JP2000346077A - Shock absorbing rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To allow a bearing to quickly absorb shock loads applied from outside within the bearing. SOLUTION: This rolling bearing is provided with an inner ring 1 the outer peripheral surface of which is formed of a simple cylindrical surface, an outer ring 2 the inner peripheral surface of which is formed of a simple cylindrical surface, annular floating rings 3, 3 provided between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2, and plural balls 4, 4 arranged between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2 in state where the respective floating rings 3, 3 are put between the balls. The hardness of at least either one of the inner ring 1, the outer ring 2, and plural balls 4, 4 is Hv 300 or less, and based on the shock loads applied from outside, at least either one of these members 1, 2, 4 is allowed to be easily plastically deformed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The shock absorbing rolling bearing according to the present invention is incorporated in various rotating machinery, and even when an impact load is applied from the outside, the rotating machinery is damaged based on the impact load. Used to suppress

[0002]

2. Description of the Related Art Rolling bearings incorporated in various types of rotary machines include an inner ring having an inner raceway on an outer peripheral surface and an outer race having an outer raceway on an inner peripheral surface. A rolling bearing is provided between the inner raceway and the outer raceway. A plurality of rolling elements are movably provided. In order to secure the required bearing life and strength, such rolling bearings are generally subjected to heat treatment such as quenching of the inner and outer rings and the rolling elements to harden each of these members. Have been. By such a heat treatment, the hardness of the inner and outer rings exceeds Hv653, and the hardness of the rolling elements exceeds Hv653. Then, for example, the inner ring can be externally fitted and fixed to a shaft or the like which is a rotating member, and the outer ring can be internally fitted and fixed to a housing or the like which is a fixed member arranged concentrically with the shaft or the like.

[0003]

In the case of the conventional rolling bearing as described above, the hardness (hardness) of each of the above-mentioned components is increased, so that when an external impact load is applied to the rolling bearing, The constituent members are elastically deformed, and the impact load is transmitted from one of the shaft and the like to which the inner ring is externally fitted and fixed and the housing and the like to which the outer ring is internally fixed to the other member. Then, the impact load is transmitted from the other member to another portion of the rotary machine device incorporating the rolling bearing. Therefore, if the impact load externally applied to the rolling bearing is excessive, a part of the rotary machine may be damaged, and in a severe case, the entire rotary machine may be damaged. In view of such circumstances, the shock absorbing rolling bearing of the present invention has been invented so as to rapidly absorb an impact load applied from the outside inside the bearing.

[0004]

A shock absorbing rolling bearing according to the present invention comprises an inner ring having an inner raceway on an outer peripheral surface, an outer race having an outer raceway on an inner peripheral surface, and a rolling arrangement between the inner raceway and the outer raceway. A plurality of rolling elements movably provided. The hardness of at least the inside of at least one of the inner ring, the outer ring, and the rolling elements is set to Hv300 or less (preferably, Hv200 or less), and at least one of the inner ring, the outer ring, and the plurality of rolling elements is set. Such a member is easily plastically deformed based on an impact load applied from the outside.
Preferably, the hardness of the surface layer of the member which is easily plastically deformed based on an impact load applied from the outside by setting the internal hardness to Hv300 or less and Hv400 or more to Hv80 or less.
0 or less (more preferably, Hv400 or more, Hv600
Below). The surface layer refers to a portion having a thickness of 2% or less of the diameter of the rolling element incorporated in the rolling bearing (the same applies not only to the surface of the rolling element but also to the surfaces of the inner ring and the outer ring).

[0005]

In the case of the shock absorbing rolling bearing of the present invention configured as described above, the hardness of at least the inside of at least one of the inner ring, the outer ring and the rolling element is set to Hv300 or less (preferably Hv200 or less). Since at least one of the constituent members (for example, a rolling element) is easily plastically deformed based on an impact load applied from the outside, at least one of the constituent members (for example, The rolling element is plastically deformed by the impact load, thereby suppressing elastic deformation. Therefore, it is possible to prevent the impact load from being transmitted from the inner ring to the outer ring or from the outer ring to the inner ring via the plurality of rolling elements, and to use the energy of the impact load for plastic deformation of each of the constituent members. Can be. Therefore, the shock load applied to the shock-absorbing rolling bearing from the outside is rapidly absorbed inside the shock-absorbing rolling bearing, and the damage of the rotating machine incorporating the shock-absorbing rolling bearing is suppressed. Nature can be secured.

[0006]

FIG. 1 shows a first embodiment of the present invention.
An example is shown. The impact-absorbing rolling bearing of the present invention includes:
The vehicle includes an inner ring 1 having outer and outer peripheral surfaces that are simply cylindrical surfaces, and an outer ring 2 having inner and outer peripheral surfaces that are simply cylindrical surfaces. Further, between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2, each inner diameter is larger than the outer diameter of the inner ring 1, and the outer diameter is smaller than the inner diameter of the outer ring 2. Are provided. Both side surfaces of each of the floating wheels 3, 3 are flat surfaces. Then, in a state where the floating wheels 3 are sandwiched, a plurality of balls 4, 4 are arranged in each row between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2 in a double row. It is provided so that it can roll freely. Therefore,
In the case of this example, the outer peripheral surface of the inner ring 1
Correspond to the outer raceways. Further, annular spacers 5, 5 are externally fitted and fixed to the outer peripheral surfaces of both ends of the inner ring 1 in a state where they are present between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2, respectively. , A plurality of balls 4, 4 and a floating wheel 3,
3 is prevented from falling out between the outer peripheral surface of the inner ring 1 and the inner peripheral surface of the outer ring 2. Both side surfaces of the spacers 5, 5 are flat surfaces similarly to the floating wheels 3, 3. For example, the inner ring 1 can be externally fitted and fixed to a rotating member, such as a shaft (not shown), and the outer ring 2 can be internally fixed to a housing (not shown), which is a fixing member arranged concentrically with the shaft or the like. And

Further, in the case of the shock absorbing rolling bearing of the present invention, the hardness of at least one of the inner ring 1, the outer ring 2, and the plurality of balls 4, 4 is set to Hv300 or less (preferably Hv200 or less). I have. For this reason, in the case of the present example, the inner ring 1 and the outer ring 2 are used in a raw state without being subjected to a heat treatment after the carbon steel, the bearing steel or the like is processed into a predetermined shape and size. In addition to the above-mentioned balls 4 and 4, the steel is used after being processed to a predetermined shape and size in a raw state without being subjected to a heat treatment, and is used for a hardened and tempered ordinary ball bearing. By annealing the steel balls, the hardness can be reduced to be lower than that of a conventional general rolling bearing. Therefore, as these balls 4, 4, it is only necessary to anneal a finished steel ball generally used for a ball bearing in the past, and it is not necessary to particularly increase the manufacturing cost. The inner ring 1, the outer ring 2, and the balls 4, 4 may be made of a metal having a low hardness, such as an aluminum alloy or brass, so that the hardness may be set to a low value as described above. And
As described above, by lowering the hardness of each of the constituent members 1, 2, and 4, the constituent members 1, 2, and 4 are easily plastically deformed based on an impact load applied from the outside.

In the case of the shock absorbing rolling bearing of the present invention configured as described above, the hardness of at least one of the inner ring 1, the outer ring 2, and the plurality of balls 4, 4 is set to Hv300 or less (preferably Hv200). Since the constituent members 1, 2, and 4 (for example, the balls 4, 4) are easily plastically deformed based on an externally applied impact load, the constituent members 1, 2, and 4 (for example, the balls 4 and 4) are plastically deformed based on the impact load, thereby suppressing elastic deformation. Therefore, it is possible to prevent the impact load from being transmitted from the inner ring 1 to the outer ring 2 or from the outer ring 2 to the inner ring 1 via the plurality of balls 4, and to transfer the energy of the impact load to each of the constituent members. 1, 2, and 4 can be spent on plastic deformation. Therefore, the shock load applied from the outside to the shock absorbing rolling bearing is quickly absorbed inside the shock absorbing type rolling shaft, and the damage of the rotating machine device incorporating the shock absorbing rolling bearing is suppressed. Reliability can be ensured. If the hardness of the balls 4, 4 is set to Hv 200 or less, the balls 4, 4 are more likely to be plastically deformed, and the degree of absorbing the impact load inside the shock absorbing rolling bearing can be increased. it can.

On the other hand, in a member which is easily plastically deformed, if the hardness of the surface layer is Hv300 or less, the wear resistance may be insufficient. Therefore, when the operating conditions as a rolling bearing are severe, such as when the operating rotational speed is high, or when the load applied during rotary use is large,
In order to improve wear resistance, the surface layer of the raceway surface or rolling surface is Hv
400 or more and Hv800 or less (more preferably, Hv4
00 or more and Hv600 or less). However, if the thickness of the surface layer having high hardness is large, plastic deformation is unlikely to occur when an impact is applied, so the thickness of the surface layer is not limited to the rolling elements, but is applied to the inner ring and the outer ring. At least 2% of the diameter of the rolling element incorporated in the rolling bearing.
Note that the hardness of the surface layer of the raceway surface or the rolling surface is Hv400 or more and Hv800 or less (preferably, Hv400 or more, Hv
As a method for setting the temperature to v600 or less, a soft nitriding treatment (salt bath nitriding treatment, gas nitriding treatment, plasma nitriding treatment), carburizing treatment, carbonitriding treatment, plating treatment, or the like can be adopted.

Further, in the case of the illustrated shock absorbing rolling bearing,
Since the inner and outer orbits, which are the mating surfaces on which the balls 4 and 4 roll, are formed only by a part of a cylindrical surface, the inner and outer orbits are generally formed in an arc-shaped groove. The contact pressure of each ball 4, 4 can be higher than in the case of a conventional ball bearing. Therefore, each of the above components 1, 2, and 4 is more likely to be plastically deformed based on an externally applied impact load, and the externally applied impact load is rapidly absorbed inside the impact absorbing rolling bearing, and this impact absorbing It is possible to further suppress damage to the rotating machine device incorporating the rolling bearing. In this case, no special processing is required to form the inner raceway and the outer raceway on the inner race 1 and the outer race 2, and the plurality of ball rows are separated from each other by the annular floating wheels 3. Therefore, the production cost is not significantly increased because a double-row type shock absorbing rolling bearing is configured.

The shock-absorbing rolling bearing of this embodiment has an inner ring 1
The present invention is applied to a double-row ball bearing in which a plurality of ball rows are arranged between the outer circumferential face of the inner race 1 and the inner circumferential face of the outer race 2, wherein the outer circumferential surface of the inner race and the inner circumferential surface of the outer race 2 are merely cylindrical surfaces. Is shown in the case where is applied. However, in addition to the structure of this example, in a general ball bearing in which both the inner and outer raceways are groove-shaped with a circular cross section, the hardness of the inner ring 1, the outer ring 2, and the balls 4, 4 is respectively set. It may be configured by regulating as described above. In a roller bearing using rollers such as cylindrical rollers, conical rollers, spherical rollers, and needle rollers instead of the balls 4 and 4 as rolling elements, The hardness of the inner ring and the outer ring may be regulated as described above. In any case, when implementing the present invention, by providing the rolling elements in a double row, the surface pressure acting on the contact portion between the rolling surface of these rolling elements and the mating raceway surface during normal operation is reduced. This prevents the contact portion from being plastically deformed in a normal use state.

[0012]

Since the shock absorbing rolling bearing of the present invention is constructed and operates as described above, the shock load applied from the outside is rapidly absorbed inside, and the present invention is applied to a rotating machine device incorporating the shock absorbing rolling bearing. Damage can be suppressed, and the reliability of the rotating mechanical device can be ensured.

[Brief description of the drawings]

FIG. 1 is a half sectional view showing an example of an embodiment of the present invention.

[Explanation of Signs] 1 inner ring 2 outer ring 3 floating wheel 4 ball 5 spacer

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masafumi Fukunaga 1-5-50 Kumeinuma Shinmei, Fujisawa-shi, Kanagawa F-term in NSK Ltd. (reference) 3J101 AA02 AA31 AA44 AA52 AA62 BA10 BA70 EA02 EA03 EA13 EA14 FA31 FA60

Claims (2)

[Claims] An inner race having an inner raceway on an outer peripheral surface, an outer race having an outer raceway on an inner peripheral surface, and a plurality of rolling elements rotatably provided between the inner raceway and the outer raceway. The hardness of at least the inside of at least one of the inner ring, the outer ring, and the rolling elements is set to Hv300 or less, and at least one of the inner ring, the outer ring, and the plurality of rolling elements is externally applied. Shock-absorbing rolling bearing that is easily plastically deformed based on impact load. 2. The impact-absorbing rolling according to claim 1, wherein the hardness of the surface layer of the member whose internal hardness is set to Hv300 or less and plastic deformation is facilitated based on an externally applied impact load is set to Hv400 or more and Hv800 or less. bearing.