JP2000032703A - Motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor which realizes the circulation of leaking-out oil even if a motor is used in a horizontal posture and enables the extension of the life of a sleeve bearing. SOLUTION: A motor has a stationary member 32 with a cylindrical support member 38, a rotor 34 with a rotary shaft 46 and a sleeve bearing 48 provided between the cylindrical support member 38 and the rotary shaft 46. An annular protrusion 72 protruding outward in an axial direction is provided on one end surface of the sleeve bearing 48. A plate-shape member 74 is provided outside one end part of the sleeve bearing 48 and attached to the cylindrical support member 38 so as to be brought into contact with the annular protrusion 72, and an oil space 76 is formed between the plate-shape member 74 and the one end surface of the sleeve bearing 48.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a motor having a sleeve bearing.

[0002]

2. Description of the Related Art Conventional motors having a sleeve bearing are:
For example, the configuration shown in FIG. Referring to FIG. 6, this motor includes a stationary member 2 and a rotor 4 that is rotatable relative to stationary member 2. The stationary member 2 includes a mounting bracket 6 and a cylindrical support member 8,
One end of the cylindrical support member 8 is fixed to the mounting bracket 6. The rotor 4 includes a rotor body 10 and a rotating shaft 12 fixed to the rotor body 10. A rotor magnet 14 is mounted on the rotor body 10, and a stator 16 is attached to the cylindrical support member 8 so as to face the rotor magnet 14.

A sleeve bearing 18 for supporting a radial load and a slide bearing piece 20 for supporting a thrust load are provided between the rotary shaft 12 of the rotor 4 and the cylindrical support member 8 of the stationary member 2. Is provided. The sleeve bearing 18 is formed of a porous material, and contains a lubricating oil inside.

In such a motor, when the rotor 4 rotates in a predetermined direction, the oil in the sleeve bearing 18 oozes on the inner peripheral surface thereof due to the pumping action of the rotating rotary shaft 12. If the amount of oil bleeding increases, the oil scatters around due to centrifugal force, the oil contained in the sleeve bearing 18 decreases, and the life of the sleeve bearing 18 is significantly reduced.

Therefore, in the conventional motor, a plate-shaped member 22 is arranged outside one end of the sleeve bearing 18 in order to prevent the oil from scattering, and the plate-shaped member 22 is fixed to the rotating shaft 12. One end of the cylindrical support member 8 extends outward beyond the sleeve bearing 18, and the protruding end 24 covers the plate-like member 22 radially outward.

In the motor having such a configuration, the oil oozing out of the sleeve bearing 18 travels along the rotating shaft 12 to reach the plate-like member 22 and is radially outward from the rotating rotating shaft 12 and / or the plate-like member 22. Although scattered, the scattered oil flows down along the inner peripheral surface of the protruding end portion 24 of the cylindrical support member 8 and returns to the sleeve bearing 18. Therefore, it is possible to suppress the decrease due to the scattering of the oozed oil, and to keep the life of the sleeve bearing 18 long.

[0007]

When this motor is used in a vertical state (a state in which the rotating shaft 12 extends in the vertical direction),
As can be understood from FIG. 6, the oil that has oozed out of the sleeve bearing 18 circulates as described above, and a reduction in the oil can be suppressed. However, the motor is kept horizontal (rotary shaft 12
Plate-like member 2)
The oil scattered from 2 to the protruding end 24 of the cylindrical support member 18 does not flow toward the sleeve bearing 18 but flows out of the protruding end 24 to the outside, and the above-described circulation of the oil is not performed. Therefore, there is a problem that the oil is remarkably reduced and the life of the sleeve bearing 18 is shortened.

[0008] It is an object of the present invention to provide a motor which achieves the circulation of exuded oil even when the motor is used horizontally, thereby extending the life of the sleeve bearing.

[0009]

SUMMARY OF THE INVENTION The present invention provides a stationary member having a cylindrical support, a rotor having a rotating shaft, a sleeve bearing interposed between the cylindrical support and the rotating shaft. An annular projection is provided on one end surface of the sleeve bearing so as to protrude outward in the axial direction, and a plate-shaped member is provided outside one end of the sleeve bearing. An oil space is provided between the one end surface of the sleeve bearing and the cylindrical support so as to abut on the annular projection of the sleeve bearing.

According to the present invention, since the plate-shaped member is provided so as to contact the annular projection of the sleeve bearing, an oil space is formed between one end surface of the sleeve bearing and the plate-shaped member. Therefore, oil that has oozed out from the surface of the rotating shaft portion or between the rotating shaft portion and the sleeve bearing with the rotation of the rotating shaft portion is scattered into this oil space, and the scattered oil passes through this oil space from one end surface of the sleeve bearing. It penetrates into the interior and thus circulation of the oil is achieved. Therefore, scattering and outflow of oil to the outside can be suppressed, and the life of the sleeve bearing can be extended. In addition, since the plate-shaped member is in contact with the annular projection of the sleeve bearing, the radially outer peripheral surface of the oil space is closed, so that even when the motor is used in a horizontal state, the oozed oil scatters to the outside. , Can control outflow.

Further, the present invention is characterized in that an annular groove is formed on the one end face of the sleeve bearing at a position radially inside the annular projection.

According to the present invention, since the annular groove is formed on one end face of the sleeve bearing, the surface area of this one end face is increased, thereby making it possible to promote the penetration of oil into the sleeve bearing.

Further, the present invention provides the above-mentioned plate-like member,
It is characterized by being formed from a material having oil repellency.

According to the present invention, since the plate-shaped member is formed of an oil-repellent material, oil hardly adheres to the surface of the plate-shaped member, and the oil scattered in the oil space is supplied to one end surface of the sleeve bearing. Penetrates into it.

Further, according to the present invention, an annular recess is formed in the outer peripheral portion of the one end of the sleeve bearing, and an air escape groove extending from the annular concave portion to a predetermined portion is formed in an outer peripheral surface of the sleeve bearing. Further, a notch is formed in the plate-shaped member to allow air in the annular concave portion to escape.

According to the present invention, since the notch is formed in the plate-shaped member, when the rotary shaft portion of the rotor is inserted into the sleeve bearing, the air in the sleeve bearing passes through the air escape groove and the annular recess. It flows out of the notch to the outside, so that the rotating shaft can be easily mounted on the sleeve bearing.

Further, according to the present invention, an annular concave portion is formed on the outer peripheral portion of the one end of the sleeve bearing, and an air escape groove extending from the annular concave portion to a predetermined portion is formed on an outer peripheral surface of the sleeve bearing. Further, the annular projection of the sleeve bearing is formed with a communication groove for communicating the annular recess with the oil space.

According to the present invention, since the groove is formed in the annular projection of the sleeve bearing, when the rotary shaft portion of the rotor is inserted into the sleeve bearing, air in the sleeve bearing passes through the air escape groove and the communication groove. The fluid flows out between the plate upper member and the rotating shaft, and therefore, the rotating shaft can be easily mounted on the sleeve bearing.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a motor according to the present invention will be described below with reference to FIGS. FIG.
FIG. 2 is a sectional view showing a first embodiment of the motor according to the present invention, FIG. 2 is a partially enlarged sectional view showing a main part of the motor of FIG. 1, and FIG. It is a front view which expands and shows.

Referring to FIG. 1, the illustrated motor includes, for example, a stationary member 32 attached to a drive unit for driving a disk, and a rotor 34 rotatable relative to the stationary member 32. ing. The stationary member 32 has a substantially circular mounting bracket 36. A circular opening is formed in the center of the mounting bracket 36, and one end of a cylindrical support member 38 (constituting the cylindrical support portion) is fixed to the circular opening by, for example, press fitting. This cylindrical support member 38 may be formed integrally with the mounting bracket 36.

The rotor 34 has a cup-shaped rotor body 40. The rotor body 40 has a cylindrical peripheral side wall 42,
It has an end wall 44 provided at one end of the peripheral side wall 42,
A rotating shaft 46 (constituting a rotating shaft) is provided at the center of the end wall 44.
Are fixed, for example, by press fitting. One end of the rotating shaft 46 extends downward from the end wall 44 in FIG. 1, and the other end extends upward in FIG.

The rotary shaft 46 of the rotor 34 is rotatably supported by the cylindrical support member 38 via a sleeve bearing 48 and a slide bearing piece 50. The sleeve bearing 48 is called an oil-impregnated bearing, and is formed of a porous material such as a sintered alloy, and contains a lubricating oil inside. This sleeve bearing 4
Reference numeral 8 is mounted on the inner peripheral surface of the cylindrical support member 38 by, for example, press fitting. In addition, the sliding bearing piece 50 is provided with the cylindrical support member 3.
8 is attached to one end. In this embodiment, one end of the cylindrical support member 38 has a large inner diameter portion 52 having a somewhat larger inner diameter.
Further, an annular holding protrusion 54 is provided at a slight distance inward in the axial direction (vertical direction in FIG. 1) from the large inner diameter portion 52 and protrudes inward in the radial direction.
The large-diameter portion 52 of the cylindrical support member 38 has a closed support member 56.
Is provided, and by caulking one end surface of the cylindrical support member 38, the cylindrical support member 38 is fixed so as to contact the shoulder of the large-diameter portion 52. The slide bearing piece 50 is disposed inside the closing support member 56. The slide bearing piece 50 has a disk shape, the outer diameter of which is larger than the inner diameter of the annular holding projection 54, and the thickness thereof is set slightly smaller than the distance between the closing support member 56 and the annular holding projection 54. Have been. With such a configuration, the sliding bearing piece 50 is somewhat movable in the axial direction between the closing support member 56 and the annular holding projection 54, and thus the closing support member 56 can be moved. When fixing to the cylindrical support member 48 by caulking, a large force at the time of working is prevented from acting on the sliding bearing piece 50, whereby deformation and the like of the sliding bearing piece 50 can be prevented. The sleeve bearing 48 and its related configuration will be described later in further detail.

One end of the rotating shaft 46 of the rotor 34 is inserted into a sleeve bearing 48. The sleeve bearing 48 is the rotating shaft 4
6 supports an outer peripheral surface on one end side, and supports a radial load acting on the rotor 34. The sliding bearing piece 50 supports one end surface of the rotating shaft 46 that protrudes in an arc shape, and supports a thrust load acting on the rotor 34.

On the inner peripheral surface of the peripheral side wall 42 of the rotor main body 40, an annular rotor magnet 58 is mounted. A stator 60 is provided to face the rotor magnet 58. The stator 60 has a stator core 62 formed by stacking core plates, and the stator core 62 is attached to the outer peripheral surface of the cylindrical support member 38. A coil 64 is wound around the stator core 62 as required, and by supplying a drive current to the coil 64, the rotor 34 is rotationally driven in a predetermined direction by a magnetic action between the rotor magnet 58 and the stator 60.

Next, the sleeve bearing 48 and its related structure will be described with reference to FIGS. 2 and 3 together with FIG. Referring mainly to FIG. 2, in this embodiment, an annular projection 72 protruding outward in the axial direction is provided on one end surface (the upper end surface in FIGS. 1 and 2) of the sleeve bearing 48. The tip surface is formed substantially flat. Further, a plate-shaped member 74 is disposed outside one end of the sleeve bearing 48. The plate-like member 74 has a ring shape having a circular opening at the center, and the rotation shaft 46 extends through the circular opening. The outer peripheral portion of the plate-shaped member 74 is fixed to the inner peripheral surface of the cylindrical support member 38 by, for example, press-fitting so as to abut the distal end surface of the annular projection 72. Thus, the plate-like member 7
4, the space between the annular projection 72 and the plate-shaped member 74 is substantially closed, and the annular oil space 7 is provided between one end surface of the sleeve bearing 48 and the plate-shaped member 74.
6 are formed. The oil space 76 is opened on the inner peripheral surface side facing the rotating shaft 46, and the oil transmitted through the rotating shaft 46 scatters into the oil space 76, and the scattered oil flows from one end surface of the sleeve bearing 48 to the inside thereof. Penetrate.

In this embodiment, the plate-like member 74 is made of a material having oil repellency, for example, polytetrafluoroethylene (PTFE). It hardly adheres to the surface (inner surface) of the sleeve 74 and penetrates into the sleeve bearing 48 from one end surface thereof. Similar effects can be achieved by providing a coating layer of an oil-repellent material on the surface, particularly on the inner surface (the surface defining the oil space 76), instead of forming the plate-shaped member 74 from an oil-repellent material. Is done.

In this embodiment, the sleeve bearing 4
An annular groove 78 is formed on one end surface of the annular member 8, specifically at a position radially inside the annular projection 72. This annular groove 78 has a V-shaped cross section, and
The formation of 8 increases the surface area of the one end face, thereby promoting the penetration of oil from one end face of the sleeve bearing 48 into the inside. When the motor is used in a vertical state (the state shown in FIGS. 1 and 2), the annular groove 78 acts as an oil reservoir for the scattered oil, and the scattered oil permeates the interior more effectively. Done. Note that the cross-sectional shape of the annular groove 78 may be any other shape such as a rectangular shape, a semicircular shape, or the like. In addition, the annular groove 78
For example, a plurality may be provided concentrically.

In order to more effectively permeate oil from one end surface of the sleeve bearing 48, an annular projection 72 is provided on the outer peripheral portion of the one end surface, and the area defining the oil space 76 on the one end surface is reduced. It is desirable to make it larger. In addition, the annular groove 78 is formed radially inward of the annular projection 7 following the annular projection 78.
8 is preferably provided to increase the surface area of the annular groove 78.

An inclined surface 80 that is inclined inward in the axial direction toward the inside in the radial direction is formed on the inner peripheral portion at one end of the sleeve bearing 48. Therefore, when the motor is used in a vertical state, a part of the oil scattered in the oil space 76 is returned to the gap between the rotary shaft 46 and the sleeve bearing 48 along the inclined surface 80, and sufficient lubrication by the oil is performed. Done.

In this embodiment, the rotor 34 is configured as follows so as to be easily assembled. That is, an annular concave portion 82 is formed in the outer peripheral portion of one end of the sleeve bearing 48 by cutting out a corner portion. The outer peripheral surface of the sleeve bearing 48 extends from one end to a predetermined portion in the axial direction, in other words, the sleeve bearing 4.
An air escape groove 84 is formed in a region of the outer peripheral surface of the cylindrical support member 38 that contacts the inner peripheral surface of the cylindrical support member 38, and one end of the air escape groove 84 communicates with the annular concave portion 82. Further, a notch 86 is formed in a part of the outer peripheral portion of the plate-shaped member 74 corresponding to the annular concave portion 86.
With such a configuration, as understood from FIGS. 1 and 2, the rotating shaft 4 of the rotor 34 is attached to the sleeve bearing 48.
6 is inserted, the air in the sleeve bearing 48 is compressed by the insertion of the rotary shaft 46, and the compressed air is transmitted from the other end of the sleeve bearing 48 to the sleeve bearing 48 and the cylindrical support member 38. It flows into the annular recess 82 through the gap and the air escape groove 84, and further flows out through the notch 86 in the plate-shaped member 74. Since the air in the sleeve bearing 48 is vented in this manner, the rotating shaft 46 can be easily inserted into the sleeve bearing 48. It should be noted that the air escape groove 84 is formed in the circumferential direction of the sleeve bearing 48 by one.
One or two or more can be provided.

In this motor, when the rotor 34 rotates in a predetermined direction, the pumping action of the rotating rotary shaft 46 causes oil in the sleeve bearing 48 to seep into the inner peripheral surface thereof. The exuded oil is transmitted along the surface of the rotary shaft 46 to the outside in the axial direction of the sleeve bearing 48, and is scattered toward the oil space 76 by the action of the centrifugal force. Penetrate into
Therefore, the exuded oil is circulated through the oil space 76, and the decrease due to the scattering of the oil is significantly suppressed, so that the life of the sleeve bearing 48 can be extended.

When such a motor is placed in a horizontal state (rotating shaft 46).
1 is used in a horizontal state), the scattered oil accumulates in the lower portion of the oil space 76 and the accumulated oil permeates from one end surface of the sleeve bearing 48 as understood from FIG. Therefore, even when used in such a state, the circulation of the exuded oil is achieved, and a decrease due to oil scattering can be remarkably suppressed as in the case of using in a vertical state.

FIGS. 4 and 5 show a second embodiment of the motor according to the present invention. FIG. 4 is a cross-sectional view showing a second embodiment of the motor according to the present invention, and FIG.
FIG. 3 is a partially enlarged sectional view showing a part of the motor of FIG. This second
In the second embodiment, the sleeve-shaped bearing and the plate-shaped member are improved, and the members substantially the same as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

Referring to FIGS. 4 and 5, in the second embodiment, one end surface of sleeve bearing 48A (see FIGS. 4 and 5)
As in the first embodiment, an annular projection 72A protruding outward in the axial direction is provided on the upper end surface, and a plate-like member 74A is provided outside one end of the sleeve bearing 48A. . Further, a large-diameter portion 92 whose inner diameter is somewhat enlarged is provided at the other end (the upper end in FIGS. 4 and 5) of the cylindrical support member 38A. The plate-shaped member 74A is placed on a shoulder formed by the large-diameter portion 92, and is fixed to the other end of the cylindrical support member 38A by caulking the inner peripheral portion of the large-diameter portion 92. In this mounting state, the plate-like member 74A
Abuts against the distal end surface of the annular projection 72A, and
Is closed between the plate-shaped member 74A and the one end surface of the sleeve bearing 48A and the plate-shaped member 74A. Therefore, as in the first embodiment, the oil transmitted through the rotary shaft 46 scatters into the oil space 76, and the scattered oil permeates into the sleeve bearing 48 from one end face thereof. Further, by fixing the plate-shaped member 74A, the space between the cylindrical support member 38A and the plate-shaped member 74A is also closed, so that leakage of oil to the outside can be prevented more reliably.

In this embodiment, as in the first embodiment, an annular groove 78 and an inclined surface 80 are formed on one end surface of the sleeve bearing 48A. Further, the plate-like member 74
A, instead of providing a notch, the sleeve bearing 48A
A communication groove 94 extending in the radial direction is formed on the annular projection 72A. One or two or more communication grooves 94 can be provided at intervals in the circumferential direction. The communication groove 94 is shown in FIG.
As shown in the figure, the annular recess 82 provided at the outer peripheral portion at one end of the sleeve bearing 48A communicates with the oil space 76.

In the second embodiment, the sleeve bearing 48A is inserted by inserting the rotary shaft 46 in the second embodiment.
When the air inside is compressed, the compressed air flows from the other end of the sleeve bearing 48A to the annular recess 82 through the gap between the sleeve bearing 48A and the cylindrical support member 38A and the air escape groove 84, and further. Through the communication groove 94 and the oil space 76, it escapes from the space between the plate-shaped member 74A and the rotary shaft 46 to the outside, and the same effect as described above is achieved.

In the second embodiment, an oil repellent 96 is applied to the following locations in order to further prevent oil leakage. The inner peripheral surface of one end of the cylindrical support member 38A, that is, a portion where the closing support member 56 and the slide bearing piece 50 are mounted, and the other end of the cylindrical support member 38A, that is, a portion where the plate member 74A is mounted. An oil repellent 96 is applied to the inner surface of the inner peripheral portion of the end wall 44 of the rotor body 40.
Other configurations of the second embodiment are substantially the same as those of the first embodiment.

In the second embodiment, since the basic configuration is the same as that of the first embodiment, the same functions and effects as those of the first embodiment are achieved.

Although the embodiments of the motor according to the present invention have been described above, the present invention is not limited to these embodiments, and various changes and modifications can be made without departing from the scope of the present invention.

[0040]

According to the motor of the first aspect of the present invention, oil oozing out of the sleeve bearing scatters into this oil space, and the scattered oil penetrates into the inside from one end face of the sleeve bearing through this oil space. Therefore, scattering and outflow of oil to the outside can be suppressed, and the life of the sleeve bearing can be extended. Further, since the radially outer peripheral surface of the oil space is substantially closed, even if the motor is used in a horizontal state, it is possible to suppress the exuded oil from scattering and flowing out.

Further, according to the motor of the second aspect of the present invention, it is possible to increase the surface area of one end surface of the sleeve bearing to promote the penetration of oil into the sleeve bearing.

According to the motor of the third aspect of the present invention, the oil hardly adheres to the surface of the plate-shaped member, and the oil scattered in the oil space can permeate into the inside of the sleeve bearing.

Further, according to the motor of the fourth or fifth aspect of the present invention, when the rotating shaft of the rotor is inserted into the sleeve bearing, the air in the sleeve bearing can be released to the outside,
Thereby, the rotating shaft can be easily mounted on the sleeve bearing.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of a motor according to the present invention.

FIG. 2 is a partially enlarged sectional view showing a main part of the motor of FIG.

FIG. 3 is an enlarged front view showing a plate-shaped member of the motor shown in FIG. 1;

FIG. 4 is a sectional view showing a second embodiment of the motor according to the present invention.

FIG. 5 is a partially enlarged sectional view showing a main part of the motor of FIG. 4;

FIG. 6 is a partial sectional view showing a part of a conventional motor.

[Explanation of symbols]

 32 stationary member 34 rotor 38, 38A cylindrical support member 40 rotor body 46 rotating shaft 48, 48A sleeve bearing 50 sliding bearing piece 58 rotor magnet 60 stator 72, 72A annular protrusion 74, 74A plate member 76 oil space 78 annular groove 94 Communication groove

Claims (5)

[Claims] 1. A motor comprising: a stationary member having a cylindrical support portion; a rotor having a rotary shaft portion; and a sleeve bearing interposed between the cylindrical support portion and the rotary shaft portion. An annular projection protruding outward in the axial direction is provided on one end surface of the bearing, and a plate-like member is provided outside one end of the sleeve bearing. The plate-like member contacts the annular projection of the sleeve bearing. A motor mounted on the cylindrical support portion so as to be in contact with the one end surface of the sleeve bearing to form an oil space. 2. The motor according to claim 1, wherein an annular groove is formed on the one end surface of the sleeve bearing at a position radially inside the annular projection. 3. The motor according to claim 1, wherein the plate-shaped member is formed of a material having oil repellency. 4. An annular recess is formed at an outer peripheral portion of said one end of said sleeve bearing, and an air escape groove extending from said annular recess to a predetermined portion is formed at an outer peripheral surface of said sleeve bearing. The motor according to any one of claims 1 to 3, wherein the plate-shaped member is formed with a notch for allowing air in the annular concave portion to escape. 5. An annular recess is formed at an outer peripheral portion of said one end of said sleeve bearing, and an air escape groove extending from said annular recess to a predetermined portion is formed at an outer peripheral surface of said sleeve bearing. The motor according to any one of claims 1 to 3, wherein the annular projection of the sleeve bearing has a communication groove communicating the annular recess with the oil space.