JP2017150522A - Bearing unit for railway vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To take effective abrasion countermeasure on a contact surface between an inner ring and a rear lid at low cost, in a bearing unit for a railway vehicle.SOLUTION: A bearing unit for a railway vehicle includes a rolling bearing externally mounted on a rotational shaft, and a rear lid externally fitted and fixed to the rotational shaft and configured to contact with an inner ring of the rolling bearing to position the inner ring to the rotational shaft. On at least one of a contact surface of the inner ring with the rear lid and a contact surface of the rear lid with the inner ring, a MoSfilm is formed through a phosphate film.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a railway vehicle bearing unit, and more particularly, to a technique for preventing wear of a contact surface between a rear lid provided for positioning an inner ring of a rolling bearing and the inner ring.

  In a rolling bearing that supports a rotating shaft of a railway vehicle, as shown in FIG. 1, an inner ring 10 is fitted and fixed to the rotating shaft 1, and a rear lid 20 is provided to restrict the position of the inner ring 10. . The rear lid 20 has an end on the wheel side (right side in the figure) engaged with the enlarged diameter step portion 1 a of the rotating shaft 1 and the other end surface in contact with the inner ring 10. Therefore, the contact surface 10a (hereinafter also referred to as “inner ring contact surface”) with the rear lid 20 of the inner ring 10 and the contact surface 20a with the inner ring 10 of the rear cover 20 (hereinafter also referred to as “rear cover contact surface”). Will wear fretting. In addition, wear powder is generated and enters the inside of the bearing, causing problems such as deterioration of grease and damage to the raceway surface.

  Therefore, a lubricant film for preventing wear is formed on the inner ring contact surface 10a and the rear lid contact surface 20a. For example, in Patent Document 1, a DLC (diamond-like carbon) film is formed on at least one of the inner ring contact surface 10a and the rear cover contact surface 20a to reduce the coefficient of friction, thereby suppressing fretting wear.

JP 2003-254340 A

  However, the DLC film is expensive, and an object of the present invention is to provide an effective wear countermeasure on the inner ring, the rear cover, and the contact surface at a lower cost.

In order to solve the above-described problems, the present invention provides a rolling bearing that is externally mounted on a rotating shaft, and is fitted and fixed to the rotating shaft, and abuts against an inner ring of the rolling bearing to the rotating shaft. In a railway vehicle bearing unit including a rear lid for positioning an inner ring, a phosphate coating is interposed on at least one of a contact surface of the inner ring with the rear cover and a contact surface of the rear cover with the inner ring. The present invention provides a railway vehicle bearing unit characterized in that a MoS ₂ coating is formed.

  According to the present invention, in the railway vehicle bearing unit, a lubricating coating excellent in the effect of preventing wear can be formed at a lower cost on at least one of the contact surface of the inner ring and the contact surface of the rear lid.

It is principal part sectional drawing which shows an inner ring | wheel and a rear cover in a railway wheel bearing unit.

  Hereinafter, the present invention will be described in detail with reference to the drawings.

In the present invention, in the railway wheel bearing unit as shown in FIG. 1, the MoS ₂ coating is provided on at least one of the inner ring contact surface 10a and the rear cover contact surface 20a, preferably on both through a phosphate coating. Form. In addition to the rust prevention effect, the phosphate coating serves as an underlayer for the MoS ₂ coating formed thereon, and firmly bonds the MoS ₂ coating to the inner ring contact surface 10a and the rear lid contact surface 20a. Moreover, since a phosphate film has a rust prevention effect, it is preferable to form in the whole surface of the back cover 20. As shown in FIG. On the other hand, MoS ₂ is a solid lubricant and effectively suppresses fretting wear between the both contact surfaces 10a and 20a.

  As a method for forming the phosphate coating, chemical conversion treatment is preferable. The chemical conversion treatment is a general method for forming a phosphate film on the metal surface, and is simple and can reduce the manufacturing cost. Specifically, a phosphate solution containing a phosphate such as iron phosphate, zinc phosphate, or manganese phosphate is applied to the inner ring contact surface 10a or the rear cover contact surface 20a and heated. A coating is produced. Instead of coating, the inner ring contact surface 10a and the rear cover contact surface 20a may be immersed in a phosphate solution. In particular, when a phosphate film is formed on the entire surface of the rear lid 20, the dipping method is simple.

Next, a MoS ₂ solution containing MoO ₂ powder and an appropriate binder is applied to the abutting surface 10a of the inner ring and the abutting surface 20a of the rear lid on which the phosphate coating is formed, and the binder is cured to form a coating. Form. Instead of coating, the contact surface 10a of the inner ring and the contact surface 20a of the rear lid may be immersed in the MoS ₂ solution. During film formation, a part of the MoS ₂ powder enters the recesses of the phosphate coating, and the adhesion of the MoS ₂ coating to the phosphate coating is enhanced.

  Thus, both coatings can be formed by a simple method such as coating or dipping, and the manufacturing cost can be kept low.

  If both coatings are too thin, the respective effects will not be exhibited, or the effects will disappear at an early stage, and if they are too thick, the coatings may be cracked and peeled off. Therefore, it is preferable that the total film thickness of these films is 5 to 50 μm.

Further, the MoS ₂ coating, in order to enhance the lubricating performance, it is possible to add other solid lubricants such as, the addition of other solid lubricant MoS ₂ solution.

1 Rotating shaft 10 Inner ring 10a Inner ring contact surface 20 Rear cover 20a Rear cover contact surface

Claims (1)

A railway vehicle comprising: a rolling bearing that is externally mounted on a rotating shaft; and a rear lid that is fitted and fixed to the rotating shaft and that contacts the inner ring of the rolling bearing and positions the inner ring with respect to the rotating shaft. For bearing units,
A railway vehicle characterized in that a MoS ₂ coating is formed on at least one of a contact surface of the inner ring with the rear cover and a contact surface of the rear cover with the inner ring through a phosphate coating. Bearing unit.

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