JP2005061429A - Oil-impregnated metal powder sintered bearing, method and device for manufacturing the bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil-impregnated metal powder sintered bearing capable of certainly holding an oil film formed on a sliding surface, decreasing oil consumption, and suppressing the unevenness in the rotation, and provide a method and device for manufacturing the bearing capable of making the setting so that an oil leak is generated in an appropriate region and preventing its rotary shaft from causing uneven rotation and seizure. <P>SOLUTION: The oil-impregnated metal powder sintered bearing 1 is structured so that a bearing hole 4 to admit insertion of the rotary shaft 2 is formed in the bearing body 3 made of a sintered porous metal having voids internally, wherein one region on the end face 6 in the axial direction of the rotary shaft 2 is formed so that the voids opened at the end face 6 are crushed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a sintered oil-impregnated bearing capable of suitably performing lubrication with a rotating shaft inserted into a bearing hole by impregnating a bearing body with lubricating oil, and a manufacturing method and a manufacturing apparatus thereof.
[0002]
[Prior art]
Sintered oil-impregnated bearings made of porous sintered metal and impregnated with lubricating oil can be used without lubrication for a long time, have excellent durability at high temperatures, and low noise Widely used.
[0003]
This kind of sintered oil-impregnated bearing has a bearing body provided with a bearing hole, and a rotating shaft having a smaller diameter than the bearing hole is inserted into the bearing hole. The lubricating oil absorbed from a large number of fine holes in the bearing body and the lubricating oil exuded by expansion caused by frictional heat form an oil film at the sliding portion with the rotating shaft.
[0004]
By the way, in this sintered oil-impregnated bearing, since there are a large number of holes for impregnating the lubricating oil even on the sliding surface where the rotating shaft is in sliding contact, as described above, there is a gap between the rotating shaft and the sliding surface. Even if an oil film is formed, a part of the lubricating oil leaks from the holes and the hydraulic pressure is lowered, so that the local contact between the rotating shaft and the sliding surface is performed. This has the disadvantage that the coefficient of friction with respect to the rotating shaft is increased and seizure is likely to occur.
[0005]
FIG. 7 shows a conventional example of such a sintered oil-impregnated bearing 101. The sintered oil-impregnated bearing 101 is a bearing body 103 formed of a porous sintered metal including pores therein, and a bearing hole 104 is provided. The rotating shaft 102 is inserted into the bearing hole 104. To be used. Then, the holes are crushed in a partial region of the inner peripheral surface of the bearing hole 104 to form a sliding surface 105. In this manner, a method of stably holding the oil film on the sliding surface 105 that is in sliding contact with the rotating shaft 102 is used (see, for example, Patent Document 1).
[0006]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-252757 (FIG. 1)
[0007]
[Problems to be solved by the invention]
However, in the conventional sintered oil-impregnated bearing, even if the pores on the inner peripheral surface of the sintered oil-impregnated bearing are crushed, many holes remain on the outer peripheral surface or the end surface. If the lubrication of the sintered oil-impregnated bearing changes due to the outflow of impregnated oil, etc., the sliding resistance with the rotating shaft will change, causing uneven rotation, reducing the life of the sintered oil-impregnated bearing, etc. There was a problem.
[0008]
The present invention has been made in view of the above circumstances, and a first object is to reliably hold an oil film formed on a sliding surface, reduce oil consumption, and suppress rotation unevenness. An object of the present invention is to provide a sintered oil-impregnated bearing that can perform the above-described operation.
A second object of the present invention is to provide a manufacturing method and a manufacturing apparatus for manufacturing a sintered oil-impregnated bearing that can be set so that oil leakage occurs in an appropriate region and prevents rotation unevenness and seizure of the rotating shaft. is there.
[0009]
[Means for Solving the Problems]
The invention according to claim 1 is a sintered oil-impregnated bearing in which a bearing hole into which a rotating shaft is inserted is formed in a bearing body formed of a porous sintered metal including pores therein, A partial region of the end surface in the axial direction of the rotation shaft is configured to collapse the holes opened to the end surface.
[0010]
According to the present invention, the oil flow path moving from the sliding surface toward the outside of the rotating shaft end face is blocked by the sintered oil-impregnated bearing end face, and the outflow from the sintered oil-impregnated bearing end face is prevented. Further, since a part of the end face is open to the atmosphere, the amount of oil oozing can be made appropriate and a stable oil film can be held.
[0011]
The invention according to claim 2 is a sintered oil-impregnated bearing in which a bearing hole into which a rotating shaft is inserted is formed in a bearing body formed of a porous sintered metal including pores therein, At least a part of the outer peripheral surface of the bearing body has a configuration in which a hole opened in the outer peripheral surface is crushed.
[0012]
According to the present invention, at least in the portion where the pores are crushed, the oil flow path moving radially outward from the sliding surface is blocked by the outer peripheral wall surface of the sintered oil-impregnated bearing, and the oil oozes out. Is prevented.
Accordingly, the oil in the sintered oil-impregnated bearing can stay stably in the sintered oil-impregnated bearing, and the oil film formed on the sliding surface is retained.
[0013]
Invention of Claim 3 is a sintered oil impregnated bearing of Claim 2, Comprising: At least one part area | region of the end surface of the axial direction of the said rotating shaft of the said bearing main body was open | released by the said end surface. It is characterized by having a structure in which holes are crushed.
[0014]
According to this invention, the oil flow path moving toward the outer peripheral surface of the sintered oil-impregnated bearing and the end surface of the rotating shaft is blocked by the sealing portion, and the outflow of oil from the sealing portion is suppressed. Further, by releasing a part to the atmosphere without sealing all of the outer peripheral surface and the end surface, the amount of oil oozing can be made appropriate and a stable oil film can be maintained.
[0015]
Invention of Claim 4 is a manufacturing method of the sintered oil impregnated bearing which concerns on Claims 1-3, Comprising: A rotating shaft is provided in the bearing main body formed with the porous sintered metal which contains a void | hole inside. When manufacturing a sintered oil-impregnated bearing in which a bearing hole is inserted and a part of the open hole is crushed on the outer surface, the sintered oil-impregnated bearing is impregnated with oil. Insert the device rotation shaft into the bearing hole of the oil-impregnated bearing, rotate the device rotation shaft and apply a lateral pressure acting on these sintered oil-impregnated bearings in the radial direction to allow oil to exude to the outer surface of the sintered oil-impregnated bearing. The voids on the surface of the exudation area are crushed.
[0016]
According to the present invention, the same load and rotation as in actual operation are applied to the sintered oil-impregnated bearing, the physical change equivalent to that in actual operation is caused to identify the oil leaching situation, and the holes are formed. Since it is crushed, a sintered oil-impregnated bearing suitable for actual operation can be manufactured.
[0017]
According to a fifth aspect of the present invention, in the method for manufacturing a sintered oil-impregnated bearing according to the fourth aspect of the present invention, an oil containing a phosphor is used as the oil.
[0018]
According to this invention, since the phosphor is included in the oil used in the oil spill location investigation of the sintered oil-impregnated bearing, it becomes possible to more clearly identify the exudation region and determine the degree of oil spill. Can be grasped efficiently and easily.
Further, it is possible to easily confirm the oil oozing location and quantity detection while rotating the rotating shaft.
[0019]
The invention according to claim 6 is an apparatus for manufacturing a sintered oil-impregnated bearing, wherein a bearing hole into which a rotating shaft is inserted is inserted into a bearing body formed of a porous sintered metal including pores therein. An apparatus for manufacturing a sintered oil-impregnated bearing that is formed and has a part of a hole opened on its outer surface being crushed, comprising a region determining means for determining a region in which a part of the hole is crushed, and determining the region The means comprises: a first holding means for holding the sintered oil-impregnated bearing impregnated with oil in a non-rotatable manner; a second holding means for holding the device rotation shaft inserted through the sintered oil-impregnated bearing in a fixed position; A driving means for rotating the rotation shaft of the apparatus and a side pressure applying means for applying a radial side pressure to the sintered oil-impregnated bearing are provided.
[0020]
According to the present invention, the sintered oil-impregnated bearing held by the first holding means so as not to rotate is inserted into the sintered oil-impregnated bearing through the rotating shaft held in a fixed position by the second holding means. A radial side pressure is applied to the bearing by the means, and the rotating shaft is rotated by the driving means. As a result, a radial side pressure equivalent to that during actual operation and sliding resistance due to rotation of the rotating shaft are applied to the sintered oil-impregnated bearing.
As a result, it is possible to manufacture a sintered oil-impregnated bearing with an appropriate amount of seepage by determining the region where the holes should be crushed from the state of oil seepage from the bearing during actual operation.
[0021]
Invention of Claim 7 is a manufacturing apparatus of Claim 6, Comprising: The said side pressure provision means is suspended by the storage tank in which the liquid was stored, and the said 1st holding means, and in the said liquid And an immersed weight.
[0022]
According to this invention, the rotary oil shaft held at the fixed position by the second holding device is inserted into the sintered oil-impregnated bearing held so as not to rotate by the first holding device, and the weight is inserted into the first holding device. As a result, a radial side pressure equivalent to that in actual operation is applied, and the rotating shaft is rotated to identify the oil oozing state in the bearing under the same usage conditions as in actual operation.
Based on the result, a sintered oil-impregnated bearing with an appropriate amount of exudation can be produced.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of a sintered oil-impregnated bearing, a manufacturing method thereof, and a manufacturing apparatus of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram showing a first embodiment of the present invention.
The sintered oil-impregnated bearing 1 shown in this figure is formed in a substantially cylindrical shape.
This sintered oil-impregnated bearing 1 is a bearing body 3 formed of a porous sintered metal including pores therein, and a bearing hole 4 is provided in the bearing hole 4. A rotating shaft 2 slightly smaller than the hole 4 is inserted and used. And the hole part of the end surface 6 of the bearing 1 is crushed by resin coating, and the sealing part 7 is provided. Further, the sintered oil-impregnated bearing 1 is impregnated with oil for forming an oil film on the sliding surface between the rotary shaft 2.
[0024]
The sintered oil-impregnated bearing 1 is configured as described above. When the sintered oil-impregnated bearing 1 is used, the rotary shaft 2 is inserted and the rotary shaft 2 is driven by a drive source (not shown). It is something that is supported. In the sealing portion 7, the oil is prevented from oozing out, and an appropriate amount of oil oozes out from the non-sealed portion of the end face 6.
Therefore, the oil oozing of the sintered oil-impregnated bearing 1 can be set to an appropriate state, and the life of the sintered oil-impregnated bearing 1 can be extended.
[0025]
2 and 3 are views showing a second embodiment of the present invention.
In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals and the description thereof is omitted.
This embodiment is different from the first embodiment described above in that a sealing portion 8 crushed in a hole is provided not on the end face 6 but on the outer peripheral portion 5 of the bearing 1.
As shown in these drawings, a sealing portion 8 is provided by crushing a partial region of the outer peripheral surface 5 of the bearing 1, for example, a hole in a range indicated by X in FIG. Further, the sintered oil-impregnated bearing 1 is impregnated with oil for forming an oil film on the sliding surface between the rotary shaft 2.
When the rotary shaft 2 is inserted into the sintered oil-impregnated bearing 1 and the rotary shaft 2 is driven by a drive source (not shown), oil is prevented from coming out at the sealing portion 8 and the outer peripheral portion 5 is sealed. An appropriate amount of oil oozes out of the outer peripheral surface 5 from the part that is not present.
[0026]
In the above embodiment, the case where the sealing portion 7 is provided on the end surface 6 and the sealing portion 8 is provided on the outer peripheral surface 5 has been described, but the sealing portion 7 of the end surface 6 and the outer peripheral portion 5 You may make it provide in the sealing part 8 together. In this case, if the holes on the entire outer peripheral surface 5 and the end surface 6 are crushed, the oil oozes out only from the inner peripheral surface, so that the oil stays between the rotating shaft 2 and, as a result, uneven rotation occurs. Therefore, when both the outer peripheral surface 5 and the end surface 6 are sealed, it is preferable to leave a part of the holes.
Moreover, when providing the sealing part 8 in the end surface 6, you may provide in only either one of the end surfaces 6a and 6b.
[0027]
The manufacturing method of the bearing 1 mentioned above is demonstrated.
FIG. 4 is an explanatory diagram when manufacturing the bearing 1, and shows a manufacturing apparatus that can determine which part of the bearing 1 is sealed according to the usage state of the sintered oil-impregnated bearing 1. FIG.
In FIG. 4, reference numeral 50 denotes a manufacturing apparatus, reference numeral 1 denotes a bearing, reference numeral 51 denotes a first holding member (first holding means), and reference numeral 55 denotes an apparatus rotation shaft. The device rotation shaft 55 is a shaft formed slightly smaller than the bearing hole 4 of the sintered oil-impregnated bearing 1 and has the same outer diameter, material, surface roughness, etc. as the shaft actually used for the sintered oil-impregnated bearing 1. Is preferably used. The device rotation shaft 55 is inserted into the bearing hole 4 and supported at a fixed position by a second holding member (not shown), and is rotated by a driving source (not shown).
[0028]
The first holding member 51 includes an annular ring 53 that holds the bearing 1 from the outside, and arms 52 a and 52 b that are fixed to the sides of the annular ring 53. The first holding member 51 includes a bearing. 1 and a side pressure applying means 56 for applying a lower side pressure to the device rotation shaft 55 are provided.
The side pressure applying means 56 includes a weight 60 suspended from the first holding member 51, a storage tank 57, and oil 58 stored in the storage tank 57, and the weight 60 is immersed in the storage tank 57. It has a configuration. Further, the side pressure applying means 56 generates a side pressure corresponding to the radial load that the sintered oil-impregnated bearing 1 receives during actual operation.
[0029]
Said manufacturing apparatus 50 is used as follows, when determining the sealing location 5 of the sintered oil-impregnated bearing 1.
In order to determine this portion using this apparatus 50, first, the sintered oil-impregnated bearing 1 is impregnated with oil containing a phosphor.
The sintered oil-impregnated bearing 1 impregnated with oil containing phosphor is fixed to the annular ring 53 of the first holding member 51, and the device rotation shaft 55 is inserted into the bearing hole 4 of the sintered oil-impregnated bearing 1. The arms 52a and 52b are fixed at predetermined positions.
[0030]
In this case, the weight 60 suspended from the first holding member 51 is immersed in the oil 58 in the tank so as to be located a certain distance above the bottom surface of the storage tank 57, and the rotation shaft 55 rotates. The vibration is buffered by using oil 58 in the storage tank 57.
Accordingly, the first holding member 51 receives a force F obtained by subtracting the buoyancy generated by the weight 60 being immersed in the oil 58 in the tank from the gravity generated by the weight of the weight 60 in the downward direction.
[0031]
Next, with the weight 60 applied to the sintered oil-impregnated bearing 1 in the radial direction during operation, a rotational speed similar to that during operation is given to the device rotating shaft 55 by a drive source (not shown), and the sintered oil-impregnated bearing is provided. Reproduce the operating state of 1.
Regarding the oil leakage state, the oil that has been exuded is irradiated with illumination containing ultraviolet rays to emit light, and the light emission state is photographed by a camera, and the image is analyzed to identify the oil exudation location and the amount of exudation.
[0032]
FIG. 5 and FIG. 6 show the oil oozing area and the degree of oozing in the device when the device rotating shaft 55 is rotated and a 1 kg or 3 kg load is applied to the sintered oil-impregnated bearing 1. Is shown. In FIGS. 5 and 6, 11a and 11b indicate the state of oil oozing, the oil oozing amount is shown by shading such as black spots, and the darker portion has a larger oil oozing amount. Thus, according to this apparatus, since the position and state of oil leakage during operation of the sintered oil-impregnated bearing 1 can be reproduced, the oil from the sintered oil-impregnated bearing 1 is sintered on the basis of the oozing area. 1, an appropriate sealing location can be set.
[0033]
In the above embodiment, the case where the sealing portions 7 and 8 are sealed by resin coating has been described as the sealing means. However, the sealing means depends on the function of the mold in the molding process of the sintered body. Mechanical sealing, sealing by changing the density of the material, sealing by resin impregnation may be used, and the sealing effect is provided by locally changing the curvature of the outer peripheral surface 5 of the bearing 1. May be.
Moreover, it goes without saying that the phosphor includes a fluorescent substance, but it is a concept that also includes a phosphorescent substance.
[0034]
Moreover, although the said embodiment demonstrated the case where the weight 60 was immersed in the oil 58 in the storage tank 57 as a side pressure provision means of the manufacturing apparatus 50, about the side pressure provision means, urging | biasing of actuators, such as a cylinder, a spring, etc. In this case, a suspension or the like may be arranged in parallel with the actuator or the spring instead of the appreciation means using the oil 58 in the storage tank 57.
[0035]
【The invention's effect】
According to the sintered oil-impregnated bearing according to the present invention, the oil film formed on the sliding surface can be securely held, oil consumption can be reduced, and rotation unevenness can be suppressed.
In addition, according to the manufacturing method and the manufacturing apparatus according to the present invention, it is possible to set the oil oozing in an appropriate region, and it is possible to manufacture a sintered oil-impregnated bearing that prevents rotation unevenness and seizure of the rotating shaft.
[Brief description of the drawings]
FIG. 1 is a view showing a first embodiment according to the present invention, and is a front view of a sintered oil-impregnated bearing having an axial end face sealed.
FIG. 2 is a cross-sectional view of a sintered oil-impregnated bearing having a sealed outer peripheral surface, showing a second embodiment according to the present invention.
FIG. 3 is a view taken from the side of the sintered oil-impregnated bearing with the outer peripheral surface sealed, showing the first embodiment according to the present invention, with the hatched portion sealed; The hole is shown.
FIG. 4 is a diagram showing an embodiment of a manufacturing apparatus according to the present invention.
FIG. 5 is a view showing a state of oozing when oil is oozed from a sintered oil-impregnated bearing using the manufacturing apparatus according to the present invention.
FIG. 6 is a view showing a state of oozing when oil is oozed from a sintered oil-impregnated bearing using the manufacturing apparatus according to the present invention.
FIG. 7 is a view showing a conventional sintered oil-impregnated bearing, and is a cross-sectional view of a sintered oil-impregnated bearing having a sealed inner peripheral surface.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Sintered oil-impregnated bearing 3 ... Bearing main body 4 ... Bearing hole 5 ... Outer peripheral surface 6, 6a, 6b ... End surface 7 ... End surface sealing part 8 ... Outer surface sealing Hole 51... First holding means 55... Device rotation shaft 56... Side pressure applying means 57.
60 ... weight F ... side pressure acting in the radial direction

Claims (7)

A sintered oil-impregnated bearing in which a bearing hole into which a rotating shaft is inserted is formed in a bearing body formed of a porous sintered metal including voids therein,
A sintered oil-impregnated bearing characterized in that a partial region of the end face in the axial direction of the rotary shaft is formed by crushing the holes opened in the end face. A sintered oil-impregnated bearing in which a bearing hole into which a rotating shaft is inserted is formed in a bearing body formed of a porous sintered metal including voids therein,
A sintered oil-impregnated bearing, characterized in that at least a part of the outer peripheral surface of the bearing body is configured to collapse a hole opened in the outer peripheral surface. A sintered oil-impregnated bearing according to claim 2,
A sintered oil-impregnated bearing, characterized in that at least a partial region of an end face in the axial direction of the rotating shaft of the bearing body is formed by crushing the hole opened to the end face. A bearing body formed of a porous sintered metal containing voids inside has a bearing hole through which the rotating shaft is inserted, and a part of the voids opened on the outer surface is crushed. When manufacturing the oil-impregnated bearings, the sintered oil-impregnated bearing is impregnated with oil, and the device rotation shaft is inserted into the bearing hole of the sintered oil-impregnated bearing, and the device rotation shaft is rotated. A method for producing a sintered oil-impregnated bearing, comprising applying a lateral pressure acting in a radial direction to cause oil to exude to the outer surface of the sintered oil-impregnated bearing and crushing the holes in the surface of the exuded region. 5. The method for producing a sintered oil-impregnated bearing according to claim 4, wherein an oil containing a phosphor is used as the oil. A bearing body formed of a porous sintered metal containing voids inside has a bearing hole through which the rotating shaft is inserted, and a part of the voids opened on the outer surface is crushed. A device for manufacturing an oil-impregnated bearing, comprising region determining means for determining a region in which a part of the hole is crushed, wherein the region determining means holds the sintered oil-impregnated bearing impregnated with oil in a non-rotatable manner. 1 holding means, second holding means for holding the device rotation shaft inserted through the sintered oil-impregnated bearing in a fixed position, drive means for rotating the device rotation shaft, and the sintered oil-impregnated bearing in the radial direction. An apparatus for manufacturing a sintered oil-impregnated bearing, comprising: a side pressure applying means for applying a side pressure. The manufacturing apparatus according to claim 6, wherein the lateral pressure applying unit includes a storage tank in which a liquid is stored, and a weight suspended from the first holding unit and immersed in the liquid. A manufacturing apparatus characterized by.

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