Driving device

Abstract

To provide a driving device capable of avoiding connection loosening between a motor unit and a circuit unit due to external force.SOLUTION: A driving device 10 comprises a motor unit 20, a circuit unit 40, and a housing 60. The motor unit 20 has: a stator 22 in which a motor winding 21 is wound; a rotor 23 that rotates by energizing the motor winding; and a shaft 25 that rotates integrally with the rotor 23. The circuit unit 40 has a circuit board 41 on which an electronic component 42 related to energizing control of the motor winding 21 is mounted. The housing 60 has a motor housing part 61 for accommodating the motor unit 20 and a circuit housing part 71 for accommodating the circuit unit 40, and is formed with a heat dissipation fin 65 on an outer side surface. The motor housing part 61, the circuit housing part 71 and the heat dissipation fin 65 are integrally molded.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a drive device. [Background technology]

[0002] Conventionally, there has been known a mechanically and electrically integrated drive unit in which a motor body and a drive circuit are housed in a case. For example, in Patent Document 1, a heat dissipation fin is provided on a motor case body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2015-146710 A Summary of the Invention [Problem to be solved by the invention]

[0004] In Patent Document 1, the motor case body and the electrical equipment case are screwed together. Here, when an external force such as wind pressure is applied to the heat dissipation fins, the device vibrates, which may weaken the connection between the motor body and the drive circuit.

[0005] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide a drive device that can prevent loosening of the connection between a motor unit and a circuit unit due to an external force. [Means for solving the problem]

[0006] The drive device of the present invention includes a motor section (20), a circuit section (40), and a housing (60). The motor section includes a stator (22) around which a motor winding (21) is wound, a rotor (23) that rotates when current is applied to the motor winding, and a shaft (25) that rotates integrally with the rotor. The circuit section includes a circuit board (41) on which electronic components (42) related to current control of the motor winding are mounted.

[0007] The housing portion has a motor housing portion (61) that houses the motor portion, and a circuit housing portion (71) that houses the circuit portion, and has heat dissipation fins (65) formed on the outer surface. The motor housing portion, the circuit housing portion, and the heat dissipation fins are molded as a single unit. This makes it possible to prevent the connection between the motor housing portion and the circuit housing portion from loosening even if an external force such as wind pressure is applied to the heat dissipation fins. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic diagram showing an electric motorcycle according to a first embodiment. [Diagram 2] FIG. 1 is a perspective view of a drive device according to a first embodiment. [Diagram 3] FIG. 2 is a plan view of the drive device according to the first embodiment. [Figure 4] 4 is a view taken in the direction of the arrow IV in FIG. 3. [Diagram 5] FIG. 4 is a view taken in the direction of the arrow V in FIG. [Figure 6] 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 11 is a plan view of a drive device according to a second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] (First embodiment) DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A driving device according to the present invention will be described below with reference to the drawings. In the following, in a number of embodiments, substantially the same components are designated by the same reference numerals, and description thereof will be omitted.

[0010] A drive device according to a first embodiment is shown in Figs. 1 to 6. As shown in Fig. 1, the drive device 10 is applied to, for example, an electric motorcycle 90. The electric motorcycle 90 is provided with a main battery 96 of, for example, 48 [V], an auxiliary battery 97 of, for example, 12 [V], and the drive device 10. The drive device 10 is connected to the main battery 96 as a battery, and is driven by the power of the main battery 96. In Fig. 1, the drive device 10 is provided on the rear wheel 92 side of the electric motorcycle 90, but the drive device 10 may be provided on the front wheel 91 side, or on the front wheel 91 and the rear wheel 92.

[0011] 2 to 6, the drive device 10 includes a motor unit 20, a circuit unit 40, and a housing 60. The drive device 10 is a so-called "mechanically and electrically integrated" type in which the circuit unit 40 is provided on one side of the motor unit 20 in the axial direction.

[0012] The motor unit 20 is, for example, a three-phase brushless motor, and the driving force is transmitted to the rear wheel 92 via gears (not shown) etc. The electric motorcycle 90 runs using the driving force of the motor unit 20, and the motor unit 20 is a running motor (so-called main motor).

[0013] 6, the motor section 20 has a stator 22 around which the motor windings 21 are wound, a rotor 23, and a shaft 25. The stator 22 is fixed to a housing 60. The rotor 23 is provided radially inside the stator 22 and is provided to be rotatable relative to the stator 22.

[0014] The shaft 25 is fitted into the rotor 23 and rotates together with the rotor 23. The shaft 25 is rotatably supported by bearings 251 and 252. One end of the shaft 25 is exposed from the housing 60 toward the circuit unit 40, and a magnet 255 is provided thereon. The other end of the shaft 25 is an output end 258, which is exposed from the housing 60 on the side opposite the circuit unit 40. The output end 258 is connected to the rear wheel 92 via a reduction gear or the like (not shown). As a result, the rear wheel 92 is driven by the driving force of the motor unit 20. Hereinafter, a virtual line extending from the axis of the shaft 25 is referred to as the rotation axis Ax. The axial direction of the motor unit 20 is referred to as the "motor axial direction" or simply the "axial direction" as appropriate.

[0015] The circuit section 40 has a circuit board 41. The circuit board 41 is formed into a shape corresponding to a circuit housing section 71 described later, placed on a board fixing section 74, and fixed to the circuit housing section 71 by fixing members such as screws (not shown). Various electronic components 42 related to the drive control of the motor section 20, such as a switching element for switching the power supply to the motor windings 21 and a rotation angle sensor, are mounted on the circuit board 41. In FIG. 6, one element is shown as an example of the electronic components 42. The rotation angle sensor is mounted at a position where the rotating magnetic field of the magnet 255 can be detected. This makes it possible to detect the rotation of the motor section 20.

[0016] As shown in Figs. 2 to 6, the housing 60 has a motor housing portion 61 that houses the motor portion 20, and a circuit housing portion 71 that houses the circuit portion 40. The circuit housing portion 71 is formed on one axial side of the motor housing portion 61, extending to the radially outer side of the motor housing portion 61. In the circuit housing portion 71, a portion connected to the motor housing portion 61 is referred to as a connection portion 711, and a portion extending from the motor housing portion 61 is referred to as an extension portion 712. The motor housing portion 61 and the circuit housing portion 71 are integrally molded from a metal material such as aluminum. The housing 60 is integrally molded, for example, by sand casting and cutting, or by aluminum die casting.

[0017] A frame member 81 is attached to the side of the housing 60 opposite the circuit section 40 with fixing members 69 such as screws. A bearing holder 811 is provided on the frame member 81, and holds a bearing 251. A cover 85 made of, for example, metal or resin is attached to the circuit section 40 side of the housing 60 with fixing members such as screws (not shown). This makes it possible to prevent foreign matter such as water droplets and dust from entering the inside of the housing 60.

[0018] Hereinafter, the area where the tube portion 63 of the motor housing portion 61 is projected in the axial direction will be referred to as the "motor area," and the area where the extension portion 712 is projected in the axial direction will be referred to as the "extension area." Additionally, the upper side of the paper in Fig. 6 will be referred to as the "cover side," the lower side will be referred to as the "output end side," the direction in which the extension portion 712 extends (i.e., the vertical direction on the paper in Fig. 3) will be referred to as the extension direction, and the direction perpendicular to the extension direction (i.e., the horizontal direction on the paper in Fig. 3) will be referred to as the width direction.

[0019] The motor housing 61 has a bottom 62, a cylindrical portion 63, heat dissipation fins 65, a frame mounting portion 67, etc., and is formed in a generally cylindrical shape with a bottom that opens to the output end side. The bottom 62 is provided on the circuit portion 40 side, and a bearing holder 621 is formed in the center. The bearing 252 is provided in the bearing holder 621.

[0020] The stator 22 is fixed to the radially inner side of the cylindrical portion 63. A heat dissipation fin 65 is formed on the radially outer side of the cylindrical portion 63. The heat dissipation fin 65 is formed in an annular shape protruding radially outward from the cylindrical portion 63. The heat dissipation fin 65 is formed in multiple stages in the axial direction. The number and shape of the heat dissipation fins 65 can be set arbitrarily depending on the axial length of the motor portion 20, etc.

[0021] On the output end side of the cylindrical portion 63, a plurality of frame mounting portions 67 are provided which protrude radially outward from the cylindrical portion 63. In this embodiment, five frame mounting portions 67 are formed at approximately equal intervals. The multiple stages of heat dissipation fins 65 on the output end side are provided with cutout portions 651. The frame mounting portions 67 are disposed in the cutout portions 651. That is, the frame mounting portions 67 are disposed adjacent to the heat dissipation fins 65 in the circumferential direction. By arranging the heat dissipation fins 65 and the frame mounting portions 67 so as to overlap in the axial direction, the axial size can be reduced.

[0022] 3, one of the five frame mounting parts 67 is provided on the connection part 711 side, on an imaginary line Ld that passes through the rotation axis Ax and divides the housing 60 into two parts along the longitudinal direction. The remaining four frame mounting parts 67 are provided symmetrically on either side of the imaginary line Ld, and two of them are provided at the boundary between the motor area and the extension area.

[0023] The circuit housing portion 71 has an extended floor portion 72, an erected wall 73, etc., and is formed into a shape that combines a semicircle and a rectangle as a whole when viewed from the cover side. The semicircle portion is provided within the motor area. The rectangular portion is formed by extending from the semicircle portion to the outside of the motor area. By forming the circuit board 41 to extend to the outside of the motor area, the mounting area of ​​the circuit board 41 can be made larger than when the circuit housing portion 71 is formed within the motor area.

[0024] The extension floor portion 72 is formed to extend radially outward from the motor housing portion 61 substantially perpendicular to the rotation axis Ax. The extension floor portion 72 is provided closer to the output shaft than the cover-side end face of the bottom portion 62, and is connected to the cylindrical portion 63 at a location that does not interfere with the heat dissipation fins 65. The erected wall 73 is erected along the outer edge of the circuit housing portion 71.

[0025] The circuit board 41 and the electronic components 42 mounted on the circuit board 41 are housed in an accommodation space surrounded by the cover side surface of the bottom 62 of the motor housing portion 61, the extended floor portion 72, and the upright wall 73. In the motor area, the output end side of the bottom 62 is the motor housing portion 61, and the cover side is the circuit housing portion 71, and the bottom 62 can also be considered as a partition wall that separates the motor housing portion 61 and the circuit housing portion 71.

[0026] The connector 78 is disposed in the extension region and attached to the tip side of the extension floor portion 72. The opening of the connector 78 faces the output end side (i.e., the lower side of the paper in FIG. 5) and is provided so that a harness (not shown) can be inserted and removed. That is, the insertion and removal direction of the connector 78 in this embodiment is parallel to the rotation axis Ax. The orientation of the opening and the insertion and removal direction may be different. This makes it possible to effectively utilize the dead space created by extending the circuit housing portion 71 in the radial direction.

[0027] The connector 78 has a power supply connector 781 and a signal connector 782. The power supply connector 781 is connected to the main battery 96 via a harness or the like. The signal connector 782 is connected to an external sensor or a communication circuit via a harness or the like, and is used to send and receive various signals. In this embodiment, the main battery 96 corresponds to the "battery".

[0028] The circuit housing 71 is provided with a cover attachment portion 75 for attaching the cover 85. The cover attachment portions 75 are provided at six locations in total, three on each side, approximately parallel to each other across the imaginary line Ld. The cover attachment portions 75 are provided on both sides of the imaginary line Ld, on the outside of the semicircular portion of the connection portion 711, at the end on the extension portion 712 side, and at a location that is the boundary between the connection portion 711 and the extension portion 712. Although the cover attachment portion 75 is located below the cover 85, for the sake of explanation, the locations corresponding to the cover attachment portion 75 are numbered with dashed lines in FIG. 3. For the sake of explanation, the cover attachment portions 75 are numbered as 751, 752, and 753 in FIG. 3 from the semicircular portion side of the connection portion 711.

[0029] The cover mounting portion 751 is provided on the outer side of the standing wall 73, and the cover mounting portions 752 and 753 are provided on the inner side of the standing wall 73. The width direction length W1 of the circuit housing portion 71 including the cover mounting portion 75 is smaller than the width direction length W2 of the motor housing portion 61 (i.e., the diameter of the cylindrical portion 63 of the motor housing portion 61).

[0030] The arrangement of the frame mounting portion 67 and the cover mounting portion 75 will be described. As shown in FIG. 4, the axis Lf of the frame mounting portion 67 and the axis Lc of the cover mounting portion 75 are arranged so as to be shifted so as not to overlap. Also, as shown in FIG. 3, in the boundary region between the motor region and the extension region, the axial projection positions of the frame mounting portion 67 and the cover mounting portion 752 are arranged relatively close to each other. Here, on a virtual plane perpendicular to the rotation axis Ax, the axis Af of the frame mounting portion 67 is arranged so as to be shifted so as not to be on a straight line connecting the rotation axis Ax of the motor portion 20 and the axis Ac of the cover mounting portion 75. In other words, the rotation axis Ax, the axis Af of the frame mounting portion 67, and the axis Ac of the cover mounting portion 75 are not arranged on the same straight line.

[0031] The drive device 10 of this embodiment is connected to a main battery 96, and when a relatively high voltage (for example, 96 V when two 48 V main batteries 96 are connected in series) is applied, the drive device 10 becomes hot due to heat generation in the circuit section 40, etc., and therefore heat countermeasures are required. In this embodiment, heat dissipation fins 65 are provided on the motor housing section 61 as a heat countermeasure.

[0032] In this embodiment, the drive unit 10 is applied to an electric motorcycle, and there is a risk that the unit will vibrate due to external forces such as wind pressure acting on the heat dissipation fins 65 and vehicle vibration. Therefore, in this embodiment, the motor housing portion 61 and the circuit housing portion 71 are integrally formed from metal. This makes it possible to prevent loosening or damage to the connection between the motor portion 20 and the circuit portion 40 due to vibration.

[0033] In addition, the drive device 10 has an unbalanced shape in which the extension 712 of the circuit housing section 71 protrudes radially outward from the outer diameter of the motor housing section 61 to one side. Therefore, when the motor section 20 becomes a vibration source, there is a risk of resonance occurring on the circuit section 40 side. Therefore, in this embodiment, the axes of the frame mounting section 67 and the cover mounting section 75 are shifted from each other, and the frame mounting section 67 and the cover mounting section 75 are arranged so as not to be aligned on the same line with respect to the rotation axis Ax. This makes it possible to prevent resonance, and therefore to prevent damage to the frame mounting section 67 and the cover mounting section 75 that are formed to protrude, the board fixing section 74 inside the circuit housing section 71, and the like.

[0034] As described above, the drive device 10 includes the motor section 20, the circuit section 40, and the housing 60. The motor section 20 includes the stator 22 around which the motor windings 21 are wound, the rotor 23 that rotates when current is applied to the motor windings 21, and the shaft 25 that rotates integrally with the rotor 23. The circuit section 40 includes a circuit board 41 on which electronic components 42 related to current control of the motor windings 21 are mounted.

[0035] The housing 60 has a motor housing portion 61 that houses the motor section 20 and a circuit housing portion 71 that houses the circuit section 40, and has heat dissipation fins 65 formed on its outer surface. In this embodiment, the heat dissipation fins 65 are formed radially outside the cylindrical portion 63 of the motor housing portion 61. The motor housing portion 61, the circuit housing portion 71, and the heat dissipation fins 65 are integrally molded.

[0036] By providing the heat dissipation fins 65, it is possible to appropriately dissipate heat generated in the drive unit 10. Furthermore, by forming the motor housing portion 61, the circuit housing portion 71, and the heat dissipation fins 65 as an integrally molded product, even if a load is applied between the motor housing portion 61 and the circuit housing portion 71 due to wind pressure acting on the heat dissipation fins, the entire housing 60 is stable and the occurrence of vibration and damage can be suppressed. Furthermore, because the housing 60 is integrally molded, the connection does not loosen due to vibration or load, as in the case where the motor housing portion 61 and the circuit housing portion 71 are formed separately and fixed with screws or the like.

[0037] The circuit housing portion 71 is provided on one axial side of the cylindrical motor housing portion 61, and has a connection portion 711 connected to the motor housing portion 61, and an extension portion 712 extending from the connection portion 711 radially outward of the motor housing portion 61. Providing the extension portion 712 makes it possible to use a circuit board 41 with a large mounting area. In addition, since the circuit housing portion 71 is actively exposed to the outside, the heat dissipation efficiency of the circuit portion 40 can be improved.

[0038] If the direction in which the extension portion 712 extends is the extension direction and the direction perpendicular to the extension direction is the width direction, then the width direction length W1 of the circuit housing portion 71 is smaller than the width direction length W2 of the motor housing portion 61. In other words, the connection portion 711 is connected to the axial surface of the motor housing portion 61 and is contained within the motor area. This stabilizes the connection between the motor housing portion 61 and the circuit housing portion 71, thereby making it possible to suppress vibration and damage when a load is applied around the boundary area between the connection portion 711 and the extension portion 712.

[0039] The drive device 10 includes a connector 78 that can be connected to the main battery 96 and is provided on the extension portion 712. The connector 78 is provided within a projection area of ​​the extension portion 712 projected in the motor axial direction. In other words, the connector 78 does not protrude from the outer periphery of the circuit housing portion 71. This makes it possible to utilize the dead space that is generated by providing the extension portion 712.

[0040] The drive device 10 includes a frame member 81 and a cover 85. The frame member 81 is attached to a frame attachment portion 67 provided in the motor housing portion 61, and is provided at the end of the housing 60 on the motor housing portion 61 side. The cover 85 is attached to a cover attachment portion 75 provided in the circuit housing portion 71, and is provided at the end of the housing 60 on the circuit housing portion 71 side.

[0041] The frame mounting part 67 and the cover mounting part 75 are provided with their axes Lf, Lc offset from each other. Furthermore, on an imaginary plane perpendicular to the rotation axis Ax of the motor part 20, the frame mounting part 67 is provided such that its axis Af is offset from a straight line connecting the axis Ac of the cover mounting part 75 and the rotation axis Ax. This makes it possible to suppress resonance.

[0042] Second embodiment A second embodiment is shown in Fig. 7. In this embodiment, the connector 79 is different from the above embodiment, so this point will be mainly described. In this embodiment, the connector 79 is provided in the extension portion 712 so as to protrude in the width direction. The opening of the connector 79 faces outward, and is provided so that a harness or the like can be inserted and removed from the outside in the width direction (the right side of the paper in Fig. 7). That is, the insertion and removal direction of the connector 79 in this embodiment is perpendicular to the rotation axis Ax.

[0043] In this embodiment, the connector 79 is provided so as to protrude outward from a projection area of ​​the extension portion 712 projected in the motor axial direction. This allows the harness to be inserted and removed from the outer edge side of the circuit housing portion 71. In addition, the same effects as those of the above embodiment are achieved.

[0044] (Other embodiments) In the above embodiment, the connector has two openings and is provided on the output end side of the extension region of the circuit housing part or on the side of the circuit housing part. In other embodiments, the connector may be provided at any location, such as protruding from the tip end of the circuit housing part in the extension direction. The number of openings is not limited to two, and may be one or three or more. The connector may be divided into multiple parts, for example, with some openings facing sideways and other openings facing axially.

[0045] In the above embodiment, the heat dissipation fins are provided in an annular shape on the radially outer side of the cylindrical portion of the motor housing. In other embodiments, the shape of the heat dissipation fins may be any shape that can promote heat dissipation from the drive device, and may be formed in a shape other than annular. In other embodiments, the heat dissipation fins may be provided at a location other than the cylindrical portion of the motor housing.

[0046] In the above embodiment, the circuit section and the circuit housing section are provided to extend radially outward of the motor housing section. In other embodiments, the shapes of the circuit section and the circuit housing section may be different from those of the above embodiment, for example, the circuit section and the circuit housing section may be formed into a shape that fits within the motor area. Also, in the above embodiment, the width direction length of the circuit housing section is smaller than the width direction length of the motor housing section. In other embodiments, the width direction length of the circuit housing section may be equal to or greater than the width direction length of the motor housing section.

[0047] In the above embodiment, the drive unit is applied to the main motor of the electric motorcycle. In other embodiments, the drive unit may be applied to a device other than the main motor. Furthermore, the drive unit may be applied to a vehicle other than the electric motorcycle or to a device other than an in-vehicle device.

[0048] It may also be "a drive device as described in any one of items 2 to 5, comprising: a frame member (81) attached to a frame mounting portion (67) provided on the motor housing portion and provided at the end of the housing on the motor housing portion side; and a cover (85) attached to a cover mounting portion (75) provided on the circuit housing portion and provided at the end of the housing on the circuit housing portion side, wherein the frame mounting portion and the cover mounting portion are provided with their axes shifted from each other."

[0049] It may be "the drive device described in any one of items 2 to 6, comprising: a frame member (81) attached to a frame mounting portion (67) provided on the motor housing portion and provided at an end of the housing on the motor housing portion side; and a cover (85) attached to a cover mounting portion (75) provided on the circuit housing portion and provided at an end of the housing on the circuit housing portion side, wherein the frame mounting portion is provided such that, on an imaginary plane perpendicular to the rotation axis of the motor portion, its axis is shifted from a straight line connecting the axis of the cover mounting portion and the rotation axis."

[0050] As described above, the present invention is not limited to the above-described embodiment, and can be embodied in various forms without departing from the spirit of the invention. [Explanation of symbols]

[0051] 10. Drive unit 20 Motor section 21 Motor winding 22 Stator 23 Rotor 25 Shaft 40...Circuit section 41...Circuit board 60. Housing 61 Motor housing section 65 Heat dissipation fin 71 Circuit housing part 81 Frame member 85 Cover 96 Main engine battery (battery)

Claims

1. a motor section (20) having a stator (22) around which motor windings (21) are wound, a rotor (23) that rotates when current is applied to the motor windings, and a shaft (25) that rotates integrally with the rotor; a circuit section (40) having a circuit board (41) on which electronic components (42) relating to current control of the motor windings are mounted; a housing (60) having a motor housing portion (61) for accommodating the motor portion and a circuit housing portion (71) for accommodating the circuit portion, the housing having heat dissipation fins (65) formed on an outer surface thereof; Equipped with A drive device in which the motor housing portion, the circuit housing portion, and the heat dissipation fins are integrally formed.

2. The drive device described in claim 1, wherein the circuit housing portion is provided on one axial side of the cylindrical motor housing portion, and has a connection portion (711) connected to the motor housing portion, and an extension portion (712) extending radially outward from the connection portion of the motor housing portion.

3. If the direction in which the extension portion extends is defined as an extension direction and the direction perpendicular to the extension direction is defined as a width direction, The drive device according to claim 2 , wherein a width direction length of the circuit housing portion is smaller than a width direction length of the motor housing portion.

4. a connector (78) that is connectable to a battery (96) and is provided on the extension portion; The drive device according to claim 2 or 3, wherein the connector is provided within a projection area of ​​the extension portion projected in a motor axial direction.

5. a connector (78) that is connectable to a battery (96) and is provided on the extension portion; The drive device according to claim 2 or 3, wherein the connector is provided so as to protrude outward from a projection area of ​​the extension portion projected in a motor axial direction.

6. a frame member (81) attached to a frame mounting portion (67) provided on the motor housing portion and provided on an end portion of the housing on the motor housing portion side; a cover (85) attached to a cover attachment portion (75) provided on the circuit housing portion and provided on an end portion of the housing on the circuit housing portion side; Equipped with 3. The drive unit according to claim 2, wherein the frame mounting portion and the cover mounting portion are provided with axes offset from each other.

7. a frame member (81) attached to a frame mounting portion (67) provided on the motor housing portion and provided at an end of the housing on the motor housing portion side; a cover (85) attached to a cover attachment portion (75) provided on the circuit housing portion and provided on an end portion of the housing on the circuit housing portion side; Equipped with The drive unit according to claim 2, wherein the frame mounting portion is disposed so that, on an imaginary plane perpendicular to the rotational axis of the motor portion, its axis is offset from a straight line connecting the axis of the cover mounting portion and the rotational axis.

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