JP2000046041A - Thrust bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust bearing device which prevents a collar from electrostatic charging. SOLUTION: A collar 26 is mounted on a rotary shaft 21, and opposing to the collar 26 as positioned closely, bearing pads 33a and 33b are installed for supplying lubricant oil to the load side and counter-load side, and when the rotary shaft 21 is rotated, the collar 26 remains out of contact owing to the dynamic fluid pressure of the lubricant oil existing between the collar 26 and the pads 33a and 33b. In this thrust bearing device 20, an electrostatic charge preventing member 50 is installed at the periphery of the collar 26 so as to prevent the generation of static electricity at the time of exfoliation due to the centrifugal force of the lubricant oil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thrust bearing used as a bearing for various driving devices.

[0002]

2. Description of the Related Art A conventional thrust bearing will be described below with reference to FIG.

In this figure, a rotating shaft 1 has a spacer 2
The collar 4 shown in FIG. 7 is fixed via the fastening nut 3. A load-side thrust bearing 6 is fixed to the casing 5, and a white metal 7 is cast on a surface that is in sliding contact with the collar 4.

A plurality of tapered land-shaped bearing pads 8 are formed on the sliding contact surface of the white metal 7. To the oil groove 9a of the load-side thrust bearing 6, an oil supply hole 10a provided in the casing 5, a circumferential oil groove 9b in the outer peripheral portion of the thrust bearing, an oil supply hole 10b provided corresponding to each pad,
The lubricating oil is supplied at a constant pressure via the nozzle hole 11. This lubricating oil is supplied to each pad of the taper land type, and a load capacity is generated by a wedge action. A non-load-side thrust bearing 12 is fixed to the casing 5, and lubricating oil is supplied in the same manner as the load-side thrust bearing 6.

FIG. 3 shows a sliding surface of the load-side thrust bearing 6. An inclined tapered portion 13 and a land portion 14 parallel to the surface on the sliding contact partner side are formed on the sliding contact surface of the white metal 7 with the collar 4. One set of tapered part 13
An oil groove 1 is provided between the land portion 14 and a portion where the white metal 7 does not exist between the pair of the tapered portion 13 and the land portion 14 adjacent thereto.
5 are formed.

The nozzle hole 11 is provided so as to communicate with the oil groove 15 and the oil supply hole 10. Here, the nozzle hole 11
And an oil groove 15 connected to the nozzle hole 11 and an oil groove 1
The portion composed of the tapered portion 13 adjacent to the first portion 5 and the land portion 14 adjacent to the tapered portion 13 is collectively referred to as one bearing pad 8. The lubricating oil that has entered the oil groove 15 from the nozzle hole 11 flows into the tapered portion 13 of the bearing pad 8 and further reaches the land portion 14, while generating a fluid dynamic pressure by a wedge action therebetween to generate a load capacity. Is possible.

[0007] An inner peripheral shroud 16 is formed on the inner peripheral side of the tapered portion 13 and an outer peripheral shroud 17 is formed on the outer peripheral side. Has been suppressed.

[0008] In addition to the above-mentioned thrust bearings, there are also step land type thrust bearings and other thrust bearings. In the present invention, these thrust bearings can be applied in common.

[0009]

The lubricating oil supplied between the white metal 7 and the collar 4 is finally discharged to the inner and outer peripheries of the collar 4. However, the amount of the lubricating oil removed to the outer peripheral side by the action of the centrifugal force is larger than the amount removed to the inner peripheral side.

The lubricating oil discharged to the outer peripheral side moves to the outer peripheral side due to centrifugal force from the sliding contact surface with a small gap, but moves along the surface of the collar 4 to move to the outer peripheral side, and finally the collar 4 From the outer periphery of the air.

Here, when the lubricating oil separates from the collar 4, the fact that the collar 4 and the lubricating oil are charged with the opposite signs is known as a peeling charging phenomenon. When this peeling charging phenomenon occurs in the outer peripheral portion of the collar 4, the collar 4 is charged with static electricity.

When the color 4 is charged,
Fine particles in the lubricating oil accumulate on the exfoliated and charged collar 4 due to the electrostatic action, and if this accumulation progresses, the bearing clearance is narrowed, causing a trouble.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thrust bearing device in which a collar is prevented from being charged.

[0014]

According to a first aspect of the present invention, a collar is mounted on a rotating shaft and lubricated on a load side and a counter load side in close proximity to the collar. A thrust bearing device provided with a bearing pad to which oil is supplied, wherein the collar is provided in a non-contact manner by a fluid dynamic pressure of lubricating oil present between the collar and the bearing pad when the rotary shaft is rotationally driven; A thrust bearing device, wherein an antistatic member is attached to prevent generation of static electricity at the time of separation due to centrifugal force of lubricating oil.

According to a second aspect of the present invention, the collar has a continuous curved surface shape on the outer peripheral side,
2. The thrust bearing device according to claim 1, wherein the outer periphery of the collar is coated with an antistatic member.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A first embodiment of the present invention will be described below with reference to FIGS.

The tapered land type thrust bearing device 20 of the present invention has a rotating shaft 21 having a step 22 provided with a small diameter. This step 2
A thread groove 23 is formed in the rotating shaft 21 at a position spaced by a predetermined dimension from 2 toward the small diameter side, so that the spacer 25 can be fastened by screwing a nut 24.

A collar 26 is fitted to the rotating shaft 21. In order to press the fitted collar 26 against the step 22, a spacer 25 is interposed between the nut 24 and the collar 26. I have. The spacer 25 has a predetermined length and is formed in a cylindrical shape.
By screwing 4, the spacer 25 presses the collar 26 against the step 22.

Here, a casing 27 is provided with a predetermined gap from the rotating shaft 21. The casing 27 has a configuration in which it is opposed to the circumferential direction of the rotating shaft 21 at each position with the collar 26 interposed therebetween, and the concave portions 28 and 29 are formed in portions facing the collar 26, respectively. Has become.

In FIG. 1, between the casing 27 and the rotating shaft 21, the shaft is not particularly supported in the radial direction. However, the rotating shaft is provided by a radial bearing separately provided at another position. 21 is rotatably supported. Thus, a non-contact state can be maintained with a predetermined gap between the casing 27 and the rotating shaft 21.

The casing 27 is provided to face the collar 26 with the collar 26 interposed therebetween. And this color 2
The recesses 28, 2
9 are formed. Hereinafter, the concave portion of the load-side thrust bearing 30 will be described as a first concave portion 28, and the concave portion of the non-load-side thrust bearing 31 will be described as a second concave portion 29.

A load-side thrust bearing 30 is fitted on the small diameter side of the rotary shaft 21 in the first concave portion 28. In the load-side thrust bearing 30, a white metal 32a is cast on a surface of the collar 26 facing the sliding contact surface, and the white metal 32a is processed into a predetermined shape as shown in FIG. A pad 33a is formed. In the bearing pad 33a, tapered portions 34a having inclined surfaces are formed at predetermined intervals along the circumferential direction.
The position between a and the tapered portion 34a is provided on the land 35a.

The tapered portion 34a and the land portion 35a form a pair, and the set of the tapered portion 34a and the land portion 35a and the tapered portion 34a and the land portion 35a adjacent to the set are formed. An oil groove 36a is provided. The oil groove 36a is provided in a state where the oil groove 36a is cut out in the thickness direction of the white metal 32a.

The structure for supplying the lubricating oil to the oil groove 36a and supplying the lubricating oil between the collar 26 and the bearing pad 33a when the rotary shaft 21 is rotationally driven is as follows.

A first oil supply hole 37 is formed in the casing 27 in a direction perpendicular to the rotating shaft 21. The first oil supply hole 37 is provided with a first oil supply hole 37 formed in the casing 27.
The concave portion 28 is provided such that its end is exposed, so that lubricating oil can be supplied to the first concave portion 28.

Here, the above-mentioned load-side thrust bearing 30 is fitted in the first recess 28, and a second oil supply hole 38 is also formed in the load-side thrust bearing 30. The second oil supply hole 38 formed in the load-side thrust bearing 30 has a small outer diameter portion where the second oil supply hole 38 is exposed in order to improve the supply of lubricating oil to the load-side thrust bearing 30. Circumferential oil groove 3 formed in a step shape so that
It is 9. That is, the load-side thrust bearing 30
Has a disk shape having a step.

Thus, even when the load-side thrust bearing 30 is fitted into the first concave portion 28, the lubricating oil supplied from the first oil supply hole 37 is once introduced into the circumferential oil groove 39 to be filled. Thereafter, the lubricating oil is supplied to the second oil supply hole 38.

The portion where the second oil supply hole 38 is formed is below the portion where the oil groove 36a is formed.

A nozzle hole 40 is formed toward the oil groove 36a above the inner end of the second oil supply hole 38. The nozzle hole 40 is formed so as to communicate the second oil supply hole 38 and the oil groove 36a.

Through the first oil supply hole 37, the circumferential oil groove 39, the second oil supply hole 38, and the nozzle hole 40, lubricating oil is supplied to the oil groove 36a. .

Then, lubricating oil is supplied to the oil groove 36a,
Further, when lubricating oil is supplied to the tapered portion 34a by a wedge action, the inner peripheral shroud 41a and the outer peripheral shroud 42a are provided with an inner diameter of the tapered portion 34a so as to prevent the lubricating oil from leaking outside from the tapered portion 34a. It is provided so as to surround the side end and the outer side end. The inner shroud 41a and the outer shroud 42a
The land portion 35 is positioned so as to be in close proximity to the collar 26.
It is formed to have the same height as a.

An anti-load-side thrust bearing 31 having the same configuration as that of the above-described load-side thrust bearing 30 is fitted into the second recess 29. Although lubricating oil is also supplied to the non-load-side thrust bearing 31, a third oil supply hole 43 is formed in the casing 27 to enable the supply of lubricating oil to the non-load-side thrust bearing 31 side. ing.
The third oil supply hole 43 is formed so as to be bent upward from the inner diameter side end portion, whereby the third oil supply hole 43 is exposed in the second concave portion 29.

A circumferential groove 44 is formed in the non-load-side thrust bearing 31 at a position where the third oil supply hole 43 is exposed. The circumferential groove 44, like the circumferential oil groove 39, once guides and fills the lubricating oil therein, after which the second nozzle hole 45 is filled with the lubricating oil, and then the non-load-side thrust bearing 31. The lubricating oil is supplied to the tapered portion 34b via the oil groove 36b formed in the groove.

It should be noted that, similarly to the load-side thrust bearing 30, the white metal 3
2b is cast and this white metal 32b
Is formed in a predetermined shape, so that the land portion 35b, the inner peripheral shroud 41b, and the outer peripheral shroud 42b are formed. Further, similarly to the above-described load-side thrust bearing 30, a bearing pad 33b is constituted by a taper portion (not shown), a land portion, and an oil groove 36b existing therebetween.

A collar 26 exists between the load-side thrust bearing 30 and the non-load-side thrust bearing 31.
The collar 26 is provided so as to be closely opposed to the load-side thrust bearing 30 and the non-load-side thrust bearing 31 with a small gap. The bearing 30 and the anti-thrust bearing 31 are provided in a non-contact state.

The collar 26 has a disk shape with a rectangular cross section. And this color 26
A ring-shaped anti-static pad 50 as an anti-static member is attached to the entire outer periphery. The antistatic pad 50 is formed in a ring shape so that it can be attached to the outer peripheral surface of the collar 26, and the thickness thereof is provided to be the same as the thickness of the collar 26.

The antistatic pad 50 is formed of a resin material such as polyethylene so as to prevent an electrostatic action when the lubricating oil is peeled off.

The operation and effect of the thrust bearing device 20 having the above configuration will be described below.

When the collar 26 is driven to rotate,
Load-side thrust bearing 30 and non-load-side thrust bearing 31
Is filled with lubricating oil, and the collar 26 receives a fluid dynamic pressure by a wedge action by the rotational driving of the collar 26.

By receiving this fluid dynamic pressure, a non-contact state can be maintained between the collar 26 and the load-side thrust bearing 30 and the non-load-side thrust bearing 31.

Here, the lubricating oil interposed between the collar 26 and the load-side thrust bearing 30 and the non-load-side thrust bearing 31 is supplied to the inner shroud 41a and the outer shroud 4a.
2a, the inner shroud 41a and the outer shroud 42
There is no contact between a and the collar 26, forming a sliding contact surface with a narrow gap. Therefore, with the rotation of the collar 26,
In particular, the lubricating oil moves to the outer peripheral side of the collar 26 due to the centrifugal force.

In this case, if no antistatic pad 50 is attached to the outer peripheral side of the collar 26, the lubricating oil is charged with the opposite sign and scatters when separated from the collar 26. By attaching the antistatic pad 50 to the outer peripheral side of the collar 26 as described above, the lubricating oil and the collar 26 are not charged with opposite signs.

That is, when the lubricating oil and the collar 26 are separated from each other, static electricity is charged to the collar 26 by peeling charging. In the present invention, the antistatic pad 50 is attached to the outer peripheral side of the collar 26 from which the lubricating oil is separated. As a result, it is possible to effectively prevent charging that occurs when the lubricating oil separates from the collar 26.

Thus, the fine particles in the lubricating oil can be prevented from accumulating on the collar 26 due to the electrostatic action, and the clearance between the collar 26 and the load-side thrust bearing 30 and the non-load-side thrust bearing 31 can be improved. It is possible to maintain.

Therefore, it is possible to satisfactorily function as a bearing for a long period of time.

(Second Embodiment) Hereinafter, a second embodiment of the present invention will be described with reference to FIGS.

In the thrust bearing device 60 of this embodiment, the shape of the collar 61 is different from that of the first embodiment, and the outer peripheral portion of the collar 61 is formed so as to have a substantially circular cross section. Have been. An outer surface of the collar 61 having a substantially circular shape is provided with an antistatic coating 62 to function as an antistatic member. The antistatic coating 61 is made of a resin material such as polyethylene, and has a function of preventing an electrostatic action when the lubricating oil separates, similarly to the antistatic pad 50 described above.

In this case, even if the centrifugal force increases with an increase in the number of revolutions, the antistatic coating 61 is provided at the end of the flat surface of the collar 61 in order to favorably prevent the electrostatic action due to the separation of the lubricating oil. The coating is made from.

According to the thrust bearing device 60 having such a configuration, since the outer peripheral portion of the collar 61 is formed to have a substantially circular cross section, the outer peripheral portion of the collar 61 has no edge. ing.

For this reason, even if the antistatic coating 62 is applied to the outer peripheral portion of the collar 61, no edge exists at the outer peripheral portion of the collar 61.
2, the antistatic coating 62 is hardly peeled off.

Therefore, the danger of the antistatic coating 62 being peeled off can be prevented, so that the charging that occurs when the lubricating oil separates from the collar 61 described in the first embodiment can be effectively performed over a long period of time. It is possible to prevent it.

Although the first and second embodiments of the present invention have been described above, the present invention can be variously modified. This is described below.

In the above-described embodiment, the taper land type thrust bearing device 20 has been described as the thrust bearing device. However, the present invention may be applied to, for example, a step land type thrust bearing device. Also,
The present invention may be applied to other thrust bearing devices.

Further, in the above-described embodiment, the material of the antistatic pad 50 and the antistatic coating 62 is described as a resin material such as polyethylene. Any material can be used as long as it can be prevented.

In addition, various modifications are possible without changing the gist of the present invention.

[0056]

As described above, according to the first aspect of the present invention, an antistatic member is attached to the outer peripheral portion of the collar to prevent the generation of static electricity when the lubricating oil is separated by centrifugal force. Therefore, it is possible to prevent the generation of static electricity when the lubricating oil separates from the collar. Therefore, the color is prevented from being charged with static electricity, so that it is possible to prevent the fine particles in the lubricating oil from being deposited on the color due to the separation charge.

As a result, the accumulation of fine particles in the lubricating oil on the collar can be prevented, so that the clearance of the bearing can be maintained well, and the function of the bearing can be exhibited well over a long period of time. Has become.

According to the second aspect of the present invention, the outer periphery of the collar has a continuous curved surface, and the outer periphery of the collar is coated with an antistatic member. The adhesion of the antistatic member coated on the outer peripheral side of the collar can be improved. Therefore, it is possible to prevent the risk of the coating material peeling off.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a configuration of a thrust bearing device according to a first embodiment of the present invention.

FIGS. 2A and 2B are diagrams showing a shape of a color and an antistatic pad according to the embodiment, wherein FIG. 2A is a plan view and FIG.

FIG. 3 is a view showing a sliding surface of a load-side thrust bearing according to the embodiment.

FIG. 4 is a side sectional view showing a configuration of a thrust bearing device according to a second embodiment of the present invention.

FIGS. 5A and 5B are diagrams showing shapes of a color and an antistatic pad according to the embodiment, wherein FIG. 5A is a plan view and FIG.

FIG. 6 is a side sectional view showing a configuration of a conventional thrust bearing device.

7A and 7B are diagrams showing a shape of a conventional collar, wherein FIG. 7A is a plan view and FIG. 7B is a side sectional view.

[Explanation of symbols]

 Reference numerals 20, 60: Thrust bearing device 21: Rotating shaft 26, 61 ... Collar 27: Casing 30: Load-side thrust bearing 31: Non-load-side thrust bearing 32a, 32b: White metal 33a, 33b: Bearing pad 34a, 34b: Tapered portion 35a, 35b: Land portion 36a, 36b: Oil groove 50: Antistatic pad 62: Antistatic coating

Claims (2)

[Claims] 1. A collar is attached to a rotating shaft, and bearing pads are provided to supply lubricating oil to a load side and a non-load side in close proximity to the collar, respectively. In a thrust bearing device in which the collar is provided in a non-contact manner by a fluid dynamic pressure of lubricating oil existing between bearing pads, an antistatic member is attached to an outer peripheral portion of the collar, and static electricity generated when the lubricating oil separates by centrifugal force. A thrust bearing device characterized by preventing generation of a thrust. 2. The collar according to claim 1, wherein the outer peripheral side of the collar has a continuous curved shape, and the outer peripheral side of the collar is coated with an antistatic member. A thrust bearing device as described.