JP2006077802A - Rolling sliding member and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling sliding member capable of reducing the frictional force on the rolling sliding surface and improving the friction resistance in both the fluid lubrication state and the boundary lubrication state, and a manufacturing method thereof.
SOLUTION: A plurality of independent fine concave portions 11 are formed on a rolling sliding surface with respect to a mating member, and a surface of a convex portion 12 existing between the concave portions 11 is substantially flattened so that the substantially flat surface is By forming the fixed lubricant film 13 on the surface, the concave portion 11 functions as an oil reservoir in the fluid lubrication state to improve the effect of forming the oil film, and in the boundary lubrication state, the solid on the surface of the substantially flat convex portion 12. The lubricant film 13 can reduce the friction force between the mating member and the wear resistance. By forming the recess 11 by shot peening and forming the solid lubricant film 13 by shot injection of solid lubricant particles, the processing cost can be kept low.
[Selection] Figure 4

Description

  The present invention relates to a rolling sliding member that makes rolling contact and / or sliding contact with a mating member and a method for manufacturing the same.

  In members that are in rolling contact with each other, such as the raceway surfaces of the inner and outer rings of roller bearings, or members that are in sliding contact with each other, and members that are in rolling contact and sliding contact with each other, such as in the raceway surfaces of thrust roller bearings By forming a large number of independent fine recesses on the surface that makes rolling contact and / or sliding contact with the mating member, each recess functions as an oil reservoir, and an oil film forming effect between the contact surfaces of each other It is known that the friction coefficient can be increased and the friction coefficient can be reduced and the wear resistance can be improved (for example, Patent Document 1).

In addition to the oil film forming effect described above, the contact surface pressure with respect to the mating member can be achieved by setting the area other than the concave portion, that is, the area of the convex portion to 70% or more of the entire surface on the surface where the concave portion is formed. It is also known that the wear can be reduced by reducing (see, for example, Patent Document 2).
JP-A-5-240254 JP 9-42293 A

  By the way, in the technique of forming a large number of independent fine recesses on the rolling contact surface or the sliding contact surface as described above, the frictional force is reduced to some extent as a result of the reduction of the true contact area due to the presence of the recesses under boundary lubrication. For example, in an automobile chain-type continuously variable transmission, for example, between an end piece of a pin connecting a link of a chain and a sheave surface of a pulley, or between an interpiece inserted into a hole of a link together with the pin and the pin The effect is not sufficient for rolling sliding surfaces under severe boundary lubrication, such as between rolling sliding surfaces.

  An object of the present invention is to provide a rolling sliding member capable of reducing the frictional force on the rolling sliding surface and improving the wear resistance in both the fluid lubrication state and the boundary lubrication state, and a manufacturing method thereof. .

  In order to solve the above problems, the rolling sliding member of the present invention is a member that is in rolling contact and / or sliding contact with the mating member, and is in rolling contact and / or sliding contact with the mating member. A large number of independent fine recesses are formed on the surface, the surface of the protrusions between the recesses is substantially flattened, and a solid lubricant film is formed on the surface of the substantially flat surface. (Characterized in claim 1).

  Moreover, the method for producing a rolling sliding member according to the present invention is a method for producing the rolling sliding member according to claim 1, wherein after forming the above-mentioned numerous fine recesses by shot peening on the base material surface, Characterized by shot injection of solid lubricant particles onto the surface (claim 2).

  Here, in the method for producing a rolling sliding member of the present invention, the shot peening process for forming the numerous fine recesses includes a first shot peening process using relatively large diameter particles, and a small diameter particle. The structure (Claim 3) which includes the 2nd shot peening process using this and performs a 2nd shot peening process after the 1st shot peening process can be employ | adopted suitably.

  The present invention is intended by forming a large number of independent concave portions on the rolling sliding surface, and substantially flattening the surface of the convex portions existing between them to form a solid lubricant film thereon. It is intended to achieve the purpose.

  That is, a large number of independent fine recesses formed on the rolling sliding surface function as an oil reservoir as in the conventional technique described above, and can improve the oil film forming effect under fluid lubrication. In addition, under boundary lubrication, the surface of the convex portion is substantially flattened, and the frictional force between the mating member is reduced by the solid lubricant film formed thereon, so that the wear resistance is improved. .

  In the method for manufacturing a rolling sliding member according to the present invention, a large number of fine recesses are formed by shot peening, and the solid lubricant film is also formed by shot injection of fixed lubricant particles. By adopting this method, it is possible to form the concave portion and the solid lubricant film substantially only by the shot process, and to keep the processing cost low.

  Then, as in the invention according to claim 3, the shot peening process for forming the recesses is performed by using the first shot peening process using relatively large-diameter particles and the subsequent relatively small-diameter particles. By providing the second shot peening process, the raised portion of the protrusion between the recesses formed in the first shot peening process is flattened by the second shot peening process, and the surface of the protrusion is substantially flat. The processing for the conversion can also be performed in the shot peening process, which can contribute to the reduction of the processing cost.

  According to the rolling sliding member of the present invention, a large number of minute concave portions independent from each other function as an oil reservoir, and in particular, the oil film forming effect on the rolling sliding surface can be improved in the fluid lubrication state, and the boundary lubrication state , The solid lubricant film formed on the substantially flat surface of the convex surface existing between the concave portions is interposed between the mating member and the frictional force is reduced, so that the wear resistance can be improved. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a partial cross-sectional view showing the configuration of the main part of an embodiment in which the present invention is applied to a chain-type continuously variable transmission. FIG. 2 is a schematic diagram of the vicinity of an engaging portion between the pulley 2 or 4 and the chain 5. FIG. FIG. 3 is a cross-sectional view of the main part in which the chain 5 is cut along a direction orthogonal to the pin 52.

  A loop-shaped chain 5 is wound around a drive pulley 2 attached to the input shaft 1 and a driven pulley 4 attached to the output shaft 3. The chain 5 has a structure in which a plurality of links 51 each having two through holes 51a and 51b are connected to each other by pins 52 and interpieces 53 inserted into the through holes 51a and 51b. .

  The drive pulley 2 and the driven pulley 4 are constituted by fixed pulley plates 2a and 4a and movable pulley plates 2b and 4b, respectively. The fixed pulley plates 2a and 4a are fixed to the input shaft 1 or the output shaft 3, respectively. In addition, the movable pulley plates 2b and 4b are mounted so as to be movable in the axial direction with respect to the input shaft 1 or the output shaft 3, respectively. The movable pulley plates 2b and 4b are moved in the axial direction of the input shaft 1 or the output shaft 3 by driving the hydraulic servo actuators 6 and 7 disposed on the input shaft 1 or the output shaft 3. Due to the movement of the movable pulley plates 2a and 4a, the groove widths of the drive pulley 2 and the driven pulley 4 change, whereby the winding position of the chain 5 around the pulleys 2 and 4 changes, and the rotational speed of the input shaft 1 is reduced. The gear is shifted in stages and transmitted to the output shaft 3.

  The pin 52 and the interpiece 53 that connect the links 51 of the chain 5 are in rolling contact and / or sliding contact with each other in the through holes 51a and 51b. That is, the pin 52 is fixed in the one through hole 51a, and the interpiece 53 is loosely fitted to be swingable. In the other through hole 51b, an interpiece 53 is fixed, and the pin 52 is loosely fitted to be swingable. The facing surface 52a of each pin 52 facing the interpiece 53 has a convex curved surface (for example, a cross-sectional shape corresponding to the involute curve), and the facing surface 53a of each interpiece 53 facing the pin 52 is a flat surface. When the chain 5 is bent, the loose member of the pin 52 and the interpiece 53 is oscillated and displaced while being in rolling contact and / or sliding contact with the counterpart member. Suppresses the occurrence of noise by suppressing the occurrence of dynamic motion. The above basic configuration is known, for example, in JP-A-8-312725.

  In this embodiment, the length of each interpiece 53 is slightly shorter than the length of each pin 52, and among the members constituting the chain 5, only the both end surfaces of each pin 52 are the drive pulley 2 and the driven. It plays a role of contacting the inner surface of the groove of the pulley 4 to transmit power.

  And both the end surfaces of each pin 52 and the opposing surface 52a with respect to the interpiece 53, and the opposing surface 53a with respect to the pin 52 of each interpiece 53 have a surface structure as shown in a schematic sectional view in FIG. . That is, a large number of minute concave portions 10 independent of each other are formed on these surfaces, and the surface of the convex portion 12 existing between the concave portions 11 is substantially flattened to be substantially flat. A solid lubricant layer 13 is formed. The size of each recess 11 is about several tens of μm, and the film thickness of the solid lubricant layer 13 is about 1 μm. In other words, as the material of the solid lubricant layer 13, a known material such as molybdenum disulfide can be preferably used.

  According to such a surface structure, in the fluid lubrication state between the contact surfaces of the both ends of each pin 52 and each of the pulleys 1 and 3 and between the respective facing surfaces 52a and 53a of each pin 52 and each interpiece 53. Each recessed part 11 functions as an oil sump, and the formation effect of an oil film improves. In the boundary lubrication state, the frictional force is reduced by the solid lubricant layer 13 formed on the surface of the convex portion 12, and the wear resistance is improved. As a result, the durability of these members is improved.

  According to experiments, when the untreated friction coefficient is 1, the friction coefficient is reduced to about 0.3 by simply forming a solid lubricant layer, whereas in the above embodiment of the present invention, the friction coefficient is reduced. The coefficient decreased to about 0.1 to 0.2.

Next, an example of a method for forming the above surface structure will be described.
First, the first shot peening is performed using steel particles having a particle diameter of about 150 to 200 μm with respect to the surface to be processed, and then the second shot is performed using steel particles having a particle diameter of about 50 to 100 μm. Apply peening. As a result, the bulge (edge or burr) generated on the surface of the concave portion formed by the first shot peening is removed by the second shot peening, and the surface of the convex portion 12 is substantially flattened and at the same time compressed densely. As a result of the generation of the stress layer, the fatigue life of each member can be improved.

  Next, the solid lubricant layer 13 is formed by shot-injecting particles of a fixed lubricant such as molybdenum disulfide having a particle diameter of 5 to 20 μm. When the solid lubricant particles are shot, a part of the particles shot and sprayed on the member surface is reflected or dropped from the member surface, and a part of the particles adheres mainly to the surface of the substantially flat convex portion 12. A solid lubricant layer 13 having a thickness of about 1 μm is formed. Although some solid lubricant layer may be formed in the recess 11 as well, there is no problem that the recess 11 is filled and no oil pool is lost in relation to the size of the recess 11.

  According to such a method, it is possible to form the concave portion 11 and the solid lubricant layer 13 only by changing the size and type of the particles to be shot-injected, and thus to obtain the surface structure described above. Cost can be kept low.

  In the method of the present invention, the formation of the concave portion 11 and the flattening of the surface of the convex portion 12 are performed in the first and second shot peening processes, and after the concave portion 11 is formed on the surface of the member by the first shot peening. The surface of the convex portion 12 may be substantially flattened by polishing the surface.

  Further, in the above embodiment, an example in which the present invention is applied to a pin or an interpiece of a chain type continuously variable transmission has been shown. However, the present invention is not limited to this, and for example, a slide bearing or a rolling bearing. Needless to say, the present invention can also be applied to a surface having a high slip rate such as an end face and a saddle face of a roller.

It is a fragmentary sectional view which shows the principal part structure of embodiment which applied this invention to the chain type continuously variable transmission. FIG. 2 is a schematic cross-sectional view in the vicinity of an engaging portion between a pulley 2 or 4 and a chain 5 in FIG. 1. FIG. 3 is a cross-sectional view of a main part of the chain 5 in FIGS. 1 and 2 cut along a direction orthogonal to a pin 52. It is typical sectional drawing which shows the surface structure of the both ends of the pin 52 and the interpiece 53 in embodiment of this invention, and opposing surface 52a, 53a.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Input shaft 2 Drive pulley 3 Output shaft 4 Driven pulley 5 Chain 51 Link 51a, 51b Through hole 52 Pin 53 Interpiece 6, 7 Hydraulic servo actuator 11 Concave part 12 Convex part 13 Solid lubricant layer

Claims (3)

A member that makes rolling contact and / or sliding contact with a mating member,
A number of independent fine recesses are formed on the surface that makes rolling contact and / or sliding contact with the mating member, and the surfaces of the protrusions existing between the recesses are substantially flattened, and A rolling sliding member characterized in that a solid lubricant film is formed on the surface of the substantially flat surface. A method for producing the rolling sliding member according to claim 1,
A method for producing a rolling sliding member, comprising: forming a large number of fine recesses on a surface of a base material by shot peening, and then spraying solid lubricant particles onto the surface.   The shot peening process for forming a large number of fine recesses includes a first shot peening process using relatively large diameter particles and a second shot peening process using relatively small particles, and the first shot peening process. The method of manufacturing a rolling sliding member according to claim 2, wherein a second shot peening step is performed after the step.

Images