JPH09137829A - Roller for roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure a life and wear resistance without needing troublesome machining by a method wherein the surface heat treatment layer of a carburization layer or a carbonitriding layer is formed on a rolling surface, a surface heat treatment layer is not formed on an end face making contact with the flange side surface of a bearing ring and not formed on a rolling or less formed than the rolling surface. SOLUTION: When carburization treatment or carbonitriding treatment is applied on a taper roller 1, an end face 3 on the large side is covered with a carbon-proofing treatment layer 5. The carbon-proofing treatment layer 5 is formed by a copper plating layer or by a coating layer of a carbon-proofing agent. When, in this state, treatment is applied on the roller 1, a surface heat treatment layer is formed on a part except the end face 3. In which case, by applying a desired machining work on the end face 3, the end face is smoothed and wear between the outer peripheral surface of the end part on the large part of an inner ring and one side surface of an out flange-form flange part is reduced and the end face 3 forms a spherical protrusion freed from turbulence and a slide contact state between the end face 3 and the one side surface of the flange part can be improved. Since the carbon-proofing treatment layer 5 is soft, the layer is easily removed. This constitution sufficiently ensures durability of the rolling surface 4, and prevents the occurrence of seizure.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION Rollers for rollers according to the present invention include tapered rollers and cylindrical rollers. The cylindrical roller also includes a needle. Of these, the tapered roller is incorporated in a tapered roller bearing to form various rotary support portions to which a large radial load and thrust load are applied. Further, the cylindrical roller is incorporated in the cylindrical roller bearing to form various rotary support portions to which a large radial load is applied without applying a large thrust load.

[0002]

2. Description of the Related Art A tapered roller bearing or a cylindrical roller bearing is incorporated in a rotary support portion of various machine devices such as machine tools and automobiles. Of these, a tapered roller bearing 1 is provided with a tapered roller 1 as shown in FIG. 5, and a cylindrical roller bearing is provided with a plurality of cylindrical rollers 2 as shown in FIG. 6, respectively, so that relative rotation between the inner ring and the outer ring is achieved. I am free. Such a taper roller 1
Alternatively, in order to improve impact resistance, wear resistance, durability, etc., the cylindrical roller 2 is carburized or carbonitrided, etc. Alternatively, a surface heat treatment layer having different properties may be provided. Conventionally, FIG.
The taper roller 1 as shown in Fig. 6 is also the cylindrical roller 2 as shown in Fig. 6.
Also, a surface heat treatment layer which is a carburized layer or a carbonitrided layer was formed on the entire surface.

[0003]

However, when a surface heat treatment layer which is a carburized layer or a carbonitriding layer is formed on the entire surface of the tapered roller 1 or the cylindrical roller 2 as in the conventional case, the tapered roller 1 or the cylindrical roller 2 is formed. The shape accuracy of the end surfaces of the rollers 1 and 2 required to improve the lubricity between the end surface of the roller 2 and the side surface of the collar portion formed on the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring,
Processing for improving the surface roughness becomes difficult. That is, a flange portion is formed on the outer peripheral surface of the inner ring or the inner peripheral surface of the outer ring forming the tapered roller bearing or the cylindrical roller bearing, and when operating the tapered roller bearing or the cylindrical roller bearing, the tapered roller or The end surface of the cylindrical roller and the side surface of the flange portion are in sliding contact with each other. Therefore, if the frictional state between these two surfaces is not good, the rotating torque of the tapered roller bearing or the cylindrical roller bearing becomes large, and not only the power loss at these tapered roller bearings or the cylindrical roller bearing portion becomes large. In extreme cases, it may cause a failure such as seizure.

In order to prevent the occurrence of such inconvenience,
The surface roughness of the end surface of the tapered roller 1 or the cylindrical roller 2 is improved (smoothed), and the end surface is adjusted to a proper shape for forming an oil film to improve the lubricity between the end surface and the side surface. Need to (reduce friction). When these processes are carried out by mechanical grinding, in the conventional case, a surface heat treatment layer which is a carburized layer or a carbonitrided layer is formed on the end surface of the tapered roller 1 or the cylindrical roller 2 as well. The work is troublesome and takes time. Therefore, the cost of the tapered roller bearing or the cylindrical roller bearing incorporating the tapered roller 1 or the cylindrical roller 2 increases. In the case where the taper roller 1 or the cylindrical roller 2 is subjected to a normal quenching treatment for hardening the whole including the inside thereof almost uniformly, the above-mentioned processing work is not so troublesome. The durability (rolling life, wear resistance) of the rolling surface of a hardened tapered roller bearing or cylindrical roller bearing cannot be ensured as much as that of a tapered roller bearing or a cylindrical roller bearing with the above heat treatment layer. .

Further, most of the heat generated by the sliding of the end surface of the tapered roller 1 or the cylindrical roller 2 with the side surface of the flange enters the sliding surface by heat conduction. The rise in the surface temperature of the sliding portion due to this heat conduction changes depending on the material components. That is,
Considering the surface temperature rise θ due to a plane moving heat source with a circular uniform distribution on the surface of a semi-infinite body, letting the heat generation amount be Q, the moving speed V
Is large (L> 3), it is expressed by the following equation. θ = 0.254Q / (λ · r · L ^1/2 ) λ: thermal conductivity r: heat source radius L: V / (2κ) κ: thermal diffusivity V: moving speed of heat source where λ and κ The value changes depending on the carbon concentration in the steel, etc., and if the other material constituents are the same, the value increases as the carbon content decreases. Therefore, the lower the carbon concentration in the steel, the smaller the surface temperature rise. In the case of each roller 1, 2 having a carburized layer or carbonitrided layer formed on the end face, the carbon amount of the surface layer on the end face of each roller 1, 2 is large, so that the end face of each roller 1, 2 and the side face of the collar are It is conceivable that the surface temperature rise during sliding will be large. If such a surface temperature rise is remarkable, it will cause seizure and the like. Therefore, it is not preferable that the surface temperature rise becomes large. The roller for a roller bearing of the present invention was invented in view of these circumstances.

[0006]

A roller for a roller bearing according to the present invention is provided with a surface heat treatment layer which is a carburized layer or a carbonitrided layer on a rolling surface, and at least an end surface which comes into contact with a side surface of a collar formed on a bearing ring. Is not provided with the surface heat treatment layer, or not provided with a surface treatment layer as much as the surface heat treatment layer provided on the rolling surface,
The shape accuracy of this end face and the workability relating to the surface roughness are improved.

As described above, the surface heat treatment layer is provided on the rolling surface and the surface heat treatment layer is not provided on the end surface which contacts the side surface of the collar, or the surface heat treatment layer is provided as much as the surface heat treatment layer provided on the rolling surface. As a method of not providing the heat treatment layer, for example, the following method can be adopted. With the carburizing treatment applied to the end face, the rolling face is subjected to carburizing treatment or carbonitriding treatment. After providing a surface heat treatment layer that is a carburized layer or carbonitriding layer on the entire surface of the roller, by removing the surface heat treatment layer formed on this end surface by performing processing such as rough grinding on the end surface of this roller, Or reduce it.

[0008]

In the case of the roller bearing roller of the present invention configured as described above, in the state where the roller bearing is configured with the inner ring and the outer ring, the pressure resistance of the rolling surface contacting the inner ring raceway and the outer ring raceway and It is possible to improve the lubricity between the end surface and the side surface of the collar portion while ensuring wear resistance. Further, in the case of the roller bearing roller of the present invention, there is no surface heat treatment layer on the end surface that contacts the side surface of the collar formed on the bearing ring, or even if it is present, the surface heat treatment layer provided on the rolling surface is Since there is not much, the carbon concentration in the surface portion of this end face is small. Therefore, it is considered that the surface temperature rise at the time of sliding between the end surface of the roller and the side surface of the collar is small. For this reason, it becomes difficult for a failure such as seizure due to an increase in the surface temperature to occur.

[0009]

FIG. 1 shows a first embodiment of the present invention in which a surface heat treatment layer is not provided on the large diameter end face 3 of a tapered roller 1 constituting a tapered roller bearing. There is.
In the state where the tapered roller bearing is configured, the large diameter side end surface 3 is
It is in sliding contact with one side surface of an outward flange-shaped collar portion formed on the outer peripheral surface of the large diameter side end portion of the inner ring. Therefore, it is necessary to improve the surface roughness of the large-diameter side end surface 3 to reduce the friction acting between the large-diameter side end surface 3 and one side surface of the collar portion. Therefore, by grinding (including polishing) the large-diameter side end face 3, the large-diameter side end face 3 is finished to be smooth.

Since one side surface of the flange is a conical or spherical concave surface, when the large-diameter side end surface 3 is simply a flat surface, the large-diameter side end surface 3 is closer to the outer peripheral edge. Only the portion is in strong contact with the one side surface. In such a state, the friction may increase. Therefore,
The large-diameter side end surface 3 is a slight spherical convex surface (having a slightly smaller radius of curvature than the radius of curvature of one side surface of the collar portion). By this processing, a wedge-shaped cross-sectional shape in which the thickness dimension becomes larger toward the outer peripheral edge of the large diameter side end surface 3 between the sliding contact surfaces of the large diameter side end surface 3 and one side surface of the flange portion, The minute gaps that it has are formed. In the minute gap having such a shape, the lubricating oil is efficiently taken in between the sliding contact surfaces as the taper roller 1 rolls, and a strong oil film is formed between the sliding contact surfaces. Let

The large-diameter side end surface 3 of the taper roller 1 has a smooth surface as described above and has a spherical convex surface which does not disturb the shape. On the other hand, the surface of the rolling surface 4 is less susceptible to damage due to contact with the inner ring raceway and the outer ring raceway,
A surface heat treatment layer which is a carburized layer or carbonitrided layer is provided. When such a surface heat treatment layer is formed even on the large-diameter side end surface 3, it is troublesome to make the large-diameter side end surface 3 smooth or to form a spherical convex surface having no irregular shape.

Therefore, in the case of this embodiment, when the taper roller 1 is carburized or carbonitrided to provide a surface heat treatment layer on the rolling surface, the end surface 3 on the large diameter side is machined. In order to improve the property, the large-diameter side end surface 3 is covered with a carbon-proof treated layer 5. Such a charcoal-proofing layer 5 can be formed by a copper plating layer or a coating layer of a charcoal-proofing agent. If the taper roller 1 is subjected to carburizing treatment or carbonitriding treatment with the large-diameter side end face 3 covered with such a carburization-preventing layer 5, the surface heat treatment is applied to the portion excluding the large-diameter side end face 3. A taper roller 1 provided with layers is obtained.

Therefore, if the large-diameter side end face 3 is subjected to desired machining, the large-diameter side end face 3 is made smooth and the friction acting between the large-diameter side end face 3 and one side surface of the flange portion. In addition, the large-diameter side end surface 3 is made into a spherical convex surface having no irregularity in shape, so that the sliding contact condition between the large-diameter side end surface 3 and one side surface of the collar portion can be improved. Since the charcoal-proof treatment layer 5 is soft, it can be easily removed at the initial stage of the machining.
By these series of operations, the tapered roller 1 having the surface heat treatment layer which is a carburized layer or carbonitrided layer on the rolling surface 4 and the large-diameter side end surface 3 having a spherical convex surface which is not disturbed in shape can be obtained. In such a tapered roller 1, since the rolling contact surface 4 is covered with the surface heat treatment layer, the durability and the like of the rolling contact surface 4 can be sufficiently secured. Further, since the sliding contact state between the large-diameter side end surface 3 and one side surface of the collar portion is improved, power loss during rotation of the tapered roller bearing can be suppressed to a small level, and seizure and other failures can be effectively prevented.

FIG. 2 shows, as a second embodiment of the present invention, a second example of a method in which a surface heat treatment layer is not provided on the large-diameter side end surface 3 of the tapered roller 1 constituting the tapered roller bearing. . In the case of this embodiment, first, a surface heat treatment layer which is a carburized layer or carbonitrided layer is provided on the entire surface of the tapered roller 1 including the large-diameter side end surface 3. Then, the large-diameter side end surface 3 of the taper roller 1 is subjected to removal processing such as rough grinding to remove the surface heat treatment layer formed on the large-diameter side end surface 3 by the chain line segment in FIG. Rough grinding does not require surface accuracy, so it can be done by using a cutting tool such as a highly rigid tool. Therefore, the work of removing the surface heat treatment layer, which is the carburized layer or the carbonitrided layer, from the surface of the large-diameter side end face 3 can be performed without trouble. If the surface heat treatment layer is removed by this rough grinding, the large diameter side end surface 3
By subjecting the large-diameter side end surface 3 to a desired machining, the friction acting between the large-diameter side end surface 3 and one side surface of the collar portion is reduced, and the large-diameter side end surface is reduced. 3 is a spherical convex surface having no irregularity in shape to improve the sliding contact condition between the large-diameter side end surface 3 and one side surface of the collar portion. In the case of the present embodiment, the anticorrosion layer 5 (FIG. 1) is formed on the end surface 3 on the large diameter side.
Since it is not necessary to form the taper, the cost of the tapered roller 1 can be reduced accordingly. Other configurations and operations are similar to those of the above-described first embodiment. The surface heat treatment layer formed on the large-diameter side end surface 3 does not necessarily have to be completely removed, and is present in a state (thinner) smaller than the surface heat treatment layer formed on the portion to be the rolling surface. If so, it is possible to reduce friction and improve the sliding contact condition.

Next, FIG. 3 shows a third embodiment of the present invention. In this embodiment, the present invention is applied to the cylindrical roller 2. In the state where the cylindrical roller bearing is configured, both end surfaces 6, 6 of the cylindrical roller 2 are brought into sliding contact with one side surface of a flange portion formed on both outer peripheral surfaces of both ends of the inner ring or both inner peripheral surfaces of both ends of the outer ring. Also in the case of this embodiment, as in the case of the first embodiment described above, the cylindrical roller 2 is carburized or carbonitrided with the carburization-preventing layers 5, 5 provided on both end surfaces 6, 6 to be processed smoothly. Then, a surface heat treatment layer which is a carburized layer or a carbonitrided layer is provided on the rolling surface 7 of the cylindrical roller 2. Other than that, the configuration and operation of the basic part of the present invention are the same as those of the first embodiment described above.

Next, FIG. 4 shows a fourth embodiment of the present invention. In this embodiment, the processing method of the second embodiment described above is applied to the cylindrical roller 2. The shape of the cylindrical roller 2 is the same as that of the third embodiment described above, and the method of processing the end faces 6 and 6 is the same as that of the second embodiment described above.

[0017]

Since the roller for roller bearing of the present invention is constructed and operates as described above, it has excellent reliability and durability, can reduce the rotational torque of the roller bearing, and can prevent seizure and the like. Roller bearings that are less prone to failure can be realized at low cost.

[Brief description of the drawings]

FIG. 1 is a side view of a tapered roller showing a first embodiment of the present invention.

FIG. 2 is a side view of the taper roller showing the second embodiment.

FIG. 3 is a side view of a cylindrical roller showing the third embodiment.

FIG. 4 is a side view of a cylindrical roller showing the fourth embodiment.

FIG. 5 is a side view of a conventional tapered roller.

FIG. 6 is a side view of a conventional cylindrical roller.

[Explanation of symbols]

 1 Tapered roller 2 Cylindrical roller 3 Large diameter side end surface 4 Rolling surface 5 Anti-carbon treatment layer 6 End surface 7 Rolling surface

[Procedure amendment]

[Submission date] December 28, 1995

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0005

[Correction method] Change

[Correction contents]

Further, most of the heat generated by the sliding of the end surface of the tapered roller 1 or the cylindrical roller 2 with the side surface of the flange enters the sliding surface by heat conduction. The rise in the surface temperature of the sliding portion due to this heat conduction changes depending on the material components. That is,
Considering the surface temperature rise θ due to a plane moving heat source with a circular uniform distribution on the surface of a semi-infinite body, letting the heat generation amount be Q, the moving speed V
Is large (L> 3), it is expressed by the following equation. θ = 0.254Q / (λ · r · L ^1/2 ) λ: Thermal conductivity r: Heat source radius L: V · r / (2κ) κ: Thermal diffusivity V: Heat source moving speed where λ, The value of κ changes depending on the carbon concentration in the steel and the like, and if the other material constituents are the same, the value increases as the carbon content decreases. Therefore, the lower the carbon concentration in the steel, the smaller the surface temperature rise. In the case of each roller 1 or 2 having a carburized layer or carbonitrided layer formed on the end surface, since the amount of carbon in the surface layer of the end surface of each roller 1, 2 is large, the end surface of each roller 1, 2 and the side surface of the collar are It is conceivable that the surface temperature rise during sliding will be large. If such a surface temperature rise is remarkable, it will cause seizure and the like. Therefore, it is not preferable that the surface temperature rise becomes large. The roller for a roller bearing of the present invention was invented in view of these circumstances.

Claims (1)

[Claims] 1. A surface heat treatment layer which is a carburized layer or a carbonitriding layer is provided on the rolling surface, and the surface heat treatment layer is not provided on at least the end face which comes into contact with the side surface of the collar formed on the bearing ring.
Alternatively, a roller bearing roller in which a surface heat treatment layer is not provided as much as the surface heat treatment layer provided on the rolling contact surface and the workability of the end face in terms of shape accuracy and surface roughness is improved.