JP2006194402A - Rolling bearing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rolling bearing device capable of more securely guiding lubricating oil to a space between a rolling element and a bearing ring and therefore, making the supplied lubricating oil more efficiently contribute to lubrication, compared to a conventional rolling bearing device having a self-lubricating function. <P>SOLUTION: This rolling bearing device is provided with a lubrication unit 4 for supplying lubricating oil inside a tank 41 by means of a pump 42 via a nozzle 43 opened within an annular space between an inner ring 11 and an outer ring 12. The nozzle 43 is opened within the space between an inner peripheral face 14a of a cage 14 and the inner ring 11, and the inner peripheral face 14a of the cage 14 is formed to be a face of which diameter is continuously or intermittently reduced gradually from an axial center part at least toward an insertion side end part of the nozzle 43. Due to this, lubricating oil dropped on the inner peripheral face 14a of the cage 14 by centrifugal force by rotation of the cage 14 is flowed toward the axial center part to prevent outflow to outside the bearing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rolling bearing device having a self-lubricating function.

  For example, rolling bearings such as angular ball bearings are used to support shafts that rotate at a relatively high speed, such as various spindles used in machine tools and the like. As a lubricating method for such a rolling bearing that supports a high-speed rotating shaft, an oil-air lubrication method has been frequently used conventionally.

  The oil-air lubrication system is a system in which a small amount of lubricating oil supplied intermittently is blown toward the rolling bearing with compressed air through a pipe, and the air curtain formed around the rolling bearing rotating at high speed is pushed. In order to supply lubricating oil to the bearings, compressed air is used as a carrier.

  In such an oil / air lubrication system, an oil / air lubrication device, a mixing valve, a compressor and external piping are required outside the spindle in which the rolling bearing to be lubricated is incorporated. There is a problem that not only the cost is increased due to the need to form a passage for the vehicle, but also the noise level is increased due to the use of compressed air.

  In order to solve such a problem, a rolling bearing device in which a lubrication supply mechanism is built in the rolling bearing has been proposed (see, for example, Patent Document 1).

  In this proposed technology, a tank and a pump for storing lubricating oil are mounted on the fixed wheel side, and a nozzle that extends and opens to the immediate vicinity of the rolling element that rolls between the inner and outer rings is attached to the pump. For example, an extremely small amount of lubricating oil of about several tens of nl (several tens of μcc) is dropped toward the rolling elements. With this configuration, since the lubricating oil is supplied to the inside of the air curtain that is generated when the rolling bearing rotates, the compressed air as a carrier is unnecessary as in the oil-air lubrication method, and the problem of noise can be solved. In addition, the compressor, the oil / air lubrication device, and the external piping and the internal piping are not required, which is advantageous in terms of cost.

  In this type of rolling bearing device with a lubricating function, an important issue is how to efficiently contribute the lubricating oil supplied from the nozzle to the lubrication between the rolling elements and the race. Since the rotating wheel, rolling element and cage of the rolling bearing are rotating at a high speed, the lubricating oil supplied and adhering to any of these is subjected to a force away from the center of rotation (hereinafter referred to as centrifugal force). In some cases, it may be difficult to flow between the raceway and the rolling element. A suitable arrangement of the nozzles in consideration of such centrifugal force is a position as illustrated in an axial parallel cross-sectional view in FIG. In the example of FIG. 6, the lubricating oil is provided in the spacer 65 arranged in the immediate vicinity of the rolling bearing having the inner ring 61, the outer ring 62, the rolling elements 63 and the cage 64 as main constituent elements, for example, adjacent to the outer ring 62 which is a fixed ring. Are attached to a tank (not shown) for storing the oil, a pump 66 for sucking and discharging the lubricating oil in the tank, and a discharge port of the pump 66, and an inner peripheral surface of the retainer 64 and an outer peripheral surface of the inner ring 61. The structure is such that an oil supply unit consisting of a nozzle 67 extending to the middle and opening at the tip of the nozzle 67 and a drive unit (not shown) of the pump 66 is fixed.

According to such an arrangement of the nozzle 67, the lubricating oil supplied from the tip opening to the inner peripheral surface of the cage is directed toward the raceway surface of the outer ring 62 through the rolling element 63 by the centrifugal force generated by the rotation of the rolling bearing. While moving, it is also transferred to the raceway surface of the inner ring 61 via the rolling elements 63, so that the rolling bearing can be effectively lubricated.
JP 2004-108388 A

  By the way, since the lubricating oil supplied from the nozzle opening inside the rolling bearing is also subjected to the force of the air flow inside the bearing generated by the rotation of the rolling bearing in addition to the centrifugal force, the nozzle as shown in FIG. Even if most of the arrangement is adopted and supplied to the inner peripheral surface of the cage 64, due to the turbulence of the air flow inside the rolling bearing, etc., as indicated by the arrows in FIG. On the inner peripheral surface, it may flow toward the opposite side of the rolling element 63 and flow out of the bearing, and it is difficult to say that the total amount contributes to the lubrication of the rolling bearing.

  The present invention has been made in view of such circumstances, as compared to a conventional rolling bearing device having a self-lubricating function, the lubricating oil can be more reliably guided between the rolling elements and the raceway, Accordingly, an object of the present invention is to provide a rolling bearing device capable of more efficiently contributing the lubrication oil supplied to the lubrication.

  In order to solve the above-described problems, a rolling bearing device according to the present invention is arranged between an inner ring and an outer ring so that a plurality of rolling elements can be rolled in a state where the rolling elements are held at a constant pitch in a circumferential direction by a cage. A rolling bearing, a nozzle communicating with a tank for storing lubricating oil and opening in an annular space formed between an inner ring and an outer ring of the rolling bearing, and the lubricating oil in the tank via the nozzle In the rolling bearing device having a pump for supplying the rolling bearing to the rolling bearing, the nozzle is inserted and opened in a space between the inner circumferential surface of the cage and the inner ring, and the inner circumferential surface of the cage is a shaft. This is characterized in that the diameter gradually decreases continuously or intermittently from the center in the direction toward the end surface on the nozzle insertion side (claim 1).

  Here, in the present invention, the inner circumferential surface of the retainer is gradually or intermittently reduced in diameter from the axial center to the opposite end surface also on the side opposite to the nozzle insertion side. The structure (Claim 2) which becomes can also be employ | adopted.

  The present invention provides an inner peripheral surface of the cage by gradually reducing the inner peripheral surface of the cage, that is, the surface facing the outer circumferential surface of the inner ring, from at least the nozzle insertion side toward the end surface portion in the axial direction. A force directed toward the center in the axial direction of the bearing is applied to the lubricating oil supplied toward the center by centrifugal force to prevent scattering to the outside of the bearing.

  That is, a nozzle for supplying lubricating oil is inserted and opened in the space between the cage and the inner ring, and the inner diameter of the cage is the axial dimension of the cage at the end surface portion on the insertion side of the nozzle. Lubricating oil supplied to the inner peripheral surface of the cage is tapered by a taper surface or a stepped surface or curved surface corresponding to the taper surface that gradually or intermittently decreases with respect to the inner diameter of the central portion. The force toward the axial center acts by the centrifugal force generated by the rotation of the cage accompanying the rotation of the bearing, and the amount of lubricating oil flowing out of the bearing can be reduced or eliminated.

  Further, as in the invention according to claim 2, the tapered inner surface or the stepped surface having a smaller diameter toward the end side equivalent to the above also on the inner peripheral surface of the cage opposite to the insertion direction of the nozzle in the axial direction. Alternatively, by using a curved surface, even if the lubricating oil supplied from the nozzle discharge port to the inner peripheral surface of the cage moves beyond the center in the axial direction toward the opposite side, the lubricating oil is transferred from the opposite end surface to the outside of the bearing. It is possible to prevent outflow.

  According to the present invention, in the rolling bearing device having the function of inserting the nozzle into the annular space between the inner and outer rings of the rolling bearing and supplying the lubricating oil in the tank directly into the rolling bearing, As a result of suppressing the oil outflow to the outside of the bearing, the use efficiency of the lubricating oil is improved, and the life of a type that cannot replenish the lubricating oil in the tank storing the lubricating oil is improved. In addition, in the type that can replenish the lubricating oil, the lubricating oil replenishment interval can be lengthened.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an axially parallel sectional view of an embodiment of the present invention, and FIG. 2 is a left side view of an outer ring spacer 3.

  This example shows an example in which the oil supply unit 4 is arranged in the outer ring spacer 3 which is the fixed side spacer among the inner ring spacer 2 and the outer ring spacer 3 which are arranged adjacent to the angular ball bearing 1. ing.

  The angular ball bearing 1 has a structure in which a plurality of rolling elements (balls) 13 are held between an inner ring 11 and an outer ring 12 by a retainer 14 at regular intervals in the circumferential direction. In this example, the outer ring 12 is a fixed ring. The shaft S is fixed to the inner peripheral surface of the inner ring 11.

  The oil supply unit 4 disposed in the outer ring spacer 3 communicates with a tank 41 for storing lubricating oil, and a pump 42 that communicates with the tank 41 via a pipe 41a and sucks and discharges the lubricating oil in the tank 41. The nozzle 43 attached to the discharge port of the pump 42 and the drive circuit 44 of the pump 42 are mainly configured, and these are fixed along the inner peripheral surface of the outer ring spacer 3. As shown in FIG. 1, the nozzle 43 is inserted into the space between the inner ring 11 and the cage 14 from one axial end side of the rolling bearing 1, and the tip opening 43 a is formed on the inner peripheral surface 14 a or the cage 14. An opening is formed between the rolling element 13 and the outer peripheral surface 11 a of the inner ring 11.

  An example of the entire configuration of the fuel supply unit 4 is shown in FIG. 3 together with a schematic diagram showing a mechanical configuration and a block diagram showing an electrical configuration.

  The pump 42 includes a pump chamber 42a, a diaphragm 42b that forms a part of the wall of the pump chamber 42a, a piezoelectric element 42c attached to the diaphragm 42b, and a connection portion between the pump chamber 42a and the pipe 41a. The check valve 42d is formed. The drive circuit 44 includes a power supply battery 44a and supplies, for example, a rectangular voltage signal to the piezoelectric element 42c. In this configuration, when a rectangular voltage signal is applied to the piezoelectric element 42c, the diaphragm 42b is displaced up and down in the drawing. When the diaphragm 42b is displaced upward, the lubricating oil in the tank 41 is sucked into the pump chamber 42a via the check valve 42d and the pipe 41a, and when the diaphragm 42b is displaced downward, the lubricating oil in the pump chamber 42a is supplied to the nozzle 43. Then, the liquid is discharged toward the inner peripheral surface of the cage 14 from the tip opening 43a of the nozzle 43. When the lubricating oil is discharged from the pump 42, the lubricating oil in the pump quality 42a does not return to the pipe 41a side due to the presence of the check valve 42d. The supply amount of the lubricating oil to the angular ball bearing 1 is a very small amount of about 30 nl (30 μcc). Depending on the use conditions, the supply amount of the lubricating oil can be changed from several hundred pl to several hundreds nl.

  The greatest feature of this embodiment is the shape of the inner peripheral surface 14a of the cage 14 of the angular ball bearing 1. The retainer 14 is a resin-made machined retainer having a substantially cylindrical shape as a whole, and pockets 14b for accommodating the rolling elements 13 formed in the cylindrical portion at regular intervals. The surface is a tapered surface in which the inner diameter dimension of both end portions is smaller than the inner diameter dimension of the axial center portion, and both sides of the axial center portion are smaller in diameter toward the end portions.

  According to the above-described embodiment of the present invention, the lubricating oil discharged from the tip opening 43a of the nozzle 43 is supplied onto the inner peripheral surface 14a of the cage 14, and by the action of centrifugal force due to the rotation of the cage 14, Most of the fluid flows on the inner peripheral surface 14a of the cage 14 toward the center in the axial direction, does not flow to the end side, and does not flow out of the bearing. Then, the lubricating oil flowing toward the axial center of the inner peripheral surface 14a of the cage 14 reaches the pocket 14b and adheres to the surface of the rolling element 13, and by its rotation and revolution, the raceway surface of the outer ring 12 and the inner ring 11 are retained. Is guided to the raceway surface and spreads over the entire angular ball bearing 1 to efficiently lubricate it.

  Here, in the above embodiment, the shape of the inner peripheral surface 14a of the cage 14 is a tapered surface in which the inner diameter dimension becomes smaller toward the end portion on both sides of the center in the axial direction. Even when the lubricating oil supplied to the inner peripheral surface 14a on the insertion side of the nozzle 43 flows to the opposite side beyond the central portion in the axial direction, it is prevented from flowing out of the bearing from the opposite end. However, the opposite tapered surface is not necessarily provided. FIG. 4 shows an example thereof in an axial parallel sectional view. In this example, the inner peripheral surface 14a of the retainer 14 has a tapered surface similar to the above between the end portion on the insertion side of the nozzle 43 and the central portion in the axial direction. The inner peripheral surface between the central portion is a cylindrical surface. Even with such a configuration, the same operational effects as the previous example can be obtained depending on the use conditions of the bearing.

  Moreover, in the above embodiment, although the example which arrange | positioned the oil supply unit 4 adjacent to the exterior of the angular ball bearing 1 was shown, you may arrange | position inside a bearing so that an axial parallel sectional view may be shown in FIG. . That is, in the example of FIG. 5, one end side of the inner ring 101 and the outer ring 102 in the angular ball bearing 10 including the inner ring 101, the outer ring 102, the rolling element 103 and the cage 104 is extended in the axial direction as in the previous example. Thus, the width dimension is lengthened, and an oil supply unit 4 equivalent to the previous example is disposed in the extended portion of the outer ring 102. Also in this example, the nozzle 43 attached to the discharge port of the pump 42 is inserted between the inner peripheral surface 104a of the retainer 104 and the inner ring 101 and opened at the tip, and the inner periphery of the retainer 104 The surface 104a is a tapered surface having a smaller diameter toward the end side, and can exhibit the same effects as the above-described examples.

  Further, in each of the above embodiments, the inner peripheral surface of the cage is a tapered surface having a smaller diameter toward the end portion side. However, a substantially curved surface or curved surface that gradually decreases in diameter toward the end portion side. Needless to say, the same effects can be obtained.

  Furthermore, in each of the above embodiments, an example in which an angular ball bearing is used as a rolling bearing has been shown. However, the rolling bearing device of the present invention can be equally applied to a rolling bearing other than the angular ball bearing. Needless to say.

It is an axial parallel sectional view of an embodiment of the invention. It is a left view of the outer ring spacer 3 in FIG. It is a figure which shows the example of whole structure of the oil supply unit in embodiment of this invention, and is the figure which shows together the schematic diagram showing a mechanical structure, and the block diagram showing an electric structure. It is an axis parallel sectional view of other embodiments of the present invention. It is an axial parallel sectional view of further another embodiment of the present invention. It is an axial parallel sectional view showing a configuration example of a conventional rolling bearing device with a lubricating function.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,10 Angular contact ball bearing 11,101 Inner ring 12,102 Outer ring 13,103 Rolling body 14,104 Cage 14a, 104a Inner peripheral surface 2 Inner ring spacer 3 Outer ring spacer 4 Oil supply unit 41 Tank 42 Pump 43 Nozzle 43a Tip opening 44 Drive circuit

Claims (2)

Between the inner ring and the outer ring, a plurality of rolling elements are communicated with a rolling bearing in which the rolling elements are arranged so as to be able to roll while being held at a constant pitch in the circumferential direction by a cage, a tank for storing lubricating oil, and In the rolling bearing device comprising a nozzle that opens in an annular space formed between the inner ring and the outer ring of the rolling bearing, and a pump that supplies the lubricating oil in the tank to the rolling bearing through the nozzle.
The nozzle is inserted and opened between the inner peripheral surface of the cage and the inner ring, and the inner peripheral surface of the cage is continuous from the axial center to the end surface on the nozzle insertion side or A rolling bearing device having a gradually decreasing diameter.   The inner peripheral surface of the retainer also has a gradually decreasing diameter continuously or intermittently from the axial center to the opposite end surface on the side opposite to the nozzle insertion side. The rolling bearing device according to claim 1.

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