional view showing an example of a fan motor according to an embodiment. Fig. 6 is a perspective view showing an example of a plate portion according to a modified example.

[0009] Hereinafter, an embodiment of a rotating electric machine disclosed herein will be described in detail with reference to the drawings. Note that the dimensional relationships and ratios of elements in the drawings may differ from reality. The drawings may also include portions where the dimensional relationships and ratios differ. To facilitate understanding of the description, the drawings may illustrate a coordinate system in which the direction in which a shaft 31 (described later) extends is the Z-axis direction, the side on which an impeller 9 is disposed is the positive side of the Z-axis, and the side on which a heat sink 40 is disposed is the negative side of the Z-axis.

[0010] [Embodiment] First, a fan motor according to an embodiment will be described with reference to Figures 1 and 2. Figure 1 is a top view showing an example of a fan motor according to an embodiment. Figure 2 is an exploded perspective view showing an example of a fan motor according to an embodiment. The fan motor 1 is an example of a rotating electric machine.

[0011] 2, the fan motor 1 includes a motor 2, a circuit board 50, a terminal block 5, an impeller 9, and a heat sink 40. Note that the heat sink 40 and the terminal block 5 are shown transparently in Fig. 1. This allows the fins 45 formed on the positive side of the heat sink 40 in the Z-axis direction, as well as the circuit board 50 and impeller 9 arranged on the positive side of the heat sink 40 in the Z-axis direction, to be visible, as shown by the dashed lines.

[0012] The heat sink 40 houses the motor 2, the circuit board 50, and the terminal block 5. The heat sink 40 has an opening 41 and a plurality of fins 45. An electronic device (not shown) is also disposed in the heat sink 40. The electronic device is disposed, for example, in a position facing the fins 45 in the Z-axis direction as an object to be cooled. The heat sink 40 is formed of a metal such as aluminum die-cast. The heat sink 40 may have thread grooves 47 to 49 into which the screws 97 to 99 shown in FIG. 2 are threadedly engaged.

[0013] The opening 41 is a through-hole that passes through the heat sink 40 in the Z-axis direction and has, for example, a substantially circular cross section. As shown in FIG.

[0014] The terminal block 5 secures the substrate 50. As shown in Fig. 2, the terminal block 5 includes a cylindrical portion 60, a plate portion 70, and three terminals 80. The terminal block 5 is coupled to the heat sink 40 by, for example, screws 97 to 99 shown in Fig. 2.

[0015] The terminals 80 connect the substrate 50 to an external power supply and control circuit (not shown). As shown in FIGS. 2 to 4 , the three terminals 80 are fixed to the cylindrical portion 60 of the terminal block 5 so as to penetrate the terminal block 5 in the Z-axis direction and line up in the Y-axis direction. FIG. 3 is a side cross-sectional view showing an example of a fan motor according to an embodiment. FIG. 4 is another side cross-sectional view showing an example of a fan motor according to an embodiment. FIG. 3 shows a cross-section taken along line A-A in FIG. 1 . FIG. 4 shows a cross-section taken along line B-B in FIG. 1 . Hereinafter, when the three terminals 80 are to be distinguished from one another, they may be referred to as terminals 84, 85, and 86, respectively, starting from the positive side on the Y-axis, as shown in FIG. 3 . The terminals 84 to 86 are fixed to the terminal block 5 by, for example, insert molding, so as to extend from the inside of the heat sink 40 through the opening 41 to the outside (from the positive side to the negative side on the Z-axis).

[0016] The cylindrical portion 60 is a generally circular portion that protrudes toward the negative side in the Z-axis direction of the terminal block 5. As shown in Fig. 3 , the cylindrical portion 60 has an outer surface 62 and a step portion 63. The cylindrical portion 60 is inserted into the opening 41 of the heat sink 40. In this case, the outer surface 62 faces the inner surface 42 of the opening 41 of the heat sink 40, as shown in Fig. 3 . The cylindrical portion 60 is an example of a part of the terminal block.

[0017] 2 and 3 , in this embodiment, an O-ring 6 is disposed between the inner surface 42 of the opening 41 of the heat sink 40 and the outer surface 62 of the tubular portion 60 of the terminal block 5. The O-ring 6 is an annular member having a sealing function, formed of an elastic material such as rubber. The terminal block 5 is inserted into the opening 41 with the O-ring 6 disposed on the step portion 63 of the tubular portion 60, for example. As a result, the O-ring 6 acts as a packing between the outer surface 62 of the tubular portion 60 and the inner surface 42 of the opening 41, thereby sealing the opening 41 and the tubular portion 60. The O-ring 6 is an example of an elastic member.

[0018] 3, the opening 41 may have a flange 44 that protrudes radially inward on the negative side of the Z axis. This configuration can prevent, for example, the O-ring 6 from coming off on the negative side of the Z axis or other components from coming into contact with the O-ring 6. In addition to the above effects, by ensuring a certain degree of clearance between the outer surface 62 of the tubular portion 60 and the flange 44 of the opening 41, it is possible to easily visually check if the O-ring 6 has been left installed.

[0019] As shown in Figures 2 and 4, the plate portion 70 of the terminal block 5 is located on the positive side of the Z axis relative to the cylindrical portion 60, and extends in a direction intersecting the cylindrical portion 60, for example, in the X-axis direction and the Y-axis direction. As shown in Figures 2 and 3, the plate portion 70 is formed with a flange 71, a through hole 72, and terminal support portions 74 to 76. The terminal support portions 74 to 76 are, for example, filler material, which will be described later. Furthermore, as shown in Figure 2, the plate portion 70 may be formed with screw holes 77 to 79 that are threadedly engaged with screws 97 to 99, respectively.

[0020] As shown in Fig. 3, the flange 71 protrudes toward the positive side in the Z axis direction and is formed in a generally annular shape so as to surround the circuit board 50 from the outside in the radial direction. As shown in Fig. 2, the shaft 31 of the motor 2 is inserted into the through-hole 72 from the positive side in the Z axis direction. As shown in Fig. 3, the terminal support portions 74 to 76 support terminals 84 to 86, respectively, from the positive side in the Z axis direction. Note that the flange 71 is not visible in Fig. 2.

[0021] The impeller 9 rotates in conjunction with the motor 2, drawing in air from the positive side of the Z axis and discharging the air in a direction intersecting the Z axis, as shown by the arrows in Fig. 3. This cools the fins 45 that are located on the negative side of the impeller 9 in the Y axis, as shown in Fig. 1. The impeller 9 is made of, for example, resin.

[0022] The motor 2 includes the stator 10, rotor 20, shaft 31, and bearing holder 32 shown in Fig. 2, as well as bearings 34 and 35 shown in Fig. 4. As shown in Fig. 4, the motor 2 in this embodiment is a so-called outer rotor type motor in which the rotor 20 is disposed radially outward from the stator 10. The bearings 34 and 35 are housed in the bearing holder 32 and are not visible in Fig. 2.

[0023] As shown in FIG. 5 , the stator 10 includes a stator core 11, a coil 12, and an insulator 13. FIG. 5 is an enlarged cross-sectional view showing an example of a fan motor according to an embodiment. FIG. 5 is an enlarged view of a portion indicated by a frame F1 in FIG. 4 . The stator core 11 is an annular member formed by laminating multiple layers of magnetic material, such as stainless steel or magnetic steel plates, in the Z-axis direction. The insulator 13 is formed of an insulating material, such as resin. The insulator 13 covers the stator core 11, for example, from both the positive and negative sides in the Z-axis direction. The coil 12 is wound around the stator core 11 via the insulator 13. The coil 12 is connected to, for example, wiring 53 of a substrate 50 shown in FIG. 2 .

[0024] As shown in Fig. 5, the rotor 20 includes a magnet 21 and a holder 22. The magnet 21 is a substantially cylindrical permanent magnet such as a neodymium magnet, and is disposed radially outward of the stator 10. The holder 22 holds the magnet 21. The holder 22 also connects the shaft 31 and the impeller 9. The shaft 31 is rotatably supported by the bearing holder 32 via bearings 34 and 35. In this configuration, the shaft 31 serves as the rotation axis of the motor 2 and the impeller 9. The shaft 31 and the impeller 9 rotate in conjunction with the rotation of the rotor 20.

[0025] The bearing holder 32 is fixed to the terminal block 5. In this embodiment, as shown in Fig. 5 , an engaging portion 33 formed on the bearing holder 32 engages with an engaged portion 73 formed on the plate portion 70 of the terminal block 5. The engaged portion 73 is formed, for example, in a substantially annular shape so as to surround the through hole 72, and as shown in Fig. 5 , protrudes in the positive direction along the Z axis. With this configuration, there is no need to interpose a member between the stator 10 and the rotor 20 to hold the stator 10 to the heat sink 40. This makes it possible to suppress a deterioration in motor characteristics due to an increase in the gap G1 between the stator 10 and the rotor 20 shown in Fig. 5 .

[0026] The board 50 supplies power to the motor 2 via terminals 80 and wiring 53 shown in Fig. 2. The board 50 in this embodiment is an annular printed circuit board made of, for example, resin and having a substantially circular opening 52 as shown in Fig. 2. The board 50 is disposed in a position where the shaft 31 of the motor 2 is inserted into the opening 52, for example.

[0027] In the embodiment, the substrate 50 is assembled to the terminal block 5 after the terminal block 5 has been previously assembled to the heat sink 40. With this configuration, the substrate 50 can be assembled while ensuring the waterproofness of the electronic device, etc., thereby improving the ease of assembly of the substrate 50.

[0028] The terminals 84 to 86 are electrically connected to the substrate 50 by, for example, being soldered while being inserted into the terminal holes 54 to 56 of the substrate 50 shown in Fig. 2. More specifically, as shown in Fig. 3, a portion of the end portion of the terminals 84 to 86 fixed to the terminal block 5 on the negative side in the Z axis (exposed surface 83 of second portion 82 described later) is exposed from the opening 41 and connected to a power supply or the like (not shown). Furthermore, the end portion of the terminals 84 to 86 shown in Fig. 3 on the positive side in the Z axis (first portion 81 described later) is inserted into the terminal holes 54 to 56 of the substrate 50 shown in Fig. 2.

[0029] In the embodiment, the terminals 84 to 86 are fixed to the terminal block 5 by insert molding and then inserted into the terminal holes 54 to 56 of the circuit board 50, respectively. With this configuration, the terminals 84 to 86 can be easily inserted into the terminal holes 54 to 56 of the circuit board 50, thereby improving the ease of assembling the terminals.

[0030] 4, the radial width W1 of the opening 41 of the heat sink 40 is smaller than the radial width W2 of the substrate 50. In this configuration, the substrate 50 is not accommodated in the opening 41 in the Z-axis direction.

[0031] The components are arranged in the following order from the negative side in the Z-axis direction: opening 41, terminal block 5, and circuit board 50. In this state, as shown in FIG. 2 , the plate portion 70 is positioned between the opening 41 and circuit board 50 when viewed from the Z-axis direction. Furthermore, in this embodiment, the radial width W3 of the plate portion 70 of the terminal block 5 shown in FIG. 4 is larger than the radial width W2 of the circuit board 50 shown in FIG. 4 and is also larger than the radial width D1 of the impeller 9 shown in FIG. 2 . With this configuration, the plate portion 70 blocks the gaps between the opening 41 of the heat sink 40 and the circuit board 50 and the impeller 9, thereby further improving waterproofing. Furthermore, by making the radial width W2 of the circuit board 50 smaller than the radial width D1 of the impeller 9, the waterproofing of the circuit board 50 can also be improved.

[0032] Furthermore, in a top view, the opening 41 is formed at a position that does not overlap with the rotational axis of the motor 2. Specifically, as shown in FIG. 2 , a portion X1 of the heat sink 40 that faces the shaft 31 in the Z-axis direction is located outside the opening 41. That is, in this embodiment, the center of the opening 41 does not coincide with the center of the shaft 31. Furthermore, the bearing holder 32 is covered by the heat sink 40 in the Z-axis direction. By offsetting the opening 41 from the rotational axis of the impeller 9 in this manner, the distance between the opening 41 and the opening 52 and the through hole 72 through which the shaft 31, which serves as the rotational axis of the impeller 9, is extended, as shown in FIG. 5 , and a labyrinth structure is formed. This prevents water from seeping in toward the negative side in the Z-axis direction via the bearing holder 32 inserted through the through hole 72, thereby further improving waterproofing.

[0033] 1, the opening 41 of the heat sink 40 and the substrate 50 partially overlap in top view. In this case, the terminal holes 54 to 56 of the substrate 50 shown in FIG. 2 are formed at positions that overlap with the opening 41 in top view. With this configuration, the terminal 80 can be connected to the substrate 50 by inserting the terminal 80 into the negative Z-axis direction, thereby improving the ease of assembly of the terminal 80 and the substrate 50 in the fan motor 1.

[0034] As described above, the fan motor 1 in this embodiment includes the motor 2, the circuit board 50, the terminal block 5, and the heat sink 40. The terminal block 5 has terminals 80 and secures the circuit board 50. The heat sink 40 houses the motor 2, the circuit board 50, and the terminal block 5. The heat sink 40 has an opening 41 into which a portion 60 of the terminal block 5 is inserted. The opening 41 has an inner surface 42 that faces the portion 60 of the terminal block 5. The terminal block 5 has a tubular portion 60 that faces the inner surface 42. The elastic member 6 is disposed between the inner surface 42 and the outer surface 62. This configuration facilitates alignment of the terminals 80 and the circuit board 50, improving the ease of assembling the terminals.

[0035] Terminal 80 will be described with reference to Fig. 5. Although only terminal 85 is shown in the cross section shown in Fig. 5, terminals 84 and 86 also have the same cross-sectional shape as in Fig. 5, and therefore the following description of terminal 85 shown in Fig. 5 also applies to the entire terminal 80 including terminals 84 and 86.

[0036] As shown in Fig. 5 , the terminal 85 includes a first portion 81 that extends in the rotation axis direction (Z-axis direction) and is connected to the substrate 50, and a second portion 82 that extends in the radial direction and is exposed from the terminal block 5. The first portion 81 is inserted into the terminal hole 55 of the substrate 50 and soldered thereto, thereby being electrically connected to the substrate 50. As shown in Fig. 5 , the second portion 82 extends in the radial direction (X-axis direction) along the terminal block 5, and has an exposed surface 83 that is partially exposed from the terminal block 5 on the negative side in the Z-axis direction. An external power supply or control circuit (not shown) can be electrically connected to this exposed surface 83.

[0037] The exposed surface 83 is housed inside the tubular portion 60. In other words, the exposed surface 83 is located closer to the impeller 9, i.e., on the positive side in the Z-axis direction, than the end of the tubular portion 60 on the negative side in the rotational axis direction (Z-axis direction). Furthermore, the second portion 82 having the exposed surface 83 is disposed inside the circle formed by the flange 71 in the radial direction.

[0038] The first portion 81 of the terminal 85 is disposed so as to partially overlap the motor 2 in the radial direction. For example, the motor 2 and the first portion 81 overlap in a top view. This allows the fan motor 1 to have a smaller dimension in the Z-axis direction compared to a configuration in which the first portion 81 extending in the Z-axis direction does not overlap the motor 2 in the radial direction. This contributes to a more compact device. Furthermore, since only a portion of the exposed surface 83 of the terminal 85 is exposed, the dimension in the Z-axis direction can be reduced compared to a configuration in which the entire surface is exposed. This contributes to a more compact device. Furthermore, since the second portion 82 having the exposed surface 83 is disposed radially within the circle formed by the flange 71, the terminal 85 can be brought closer to the motor 2. This allows the fan motor 1 to have a smaller radial dimension.

[0039] As shown in Fig. 5, a filler 75 is provided adjacent to the terminal 85. The filler 75 functions as a terminal support and a sealing material, and can improve the waterproof and dustproof performance of the terminal 85. As shown in Fig. 3, fillers 74 and 76 are similarly provided at positions adjacent to the terminals 84 and 86.

[0040] [Modifications] While the configuration of the embodiment has been described above, the embodiment is not limited to this. For example, the terminals 80 may be fixed to the terminal block 5 in advance before being connected to the board 50, and may be fixed by being press-fitted into the terminal block 5 instead of by insert molding.

[0041] Furthermore, as shown in FIG. 6 , the plate portion 90 in this modified example has one surface 90a and another surface 90b facing the rotation axis direction (Z-axis direction), and ribs 91 may be provided on both or one of the surfaces 90a and 90b. FIG. 6 is a perspective view showing an example of the plate portion in this modified example. The ribs 91 may extend radially from the center of the plate portion 90, or may extend radially or circumferentially as shown in FIG. 6 . The ribs 91 can increase the surface rigidity of the plate portion 90, thereby preventing warping of the plate portion 90. Furthermore, the cylindrical portion 60, which is located on the negative side of the Z-axis relative to the plate portions 70 and 90, also prevents warping of the plate portions 70 and 90.

[0042] Furthermore, the elastic member placed between the inner surface 42 of the opening 41 of the heat sink 40 and the outer surface 62 of the tubular portion 60 of the terminal block 5 is not limited to the O-ring 6, but may be other members such as an elastic adhesive.

[0043] As long as the opening 41 and the cylindrical portion 60 can be sealed by the elastic member, the cross-sectional shapes of the opening 41 and the cylindrical portion 60 are not limited to the generally circular shape as shown in Fig. 2, etc., and may be other shapes such as an oval shape or a rectangular shape. In particular, when an adhesive or the like is used as the elastic member, the degree of freedom in the shape of the opening 41 and the cylindrical portion 60 can be improved.

[0044] Furthermore, in the embodiment, the bearing holder 32 engages with the through-hole 72 provided in the plate portion 70 of the terminal block 5, but the embodiment is not limited to this. For example, the plate portion 70 may be configured so that no through-hole is formed in the portion where the bearing holder 32 engages. For example, when a sleeve is used as the bearing, or when the bearing is inserted by press-fitting from the positive side on the Z axis, the portion where the bearing holder 32 engages may be modified to be a recess rather than a through-hole. With such a configuration, the waterproofness of the terminal block 5 can be further improved.

[0045] Furthermore, the motor in the embodiment is not limited to a so-called outer rotor type motor, but may be an inner rotor type or other type of motor.

[0046] 3 is an example of the relationship between the height of the tip end portion of the tubular portion 60 in the Z-axis direction and the height of the flange 44 of the opening 41. For example, by extending the outer surface 62 of the tubular portion 60 in the negative direction of the Z-axis, the outer surface 62 can be used as a guide for pouring an adhesive or the like. This improves the ease of assembly when an adhesive or the like is interposed between the tubular portion 60 and the opening 41.

[0047] While the present invention has been described above based on the embodiments and modifications, it goes without saying that the present invention is not limited to the embodiments and modifications, and various modifications are possible without departing from the spirit of the present invention. Such modifications without departing from the spirit of the present invention are also included in the technical scope of the present invention, and this will be clear to those skilled in the art from the description of the claims.

[0048] 1 Fan motor, 2 Motor, 5 Terminal block, 6 O-ring, 9 Impeller, 10 Stator, 11 Stator core, 12 Coil, 13 Insulator, 20 Rotor, 21 Magnet, 22 Holder, 31 Shaft, 32 Bearing holder, 33 Engagement portion, 34, 35 Bearing, 40 Heat sink, 41 Opening, 42 Inner surface, 44 Flange, 45 Fin, 47 to 49 Thread groove, 50 Board, 52 Opening, 53 Wiring, 54 to 56 Terminal hole, 60 Cylinder portion, 62 Outer surface, 63 Step portion, 70, 90 Plate portion, 71 Flange, 72 Through hole, 73 Engaged portion, 74 to 76 Terminal support portion (filler), 77 to 79 Screw hole, 80, 84 to 86 Terminal, 91 Rib, 97 to 99 Screw

Claims

1. A rotating electric machine comprising: a motor; a circuit board; a terminal block having terminals and for fixing the circuit board; and a heat sink for housing the motor, the circuit board, and the terminal block, wherein the heat sink has an opening into which a part of the terminal block is inserted, the opening having an inner surface facing the part of the terminal block, the terminal block having a tubular portion having an outer surface facing the inner surface, and an elastic member being disposed between the inner surface and the outer surface.

2. A rotating electric machine as set forth in claim 1, wherein a terminal is fixed to said terminal block, the terminal extending from inside said heat sink through said opening toward the outside, and said terminal is electrically connected to said substrate.

3. A rotating electric motor as described in claim 1, wherein the terminal block has a plate portion extending in a direction intersecting the cylindrical portion, and when viewed from the direction of the rotation axis, the plate portion is positioned at a position sandwiched between the opening and the substrate.

4. A rotating electric machine according to claim 1, wherein the width of said opening in the radial direction is smaller than the width of said substrate in the radial direction.

5. A rotating electric machine according to claim 1, wherein the opening is formed at a position that does not overlap with a rotating shaft of the motor when viewed from above.

6. A rotating electric machine as claimed in claim 1 or 2, wherein the terminal comprises a first portion extending in the direction of the rotation axis and a second portion extending in the radial direction, the first portion is connected to the board, and a part of the second portion has an exposed surface exposed from the terminal block.