JP5678632B2 - Rolling bearing device - Google Patents

Description

  The present invention relates to a rolling bearing device lubricated by an oil-air lubrication system.

  Conventionally, for example, a rolling bearing used under high speed rotation, such as a rolling bearing that supports a spindle of a machine tool, in order to reliably lubricate the inside of the bearing, the axial direction from one side of the rolling bearing is directed toward the inside of the bearing. An oil-air lubrication system that supplies lubricating oil together with compressed air is often used (for example, Patent Document 1).

  In the oil-air lubrication method described in Patent Document 1, a discharge hole that opens to the raceway surface and the outer peripheral surface is formed through the central portion in the axial direction of the outer ring of the rolling bearing. The discharge hole communicates with a discharge path formed in the housing, and the lubricating oil supplied to the bearing is discharged through the discharge hole by applying a negative pressure to the inside of the bearing by compressed air flowing through the discharge path. It is sucked into the passage and discharged to the outside of the housing.

Japanese Patent Application Laid-Open No. 2005-133753

In a rolling bearing used under high speed rotation, the lubricating oil supplied to the raceway surface of the outer ring is likely to flow to both axial ends along the inner peripheral surface of the outer ring adjacent to the raceway surface due to centrifugal force accompanying high speed rotation. . On the other hand, in the conventional rolling bearing described in Patent Document 1, since the discharge hole for discharging the lubricating oil is opened in the outer ring raceway surface, the lubricating oil is discharged under high speed rotation. It hardly functions as a flow path, and the lubricating oil tends to stay at both axial ends of the inner peripheral surface of the outer ring. For this reason, the accumulated lubricating oil may flow backward toward the center in the axial direction.In this case, there is a problem that the agitation resistance of the lubricating oil to the rolling elements during rolling increases and bearing torque loss increases. It was.
The present invention has been made in view of the above problems, and an object of the present invention is to provide a rolling bearing device that can reduce the stirring resistance of lubricating oil under high-speed rotation.

In order to achieve the above object, a rolling bearing according to the present invention includes an inner ring having an annular inner ring raceway surface on an outer periphery, an outer ring having an annular outer ring raceway surface on an inner periphery, and the inner ring raceway surface and the outer ring raceway surface. Oil supply for supplying lubricating oil together with compressed air to a rolling bearing having a plurality of rolling elements rolling between, a housing in which the outer ring is fitted, and an annular space between the outer periphery of the inner ring and the inner periphery of the outer ring An oil-air lubrication type rolling bearing device comprising a member and a discharge passage formed in the housing and for sucking and discharging the lubricating oil supplied to the annular space to the outside of the housing, An oil draining member that drains the lubricating oil flowing to at least one of the circumferential axial ends into the discharge path by capillary action is provided , and the oil draining member extends in the radial direction along the end surface of the outer ring. Main unit and Characterized in that characterized in that the radially inner end of said body portion has an extension portion extended into said annular space.

  According to the present invention, since the lubricating oil flowing to the axial end of the inner periphery of the outer ring can be discharged to the discharge path by the oil draining member, from the axial center to the axial end of the inner periphery of the outer ring under high speed rotation. The flowing lubricating oil can be effectively discharged to the discharge path. In addition, since the lubricating oil flowing to the axial end is sucked into the oil draining member by capillary action, the lubricating oil sucked into the oil draining member is prevented from flowing back toward the axial center of the inner periphery of the outer ring. Can do. Accordingly, it is possible to reduce the agitation resistance of the lubricating oil with respect to the rolling elements that are rolling under high-speed rotation, thereby reducing the loss of bearing torque.

In addition, the oil drain member includes a body portion extending radially along the end face of the outer ring, since it has an extension portion extended into said annular space from the radially inner end of said body portion, Since the amount of the lubricating oil sucked in can be increased by the extension portion extended from the main body portion into the annular space, the lubricating oil discharging efficiency by the oil discharging member can be further increased.

  Moreover, it is preferable that the said extension part is extended along the edge part of the said outer ring | wheel inner peripheral surface. In this case, since the lubricating oil flowing from the axial center of the inner circumference of the outer ring to the axial end can be efficiently sucked by the extension, the lubricating oil discharging efficiency by the oil discharging member can be further increased.

  Moreover, it is preferable that the said extension part is cyclically | annularly formed along the circumferential direction of the outer periphery of the said outer ring | wheel. In this case, since the lubricating oil staying over the entire inner circumference of the outer ring can be sucked in by the extension portion, the lubricating oil discharging efficiency by the oil discharging member can be further increased.

In the rolling bearing device, it is preferable that the oil supply member has a supply nozzle that supplies lubricating oil together with compressed air from the outside in the axial direction of the annular space into the annular space.
In this case, since the lubricating oil is supplied together with the compressed air from the outside in the axial direction of the annular space, the lubricating oil can be reliably supplied to the annular space even under high speed rotation. Therefore, even if the lubricating oil in the annular space is discharged to the discharge path by the oil draining member, it is possible to prevent seizure of the rolling bearing due to insufficient lubrication.

  According to the rolling bearing device of the present invention, it is possible to reduce the agitation resistance of the lubricating oil with respect to the rolling elements that are rolling under high-speed rotation, thereby reducing the bearing torque loss.

It is sectional drawing which shows the rolling bearing apparatus which concerns on one Embodiment of this invention. It is a principal part expanded sectional view of FIG. 1 which shows the supply side of the lubricating oil in an oil air lubrication system. FIG. 2 is an enlarged cross-sectional view of a main part of FIG. 1 showing a lubricating oil discharge side in an oil-air lubrication system.

  Hereinafter, embodiments of a rolling bearing device of the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of a rolling bearing device according to an embodiment of the present invention. The rolling bearing device 1 includes a rolling bearing 2 that supports a spindle (not shown) of a machine tool, a housing 3 that holds the rolling bearing 2, and oil and air (supplied together with compressed air) to the rolling bearing 2 by an oil-air lubrication method. An outer ring spacer 5 serving also as an oil supply member for supplying the lubricant, and a discharge passage 8 for discharging the lubricant supplied to the rolling bearing 2 to the outside of the housing 3.

  The rolling bearing 2 includes an inner ring 21 that is externally fitted and fixed to the main shaft, an outer ring 22 that is internally fitted to the housing 3, and a plurality of balls (rolling elements) 23 that roll between the inner ring 21 and the outer ring 22. It is an angular ball bearing comprised with the holder | retainer 24 for hold | maintaining each ball | bowl 23 at equal intervals along the circumferential direction. The inner ring 21, the outer ring 22 and the ball 23 are made of bearing steel such as bearing steel or carburized steel, and the cage 24 is made of synthetic resin such as phenol resin.

  The inner ring 21 has an inner ring raceway surface 21a formed at the axially central portion of the outer periphery thereof. An inner spacer 4 formed in an annular shape is provided adjacent to one side in the axial direction of the inner ring 21 (left side in FIG. 1), and the axial position of the inner ring 21 is set by the inner spacer 4. Yes. Hereinafter, the left side in each drawing of the present embodiment is referred to as “one axial side”, and the right side is referred to as “the other axial direction”.

  The outer ring 22 is disposed concentrically with the inner ring 21 and has an outer ring raceway surface 22a formed at the axially central portion of the inner periphery thereof. The plurality of balls 23 are arranged between the inner ring raceway surface 21a and the outer ring raceway surface 22a so as to roll.

  The cage 24 includes a pair of annular portions 24a and 24b that are spaced apart in the axial direction, and are arranged at equal intervals along the circumferential direction of the annular portions 24a and 24b. And a plurality of column portions 24c connecting the 24b. A pocket 24d is formed between the pair of annular portions 24a, 24b and the adjacent column portion 24c. Each ball 23 is disposed in the pocket 24d, and the balls 23 are arranged along the circumferential direction. It is held at a predetermined interval.

  The outer ring spacer 5 is provided adjacent to one side in the axial direction of the outer ring 22, and the axial position of the outer ring 22 is set by the outer spacer 5. The outer diameter of the outer ring spacer 5 is the same as the outer diameter of the outer ring 22, and the inner diameter of the outer ring spacer 5 is smaller than the inner diameter of the outer ring 22. Thereby, the outer ring spacer 5 is formed thicker than the outer ring 22.

  FIG. 2 is an enlarged cross-sectional view of the main part of FIG. 1 showing the oil / air supply side in the oil / air lubrication system. A supply hole 6 for supplying oil air to the annular space S between the outer periphery of the inner ring 21 and the inner periphery of the outer ring 22 is formed at a predetermined position in the circumferential direction of the outer spacer 5. In the supply hole 6, a concave groove 6 a opened in the outer peripheral portion of the outer spacer 5 is formed over the entire circumference in the circumferential direction.

  Further, the supply hole 6 includes a first hole 6b extending radially inward from the groove 6a, a second hole 6c extending from the radial center of the first hole 6b to the other axial side, The third hole portion 6d extends from the radially inner end of the first hole portion 6b so as to be inclined toward the other axial side and the inner ring 21 side. The second hole portion 6 c and the third hole portion 6 d are formed to have a smaller diameter than the first hole portion 6 b, and the end portion on the other side in the axial direction opens to the end surface 5 a of the outer spacer 5. Thus, the second hole 6c and the third hole 6d function as a supply nozzle P that supplies oil air from the outside in the axial direction of the annular space S into the annular space S.

  A supply passage 3a penetrating in the radial direction is formed in the housing 3 facing the concave groove 6a of the outer spacer 5, and oil-air lubrication disposed outside the housing 3 is provided on the outer peripheral side of the supply passage 3a. A type of fueling device (not shown) is connected. As shown by the arrow A in FIG. 2, the oil air supplied by the oil supply device flows into the first hole 6b from the groove 6a via the supply path 3a, and the second hole 6c and the third hole 6d. Is supplied to the annular space S from the opening. The oil supply device may be disposed inside the housing 3.

  FIG. 3 is an enlarged cross-sectional view of the main part of FIG. 1 showing the oil-air discharge side in the oil-air lubrication system. Between the end surface 22b of the outer ring 22 and the end surface 5a of the outer spacer 5, a discharge hole 7 for discharging the lubricating oil in the oil air supplied to the annular space S to the discharge passage 8 is spaced in the circumferential direction. Are formed. FIG. 3 shows only one discharge hole 7. The discharge hole 7 is formed to extend in the radial direction, and its radially inner end communicates with the annular space S and its radially outer end communicates with the discharge path 8 formed in the housing 3.

  The discharge path 8 is for sucking the lubricating oil supplied to the annular space S and discharging it to the outside of the housing 3. The main path 8a extending in the axial direction, and radially inward from the main path 8a. It has a pair of extending branch paths 8b, 8c. Compressed air flows in the main path 8a in the direction of arrow B in FIG. 3, and the inside of the branch path 8b has a negative pressure. The branch path 8 b is formed such that its radially inner end faces the radially outer end of the discharge hole 7, and the branch path 8 c has its radially inner end on the other axial side of the end face 22 c of the outer ring 22. It is formed to be adjacent to.

  The rolling bearing device 1 further includes a felt 9 that is an oil discharge member that discharges lubricating oil guided to one end in the axial direction of the inner circumference of the outer ring 22 to the discharge path 8 by capillary action. 9 has a main body portion 9a extending in the radial direction along the end face 22a of the outer ring 22 in the discharge hole 7, and an extension portion 9b extending into the annular space S from the radial inner end of the main body portion 9a. ing. The main body 9 a is formed of a string-like member having the same diameter as that of the discharge hole 7, and extends in the radial direction along the end surface 22 b of the outer ring 22 and the end surface 5 a of the outer spacer 5. The radially outer end of the main body 9 a is located at the radially inner end of the branch path 8 b of the discharge path 8.

  The extension portion 9b extends in the axial direction along the end portion of the inner peripheral surface of the outer ring 22 from the radial inner end of the main body portion 9a. The end of the extension portion 9b on the other side in the axial direction is disposed close to the annular portion 24a of the cage 24. The extension 9 b is formed in an annular shape along the circumferential direction of the inner peripheral surface of the outer ring 22, and the outer peripheral surface of the extension 9 b is fixed to the inner peripheral surface of the outer ring 22.

  Thereby, of the oil air supplied to the annular space S, the lubricating oil flowing from the outer ring raceway surface 22a to the one side in the axial direction by the centrifugal force accompanying the high-speed rotation of the rolling bearing 2 is as shown by an arrow C in FIG. It is sucked into the extension 9b of the felt 9 by capillary action and moves outward in the radial direction through the main body 9a. Then, the lubricating oil that has moved to the radially outer end of the main body 9 a is sucked into the main path 8 a via the branch path 8 b that is in negative pressure, and is discharged to the outside of the housing 3.

  Also, of the oil air supplied to the annular space S, the lubricating oil that flows from the outer ring raceway surface 22a to the other side in the axial direction due to the centrifugal force accompanying the high speed rotation of the rolling bearing 2 is shown in FIG. Flows radially outward through the end face 22c of 22. The lubricating oil that has moved to the radially outer end of the end face 22c is sucked together with the compressed air in the oil air into the main path 8a via the branch path 8c that is in negative pressure, and is discharged to the outside of the housing 3. The

  As described above, according to the rolling bearing device 1 according to the embodiment of the present invention, the felt 9 that discharges the lubricating oil in the oil air to the discharge path 8 by the capillary phenomenon is provided on the end surface 22d of the outer ring 22, so that it rotates at high speed. The lubricating oil flowing from the outer ring raceway surface 22a of the outer ring 22 to the end portion on the one axial side in the axial direction can be effectively discharged to the discharge path 8 below. Moreover, since the lubricating oil flowing to the end portion is sucked into the felt 9 by capillary action, it is possible to suppress the lubricating oil sucked into the felt 9 from flowing backward toward the outer ring raceway surface 22a. Accordingly, it is possible to reduce the agitation resistance of the lubricating oil with respect to the balls 23 that are rolling under high-speed rotation, thereby reducing the loss of bearing torque.

Further, since the amount of the lubricating oil sucked in can be increased by the extension 9b extended from the main body 9a of the felt 9 into the annular space S, the lubricating oil discharging efficiency by the felt 9 can be further increased.
Further, since the extension portion 9b extends along the end portion on the one axial side of the inner peripheral surface of the outer ring 22, lubricating oil flowing from the outer ring raceway surface 22a of the outer ring 22 to the one axial side is caused by the extension portion 9b. You can inhale efficiently. Therefore, the lubricating oil discharge efficiency by the felt 9 can be further increased.

  Further, since the extension portion 9b is formed in an annular shape along the circumferential direction of the inner peripheral surface of the outer ring 22, the lubricating oil can be efficiently sucked by the extension portion 9b over the entire circumference of the inner peripheral surface of the outer ring 22. . Therefore, the lubricating oil discharge efficiency by the felt 9 can be further increased.

  Further, in order to supply the lubricating oil together with the compressed air from the openings of the second hole portion 6c and the third hole portion 6d formed in the outer spacer 5, from the axially outer side of the annular space S toward the annular space S. Lubricating oil can be supplied. As a result, since the lubricating oil can be reliably supplied to the annular space S even under high-speed rotation, even if the lubricating oil in the annular space S is discharged to the discharge path 8 by the felt 9, rolling due to insufficient lubrication. The seizure of the bearing 2 can be prevented.

  The present invention is not limited to the above-described embodiment, and can be implemented with appropriate modifications. For example, in this embodiment, felt is used as the oil draining member, but any other string member or metallic mesh member can be used as long as it can suck the lubricating oil by capillary action. Moreover, in this embodiment, although the extension part of the felt is extended in the axial direction, if it is in the annular space S, it should just be extended in arbitrary directions.

  Furthermore, although the felt extension is formed over the entire circumference of the inner peripheral surface of the outer ring, it may be formed at least at a location where the lubricating oil tends to stay. Further, the felt is provided only on one side in the axial direction of the outer ring, but may be provided only on the other side in the axial direction of the outer ring or on both sides in the axial direction.

  Moreover, although the discharge hole 7 of this embodiment is formed between the end surface 22b of the outer ring 22 and the end surface 5a of the outer spacer 5, the end of the outer ring 22 on one axial side or the outer spacer 5 is provided. A through-hole extending in the radial direction may be formed at the end portion on the other side in the axial direction.

  Moreover, in this embodiment, although the angular ball bearing was illustrated as a rolling bearing, a cylindrical roller bearing and a tapered roller bearing may be sufficient. Moreover, although the rolling bearing apparatus of this embodiment was illustrated about the case where it uses for a machine tool, if it is an apparatus by which high-speed rotation performance is requested | required, it can apply suitably.

  DESCRIPTION OF SYMBOLS 1: Rolling bearing apparatus, 2: Rolling bearing, 3: Housing, 5: Outer spacer (oil supply member), 8: Discharge path, 9: Felt (oil discharge member), 9a: Main-body part, 9b: Extension part, 21 : Inner ring, 21a: inner ring raceway surface, 22: outer ring, 22a: outer ring raceway surface, 23: ball (rolling element), P: supply nozzle, S: annular space

Claims (4)

A rolling bearing having an inner ring having an annular inner ring raceway surface on the outer periphery, an outer ring having an annular outer ring raceway surface on the inner periphery, and a plurality of rolling elements rolling between the inner ring raceway surface and the outer ring raceway surface. When,
A housing in which the outer ring is fitted;
An oil supply member that supplies lubricating oil together with compressed air to an annular space between the inner ring outer periphery and the outer ring inner periphery;
An oil-air lubrication type rolling bearing device comprising a discharge passage formed in the housing and sucking and discharging the lubricant supplied to the annular space to the outside of the housing;
An oil drainage member that drains the lubricating oil flowing to at least one of the axial ends of the inner circumference of the outer ring to the discharge path by capillary action ;
The oil draining member has a main body portion extending in a radial direction along an end surface of the outer ring, and an extension portion extended into the annular space from a radial inner end of the main body portion. Rolling bearing device. The rolling bearing device according to claim 1 , wherein the extension portion extends along an end portion of the inner peripheral surface of the outer ring. The rolling bearing device according to claim 2 , wherein the extension portion is formed in an annular shape along a circumferential direction of the inner periphery of the outer ring. The oil supply member, the direction from an axially outer annular space within the annular space, the rolling bearing device according to any one of claims 1 to 3, having a supply nozzle for supplying a lubricating oil with compressed air.

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