JP2681354B2 - Bearing fixing device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a bearing fixing device for fixing an axle end of a railway vehicle. (Prior Art) A roller bearing for an axle of a railroad vehicle has, for example, a cylindrical roller bearing (2) at an axial end of an axle (1) as shown in FIG.
a) to the shaft end, and from the inside to the rollers (2b) and outer ring (2
c), the axle box (12) are arranged in this order, and the separate collar ring (3) is fixed by abutting against the inner ring (2a), and the axial movement of the roller can be supported by the outer edge of the collar ring. Thus, the roller bearing is constituted, and the collar ring is used as the bearing retaining ring. In addition, the collar ring (3) is fixed to the inner ring (2a) by the bearing retainer nut (5) shown in FIG. 12 which is screwed into the male screw (4) provided around the shaft end of the axle (1) shown in FIG. Is being held down. Furthermore, in order to prevent looseness of the bearing retainer nut (5), as shown in FIG. 11, a large number of screw holes (6) equally distributed in the circumferential direction of the bearing retainer nut (5) are provided on the retaining ring (10). A key (9) having a through hole (7) formed therein and formed on the inner circumference corresponding to the key groove (8) formed in the male thread (4) of the shaft end shown in FIG. 13 in the longitudinal direction. And insert the retaining ring (10) into the shaft end. Also, the through hole of the retaining ring (7)
There was one in which the roller bearing (2) was fixed to the shaft end by screwing in the bolt (11). The assembly order is as shown in FIG. Further, (13) shown in FIG. 10 shows a front lid. Further, as shown in FIG. 14, the inner ring (2a) is fixed to the shaft end of the axle (1), and the rollers (2b), the outer ring (2c) and the saddle (17) are arranged in this order from the inside. There was a built-in tapered roller bearing (2). The inner ring (2) has a seal contact ring fixed by a front lid (13) attached to the shaft end with a bolt (11).
The bearing is fixed by using the seal contact ring as a bearing retaining ring by fixing the bearing while pressing it against a). In addition, (15) shows a rear lid and (16) shows an air breather. (Problems to be solved by the invention) However, recently, since the traveling speed of the vehicle is increased and the traveling distance is extended, vibration and lateral movement during traveling are increased, and this has a large influence on the bearing. It was In addition to this, there is a tendency to extend the inspection cycle in order to rationalize the inspection of bearings, which causes looseness of the bearing retainer nuts or shaft end bolts that secure the bearing, escape of the bearing retainer nut, and wear of the shaft end screw. Complete measures are required to prevent such occurrences. However, the current situation is not always satisfactory, and since the above-mentioned problems often occur,
It was necessary to remove the front cover of the axle box and re-tighten the bearing retainer nut every 400,000 km / month. (Means for Solving Problems) It has been conventionally considered that looseness of a bearing pressing nut and damage to a screw are caused by a thrust force acting on the nut during traveling of the vehicle. However, the radial load of the bearing is usually 6,000 Kgf
It is ~ 6,500Kgf, and even if a 50% thrust load is applied, it will be about 3,000Kgf, which should not result in damage to the screws. Therefore, while the vehicle is traveling, the shaft is cooled by traveling wind, but the temperature of the bearing rises in proportion to the speed, a temperature difference occurs between the shaft and the bearing, the inner ring of the bearing expands, and the bearing retaining ring,
Push back on the bearing retainer nut. Since the distance between the inner end of the inner ring on the side opposite to the bearing retainer ring and the bearing retainer ring is larger than the axial gap of the rollers, the gap does not disappear due to body expansion of the rollers. In particular, the screw was investigated by temporarily making a provision that there is a cause of trouble such as loosening of the bearing retainer nut described above and performing a heat cycle by repeating the temperature difference. As a result, it was found that yielding occurred on the joint surface between the shaft and the screw of the nut. Also, when the nut tightening torque was measured, when the heat cycle was not applied, it was found that a torque of 1.2 times or more the tightening torque was required to loosen the nut. I was able to loosen it below 60%. From the above, body expansion of the inner ring etc. due to the temperature difference between the shaft and the bearing acts on the bearing retainer nut, yielding the screw, loosening the nut, and the tightened state between the nut and the shaft disappears. Then, the knowledge that the screw is worn out was obtained. The present invention was made based on the above findings,
A bearing fixing device in which an elastic body is interposed between a bearing retainer ring and a bearing retainer nut that are in contact with a bearing inner race fixed to an axle, and the elastic body acts as a body expansion absorber of the bearing inner race. (Operation) In the present invention, since the elastic body is provided between the bearing retainer ring and the bearing retainer nut, and the elastic body is used as the body expansion absorber of the bearing inner ring, the bearing retainer nut is tightened to 200 Kgf and every 19 minutes. Was repeatedly heated for 1 minute and subjected to a heat cycle, and the temperature difference between the bearing and the axle was set to 50 ° C and tested for 500 hours.
With the conventional product, the loosening torque of the presser nut was 120 Kgf and the yield of the screw joint was about 0.02 mm. On the other hand, in the present invention, the elastic body acts as a body expansion absorber, the holding nut loosening torque is 240 Kgf, and no yielding is observed at the screw connecting portion. This is shown in the diagram in FIG. FIG. 8 shows the case of the conventional product. (Example) Next, the Example of this invention is described about drawing. As shown in FIG. 1 and FIG. 2, a cylindrical roller bearing is incorporated in the shaft end of the axle (1), and the inner ring (2
a) A separate collar ring (3) is installed in contact with the end. Further, at the shaft end, a disc spring (1
8) is inserted and contacts the collar ring. Finally, screw the bearing retainer nut (5) shown in Fig. 4 into the male screw formed at the shaft end, and press and fix it to the inner ring (2a) of the bearing fixed via the collar ring (3) as the bearing retainer ring. To be done. In addition, (12)
Is a shaft box incorporating bearings, and (13) is a front lid. Further, as shown in FIG. 5, a bearing retainer ring (also a collar contact ring and a seal contact ring) is made to abut on the end portion of the inner ring (2a) fixed to the shaft end of the axle (1) of the cylindrical roller bearing (2). 3
a), and a urethane rubber ring (19) that is in contact with the retaining ring, and is also screwed into the male screw (4) formed on the shaft end, and also serves as a front cover bearing bearing nut (5a). The urethane rubber ring (19) is pressed and fixed to the inner ring (2a) of the fixed bearing to fix the bearing to the shaft end. A rubber lid retaining ring (20) is attached to the front lid and bearing retainer nut,
Further, a rubber lid (21) is fitted on the cylindrical portion of the rubber lid stopper ring. Incidentally, (15) is a rear lid, and (16) is an air breather formed on the rear lid. Furthermore, the embodiment shown in FIG. 6 incorporates a tapered roller bearing (2). At the outer end of the inner ring (2a) of the tapered roller bearing at the shaft end of the axle (1), the seal contact ring (1
The urethane rubber ring (19) pressed by the bearing retaining nut (5) that also serves as the front lid and is screwed into the male screw (4) formed on the shaft end of the seal contact ring (1).
It touches 4). The bearing retainer nut (5) may be screwed into the shaft end, the nut may be covered with the front cover (13) and attached to the shaft end by a bolt. (15) is a rear lid, (16) is an air breather formed on the rear lid, (17) is a saddle, (2
2) is a seal. Further, as shown in FIG. 9, an elastic body can be incorporated in the bearing retainer nut (5). That is, a circumferential groove (23) is installed at a position corresponding to a bearing retaining ring such as a collar ring or a seal contact ring, fluid such as gas or oil is sent from the port (24), and the fluid is sealed by the lid ring (25). It is stopped and the fluid is used as an elastic body. An appropriate material such as a metal material or a synthetic resin can be selected for the lid. When the lid ring is made of a synthetic resin material, a rigid body such as a metal can be attached to the lid to provide abrasion resistance. (Effect) In the present invention, the cause of the looseness and escape of the bearing retainer nut, which is adapted to press the inner ring fixed to the axle of the bearing for the railroad vehicle axle via the bearing retainer ring, is vibration or thrust force during vehicle traveling. The bearing retainer ring and the bearing retainer are not based on the knowledge that they occur due to the temperature difference between the temperature rise due to the rotation of the bearing (especially the temperature rise of the bearing inner ring) and the temperature rise of the shaft. Since an elastic body is provided between the nut and the nut to act as a body expansion absorber, the body expansion of the inner ring generated by the heat cycle due to the rotation of the bearing is not transmitted to the bearing retainer nut. The body expansion did not work on the bearing retainer nut to yield the screw and this kind of trouble was solved. For this reason, it is no longer necessary to remove the front cover of the axle box and press the bearing and re-tighten the nut every 24 months or 400,000 km. Furthermore, not only can the inspection cycle of the entire vehicle be extended to further rationalize it, but there is no risk that the bearing retainer nut will escape during high-speed traveling, hitting a person and causing a serious injury or death. Further, it is not necessary to form the detent keys at the ends of the axles, and a large number of screw holes provided on the outer periphery of the bearing retainer nut for the nut detent are also unnecessary. Moreover, since the present invention has been made without extending the length of the axle, the effect is sufficiently exerted within the vehicle limit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a vertical cross-sectional view of an embodiment of the present invention, FIG. 2 is a partial perspective view showing an assembling order in the present invention, and FIG. 3 (A) is a front view of an elastic body ring, 4B is a sectional view taken along the center line, FIG. 4 is a front view of the bearing retainer nut, FIG. 4B is a sectional view taken along the center line, and FIG. 5 is a longitudinal sectional view according to another embodiment of the present invention. FIG. 6 is a half longitudinal sectional view of still another embodiment, FIG.
The figure shows the change in the tightening torque of the bearing retainer nut after the heat cycle test. Fig. 8 is a diagram corresponding to Fig. 7 of the conventional product. Fig. 9 (a) is a front view of a modified bearing retainer nut. ,
The same figure (b) is a vertical sectional view, and FIG. 10 is a vertical sectional view of a conventional product.
11 (a) is a front view of the retaining ring used in the conventional product, FIG. 11 (b) is a sectional view taken along the line AA of FIG. 12 (a), and FIG. The front view, the same figure (b) is a cross-sectional view taken along the line A-B in the same figure (a), FIG. 13 is a perspective view showing the assembly order of the conventional product, and FIG. 14 is a half longitudinal sectional view of the conventional product. is there. 1 …… Axle 2 …… Rolling bearing 2a …… Inner ring 3 …… Bearing retainer ring (branch ring) 5 …… Bearing retainer nut 14 …… Bearing retainer ring (seal contact ring) 18 …… Elastic body (disc spring) 19 ...... Elastic body (urethane rubber ring)

Claims (1)

(57) [Claims] A bearing retainer ring that is incorporated into the axle end of the axle and that abuts the outer end surface of the bearing inner ring that is fixed to the axle of the rolling bearing that supports the axle and that is screwed into the axle end to press the bearing retainer ring. In a bearing fixing device including a bearing retainer nut that abuts and fixes the bearing inner ring to fix the bearing,
A bearing fixing device characterized in that an elastic body acting as a body expansion absorber of a bearing inner ring due to a temperature difference between a shaft and a bearing is provided between a bearing retainer ring and a bearing retainer nut. 2. The bearing fixing device according to claim 1, wherein the elastic body is rubber. 3. The bearing fixing device according to claim 1, wherein the elastic body is a spring. 4. The bearing fixing device according to claim 1, wherein the elastic body is a fluid enclosed in a nut or a retaining ring.