JPH0753406Y2 - Motor shaft support - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor shaft supporting device, and more particularly to a motor shaft supporting device for supporting a rotating shaft of a motor which receives a force in a thrust direction.

[0002]

2. Description of the Related Art Conventionally, as a shaft supporting device for a motor of this type, there is, for example, one shown in Japanese Utility Model Laid-Open No. 60-103743.

FIG. 5 is a sectional view showing the structure of the main part of the shaft support device for such a motor. As shown in the figure, a rotary shaft 12 is supported in the housing 10 of the motor.
Further, a concave portion is formed at the tip of the rotary shaft 12, and the hard ball 26 is meshed with the concave portion. A worm gear is formed on the side surface of the rotary shaft 12 (not shown), and a worm wheel is provided in mesh with the worm gear (not shown). According to this structure, when the rotary shaft 12 is normally or reversely rotated, the worm wheel can be normally or reversely rotated accordingly.

In such a motor shaft support device, when the rotary shaft 12 rotates by driving the motor,
The rotary shaft 12 is given the thrust direction of the load weight. The load weight is caused by the engagement between the worm wheel and the worm gear.

Therefore, in the motor shaft supporting apparatus shown in FIG. 5, a load in the thrust direction of the rotary shaft 12 is brought into contact with the end of the rotary shaft 12 at a position facing the end of the rotary shaft 12 of the housing 10. A thrust bearing portion 14 is formed for receiving and supporting the shaft.

The thrust bearing portion 14 is provided in the housing 1
It is composed of a metal plate 18 disposed in the recess 16 formed in 0, and a synthetic resin portion 20 formed by injection molding between the metal plate 18 and the housing 10 side end. According to this structure, the load in the thrust direction of the hard sphere 26 that is in contact with the metal plate 18 can be received, and rattling in the thrust direction can be prevented.

[0007]

FIG. 6 is a sectional view taken along line VV 'of the motor shaft support device shown in FIG. As shown in the figure, in the conventional shaft supporting device for a motor, an injection inlet 22 for injecting a synthetic resin material into the housing 10 is provided in the housing 10 in the axial direction of the rotary shaft 12. It was formed in the direction intersecting with. Therefore, it is necessary to increase the size of the injection inlet 22 by a size corresponding to the nozzle diameter of the injection molding machine. Therefore, the distance d from the metal plate 18 to the side end of the recess 16 is equal to the nozzle diameter. There was a problem that the size of ₁ became large and it became difficult to downsize the motor.

Further, due to the manufacturing error of the rotary shaft 12,
The length of the rotary shaft in the longitudinal direction may be too long or too short, but if it is too long, the load on the metal plate 18 is too large, which causes malfunction of the motor.
If it is too short, there is a problem that it causes rattling of the rotary shaft 12.

Further, the injection inlet 22 has a synthetic resin portion 2
After forming 0, it is open to the outside as it is, and since the sealing means of the special synthetic resin portion 20 is not adopted, the load in the thrust direction is applied to the rotary shaft 12 and the synthetic resin portion is applied. Synthetic resin part 20 when 20 is compressed
However, there was a problem that it could be leaked outside.

The present invention has been made in view of such conventional problems, and an object thereof is to shorten a distance from a metal plate to an end portion of a housing while forming a synthetic resin portion by injection molding. This contributes to downsizing of the motor by shortening the overall length of the motor, prevents malfunction or rattling of the motor due to dimensional error in the longitudinal direction of the rotating shaft, and further applies load in the thrust direction to the rotating shaft. It is an object of the present invention to provide a shaft support device for a motor in which the synthetic resin portion does not protrude outside the injection inlet when the synthetic resin portion is compressed.

[0011]

A motor shaft supporting device of the present invention is rotatably and rotatably supported in a motor housing through a radial bearing portion, and partially has a rotational force transmitting portion in a crossing direction. In a motor including a rotary shaft and a thrust bearing portion that abuts a tip of the rotary shaft and receives a thrust load of the rotary shaft, the radial bearing portion includes a fitting portion for the thrust bearing portion, The thrust bearing portion has a fitted portion that fits in the fitting portion of the radial bearing portion so that the position thereof can be adjusted in the thrust direction, and the thrust bearing portion is brought into contact with the tip end of the rotary shaft to adjust the thrust mounting position. A plug thrust, an injection inlet formed in the motor housing on the tip side of the rotary shaft and penetrating in the axial direction of the rotary shaft, the plug thrust from the injection inlet, and the motor. Characterized in that it comprises a synthetic resin part which is injection molded between the Ujingu.

Further, the invention of claim 2 is characterized in that the inner wall surface of the injection inlet is formed in a taper shape toward the outer side in the axial direction of the rotating shaft.

Further, the invention of claim 3 is characterized in that the thrust bearing portion includes a rigid plate sandwiched between the plug thrust and the synthetic resin portion.

[0014]

In the shaft supporting device for the motor having the above-mentioned structure, the synthetic resin material is formed by injecting the synthetic resin material into the housing through the injection injection port penetrating in the axial direction of the rotary shaft. It is possible to form the synthetic resin part regardless of the size of the nozzle diameter. Therefore, it is possible to reduce the axial thickness of the synthetic resin part, shorten the overall length of the motor, and reduce the size. Become.

In addition, since the mounting position of the plug thrust can be freely adjusted, by adjusting the position of the plug thrust, manufacturing and assembling errors in the length direction of the rotary shaft can be absorbed. You can

According to the second aspect of the present invention, the inner wall surface of the injection inlet is tapered toward the outer side in the axial direction of the rotary shaft. As a result, even if the synthetic resin portion is compressed by the load in the thrust direction on the rotary shaft and tries to protrude from the injection inlet, the synthetic resin portion is compressed by the inner wall surface of the injection inlet due to the wedge effect and is pushed back to the outside. It is prevented from protruding.

Further, according to the invention of claim 3, a rigid plate is sandwiched between the plug thrust and the synthetic resin portion. As a result, the plug thrust is generated by the thrust force of the rotating shaft.
It is possible to prevent deformation due to a concentrated load.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a sectional view showing a preferred embodiment when the present invention is applied to a motor for seat reclining in a power seat device.

In this embodiment, the rotor 32, the magnet 34, the rotary shaft 36,
A worm wheel 38, a thrust bearing portion 40, etc. are arranged.

The motor housing 30 is formed by combining a metal housing portion 42 and a resin housing portion 44.

The metal housing portion 42 is formed of an iron plate,
The resin housing portion 44 is made of a synthetic resin material such as PET.

The rotor 32 is rotatably arranged in the metal housing portion 42.

The magnet 34 is attached to the inner wall surface of the metal housing portion 42 around the rotor 32 to form a field.

A commutator 46 is provided at the end of the rotor 32, and a brush 48 that comes into contact with the commutator 46 is provided around the metal housing 42 side of the commutator 46.

The rotary shaft 36 penetrates the rotor 32 and the commutator 46, and is arranged so as to straddle the metal housing portion 42 and the resin housing portion 44. That is, the rotary shaft 36 is rotatably supported by the radial bearing 50 in the metal housing portion 42 and the resin housing portion 44, and the movement in the radial direction is restricted.

Further, a worm gear 52 is formed in a part of the rotary shaft 36 on the resin housing portion 44 side, and the worm wheel 38 meshes with the worm gear 52 in a direction orthogonal to the axial direction of the rotary shaft 36. It is designed to transmit torque. Therefore, when the rotating shaft 36 rotates forward and backward, a load in the thrust direction is applied to the rotating shaft 36 via the worm gear that meshes with the worm wheel 38.

Therefore, in this embodiment, the resin member 54 provided at the end portion of the rotary shaft 36 on the side of the metal housing portion 42 is pressed against and supported by the metal housing portion 42 ', and the end portion on the side of the resin housing portion 44 is supported. The thrust bearing portion 40 provided on the side end portion of the resin housing portion 44 is pressed and supported to receive the load in the thrust direction.

FIG. 2 is an enlarged view of a portion surrounded by A in FIG.

In the present embodiment, in order to reduce the frictional resistance generated at the tip of the rotary shaft 36, the tip of the rotary shaft 36 is formed into a spherical shape.

Then, on the outer end surface of the radial bearing 36 which pivotally supports the rotary shaft 36, as shown in FIG. 3A, a pair of fitting concave portions 5 functioning as fitting portions for the thrust bearing portion.
1, 51 are formed. In this embodiment, the fitting recesses 51, 51 are formed in a slit shape having a predetermined depth.

Further, the thrust bearing portion 40 of this embodiment is
Metal plate 56, synthetic resin portion 60 and resin plug thrust 6
Including 8.

The resin plug thrust 68 is shown in FIG.
As shown in (B), it has a cylindrical thrust body 68a, and a pair of projections 70, 70 protruding from the outer peripheral surface of the thrust body 68a in the radial direction.

The resin plug thrust 68 is
As shown in FIG. 3 (C), the pair of projections 70, 70 are assembled to the radial bearing 50 so as to be fitted in the fitting recesses 51, 51 so as to be movable in the thrust direction, and the resin plug thrust 68 is The contact with the tip of the rotary shaft 36 functions as a thrust receiver.

Therefore, this resin plug thrust 68
When the rotary shaft 36 is assembled to the radial bearing 50, the rotary shaft 36 can come into contact with the tip of the rotary shaft 36 and move its position in the thrust direction with respect to the radial bearing 50. The dimensional error in the direction and the assembly error can be absorbed.

Further, the pair of protrusions 70, 70 engage with the fitting recesses 51, 51, whereby the radial bearing 5
It also functions as a detent for the resin plug thrust 68 with respect to zero.

Further, by sandwiching the metal plate 56 between the resin plug thrust 68 and the synthetic resin portion 60, it is possible to prevent the resin plug thrust 68 from being deformed by a concentrated load due to the thrust force of the rotating shaft 36. I have to.

The synthetic resin portion 60 is elastic so that the rotary shaft 36 is
The thrust rattle is prevented by absorbing the load in the thrust direction, and is formed between the metal plate 56 and the side end portion of the resin housing portion 44 by injection molding. In this way, by preventing thrust rattle,
It is possible to prevent the reverse sound of the rotating shaft 36 from being generated. The synthetic resin portion 60 is formed by injecting a synthetic resin material into the resin housing portion 44 through an injection injection port 64 for injection molding the synthetic resin portion formed in the resin housing portion 44.

The injection inlet 64 is formed at the side end of the resin housing portion 44 so as to penetrate in the axial direction of the rotary shaft 36, and is injection molded into the injection inlet 64. Synthetic resin part 6 regardless of the nozzle diameter of the machine
A thickness of 0 can be set.

Therefore, the distance d ₂ between the metal plate 56 and the inner wall surface of the side end portion of the resin housing portion 44 can be set short, and the total length of the motor can be shortened to contribute to downsizing of the motor. Will be things. For example, the distance d ₂ between the metal plate 56 and the inner wall surface of the side end portion of the resin housing portion 44 is 8. because of the diameter of the nozzle of the conventional injection molding machine.
What has been about 5 mm can be set to about 1 mm, which can sufficiently contribute to downsizing of the motor.

The injection injection port 64 is formed in a taper shape with its inner wall surface 66 directed outward in the axial direction of the rotary shaft 36. As a result, even if a load in the thrust direction is applied to the synthetic resin portion 60 when the rotating shaft 36 of the motor is rotated in the forward and reverse directions, and the compressive force acts on the synthetic resin portion 60, the inner wall surface 66 of the injection injection port 64 is tapered, so that the synthetic resin Even if the portion 60 tries to protrude from the injection inlet 64, it is pushed back by the inclination of the inner wall surface 66 and does not protrude outside the injection inlet 64.

The synthetic resin portion 60 is formed by injection molding a synthetic resin material such as Duracon, PBT, nylon or the like, according to the heat resistant temperature.

Next, the order of assembling the motor of this embodiment will be described.

First, the metal plate 56 is inserted into the resin housing 44 as shown in FIG.

Next, the resin plug thrust 68 and the radial bearing 50 are assembled as shown in FIG. 3C, and in this state, the resin plug thrust 68 and the radial bearing 5 are assembled.
0 is assembled in a predetermined position in the resin housing 44 as shown in FIG. At this time, the radial bearing 50 is fixed at a predetermined position inside the resin housing 44.

Next, the rotary shaft 36 is inserted into the radial bearing 50.
Insert the tip of the. At this time, the rotary shaft 36 is arranged in contact with the resin plug thrust 68, but the resin plug thrust 68 has its projection 70 on the radial bearing 50.
Since it is supported only by engaging with the fitting concave portion 51 formed in the above, the resin plug thrust 68 is moved so as to be pushed out in the thrust direction by the tip end portion of the inserted rotary shaft 36, and the resin plug thrust 68 is further pushed. Thrust 6
The movement of 8 also moves the metal plate 56 in the same direction. In this way, the resin plug thrust 68 and the metal plate 56 are
The position of is determined according to the length of the rotary shaft 36, which makes it possible to absorb manufacturing errors and assembly errors in the direction of the length of the rotary shaft 36.

Then, a synthetic resin material is made to flow into the resin housing portion 44 from an injection inlet 64 formed at the side end portion of the resin housing portion 44 by an injection molding machine, and subsequently, the synthetic resin material is made in the resin housing portion 44. The material is cooled and solidified to obtain the synthetic resin portion 60. Accordingly, the resin plug thrust 68 and the metal plate 56 can be fixed in a state where the resin plug thrust 68 and the tip end portion of the rotary shaft 36 are in contact with each other with an appropriate pressure.

As described above, in the motor shaft support device of this embodiment, the injection inlet 64 penetrates in the axial direction of the rotary shaft 36, so that injection injection is performed from the direction intersecting the axial direction as in the conventional case. The thickness of the synthetic resin portion 60 can be arbitrarily set without being influenced by the diameter of the nozzle of the injection molding machine as compared with the case of performing the above. As a result, the distance d ₂ between the metal plate 56 and the inner wall surface of the side end portion of the resin housing portion 44 can be shortened to shorten the total length of the motor, and thus the motor can be downsized. Become.

Further, since the inner wall surface 66 of the injection inlet 64 is formed so as to taper outward in the axial direction of the rotary shaft 36,
Even if a load in the thrust direction is applied to the rotary shaft 36 and a compressive force acts on the synthetic resin portion 60, the synthetic resin portion 60 does not protrude from the injection inlet 64 to the outside.

Further, since the positions of the resin plug thrust 68 and the metal plate 56 are determined according to the length of the rotary shaft 36, the manufacturing error of the length of the rotary shaft 36 can be absorbed. Therefore, there is no inconvenience that the rotating shaft 36 is too long to cause a malfunction of the motor, and the rotating shaft 36 is too short to cause rattling of the rotating shaft 12. That is, as shown in FIG. 2, when the resin plug thrust 68 projects from the radial bearing 50 by d ₃ at the reference position, when the rotary shaft 36 is longer than the design value, the value is smaller than the design value. When the rotary shaft 36 is inserted into the radial bearing 50 for a long time, the resin plug thrust 6
8 and the metal plate 56 are pushed out by a large distance,
Therefore, the positions of the resin plug thrust 68 and the metal plate 56 are closer to the injection inlet 64 than the reference position. Therefore, the synthetic resin portion 60 formed after the rotation shaft 36 is inserted
The width of is reduced by the length of the rotary shaft 36 which is longer than the design value, so that the manufacturing error of the length of the rotary shaft 36 is absorbed. On the other hand, when the rotating shaft 36 is shorter than the design value, the distance by which the resin plug thrust 68 and the metal plate 56 are pushed out when the rotating shaft 36 is inserted into the radial bearing 50 becomes smaller by that amount. Resin part 60
Since the width of the rotating shaft 36 is wide, a manufacturing error in the length of the rotating shaft 36 can be absorbed.

FIG. 4 shows still another embodiment.

In this embodiment, in addition to the state of FIG. 1, the case where the thrust force received by the rotary shaft 36 is large is assumed.

That is, when the thrust force increases, the surface pressure between the resin plug thrust 68 and the metal plate 56 increases, and as a result, the temperature rise due to the sliding friction between the rotary shaft 36 and the resin plug thrust 68 increases. Therefore, if the synthetic resin portion 60 is made of a resin having low heat resistance, such as Duracon, the synthetic resin portion 60 may be deformed by thrust force and heat, and conversely, the synthetic resin portion 60 is made of synthetic resin having high heat resistance, such as PBT, NY66. , PET or the like causes problems in terms of formability and cost.

Therefore, in this embodiment, the metal plate 56,
By providing a resin plate 72 made of a synthetic resin having high heat resistance, for example, PBT, NY66, PET or the like, between the synthetic resin portion 60 and the synthetic resin portion 60, heat is insulated by the resin plate 72, and the synthetic resin portion 60 is heated. Is prevented from being transmitted, and the synthetic resin portion 60 can sufficiently cope with a synthetic resin having low heat resistance.

The other structure and operation are the same as those of the above-mentioned embodiment, and the explanation is omitted.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the present invention.

For example, in the above-mentioned embodiment, the case where the motor shaft supporting device according to the present invention is applied to the motor for seat reclining in the power seat device has been described as an example, but the present invention is not limited to this. The present invention can be applied to other applications such as a motor for a seat slide, a motor for a seat lifter, and a motor for a power window.

[0058]

As described above in detail, according to the motor shaft supporting apparatus of the present invention, the synthetic resin material is injected and injected into the housing through the injection injection port penetrating in the axial direction of the rotary shaft. Since the portion is formed, the total length of the motor can be shortened and the size can be reduced.

In addition, since the manufacturing error in the length of the rotary shaft can be absorbed by adjusting the position of the plug thrust, the motor malfunction or rattling does not occur.

Further, according to the invention of claim 2, even if a load in the thrust direction is applied to the rotary shaft, the synthetic resin portion is compressed and does not protrude from the injection inlet, so that the reliability of the shaft support device of the motor is improved. Can be improved.

Further, according to the third aspect of the present invention, it is possible to prevent the plug thrust from being deformed due to the concentrated load due to the thrust force of the rotary shaft, so that the reliability of the motor shaft support device is improved. Can be made.

[Brief description of drawings]

FIG. 1 is an overall sectional view of a motor according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of FIG.

3A is a perspective view for explaining the shape of the radial bearing, FIG. 3B is a perspective view for explaining the shape of the resin plug thrust, and FIG. 3C is a perspective view for explaining the shape of the resin plug thrust. It is a perspective view for explaining a state.

FIG. 4 is an enlarged view of a main part of another embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing a conventional motor shaft support device.

6 is a V-V 'of the conventional motor shaft support device shown in FIG.
It is sectional drawing in a cross section.

[Explanation of symbols]

 30 Housing 36 Rotating Shaft 40 Thrust Bearing Part 44 Resin Housing Part 56 Metal Plate 60 Synthetic Resin Part 64 Injection Injection Port 66 Inner Wall Surface

Claims (3)

[Scope of utility model registration request] 1. A rotary shaft, which is rotatably and rotatably supported in a motor housing via a radial bearing part, and has a rotational force transmitting part in a crossing direction in a part thereof, and an abutting end of the rotary shaft. In a motor including a thrust bearing portion that receives a thrust load of a rotating shaft, the radial bearing portion has a fitting portion for the thrust bearing portion, and the thrust bearing portion is the fitting portion of the radial bearing portion. A plug thrust that has a fitted part that is positionally adjustable in the thrust direction, and that abuts the tip of the rotary shaft when the rotary shaft is assembled and adjusts the thrust assembly position; An injection injection port formed on the front end side of the shaft and penetrating in the axial direction of the rotation shaft, and a synthetic resin portion injection-molded from the injection injection port between the plug thrust and the motor housing. A shaft support device for a motor, including: 2. The shaft supporting device for a motor according to claim 1, wherein an inner wall surface of the injection inlet is formed so as to taper outward in an axial direction of the rotary shaft. 3. The shaft support device for a motor according to claim 1, wherein the thrust bearing portion includes a rigid plate sandwiched between the plug thrust and the synthetic resin portion.