JP2002048139A - Bearing device and motor provided with bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To restrain dispersion of lubricant sprang out of an axial edge of an oil-impregnated bearing to the outside of the bearing devise and to control the running off of the lube oil, without increasing the number of part items, in a bearing device provided with an oil-impregnated bearing. SOLUTION: A recess 22a extending approximately coaxially with a rotating shaft 5 is formed on an end face axially of the oil retaining bearing 22 supporting the rotating shaft 5. Therefore, even if the lube oil is sprang out from the axial end face of the bearing 22 along the rotating shaft 5 and the lube oil is dispersed due to centrifugal force, the dispersed lube oil adheres on the inside surface of the recess 22a provided on the bearing 22 and is recovered into the bearing 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing device for supporting a rotating shaft such as a motor.

[0002]

2. Description of the Related Art Conventionally, as a bearing device for supporting a rotating shaft such as a motor, for example, the one shown in FIG. 4 is known.
As shown in the figure, the bearing device 51 is configured in a bearing housing portion 52 formed in a substantially cylindrical shape with a bottom along the axis of the rotating shaft 50 from the case of the motor. An oil-impregnated bearing 53 whose one end is supported;
2, a lock washer 54 that supports the other end of the oil-impregnated bearing 53, a cup washer 55 that is fixed to the rotating shaft 50 of the motor and covers an axial end of the oil-impregnated bearing 53, and the other end of the oil-impregnated bearing 53. Thrust receiving washers 56 and 57 are attached to the rotating shaft 50 so as to abut (slidably contact) the end surface and receive the thrust load of the rotating shaft 50.

[0003] The oil-impregnated bearing 53 is formed of a porous sintered metal and is filled with lubricating oil. Therefore, when the rotating shaft 50 of the motor rotates, the rotating shaft 50 slides on the inner peripheral surface of the oil-impregnated bearing 53 to generate a negative pressure or generate frictional heat, and the frictional heat causes the bearing 53 to rotate. As the lubricating oil expands, its viscosity decreases, and the lubricating oil flows out on the inner peripheral surface of the bearing 53. Then, an oil film is formed on the inner peripheral surface of the bearing 53 by the lubricating oil that has flowed out, so that the rotating shaft 50 rotates smoothly.

[0004]

The oil-impregnated bearing 5
In No. 3, lubricating oil flows out from the end in the axial direction along the rotating shaft 50, though the amount is small. In particular, as described above, when the thrust receiving washers 56 and 57 slidably contact the ends in the axial direction, frictional heat is generated at the slidably contacting portions, and a large amount of lubricating oil flows out. Then, a part of the lubricating oil that has flowed out reaches the outer peripheral edges of the thrust receiving washers 56 and 57 and is scattered by the centrifugal force due to its own rotation. Therefore, there is a problem that the lubricating oil decreases and the life of the oil-impregnated bearing 53 is shortened.

Further, most of the lubricating oil scattered from the outer peripheral edges of the thrust receiving washers 56 and 57 is shielded by the cup washer 55, so that further scattering to the outside is suppressed. Is applied to, for example, a motor of a type in which cooling air is forcibly fed into the motor, a part of the lubricating oil is carried to the commutator 58 of the motor without adhering to the cup washer 55 by the cooling air, and 58. Thus, the commutator 5
If the lubricating oil adheres to the commutator 58, the commutator 58 may be clogged, causing a short circuit, abnormal noise, abnormal wear of the commutator 58, and the like. Had to be reduced.

Therefore, in order to solve such a problem,
As shown in FIG. 5, for example, using two plates 61 and 62, a passage (space) formed by the cup washer 55, the lock washer 54, and the bearing accommodating portion 52 may be formed into a complicated maze structure. However, the number of parts is increased and this is not an effective means.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object thereof is to provide a bearing device having an oil-impregnated bearing and a motor having the bearing device without increasing the number of parts. Another object of the present invention is to prevent the lubricating oil that has flowed out from the axial end of the oil-impregnated bearing from scattering outside the bearing device, and to suppress the outflow of the lubricating oil.

[0008]

In order to solve the above-mentioned problems, an invention according to claim 1 is a bearing device provided with an oil-impregnated bearing for rotatably supporting a rotating shaft, wherein the oil-impregnated bearing is provided with an oil-impregnated bearing. Formed a concave portion extending substantially coaxially with the rotation shaft at an axial end.

According to a second aspect of the present invention, there is provided a bearing device provided with an oil-impregnated bearing that rotatably supports a rotating shaft and a thrust receiving washer that receives a thrust load of the rotating shaft abuts an axial end. In the oil-impregnated bearing, a concave portion is formed at the axial end to extend substantially coaxially with the rotating shaft and to accommodate a part or all of the thrust receiving washer in the axial direction.

According to a third aspect of the present invention, in the bearing device according to the second aspect, two or more thrust receiving washers are used, and among the washers, the thrust receiving washers are disposed outside as viewed from the bearing. The diameter of the washer was larger than that of the inner washer.

According to a fourth aspect of the present invention, in the bearing device according to any one of the first to third aspects, a cup washer fixed to the rotating shaft and provided so as to cover an axial end of the oil-impregnated bearing. With.

According to a fifth aspect of the present invention, there is provided a motor including the bearing device according to any one of the first to fourth aspects. (Operation) According to the first aspect of the present invention, the oil-impregnated bearing that supports the rotating shaft is formed with a concave portion extending substantially coaxially with the rotating shaft at an axial end. Therefore, even if lubricating oil flows out from the axial end of the bearing along the rotating shaft, and the lubricating oil is scattered due to centrifugal force, the scattered lubricating oil adheres to the inner surface of the recess provided in the bearing and the lubricating oil adheres to the bearing. Collected inside. Therefore, the lubricating oil from the axial end of the oil-impregnated bearing is suppressed from scattering to the outside. Furthermore, since the lubricating oil can be prevented from scattering to the outside by providing the concave portion in the bearing, the number of parts does not increase. Moreover, since the scattered lubricating oil can be positively collected on the inner peripheral surface of the concave portion and the outflow of the lubricating oil can be suppressed, the depletion of the lubricating oil can be suppressed as much as possible, and the life of the oil-containing bearing can be extended.

According to the second aspect of the present invention, in the oil-impregnated bearing for supporting the rotating shaft, the axial direction of the thrust receiving washer extending substantially coaxially with the rotating shaft at the axial end and receiving the thrust load of the rotating shaft. Is formed to accommodate a part or all of. The bearing end that this thrust receiving washer contacts
Friction heat is generated during the sliding contact, and a large amount of lubricating oil flows out. Then, a part of the lubricating oil that has flowed out may be transmitted to the outer peripheral portion of the washer and scattered by centrifugal force generated by its own rotation. However, since the washer is accommodated in the concave portion provided in the bearing, the lubricating oil scattered from the outer peripheral portion of the washer adheres to the inner surface of the concave portion provided in the bearing and is collected in the bearing. Therefore, the lubricating oil from the axial end of the oil-impregnated bearing is suppressed from scattering to the outside. Furthermore, since the lubricating oil can be prevented from scattering to the outside by providing the concave portion in the bearing, the number of parts does not increase. Moreover, since the scattered lubricating oil can be actively collected on the inner peripheral surface of the concave portion and the outflow of the lubricating oil can be suppressed, the exhaustion of the lubricating oil can be suppressed as much as possible, and the life of the oil-containing bearing can be extended.

According to the third aspect of the present invention, a large-diameter washer is disposed outside of the plurality of thrust receiving washers as viewed from the bearing, so that the lubricating oil transmitted along the outer peripheral portion of the inner washer is removed. The end face of the large diameter washer prevents further transmission to the outside in the axial direction. Also, even if the lubricating oil scatters from the outer peripheral portion of the inner washer, the large diameter washer prevents the lubricating oil from being further scattered outward in the axial direction, and is guided so as to adhere to the inner surface of the recess provided in the bearing. Is done.

According to the fourth aspect of the present invention, since the cup washer provided to cover the axial end of the oil-impregnated bearing is fixed to the rotating shaft, the lubricating oil scatters outside the recess provided in the bearing. Even so, the scattered lubricant adheres to the cup washer. Therefore, the scattering of the lubricating oil to the outside is further suppressed.

According to the fifth aspect of the present invention, the first aspect is provided.
By providing the bearing device according to any one of (1) to (4),
Without increasing the number of parts, the lubricating oil from the axial end of the oil-impregnated bearing is scattered to the outside and the outflow of the lubricating oil is suppressed, so the lubricating oil is applied to the motor components, for example, the commutator of the DC motor. Adhesion is reduced, and various problems due to adhesion of lubricating oil to the commutator are reduced. In addition, since the number of parts does not increase, an increase in the cost of the motor can be suppressed.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, a DC motor 1 includes a yoke housing 2 and an end housing 3.
The armature 4 is rotatably accommodated in the space defined by the above. The rotating shaft 5 of the armature 4 is rotatably supported by bearing devices 6 and 7. A plurality of permanent magnets 8 are fixed to the inner peripheral surface of the yoke housing 2 so as to surround the armature 4. At one end of the rotating shaft 5 (on the bearing device 7 side),
A commutator 10 that is in sliding contact with the brush 9 is attached.
A driving current is supplied to the brush 9 from the outside, and when the driving current is supplied to the coil winding of the armature 4 via the commutator 10, the armature 4 rotates.

Next, details of the structure of the bearing device 7 on the commutator 10 side will be described with reference to FIG. As shown in FIG. 2, the bearing device 7 is configured in a bearing accommodating portion 21 formed in the end housing 3, and includes an oil-impregnated bearing 22, a lock washer 23, a cup washer 24, and two thrust receiving washers. 25 and 26 are provided.

The bearing accommodating portion 21 is formed in a substantially cylindrical shape with a bottom along the axis of the rotary shaft 5, and further has a supporting recess 21a formed at the bottom. The support recess 21a is
The opening side is widened, and the inner peripheral surface has a substantially hemispherical shape. The support recess 21a is provided with an oil-impregnated bearing 22.
Support one end side.

The oil-impregnated bearing 22 is formed of a porous sintered metal and is filled with lubricating oil. The oil-impregnated bearing 22 is formed in a substantially cylindrical shape, and has a curved surface such that the outer peripheral surfaces at both ends in the axial direction are in close contact with the support recess 21a and the support recess 23a of the lock washer 23 described later.

On the opening side (commutator 10 side) of the bearing housing 21 of the oil-impregnated bearing 22, a housing recess 22a extending coaxially with the rotary shaft 5 is formed. This accommodation recess 2
2a is provided for accommodating at least one washer 25 out of two identically shaped thrust receiving washers 25, 26 receiving the thrust load of the rotating shaft 5. The other end of the oil-impregnated bearing 22 is supported by a lock washer 23.

The lock washer 23 is formed in an annular shape and is press-fitted and fixed to the opening side of the bearing housing 21. A support recess 23 a for supporting the other end of the oil-impregnated bearing 22 is formed in the inner periphery of the lock washer 23. The support recess 23a is open at the bottom side of the bearing accommodating portion 21, the opening side is widened, and the inner peripheral surface has a substantially hemispherical shape. The oil-impregnated bearing 22 supported by the support recess 23a of the lock washer 23 and the support recess 21a of the bearing accommodating portion 21 is supported so as to be tiltable with respect to the axial direction from its shape, and can be automatically aligned. It has become.

The bearing housing 21 of the lock washer 23
A cup washer 24 is arranged on the opening side. The cup washer 24 is formed in an annular shape, and an inner peripheral portion thereof is press-fitted and fixed to the rotating shaft 5. The cup washer 24
The outer peripheral portion is bent to the bottom side of the bearing housing portion 21,
The oil-impregnated bearing 22 is provided so as to substantially cover the other end side (including the washers 25 and 26).

In the bearing device 7 configured as described above, when the rotating shaft 5 rotates, the rotating shaft 5 slides on the inner peripheral surface of the oil-impregnated bearing 22 to generate a negative pressure or generate frictional heat. The generated lubricating oil in the bearing 22 expands due to the frictional heat and the viscosity of the lubricating oil decreases, so that the lubricating oil flows into the inner peripheral surface of the bearing 22. Then, an oil film is formed on the inner peripheral surface of the bearing 22 by the lubricating oil that has flowed out, so that the rotating shaft 5 rotates smoothly.

At this time, the thrust receiving washers 25 and 26 are in sliding contact with the axial end of the bearing 22. Then, frictional heat is generated in the sliding contact portion, and a large amount of lubricating oil flows out. And some of the lubricating oil that grew out like this
When the washer 25 is transmitted to the outer peripheral edge of the thrust receiving washer 25 and rotates together with the rotating shaft 5, lubricating oil is scattered from the outer peripheral portion of the washer 25 by centrifugal force. However, in the present embodiment, the washer 25 is
The lubricating oil scattered from the outer peripheral portion of the washer 25 adheres to the inner peripheral surface of the accommodating concave portion 22a and is collected in the bearing 22 because it is accommodated in the second accommodating concave portion 22a. Therefore, scattering of the lubricating oil to the outside of the bearing device 7 is suppressed as much as possible.

In addition, even if a part of the lubricating oil is transmitted to the washer 26 side and scatters from the outer peripheral portion of the washer 26, the scatter of the lubricating oil further outward is suppressed by the cup washer 24. As described above, in the present embodiment, by combining with the cup washer 24, the scattering of the lubricating oil to the outside of the bearing device 7 can be further suppressed.

As a result, in the present embodiment, the lubricating oil is prevented from being carried to the commutator 10 of the motor 1 and adhered to the commutator 10 as much as possible. The clogging of the child 10 is reduced,
Generation of abnormal noise, abnormal wear of the commutator 10, and the like are prevented.

Further, in the present embodiment, the concave portion 2 is formed in the bearing 22.
By providing 2a, the lubricating oil can be prevented from scattering outside, so that the number of parts does not increase. In addition, since the scattered lubricating oil can be actively collected on the inner peripheral surface of the concave portion 22a and the outflow of the lubricating oil can be suppressed, the exhaustion of the lubricating oil can be suppressed as much as possible, and the life of the oil-bearing bearing 22 can be extended. .

As described above, according to the present embodiment, the following effects are obtained. (1) In the present embodiment, the oil-impregnated bearing 2 that supports the rotating shaft 5
2 at the axial end thereof, the rotary shaft 5 extends substantially coaxially with the rotary shaft 5.
Thrust receiving washers 2 that receive the thrust load of
5 and 26, a receiving recess 22a for receiving at least one washer 25 is formed. Therefore, when a portion of the lubricating oil that has flowed out from the axial end of the bearing 22 is transmitted to the outer peripheral portion of the washer 25 and scattered by centrifugal force generated by its own rotation, the lubricating oil scattered from the outer peripheral portion of the washer 25 It adheres to the inner surface of the concave portion 22 a provided on the base 22 and is collected in the bearing 22. Accordingly, it is possible to suppress the lubricating oil from scattering outside the bearing device 7. As a result, the lubricating oil is carried to the commutator 10 of the motor 1 and
Is reduced as much as possible, and the clogging of the commutator 10 due to the adhesion of the lubricating oil to the commutator 10 is reduced, thereby preventing the occurrence of a short circuit, abnormal noise, abnormal wear of the commutator 10, and the like. can do.

(2) In this embodiment, the recesses 2 are formed in the bearing 22.
By providing 2a, the lubricating oil can be prevented from scattering outside, so that the number of parts does not increase. Therefore, an increase in the cost of the motor 1 can be suppressed.

(3) In the present embodiment, the scattered lubricating oil can be actively collected on the inner peripheral surface of the concave portion 22a and the outflow of the lubricating oil can be suppressed, so that the depletion of the lubricating oil can be suppressed as much as possible.
The life of the oil-impregnated bearing 22 can be extended.

(4) In the present embodiment, since the cup washer 24 is provided to cover the axial end of the oil-impregnated bearing 22, even if the lubricating oil scatters outside the concave portion 22a provided in the bearing 22, it is scattered. The lubricating oil adheres to the cup washer 24. Therefore, scattering of the lubricating oil to the outside of the bearing device 7 is further suppressed.

The embodiment of the present invention may be modified as follows. In the above embodiment, the housing recess 2 provided in the oil-impregnated bearing 22
2a is formed so as to extend coaxially with the rotating shaft 5 and to accommodate at least one washer 25 of the thrust receiving washers 25 and 26, but is formed exactly coaxially with the rotating shaft 5. It is not necessary. Also, the accommodation recess 22a
May be formed to a depth that accommodates all the washers 25 and 26 in the axial direction.

In the above embodiment, two washers 25 and 26 having the same shape are used, but the number and shape of the washers are not limited to these. For example, as shown in FIG. That is, in the embodiment shown in FIG. 3, two thrust receiving washers 27 and 28 are used, and the diameter of the washer 28 disposed outside the bearing 22 is larger than that of the inner washer 27. Therefore, it is possible to prevent the lubricating oil transmitted along the outer peripheral portion of the inner washer 27 from being further transmitted to the outside in the axial direction by the end face of the large diameter washer 28.
Further, even if the lubricating oil scatters from the outer peripheral portion of the inner washer 27, the lubricating oil is prevented from being further scattered outward in the axial direction by the end face of the large diameter washer 28.
2a is guided so as to adhere to the inner surface. Therefore, the scattered lubricating oil can be reliably collected in the bearing 22.

Alternatively, the two washers 27 and 28 may be integrated into one single washer. That is, the washer includes a large-diameter portion and a small-diameter portion, and the washer is arranged such that the large-diameter portion is outside when viewed from the bearing 22. Even in this case, the same effect as in the embodiment of FIG. 3 can be obtained.

A bearing device which receives the thrust load of the rotary shaft 5 by other means without using the washers 25 to 28, for example, a step is provided on the rotary shaft 5 and the step
The present invention may be applied to a bearing device or the like which comes into contact with two ends to receive a thrust load of the rotating shaft 5. Even in this case, even if lubricating oil flows out from the axial end of the bearing 22 along the rotating shaft 5 and the lubricating oil is scattered by centrifugal force, the scattered lubricating oil is not removed from the recess 22 a provided in the bearing 22. It adheres to the inner surface and is collected in the bearing 22. Therefore, similarly to the above embodiment, the lubricating oil from the axial end of the oil-impregnated bearing 22 is suppressed from scattering to the outside. Moreover, by providing the bearing 22 with the concave portion 22a, it is possible to prevent the lubricating oil from scattering outside, so that the number of parts does not increase.

In the above embodiment, the cup washer 24
Are shown in FIG. 2 as a shape and a fixed portion, but the present invention is not limited to this shape and the fixed portion. For example, the cup washer 24 may be fixed to the bearing housing 21 side. When the cup washer 24 is fixed to the rotating shaft 5 as in the above embodiment, the lubricating oil causes the rotating shaft 5 to move the commutator 10.
Even if the lubricating oil is transmitted to the side, the lubricating oil can be surely prevented from being transmitted to the commutator 10 side. Further, such a cup washer 24 may not be particularly provided, and may be omitted.

In the above embodiment, the oil-impregnated bearing 22 is supported between the bottom of the bearing housing 21 and the lock washer 23 so as to be tiltable with respect to the axial direction. It is not something to be done. For example, it may not be possible to tilt. Further, the inner diameter of the bearing housing 21 may be set slightly smaller than the outer diameter of the oil-impregnated bearing 22 without using the lock washer 23, and the bearing 22 may be pressed into the bearing housing 21.

In the above embodiment, the rotating shaft 5 of the motor 1
However, the present invention may be applied to a bearing device of a rotating shaft other than a motor. The technical ideas other than the claims that can be understood from the above embodiments are described below.

(A) In the bearing device according to claim 2, the thrust receiving washer has a large diameter portion and a small diameter portion, and the washer is arranged so that the large diameter portion is located outside the bearing. A bearing device comprising: With this configuration, the same effect as that of the second aspect can be obtained.

[0041]

As described in detail above, according to the present invention,
In a bearing device equipped with an oil-impregnated bearing and a motor equipped with the bearing device, it is possible to suppress the lubricating oil flowing out from the axial end of the oil-impregnated bearing from scattering to the outside of the bearing device without increasing the number of parts. Outflow of lubricating oil can be suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a motor according to an embodiment.

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

FIG. 3 is an enlarged sectional view of a main part of another example of a motor.

FIG. 4 is a sectional view of a conventional bearing device.

FIG. 5 is a cross-sectional view of another conventional bearing device.

[Explanation of symbols]

5: rotating shaft, 7: bearing device, 22: oil-impregnated bearing, 22a ...
Housing recess as recess, 24 ... cup washer, 25-
28 ... Thrust receiving washer.

Claims (5)

[Claims] 1. A bearing device comprising an oil-impregnated bearing (22) for rotatably supporting a rotary shaft (5), wherein the oil-impregnated bearing (22) has an axial end portion on which the rotary shaft (5) is attached. A bearing device characterized by forming a recess (22a) extending substantially coaxially with the bearing. 2. An oil-impregnated bearing (22) rotatably supporting a rotating shaft (5) and having a thrust receiving washer (25-28) receiving a thrust load of the rotating shaft (5) abutting on an axial end. The oil-impregnated bearing (22) has an axial end that extends substantially coaxially with the rotary shaft (5), and the thrust receiving washer (2)
5 to 28) to accommodate a part or all in the axial direction.
A bearing device characterized by forming 2a). 3. The bearing device according to claim 2, wherein two or more thrust receiving washers (27, 28) are used.
A bearing device characterized in that a washer (28) disposed outside as viewed from the bearing (22) has a larger diameter than an inner washer (27). 4. The cup washer according to claim 1, wherein the cup washer is fixed to the rotating shaft (5) and provided to cover an axial end of the oil-impregnated bearing (22). 2
4) A bearing device comprising: 5. A motor comprising the bearing device (7) according to claim 1.