TWI481786B - Rolling bearings and machine tool spindle device - Google Patents

Description

Spindle device for rolling bearing and machine tool

The present invention relates to a spindle device for a rolling bearing and a machine tool, and more particularly to a rolling bearing used in a spindle of a high-speed rotating machine tool, a high-speed motor, or the like, and a spindle device using the same.

In recent years, the bearings used in the spindle device for machine tools have been increasing in speed for high-efficiency machining. If the lubricant is poorly discharged in a high-speed rotating bearing, the lubricant will be in an excessive state, and abnormal heat generation will occur due to the stirring heat. In this case, the bearing temperature abnormally rises, and the bearing is broken.

Figure 10 shows a cylindrical roller bearing 100 previously used. The cylindrical roller bearing 100 includes an outer wheel (outer ring) 102 having an outer wheel track 102a on the inner circumferential surface, an inner wheel (inner ring) 103 having an inner wheel track 103a on the outer circumferential surface, and a plurality of rollers 104. Roller freely disposed between the outer wheel track 102a and the inner wheel track 103a; and a retainer 110 having a plurality of pockets 111 holding a plurality of rollers 104. Here, the retainer 110 is an outer wheel guide type, and the outer peripheral surface 110a of the retainer 110 functions as a guided surface.

In the outer wheel guide type retainer 110, since the guide gap g' between the outer peripheral surface 110a of the retainer 110 and the inner peripheral surface of the outer ring 102 is narrow, the discharge property of the lubricant is poor, and the cylinder is liable to be caused. The tendency of the roller bearing 100 to abnormally heat up. Further, in the cylindrical roller bearing 100, since the outer race track 102a and the inner race track 103a are in line contact with the roller (rolling element) 104, the ball is in point contact with the outer race track 102a and the inner race track 103a and the ball (rolling body). The cylindrical roller bearing 100 is prone to temperature rise compared to the bearing.

Moreover, in the case of grease lubrication, after the grease is sealed in the bearing, it is indispensable to uniformly disperse the sealed grease into the bearing or to move excess grease to the peripheral portion of the bearing. Run-in operation. In the outer wheel guide type retainer 110, since the guide gap g' between the outer peripheral surface 110a of the retainer 110 and the inner peripheral surface of the outer ring 102 is narrow, the discharge of the lubricant is poor, and the running-in operation takes time. The tendency.

In order to improve the discharge property of the lubricant, a method of providing a concave portion on the guided surface of the retainer has been proposed (for example, refer to Patent Document 1 and Patent Document 2).

Prior technical literature Patent literature

Patent Document 1: Japanese Patent No. 3651591

Patent Document 2: Japanese Patent No. 4342612

According to the rolling bearing described in Patent Documents 1 and 2, the discharge property of the lubricant can be improved by being provided in the concave portion of the guided surface of the retainer. However, in the case where the lubricant is excessive, there is a problem that the rolling bearing is likely to be abnormally heated.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a rolling bearing capable of suppressing an abnormal temperature rise of a rolling bearing by increasing the discharge property of the lubricant and shortening the time required for the running-in operation in the case of performing grease lubrication. And the spindle device for the machine tool.

The above object of the present invention can be achieved by the following constitution.

(1) A rolling bearing comprising: an inner wheel having an inner wheel track on an outer circumferential surface; an outer wheel having an outer wheel track on an inner circumferential surface; and a plurality of rolling bodies rotatably disposed on the inner wheel track and the outer wheel And a retainer having a plurality of pockets for holding the plurality of rolling elements, wherein the retainer includes: a first annular portion and a second annular portion, which are arranged in the axial direction; and plural Each of the first annular portion and the second annular portion has a predetermined interval in the circumferential direction so as to connect the first annular portion and the second annular portion, and the first annular portion and the second annular portion have an outer circumferential surface thereof The plurality of convex protrusions are formed apart in the circumferential direction, and the convex protrusions of the second annular portion are formed at positions different from the convex protrusions of the first annular portion.

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

(3) The rolling bearing according to the above aspect (1), wherein the convex protrusion of the first annular portion and the convex protrusion of the second annular portion are adjacent to the column portion in the axial direction. form.

(4) A spindle device for a machine tool, which uses the rolling bearing according to any one of the above (1) to (3).

According to the spindle device for a rolling bearing and a machine tool according to the present invention, the lubricant can be smoothly removed from the portion of the retainer where the convex projection is not provided. Thereby, the abnormal temperature rise of the rolling bearing can be suppressed, and the time of the running-in operation can be shortened when the grease is lubricated.

Hereinafter, each embodiment of the rolling bearing of the present invention will be described in detail based on the drawings.

(First embodiment)

A rolling bearing according to a first embodiment of the present invention will be described with reference to Fig. 1 . Fig. 1 is a cross-sectional view showing a cylindrical roller bearing 1 of the first embodiment. Figure 2 shows a perspective view of the holder 10 of Figure 1. Fig. 3 shows the retainer 10 of Fig. 2, Fig. 3(a) is a front view of the retainer 10, and Fig. 3(b) is a partial plan view as seen from the direction I of Fig. 3(a).

As shown in Fig. 1, the cylindrical roller bearing 1 includes an outer ring 2 having an outer raceway surface 2a formed on an inner peripheral surface thereof, and an inner race 3 having an inner raceway surface 3a formed on an outer peripheral surface thereof; a cylindrical roller 4; and a retainer 10 disposed between the outer wheel 2 and the inner wheel 3. A plurality of pockets 11 are formed in the holder 10, and a plurality of cylindrical rollers 4 are rotatably held in the respective pockets 11.

As shown in FIG. 2, the retainer 10 includes a pair of annular portions 12 arranged in the axial direction, and a plurality of column portions 16 which are spaced apart in the circumferential direction in such a manner as to connect between the two annular portions 12. Configuration. The bag body 11 is formed by a pair of annular portions 12 and two column portions 16 adjacent in the circumferential direction. Further, on both sides in the circumferential direction of the intermediate portion in the axial direction of the column portion 16, a roller stopper portion 14 for holding the cylindrical roller 4 securely is provided so as to protrude from the outer peripheral surface of the column portion 16.

A plurality of convex protrusions 15 are formed at a predetermined interval in the circumferential direction on the outer peripheral surface 13 of the pair of annular portions 12. Each of the convex protrusions 15 includes a convex protrusion outer peripheral surface 15a having a larger diameter than the outer peripheral surface of the column portion 16, and a pair of upright portions 15b which are continuous from both sides in the circumferential direction of the convex protrusion outer peripheral surface 15a. To the outer peripheral surface 13 of the annular portion 12. The holder 10 guides the outer peripheral surface 15a of the convex protrusion portion by the wheel guide method formed on the holder guide surface formed on the inner circumferential surface of the outer ring 2.

Further, the convex protrusions 15 are disposed on the outer peripheral surface 13 of each annular portion 12 so as to be adjacent to the column portion 16 in the axial direction. Here, as shown in FIG. 2, FIG. 3(a) and FIG. 3(b), in the holder 10 used in the first embodiment, the plurality of convex protrusions 15 of each annular portion 12 are every One column portion 16 is disposed adjacent to the column portion 16 in the axial direction. Further, the convex protrusions 15 of the one annular portion 12 are arranged adjacent to each other in the axial direction with respect to the column portion 16 which is not adjacent to the axial direction of the convex protrusion portion 15 of the other annular portion 12. In other words, the convex protrusions 15 are disposed so as not to have the convex protrusions 15 on both sides in the axial direction of the column portion 16, and are arranged in a pair of annular portions so as to be alternately arranged in a staggered manner on the right and left sides of the column portion 16. 12 outer peripheral surface.

In the cylindrical roller bearing 1 of the first embodiment, the retainer 10 in which a plurality of convex protrusions 15 are formed at a predetermined interval in the circumferential direction on the outer peripheral surface 13 is provided, and the convex protrusions 15 are adjacent only to the column portion. Formed on either side of the 16-axis direction. Therefore, in the axial direction side of the column portion 16, even if the guide gap g between the convex projection outer peripheral surface 15a and the retainer guide surface is the same as the previous guide gap g', in the axial direction of the column portion 16 On the other side or the portion where the column portion 16 is not present, the gap G between the outer peripheral surface 13 of the annular portion 12 and the inner peripheral surface (holder guide surface) of the outer ring 2 is also large. Therefore, the lubricant can be smoothly discharged from the gap G. Further, by the difference in the size of the gap g and the size of the gap G, a pressure difference is generated between the two annular portions 12, thereby causing air convection, and the discharge of the lubricant is further promoted by the convection action. Further, by having the upright portions 15b extending from the circumferential sides of the outer peripheral surface 15a of the convex protrusions to the outer peripheral surface 13 of the annular portion 12, the air resistance at the time of high-speed rotation can be alleviated, and the discharge of the lubricant can be relaxed. Further improve. Therefore, according to the cylindrical roller bearing 1 of the present embodiment, it is possible to suppress abnormal temperature rise during high-speed rotation, and it is also possible to shorten the time of the running-in operation when lubricating grease is performed.

(Second embodiment)

Next, a rolling bearing according to a second embodiment of the present invention will be described based on Fig. 4 . Fig. 4 is a view showing a retainer 20 used in a cylindrical roller bearing according to a second embodiment, wherein Fig. 4(a) is a front view of the retainer 20, and Fig. 4(b) is a view from the direction II of Fig. 4(a). Partial top view.

The retainer 20 used in the second embodiment includes a pair of annular portions 22 arranged in the axial direction, and a plurality of column portions 26, which are the same as the retainer 10 used in the first embodiment. The manner in which the two annular portions 22 are connected is arranged at a specific interval in the circumferential direction. The bag body 21 is formed by a pair of annular portions 22 and two column portions 26 adjacent to each other in the circumferential direction. Further, the roller blocking portion 24 is provided on both sides in the circumferential direction of the intermediate portion in the axial direction of the column portion 26 so as to protrude from the outer peripheral surface of the column portion 26.

A plurality of convex protrusions 25 are formed at a predetermined interval in the circumferential direction on the outer peripheral surface 23 of the pair of annular rings 22. Each of the convex protrusions 25 includes a convex protrusion outer peripheral surface 25a having a larger diameter than the outer peripheral surface of the column portion 26, and a pair of upright portions 25b which are continuous from both sides in the circumferential direction of the convex protrusion outer peripheral surface 25a. To the outer peripheral surface 23 of the annular portion 22. The holder guides the outer peripheral surface 25a of the convex protrusion portion by the wheel guide method formed on the holder guide surface formed on the inner circumferential surface of the outer ring.

In the retainer 20 used in the second embodiment, the convex protrusions 25 are disposed so that the convex protrusions 25 are not present on both sides in the axial direction of the column portion 26. Further, in the holder 20, unlike the first embodiment, the plurality of convex protrusions 15 of the respective annular portions 12 are arranged adjacent to the column portion 16 in the axial direction every two column portions 16. According to this arrangement, the lubricant can be discharged from the cylindrical roller bearing more smoothly, so that abnormal temperature rise during high-speed rotation can be suppressed, and the time of the running-in operation can be shortened in the case of performing grease lubrication.

(Third embodiment)

Next, a third embodiment of the present invention will be described based on Fig. 5 . Fig. 5 is a view showing a retainer 30 used in the angular contact ball bearing of the third embodiment, Fig. 5(a) is a front view of the retainer 30, and Fig. 5(b) is a view from the direction III of Fig. 5(a). Partial top view.

Similarly to the retainer 10 used in the first embodiment, the retainer 30 shown in Fig. 5 includes a pair of annular portions 32 arranged in the axial direction, and a plurality of column portions 36 for connecting the two annular portions. The manner between 32 is arranged at a specific interval in the circumferential direction. The bag body 31 is formed by a pair of annular portions 32 and two column portions 36 adjacent to each other in the circumferential direction.

The outer peripheral surface 33 of the pair of annular portions 32 is formed with a plurality of convex protrusions 35 at a predetermined interval in the circumferential direction, and the convex protrusions include outer peripheral surfaces of convex protrusions having a larger diameter than the outer peripheral surface of the column portion 36. 35a and a pair of convex protrusions in the circumferential direction side surface 35b. The pair of convex-shaped projection circumferential surface 35b is connected to the outer circumferential surface 33 of the annular portion 32 and the outer circumferential surface 35a of the convex projection at substantially right angles on both sides in the circumferential direction of the outer circumferential surface 35a of the convex projection. The holder 30 guides the outer peripheral surface 35a of the convex projection by the wheel guide surface formed on the inner peripheral surface of the outer ring. During the rotation of the angular contact ball bearing, the convex projection outer peripheral surface 35a is lubricated by the lubricant remaining at the intersection of the circumferential side surface 35b of the convex projection and the outer peripheral surface 33 of the annular portion 32.

In the holder 30 used in the third embodiment, the convex protrusions 35 are also disposed so that the convex protrusions 35 are not present on both sides in the axial direction of the column portion 36. Further, similarly to the retainer 10 of the first embodiment, the plurality of convex projections 35 of the annular portions 32 are arranged adjacent to the column portion 36 in the axial direction every other column portion 36. According to this arrangement, the lubricant can be discharged from the angular contact ball bearing more smoothly, so that abnormal temperature rise at the time of high-speed rotation can be suppressed, and the time of the running-in operation can be shortened in the case of performing grease lubrication.

Furthermore, the present invention is not limited to the above embodiment, and can be appropriately modified, improved, and the like. In the above embodiment, the cylindrical roller bearing and the angular contact ball bearing have been described. However, the present invention can also be applied to other rolling bearings such as deep groove ball bearings and tapered roller bearings. Further, when considering the use under high-speed rotation, the retainer material is preferably a synthetic resin which is lighter in weight than metal and excellent in abrasion resistance, and may be phenol, polyamine or PPS (poly-p-phenylene). Sulfide, poly(p-phenylene sulfide), PEEK (polyetheretherketone, polyetheretherketone), polyimine, and the like. Further, a reinforcing agent such as glass fiber, carbon fiber or aromatic polyamide fiber may be added to the materials.

Further, the convex protrusion portion is not limited to being disposed adjacent to the column portion in the axial direction with respect to the column portion, and may be disposed at any position on the outer circumferential surface of the annular portion. For example, the convex protrusions may be arranged adjacent to the bag body in the axial direction. In other words, when the convex protrusion is adjacent to the axial direction of the bag body, as long as the convex protrusion is not disposed on the other side in the axial direction of the bag body, the guide gap g on the axial direction side of the bag body The gap G is different from the gap G on the other side in the axial direction of the bag body, so that a difference in the force between the annular portions causes air convection. Thereby, the discharge of the lubricant can be promoted by the convection action. Further, it is possible to appropriately provide an upright portion on both sides in the circumferential direction of the convex protrusion portion or a side surface in the circumferential direction of the convex protrusion portion, depending on the purpose of use of the rolling bearing.

Example 1

Here, the temperature rise at the time of high-speed rotation of the rolling bearing and the shape relationship of the retainer were tested. Fig. 6 is a cross-sectional view of the evaluation test apparatus 50 used in the test, and the cylindrical roller bearing 1 as a test bearing is assembled into the casing 51 so as to support one end side of the rotary shaft 52. The lubricant is supplied to the cylindrical roller bearing 1 via the nozzle 53. The test was carried out using the cylindrical roller bearing 1 (invention example) shown in Fig. 1 and the cylindrical rolling bearing 100 (Comparative Example 1) shown in Fig. 10 . The test conditions (test condition 1) of Example 1 are shown below.

(Test condition 1)

‧bearing: cylindrical roller bearing (N1011RSTPKR)

‧ Dimensions: inner diameter Φ 55 mm × outer diameter Φ 90 mm × width 18 mm

‧ oil quantity condition: 0.01 cc / 1 shot (intermittent oil supply at 2 minute intervals)

‧Use oil: Turbine oil VG32

Fig. 7 shows the test results of Example 1. As can be seen from FIG. 7 , the cylindrical roller bearing 100 of the first embodiment has been rapidly heated by the elapse of time since the start of the operation, and the temperature rise of the cylindrical roller bearing 10 of the invention is suppressed. According to the results of the test, in the cylindrical roller bearing 1 of the present invention, the discharge property of the lubricant is improved, and the abnormal temperature rise can be suppressed.

Example 2

The test conditions of Example 1 were changed to test the relationship between the temperature rise at the time of high-speed rotation of the rolling bearing and the shape of the retainer. In the test of Example 2, the evaluation test apparatus 50 shown in Fig. 6 was also used in the same manner as in the first embodiment. The test used the cylindrical roller shaft 1 (invention example) shown in Fig. 1, the cylindrical roller bearing 100 shown in Fig. 10 (Comparative Example 1), and the rolling bearing using the holder 210 shown in Fig. 8 (comparison Example 2) was carried out. The test conditions (test condition 2) of this test are shown below.

(Test condition 2)

‧bearing: cylindrical roller bearing (N1011RSTPKR)

‧ Dimensions: inner diameter Φ 55 mm × outer diameter Φ 90 mm × width 18 mm

‧ oil quantity conditions: 0.01 cc / 1 shot (intermittent oil supply at 8 minute intervals)

‧Use oil: Turbine oil VG32

The holder 210 shown in Fig. 8 includes a pair of annular portions 212 arranged in the axial direction, and a plurality of column portions 216, which are the same as the holder 10 used in the first embodiment of the present invention. The manner in which the two annular portions 212 are connected is arranged at a specific interval in the circumferential direction. The bag body 211 is formed by a pair of annular portions 212 and two column portions 216 adjacent to each other in the circumferential direction. A plurality of convex protrusions 215 are formed on the outer circumferential surface 213 of the pair of annular portions 212 so as to sandwich the column portions 216 from both sides in the axial direction. Each of the convex protrusions 215 includes a convex protrusion outer peripheral surface 215a having a diameter larger than the outer peripheral surface of the column portion 216. The holder 210 guides the outer peripheral surface 215a of the convex protrusion by the wheel guide type formed on the holder guide surface formed on the inner circumferential surface of the outer ring.

Fig. 9 shows the test results of Example 2. As is apparent from Fig. 9, the temperature rise of the cylindrical roller bearing 1 of the invention example was suppressed as compared with the cylindrical roller bearings of Comparative Examples 1 and 2. According to the results of the test, the discharge capacity of the lubricant in the cylindrical roller bearing 1 of the example of the present invention is improved, and the temperature rise is suppressed.

Here, it is considered that the reason why the temperature rise in the cylindrical roller bearing 1 of the invention is suppressed as compared with the cylindrical roller bearing of the comparative example 2 is as follows: the convex protrusion in the holder 210 used in the comparative example 2 The portion 215 is disposed on both sides in the axial direction of the column portion 216. On the other hand, in the retainer 10 used in the invention example, the convex protrusion portion 15 is formed only on either side of the axial direction of the column portion 16. The outer diameter direction of the column portion 216 of the retainer 210 used in Comparative Example 2 is surrounded by an outer wheel (not shown), and both sides of the circumferential direction are surrounded by a cylindrical roller (not shown), and both sides of the axial direction are convex. The protrusion 215 is surrounded to form a closed space. It is difficult to generate air convection in the closed space, and it is difficult for the lubricant entering the closed space to be discharged to the outside from the closed space.

On the other hand, in the cylindrical roller bearing 1 of the invention example, the lubricant adhering to the outer peripheral side of the column portion 16 can smoothly pass from the axial direction side of the column portion 16 (the side where the convex protrusion portion 15 is not formed). discharge. Further, the size of the guide gap g and the gap G formed between the retainer 10 and the outer ring 2 are different on both sides in the axial direction of the column portion 16, whereby a pressure difference is generated between the two annular portions 12 to cause generation. Air convection. Thereby, 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 of the invention example, the abnormal temperature rise at the time of high-speed rotation can be suppressed, and the time of the running-in operation can be shortened when the grease is lubricated.

The embodiments and examples of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention. The present application is based on Japanese Patent Application No. 2010-183349, filed on Jan.

1. . . Cylindrical roller bearing

2, 102. . . Outer wheel

2a, 102a. . . Outer wheel track surface

3, 103. . . Inner wheel

3a, 103a. . . Inner wheel track surface

4, 104. . . Round roller

10, 20, 30, 110, 210. . . Holder

11, 21, 31, 111, 211. . . Bag body

12, 22, 32, 212. . . Ring

13, 23, 33, 213. . . Outside the circumference of the ring

14, 24. . . Roller stop

15, 25, 35, 215. . . Convex protrusion

15a, 25a, 35a, 215a. . . Convex protrusion outer peripheral surface

15b, 25b. . . Erecting

35b. . . Convex protrusion circumferential side

16, 26, 216. . . Column

50. . . Evaluation test device

51. . . case

52. . . Rotary axis

53. . . nozzle

100. . . Cylinder rolling bearing

G. . . Void

g, g'. . . Guide gap

Fig. 1 is a cross-sectional view showing a rolling bearing according to a first embodiment of the present invention.

Figure 2 is a perspective view of the retainer of Figure 1.

Fig. 3 shows the retainer of Fig. 2, Fig. 3(a) is a front view, and Fig. 3(b) is a partial plan view seen from the direction I of Fig. 3(a).

Fig. 4 is a view showing a retainer for a rolling bearing according to a second embodiment of the present invention, wherein Fig. 4(a) is a front view, and Fig. 4(b) is a partial plan view seen from a direction II of Fig. 4(a).

Fig. 5 is a view showing a retainer for a rolling bearing according to a third embodiment of the present invention, wherein Fig. 5(a) is a front view, and Fig. 5(b) is a partial plan view seen from a direction III of Fig. 5(a).

Fig. 6 is a cross-sectional view showing the test apparatus used in Examples 1 and 2.

Fig. 7 is a graph showing the results of the test of Example 1.

Fig. 8 is a view showing a retainer used in the rolling bearing of Comparative Example 2, Fig. 8(a) is a front view, and Fig. 8(b) is a partial plan view seen from the X direction of Fig. 8(a).

Fig. 9 is a graph showing the results of the test of Example 2.

Figure 10 is a cross-sectional view of a prior rolling bearing.

10. . . Holder

11. . . Bag body

12. . . Ring

13. . . Outside the circumference of the ring

14. . . Roller stop

15. . . Convex protrusion

15a. . . Convex protrusion outer peripheral surface

15b. . . Erecting

16. . . Column

Claims (3)

A rolling bearing, comprising: an inner wheel having an inner wheel track on an outer circumferential surface; an outer wheel having an outer wheel track on an inner circumferential surface; and a plurality of rolling bodies rotatably disposed on the inner wheel track and the outer wheel track And a retainer having a plurality of pockets for holding the plurality of rolling elements, wherein the retainer includes: a first annular portion and a second annular portion, which are arranged in an axial direction; and a plurality of The column portion is disposed at a predetermined interval in the circumferential direction so as to connect the first annular portion and the second annular portion, and the first annular portion and the second annular portion have an edge on each outer peripheral surface thereof a plurality of convex protrusions formed in the circumferential direction, wherein the convex protrusion of the second annular portion is formed at a position different from the convex portion of the first annular portion in the circumferential direction, the first circle The convex protrusions of the ring portion and the convex protrusions of the second annular portion are respectively formed at equal intervals in the circumferential direction, and each of the convex protrusions includes an outer peripheral surface of the convex protrusion and a diameter larger than that of the column portion. Large outer perimeter; and one The upright portion is continuous from the circumferential side of the outer peripheral surface of the convex protrusion to the outer peripheral surface of the annular portion, and is guided by the retainer guiding surface formed on the inner peripheral surface of the outer ring The outer peripheral surface of the protrusion. The rolling bearing according to claim 1, wherein the convex projection of the first annular portion and the convex projection of the second annular portion are adjacent to each other in the axial direction The column portion is formed. A spindle device for a machine tool using the rolling bearing of claim 1 or 2.