JP2008019916A - Thrust needle roller bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thrust needle roller bearing that can be prevented from getting in or seizing even when used for high-speed rotation. <P>SOLUTION: The thrust needle roller bearing 10 includes a plurality of needle rollers 11 and a cage 12 for retaining the needle rollers 11 in such a way as to allow the rollers to roll freely. The cage 12 has a surface coated with a film 16 of manganese phosphate after being subjected to soft nitriding. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a thrust needle roller bearing.

  Conventionally, thrust needle roller bearings are used in automobiles and industrial machines, for example, compressors and torque converters for automobile air conditioners, and rotating parts of automobile transmissions. In recent years, automatic transmissions have been multistaged, and thrust needle roller bearings applied thereto are required to have high-speed resistance.

Conventionally, in order to improve the wear resistance and surface hardness of a cage, a technique of soft-nitriding a cold-rolled steel plate (SPC material) that is a cage material has been used (for example, see Patent Document 1). . As shown in FIG. 5 (a), the cage subjected to soft nitriding described in Patent Document 1 is an iron nitride compound layer having excellent wear resistance having a thickness of about 10 μm on the outermost surface of the base layer 14. 15 is generated.
JP 2006-17244 A

  By the way, in the cage subjected to soft nitriding treatment, as shown in FIG. 5B, a porous 15a is formed on the surface of the compound layer 15, and the wear resistance can be exhibited by the effect of the oil reservoir. When the thrust needle roller bearing is rotated at a high speed, high centrifugal force and peripheral speed are generated in the roller, and the surface of the compound layer 15 falls off at the outer diameter side end surface of the cage pocket in contact with the roller end surface. However, concave abnormal wear (grinding) may occur. If this wear progresses, it may cause an increase in rotational torque, an increase in heat generation, and seizure.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thrust needle roller bearing capable of preventing scooping and seizure even when used at high speed rotation.

The above object of the present invention can be achieved by the following constitution.
(1) A thrust needle roller bearing comprising a plurality of needle rollers, and a cage that rotatably accommodates the needle rollers,
A thrust needle roller bearing, wherein the cage has a surface on which a manganese phosphate coating is applied after soft nitriding.

  According to the thrust needle roller bearing of the present invention, the cage is manufactured by applying the manganese phosphate coating after the soft nitriding treatment, so that high seizure resistance and lubricity are maintained, and high speed rotation is achieved. Even when used, it can prevent grime and burn-in.

  Hereinafter, a thrust needle roller bearing according to an embodiment of the present invention will be described in detail with reference to the drawings.

  As shown in FIG. 1, the thrust needle roller bearing 10 includes a plurality of needle rollers 11 and a cage 12 that accommodates the needle rollers 11 in a rollable manner. Arranged between. The cage 12 is formed by bending an annular plate made of cold-rolled steel plate (SPC material) to have a substantially W-shaped cross section, and a plurality of cages 12 are used to hold the needle rollers 11 at predetermined intervals in the circumferential direction. Pocket 13.

  As shown in FIG. 2, the surface of the cage 12 is subjected to soft nitriding on the surface of the mother layer 14 to produce an iron nitride compound layer 15 having a thickness of about 10 μm or less. Similar to the above, innumerable holes 15a called porous exist on the outermost surface. Then, the manganese phosphate coating 16 enters the porous 15a as shown in FIG. 2B by applying the manganese phosphate coating after the soft nitriding treatment. The manganese phosphate coating 16 is formed with a film thickness of about 1 to 10 μm by chemical conversion treatment with a chemical, and has a high effect on seizure resistance and self-lubricity.

  Thus, when the manganese phosphate coating 16 enters the porous 15a, as shown in FIG. 4, even if the surface is worn, the lubrication is not lost, and high seizure resistance and lubricity are maintained. Even in this case, it is possible to prevent scooping in the outer diameter side end surface 12a of the pocket 13 and to prevent an increase in rotational torque and seizure.

  As described above, according to the thrust needle roller bearing 10 of the present embodiment, the cage 12 has a surface on which the manganese phosphate coating 16 is applied after the soft nitriding treatment, so that the surface is worn. Even when used at a high speed rotation, it is possible to prevent scooping and seizure.

In addition, this invention is not limited to the said embodiment, In the range which does not deviate from the summary of this invention, it can change suitably.
In this embodiment, the cage is formed by bending one plate material. However, as shown in FIG. 4, two bent plate materials may be superposed. Both are manufactured by the same surface treatment as described above. Further, the thrust needle roller bearing is not limited to that of the above-described embodiment, and may be one that is radially arranged in a double row, for example.

  Here, a high-speed test was performed under the following conditions using a thrust needle roller bearing having an inner diameter of 50 mm, an outer diameter of 70 mm, a plate thickness of 0.5 mm, and a roller diameter of 2.5 mm.

  The test bearing 1 is subjected to soft nitriding treatment on the surface of the cage, and then a manganese phosphate coating is applied. On the other hand, the test bearing 2 is obtained by performing only soft nitriding on the surface of the cage. The specifications other than the surface treatment were the same. The test results are shown in Table 1.

・ High-speed test condition Rotation speed: 12000rpm
Load: No load Lubricant: ATF (Automatic Transmission Fluid)
Test time: 50Hr

  As a result, it can be confirmed that the wear resistance can be improved by applying the soft nitriding treatment and the manganese phosphate coating on the surface of the cage.

It is sectional drawing for demonstrating the thrust needle roller bearing which is one Embodiment of this invention. (A) is sectional drawing which shows the structure of the surface of the holder | retainer of FIG. 1, (b) is the II section expanded sectional view of (a). It is an expanded sectional view which shows the state with which the surface of the holder | retainer of FIG. 1 was worn out. It is sectional drawing which shows the modification of the thrust needle roller bearing of this invention. (A) is sectional drawing which shows the structure of the surface after soft nitriding processing was given to the surface of the cage | basket, (b) is the V section enlarged sectional view of (a).

Explanation of symbols

10 Thrust Needle Roller Bearing 11 Needle Roller 12 Cage 13 Pocket 14 Base Layer 15 Compound Layer 16 Manganese Phosphate Coating

Claims (1)

A thrust needle roller bearing comprising a plurality of needle rollers and a cage that rotatably accommodates the needle rollers,
A thrust needle roller bearing, wherein the cage has a surface on which a manganese phosphate coating is applied after soft nitriding.

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