JP6732482B2 - Motor unit - Google Patents

Description

The present invention relates to a motor unit that houses a motor having a rotating shaft in a case (housing).

2. Description of the Related Art Conventionally, for example, in a vehicle-related device, a motor having a rotating shaft is housed in a case and used as a unit in various motor-driven devices (eg, electric seat recliner, electric lumbar support device, electric seat slide device). Is being done.

In such a motor unit, it is inevitable that sound and vibration are generated during driving. Sound and vibration are particularly problematic in luxury cars. Japanese Patent Application Laid-Open Publication No. 2004-242242 proposes a holder (case) for accommodating a motor and a motor yoke, using magnetic noise generated from the yoke of the motor as a problem.

JP, 2015-76915, A

However, the motor unit of Patent Document 1 can prevent radial vibration and sound by the press-fitting portion of the yoke, but does not take preventive measures against axial vibration and sound.

According to the present invention, in a motor unit having a case for accommodating and supporting a motor having an output shaft in a case, vibration and sound in the radial direction (radial direction) and the axial direction (thrust direction) are generated in the radial direction of the output shaft and the case. An object of the present invention is to obtain a motor unit that can be prevented without sacrificing axial position accuracy.

According to the present invention, in a motor unit having a motor having an output shaft protruding from an end of a motor body and a case for housing and supporting the motor, the motor unit is interposed between the motor body and the case in a direction parallel to the output shaft. a thrust elastic member, have a radial elastic member interposed in a radial direction of the output shaft, comprising a composite elastic member in which the thrust elastic member and the radial elastic member is integrally molded, composite elastic which is the integrally molded The member includes a radial elastic member fitted to the outer periphery of the motor body, a thrust elastic member fitted to a bearing boss projectingly formed at an axial end of the motor body, the radial elastic member and the thrust elastic member. And a connecting portion having a thickness smaller than the axial length of the thrust elastic member .

It is preferable that a pair of the thrust elastic members are provided on one end side and the other end side of the motor main body so as to be axially separated from each other.

The pair of thrust elastic members may have a radial gap between the thrust elastic members and the case.

It is preferable that at least a part of the pair of thrust elastic members overlap each other when viewed from the output shaft direction.

The axial lengths of the pair of thrust elastic members may be different from each other.

In the motor unit of the present invention, the motor and the case may have a non-circular shape in a cross section orthogonal to the axis.

Motor unit of the present invention, between the motor and the case, possess a thrust elastic member interposed output shaft in a direction parallel to Lula dialkyl elastic member be interposed in the radial direction of the output shaft, the thrust elastic member Since the integrally formed composite elastic member including the radial elastic member is used , play of the motor in the case can be prevented and sound and vibration can be prevented without impairing the assembling property of the motor and the case.

It is an exploded perspective view showing one embodiment of a motor unit by the present invention. FIG. 2 is an exploded perspective view showing an embodiment of a motor unit according to the present invention, as viewed from a direction opposite to FIG. 1. FIG. 3 is a plan view of an assembled state showing an embodiment of the motor unit according to the present invention. FIG. 4 is a sectional view taken along the line IV-IV of FIGS. 1 and 2 in an assembled state of the motor unit of FIGS. 1 to 3. FIG. 5 is a sectional view taken along the line VV of FIGS. 1 to 3 in an assembled state of the motor unit of FIGS. 1 to 3. 5 is an enlarged sectional view showing a thrust elastic member for supporting the front end portion of the motor body of FIG. 4 in a thrust direction and a peripheral structure thereof. FIG. FIG. 6 is an enlarged cross-sectional view showing an embodiment of the structure of a shaft end pressing member that bears the tip of the rotary shaft of the motor unit in the thrust direction.

The figure shows an embodiment of a motor unit 100 according to the invention. 1 and 2 show all elements of the motor unit 100 in a disassembled state, and FIGS. 3 to 5 show a state in which the motor 10 is housed in a case 20. The motor 10 is rotated by the motor 10. The case 20 is provided with a reduction mechanism including the driven feed screw shaft 11, a thrust elastic member 30, and a composite elastic member 40. The motor 10 has a rotating shaft (output shaft) 10b protruding from one end of a motor body (housing and yoke) 10a. Hereinafter, the "shaft (thrust) direction" means the axial direction of the rotating shaft 10b. The “radial direction” means a radial direction from the rotating shaft 10b. The front end side of the rotating shaft 10b of the motor body 10a is the front, and the front, rear, upper, and lower directions are the directions shown in the figure.

The motor body 10a has a non-circular outer shape in a cross section orthogonal to the axis (a cross section orthogonal to the axis) (a rectangular tube shape having four semi-cylindrical corners). In the motor body 10a, one end portion in the axial direction and both end portions of the other end portion (front end portion (front bracket) 10a1 and rear end portion (end bracket) 10a2) are positioned on the same axis line, Bearing bosses (circular protrusions) 10c (FIGS. 4 and 5) and 10d are formed, and the rotary shaft 10b penetrates the bearing bosses 10c and 10d and projects on the axis thereof. A worm 13 is fixed to a tip portion of the rotary shaft 10b protruding from the bearing boss 10c. The motor body 10a includes a power supply terminal 10e protruding from an end on the bearing boss 10d side that supports the rear end of the rotary shaft 10b. The motor 10 drives the rotary shaft 10b in the forward and reverse directions by energizing it through the power supply terminal 10e, and its configuration is not limited. 4 and 5, the internal structure of the motor 10 is omitted.

The case 20 includes a tubular body 21, a lid 22, and a gear portion lid 23. The tubular body 21 has an open portion 21b at the rear end of the tubular portion 21a and a gear holding portion 21c at the front end. The tubular portion 21a has a non-circular closed curve shape in which a cross section (transverse cross section) orthogonal to the rotating shaft 10b of the housed motor 10 is a non-circular closed curve shape, that is, an integral shape without seams or cracks. The inner shape of the tubular portion 21a is a non-circular shape (square tubular shape with four corners having a semi-cylindrical shape) corresponding to the motor body 10a, and three screw seats 21b1 are formed on the end surface of the open portion 21b. Has been done.

In the cylindrical portion 21a, a lid step portion 21b2 and an elastic member step portion 21b3 are sequentially formed on the inner periphery of the end portion on the open portion 21b side toward the gear holding portion 21c side. However, the elastic member step 21b3 does not appear in the IV-IV cross section (FIG. 4) of FIG. 1, but is the step that appears in the VV cross section (FIG. 5).

The gear holding portion 21c is provided with a worm 13 of the motor 10 and a gear storage chamber (deceleration mechanism storage chamber) 21c1 for storing the worm wheel 14 meshing with the worm 13. The gear storage chamber 21c1 has a worm storage chamber 21c2 for storing the worm 13 and a worm wheel storage chamber 21c3 for storing the worm wheel 14, and the worm wheel storage chamber 21c3 has one end (FIG. 1, FIG. The upper part of 2 is open, and the other end part (lower part of the same) is connected to a connecting cylinder part 21c4 for connecting to another bracket. Further, a shaft support wall 21c5 and a shaft end pressing chamber 21c6 are formed in the gear storage chamber 21c1 on the side opposite to the tubular portion 21a. The shaft support wall 21c5 has a tip end portion of the rotary shaft 10b of the motor 10. A bearing hole 21c7 for rotatably receiving is formed. The bearing hole 21c7 defines the radial position of the motor 10 (rotating shaft 10b).

The shaft end pressing member 24 is inserted into the shaft end pressing chamber 21c6. The shaft end pressing member 24 includes a U-shaped bearing plate 24a that contacts the tip of the rotating shaft 10b, and a rubber member 24b that presses the bearing plate 24a toward the rotating shaft 10b. The bearing plate 24a has a three-layer structure in which a resin plate 24a1 and a metal plate 24a3 are bonded together by a sintered sheet 24a2 (FIG. 7). Since the resin plate 24a1 contacts the tip of the metal rotating shaft 10b, the bearing plate 24a does not generate a metallic sound, and the metal plate 24a3 contacts the rubber member 24b, so that strength is obtained. The shaft end pressing member 24 prevents the rotating shaft 10b from moving in the protruding direction when the worm 13 rotates. For example, in FIG. 4, even if the worm 13 tries to rotate the worm wheel 14 in either the left or right direction and receives the force of the rotating shaft 10b moving leftward (forward), the rotating shaft 10b is The tip portion 10b1 (its tip surface) abuts the shaft end pressing member 24, and the leftward movement is blocked.

A supported shaft 14a and a worm wheel 14 are integrally formed on the feed screw shaft 11 by insert molding. The gear portion cover 23 closes the worm wheel storage chamber 21c3 of the gear holding portion 21c, and at the same time closes the loose fitting hole 23a for rotatably holding the supported shaft 14a (worm wheel 14) and the shaft end pressing chamber 21c6. It has a lid portion 23d. The feed screw shaft 11 is inserted into the connecting cylinder portion 21c4, and the annular bush 25 loosely fitted to the outer circumference of the feed screw shaft 11 is press-fitted into the bottom portion of the worm wheel storage chamber 21c3. The gear portion cover 23 is screwed to the gear holding portion 21c and closes the worm wheel storage chamber 21c3.

A storage step portion 21a1 for storing the thrust elastic member 30 is formed in a communication portion between the tubular portion 21a of the tubular main body 21 and the gear holding portion 21c. The thrust elastic member 30 is an annular member made of an elastic material, the axis of which is parallel to the inner cylindrical surface 30a and the outer cylindrical surface 30b, and is orthogonal to the front and rear end surfaces of the annular front surface 30c and the annular rear surface 30d ( (Figure 6). The thrust elastic member 30 is fitted to the outer peripheral surface of the bearing boss 10c in a state where the diameter is expanded from the free state, and the inner cylindrical surface 30a is brought into contact with the outer peripheral surface of the bearing boss 10c by the elastic diameter reducing force. On the other hand, the outer cylindrical surface 30b parallel to the inner cylindrical surface 30a is not in contact with the inner cylindrical surface 21a2 of the storage step portion 21a1 when the motor 10 is correctly housed in the case 20. Further, the annular front surface 30c and the annular rear surface 30d elastically contact the storage step portion 21a1 and the axial front end surface (one end portion) 10a1 of the motor body 10a.

The composite elastic member 40 includes an annular thrust elastic portion (thrust elastic member) 40a fitted to the outer circumference of the bearing boss 10d of the motor 10 and a non-circular shape corresponding to the motor main body 10a fitted to the outer circumference of the rear end portion of the motor main body 10a. It has a radial elastic portion (radial elastic member) 40b (a rectangular tubular shape with four corners having a semi-cylindrical shape), and a connecting portion 40c that connects between the thrust elastic portion 40a and the rear end portion of the radial elastic portion 40b. .. A deformation space 40d is formed between the thrust elastic portion 40a and the radial elastic portion 40b. Since the thrust elastic portion 40a and the radial elastic portion 40b have the deformation space 40d therebetween, they can be deformed along the shape of the mounted portion, and manufacturing errors and the like can be absorbed. The axial thickness of the connecting portion 40c is sufficiently smaller than the axial thicknesses of the thrust elastic portion 40a and the radial elastic portion 40b, and the connecting portion 40c has a thickness capable of connecting the thrust elastic portion 40a and the radial elastic portion 40b. Any shape is acceptable. Further, the composite elastic member 40 is formed with an outer peripheral compression rib 40e which is flush with the connecting portion 40c and protrudes toward the outer peripheral side of the radial elastic portion 40b. The outer peripheral compression rib 40e does not have to be flush with the connecting portion 40c.

The thrust elastic portion 40a is fitted to the outer peripheral surface of the bearing boss 10d in a state where the diameter is expanded from the free state, and the inner cylindrical surface 40a1 parallel to the axis is brought into contact with the outer peripheral surface of the bearing boss 10d of the motor 10 due to the elastic contracting force. To do. On the other hand, the outer cylindrical surface 40a2, which is parallel to the inner cylindrical surface 40a1, has the deformation space 40d, and thus is not constrained by other members.

The radial elastic portion 40b is inserted in a cylindrical space between a rear end outer peripheral surface of the motor body 10a of the motor 10 and an inner peripheral surface of the tubular portion 21a of the tubular body 21 in a compressed state. At that time, in the radial elastic portion 40b, the inner cylindrical surface 40b1 parallel to the axis of the radial elastic portion 40b contacts the outer peripheral surface of the rear end of the motor body 10a of the motor 10, and the outer cylindrical surface 40b2 also parallel to the axis of the radial main body 40b. The inner peripheral surface of the tubular portion 21 a of the contact 21 is in contact with the inner peripheral surface of the tubular portion 21 a. That is, the radial elastic portion 40b serves to determine the position in the radial direction within the tubular portion 21a of the motor 10 (motor body 10a).

The lid body 22 includes a non-circular fitting rib 22 a (a square tubular shape having four semi-cylindrical corners) corresponding to the motor body 10 a, which is fitted to the lid step portion 21 b 2 of the opening portion 21 b, and the composite elastic member 40. It has a pressing rib 22b that presses the thrust elastic portion 40a from the axial direction, three screw seats 22c corresponding to the three screw seats 21b1 of the tubular body 21, and a plug insertion portion 22d. The plug insertion portion 22d faces the relay terminal 26 connected to the power supply terminal 10e of the motor 10, and the pressing rib 22b is divided by the passage route 22f (FIG. 2) of the relay terminal 26. ..

In the lid 22, the motor 10 having the composite elastic member 40 mounted at the rear end is fitted into the tubular portion 21a from the open portion 21b, and the fitting rib 22a is fitted into the lid step portion 21b2. By aligning the screw seats 22c with the three screw seats 21b1 and tightening the fixing screw 22g, the screw seats 22c are tightened and fixed to the tubular main body 21. In this fixed state, the thrust elastic member 30 is compressed in the thrust direction between the tubular portion 21a and the axial front end surface (one end portion) 10a1 of the motor body 10a, and the thrust elastic portion 40a is pressed by the pressing rib 22b. Is compressed in the thrust direction between the rear end surface (the other end) 10a2 of the motor body 10a in the thrust direction. Further, the radial elastic portion 40b is compressed in the radial direction between the outer peripheral surface of the motor body 10a and the inner peripheral surface of the tubular body 21. The elastic member step portion 21b3 is in a non-contact state with the radial elastic portion 40b, and no force in the thrust direction is generated. The outer peripheral compression rib 40e is closely compressed between the lid step portion 21b2 and the front end surface of the fitting rib 22a of the lid 22.

That is, in the above motor unit 100, the front and rear ends of the motor body 10a are elastically pressed and supported in the thrust direction by the thrust elastic members 30 and the thrust elastic portions 40a of the composite elastic members 40, and the rear end portion of the motor body 10a is not supported. Since it is elastically pressed and supported in the radial direction by the radial elastic portion 40b, the vibration of the motor 10 is difficult to be transmitted to the case 20, and the generation of vibration and abnormal noise is suppressed. Further, since the cylindrical main body 21 and the lid 22 are joined with the outer peripheral compression rib 40e sandwiched therebetween, the inside of the case 20 is completely sealed, and the sound and vibration generated by the motor 10 in the case 20 are exposed to the outside. Hard to leak.

In the motor unit 100 described above, the motor body 10a and the motor rotating shaft 10b are supported in the radial direction with respect to the case 20, the rear end portion of the motor body 10a is supported by the cylindrical body 21 via the radial bearing portion 40b, and Since the motor rotation shaft 10b protruding forward of the main body 10a is supported by the bearing hole 21c7, the axial interval between the front and rear radial direction support positions becomes longer than the axial length of the motor main body 10a, and the front and rear radial direction support positions are increased. Even if is displaced in the radial direction, the inclinations of the motor main body 10a and the motor rotation shaft 10b are small, the positioning is performed with high accuracy, and it is difficult for the shaft to shift.

Since the thrust direction elastic member 30 is fitted to the bearing boss 10c formed on the front end surface 10a1 of the motor body 10a, the vibration of the rotating shaft 10b can be absorbed at a position close to the rotating shaft 10b, and the thrust of the motor body 10a can be reduced. It is possible to suppress the generation of vibration and abnormal noise.

In the motor unit 100, since there is a radial gap between the thrust direction elastic member 30 mounted on the front end surface 10a1 of the motor body 10a and the inner cylindrical surface 21a2, the tip end portion 10b1 of the rotating shaft 10b is fixed to the bearing hole 21c7. The insertion of the elastic member 30 in the thrust direction is not obstructed during the assembling work for inserting the tip end portion 10b1 into the end portion 10b1 smoothly, and the assembling property is excellent.

Since there is a gap between the thrust direction elastic member 30 and the thrust elastic portion 40a between the radial direction case 20 and the radial direction case 20, only the thrust direction position of the motor body 10a is restricted, and the radial direction position is not restricted. The radial elastic member 40b can reliably regulate the position in the radial direction.

In the illustrated embodiment, the thrust elastic member 30 and the thrust elastic portion 40a are entirely overlapped with each other when viewed in the axial direction. Since the thrust elastic member 30 and the thrust elastic portion 40a at least partially overlap each other in the axial direction, the force acting between the thrust elastic member 30 and the thrust elastic portion 40a is directly transmitted to the facing position parallel to the axial direction. Further, the motor body 10a and the case 20 are unlikely to be twisted, and the tilting, the shake and the like acting on the rotating shaft 10b can be effectively prevented.

The thrust elastic member 30 and the thrust elastic portion 40a are preferably circular with the rotation shaft 10b as the center, but may be rectangular or may be a plurality of protrusions.

The axial length a of the thrust elastic member 30 and the axial length b of the thrust elastic portion 40a of the composite elastic member 40 may be the same, or one of them may be short. By making the axial length a of the thrust elastic member 30 different from the axial length b of the thrust elastic portion 40a of the composite elastic member 40, it is possible to damp vibrations of different cycles generated in the motor 10 or the like.

The thrust elastic member 30 and the composite elastic member 40 may be formed of the same material or different materials, and may have different cross-sectional areas in the radial direction. By using different materials and different cross-sectional areas, it is possible to adjust the amount of compression, the amount of damping of vibration, etc., the damping frequency, and the like.

In the motor unit 100, since the thrust elastic portion 40a and the radial elastic portion 40b are integrally provided on the composite elastic member 40, the number of parts is reduced and the assembling property is excellent. The thrust elastic portion 40a and the radial elastic portion 40b may be provided as separate members.

In the above-described embodiment, the entire motor body 10a of the motor 10 fits inside the tubular portion 21a of the tubular body 21. The pressing rib 22b of the lid 22 has a short shape that fits into the end of the tubular portion 21a. However, the length of the tubular portion 21a is set such that a part of the rear portion of the motor body 10a projects from the tubular portion 21a, and the length of the pressing rib 22b is set to a tubular shape that covers a portion of the rear portion of the motor body 10a. Good.

In the above embodiment, the thrust elastic member 30 is compressed in the thrust direction between the tubular portion 21a and the front end surface 10a1 of the motor body 10a in the axial direction, and the thrust elastic portion 40a includes the pressing rib 22b and the motor body 10a. It is compressed in the thrust direction with the rear end surface 10a2 in the thrust direction. However, the thrust elastic member 30 and the thrust elastic portion 40a are disposed between the tubular portion 21a and the front end face 10a1 (direction parallel to the output shaft) and between the pressing rib 22b and the rear end face 10a2 in the thrust direction (parallel to the output shaft). It does not need to be compressed as long as it is present (in no direction) (without a gap).

In the above embodiment, the radial elastic portion 40b is inserted in a cylindrical space between the outer peripheral surface of the rear end portion of the motor body 10a of the motor 10 and the inner peripheral surface of the tubular portion 21a of the tubular body 21 in a compressed state. Has been done. However, the radial elastic portion 40b is provided in the tubular space (in the radial direction of the output shaft) between the outer peripheral surface of the rear end portion of the motor body 10a and the inner peripheral surface of the tubular portion 21a of the tubular body 21 (without a gap). It may not be compressed as long as it is interposed.

In the above embodiment, the gear mechanism driven by the rotating shaft 10b of the motor 10 is a reduction mechanism having the worm 13 fixed to the rotating shaft 10b and the worm wheel 14 meshing with the worm 13. However, the present invention reduces the speed. It is applicable not only to the mechanism. For example, a gear mechanism that does not decelerate may be used, or a movement direction conversion mechanism such as a bevel gear mechanism may be used.

10 motor 10a motor body 10a1 front end face (one end)
10a2 rear end face (other end)
10b Rotating shaft (output shaft)
10b1 Tip part 10c 10d Bearing boss 10e Feeding terminal 11 Feed screw shaft 13 Worm 14 Worm wheel 14a Supported shaft 20 Case 21 Cylindrical body 21a Cylindrical part 21a1 Storage step 21a2 Inner cylindrical surface 21b Opening 21b1 Screw seat 21b2 Lid Step portion 21b3 Elastic member step portion 21c Gear holding portion 21c1 Gear storage chamber 21c2 Worm storage chamber 21c3 Worm wheel storage chamber 21c4 Connecting cylinder portion 21c5 Shaft support wall 21c6 Shaft end pressing chamber 21c7 Bearing hole (radial bearing portion)
22 lid 22a fitting rib 22b pressing rib 22c screw seat 22d plug insertion portion 22f passage 22g fixing screw 23 gear portion lid 23a loose fitting hole 23d lid 24 shaft end pressing member (thrust bearing portion)
24a Bearing plate 24a1 Resin plate 24a2 Sintered sheet 24a3 Metal plate 24b Rubber member 25 Annular bush 30 Thrust elastic member 30a Inner tubular surface 30b Outer tubular surface 40 Composite elastic member 40a Thrust elastic part (thrust elastic member)
40a1 inner cylindrical surface 40a2 outer cylindrical surface 40b radial elastic portion (radial elastic member)
40b1 inner cylindrical surface 40b2 outer cylindrical surface 40c connecting portion 40d deformation space 40e outer peripheral compression rib

Claims (6)

In a motor unit having a motor with an output shaft protruding from an end of a motor body, and a case accommodating and supporting the motor,
Between the motor body and the case, it possesses a thrust elastic member interposed output shaft in a direction parallel, the radial elastic member interposed in a radial direction of the output shaft,
The thrust elastic member and the radial elastic member are provided with a composite elastic member integrally molded,
The integrally formed composite elastic member includes a radial elastic member fitted to the outer periphery of the motor body, a thrust elastic member fitted to a bearing boss formed to project at an axial end of the motor body, and A motor unit comprising: a radial elastic member and a thrust elastic member; and a connecting portion having a thickness smaller than an axial length of the radial elastic member and the thrust elastic member . The motor unit according to claim 1, wherein a pair of the thrust elastic members are provided on one end side and the other end side of the motor body so as to be axially separated from each other. The motor unit according to claim 2, wherein the pair of thrust elastic members have a radial gap between the thrust elastic members and the case. The motor unit according to claim 2, wherein the pair of thrust elastic members at least partially overlap each other when viewed from the output shaft direction. The motor unit according to any one of claims 2 to 4 , wherein axial lengths of the pair of thrust elastic members are different from each other. The motor unit according to any one of claims 1 to 5 , wherein the motor and the case have a non-circular shape in a cross section orthogonal to the axis.

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