JP2014202253A - Comb-shaped cage for double row roller bearing, and double row roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a comb-shaped cage for a double row roller bearing capable of preventing difficulty in independent rotation caused by contact of back faces, even when deformation by centrifugal force in accompany with rotation, due to different rotating speed in each row, is found.SOLUTION: Two comb-shaped cages 5 and 5 retain a plurality of rollers 4 in each row, and are disposed in a state that back faces 14 and 14 can be kept into contact with each other. A longitudinal cross-section of an annular portion 10 has the circular arc-shape at a radial outer side at a back face 14 side, and a radial inner side of one side face 11 side has the circular arc shape.

Description

  The present invention relates to a comb-type cage incorporated in a double-row roller bearing and a double-row roller bearing provided with a comb-type cage.

  In a machine tool, a bearing portion that rotatably supports a main shaft is required to have high rigidity in order to maintain high machining accuracy. For this reason, a double row roller bearing is used. Further, in recent years, since a high-speed rotation of the main shaft is required, a double-row roller bearing that can cope with high-speed rotation is required.

  As shown in FIG. 6, the double row roller bearing 101 includes an inner ring 102, an outer ring 103, and a plurality of rollers 104 arranged in a double row state between the inner ring 102 and the outer ring 103. And there exists the double row roller bearing 101 provided with the independent holder | retainer 105 which hold | maintains the some roller 104 for every row | line | column (for example, refer patent document 1). That is, two cages 105 and 105 are incorporated in the double row roller bearing 101. Each cage 105 includes an annular portion 110 and a plurality of column portions 120 extending in the axial direction from one side surface 111 of the annular portion 110 and spaced apart in the circumferential direction. It is configured. In each comb-shaped cage, a space between the column portions 120 adjacent in the circumferential direction becomes a pocket for holding the rollers 105. Further, the two comb cages 105 and 105 are incorporated in the bearing 101 so that the one side surface 111 and the back surface 114 which is the opposite surface in the axial direction can contact each other.

  In the case of the comb-shaped cage, since the column part is in the shape of a cantilever projecting in the axial direction from the annular part, the tip part side of the column part can be freely deformed to some extent. For this reason, for example, when the double row roller bearing rotates, the roller advances and lags, so that even if tensile force and compressive force are repeatedly applied to the column portion, the force can be released and damage occurs. Hateful. On the other hand, in the case of a cage-type cage in which a pair of annular parts is connected by a pillar part, the pillar part is fixed to the annular parts on both sides, and deformation is restrained. When a pulling force and a compressive force are repeatedly applied to the column portion, it is difficult to release the force, and damage is likely to occur as compared with a comb-type cage.

JP 2012-102996 A (see FIG. 3)

The rotation speed of the spindle of the machine tool is selected from a low-speed rotation to a high-speed rotation (for example, 15000 rpm), and the spindle rotates at various rotation speeds. And according to the change of the rotation speed of the main shaft, the rotation speed of the double row roller bearing and the comb cage incorporated in this bearing also changes.
In the case of a machine tool, a large radial load acts on the tip end side of the main shaft. On the other hand, the double row roller bearing that supports the main shaft is provided at the base or intermediate portion of the main shaft. As shown, in the double row roller bearing 101, the load acting on one side (left side) roller row is different from the load acting on the other side (right side) roller row. For this reason, the rotational speed of the roller train on one side is slightly different from the rotational speed of the roller train on the other side. As a result, the cage 105 for one side (left side) and the other side (right side) The number of rotations of the roller train cage 105 is also different.

  Furthermore, each of the cages 105 and 105 is deformed by centrifugal force when rotated (especially when rotating at a high speed), but the column part 120 is cantilevered and thus is easily deformed radially outward. Deforms (twist deformation). As described above, the two cages 105 and 105 are incorporated in the bearing 101 so that the back surfaces 114 and 114 can be brought into contact with each other. They contact each other in the form of mutually pushing on the radially outer side.

  The roller train cage 105 on one side and the roller train retainer 105 on the other side rotate at different rotational speeds, and the cages 105 and 105 rotate at a high speed to increase the centrifugal force. In response to this, when the pressing force between the back surfaces 114 and 114 increases, the sliding resistance between the back surfaces 114 and 114 increases. In this case, the two cages 105 and 105 are difficult to rotate independently, and may cause heat generation and wear.

  Therefore, according to the present invention, it is possible to prevent the rotation independently from being difficult due to the contact between the back surfaces even when the number of rotations is different in each row and it is deformed by the centrifugal force accompanying the rotation. It is an object of the present invention to provide a comb cage and a double row roller bearing including such a comb cage.

  The present invention is incorporated in a double row roller bearing in which a plurality of rollers are arranged in a double row state between an inner ring and an outer ring, and is provided so that the plurality of rollers are held for each row and the back surfaces can be contacted. A comb-shaped cage, which is provided with an annular part having an annular back surface, and extending in the axial direction from one side surface opposite to the back surface of the annular part in the axial direction and spaced apart in the circumferential direction. A plurality of pillar portions, and the longitudinal cross-sectional shape of the annular portion is an arc shape on the radially outer side of the back surface side, and an arc shape on the radially inner side of the one side surface side. It is characterized by.

According to the present invention, the comb-type cage for one side of the roller train and the comb-type cage for the other side of the roller train rotate at different rotational speeds, and the entire cage is deformed due to centrifugal force. Even when the (twist deformation) is large and the backs are in contact with each other on the outside in the radial direction, the longitudinal cross-sectional shape of the annular portion of each comb-shaped cage is an arc shape on the outside in the radial direction Therefore, contact can be made at this arc-shaped portion. For this reason, the contact area between the back surfaces can be reduced, the sliding resistance between the back surfaces can be prevented from increasing, and each comb-shaped cage can easily rotate independently.
Further, when the annular portion is deformed (twisted deformation) due to the deformation of the entire cage, the radially inner side may come into contact with the end surface of the roller on one side surface side. However, since the radially inner side of the one side surface has an arc shape, contact with the end surface of the roller can be prevented.

  In addition, the longitudinal cross-sectional shape of the annular portion is preferably a circle, an ellipse, or an oval, and thus, with respect to the longitudinal cross-sectional shape of the annular portion, the radially outer side of the back side is an arc shape, and The inner side in the radial direction of the one side can be formed into an arc shape.

Moreover, it is preferable that the centroid position of the longitudinal cross-section in the part containing the said annular part and the said column part exists in the range of the longitudinal cross-section of the said annular part.
The deformation in the portion including the annular portion and the column portion is approximately torsional deformation around the centroid of the longitudinal section in the portion. Therefore, the center of torsional deformation can be made as close as possible to the center of the longitudinal section of only the annular portion by making the centroid position of the longitudinal section be within the range of the longitudinal section of the annular portion. For this reason, it becomes easy to displace the annular part around the center of the longitudinal section of the annular part by torsional deformation, and thereby the two comb-shaped cages are in contact with each other in the arc shape of the annular part.

  The present invention also includes an inner ring, an outer ring, a plurality of rollers arranged in a double row between the inner ring and the outer ring, and two independent cages that hold the plurality of rollers for each row. Each of the cages is provided with an annular portion having an annular back surface, and an axial portion extending from one side surface opposite to the back surface of the annular portion in the axial direction and spaced apart in the circumferential direction. A plurality of pillar parts, and a comb-shaped cage provided so that the back surfaces can be in contact with each other, and the longitudinal cross-sectional shape of the annular part is an arc shape on the radially outer side of the back side In addition, the radially inner side of the one side surface has an arc shape.

According to the present invention, the comb-type cage for one side of the roller train and the comb-type cage for the other side of the roller train rotate at different rotational speeds, and the entire cage is deformed due to centrifugal force. Even when the (twist deformation) is large and the backs are in contact with each other on the outside in the radial direction, the longitudinal cross-sectional shape of the annular portion of each comb-shaped cage is an arc shape on the outside in the radial direction Therefore, contact can be made at this arc-shaped portion. For this reason, the contact area between the back surfaces can be reduced, the sliding resistance between the back surfaces can be prevented from increasing, and each comb-shaped cage can easily rotate independently.
Further, when the annular portion is deformed (twisted deformation) due to the deformation of the entire cage, the radially inner side may come into contact with the end surface of the roller on one side surface side. However, since the radially inner side of the one side surface has an arc shape, contact with the end surface of the roller can be prevented.

  According to the comb cage of the present invention and the double row roller bearing provided with the comb cage, when the two comb cages try to contact each other on the outer side in the radial direction between the back surfaces, an arc-shaped portion Therefore, the contact area between the back surfaces can be reduced, and the sliding resistance between the back surfaces can be prevented from increasing. As a result, each of the comb cages can be easily rotated independently.

It is a longitudinal cross-sectional view of a double row roller bearing. It is a perspective view of a holder | retainer. It is sectional drawing of two holders. It is sectional drawing which shows typically the holder | retainer deform | transformed with the centrifugal force. It is a longitudinal cross-sectional view in the part containing the annular part and pillar part of a holder | retainer. It is a longitudinal cross-sectional view of the double row roller bearing provided with the conventional comb-shaped cage.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a double row roller bearing 1. In addition, in each drawing, the same code | symbol (reference number) is attached | subjected to the same component, and the overlapping description is abbreviate | omitted.

The double row roller bearing 1 is used as a bearing for supporting a main shaft 6 of a machine tool such as a general-purpose lathe, CNC lathe, machining center, or milling machine, and can support the main shaft 6 rotating at high speed with high rigidity. .
The diameter of the main shaft 6 is, for example, about 50 to 150 mm, and the maximum rotation speed of the main shaft 6 is 10,000 to 15000 rpm. The spindle 6 may rotate at a low speed or may rotate at a high speed, and accelerates rapidly from a low speed or stopped state to a high speed rotation state (maximum rotation speed).

  The double row roller bearing 1 of this embodiment includes an inner ring 2, an outer ring 3, a plurality of rollers 4 disposed between the inner ring 2 and the outer ring 3, and an annular cage 5 that holds the rollers 4. And 5. The rollers 4 are arranged in a double row state (double row state), and each of the cages 5 and 5 holds a plurality of rollers 4 independently for each row. That is, two independent cages 5 and 5 are incorporated in the double row roller bearing 1. The outer peripheral surface of the roller 4 is cylindrical, and the double row roller bearing 1 is a double row cylindrical roller bearing.

  On the outer peripheral surface of the inner ring 2, there are formed rolling surfaces 2a and 2b on which the rollers 4 arranged in two rows roll. A part of the inner peripheral surface of the outer ring 3 is formed by rolling the two rows of rollers 4. It becomes the rolling surfaces 3a and 3b which move. The outer ring 3 is attached to the inner peripheral surface of the bearing housing 8 of the machine tool, and the main shaft 6 is inserted into the inner ring 2. The double row roller bearing 1 is grease-lubricated, and grease is adhered to the inner ring 2, the outer ring 3, the roller 4 and the cage 5.

  The roller train cage 5 on the one side and the roller train retainer 5 on the other side are the same, although the mounting direction to the double row roller bearing 1 is different. These cages 5 and 5 are incorporated in the double row roller bearing 1 side by side in the axial direction, and one side surface 11 facing the axial direction of each cage 5 faces the outside in the axial direction of the double row roller bearing 1. It arrange | positions and the cyclic | annular back surfaces 14 and 14 which the holder | retainers 5 and 5 oppose can contact. And each of the holder | retainers 5 and 5 can rotate with each roller row independently.

  FIG. 2 is a perspective view of the cage 5 (the cage 5 on the right side in FIG. 1). The cage 5 is a comb cage, and includes an annular portion 10 having a ring shape and a plurality of column portions 20. The plurality of column portions 20 are provided at intervals (equal intervals) in the circumferential direction, and each column portion 20 is formed to extend in the axial direction from one side surface 11 of the annular portion 10. For this reason, the column portion 20 has a cantilever shape protruding from the annular portion 10. In addition, the surface (other side surface) opposite to the axial direction of the one side surface 11 is the back surface 14. As will be described later, the back surface 14 is configured by an annular curved surface (see FIG. 3), and becomes a mating surface that can come into contact with the back surface 14 of another cage 5 installed adjacent to the axial direction.

  The cage 5 is made of resin (synthetic resin), is manufactured by injection molding, and the annular portion 10 and the column portion 20 are integrally molded. The material of the cage 5 can be, for example, polyetheretherketone (PEEK) or polyamide.

  The column portions 20 are provided at regular intervals in the circumferential direction, and pockets 7 for holding the rollers are formed between the column portions 20 and 20 on the one side surface 11 side of the annular portion 10 and adjacent in the circumferential direction. Yes. That is, each pocket 7 includes a space surrounded by the opposing surfaces 24 and 24 of the column portions 20 and 20 that are adjacent to each other in the circumferential direction and the one side surface 11 of the annular portion 10. Each pocket 7 is open toward the outside in the axial direction, and the cage 5 has a comb-like shape as a whole.

FIG. 3 is a cross-sectional view of the two cages 5 and 5. As shown in FIG. 3, the longitudinal cross-sectional shape of the annular portion 10 is a circle. In addition, a vertical cross section is a cross section at the time of cut | disconnecting by the plane containing the centerline of the axial direction of the holder | retainer 5. FIG. In each of the two cages 5 and 5, the annular portion 10 has a circular longitudinal cross-sectional shape, and therefore, in the longitudinal cross section of the annular portion 10, a radially outer portion E1 _o on the side surface 11 side. The radially inner portion E1 _i has an arc shape, and the radially outer portion E2 _o and the radially inner portion E2 _i on the back surface 14 side have an arc shape. These arc shapes are shapes centered on the center Co of the annular portion 10.

When the cage 5 is viewed from one side in the axial direction (column side), the visible range is the one side surface 11 and the invisible range is the back surface 14. Further, in each of the one side surface 11 and the back surface 14, the radially outer range from the center Co of the annular portion 10 is the radially outer portion (E1 _o , E2 _o ), and the radial direction from the center Co. The inner range is the radially inner portion (E1 _i , E2 _i ).

  FIG. 5 is a longitudinal sectional view of a portion P including the annular portion 10 and the column portion 20 in the cage 5. The position of the centroid G of the longitudinal section in the portion P including the annular portion 10 and the column portion 20 exists within the range of the longitudinal section of the annular portion 10 (only). In FIG. 5, the range of the longitudinal section of the annular portion 10 is indicated by hatching. FIG. 5 shows a state before “deformation” described next.

In the machine tool in which the double row roller bearing 1 of the present embodiment is used, the main shaft 6 (see FIG. 1) rotates at various rotational speeds from a low speed to a high speed (for example, 15000 rpm). And according to the change of the rotation speed of this main shaft 6, the rotation speed of the double row roller bearing 1 and the cages 5 and 5 incorporated in this bearing 1 also changes.
The cage 5 is elastically deformed radially outward by the centrifugal force by rotating. However, when the rotational speed is increased, the centrifugal force acting on the cage 5 is increased, and the column portion 20 is deformed radially outward. To do. In particular, since the column portion 20 has a cantilever shape, the column portion 20 is easily deformed radially outward.

  As a result, the annular portion 10 that is continuous with the plurality of column portions 20 to be deformed outward in the radial direction is affected by the column portions 20, and the center Co of the annular portion 10 as shown in FIG. Displaces around the side point (virtual point). That is, the torsional deformation around the virtual point occurs in the annular portion 10. FIG. 4 is a cross-sectional view schematically showing the cages 5 and 5 deformed by centrifugal force. In this figure, the column portion 20 is larger than the actual size outward in order to facilitate the explanation. A deformed state is shown.

  Further, in the case of a machine tool, a cutting tool or the like is attached to the tip end side of the main shaft 6 and a large radial load acts on the tip end side, whereas the double row roller bearing 1 that supports the main shaft 6 is It is provided at the base or intermediate part of the main shaft 6. For this reason, in the double row roller bearing 1 shown in FIG. 1, the load acting on one side (left side) roller row and the load acting on the other side (right side) roller row are different, and one side roller row ( The number of rotations on the left side and the number of rotations on the other side (right side) are slightly different. As a result, the number of rotations of the roller train cage 5 on one side (left side) and the roller train cage 5 on the other side (right side) are also different.

  And when these cages 5 and 5 rotate (especially when rotating at high speed), they are deformed by the centrifugal force as described above, but the column part 20 is cantilevered and thus is easily deformed radially outward. The annular portion 10 integrated with the plurality of column portions 20 is also deformed (twisted). Since the two cages 5 and 5 are incorporated in the bearing 1 so that the back surfaces 14 and 14 can be brought into contact with each other, the back surfaces 14 are in the radially outer portion by the deformation (twist deformation). Try to touch each other.

  In the case of the conventional cage 105 shown in FIG. 6, the one side (left side) roller train cage 105 and the other side (right side) roller train cage 105 rotate at different rotational speeds. In addition, when the cages 105 and 105 rotate at a high speed and the centrifugal force increases, and the pressing force at the radially outer portion of the back surfaces 114 and 114 increases due to the torsional deformation, the sliding between the back surfaces 114 and 114 occurs. Dynamic resistance increases. In this case, each of the cages 105 and 105 is difficult to rotate independently, and may cause heat generation and wear.

However, according to the cage 5 (see FIG. 1) of the present embodiment, the number of rotations differs between the roller train cage 5 on one side (left side) and the roller train cage 5 on the other side (right side). In addition, the overall deformation (torsional deformation) of each cage 5 due to centrifugal force increases, and the back surfaces 14 and 14 contact each other at their radially outer portions E1 _o and E2 _o (see FIG. 4). Even in this case, the circular cross section of the annular portion 10 is in contact with the arc-shaped portion E2 _o because the radially outer portion E2 _o of the back surface 14 side has an arc shape. For this reason, the contact area between the back surfaces 14 and 14 can be reduced, the sliding resistance between the back surfaces 14 and 14 is prevented from increasing, and the cages 5 and 5 are each easily rotated independently.

Further, in FIG. 5, the deformation in the portion P including the annular portion 10 and the column portion 20 due to the centrifugal force is approximately centered on the position of the centroid G (see FIG. 5) of the longitudinal section in this portion P. Torsional deformation. Therefore, by making the position of the centroid G within the range of the longitudinal section of the annular portion 10, the center of torsional deformation can be as close as possible to the center Co of the longitudinal section of only the annular portion 10. . As a result, as shown in FIG. 4, it becomes easy to displace the annular portion 10 around the center Co of the longitudinal section of the annular portion 10 due to torsional deformation, whereby the two cages 5, 5 are connected to the annular portion. Ten arc-shaped portions E2 _o and E2 _o are in contact with each other, and the contact surface pressure can be reduced.

Further, a gap d is provided between the end surface 4a of the roller 4 held in the pocket of each cage 5 and one side surface 11 of the cage 5 so that the roller 4 can freely rotate. (See FIGS. 3 and 4).
In the case of the conventional cage 105 shown in FIG. 6, if the annular portion 110 of each cage 105 is torsionally deformed as described above, the radially inner side on the side surface 111 may come into contact with the end surface 104 a of the roller 104. . In this case, resistance is given to the roller 104, and the rotational performance of the double row roller bearing 101 is deteriorated.

However, in the case of the cage 5 of the present embodiment (see FIGS. 3 and 4), the longitudinal cross-sectional shape of the annular portion 10 is an arc shape on the radially outer side (E2 _o ) of the back surface 14 side as described above. In addition, the radially inner side (E1 _i ) of the side surface 11 side is also arc-shaped.
For this reason, even if the annular portion 110 of each cage 5 is torsionally deformed around a point on the center Co side of the annular portion 10, it is possible to prevent the one side surface 11 from coming into contact with the end surface 4 a of the roller 4. It becomes possible.

  As described above, each of the two cages 5 and 5 easily rotates independently, suppresses the resistance applied to the rollers 4, and becomes the double row roller bearing 1 suitable for high speed rotation.

Further, since the cage 5 of the present embodiment is made of resin, the rotational resistance can be made smaller than that made of metal (for example, made of brass), the noise is low, and high-speed rotation performance is high.
The cage is made of brass (made of copper alloy), but when used in a high-speed rotation environment, the inner circumferential surface, outer circumferential surface, pocket surface, etc. of the cage are located on the inner ring, outer ring and rollers. Abrasion occurs due to contact and generates abrasion powder. If this wear powder is mixed in the grease for lubricating a double row roller bearing, the lubrication performance of the grease is deteriorated, and there is a possibility of causing seizure or damage of the bearing. However, since the cage 5 of the present embodiment is made of resin, it is possible to prevent the grease lubrication performance from being deteriorated due to the wear powder as described above. That is, the resin cage 5 is suitable for high speed rotation as compared with a brass cage.

  Further, since the cage 5 has a comb shape and the column portion 20 has a cantilever shape protruding in the axial direction from the annular portion 10, the front side of the column portion 20 can be freely deformed to some extent. For this reason, even if the double row roller bearing 1 rotates and the tensile force and the compressive force are repeatedly applied to the cage 5 due to the advance and delay of the roller 4, the force can be released and the breakage hardly occurs.

Moreover, the double row roller bearing and the cage of the present invention are not limited to the illustrated form, and may be in other forms within the scope of the present invention. For example, in the above-described embodiment, the vertical cross-sectional shape of the annular portion 10 is a circular shape having one radius, but other shapes may be used, and the vertical cross-sectional shape of the annular portion 10 may be an ellipse or an ellipse. It may be. In this case, in the longitudinal section, an ellipse or an ellipse whose longitudinal direction is the radial direction is preferable. Also in this case, regarding the longitudinal cross-sectional shape of the annular portion 10, the radially outer side (E2 _o ) of the back surface 14 side is an arc shape, and the radially inner side (E1 _i ) of the one side surface 11 side is an arc shape. It can be.
The double row roller bearing 1 may be used for purposes other than supporting the main shaft 6 of the machine tool.

1: Double-row roller bearing 2: Inner ring 3: Outer ring 4: Roller 10: Ring portion 11: One side surface 14: Back surface 20: Column portion E1o: A radially outer portion on one side surface E1i: Radial direction on one side surface side Inner part E2o: radially outer part on the back side E2i: radially inner part on the back side P: part including an annular part and a column part G: centroid

Claims (4)

A comb-type cage that is incorporated in a double-row roller bearing in which a plurality of rollers are arranged in a double row state between an inner ring and an outer ring, holds the plurality of rollers for each row, and allows the back surfaces to be in contact with each other. Because
An annular portion having the annular back surface, and a plurality of column portions that extend in the axial direction from one side surface that is opposite to the rear surface of the annular portion in the axial direction and are spaced apart in the circumferential direction. Prepared,
A longitudinal cross-sectional shape of the annular portion is an arc shape on the radially outer side of the back surface side, and an arc shape on the radially inner side of the one side surface. Comb cage.   The comb cage for a double row roller bearing according to claim 1, wherein a vertical cross-sectional shape of the annular portion is a circle, an ellipse, or an ellipse.   3. The comb for a double row roller bearing according to claim 1, wherein a centroid position of a longitudinal section in a portion including the annular portion and the column portion is within a range of the longitudinal section of the annular portion. Mold retainer. An inner ring, an outer ring, a plurality of rollers arranged in a double row between the inner ring and the outer ring, and two independent cages for holding a plurality of the rollers for each row,
Each of the cages is provided with an annular portion having an annular back surface, and an axial direction extending from one side surface opposite to the rear surface of the annular portion in the axial direction and spaced apart in the circumferential direction. A comb-shaped cage provided with a plurality of pillars and provided so that the back surfaces can be in contact with each other,
The double-row roller bearing is characterized in that a longitudinal cross-sectional shape of the annular portion has an arc shape on the radially outer side of the back surface side and an arc shape on the radially inner side of the one side surface side.