JP2013231493A - Angular ball bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an angular ball bearing equipped with a retainer which can prolong a grease life, by stabilizing an amount of grease supplied to a rolling contact surface from the retainer.SOLUTION: In an angular ball bearing 10 being grease-lubricated, a retainer 20 has a convex portion 24 whose inner diameter is smaller than a pitch circle diameter PCD of a ball 13, in a radial direction inside and an axial direction center portion. In a cross section shape of the retainer 20, an axial direction distance A from the axial direction center portion of the retainer 20 to an uprise starting point 24a of the convex portion 24 is larger than an axial direction distance A' from a perpendicular line to a bearing rotation axis from the center point of the ball 13, to a position of a contact angle line L of the ball 13 in a radial direction position of the uprise starting point 24a.

Description

  The present invention relates to an angular ball bearing, and more particularly to an angular ball bearing applied to railways, aviation, general industrial machines, automobiles, and the like including a spindle for machine tools and a ball screw shaft end support.

  Currently, various lubrication methods are used for rolling bearings. Above all, grease lubrication does not require maintenance and does not require an external device, so it is very inexpensive and is used in many situations.

  In general, grease lubrication cannot be replenished from the outside unless the machine is disassembled. Therefore, it is always a problem how to extend the grease life by the initially charged grease.

  Grease deteriorates due to heat generation and wear (rolling contact surface (rolling surface) and sliding contact surface with time and wear over time) of the bearing, and its lubricating performance gradually decreases. Therefore, in order to extend the grease life, it is important to suppress the heat generation and wear of the bearing as much as possible.

  In order to suppress heat generation and wear in lubrication of rolling bearings, it is necessary to always supply an appropriate amount to the rolling surface. When the supply amount of the lubricating oil is large, heat is generated due to the stirring resistance of the lubricating oil, and when it is small, an oil film is not formed on the rolling surface, metal contact occurs, and wear and heat are generated. In particular, grease lubrication has lower fluidity than oil lubrication, so the amount of lubricant supplied to the rolling surface is not stable, and bearing wear and heat generation are likely to occur.

  In addition, during operation of the bearing, the encapsulated grease accumulates on the bearing ring and cage of the bearing, but the location and amount of accumulation are random depending on the shape of the grease, and the lubricating oil on the rolling surface This is one reason why the supply is not stable.

  In Patent Documents 1 and 2, it is devised to improve the lubrication performance of grease-lubricated rolling bearings by depositing grease on the cage. In the solid roller cage of the cylindrical roller bearing described in Patent Document 1, a circumferential groove serving as a grease reservoir is formed on the inner circumferential surface of the cage pocket so that the roller end surface slides between the roller end surface and the bearing ring collar or the cage. The improvement of the lubrication performance in the contact part is aimed at. Further, in the rolling bearing cage described in Patent Document 2, on the inner circumferential surface of the cage pocket, the inner diameter of the end inner circumferential surface portion is set to be smaller than the inner diameter of the central inner circumferential surface portion. A lot of grease is deposited in the vicinity of the moving body to improve the reliability of lubrication in high-speed applications.

Japanese Utility Model Publication No. 5-30554 JP 2006-329218 A

  By the way, in the cylindrical roller bearing described in Patent Document 1, in the grease accumulated on the inner peripheral surface of the cage, the amount of grease supplied to the sliding contact portion between the roller end surface and the race ring collar portion or the cage is increased. Therefore, no consideration is given to the amount of grease supplied to the rolling element rolling surface of the grease.

  Further, in the rolling bearing cage described in Patent Document 2, the purpose is to accumulate more grease at the center of the inner peripheral surface of the cage and extend the life of the grease, and the amount of grease that can be accumulated increases. However, at the same time, the amount of grease supplied to the rolling elements becomes excessive, which may cause abnormal heat generation and shorten the grease life.

  The present invention has been made in view of the above-described problems, and its purpose is to focus on the grease accumulated in the cage, stabilize the amount of grease supplied from the cage to the rolling surface, and extend the life of the grease. SUMMARY OF THE INVENTION An object of the present invention is to provide an angular contact ball bearing having a cage capable of performing the above-described operation.

The above object of the present invention can be achieved by the following constitution.
(1) an outer ring having an outer ring raceway surface on the inner circumferential surface;
An inner ring having an inner ring raceway surface on the outer peripheral surface;
A plurality of balls arranged with a contact angle between the outer ring raceway surface and the inner ring raceway surface;
A cage having a plurality of pockets each holding the plurality of balls;
An angular contact ball bearing that is grease lubricated,
The retainer has a convex portion whose inner diameter is smaller than the pitch circle diameter of the balls at the radially inner side and the axially central portion.
In the cross-sectional shape of the cage, the axial distance from the axial center position of the cage to the rising start point of the convex portion is from the perpendicular from the ball center point to the bearing rotation shaft. An angular ball bearing characterized by being larger than an axial distance to a position of a contact angle line of the ball at a radial position of a starting point.
(2) In the cross-sectional shape of the cage, the axial distance from the axial center position of the cage to the rising start point of the convex portion is from a perpendicular from the center point of the ball to the bearing rotation shaft. The angular ball bearing according to (1), wherein the angular ball bearing is larger than an axial distance to an intersection of a radial position of the rising start point and an end line of the ball rolling surface on the rising start point side.
(3) The outer diameter of the outer diameter portion that intersects the wall surface of the pocket and the inner diameter of the inner diameter portion that intersects the wall surface of the pocket is smaller than the pitch circle diameter of the ball at the axial center position of the cage. The angular ball bearing according to (1) or (2), wherein is larger than a pitch circle diameter of the balls.
(4) an outer ring having an outer ring raceway surface on the inner peripheral surface;
An inner ring having an inner ring raceway surface on the outer peripheral surface;
A plurality of balls arranged with a contact angle between the outer ring raceway surface and the inner ring raceway surface;
A cage having a plurality of pockets each holding the plurality of balls;
An angular contact ball bearing that is grease lubricated,
The retainer is formed in a radially inner side and an axially central portion, and has a convex portion having an inner diameter smaller than a pitch circle diameter of the balls, a radially inner side of the retainer, and an axis of the convex portion. A circumferential groove formed on both sides in the direction,
In the cross-sectional shape of the cage, the axial distance from the axial center position of the cage to the rising start point of the convex portion is from the perpendicular from the ball center point to the bearing rotation shaft. An angular ball bearing characterized by being larger than an axial distance to a position of a contact angle line of the ball at a radial position of a starting point.
(5) In the cross-sectional shape of the cage, the axial distance from the axial center position of the cage to the rising start point of the convex portion is from a perpendicular line from the center point of the ball to the bearing rotation shaft. The angular ball bearing according to (4), wherein the angular ball bearing is larger than an axial distance to an intersection of a radial position of the rising start point and an end line on the rising start side of the rolling surface of the ball.
(6) In the axial center position of the cage, the inner diameter of the inner diameter portion that intersects the wall surface of the pocket is smaller than the pitch circle diameter of the ball, and the outer diameter of the outer diameter portion that intersects the wall surface of the pocket The angular ball bearing according to (4) or (5), wherein is larger than a pitch circle diameter of the balls.

  According to the angular ball bearing of the present invention, a structure having a convex portion on the radially inner side and the axial center portion of the cage is used, and the rising start point of the convex portion is defined in relation to the rolling surface of the ball. With the grease supply position from the cage to the ball as the non-rolling surface, the amount of grease supplied from the cage to the rolling surface can be stabilized and the grease life can be extended.

(A) is sectional drawing of the angular ball bearing which concerns on 1st Embodiment of this invention, (b) is sectional drawing of a holder | retainer. It is sectional drawing along the II line | wire of FIG. In the angular ball bearing of a 1st embodiment, it is a sectional view explaining the more desirable relation between the section shape of a cage and the rolling surface of a ball. (A) is a sectional view showing a state in which grease is deposited on the cage in the angular ball bearing of FIG. 1, and (b) shows a state in which grease is supplied to the ball. It is the figure seen from IV direction. (A) is sectional drawing which shows the state which grease accumulated on the cage | basket in the conventional angular contact ball bearing, (b) is a ball | bowl which shows a mode that grease is supplied to a ball | bowl, (V) of (a). It is the figure seen from the direction. (A) And (b) is sectional drawing of the holder | retainer which shows the modification of 1st Embodiment. It is sectional drawing of the angular ball bearing which concerns on 2nd Embodiment of this invention. (A)-(c) is sectional drawing of the crown type holder | retainer which concerns on the modification of this invention. It is sectional drawing of the angular ball bearing which concerns on the modification of this invention.

(First embodiment)
Hereinafter, an angular contact ball bearing concerning a 1st embodiment of the present invention is explained in detail based on a drawing.

  As shown in FIG. 1, the angular ball bearing 10 of the first embodiment includes an outer ring 11 having an outer ring raceway surface 11a on an inner peripheral surface, an inner ring 12 having an inner ring raceway surface 12a on an outer peripheral surface, and an outer ring raceway surface 11a. A plurality of balls 13 arranged with a contact angle α between the inner ring raceway surface 12a and a ball guide type cage 20 having a plurality of pockets 21 for holding the plurality of balls 13 respectively. The angular ball bearing 10 is used for inner ring rotation and is grease-lubricated by initial sealing.

  The cage 20 is provided at a predetermined interval in the circumferential direction between the pair of annular portions 22 and 22 and the pair of annular portions 22 and 22 at both ends in the axial direction. And a plurality of column portions 23 extending in the axial direction so as to be connected, and are formed symmetrically with respect to the axial center position. The pocket 21 is defined by a pair of annular portions 22 and 22 and adjacent pockets 23 and 23, and is formed in a cylindrical shape.

  The retainer 20 has a pair of protrusions 24 formed on the radially inner side and in the axially central portion, and a pair of grooves formed on the radially inner side of the retainer 20 and on both sides in the axial direction of the protrusion 24. Peripheral groove portions 25, 25. That is, the convex portion 24 protrudes from the groove bottom surface 25 a where the circumferential groove portions 25, 25 of the column portion 23 are formed to the inner diameter side, and is formed in the axial direction central portion of the column portion 23 over the circumferential direction.

  As shown also in FIG. 2, the pocket 21 of the cage 20 is usually designed with a certain gap with respect to the ball 13. At this time, in order to define the gap, the tangent line at the point where the ball 13 and the wall surface of the pocket 21 are in contact with the wall surface of the pocket 21 is parallel. That is, when the ball 13 comes into contact with the wall surface of the pocket 21, it is necessary that the great circle of the ball 13 (maximum diameter portion = equatorial position) is always the contact position. Therefore, the inner diameter d1 of the inner diameter portion that intersects the wall surface of the pocket 21 is smaller than the pitch circle diameter PCD of the ball 13 and the outer diameter portion that intersects the wall surface of the pocket 21 at the axial center position of the cage 20. The diameter d3 needs to be larger than the pitch circle diameter PCD of the balls 13. Therefore, the convex portion 24 has an inner diameter d1 smaller than the pitch circle diameter PCD of the balls 13 (d1 <PCD). Further, since the cage 20 has a movement amount Δd1 (diameter gap) in the radial direction, it is necessary to satisfy d1 (d2) <PCD−Δd1 / 2 and d3> PCD + Δd1 / 2. .

  Further, the grease is basically deposited around a portion having the largest centrifugal force on the inner peripheral surface of the cage 20, that is, a portion having the largest inner diameter. That is, in this embodiment, the grease is accumulated in the circumferential grooves 25 and 25 of the cage 20. Further, the grease accumulated in the circumferential grooves 25, 25 is supplied to the rolling surface through the balls 13 by coming into contact with the balls 13 by the flow due to the centrifugal force.

  At this time, if grease is directly supplied onto the circumference of the ball 13 which is the rolling surface, the grease is excessively supplied and heat is generated, so that the grease is supplied only to the non-rolling surface of the ball 13. In addition, a boundary between the convex portion 24 and the circumferential groove portions 25, 25, that is, a rising start point 24a of the convex portion 24 is set.

  That is, in the cross-sectional shape of the cage 20, the axial distance A from the axial center position of the cage 20 to the rising start point 24 a of the convex portion 24 is a perpendicular line V from the center point of the ball 13 to the bearing rotation shaft. To an axial distance A ′ to the position of the contact angle line L of the ball 13 at the radial position of the standing start point 24a (A> A ′). The contact angle line L is a line connecting the contact points of the balls 13 with the outer ring raceway surface 11a and the inner ring raceway surface 12a. At this time, assuming that the standing start point 24a (= groove bottom diameter) is d2, A ′ = | (PCD−d2) tan α / 2 |.

  Further, since the contact between the balls 13 and the outer ring raceway surface 11a and the inner ring raceway surface 12a becomes a contact ellipse, the rolling surface necessarily has a width C. For this reason, it is preferable that A> A ″. At this time, A ″ indicates the radial position of the standing start point 24a from the vertical line V from the center point of the ball 13 to the bearing rotation shaft, and the standing start point side end line (groove bottom side end line) of the rolling surface. A ′ = | (PCD−d2) tan α / 2 + C / (2 cos α) |. Thereby, it can supply reliably only by the non-rolling surface of the ball | bowl 13. FIG.

  Note that FIG. 3 shows the retention when the relationship of A, A ′, A ″ is satisfied and the grease adhering to the rising surface of the convex portion 24 is not directly supplied to the rolling surface. An angular ball bearing 10a having the shape of the vessel 20 is shown. In this case, in the cross-sectional shape of the cage 20, the axial distance D from the axial center position of the cage 20 to the standing completion point 24 b of the convex portion 24 is a perpendicular line from the center point of the ball 13 to the bearing rotation shaft. It is preferably set to be larger than the axial distance D ′ from V to the position of the contact angle line L of the ball 13 at the radial position of the standing completion point 24b (tip surface of the convex portion 24) (D > D '). Similarly to the above, when considering the contact ellipse, D ″ represents the radial position of the standing completion point 24b (the tip surface of the convex portion 24) from the perpendicular V from the center point of the ball 13 to the bearing rotation shaft. Further, it is the axial distance to the intersection point q with the rising start point side end line (groove bottom side end line) of the rolling surface, and it is more preferable that D> D ″.

  Moreover, since grease accumulates in the circumferential groove portions 25, 25 of the cage 10, the larger the circumferential groove portions 25, 25, the greater the amount of grease that can be deposited. Specifically, the distance B from the axial center position of the cage 20 to the axially outer groove bottom starting point 25b, and the distance B from the axial center position of the cage 20 to the axial end wall surface of the pocket 21. 'Is preferably B> B'. Thereby, since the area | region corresponding to between B-B 'in the width direction among the circumferential groove parts 25 and 25 becomes a ring, the depositable quantity of grease increases significantly.

  FIG. 4 shows a state where the grease G deposited on the cage 20 is supplied to the balls 13 in the angular ball bearing 10 provided with the cage 20 of the present embodiment, and FIG. 5 has a convex portion and a circumferential groove portion. In the angular ball bearing 10 ′ provided with a standard cage 20 ′ that does not, grease G deposited on the cage 20 ′ is supplied to the balls 13.

  Therefore, as shown in FIG. 5, in the standard cage 20 ′, the grease G is deposited on the entire inner peripheral surface of the cage 20 ′, so that the grease supply position to the balls 13 is random. And when the grease G is directly supplied to the rolling surface of the ball | bowl 13, there exists a possibility of causing the abnormal heat_generation | fever by excessive supply. On the other hand, in the cage 20 of the present embodiment shown in FIG. 4, most of the grease G is deposited on the circumferential groove portions 25, 25 by the convex portion 24 and the circumferential groove portions 25, 25, and therefore only on the non-rolling surface. Grease G is supplied. Then, the grease G supplied to the non-rolling surface spreads toward the rolling surface (ball circumferential speed maximum position) while being stretched by the centrifugal force caused by the rotation of the balls 13. At this time, the diffusion rate of the grease G increases in accordance with the rotation speed of the balls 13, but basically, as the rolling bearing becomes faster, the necessary amount of grease increases, so that an appropriate amount can be easily maintained. Further, since the grease G is supplied to the non-rolling surface, even when intermittently supplied, it is mixed with the grease G that is being diffused after the supply, so that fluctuations in the supply amount to the rolling surface can be suppressed.

  In the above embodiment, the wall surface of the convex portion 24 and the wall surface of the circumferential groove portion 25 are formed so as to be inclined so that the groove width of the circumferential groove portion 25 gradually increases on the inner diameter side. The wall surface and the wall surface of the circumferential groove 25 may be formed perpendicular to the rotation axis as in the modification shown in FIG. 6A, and as in the modification shown in FIG. It may be formed by a curved surface. In other words, the retainer 20 can achieve the above-described effects because the convex portion 24 has the minimum inner diameter of the inner peripheral surface and the peripheral groove portion 25 has the maximum inner diameter of the inner peripheral surface.

(Second Embodiment)
Next, an angular ball bearing 10A according to a second embodiment of the present invention will be described in detail with reference to FIG. Since this embodiment is different from the first embodiment only in the shape of the cage, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted or simplified.

As in the first embodiment, the cage 20a in the second embodiment has a convex portion 24, but does not have a circumferential groove portion on the outer side in the axial direction, and projects from the axial end portion of the cage 20. It is comprised by the internal peripheral surface of uniform internal diameter to the standing start point 24a of the part 24. FIG. Basically, in the inner ring rotary bearing, since grease is deposited on the inner peripheral surface of the cage 20, a sufficient amount of grease can be secured even in a configuration having no peripheral groove. Further, by not having the circumferential groove portion, it is possible to reduce the weight and improve the rigidity of the cage 20 by adjusting the inner diameters at both ends of the cage 20 in the axial direction.
Other configurations and operations are the same as those in the first embodiment.

In addition, this invention is not limited to each embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
For example, the present invention can be applied to a crown type cage as shown in FIG. Because of the structure of the crown-type cage 20b, one of the pockets 21 of the cage 20b needs to be open with respect to the cage axial direction. In the cage of the present invention, if the convex portion 24 having the smallest inner diameter is formed, the effect can be exerted, so that the cage can also be applied to the crown type cage 20b. In the crown-shaped cage 20b, it is preferable that the circumferential groove 25 is formed at both ends of the convex portion 24 as shown in FIG. Even if it has a circumferential groove portion 25 only on one side as shown in b) or a shape without a circumferential groove portion as shown in FIG. 8C, the effect can be sufficiently exerted.

  Further, the guide type of the cage is not limited to the ball guide method of the above embodiment, and may be an outer ring guide method or an inner ring guide method, and the pocket surface is not limited to a cylindrical shape, but a spherical surface of the ball. It may be a shape along. Further, any material can be applied to the material of the cage.

  Further, in the angular ball bearing of the present invention, the outer diameters of the shoulder portions on both sides in the axial direction of the inner ring 12 may be the same size as in the above embodiment, or as shown in FIG. The shoulder may be formed with a small diameter with respect to the other shoulder. In the cross-sectional view of FIG. 1, the inner diameter d1 of the convex portion 24 is shown to be smaller than the outer diameter of the shoulder portion of the inner ring 12, but from the viewpoint of assemblability, the shoulder portion on at least one axial side of the inner ring 12 is shown. The outer diameter needs to be designed smaller than the inner diameter d1 of the convex portion 24.

DESCRIPTION OF SYMBOLS 10, 10A angular contact ball bearing 11 Outer ring 11a Outer ring raceway surface 12 Inner ring 12a Inner ring raceway surface 13 Ball 20, 20a, 20b Cage 21 Pocket 22 Ring portion 23 Column portion 24 Convex portion 25 Circumferential groove portion C Rolling surface

Claims (6)

An outer ring having an outer ring raceway surface on the inner circumferential surface;
An inner ring having an inner ring raceway surface on the outer peripheral surface;
A plurality of balls arranged with a contact angle between the outer ring raceway surface and the inner ring raceway surface;
A cage having a plurality of pockets each holding the plurality of balls;
An angular contact ball bearing that is grease lubricated,
The retainer has a convex portion whose inner diameter is smaller than the pitch circle diameter of the balls at the radially inner side and the axially central portion.
In the cross-sectional shape of the cage, the axial distance from the axial center position of the cage to the rising start point of the convex portion is from the perpendicular from the ball center point to the bearing rotation shaft. An angular ball bearing characterized by being larger than an axial distance to a position of a contact angle line of the ball at a radial position of a starting point.   In the cross-sectional shape of the cage, the axial distance from the axial center position of the cage to the rising start point of the convex portion is from the perpendicular from the ball center point to the bearing rotation shaft. The angular ball bearing according to claim 1, wherein the angular ball bearing is greater than an axial distance to an intersection of a radial position of the starting point and an end line on the rising start side of the ball rolling surface.   The inner diameter of the inner diameter portion intersecting the wall surface of the pocket is smaller than the pitch circle diameter of the ball at the axial center position of the cage, and the outer diameter of the outer diameter portion intersecting the wall surface of the pocket is the ball. The angular ball bearing according to claim 1, wherein the angular ball bearing is larger than a pitch circle diameter. An outer ring having an outer ring raceway surface on the inner circumferential surface;
An inner ring having an inner ring raceway surface on the outer peripheral surface;
A plurality of balls arranged with a contact angle between the outer ring raceway surface and the inner ring raceway surface;
A cage having a plurality of pockets each holding the plurality of balls;
An angular contact ball bearing that is grease lubricated,
The retainer is formed in a radially inner side and an axially central portion, and has a convex portion having an inner diameter smaller than a pitch circle diameter of the balls, a radially inner side of the retainer, and an axis of the convex portion. A circumferential groove formed on both sides in the direction,
In the cross-sectional shape of the cage, the axial distance from the axial center position of the cage to the rising start point of the convex portion is from the perpendicular from the ball center point to the bearing rotation shaft. An angular ball bearing characterized by being larger than an axial distance to a position of a contact angle line of the ball at a radial position of a starting point.   In the cross-sectional shape of the cage, the axial distance from the axial center position of the cage to the rising start point of the convex portion is from the perpendicular from the ball center point to the bearing rotation shaft. The angular ball bearing according to claim 4, wherein the angular ball bearing is larger than an axial distance to an intersection of a radial position of the start point and an end line on the rising start side of the rolling surface of the ball.   The inner diameter of the inner diameter portion intersecting the wall surface of the pocket is smaller than the pitch circle diameter of the ball at the axial center position of the cage, and the outer diameter of the outer diameter portion intersecting the wall surface of the pocket is the ball. The angular ball bearing according to claim 4, wherein the angular ball bearing is larger than a pitch circle diameter.

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