JP2017150520A - Abrasion preventing structure of bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an abrasion preventing structure of a bearing capable of preventing abrasion of the bearing by substantially uniformly bringing the bearing and a contact member into contact with each other by simple processing.SOLUTION: A flexible portion 13 is a part for deflecting a rear cover 9 so that a contact face 3g at a bearing 3 side and a contact face 9a at a rear cover 9 side are substantially uniformly brought into contact with each other when pressing force is applied in a direction of bringing the bearing 3 and the rear cover 9 into close contact with each other. The flexible portion 13 deflects the rear cover 9 so that the contact face 3g at the bearing 3 side and the contact face 9a at the rear cover 9 side are substantially uniformly brought into contact with each other by partially lowering bending rigidity of the rear cover 9 to make contact face pressures therebetween substantially uniform. The flexible portion 13 includes a plurality of groove portions 14a formed in a circumferential direction of an outer peripheral face 9c of the rear cover 9 at prescribed intervals in a longitudinal direction (a direction in parallel with a center axis of an axle 1) of the rear cover 9.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a bearing wear preventing structure for preventing wear generated on contact surfaces when a bearing and a contact member contacting the bearing contact non-uniformly.

  A conventional axle bearing device (hereinafter referred to as “Prior Art 1”) has a contact surface between the end face of the flange portion of the bearing and the rear cover in a range not less than the inner diameter of the inner ring of the bearing and not more than 1.2 times the inner diameter of the inner ring. An annular groove is formed outside the contact surface (see, for example, Patent Document 1). In this prior art 1, fretting wear powder generated by wear on the contact surface between the flange end face of the inner ring of the bearing and the rear cover is confined in the annular groove.

  In a conventional railway vehicle bearing device (hereinafter referred to as Prior Art 2), an annular spacer is fitted between the inner ring of the bearing and the rear lid so that the inner ring of the bearing and the rear lid are not in direct contact ( For example, see Patent Document 2). In this prior art 2, an annular spacer is inserted between the inner ring and the rear lid of the bearing, thereby suppressing the occurrence of fretting wear powder due to contact between the inner ring and the rear lid of the bearing.

  A conventional railcar bearing unit (hereinafter, referred to as “prior art 3”) changes the shape of the contact surface on the rear lid side so that the inner ring of the bearing and the rear lid are in uniform contact (for example, Patent Document 3). reference). In this prior art 3, the contact portion on the rear lid side is formed in a convex curved surface so that the contact portion between the inner ring of the bearing and the rear lid does not become a flat surface, and the contact at the contact portion between the inner ring of the bearing and the rear lid is performed. The uneven surface pressure is eliminated.

JP 2001-254735 A

JP 2004-332905 A

JP 2011-112122 A

  In Prior Art 1, an annular groove is formed on the outer side of the contact surface between the flange end face of the bearing and the rear lid. For this reason, in the prior art 1, when an annular groove is formed at a position where the contact surface pressure of the contact surface between the flange end face of the bearing and the rear lid is low, fretting wear occurs from a position where the contact surface pressure of the contact surface is high. There is a problem that the powder cannot be confined in the annular groove and the occurrence of fretting wear itself cannot be prevented. In the prior art 2, an annular spacer, which is a separate member, is fitted between the inner ring of the bearing and the rear lid. For this reason, in the prior art 2, there is a problem in that the number of components constituting the railway vehicle bearing device increases, which takes time for assembly and increases the manufacturing cost. Further, these prior arts 1 and 2 aim to prevent fretting wear powder from entering the inside of the bearing, and there is a problem that fretting wear itself cannot be prevented. In the prior art 3, it is necessary to form the contact portion on the rear lid side in a cross-sectional curve such as a polynomial or an exponential function, and there is a problem that it takes time to design the cross-sectional curve and to process the rear lid.

  An object of the present invention is to provide a bearing wear prevention structure capable of preventing the bearing from being worn by making the bearing and the contact member substantially uniformly contacted by simple processing.

The present invention solves the above-mentioned problems by the solving means described below.
In addition, although the code | symbol corresponding to embodiment of this invention is attached | subjected and demonstrated, it is not limited to this embodiment.
As shown in FIGS. 2 to 9 and 11, the invention of claim 1 is configured such that when the bearing (3) and the contact member (9) in contact with the bearing contact non-uniformly, these contact surfaces ( 3g, 9a) is a bearing wear prevention structure for preventing wear generated in the bearing, and when a pressing force is applied in a direction in which the bearing and the contact member are in close contact with each other, the bearing side contact surface (3g) A bearing wear prevention structure (12) comprising a flexible portion (13) for bending the contact member so that the contact surface (9a) on the contact member side and the contact surface (9a) are in contact with each other substantially uniformly. .

  A second aspect of the present invention is the bearing wear preventing structure according to the first aspect, wherein the flexible portion is a thin portion of the contact member.

  According to a third aspect of the present invention, in the bearing wear prevention structure according to the first or second aspect, as shown in FIGS. 2 to 6 and 11, the flexible portion is a length direction of the contact member. And a plurality of grooves (14a) formed in the circumferential direction of the outer peripheral surface (9c) and / or the inner peripheral surface (9b) of the contact member at a predetermined interval. Wear prevention structure.

  According to a fourth aspect of the present invention, in the bearing wear prevention structure according to the first or second aspect, as shown in FIGS. 7 to 9, the flexible portion includes the outer peripheral surface (9 c) and the contact member. A bearing wear prevention structure comprising a groove (14b) formed in the circumferential direction of the inner peripheral surface (9b).

  According to a fifth aspect of the present invention, in the structure for preventing wear of a bearing according to the first or second aspect, as shown in FIG. 11, the flexible portion has a predetermined interval in the length direction of the contact member. And a plurality of groove portions (14b) formed in the circumferential direction of the outer peripheral surface (9c) of the contact member, and the plurality of groove portions on the flexible portion side include a plurality of grooves on the fixed body (15) side. This is a bearing wear prevention structure characterized in that a labyrinth seal portion (16) for sealing the gap is formed by facing the groove portion (15a) with a gap therebetween.

  According to a sixth aspect of the present invention, in the bearing wear prevention structure according to any one of the first to fifth aspects, as shown in FIGS. 2 to 9 and FIG. The bearing wear prevention structure is characterized in that it is formed on a rear lid (9) or an oil drainer (8) in contact with an inner ring of the bearing.

  According to the present invention, the bearing and the contact member can be brought into substantially uniform contact with each other by simple processing to prevent the bearing from being worn.

1 is a longitudinal sectional view schematically showing a bearing assembly including a bearing wear preventing structure according to a first embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS It is an external view of a back cover provided with the abrasion-proof structure of the bearing which concerns on 1st Embodiment of this invention, (A) is a top view, (B) is the state cut | disconnected by the II-IIB line | wire of (A). It is sectional drawing shown. It is a longitudinal cross-sectional view which abbreviate | omits and shows a part of rear cover provided with the abrasion-proof structure of the bearing which concerns on 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows typically the state in which the axle in which the rear cover provided with the wear prevention structure of the bearing which concerns on 1st Embodiment of this invention is press-fitted is bent, (A) is a case where a wear prevention structure exists (B) is a longitudinal sectional view when no wear prevention structure is present. BRIEF DESCRIPTION OF THE DRAWINGS It is a longitudinal cross-sectional view which shows typically the state which press-fitted the back cover provided with the abrasion prevention structure of the bearing which concerns on 1st Embodiment of this invention to the anti-shaft end side rather than a predetermined position, (A) is a wear prevention structure. It is a longitudinal cross-sectional view when it exists, (B) is a longitudinal cross-sectional view when a wear prevention structure does not exist. It is a longitudinal cross-sectional view which abbreviate | omits and shows a part of rear cover provided with the abrasion-proof structure of the bearing which concerns on 2nd Embodiment of this invention, (A) is a case where a flexible part is provided in the internal peripheral surface of a rear cover. It is a longitudinal cross-sectional view, (B) is a longitudinal cross-sectional view when a flexible part is provided on the outer peripheral surface and the inner peripheral surface of the rear lid. It is an external view of a back cover provided with the abrasion-proof structure of the bearing which concerns on 3rd Embodiment of this invention, (A) is a top view, (B) is the state cut | disconnected by the VII-VIIB line of (A). It is sectional drawing shown. It is a longitudinal cross-sectional view which abbreviate | omits and shows a part of rear cover provided with the abrasion-proof structure of the bearing which concerns on 3rd Embodiment of this invention. It is a longitudinal cross-sectional view which abbreviate | omits and shows a part of rear cover provided with the abrasion-proof structure of the bearing which concerns on 4th Embodiment of this invention, (A) is a case where a flexible part is provided in the inner peripheral surface of a rear cover. It is a longitudinal cross-sectional view, (B) is a longitudinal cross-sectional view when a flexible part is provided on the outer peripheral surface and the inner peripheral surface of the rear lid. It is a longitudinal cross-sectional view which shows roughly the bearing assembly provided with the abrasion-proof structure of the bearing which concerns on 5th Embodiment of this invention. It is a longitudinal cross-sectional view which abbreviate | omits and shows a part of labyrinth seal part of a bearing assembly provided with the abrasion-proof structure of the bearing which concerns on 5th Embodiment of this invention. It is a contour figure which shows the result by the finite element analysis of the rear cover which concerns on Example 1 of this invention. It is a contour figure which shows the result by the finite element analysis of the rear cover which concerns on Example 2 of this invention. It is a contour figure which shows the result by the finite element analysis of the rear cover which concerns on a prior art example. It is a graph which shows the pressure distribution of the contact surface of the rear cover which concerns on the Example and comparative example of this invention.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings.
An axle 1 shown in FIG. 1 is a member that rotates about a central axis O. The axle 1 has, for example, a pair of left and right wheels of a railway vehicle that are press-fitted and attached to both ends of the axle 1 and rotates together with the wheels. As shown in FIG. 1, the axle 1 includes a journal portion 1a, a dust guard seat 1b, a wheel seat 1c, a medium diameter portion 1d, a groove portion 1e, and the like. The journal part 1a is a part supported by the bearing 3, and supports the vehicle body load of the railway vehicle. In the journal portion 1a, the inner peripheral surface of the inner ring 3d of the bearing 3 is fitted into the outer peripheral surface of the journal portion 1a. The dust cover 1b is a portion to which the rear lid 9 is attached. The dust guard 1b is formed on the opposite side of the axle 1 (on the side opposite to the end of the axle 1 (wheel seat 1c side shown in FIG. 1)), and on the outer circumferential surface of the dust guard 1b. The inner peripheral surface of the rear lid 9 is press-fitted and fitted. The wheel seat 1c is a portion where wheels are mounted. The wheel seat 1 c is press-fitted and fitted with the inner peripheral surface of the boss hole of the wheel, and fixes the wheel at a predetermined position of the axle 1. The medium diameter portion 1d is a step portion formed between the journal portion 1a and the wheel seat 1c. The groove 1 e is a recess formed at a predetermined depth and length at the end of the axle 1 in parallel with the central axis O of the axle 1.

  The bearing assembly 2 is a member in which main components of the bearing 3 are assembled. The bearing assembly 2 is held at a predetermined position of the bogie frame of the bogie while being accommodated in, for example, an axle box of a railway vehicle. As shown in FIG. 1, the bearing assembly 2 includes a bearing 3, a shaft end nut 4, a small lid 5, a locking bolt 6, a sealing structure 7, and the like. The bearing assembly 2 is sealed with a lubricant such as grease filled therein, for example.

  The bearing 3 is a member that rotatably supports the axle 1. A bearing 3 shown in FIG. 1 is a rolling bearing that rotatably supports both end portions of an axle 1. The bearing 3 includes a rolling element 3 a that rolls between the outer ring 3 c and the inner ring 3 d, a cage 3 b that holds the rolling element 3 a at equal intervals, an outer ring 3 c that is fixed to the axle box side, and the axle 1. The inner ring 3d that rotates and the flange 3e that is formed integrally with the outer end of the inner ring 3d and receives an axial load, and the spacer 3f that is inserted between the left and right inner rings 3d to adjust the clearance and the pressurization. And a flat contact surface (end surface) 3g that contacts the contact surface 9a on the rear lid 9 side. A bearing 3 shown in FIG. 1 is a double-row tapered roller bearing in which two rows of tapered rollers are arranged as rolling elements 3 a, and is fitted to the outer peripheral surface of the journal portion 1 a of the axle 1. The bearing 3 shown in FIG. 1 is, for example, a double-row tapered roller bearing that receives an axial axial load with the flange of the inner ring 3d.

  The shaft end nut 4 is a member that positions and fixes the bearing 3 at a predetermined position by sandwiching the oil drain 8 and the bearing 3 with the rear lid 9. The shaft end nut 4 is a member having an annular appearance, and has a female screw portion that engages with a male screw portion formed at the end portion of the axle 1 on the inner peripheral surface. The shaft end nut 4 is detachably attached to the end portion of the axle 1. It is installed. The shaft end nut 4 is applied to the bearing 3, the oil drain 8, and the rear lid 9 by being fastened to the male thread portion of the axle 1. The shaft end nut 4 causes the contact surface 3g of the inner ring 3d of the bearing 3 and the contact surface 9a of the rear lid 9 to be in close contact with each other by applying a pressing force (pressing force) in the length direction of the axle 1. The contact surface 3g of the inner ring 3d and the contact surface 8a of the oil drain 8 are brought into close contact with each other.

  The small lid 5 is a member fitted to the axle 1. The small lid 5 is a metal member having an annular appearance. The small lid 5 includes a protruding portion 5 a that protrudes from the inner peripheral portion and engages with the groove portion 1 e of the axle 1. The small lid 5 rotates integrally with the axle 1 by fitting the protrusion 5 a into the groove 1 e of the axle 1.

  The locking bolt 6 is a member that prevents the shaft end nut 4 from loosening. The locking bolt 6 is provided with a male threaded portion engaged with a female threaded portion formed at a predetermined depth on the end face of the shaft end nut 4 at the tip. The locking bolt 6 is detachably attached to the shaft end nut 4 through the through hole of the small lid 5, and the shaft 5 in a state where the projection 5 a of the small lid 5 is fitted to the groove 1 e of the axle 1. The end nut 4 and the small lid 5 are integrated to prevent the shaft end nut 4 from rotating.

  The sealing structure 7 is a structure for sealing the bearing assembly 2. The sealing structure 7 seals the inside of the bearing assembly 2 in a state where the bearing 3 is accommodated in the bearing assembly 2, prevents the lubricant in the bearing 3 from leaking to the outside, Prevent foreign material from entering the door. The sealing structure 7 includes an oil drainer (slinger (flinger)) 8, a rear lid 9, seal cases 10A and 10B, oil seals 11A and 11B, and the like. The sealing structure 7 prevents the lubricant from leaking from the inside of the bearing 3 to the outside by combining components such as the oil drain 8, the rear lid 9, the seal cases 10A and 10B, and the oil seals 11A and 11B. At the same time, foreign matter is prevented from entering the bearing 3 from the outside.

  The oil drainer 8 is a member that prevents the lubricant from leaking from the inside of the bearing 3 toward the shaft end side. The oil drainer 8 is a metal member whose appearance is cylindrical. The oil drainer 8 is press-fitted into the outer peripheral surface of the journal portion 1a of the axle 1 so that the inner peripheral surface of the oil drainer 8 is rotatably fitted integrally with the axle 1, and the shaft end nut 4 and bearing 3 Between the inner ring 3d and the inner ring 3d. The oil drainer 8 includes a contact surface 8a, an inner peripheral surface (inner diameter surface) 8b, an outer peripheral surface (outer diameter surface) 8c, and the like.

  The contact surface 8a is a portion that contacts the contact surface 3g on the bearing 3 side. The contact surface 8a is formed flat along the circumferential direction of the end surface of the oil drainer 8 like the contact surface 3g. The inner peripheral surface 8 b is a surface on the side that fits with the axle 1. The inner peripheral surface 8 b is a fitting surface that fits with the outer peripheral surface of the journal portion 1 a of the axle 1. The outer peripheral surface 8 c is a surface on the opposite side to the side fitted with the axle 1. The outer peripheral surface 8c includes a facing surface 8d that faces the inner peripheral surface of the end portion of the seal case 10A in a non-contact manner, and a sliding surface 8e on which the tip portion (lip) of the oil seal 11A slides.

  The rear lid 9 shown in FIGS. 1 and 2 is a member that prevents the lubricant from leaking outside from the inside of the bearing 3 toward the opposite shaft end side. The rear cover 9 is a metal member having a cylindrical appearance. The rear lid 9 is a rotating body that the inner peripheral surface of the rear lid 9 is press-fitted into the outer peripheral surface of the dust guard seat 1 b of the axle 1 and is rotatably fitted integrally with the axle 1. As shown in FIGS. 1 and 3, when the rear lid 9 is press-fitted from the shaft end side of the axle 1, the stepped portion between the fitting surface 9 d and the fitting surface 9 e is prevented from being separated from the axle 1. It is positioned at a predetermined position of the axle 1 by being caught by a step portion between the seat 1b and the middle diameter portion 1d. As shown in FIG. 1, the rear lid 9 positions the bearing 3 at a predetermined position of the axle 1 by sandwiching the inner ring 3 d of the bearing 3 between the rear cover 9 and the oil drainer 8, and applies pressure (pressing force) to the bearing 3. ). As shown in FIGS. 1 and 3, the rear lid 9 is a contact member that contacts the bearing 3, and is in contact with the inner ring 3 d of the bearing 3. The rear lid 9 includes a contact surface 9a, an inner peripheral surface (inner diameter surface) 9b, an outer peripheral surface (outer diameter surface) 9c, a wear prevention structure 12, and the like, as shown in FIGS.

  The contact surface 9a shown in FIGS. 1 to 3 is a portion that contacts the contact surface 3g on the bearing 3 side. The contact surface 9a is formed flat along the circumferential direction of the end surface of the rear lid 9, similarly to the contact surface 3g. The inner peripheral surface 9 b is a surface on the side that fits with the axle 1. The inner peripheral surface 9b includes a fitting surface 9d that fits with the inclined surface on the shaft end side of the dust guard 1b, a fitting surface 9e that fits with the circumferential surface on the shaft end side of the medium diameter portion 1d, There is a non-fitting surface 9 f that forms a gap between the shaft 1 and the inclined surface on the shaft end side of the dust-proof seat 1 b of the axle 1 and does not fit with the axle 1. The outer peripheral surface 9 c is a surface on the opposite side to the side fitted with the axle 1. The outer peripheral surface 9c slides on the opposing surface 9g facing the inner peripheral surface of the end portion of the seal case 10B shown in FIGS. 1 and 3 in a non-contact manner, and the lip (tip portion) 11a of the oil seal 11B shown in FIG. And a non-sliding surface 9i on which the seal case 10B and the oil seal 11B shown in FIGS. 1 and 3 do not slide.

  A seal case 10A shown in FIG. 1 is a member that prevents the lubricant inside the bearing 3 from leaking outside between the bearing 3 and the oil drain 8 toward the shaft end side. The seal case 10 </ b> B is a member that prevents the lubricant inside the bearing 3 from leaking outside between the bearing 3 and the rear lid 9 toward the opposite shaft end side. The seal cases 10A and 10B are thin metal members that are cylindrical in appearance. The seal case 10 </ b> A is mounted between the outer ring 3 c of the bearing 3 and the oil drain 8. In the seal case 10A, the outer peripheral surface of one end of the seal case 10A is in close contact with the inner peripheral surface of the outer ring 3c, and the inner peripheral surface of the other end of the seal case 10A is in contact with the opposing surface 8d of the oil drainer 8. Opposite with a gap. The seal case 10 </ b> B is attached between the outer ring 3 c of the bearing 3 and the rear lid 9. In the seal case 10B, the outer peripheral surface of one end of the seal case 10B is in close contact with the inner peripheral surface of the outer ring 3c, and the inner peripheral surface of the other end of the seal case 10B is in contact with the opposing surface 9g of the rear lid 9. Opposite with a gap.

  The oil seal 11A is a member that seals between the oil drain 8 and the seal case 10A, and the oil seal 11B is a member that seals between the rear lid 9 and the seal case 10B. The oil seal 11A is sandwiched between the outer peripheral surface 8c of the oil drain 8 and the inner peripheral surface of the seal case 10A, and the oil seal 11B is formed between the outer peripheral surface 9c of the rear cover 9 and the inner peripheral surface of the seal case 10B. It is sandwiched between them. As shown in FIG. 3, the oil seal 11B includes a lip 11a that slides with the sliding surface 9h of the rear lid 9, and the oil seal 11A also includes a lip 11a that slides with the sliding surface 8e of the oil drain 8. It has a lip with the same structure. The oil seals 11 </ b> A and 11 </ b> B prevent the lubricant from leaking from the inside of the bearing assembly 2 to the outside and prevent foreign matter from entering the inside from the outside of the bearing assembly 2.

  The wear prevention structure 12 shown in FIGS. 1 to 3 is a structure that prevents wear generated on the contact surfaces 3g and 9a when the bearing 3 and the rear lid 9 that comes into contact with the bearing 3 come in non-uniform contact. It is. As shown in FIG. 4 (A), for example, the wear preventing structure 12 is bent by the axle 1 during traveling of the vehicle, or when the bearing is press-fitted as shown in FIG. 5 (A), the opposite end side of the rear lid 9 is deformed. In other words, when the contact surface 3g on the bearing 3 side and the contact surface 9a on the rear lid 9 side are in a biased contact, the rear lid 9 so that the contact surface 3g and the contact surface 9a are in contact with each other substantially uniformly. Bend. The wear prevention structure 12 includes a flexible portion 13 shown in FIGS. 2B and 3.

  The flexible portion 13 shown in FIG. 2B and FIG. 3 has a contact surface 3g on the bearing 3 side and a rear lid 9 side when a pressing force is applied in a direction in which the bearing 3 and the rear lid 9 are in close contact with each other. This is a portion that bends the rear lid 9 so that the contact surface 9a comes into contact with the contact surface 9a substantially uniformly. The flexible portion 13 is a thin portion of the rear lid 9 in which the thickness of the rear lid 9 is partially reduced, and is formed on the rear lid 9 in contact with the inner ring 3 d of the bearing 3. The flexible portion 13 is formed closer to the contact surface 9a of the rear lid 9 so that the contact surface 9a side of the rear lid 9 is bent and the rear lid 9 is elastically deformed. The flexible portion 13 partially lowers the bending rigidity of the rear lid 9, so that the contact surface 3g on the bearing 3 side and the contact surface 9a on the rear lid 9 side shown in FIGS. The rear lid 9 is bent so as to make the contact surface pressure between them substantially uniform. As shown in FIGS. 2B and 3, the flexible portion 13 is arranged at a predetermined interval in the length direction of the rear lid 9 (direction parallel to the central axis O of the axle 1). Are provided with a plurality of grooves 14a formed in the circumferential direction of the outer peripheral surface 9c.

  The groove 14a shown in FIG. 2B and FIG. 3 is formed in a straight line with a predetermined depth on the outer peripheral surface 9c of the rear lid 9 so as to be orthogonal to the central axis O of the rear lid 9. The bottom is rounded to relieve stress concentration. The groove portion 14 a is, for example, a notch formed in the rear lid 9 at the time of machining such as cutting after manufacturing the rear lid 9 or molding processing such as casting at the time of manufacturing the rear lid 9. As shown in FIG. 3, the groove portion 14a is a slide on which the lip 11a slides on the outer peripheral surface 9c so that the lubricant does not leak between the outer peripheral surface 9c of the rear lid 9 and the lip 11a of the oil seal 11B. It is formed on the non-sliding surface 9i other than the moving surface 9h.

Next, the operation of the bearing wear preventing structure according to the first embodiment of the present invention will be described.
As shown in FIG. 4 (B), when the anti-wear structure 12 does not exist in the rear lid 9, when the vehicle travels on the track and the bending moment M acts on the axle 1, the shaft end side of the axle 1 is bent. Mu For this reason, when the rear cover 9 rotates together with the axle 1 and the edge of the rear cover 9 on the outer peripheral surface 9c side is positioned downward, the contact surface 9a of the rear cover 9 and the contact surface 3g on the bearing 3 side are located. Are partially biased at the lower edge. As a result, repeated stress acts on the lower edge of the contact surface 9a of the rear cover 9 and the contact surface 3g on the bearing 3 side, and foreign matter such as fretting wear powder is generated due to wear of the bearing 3 and the rear cover 9. To do. Further, as shown in FIG. 5B, when the rear cover 9 has no wear prevention structure 12, when the rear cover 9 is press-fitted into the axle 1, the opposite end side of the rear cover 9 is deformed, and the rear cover 9 The rear lid 9 is attached to the axle 1 with the contact surface 9a of 9 being warped. For this reason, the edge of the contact surface 9a of the rear lid 9 on the outer peripheral surface 9c side comes into partial contact with the contact surface 3g on the bearing 3 side, and the wear of these contact surfaces 3g, 9a causes fretting wear powder. Foreign matter is generated.

  On the other hand, as shown in FIG. 4A, when the wear prevention structure 12 exists in the rear cover 9, the rear cover 9 bends at the flexible portion 13 following the bending of the axle 1. For example, the rear lid 9 is elastically deformed so that the opening side of the groove portion 14 a is opened near the upper portion of the rear lid 9, and the rear lid 9 is elastically deformed so that the opening portion side of the groove portion 14 a is closed near the lower portion of the rear lid 9. For this reason, the contact surface 9a of the rear lid 9 comes into contact with the contact surface 3g on the bearing 3 side substantially uniformly, the contact surface pressure of these contact surfaces 3g, 9a becomes substantially uniform, and these contact surfaces 3g, 9a It is possible to prevent foreign matter from being generated due to wear. In addition, as shown in FIG. 5B, when the rear cover 9 has the wear prevention structure 12, if the rear cover 9 is press-fitted into the axle 1, the opposite end side of the rear cover 9 is deformed. The rear lid 9 bends at the flexible portion 13 following the deformation of 9. For example, the rear lid 9 is elastically deformed so that the opening portion side of the groove portion 14a is closed at the edge portion of the rear lid 9 on the outer peripheral surface 9c side. For this reason, the contact surface 9a of the rear lid 9 comes into contact with the contact surface 3g on the bearing 3 side substantially uniformly, the contact surface pressure of these contact surfaces 3g, 9a becomes substantially uniform, and these contact surfaces 3g, 9a It is possible to prevent foreign matter from being generated due to wear.

The bearing wear preventing structure according to the first embodiment of the present invention has the following effects.
(1) In the first embodiment, the contact surface 3g on the bearing 3 side and the contact surface 9a on the rear lid 9 side are approximately when the pressing force is applied in the direction in which the bearing 3 and the rear lid 9 are in close contact with each other. The flexible portion 13 bends the rear lid 9 so as to make uniform contact. For this reason, for example, the axle 1 bends as shown in FIG. 4B, or the non-shaft end side of the rear lid 9 deforms as shown in FIG. When 3g and the contact surface 9a on the rear lid 9 side are in contact with each other, as shown in FIGS. 4A and 5A, the contact surface 3g on the bearing 3 side and the contact surface 9a on the rear lid 9 side are provided. Can be made substantially uniform. As a result, the occurrence of fretting wear and the like on the contact surface 3g of the bearing 3 and the contact surface 9a of the rear lid 9 can be prevented.

(2) In the first embodiment, the flexible portion 13 is a thin portion of the rear lid 9. For this reason, the bending rigidity of the rear lid 9 can be partially reduced to flex the flexible portion 13 easily. As a result, when a pressing force is applied in the direction in which the bearing 3 and the rear lid 9 are in close contact with each other, the bearing 3 and the rear lid 9 can be brought into substantially uniform contact.

(3) In the first embodiment, a plurality of grooves 14 a are formed in the circumferential direction of the outer peripheral surface 9 c of the rear lid 9 with a predetermined interval in the length direction of the rear lid 9. For this reason, the groove part 14a is formed in the existing rear cover 9 or a new rear cover 9 by machining such as cutting, or the groove part 14a is formed simultaneously with the molding process when the rear cover 9 is manufactured by molding process such as casting. You can do it. As a result, the flexible portion 13 can be formed in the circumferential direction of the outer peripheral surface 9c of the rear lid 9 by simple processing.

(4) In the first embodiment, the flexible portion 13 is formed on the rear lid 9 that comes into contact with the inner ring 3 d of the bearing 3. For this reason, it is possible to suppress the generation of fretting wear powder and to prevent the fretting wear powder from entering the inside of the bearing 3 only by performing a simple process on the rear lid 9.

(Second Embodiment)
In the following, the same parts as those shown in FIGS. 1 to 5 are denoted by the same reference numerals and detailed description thereof is omitted.
Unlike the flexible portion 13 shown in FIG. 2, the flexible portion 13 shown in FIG. 6A has a predetermined interval in the length direction of the rear lid 9 (a direction parallel to the central axis O of the axle 1). Thus, a plurality of groove portions 14 a formed in the circumferential direction of the inner peripheral surface 9 b of the rear lid 9 are provided. The groove portion 14a is formed in a straight line with a predetermined depth on the inner peripheral surface 9b of the rear lid 9 so as to be orthogonal to the central axis O of the rear lid 9, and is formed at the bottom portion to alleviate stress concentration at the bottom portion. Roundness is given.

  The flexible portion 13 shown in FIG. 6B is different from the flexible portion 13 shown in FIGS. 2, 3 and 6A in the length direction of the rear lid 9 (parallel to the central axis O of the axle 1). A plurality of groove portions 14a formed in the circumferential direction of the inner peripheral surface 9b and the outer peripheral surface 9c of the rear lid 9 at a predetermined interval. The flexible portion 13 is configured so that, for example, the groove portion 14a on the inner peripheral surface 9b side and the groove portion 14a on the outer peripheral surface 9c side do not overlap in the thickness direction of the rear lid 9 so that the mechanical strength of the rear lid 9 does not decrease. It is formed alternately. The groove portion 14a is formed in a straight line with a predetermined depth on the inner peripheral surface 9b and the outer peripheral surface 9c of the rear lid 9 so as to be orthogonal to the central axis O of the rear lid 9, and relieve stress concentration at the bottom. Therefore, the bottom is rounded. This second embodiment has the same effect as the first embodiment.

(Third embodiment)
Unlike the flexible portion 13 shown in FIGS. 2B and 3, the flexible portion 13 shown in FIGS. 7B and 8 is formed in the circumferential direction of the outer peripheral surface 9 c of the rear lid 9. A groove portion 14b is provided. In the flexible portion 13 shown in FIGS. 7B and 8, a single groove portion 14b having a width wider than the groove portion 14a shown in FIGS. 2B and 3 is formed in the circumferential direction of the outer peripheral surface 9c. . The groove 14b is formed in a straight line at a predetermined depth on the outer peripheral surface 9c of the rear lid 9 so as to be orthogonal to the central axis O of the rear lid 9, and is rounded at the bottom to alleviate stress concentration at the bottom. Is granted.

The bearing wear prevention structure according to the third embodiment of the present invention has the following effects in addition to the effects of the first and second embodiments.
In the third embodiment, the flexible portion 13 is formed with a single groove portion 14 b in the circumferential direction of the outer peripheral surface 9 c of the rear lid 9. For this reason, compared with 1st Embodiment and 2nd Embodiment, the single groove part 14b can be formed in the circumferential direction of the outer peripheral surface 9c of the rear cover 9 by simple process in a short time.

(Fourth embodiment)
Unlike the flexible portion 13 shown in FIGS. 7 and 8, the flexible portion 13 shown in FIG. 9A includes a groove portion 14 b formed in the circumferential direction of the inner peripheral surface 9 b of the rear lid 9. . As shown in FIG. 9 (A), the groove portion 14b is formed in a straight line with a predetermined depth on the inner peripheral surface 9b of the rear lid 9 so as to be orthogonal to the central axis O of the rear lid 9. In order to alleviate the stress concentration, the bottom is rounded. The flexible portion 13 shown in FIG. 9B is different from the flexible portion 13 shown in FIGS. 7, 8, and 9A in the circumferential direction of the inner peripheral surface 9b and the outer peripheral surface 9c of the rear lid 9. The groove part 14b formed in is provided. In the flexible portion 13, for example, the depth of the groove portion 14b on the inner peripheral surface 9b side and the depth of the groove portion 14b on the outer peripheral surface 9c side are set so that the mechanical strength of the rear lid 9 does not decrease. As shown in FIG. 9B, the groove portion 14b is formed in a straight line with a predetermined depth on the inner peripheral surface 9b and the outer peripheral surface 9c of the rear lid 9 so as to be orthogonal to the central axis O of the rear lid 9. In order to alleviate the stress concentration at the bottom, the bottom is rounded. The fourth embodiment has the same effect as the third embodiment.

(Fifth embodiment)
The bearing assembly 2 shown in FIG. 10 is different from the bearing assembly 2 shown in FIG. 1 in that a plurality of groove portions 14a on the flexible portion 13 side are a plurality of groove portions 15a on the fixed body 15 side as shown in FIG. The labyrinth seal part 16 which seals these gaps is formed by facing the gaps. The sealing structure 7 includes an oil drain 8 shown in FIG. 10, a rear lid 9 shown in FIGS. 10 and 11, seal cases 10A and 10B shown in FIG. 10, oil seals 11A and 11B, and the like. The labyrinth seal portion 16 shown in FIGS. 10 and 11 is provided. The fixed body 15 is a member that is fixed at a predetermined interval from the rear lid 9 that is a rotating body. The fixed body 15 is a casing part which comprises a part of axle box which accommodates the bearing assembly 2, for example. As shown in FIG. 11, the fixed body 15 has a plurality of groove portions 15 a at the same interval (pitch) as the plurality of groove portions 14 a on the flexible portion 13 side at the end on the opposite axis end side.

  The labyrinth seal portion 16 shown in FIG. 11 seals these gaps by opening a predetermined gap between the plurality of groove portions 14a on the flexible portion 13 side and the plurality of groove portions 15a on the fixed body 15 side. Part. The labyrinth seal portion 16 is a non-contact sealing device that prevents the lubricant from leaking from between the rear lid 9 and the fixed body 15. The labyrinth seal portion 16 prevents the lubricant from leaking due to the squeezing action and vortex loss that occur when the gas passes through the gap between the groove portion 14a on the flexible portion 13 side and the groove portion 15a on the fixed body 15 side. . The labyrinth seal part 16 combines the uneven gaps between the rear lid 9 and the fixed body 15 in a plurality of stages to gradually relieve and lower the leakage pressure for each stage.

The bearing wear preventing structure according to the fifth embodiment of the present invention has the following effects in addition to the effects of the first embodiment.
In the fifth embodiment, the flexible portion 13 is spaced at a predetermined interval in the length direction of the rear lid 9, and a plurality of groove portions 14 a are formed in the circumferential direction of the outer peripheral surface of the rear lid 9. Moreover, in this 5th Embodiment, the labyrinth seal part which seals these clearance gaps by making the some groove part 14a by the side of the flexible part 13 oppose the several groove part 15a by the side of the fixing body 15 with a clearance gap. 16 is configured. Therefore, the oil seal 11B as shown in FIGS. 1 and 3 can be omitted, and the plurality of groove portions 14a on the flexible portion 13 side can be used as a part of the labyrinth seal portion 16.

  Finite element analysis was performed on the bearing assemblies including the rear lids according to Examples 1 and 2 and the conventional example. Example 1 shown in FIG. 12 corresponds to the rear cover 9 according to the first embodiment shown in FIGS. 1 to 5 and is a rear cover having three grooves on the outer peripheral surface. Example 2 shown in FIG. 13 corresponds to the rear lid 9 according to the third embodiment shown in FIGS. 7 and 8 and is a rear lid having one groove on the outer peripheral surface. The conventional example shown in FIG. 14 is a conventional rear cover having no groove on the outer peripheral surface. The rear lids according to the first and second embodiments and the conventional example shown in FIGS. 12 to 14 are brought into contact with the inner ring of the bearing in a state where the rear lid is press-fitted to the side opposite to the shaft end from a predetermined position of the axle.

  As shown in FIG. 14, the rear lid according to the conventional example has a high contact surface pressure between the stepped portion between the axle dust seat and the middle diameter portion and the fitting surface of the rear lid, It was confirmed by analysis that the contact surface on the bearing side and the contact surface on the rear lid side are in contact with each other and the contact surface pressure on these contact surfaces is uneven. As a result, the rear lid according to the conventional example is predicted to generate fretting wear between the contact surface on the bearing side and the contact surface on the rear lid side.

  On the other hand, as shown in FIGS. 12 and 13, the rear lids according to the first and second embodiments are provided with a step portion between the dust-proof seat of the axle and the intermediate diameter portion, as in the conventional example shown in FIG. 14. The contact surface pressure with the fitting surface of the rear lid is high. However, as shown in FIGS. 12 and 13, in the rear lids according to the first and second embodiments, the contact surface on the bearing side and the contact surface on the rear lid side are in contact with each other substantially uniformly. The analysis confirmed that the surface pressure was substantially uniform. As a result, it is predicted that the rear lids according to Examples 1 and 2 can suppress the occurrence of fretting wear between the contact surface on the bearing side and the contact surface on the rear lid side.

  The vertical axis shown in FIG. 15 is the contact surface pressure [MPa], and the horizontal axis is the distance [mm] from the inner peripheral surface. As shown in FIG. 15, the rear lids according to Examples 1 and 2 have lower contact surface pressure near the outer peripheral surface than the rear lid according to the conventional example, and from the inner peripheral surface side to the outer peripheral surface side. It was confirmed that the change of the contact surface pressure can be reduced in almost the entire area. In addition, the rear cover according to the second embodiment has a contact surface pressure that is substantially uniform over substantially the entire area from the inner peripheral surface side to the outer peripheral surface side as compared with the rear cover according to the first embodiment. It was confirmed that the occurrence of fretting wear with the contact surface on the rear lid side can be further suppressed.

(Other embodiments)
The present invention is not limited to the embodiment described above, and various modifications or changes can be made as described below, and these are also within the scope of the present invention.
(1) In this embodiment, the wear prevention structure 12 of the bearing 3 of the railway vehicle has been described as an example. However, the present invention is not limited to the bearing 3 of the railway vehicle. For example, the present invention can also be applied to a wear prevention structure for a bearing that supports a rotating shaft such as a turbine of a power plant and a wear prevention structure for a bearing of a main motor that drives the axle 1. Moreover, although this embodiment demonstrated the case where the bearing 3 was a roller bearing, this invention is applicable also when the bearing 3 is a ball bearing. Furthermore, in this embodiment, the case where the bearing 3 is a double row tapered roller bearing has been described as an example, but the present invention can also be applied to a double row cylindrical roller bearing or a spherical roller bearing.

(2) In this embodiment, the case where the contact member that contacts the bearing 3 is the rear lid 9 has been described as an example. However, the present invention is not limited to the rear lid 9. For example, the present invention can be applied to a contact member such as an oil drainer that press-fits the outer peripheral surface of the dust guard 1b and prevents the lubricant in the bearing 3 from leaking to the outside. In this embodiment, the case where the grooves 14a and 14b are formed in a straight line on the inner peripheral surface 9b or the outer peripheral surface 9c of the rear lid 9 perpendicularly to the central axis O of the rear lid 9 will be described as an example. However, the grooves 14a and 14b can be formed in an arbitrary shape such as a tapered shape or a curved shape. Furthermore, in this embodiment, the bearing assembly 2 including the shaft end nut 4 that meshes with the male screw portion at the end of the axle 1 has been described as an example. However, a front lid that suppresses the oil drain 8 is provided at the end of the axle 1. The present invention can also be applied to a bearing assembly that is fixed by a fixing bolt.

(3) In the first embodiment, the second embodiment, and the fifth embodiment, the case where the number of the groove portions 14a is three has been described as an example, but the case where the number of the groove portions 14a is two, or four or more. The present invention can also be applied. In the second embodiment, the case where the grooves 14a are alternately formed on the inner peripheral surface 9b and the outer peripheral surface 9c of the rear lid 9 so as not to overlap in the thickness direction of the rear lid 9 has been described as an example. The groove portions 14b can also be formed on the inner peripheral surface 9b and the outer peripheral surface 9c of the rear lid 9 so as to overlap in the thickness direction of the rear lid 9. Similarly, in the fourth embodiment, the case where the grooves 14b are formed in the inner peripheral surface 9b and the outer peripheral surface 9c of the rear lid 9 so as to overlap in the thickness direction of the rear lid 9 has been described as an example. It is also possible to alternately form the grooves 14b on the inner peripheral surface 9b and the outer peripheral surface 9c of the rear lid 9 so as not to overlap in the thickness direction of the lid 9. Furthermore, in the fifth embodiment, the case where the groove portion 14a on the rear lid 9 side and the groove portion 15a on the fixed body 15 side are opposed to each other so that the concavo-convex portions coincide with each other has been described as an example. It can also be made to oppose so that it may become alternate.

DESCRIPTION OF SYMBOLS 1 Axle 2 Bearing assembly 3 Bearing 3d Inner ring 3g Contact surface 4 Shaft end nut 5 Small lid 6 Non-turn bolt 7 Sealing structure 8 Oil drain 9 Rear lid (contact member)
9a Contact surface 9b Inner peripheral surface 9c Outer peripheral surface 9d, 9e Fitting surface 9f Non-fitting surface 9g Opposing surface 9h Sliding surface 9i Non-sliding surface 10A, 10B Seal case 11A, 11B Oil seal 12 Wear prevention structure 13 Flexible Part 14a, 14b Groove part 15 Fixing part 15a Groove part 16 Labyrinth seal part O Center axis

Claims (6)

A bearing wear prevention structure for preventing wear generated on the contact surfaces when the bearing and the contact member in contact with the bearing contact non-uniformly,
When a pressing force is applied in a direction in which the bearing and the contact member are in close contact with each other, the contact member is bent so that the contact surface on the bearing side and the contact surface on the contact member side are in substantially uniform contact. Providing a flexible part,
Bearing wear prevention structure characterized by. In the bearing wear prevention structure according to claim 1,
The flexible part is a thin part of the contact member;
Bearing wear prevention structure characterized by. In the bearing wear prevention structure according to claim 1 or 2,
The flexible portion includes a plurality of grooves formed in the circumferential direction of the outer peripheral surface and / or inner peripheral surface of the contact member at a predetermined interval in the length direction of the contact member;
Bearing wear prevention structure characterized by. In the bearing wear prevention structure according to claim 1 or 2,
The flexible portion includes a single groove formed in the circumferential direction of the outer peripheral surface and / or inner peripheral surface of the contact member;
Bearing wear prevention structure characterized by. In the bearing wear prevention structure according to claim 1 or 2,
The flexible portion includes a plurality of grooves formed in the circumferential direction of the outer peripheral surface of the contact member at a predetermined interval in the length direction of the contact member.
The plurality of groove portions on the flexible portion side constitute a labyrinth seal portion that seals these gaps by facing the plurality of groove portions on the fixed body side with a gap therebetween,
Bearing wear prevention structure characterized by. In the structure for preventing wear of a bearing according to any one of claims 1 to 5,
The flexible part is formed on a rear lid or oil drain that contacts the inner ring of the bearing;
Bearing wear prevention structure characterized by.