Drive unit and its assembly method

Abstract

A drive device and its assembly method are provided, which can improve the positional accuracy of an electric motor relative to a housing. The drive device 1 includes a housing 4 and an electric motor 2 having a motor housing 6 housed within the housing 4. The motor housing 6 has a cylindrical portion 13 and a flange portion 12 extending radially from the open end of the cylindrical portion 13. The housing 4 has a plurality of positioning protrusions 43 and 44 for abutting against the flange portion 12 and an internal thread 45 for fixing the flange portion 12.

Description

Technical Field

[0001] This invention relates to a drive device and a method for assembling the drive device. Background Technology

[0002] Among drive devices that generate the driving force to operate various mechanical devices are those that include electric motors. Electric motors are mostly fixed to the corresponding mechanical device via a housing (casing). For example, an electric motor is fastened to the housing by bolts.

[0003] The housing also contains multiple gears that transmit the rotation of the electric motor to the mechanical device. In this way, a driving force is generated to operate the mechanical device through the drive mechanism.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 6812458 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] Furthermore, in such drive systems, the positional accuracy of the gears and the electric motor is crucial when attempting to improve the efficiency of power transmission from the electric motor to the mechanical device. This is because factors such as gear meshing resistance need to be considered. However, if the goal is simply to fix the electric motor to the housing, the cumulative tolerances of the housing or the electric motor have a significant impact, making it difficult to improve the positional accuracy of the electric motor relative to the housing.

[0009] Therefore, the present invention provides a drive device and a method for assembling the drive device that can improve the positional accuracy of the electric motor relative to the housing.

[0010] Technical means to solve the problem

[0011] To address the aforementioned problem, in a first embodiment of the present invention, the driving device includes: a housing; and an electric motor having a motor housing housed within the housing, the motor housing having: a cylindrical portion; and a flange portion extending radially from the open end of the cylindrical portion, the housing having: a plurality of positioning protrusions for abutting the flange portion; and a fixing portion for fixing the flange portion.

[0012] This configuration minimizes the contact area between the housing and the electric motor (motor housing). Therefore, the cumulative tolerances between the housing and the electric motor can be minimized in terms of the positional accuracy of the electric motor relative to the housing. Furthermore, by reducing the contact area between the electric motor and the housing, the accuracy of this contact area (flatness, etc.) can be easily improved. Thus, the positional accuracy of the electric motor relative to the housing can be improved.

[0013] In a second aspect of the invention, according to the driving device of the first aspect, the fixing portion may be formed on the abutting surface of the positioning protrusion and the flange portion.

[0014] This configuration further reduces the contact area between the housing and the electric motor. Furthermore, it allows for easy fixation of the electric motor to the housing while the flange abuts against the locating protrusion. Therefore, it easily improves the positional accuracy of the electric motor relative to the housing.

[0015] In a third embodiment of the invention, according to the driving device of the first or second embodiment, a fastener may be fixed to the fixed portion, and the flange portion has a fastener insertion hole through which the fastener is inserted.

[0016] With this configuration, the electric motor can be easily positioned radially relative to the housing using the fastener and the fastener insertion hole.

[0017] In the fourth aspect of the present invention, according to the driving device of any one of the first to third aspects, the housing may have a receiving recess for receiving the motor housing, and the motor housing is fitted into the receiving recess with a radial gap formed between it and the receiving recess.

[0018] This configuration allows for fine-tuning of the electric motor's position while it is housed within the casing. Therefore, positioning the electric motor relative to the casing is facilitated.

[0019] In the fifth aspect of the present invention, according to the driving device of the third aspect, the motor housing may be formed by pressing a metal plate, the fastener insertion hole may be formed by punching the flange portion through the pressing process, and burrs generated around the periphery of the fastener insertion hole protrude toward the opposite side of the positioning protrusion.

[0020] This configuration allows the flange to be tightly fitted to the locating protrusion. Therefore, the positional accuracy of the electric motor relative to the housing can be further improved.

[0021] In the sixth aspect of the present invention, the assembly method of the drive device is as follows: the drive device includes: a housing having a receiving recess; and an electric motor having a motor housing received in the receiving recess, the motor housing having: a cylindrical portion; and a flange portion extending radially from the open end of the cylindrical portion; the housing having: a plurality of positioning protrusions for the flange portion to abut against; and a fixing portion for fixing the flange portion; the assembly method includes: a receiving step, using a clamp to grip the motor shaft of the electric motor and receiving the electric motor in the receiving recess; a flange pressing step, after the receiving step, pressing the periphery of the portion of the flange portion corresponding to the positioning protrusions from above to push the flange portion to the positioning protrusions; and a fixing step, after the flange pressing step, using the fixing portion to fix the flange portion.

[0022] By adopting this method, it is possible to easily fine-tune the electric motor when assembling it into the housing while minimizing the contact area between the housing and the electric motor (motor housing). Therefore, the positional accuracy of the electric motor relative to the housing can be improved.

[0023] In the seventh aspect of the present invention, according to the assembly method of the drive device of the sixth aspect, a fastener fixed to the fixed part may be provided, the flange part has a fastener insertion hole for the fastener to be inserted, the motor housing is formed by pressing a metal plate, and the punching direction when forming the fastener insertion hole is from the side of the abutment surface of the positioning protrusion toward the side opposite to the abutment surface of the positioning protrusion.

[0024] By using this method, the flange can be tightly fitted to the locating protrusion.

[0025] Therefore, it is possible to further improve the positional accuracy of the electric motor relative to the housing.

[0026] The effects of the invention

[0027] According to the present invention, the positional accuracy of the electric motor relative to the housing can be improved. Attached Figure Description

[0028] [ Figure 1 [Illustration 1] is a cross-sectional view of the driving device in an embodiment of the present invention.

[0029] [ Figure 2 [Illustration 1] is an exploded perspective view of the driving device in an embodiment of the present invention.

[0030] [ Figure 3 [Illustration] is an explanatory diagram showing the shape of a portion of the flange in an embodiment of the present invention.

[0031] [ Figure 4 [This is a plan view of the drive device in the embodiment of the present invention viewed from above.] Detailed Implementation

[0032] The embodiments of the present invention will now be described with reference to the accompanying drawings.

[0033] <Driver>

[0034] Figure 1 This is a cross-sectional view of drive unit 1. Figure 2 This is an exploded perspective view of drive unit 1.

[0035] The drive unit 1 is, for example, a device that serves as a power source for starting the engine (prime mover) of a two-wheeled or four-wheeled vehicle. The drive unit 1 is, for example, located in a power unit (not shown). The power unit is an integrated unit comprising the engine and a transmission (not shown). For example, in a two-wheeled vehicle, the power unit is connected to the rear wheel via a chain drive mechanism.

[0036] like Figure 1 , Figure 2 As shown, the drive unit 1 includes: two electric motors 2, a bracket 3 integrally holding the two electric motors 2, and a housing 4 for housing the two electric motors 2. The two electric motors 2 are arranged side-by-side. The two electric motors 2 are arranged symmetrically about the center between them. The two electric motors 2 have the same structure. Therefore, in the following description, only one of the two electric motors 2 will be described, and the description of the other will be omitted. The two electric motors 2 are labeled with the same symbols.

[0037] <Electric Motor>

[0038] The electric motor 2 is a so-called brushed motor. The electric motor 2 includes: an armature 5, and a motor housing 6 that rotatably houses the armature 5. The armature 5 includes: a motor shaft 7, an armature core 8 fitted and fixed to the motor shaft 7, and a commutator 9 fitted and fixed to the motor shaft 7.

[0039] In the following description, the axial direction of motor shaft 7 will be referred to simply as the axial direction. The radial direction of motor shaft 7 will be referred to simply as the radial direction. The direction of rotation of armature 5, that is, the direction around motor shaft 7, will be referred to as the circumferential direction.

[0040] A coil (not shown) is wound around the armature core 8. The end of the coil is connected to a commutator 9. The commutator 9 has a plurality of conductive commutator segments 9a. The commutator segments 9a are arranged at predetermined intervals in the circumferential direction. This commutator 9 is arranged side by side with the armature core 8 in the axial direction. Hereinafter, in the axial direction, the armature core 8 side is sometimes referred to as the lower side, and the commutator 9 side is referred to as the upper side.

[0041] The motor housing 6 has a bottomed cylindrical yoke 11 and a flange 12 integrated with the yoke 11. The yoke 11 has an axially centered cylindrical portion 13 and a bottom 14 formed at the lower end of the cylindrical portion 13. A permanent magnet 23 is provided on the inner circumferential surface of the cylindrical portion 13. The permanent magnet 23 faces the armature core 8 radially.

[0042] A downwardly protruding bearing boss 14a is formed at the bottom 14. A bearing 15 is provided on the bearing boss 14a. The bearing 15 rotatably supports the lower end 7a of the motor shaft 7.

[0043] The flange portion 12 is formed by pressing a metal sheet to close the opening 13a of the cylindrical portion 13. The flange portion 12 is formed to extend radially from the opening 13a of the cylindrical portion 13. When viewed from the axial direction, the flange portion 12 is pentagonal in shape.

[0044] That is, when viewed from the axial direction, the flange portion 12 has: a bottom edge portion 12a, two side edges 12b extending from both ends of the bottom edge portion 12a in a direction orthogonal to the bottom edge portion 12a, and two inclined edges 12c extending obliquely from the ends of the side edges 12b on the side opposite to the bottom edge portion 12a. The ends of the two inclined edges 12c on the side opposite to the side edges 12b are connected to each other.

[0045] Therefore, two bottom-side corner portions 12d are formed between the bottom edge portion 12a and the side edge portion 12b. Two oblique-side corner portions 12e are formed between the side edge portion 12b and the oblique edge portion 12c.

[0046] A vertex portion 12f is formed at the junction of the two hypotenuse portions 12c.

[0047] Figure 3 This is an explanatory diagram illustrating the shape of a portion of flange 12. Figure 3 In order to make the explanation easier to understand, the scale has been appropriately changed.

[0048] like Figures 1 to 3 As shown, bottom bolt insertion holes 18a are formed at the two bottom corners 12d of the flange portion 12. A vertex bolt insertion hole 18b is formed at the vertex portion 12f of the flange portion 12.

[0049] Each bolt insertion hole 18a and 18b is formed into the same shape through the same processing. Each bolt insertion hole 18a and 18b is formed by punching the flange portion 12. The punching direction D is from the lower surface 12g on the side of the yoke portion 11 of the flange portion 12 toward the upper surface 12h on the opposite side of the lower surface 12g of the flange portion 12. Therefore, burrs 24 generated around the periphery of each bolt insertion hole 18a and 18b during the formation of these bolt insertion holes 18a and 18b protrude from the upper surface 12h toward the opposite side (above) of the yoke portion 11.

[0050] Bolts 10, used to fix the flange 12 (motor housing 6) to the housing 4, are inserted into the bolt holes 18a and 18b.

[0051] A bearing boss 16 protruding axially outward is provided at the center of the flange portion 12 when viewed from the axial direction. A through hole 16b is formed at the bottom 16a of the bearing boss 16. The upper end 7b of the motor shaft 7 is inserted through the through hole 16b. A bearing 17 is provided on the bearing boss 16. The bearing 17 provides rotatable support for the upper end 7b of the motor shaft 7. The upper end 7b of the motor shaft 7 protrudes outward through the through hole 16b of the bearing boss 16. A pinion 19 is fitted and fixed at the protruding portion.

[0052] A brush holder 20 is provided on the lower surface 12g of the flange portion 12 on the side of the yoke portion 11. A brush (not shown) is held in the brush holder 20, which slides against the commutator segment 9a. Two terminal holding portions 21a and 21b (first terminal holding portion 21a and second terminal holding portion 21b) are integrally formed on the brush holder 20, protruding from the upper surface 12h opposite to the lower surface 12g of the flange portion 12. The two terminal holding portions 21a and 21b are arranged facing each other on both sides, separated by the fitting cylindrical portion 32 of the flange portion 12.

[0053] More specifically, the first terminal holding portion 21a of the two terminal holding portions 21a and 21b is disposed between the two bottom bolt insertion holes 18a. The distance from the first terminal holding portion 21a to the bottom edge portion 12a is longer than the distance from the bottom bolt insertion holes 18a to the bottom edge portion 12a. That is, the first terminal holding portion 21a is disposed closer to the bearing boss 16 than the bottom bolt insertion holes 18a. The second terminal holding portion 21b of the two terminal holding portions 21a and 21b is disposed between the top bolt insertion hole 18b and the bearing boss 16.

[0054] Terminals 22 are inserted into each of the terminal holding portions 21a and 21b. A brush (not shown) is connected to the lower end of each terminal 22. A wire harness (not shown) extending from an external power source is connected to the upper end of each terminal 22.

[0055] Based on this structure, power from an external power source is supplied to the brushes via terminal 22. The power supplied to the brushes is then supplied to a coil (not shown) via commutator 9. This generates a predetermined magnetic field in the armature core 8, creating a magnetic attraction or repulsion force between the armature core 8 and the permanent magnet 23 of the yoke 11. As a result, the armature 5 continues to rotate.

[0056] Since the two electric motors 2 are arranged symmetrically with respect to the center between them, their motor shafts 7 are parallel. The bottom edges 12a of the flange portions 12 of the two electric motors 2 face each other. A spur gear (not shown) of a power unit is disposed between each pinion 19 of the two electric motors 2. Each pinion 19 meshes with the spur gear, and the power of the drive device 1 is transmitted to the power unit.

[0057] <Staff>

[0058] Figure 4 This is a plan view of the drive unit 1 viewed from above.

[0059] like Figure 1 , Figure 2 , Figure 4 As shown, the support 3 is formed of resin. The support 3 has: a plate-shaped base portion 31, and two fitting cylindrical portions 32 integrally formed with the base portion 31. Bearing bosses 16 of the electric motor 2 are respectively fitted into the two fitting cylindrical portions 32.

[0060] That is, the bracket 3 has the function of temporarily positioning each electric motor 2.

[0061] The base portion 31 is formed spanning the two fitting cylindrical portions 32 in a manner that integrates the two fitting cylindrical portions 32. More specifically, the base portion 31 is formed, when viewed from the axial direction, in the arrangement direction of the two electric motors 2 ( Figure 1 , Figure 2 , Figure 4 The base portion 31 is a rectangular shape that extends along its length (left-right direction). Hereinafter, the direction of the longer side of the base portion 31 when viewed axially will be referred to as the X direction. The direction of the shorter side of the base portion 31 will be referred to as the Y direction.

[0062] The base portion 31 extends between the second terminal holding portions 21b of the two electric motors 2. That is, the periphery of the apex-side bolt insertion hole 18b in the flange portion 12 of the motor housing 6 is located further outward than the two sides of the bracket 3 in the X direction. Therefore, when the bracket 3 is viewed from above, the portion of the flange portion 12 from the beveled side corner portion 12e to the apex portion 12f is exposed.

[0063] The base portion 31 has a terminal through hole 33 through which each first terminal holding portion 21a is inserted when two electric motors 2 are assembled. The first terminal holding portion 21a protrudes to the stop through the terminal through hole 33.

[0064] On both sides of the base portion 31 in the X direction, when two electric motors 2 are mounted, terminal recesses 34 are formed corresponding to the portions of each second terminal holding portion 21b. The second terminal holding portion 21b protrudes in the stop direction via the terminal recesses 34.

[0065] On one of the two sides in the Y direction of the base portion 31 ( Figure 4 Above the bolt insertion hole 18a on the bottom side, when two electric motors 2 are installed, a bolt insertion opening 35 is formed at the location corresponding to the bolt insertion hole 18a on the bottom side. Clamp insertion openings 36 are formed on the base part 31 at two positions further outward in the X direction than the bolt insertion opening 35.

[0066] On the other side of the two sides in the Y direction of the base portion 31 ( Figure 4 (Below) When two electric motors 2 are assembled, a mounting recess 37 is formed corresponding to and around the bottom bolt insertion hole 18a. The mounting recess 37 has: a bolt insertion recess 37a formed at the location corresponding to the bottom bolt insertion hole 18a, and a clamping recess 37b formed at a position further outward in the X direction than the bolt insertion recess 37a. These bolt insertion recesses 37a and clamping recesses 37b communicate with each other. The depth of the bolt insertion recess 37a in the Y direction is greater than the depth of the clamping recess 37b in the Y direction.

[0067] Thus, by inserting the bolt through the opening 35, the clamp through the opening 36, and the mounting recess 37, when the bracket 3 is viewed from above, the bottom bolt through hole 18a and the portion on the X-direction vertex 12f side, which is closer to the bottom bolt through hole 18a, are exposed.

[0068] Furthermore, a plurality of wire harness holding claws 38 are formed on the upper surface 31a of the base portion 31 on the side opposite to the electric motor 2. The wire harness holding claws 38 hold wire harnesses (not shown) connected to the terminals 22 of the electric motor 2. In addition, a plurality of motor engaging claws 39 (four in this embodiment) protruding downward are formed on both sides of the base portion 31 in the Y direction. The bracket 3 engages with the flange portion 12 of the electric motor 2 through the motor engaging claws 39.

[0069] <Shell>

[0070] The housing 4 has a block 40, which has two receiving recesses 41 for housing the electric motor 2. Each receiving recess 41 has a receiving opening 41a at its upper part. When viewed axially, it is formed in a circular shape corresponding to the cylindrical portion 13 constituting the yoke portion 11 of the electric motor 2. The inner circumferential surface of the receiving recess 41 is slightly tapered, with its inner diameter gradually increasing from the receiving bottom 41b towards the receiving opening 41a, i.e., it gradually expands. The entire yoke portion 11 is housed within this receiving recess 41.

[0071] The inner diameter of the receiving recess 41 on the receiving bottom 41b side is slightly larger than the outer diameter of the cylindrical portion 13 of the magnetic yoke 11. A bearing receiving recess 47 is formed on the receiving bottom 41b to receive the bearing boss 14a of the magnetic yoke 11. The bearing receiving recess 47 is also formed in a circular shape when viewed from the axial direction, corresponding to the bearing boss 14a. The inner diameter of the bearing receiving recess 47 is slightly larger than the outer diameter of the bearing boss 14a. Therefore, the electric motor 2 is fitted into the receiving recess 41 with a radial gap. Therefore, the electric motor 2 can move slightly in the XY direction when it is received in the receiving recess 41.

[0072] A cylindrical portion 42 is formed on the upper surface 40a of the block 40 on the side of the receiving opening 41a, extending from the side of the block 40. A cylindrical opening 42a is formed on the side of the cylindrical portion 42 opposite to the block 40.

[0073] On the upper surface 40a of the block 40 and the inner surface 42b of the cylindrical portion 42, a plurality of (six in this embodiment) positioning protrusions 43 and 44 (bottom side positioning protrusion 43 and top side positioning protrusion 44) are formed in such a way as to engage with these upper surface 40a and inner surface 42b.

[0074] The bottom positioning protrusion 43 of the positioning protrusions 43 and 44 is formed at the location corresponding to the bottom bolt insertion hole 18a of the flange portion 12. Each bottom positioning protrusion 43 is circular when viewed from the axial direction. Adjacent bottom positioning protrusions 43 in the X direction are integrated with each other. Therefore, the two bottom positioning protrusions 43 form an elliptical shape when viewed from the axial direction.

[0075] The apex-side positioning protrusions 44 of the positioning protrusions 43 and 44 are formed at the locations corresponding to the apex-side bolt insertion holes 18b of the flange portion 12. Each apex-side positioning protrusion 44 is circular when viewed from the axial direction. The upper surfaces 43a and 44a of each positioning protrusion 43 and 44 are formed flatly along the XY direction.

[0076] The portion surrounding the bottom bolt insertion hole 18a of the flange portion 12 is mounted on the upper surface 43a of the bottom positioning protrusion 43. The portion surrounding the apex bolt insertion hole 18b of the flange portion 12 is mounted on the upper surface 44a of the apex positioning protrusion 44. Thus, each upper surface 43a, 44a becomes the contact surface with the flange portion 12. As for the housing 4, the lower surface 12g of the flange portion 12 is in contact only with each upper surface 43a, 44a. That is, the flange portion 12 of each electric motor 2 only contacts the three corresponding positioning protrusions 43, 44.

[0077] Internal thread portions 45 for bolts 10 to be threaded are formed on each of the upper surfaces 43a and 44a. After the flange portion 12 is placed on the upper surfaces 43a and 44a of the locating protrusions 43 and 44, the bolts 10 are threaded into the bolt insertion holes 18a and 18b at each internal thread portion 45. This secures each flange portion 12 (electric motor 2) to the housing 4. In other words, the internal thread portion 45 functions as a fixing part for fixing the flange portion 12 to the housing 4. Details regarding the assembly method of the drive device 1 will be described later.

[0078] <Assembly method of drive unit>

[0079] Next, the assembly method of the drive unit 1 will be described.

[0080] First, after assembling the electric motor 2, the bearing boss 16 of the electric motor 2 is fitted into the fitting cylindrical portion 32 of the bracket 3. Then, the motor engaging claw 39 of the bracket 3 is engaged with the flange portion 12. Thus, the bracket 3 and the two electric motors 2 are temporarily fixed and integrated.

[0081] Next, using a tool not shown, grasp the exposed portion of the motor shaft 7 of each electric motor 2 between the bearing boss 16 and the pinion 19. Then, with the bottom 14 of the magnetic yoke 11 facing the storage opening 41a of the housing 4, directly store the electric motor 2 in the storage recess 41 (storage process).

[0082] Then, the flange portion 12 is placed on the upper surfaces 43a and 44a of each positioning protrusion 43, 44. Here, burrs 24 generated at the periphery of each bolt insertion hole 18a, 18b during the formation of these bolt insertion holes protrude from the upper surface 12h of the flange portion 12 toward the opposite side (above) of the magnetic yoke portion 11. Therefore, the flange portion 12 is in close contact with the upper surfaces 43a and 44a of each positioning protrusion 43, 44.

[0083] During the storage process, since the motor shaft 7 is directly gripped using a tool not shown, the dimensions between the motor shafts 7 of the two electric motors 2 are determined with high precision regardless of the manufacturing errors of each electric motor 2. Furthermore, the electric motor 2 is fitted into the storage recess 41 with a radial clearance. Therefore, the electric motor 2 can move slightly in the XY direction while stored in the storage recess 41. Thus, the electric motor 2 can move slightly in the X direction. Consequently, manufacturing errors of the electric motor 2 or the housing 4 can be absorbed by the storage recess 41.

[0084] As a result, with the dimensions between the motor shafts 7 of the two electric motors 2 maintained at a high precision, the electric motors 2 are respectively housed in the housing recesses 41.

[0085] Then, using the pressing tool 50 (see...) Figure 4 Press the flange 12 from above onto the periphery of the portion corresponding to the positioning protrusions 43 and 44. Then, push the flange 12 onto each positioning protrusion 43 and 44 (pressing process).

[0086] The periphery of the flange portion 12 corresponding to the positioning protrusions 43 and 44 refers to the part of the flange portion 12 that is exposed when the bracket 3 is viewed from above.

[0087] Specifically, the pressing tool 50 is inserted into the clamping through opening 36 of the bracket 3, and simultaneously inserted into the clamping through recess 37b to press the flange portion 12. As a result, the bottom corner portion 12d of the flange portion 12 is pushed to the bottom positioning protrusion 43.

[0088] Additionally, the pressing tool 50 presses down on both sides of the flange portion 12f in the Y direction, across the bolt insertion hole 18b on the vertex side. As a result, the vertex portion 12f of the flange portion 12 is pushed against the vertex side positioning protrusion 44.

[0089] After the pressing process, the internal threaded portion 45 of each positioning protrusion 43, 44 and each bolt insertion hole 18a, 18b are approximately coaxial.

[0090] Then, with the flange 12 pressed against each positioning protrusion 43, 44, bolts 10 are screwed onto each internal thread 45 through bolt insertion holes 18a, 18b from the flange 12. This secures each flange 12 (electric motor 2) to the housing 4 (fixing process). The assembly of the drive unit 1 is then complete.

[0091] Thus, in the drive unit 1, the electric motor 2 has a flange portion 12 extending radially from the cylindrical portion 13. The housing 4 has a plurality of positioning protrusions 43, 44 for abutting against the flange portion 12, and an internally threaded portion 45 serving as a fixing portion. Therefore, the contact area between the housing 4 and the flange portion 12 (electric motor 2) can be minimized as much as possible. As a result, the cumulative error between the housing 4 and the electric motor 2 can be minimized as much as possible in terms of the positional accuracy of the electric motor 2 relative to the housing 4. In addition, since the contact area between the electric motor 2 and the housing 4 can be reduced, the accuracy (flatness, etc.) of the contact area can be easily improved. That is, only the upper surfaces 43a and 44a of the positioning protrusions 43 and 44 need to be machined with high precision, for example, the flatness. Therefore, the positional accuracy of the electric motor 2 relative to the housing 4 can be easily and reliably improved. Furthermore, for example, by appropriately meshing the drive unit 1 with the spur gear of the power unit (not shown), the drive transmission efficiency from the drive unit 1 to the power unit can also be improved.

[0092] The internal thread portion 45, which serves as the fixing part, is not formed as a separate fixing surface independent of each positioning protrusion 43, 44. By forming the internal thread portion 45 on each positioning protrusion 43, 44, it serves as both the positioning protrusion 43, positioning protrusion 44 and the fixing part. Therefore, the contact area between the housing 4 and the flange portion 12 can be reliably reduced. Moreover, the electric motor 2 can be easily fixed to the housing 4 while the flange portion 12 abuts against each positioning protrusion 43, 44. Therefore, the positional accuracy of the electric motor 2 relative to the housing 4 can be easily improved.

[0093] Bolts 10 are used to fix the electric motor 2 to the housing 4. The flange portion 12 of the electric motor 2 has bottom bolt insertion holes 18a and top bolt insertion holes 18b for inserting the bolts 10. Therefore, by inserting the bolts 10 into each bolt insertion hole 18a, 18b and screwing the bolts 10 into the internal thread portion 45, the electric motor 2 can be easily positioned radially relative to the housing 4. Thus, the positional accuracy of the electric motor 2 relative to the housing 4 can be easily improved.

[0094] The electric motor 2 is fitted into the receiving recess 41 with a radial gap between it and the receiving recess 41. Therefore, the electric motor 2 can move slightly in the XY direction while being housed in the receiving recess 41. That is, the position of the electric motor 2 can be finely adjusted while it is housed in the housing 4. Therefore, positioning of the electric motor 2 relative to the housing 4 can be facilitated.

[0095] The bolt insertion holes 18a and 18b formed in the flange portion 12 are formed by pressing and stamping the flange portion 12. The stamping direction D is from the lower surface 12g on the side of the yoke portion 11 of the flange portion 12 toward the upper surface 12h on the opposite side of the lower surface 12g of the flange portion 12. Therefore, burrs 24 generated around the bolt insertion holes 18a and 18b during the formation of the bolt insertion holes 18a and 18b protrude from the upper surface 12h toward the opposite side (above) of the yoke portion 11. As a result, when the flange portion 12 is placed on the upper surfaces 43a and 44a of the positioning protrusions 43 and 44, the flange portion 12 can be tightly fitted to the upper surfaces 43a and 44a of the positioning protrusions 43 and 44. Therefore, the positional accuracy of the electric motor 2 relative to the housing 4 can be further improved.

[0096] The assembly method for the drive device 1 includes: a storage step, in which the electric motor 2 is stored in the storage recess 41; a flange pressing step, in which the flange 12 is pressed against the positioning protrusions 43 and 44 after the storage step; and a fixing step, in which the flange 12 is fixed to the housing 4 by bolts 10 after the flange pressing step. Therefore, it is possible to easily fine-tune the electric motor 2 when assembling it into the housing 4 while minimizing the contact area between the housing 4 and the electric motor 2 (motor housing 6). Therefore, the positional accuracy of the electric motor 2 relative to the housing 4 can be improved.

[0097] Because it can improve the positional accuracy of the electric motor 2 relative to the housing 4, and also improve, for example, the drive transmission efficiency from the drive unit 1 to the power unit, it can contribute to the United Nations-led Sustainable Development Goals (SDGs) Goal 7 "Ensuring access to affordable, reliable and sustainable modern energy for all", Goal 9 "Building resilient infrastructure, promoting inclusive and sustainable industrialization and driving innovation", and Goal 12 "Ensuring sustainable production and consumption patterns".

[0098] This invention is not limited to the embodiments described herein, but includes various modifications made to the embodiments without departing from the spirit of this invention.

[0099] For example, in the described embodiment, the electric motor 2 is a so-called brushed motor. However, it is not limited to this and may also be a so-called brushless motor.

[0100] In the described embodiment, the flange portion 12 of the electric motor 2 is described as having a pentagonal shape when viewed from the axial direction. The contact between the three positioning protrusions 43 and 44 of the housing 4 and one flange portion 12 is also described. However, this is not a limitation; the shape of the flange portion 12 can be arbitrarily determined. The number of positioning protrusions can be multiple.

[0101] In the described embodiment, the case where an internal threaded portion 45 serving as a fixing portion is formed in each positioning protrusion 43, 44 has been explained. However, it is not limited to this, and a fixing seat surface may be provided independently of each positioning protrusion 43, 44, and the internal threaded portion 45 may be formed on the fixing seat surface.

[0102] In the described embodiment, the case where the flange 12 is fixed to the housing 4 using an internally threaded portion 45 as a fixing part and a bolt 10 as a fastener fixed to the internally threaded portion 45 is explained. However, this is not a limitation, and various forms can be used for the fixing part and the fastener. For example, a retaining pin can be used instead of the bolt 10 as a fastener. In this case, a retaining hole for pressing the retaining pin into can be used instead of the internally threaded portion 45 as the fixing part.

[0103] In the described embodiment, the drive unit 1 includes two electric motors 2. However, it is not limited to this; there may be one or more electric motors 2. Even in such cases, the structure described above can improve the positional accuracy of the electric motors 2 relative to the housing 4.

[0104] Explanation of icon numbers

[0105] 1: Drive unit

[0106] 2: Electric motor

[0107] 3: Bracket

[0108] 4: Casing

[0109] 5: Armature

[0110] 6: Motor housing

[0111] 7: Motor shaft

[0112] 7a: Lower end

[0113] 7b: Upper end

[0114] 8: Armature core

[0115] 9: Commutator

[0116] 9a: Commutator segment

[0117] 10: Bolts

[0118] 11: Magnetic yoke

[0119] 12: Flange section

[0120] 12a: Bottom edge

[0121] 12b: Side section

[0122] 12c: Hypotenuse

[0123] 12d: Bottom corner

[0124] 12e: Lateral angle of hypotenuse

[0125] 12f: Vertex

[0126] 12g: lower surface

[0127] 12h: Upper surface

[0128] 13: Cylinder section

[0129] 13a: Opening

[0130] 14: Bottom

[0131] 14a: Bearing boss

[0132] 15: Bearings

[0133] 16: Bearing boss

[0134] 16a: Bottom

[0135] 16b: Through hole

[0136] 17: Bearings

[0137] 18a: Bottom side bolt insertion hole

[0138] 18b: Through hole for bolts on the apex side

[0139] 19: Small gear

[0140] 20: Brush holder

[0141] 21a: First terminal holding part

[0142] 21b: Second terminal holding part

[0143] 22: Terminal

[0144] 23: Permanent magnet

[0145] 24: Burrs

[0146] 31: Base section

[0147] 31a: Upper surface

[0148] 32: Fitting cylindrical part

[0149] 33: Terminal through hole

[0150] 34: Terminal recess

[0151] 35: Bolt inserted through the opening

[0152] 36: Fixture insertion opening

[0153] 37: Assembly recess

[0154] 37a: Bolt inserted through the recess

[0155] 37b: Clamp insertion recess

[0156] 38: Harness retaining claw

[0157] 39: Motorca jaws

[0158] 40: Block

[0159] 40a: Upper surface

[0160] 41: Storage recess

[0161] 41a: Storage opening

[0162] 41b: Storage bottom

[0163] 42: Cylinder section

[0164] 42a: Opening of the cylinder section

[0165] 42b: Inner surface

[0166] 43: Positioning the convex part

[0167] 43a: Upper surface

[0168] 44: Positioning the convex part

[0169] 44a: Upper surface

[0170] 45: Internal thread section

[0171] 47: Bearing storage recess

[0172] 50: Pressing tool

[0173] D: Punching direction

[0174] X: Long side direction

[0175] Y: Short side direction

Claims

1. A driving device, characterized in that... include: case; as well as An electric motor having a motor housing housed within the housing. The motor housing has: cylindrical part; as well as The flange extends radially from the open end of the cylindrical section. The housing has: Multiple positioning protrusions for the flange portion to abut; and A fixing part is used to fix the flange part.

2. The driving device according to claim 1, characterized in that, The fixing part is formed on the contact surface between the positioning protrusion and the flange.

3. The driving device according to claim 1 or 2, characterized in that, It has a fastener that is fixed to the fixed part. The flange portion has a fastener insertion hole for the fastener to be inserted.

4. The driving device according to claim 1 or 2, characterized in that, The housing has a recessed portion for receiving the motor housing. The motor housing is fitted into the receiving recess with a radial gap between it and the receiving recess.

5. The driving device according to claim 3, characterized in that, The motor housing is formed by pressing a metal sheet. The fastener insertion hole is formed by punching the flange portion through the pressing process. The burrs generated around the periphery of the fastener insertion hole protrude to the opposite side of the positioning protrusion.

6. A method for assembling a drive device, the drive device comprising: The casing has a recessed area for storage; as well as An electric motor having a motor housing housed within the receiving recess. The motor housing has: cylindrical part; as well as The flange extends radially from the open end of the cylindrical section. The housing has: Multiple positioning protrusions are provided for the flange portion to abut against; as well as The fixing part is used to fix the flange part. The assembly method of the drive device is characterized by including: In the storage process, a clamp is used to hold the motor shaft of the electric motor and store the electric motor in the storage recess. In the flange pressing process, after the storage process, the flange portion is pressed from above, around the periphery of the portion corresponding to the positioning protrusion, pushing the flange portion towards the positioning protrusion; and In the fixing process, after the pressing process of the flange part, the flange part is fixed using the fixing part.

7. The assembly method of the drive device according to claim 6, characterized in that, It has a fastener that is fixed to the fixed part. The flange portion has a fastener insertion hole for the fastener to be inserted. The motor housing is formed by pressing a metal sheet. The punching direction when forming the through hole of the fastener is from the side of the abutment surface of the positioning protrusion toward the side opposite to the abutment surface of the positioning protrusion.

Images