KR101368100B1 - Rolling bearing and spindle device for machine tool - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides a rolling bearing and a spindle device for a machine tool that can reduce the abnormal temperature rise of a rolling bearing and shorten the time required for the taming operation when performing grease lubrication by improving the dischargeability of the lubricant. to provide. The retainer 10 used for the rolling bearing of the present invention has a predetermined interval in the circumferential direction so as to connect the pair of ring portions 12 arranged side by side in the axial direction and the pair of ring portions 12. It has a some pillar part 16 arrange | positioned by the. Each ring portion 12 has a plurality of convex protrusions 15 formed on each outer circumferential surface 13 in a circumferential direction. The convex protrusion part 15 of one circular part 12 is formed in the position different from the convex protrusion part 15 of the other circular part 12 in the circumferential direction.

Description

Rolling bearing and spindle device for machine tools {ROLLING BEARING AND SPINDLE DEVICE FOR MACHINE TOOL}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to rolling bearings and spindle devices for machine tools, and more particularly to rolling bearings used for spindles of high speed rotating machine tools, high speed motors, and the like, and spindle devices for machine tools using the same.

In recent years, the bearing used for the spindle device for machine tools has advanced in speed for high efficiency processing. If the discharge property of the lubricant is poor in the bearing rotating at high speed, the lubricant is in an excessive state, and abnormal heat generation occurs due to the heat of stirring. In such a case, the bearing temperature rises abnormally and the bearing may be broken.

10 shows a cylindrical roller bearing 100 that is conventionally used. The cylindrical roller bearing 100 includes an outer ring 102 having an outer ring raceway 102a on its inner circumferential surface, an inner ring 103 having an inner ring raceway 103a on its outer circumferential surface, and an outer ring raceway 102a and an inner ring raceway 103a. And a holder (110) having a plurality of rollers (104) formed so as to be freely rotatable in the plurality, and a plurality of pockets (111) holding the plurality of rollers (104). Here, the retainer 110 is an outer ring guide system, and the outer circumferential surface 110a of the retainer 110 functions as a guided surface.

In the retainer 110 of the outer ring guide system, since the guide gap g 'between the outer circumferential surface 110a of the retainer 110 and the inner circumferential surface of the outer ring 102 is narrow, the discharge property of the lubricant is poor, and the cylinder The abnormal temperature rise of the roller bearing 100 tends to occur. Moreover, in the cylindrical roller bearing 100, since the outer ring raceway 102a and the inner ring raceway 103a and the roller (motor) 104 are in line contact, the outer ring raceway 102a and the inner ring raceway 103a. ) And the cylindrical roller bearing 100 are more likely to be heated up than the ball bearing in which the ball (motor) is in point contact.

When grease lubrication is carried out, so-called break-in operation is indispensable in order to uniformly disperse the sealed grease in the bearing after the grease is sealed in the bearing or to move the excess grease to the periphery of the bearing. In the outer ring guide system retainer 110, since the guide gap g 'between the outer circumferential surface 110a of the retainer 110 and the inner circumferential surface of the outer ring 102 is narrow, discharge of the lubricant is poor, and the break-in operation Tends to take time.

In order to improve the discharge | release property of a lubrication agent, it is conventionally proposed to form a recessed part in the guide surface of a holder (for example, refer patent document 1, patent document 2).

Japanese Patent No. 3651591 Japanese Patent No.4342612

According to the rolling bearing of patent documents 1 and 2, the drainage property of a lubrication agent can be improved by the recessed part formed in the guide surface of a holder. However, when the lubricant is excessive, there is a problem that abnormal temperature rise of the rolling bearing is likely to occur.

This invention is made | formed in view of the said situation, The objective is to improve the discharge | release property of a lubrication agent, to suppress abnormal temperature rising of a rolling bearing, and to shorten the time required for the tamping operation at the time of grease lubrication. It is to provide a rolling bearing and a spindle device for machine tools.

The above object of the present invention is achieved by the following arrangement.

(1) an inner ring having an inner ring track on its outer circumferential surface, an outer ring having an outer ring track on its inner circumferential surface, a plurality of rolling elements formed so as to be freely electrically transmitted between the inner ring track and the outer ring track, and holding the plurality of rolling elements A rolling bearing having a retainer having a plurality of pockets,

The holder includes a plurality of pillars arranged at predetermined intervals in a circumferential direction so as to connect the first and second ring portions arranged side by side in the axial direction, and the first and second ring portions. With wealth,

The first ring portion and the second ring portion has a plurality of convex protrusions formed on each outer circumferential surface to be spaced apart in the circumferential direction,

The convex projection of the second annular portion is formed in a position different from the convex projection of the first annular portion in a circumferential direction.

(2) The rolling bearing according to the above (1), wherein the convex protrusions of the first ring portion and the convex protrusions of the second ring portion are formed at equal intervals in the circumferential direction, respectively.

(3) The rolling bearing according to the above (1) or (2), wherein the convex protrusions of the first ring portion and the convex protrusions of the second ring portion are formed adjacent to the pillar portion in the axial direction, respectively.

(4) The spindle device for machine tools in which the rolling bearing in any one of said (1)-(3) is used.

According to the rolling bearing of the present invention and the spindle device for machine tools, the lubricant can be smoothly discharged from the portion where the convex protrusion of the holder is not formed. Thereby, abnormal temperature rising of a rolling bearing can be suppressed, and the time of a break-in operation can be shortened when grease lubrication is performed.

1 is a cross-sectional view of a rolling bearing according to a first embodiment of the present invention.
2 is a perspective view of the retainer of FIG. 1.
3: shows the retainer of FIG. 2, 3 (a) is a front view, 3 (b) is a partial top view seen from the I direction of 3 (a).
4: shows the retainer of the rolling bearing which concerns on 2nd Embodiment of this invention, 4 (a) is a front view, 4 (b) is a partial top view seen from II direction of 4 (a).
FIG. 5: shows the holder of the rolling bearing which concerns on 3rd Embodiment of this invention, 5 (a) is a front view, 5 (b) is a partial top view seen from the III direction of 5 (a).
6 is a cross-sectional view showing the test apparatus used in Examples 1 and 2. FIG.
7 is a graph showing the test results of Example 1. FIG.
8: shows the holder used for the rolling bearing of the comparative example 2, 8 (a) is a front view and 8 (b) is a partial top view seen from the X direction of 8 (a).
9 is a graph showing the test results of Example 2. FIG.
10 is a cross-sectional view of a conventional rolling bearing.

EMBODIMENT OF THE INVENTION Hereinafter, each embodiment of the rolling bearing which concerns on this invention is described in detail based on drawing.

(First Embodiment)

The rolling bearing which concerns on 1st Embodiment of this invention is demonstrated based on FIG. FIG. 1: shows sectional drawing of the cylindrical roller bearing 1 which concerns on 1st Embodiment. FIG. 2 shows a perspective view of the retainer 10 of FIG. 1. 3 shows the retainer 10 of FIG. 2, 3 (a) is a front view of the retainer 10, and 3 (b) is a partial top view seen from the I direction of 3 (a).

As shown in FIG. 1, the cylindrical roller bearing 1 has the outer ring 2 in which the outer ring track surface 2a was formed in the inner peripheral surface, the inner ring 3 in which the inner ring track surface 3a was formed in the outer peripheral surface, and a plurality of rolling elements. Cylindrical rollers 4 and a retainer 10 disposed between the outer ring 2 and the inner ring 3. A plurality of pockets 11 are formed in the holder 10, and a plurality of cylindrical rollers 4 are held in each pocket 11 so that they can be freely rotated.

As shown in FIG. 2, the holder 10 is arranged at a predetermined interval in the circumferential direction so as to connect the pair of ring portions 12 arranged side by side in the axial direction and the two ring portions 12. It has a plurality of pillar portions 16 that have been formed. The pocket 11 is formed by the pair of ring portions 12 and two pillar portions 16 adjacent in the circumferential direction. Moreover, the roller fixing part 14 for reliably holding the cylindrical roller 4 is formed in the circumferential direction both sides of the axial direction intermediate part of the pillar part 16 so that it may protrude from the outer peripheral surface of the pillar part 16. As shown in FIG.

On the outer circumferential surface 13 of the pair of ring portions 12, a plurality of convex protrusions 15 are formed at predetermined intervals in the circumferential direction. Each of the convex protrusions 15 has an outer circumferential surface of the circular portion 12 from both sides of the convex protrusion circumferential surface 15a having a larger diameter than the outer circumferential surface of the column portion 16 and the circumferential sides of the convex protrusion circumferential surface 15a. It has a pair of granular part 15b continuous by (13). The retainer 10 is an outer ring guide system in which the convex protrusion outer peripheral surface 15a is guided by a retainer guide surface formed on the inner circumferential surface of the outer ring 2.

Moreover, the convex protrusion part 15 is arrange | positioned so that it may be adjacent to the pillar part 16 in the axial direction on the outer peripheral surface 13 of each original part 12. As shown in FIG. Here, as shown to FIG. 2, FIG. 3 (a) and 3 (b), in the holder 10 used for 1st Embodiment WHEREIN: The several convex protrusion part 15 of each ring part 12 is shown. ) Is arranged to be adjacent in the axial direction with respect to the other pillar portion 16. Moreover, the convex protrusion part 15 of the one ring part 12 has an axis | shaft with respect to the pillar part 16 which the convex protrusion part 15 of the other ring part 12 does not adjoin in an axial direction. It is arrange | positioned so that it may adjoin in a direction. That is, the convex protrusions 15 are arranged so that the convex protrusions 15 do not exist on both sides of the column portion 16 in the axial direction, and are arranged in a zigzag shape alternately left and right of the column portions 16. It is arranged on the outer circumferential surface of the pair of ring portions 12.

Thus, the cylindrical roller bearing 1 of 1st Embodiment has the retainer 10 in which the several convex protrusion part 15 was formed in the circumferential direction at predetermined intervals on the outer peripheral surface 13, and is convex-shaped The protruding portion 15 is formed so as to be adjacent to only one side in the axial direction of the pillar portion 16. Therefore, in the axial direction one side of the pillar part 16, even if the guide gap g between the convex protrusion outer peripheral surface 15a and the holder guide surface is the same as the conventional guide gap g ', the pillar part 16 ), The gap G between the outer circumferential surface 13 of the annular portion 12 and the inner circumferential surface (oil retainer guide surface) of the outer ring 2 on the other side in the axial direction or a portion where the pillar portion 16 does not exist. This is big. Therefore, the lubricant can be smoothly discharged from this gap G. In addition, the difference in the size of the guide gap g and the size of the gap G causes a pressure difference between the two ring portions 12 to cause convection of air, which further promotes the discharge of the lubricant by the convection action. Moreover, since the air resistance at the time of high speed rotation is alleviated by having the granular part 15b which continues from the circumferential direction both sides of the convex protrusion outer peripheral surface 15a to the outer peripheral surface 13 of the ring part 12, respectively, The drainage of the lubricant is further improved. Therefore, according to the cylindrical roller bearing 1 which concerns on this embodiment, abnormal temperature rising at the time of high speed rotation can be suppressed, and even if grease lubrication is performed, the time of a break-in operation can be shortened.

(Second Embodiment)

Next, the rolling bearing which concerns on 2nd Embodiment of this invention is demonstrated based on FIG. 4 shows a retainer 20 used in the cylindrical roller bearing according to the second embodiment, 4 (a) is a front view of the retainer 20, and 4 (b) is in the II direction of 4 (a). This is a partial top view.

The holder 20 used in the second embodiment is a pair of ring portions 22 arranged side by side in the axial direction similarly to the holder 10 used in the first embodiment, and both ring rings. It has a some pillar part 26 arrange | positioned at predetermined space | intervals in the circumferential direction so that the parts 22 may be connected. The pocket 21 is formed by the pair of ring portions 22 and two pillar portions 26 neighboring in the circumferential direction. Moreover, the roller fixing part 24 is formed in the circumferential direction both sides of the axial direction intermediate part of the pillar part 26 so that it may protrude from the outer peripheral surface of the pillar part 26. As shown in FIG.

On the outer circumferential surface 23 of the pair of ring portions 22, a plurality of convex protrusions 25 are formed at predetermined intervals in the circumferential direction. Each convex protrusion part 25 has the outer peripheral surface 25 of the convex protrusion part 25a larger diameter than the outer peripheral surface of the column part 26, and the outer peripheral surface of the circular part 22 from the circumferential direction both sides of the convex protrusion part outer peripheral surface 25a, respectively. It has a pair of granular part 25b continuous by (23). The retainer 20 is an outer ring guide system in which the convex protrusion outer peripheral surface 25a is guided by the retainer guide surface formed on the inner circumferential surface of the outer ring.

Also in the holder 20 used in 2nd Embodiment, the convex protrusion part 25 is arrange | positioned so that the convex protrusion part 25 may not exist in the axial direction both sides of the pillar part 26. In the retainer 20, unlike the first embodiment, the plurality of convex protrusions 15 of the respective ring portions 12 are in the axial direction with respect to the pillar portion 16 in which the two are filtered. It is arrange | positioned so that it may adjoin. By such arrangement, the lubricant can be discharged more smoothly from the cylindrical roller bearing, so that abnormal temperature rise during high-speed rotation can be suppressed, and even when grease lubrication is performed, the time for taming operation can be shortened.

(Third Embodiment)

Next, 3rd Embodiment of this invention is described based on FIG. FIG. 5 shows a retainer 30 used in the angular ball bearing according to the third embodiment, 5 (a) is a front view of the retainer 30, and 5 (b) is in the III direction of 5 (a). This is a partial top view.

The holder 30 shown in FIG. 5 is a pair of ring portions 32 and both ring portions 32 arranged side by side in the axial direction similarly to the holder 10 used in the first embodiment. ), A plurality of pillars 36 arranged at predetermined intervals in the circumferential direction. The pocket 31 is formed by the pair of ring portions 32 and two pillar portions 36 neighboring in the circumferential direction.

The outer circumferential surface 33 of the pair of ring portions 32 has a convex protrusion portion outer circumferential surface 35a having a larger diameter than the outer circumferential surface of the pillar portion 36, and a pair of convex protrusion circumferential side surfaces 35b. The plurality of convex protrusions 35 are formed at predetermined intervals in the circumferential direction. The pair of convex protrusions circumferential side surfaces 35b are substantially perpendicular to the outer circumferential surface 33 of the annular portion 32 and the convex protrusions outer circumferential surface 35a on both sides of the circumferential direction of the convex protrusions outer circumferential surface 35a. You are connected to The retainer 30 is an outer ring guide system in which the convex protrusion outer peripheral surface 35a is guided by the retainer guide surface formed on the inner circumferential surface of the outer ring. During the rotation of the angular ball bearing, the convex protrusion outer peripheral surface 35a is lubricated by a lubricant accumulated at the intersection of the convex protrusion circumferential side surface 35b and the outer peripheral surface 33 of the ring portion 32.

Also in the holder 30 used in 3rd Embodiment, the convex protrusion part 35 is arrange | positioned so that the convex protrusion part 35 may not exist in the axial direction both sides of the pillar part 36. In addition, similarly to the holder 10 used in the first embodiment, the plurality of convex protrusions 35 of the respective annular portions 32 are in the axial direction with respect to the pillar portion 36 in which one is filtered. It is arrange | positioned so that it may adjoin. Since such a lubrication agent can be discharged | emitted smoothly from an angular ball bearing, abnormal temperature rise at the time of high speed rotation can be suppressed, and even if grease lubrication is performed, the time of break-in operation can be shortened.

In addition, this invention is not limited to said embodiment, A change, improvement, etc. are possible suitably. In the said embodiment, although the cylindrical roller bearing and the angular ball bearing were demonstrated, this invention is applicable also to other rolling bearings, such as a deep groove ball bearing and a conical roller bearing. In consideration of the use at high speed rotation, as the retainer material, a synthetic resin that is lighter than metal and excellent in wear resistance is preferable, and phenol, polyamide, PPS, PEEK, polyimide, and the like are preferable. Moreover, reinforcing agents, such as glass fiber, carbon fiber, and aramid fiber, may be added to these.

Moreover, the convex protrusion part is not limited to the arrangement | positioning adjacent to a pillar part in the axial direction, and may be arrange | positioned on the outer peripheral surface of a circular part. For example, the convex protrusions may be arranged to be adjacent to the pocket in the axial direction. Even when the convex protrusions are adjacent to one side of the pocket in the axial direction, the guide gap g on the one side of the pocket in the axial direction is the same as long as the convex protrusions are not disposed on the other side of the pocket in the axial direction. It becomes a magnitude | size different from the clearance gap G in the other side of an axial direction, a pressure difference arises between a circular part, and air convection arises. As a result, the discharge of the lubricant is promoted by the convection action. In addition, whether to form a granular part in the circumferential direction both sides of a convex protrusion part, or to form the lateral side surface of a convex protrusion part circumferential direction can be determined suitably according to the use purpose of a rolling bearing.

Example 1

Here, the test was performed about the relationship between the temperature increase at the time of high speed rotation of a rolling bearing, and the shape of a holder. 6 is a cross-sectional view of the evaluation test apparatus 50 used in this test, and the housing 51 so that the cylindrical roller bearing 1 as a test bearing carries one end side of the rotation shaft 52. ) Is installed. The supply of lubricant to the cylindrical roller bearing 1 is performed through the nozzle 53. The test was performed using the cylindrical roller bearing 1 (invention example) shown in FIG. 1, and the cylindrical roller bearing 100 (comparative example 1) shown in FIG. The test conditions (test condition 1) of Example 1 are shown below.

(Test Condition 1)

Bearing: Cylindrical Roller Bearing (N1011RSTPKR)

Size: inner diameter Φ55 mm x outer diameter Φ90 mm x width 18 mm

Flow conditions: 0.01 cc / 1 shot (intermittent lubrication every 2 minutes)

Use oil ： Turbine oil VG32

7 shows the test results of Example 1. FIG. 7, the cylindrical roller bearing 100 of the comparative example 1 is heated up rapidly as time passes from the start of operation, and rotation becomes high speed, whereas the temperature rise is suppressed in the cylindrical roller bearing 10 of an invention example. I can see that there is. From this test result, it turns out that the discharge property of a lubrication agent is improved in the cylindrical roller bearing 1 of the example of this invention, and abnormal temperature rise can be suppressed.

Example 2

About the relationship between the temperature rising at the time of high speed rotation of a rolling bearing, and the shape of a retainer, Example 1 changed the test conditions and tested. Also in the test of Example 2, the evaluation test apparatus 50 shown in FIG. 6 is used similarly to Example 1. FIG. The test is a rolling bearing in which the cylindrical roller bearing 1 (invention example) shown in FIG. 1, the cylindrical roller bearing 100 (comparative example 1) shown in FIG. 10, and the retainer 210 shown in FIG. 8 are used. It carried out using (Comparative Example 2). The test conditions (test condition 2) of this test are shown below.

(Test Condition 2)

Bearing ： Cylindrical Roller Bearing (N1011RSTPKR)

Size ： Inner diameter Φ55 mm × appearance Φ90 mm × width 18 mm

Flow conditions: 0.01 cc / 1 shot (8-minute intervals of lubrication)

Use oil ： Turbine oil VG32

The holder 210 shown in FIG. 8 is a pair of ring portions 212 and two ring rings arranged side by side in the axial direction similarly to the holder 10 used in the first embodiment of the present invention. In order to connect between the parts 212, it has a some pillar part 216 arrange | positioned at predetermined intervals in the circumferential direction. The pocket 211 is formed by the pair of ring portions 212 and two pillar portions 216 neighboring in the circumferential direction. On the outer circumferential surface 213 of the pair of ring portions 212, a plurality of convex protrusions 215 are formed so as to sandwich the pillar portion 216 from both sides in the axial direction. Each convex protrusion part 215 has the convex protrusion part outer peripheral surface 215a larger than the outer peripheral surface of the column part 216. As shown in FIG. The retainer 210 is an outer ring guide system in which the convex protrusion outer peripheral surface 215a is guided by the retainer guide surface formed on the inner circumferential surface of the outer ring.

9 shows the test results of Example 2. FIG. From FIG. 9, it turns out that the temperature rise of the cylindrical roller bearing 1 of the invention example is suppressed compared with the cylindrical roller bearing of Comparative Examples 1 and 2. FIG. From this test result, it turns out that the discharge property of a lubrication agent is improved in the cylindrical roller bearing 1 of the example of this invention, and temperature rising is suppressed.

Here, the temperature rise is suppressed in the cylindrical roller bearing 1 of the invention example rather than the cylindrical roller bearing of the comparative example 2, In the retainer 210 used for the comparative example 2, the convex protrusion part 215 is a column part ( In the holder 10 used in the invention example, the convex protrusions 15 are formed on only one side of the column portion 16 in the axial direction, while the 216 is disposed on both sides in the axial direction. I think. As for the column part 216 of the holder 210 used for the comparative example 2, the outer diameter direction is convex by an outer ring (not shown), the circumferential direction both sides are cylindrical rollers (not shown), and the axial direction both sides are convex. It is surrounded by the shape protrusion 215, and the closed space is formed. Since convection of air hardly occurs in this waste space, the lubricant which has entered the waste space is hardly discharged from the waste space to the outside.

On the other hand, in the cylindrical roller bearing 1 of the invention example, the lubricant adhering to the outer peripheral side of the pillar part 16 is the one side of the axial direction of the pillar part 16 (the side in which the convex protrusion part 15 is not formed). Can be discharged smoothly. In addition, as the sizes of the guide gap g and the gap G formed between the holder 10 and the outer ring 2 are different on both sides of the column 16 in the axial direction, both ring portions 12 There is a pressure differential between the air masses, resulting in air convection. As a result, the discharge of the lubricant is further promoted by the convection action, so that the discharge property of the lubricant is improved. Therefore, according to the cylindrical roller bearing 1 which concerns on the invention example, abnormal temperature rising at the time of high speed rotation can be suppressed, and even if grease lubrication is performed, the time of a break-in operation can be shortened.

As mentioned above, although embodiment and Example of this invention were described, this invention is not limited to embodiment mentioned above, It can change and implement in various ways only as described in a claim. This application is based on the JP Patent application (Japanese Patent Application 2010-183349) of an application on August 18, 2010, The content is taken in here as a reference.

1: cylindrical roller bearing
2: paddle
2a: outer ring raceway
3: inner ring
3a: inner ring raceway
4: cylindrical roller
10: retainer
11: pocket
12: original part
15: convex protrusion
16: column

Claims (4)

An inner ring having an inner ring track on its outer circumference, an outer ring having an outer ring track on its inner circumferential surface, a plurality of rolling elements formed so as to be freely electrically transmitted between the inner ring track and the outer ring track, and a plurality of pockets holding the plurality of rolling elements As a rolling bearing having a retainer having:
The holder includes a plurality of pillars arranged at predetermined intervals in a circumferential direction so as to connect the first and second ring portions arranged side by side in the axial direction, and the first and second ring portions. With wealth,
The first ring portion and the second ring portion has a plurality of convex protrusions formed on each outer circumferential surface to be spaced apart in the circumferential direction,
The convex projections of the second ring portion are formed at positions different in the circumferential direction from the convex protrusions of the first ring portion,
The convex projections of the first annular portion and the convex projections of the second annular portion are formed at equal intervals in the circumferential direction, respectively. delete The method of claim 1,
The convex-shaped protrusion part of the said 1st ring part, and the convex-shaped protrusion part of a said 2nd ring part are rolling bearings respectively formed adjacent to the said pillar part in the axial direction. The spindle device for machine tools in which the rolling bearing of Claim 1 or 3 is used.

Images