JP4276291B2 - motor - Google Patents

Description

  The present invention relates to a motor provided with a sleeve bearing.

  A conventional motor provided with a sleeve bearing has a configuration shown in FIG. 6, for example. With reference to FIG. 6, the motor is composed of a stationary member 2 and a rotor 4 that is rotatable relative to the stationary member 2. The stationary member 2 includes a mounting bracket 6 and a cylindrical support member 8, and the other 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 attached to the rotor body 10, and a stator 16 is attached to the cylindrical support member 8 so as to face the rotor magnet 14.

  Between the rotary shaft 12 of the rotor 4 and the cylindrical support member 8 of the stationary member 2, a sleeve bearing 18 for supporting a radial load and a sliding bearing piece 20 for supporting a thrust load are provided. Yes. The sleeve bearing 18 is made of a porous material and contains lubricating oil therein.

  In such a motor, when the rotor 4 rotates in a predetermined direction, the oil in the sleeve bearing 18 oozes out to the inner peripheral surface by the pumping action of the rotating rotating shaft 12. When the amount of oil oozing increases, the oil scatters to the surroundings due to centrifugal force, the oil contained in the sleeve bearing 18 decreases, and the life of the sleeve bearing 18 significantly decreases.

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

  In the motor having such a configuration, the oil oozed from the sleeve bearing 18 is transmitted through the rotary shaft 12 to the plate-like member 22 and is scattered radially outward from the rotating rotary shaft 12 and / or the plate-like member 22. The scattered oil flows down along the inner peripheral surface of the protruding end 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 splashed oil and to keep the life of the sleeve bearing 18 long.

Japanese Patent Laid-Open No. 5-130754 JP-A-6-269142

  When this motor is used in a vertical state (in a state where the rotary shaft 12 extends in the vertical direction), as understood from FIG. 6, the oil oozed from the sleeve bearing 18 circulates as described above to suppress the decrease in oil. it can. However, when the motor is used in a horizontal state (in a state where the rotating shaft 12 extends horizontally), the oil scattered from the plate-like member 22 to the protruding end portion 24 of the cylindrical support member 18 does not flow toward the sleeve bearing 18. However, the oil flows out from the projecting end 24 and the above-described circulation of oil is not performed. Therefore, there is a problem that oil is remarkably reduced and the life of the sleeve bearing 18 is shortened.

  An object of the present invention is to provide a motor capable of achieving the circulation of oil that has exuded even when the motor is used in a horizontal state, thereby extending the life of the sleeve bearing.

  Another object of the present invention is to discharge the air in the stationary member to one end side.

According to a first aspect of the present invention, there is provided a stationary member including a cylindrical support portion and a sleeve bearing that is open at one end in the axial direction and closed at the other end, a rotor having a rotary shaft portion, the cylindrical support portion, and the rotary shaft. A motor comprising a sleeve bearing interposed between the parts,
A plate-like member is disposed on one end side from the sleeve bearing,
The outer peripheral surface of the plate-like member is attached to the inner peripheral surface of the cylindrical support portion, and the inner peripheral surface of the plate-like member is opposed to the outer peripheral surface of the rotary shaft portion, and the rotary shaft portion and the opening are formed. Forming,
One end side of the sleeve bearing and the other end side of the plate-like member are in contact with each other, and a radial communication hole extending in the radial direction is formed in a portion where the sleeve bearing and the plate-like member are in contact with each other.
Between the sleeve bearing and the cylindrical support portion, an axial communication hole that communicates with the radial communication hole and extends in the axial direction is formed.
The other end side of the closed sleeve bearing and the opening communicate with each other through the radial communication hole and the axial communication hole.

In the motor according to claim 2 of the present invention, a groove extending in the axial direction is formed on the outer peripheral surface of the sleeve bearing,
The axial communication hole is formed by mounting the sleeve bearing on the cylindrical support portion.

In the motor according to claim 3 of the present invention, a groove extending in the radial direction is formed on one end side of the sleeve bearing,
The radial communication hole is formed by the plate-shaped member abutting against one end side of the sleeve bearing.

In the motor according to claim 4 of the present invention, an annular recess connected to the one end surface of the sleeve bearing and the outer peripheral surface of the sleeve bearing is formed on the outer peripheral portion of the sleeve bearing.
The annular recess communicates with the radial communication hole and the axial communication hole.

  In the present invention, the air on the other end side of the sleeve bearing can be discharged well from the opening on the one end side.

  Hereinafter, an embodiment of a motor according to the present invention will be described with reference to FIGS. 1 is a cross-sectional view showing a first embodiment of a motor according to the present invention, FIG. 2 is a partially enlarged cross-sectional view showing a main part of the motor of FIG. 1, and FIG. 3 is a cross-sectional view of the motor of FIG. It is a front view which expands and shows a plate-shaped member.

  Referring to FIG. 1, the illustrated motor includes a stationary member 32 attached to, for example, a drive device that drives a disk, and a rotor 34 that is rotatable relative to the stationary member 32. 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 the other end of the cylindrical support member 38 (which constitutes the cylindrical support part) is fixed to the circular opening by, for example, press fitting. The cylindrical support member 38 may be formed integrally with the mounting bracket 36.

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

  The rotating shaft 46 of the rotor 34 is rotatably supported by the cylindrical support member 38 via a sleeve bearing 48 and a sliding bearing piece 50. The sleeve bearing 48 is referred to as an oil-impregnated bearing, and is formed of a porous material such as a sintered alloy, and contains lubricating oil therein. The sleeve bearing 48 is attached to the inner peripheral surface of the cylindrical support member 38 by, for example, press fitting. The sliding bearing piece 50 is attached to the other end of the cylindrical support member 38. In this embodiment, the other end portion of the cylindrical support member 38 is provided with a large inner diameter portion 52 having a somewhat larger inner diameter, and slightly inward in the axial direction (vertical direction in FIG. 1) from the large inner diameter portion 52. An annular holding protrusion 54 that protrudes inward in the radial direction is provided at an interval. A blocking support member 56 is disposed on the large inner diameter portion 52 of the cylindrical support member 38, and the other end surface of the cylindrical support member 38 is fixed to be in contact with the shoulder portion of the large inner diameter portion 52 by performing a caulking process. Is done. The sliding bearing piece 50 is disposed inside the closing support member 56. The sliding bearing piece 50 has a disc shape, and has an outer diameter larger than the inner diameter of the annular holding projection 54 and a thickness slightly smaller than the interval between the closing support member 56 and the annular holding projection 54. Has been. Thus, 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 by configuring in this way, the closing support member 56 is When fixing to the cylindrical support member 48 by caulking, it is possible to prevent a large force during processing from acting on the sliding bearing piece 50, thereby preventing deformation and the like of the sliding bearing piece 50. The sleeve bearing 48 and the configuration related thereto will be described in detail later.

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

  An annular rotor magnet 58 is mounted on the inner peripheral surface of the peripheral side wall 42 of the rotor body 40. A stator 60 is provided opposite to 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 the magnetic action of the rotor magnet 58 and the stator 60.

  Next, the sleeve bearing 48 and the related configuration will be described with reference to FIGS. 2 and 3 together with FIG. Referring mainly to FIG. 2, in this embodiment, one end surface (the upper end surface in FIGS. 1 and 2) of the sleeve bearing 48 is provided with an annular protrusion 72 protruding outward in the axial direction. The tip surface is formed substantially flat. A plate-like 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 rotating shaft 46 extends through the circular opening. The outer peripheral portion of the plate-like member 74 is fixed to the inner peripheral surface of the cylindrical support member 38 by, for example, press-fitting so as to contact the tip end surface of the annular protrusion 72. By providing the plate-like member 74 in this manner, the space between the annular protrusion 72 and the plate-like member 74 is substantially closed, and an annular oil space 76 is formed between one end surface of the sleeve bearing 48 and the plate-like member 74. It is formed. The oil space 76 is released on the inner peripheral surface facing the rotation shaft 46, and the oil transmitted through the rotation shaft 46 scatters into the oil space 76, and the scattered oil enters the inside from one end surface of the sleeve bearing 48. To penetrate.

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

  In this embodiment, an annular groove 78 is further formed in one end surface of the sleeve bearing 48, specifically, in a portion radially inward of the annular protrusion 72. The annular groove 78 has a V-shaped cross section. By forming such an annular groove 78, the surface area of the one end surface is increased, and oil penetrates from one end surface of the sleeve bearing 48 to the inside. Is promoted. Further, 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 penetration of the scattered oil into the interior is more effective. Done. The cross-sectional shape of the annular groove 78 may be any other shape such as a rectangular shape or a semicircular shape. Also, a plurality of annular grooves 78 can be provided concentrically, for example.

  In order to more effectively permeate oil from the one end face of the sleeve bearing 48, the annular protrusion 72 is provided on the outer peripheral portion of the one end face, and the area defining the oil space 76 on the one end face is increased. Is desirable. Further, it is desirable to provide an annular groove 78 on the radially inner side following the annular protrusion 78 to increase the surface area of the annular groove 78.

  An inclined surface 80 that is inclined inward in the axial direction toward the inner side in the radial direction is formed on the inner peripheral portion of 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 further configured as follows so that the rotor 34 can be easily assembled. That is, an annular recess 82 is formed in the outer peripheral portion of one end of the sleeve bearing 48 by notching a corner portion. Further, the outer circumferential surface of the sleeve bearing 48 extends from one end thereof to a predetermined portion in the axial direction. In other words, the air escape groove extends in a region of the outer circumferential surface of the sleeve bearing 48 that contacts the inner circumferential surface of the cylindrical support member 38. 84 is formed, and one end of the air escape groove 84 communicates with the annular recess 82. Further, the plate-like member 74 is formed with a notch 86 corresponding to the annular recess 82 at a part of the outer periphery thereof. 1 and 2, when the rotary shaft 46 of the rotor 34 is inserted into the sleeve bearing 48, the air in the sleeve bearing 48 is compressed by the insertion of the rotary shaft 46. However, the compressed air flows from the other end side of the sleeve bearing 48 to the annular recess 82 through the gap between the sleeve bearing 48 and the cylindrical support member 38 and the air escape groove 84, and further to the plate-like member 74. It flows out through the notch 86. Thus, since the air in the sleeve bearing 48 is removed, the rotary shaft 46 can be easily inserted into the sleeve bearing 48. One or more air escape grooves 84 can be provided in the circumferential direction of the sleeve bearing 48.

  In this motor, when the rotor 34 rotates in a predetermined direction, the oil in the sleeve bearing 48 oozes out to the inner peripheral surface by the pumping action by the rotating rotating shaft 46. The exuded oil is transmitted outward in the axial direction of the sleeve bearing 48 along the surface of the rotating shaft 46, and is scattered toward the oil space 76 by the action of centrifugal force. To penetrate. Therefore, the exuded oil is circulated through the oil space 76, and the decrease due to the scattering of the oil is remarkably suppressed, and the life of the sleeve bearing 48 can be extended.

  When such a motor is used in a horizontal state (a state in which the rotating shaft 46 extends in the horizontal direction), as understood from FIG. 1, the scattered oil is accumulated in the lower part of the oil space 76, and the accumulated oil is stored in the sleeve bearing. It penetrates into the inside from one end face of 48. Therefore, even when used in such a state, circulation of the exuded oil is achieved, and a decrease due to scattering of oil can be remarkably suppressed as in the case of using in a vertical state.

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

  Referring to FIGS. 4 and 5, in the second embodiment, one end surface of sleeve bearing 48A (the upper end surface in FIGS. 4 and 5) is axially outward as in the first embodiment. An annular protrusion 72A that protrudes from the sleeve bearing 48A is provided, and a plate-like member 74A is disposed outside one end of the sleeve bearing 48A. Furthermore, a large inner diameter portion 92 whose inner diameter is somewhat enlarged is provided at one end portion (the upper end portion in FIGS. 4 and 5) of the cylindrical support member 38A. The plate-like member 74A is placed on the shoulder formed by the large inner diameter portion 92, and is fixed to one end portion of the cylindrical support member 38A by caulking the inner peripheral portion of the large inner diameter portion 92. In this attached state, the plate-like member 74A abuts against the tip end surface of the annular protrusion 72A, the space between the annular protrusion 72A and the plate-like member 74A is closed, and the one end face of the sleeve bearing 48A and the plate-like member 74A are closed. An annular oil space 76 is formed therebetween. Accordingly, as in the first embodiment, the oil transmitted through the rotating shaft 46 scatters into the oil space 76, and the scattered oil penetrates into the inside from one end face of the sleeve bearing 48. Further, by fixing the plate-like member 74A, the space between the cylindrical support member 38A and the plate-like member 74A is also closed, and the leakage of oil to the outside can be prevented more reliably.

  In this embodiment, as in the first embodiment, the annular groove 78 and the inclined surface 80 are formed on one end surface of the sleeve bearing 48A. Furthermore, instead of providing a notch in the plate-like member 74A, a communication groove 94 extending in the radial direction is formed in the annular protrusion 72A of the sleeve bearing 48A. One communication groove 94 or two or more communication grooves 94 can be provided at intervals in the circumferential direction. As shown in FIG. 5, the communication groove 94 communicates the annular recess 82 provided at one end outer periphery of the sleeve bearing 48 </ b> A and the oil space 76.

  Thus, in the second embodiment, when the air in the sleeve bearing 48A is compressed by inserting the rotating shaft 46 in the second embodiment, the compressed air is compressed from the sleeve bearing 48A and the cylinder from the other end side of the sleeve bearing 48A. It flows into the annular recess 82 through the gap with the support member 38A and the air escape groove 84, and further escapes between the plate member 74A and the rotary shaft 46 through the communication groove 94 and the oil space 76, and is the same as described above. The effect is achieved.

  In this second embodiment, an oil repellent 96 is applied to the following locations in order to further prevent oil leakage. The inner peripheral surface of the other end portion of the cylindrical support member 38A, that is, the portion where the closing support member 56 and the sliding bearing piece 50 are mounted, and the one end portion of the cylindrical support member 38A, ie, the portion where the plate-like member 74A is attached. 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 operation and effect as those of the first embodiment are achieved.

  According to this embodiment, since the plate-like member is provided so as to contact the annular protrusion of the sleeve bearing, an oil space is formed between the one end surface of the sleeve bearing and the plate-like member. Therefore, oil that has oozed 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 scatters in 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 oil circulation is achieved. Therefore, scattering and outflow of oil to the outside can be suppressed, and the life of the sleeve bearing can be prolonged. Further, since the plate-shaped member is in contact with the annular protrusion of the sleeve bearing, the outer peripheral surface in the radial direction of the oil space is blocked, and therefore, even when the motor is used in a horizontal state, the exuded oil is scattered to the outside. , Can suppress the outflow.

  Further, according to the present embodiment, since the annular groove is formed on the one end face of the sleeve bearing, the surface area of the one end face of the sleeve bearing can be increased to promote the penetration of oil into the sleeve bearing.

  Further, according to the present embodiment, since the plate-like member is formed of an oil repellent material, oil hardly adheres to the surface of the plate-like member, and the oil scattered in the oil space is one end surface of the sleeve bearing. Penetrates into its interior.

  Further, according to the present embodiment, since the notch is formed in the plate-like member, when the rotor shaft is inserted into the sleeve bearing, the air in the sleeve bearing passes through the air escape groove and the annular recess. Therefore, the rotary shaft portion can be easily attached to the sleeve bearing.

  Further, according to the present embodiment, since the groove is formed in the annular protrusion of the sleeve bearing, when the rotor shaft is inserted into the sleeve bearing, the air in the sleeve bearing passes through the air escape groove and the communication groove. , And flows out between the plate upper member and the rotating shaft portion, and therefore, the rotating shaft portion can be easily mounted on the sleeve bearing.

  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 modifications and corrections can be made without departing from the scope of the present invention.

It is sectional drawing which shows 1st Embodiment of the motor according to this invention. It is a partial expanded sectional view which shows the principal part of the motor of FIG. It is a front view which expands and shows the plate-shaped member of the motor of FIG. It is sectional drawing which shows 2nd Embodiment of the motor according to this invention. It is a partial expanded sectional view which shows the principal part of the motor of FIG. It is a fragmentary sectional view which shows a part of conventional motor.

Explanation of symbols

32 Static member 34 Rotor 38, 38A Tubular support member 40 Rotor main body 46 Rotating shaft 48, 48A Sleeve bearing 50 Sliding bearing piece 58 Rotor magnet 60 Stator 72, 72A Annular projections 74, 74A Plate-like member 76 Oil space 78 Annular groove

Claims (4)

A motor comprising a stationary member including a cylindrical support portion and a sleeve bearing that is open at one end in the axial direction and closed at the other end, and a rotor having a rotating shaft portion,
A plate-like member is disposed on one end side from the sleeve bearing,
The outer peripheral surface of the plate-like member is attached to the inner peripheral surface of the cylindrical support portion, and the inner peripheral surface of the plate-like member is opposed to the outer peripheral surface of the rotary shaft portion, and the rotary shaft portion and the opening are formed. Forming,
One end side of the sleeve bearing and the other end side of the plate-like member are in contact with each other, and a radial communication hole extending in the radial direction is formed in a portion where the sleeve bearing and the plate-like member are in contact with each other.
Between the sleeve bearing and the cylindrical support portion, an axial communication hole that communicates with the radial communication hole and extends in the axial direction is formed.
The motor, wherein the other end side of the closed sleeve bearing and the opening communicate with each other through the radial communication hole and the axial communication hole. A groove extending in the axial direction is formed on the outer peripheral surface of the sleeve bearing,
The motor according to claim 1, wherein the axial communication hole is formed by mounting the sleeve bearing on the cylindrical support portion. A groove extending in the radial direction is formed on one end side of the sleeve bearing,
3. The motor according to claim 1, wherein the radial communication hole is formed by the plate-shaped member abutting against one end side of the sleeve bearing. An annular recess that is connected to one end surface of the sleeve bearing and the outer peripheral surface of the sleeve bearing is formed on the outer peripheral portion on the one end side of the sleeve bearing,
The motor according to claim 1, wherein the annular recess communicates with the radial communication hole and the axial communication hole.

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