JP5051445B2 - Rolling bearing device and spindle device - Google Patents

Description

  The present invention relates to a rolling bearing device that is grease-lubricated and a main shaft device including the same.

  As rolling bearing devices that are lubricated only with grease enclosed at the time of assembling the bearing, many proposals such as Patent Document 1 and Patent Document 2 have been proposed. In these bearing devices, in order to extend the life of the bearing, an annular grease reservoir for replenishing grease is provided adjacent to the bearing.

However, in a spindle device such as a horizontal machining center in which the spindle is horizontally arranged, the annular grease reservoir is arranged in a vertical plane (the axial direction is horizontal). For this reason, the replenishing grease sealed in the grease reservoir moves to the lower side of the grease reservoir due to vibration or gravity due to the operation of the main shaft, and further flows out from the lower end of the grease reservoir to the outside. In some cases, sufficient bearing life with respect to the amount of grease could not be obtained. In addition, since the grease moves below the grease reservoir, a large amount of grease flows into the bearing and agitation resistance is generated due to excessive supply of grease. There was also a problem that bearing seizure occurred.
JP 2005-221042 A JP-A-2005-106245

  The present invention has been made in view of such circumstances, suppressing the outflow of the encapsulated grease from below the grease reservoir, obtaining a sufficient bearing life with respect to the encapsulated amount of pre-encapsulated grease, and being stable. It is an object of the present invention to provide a rolling bearing device capable of obtaining a lubrication state and a main shaft device including the rolling bearing device.

(1) A rolling bearing device of the present invention has an inner ring, an outer ring, and a plurality of rolling elements interposed on the raceway surface of the inner and outer rings, the inner ring is a rotating side, the outer ring is a fixed side, and the axial direction is horizontal. And an annular grease reservoir portion that is disposed adjacent to the rolling bearing in the axial direction and that is filled with grease, and opens from the grease reservoir portion to a radial clearance between the outer ring and the inner ring. An annular grease reservoir forming member that forms an opening, and the grease reservoir forming member includes a plurality of partition members that form a divided reservoir portion that divides the annular grease reservoir portion in the circumferential direction. the provided, each of the divided reservoir, comprising a split opening from each of the divided reservoir open to the radial direction gap between the inner ring and the outer ring, position vertically downward side Radial clearance of the divided opening which is characterized that you have been formed to be smaller than the radial clearance of the divided openings located vertically upward.

  According to the present invention, since the annular grease reservoir is divided into a plurality of arc-shaped divided reservoirs by the partition member, the grease other than that supplied to the bearings remains in movement in the respective divided reservoirs. For this reason, even if it flows out, it becomes only the grease enclosed in the division | segmentation accumulation part divided by the perpendicular downward direction. Accordingly, the amount of grease flowing out to the outside can be greatly reduced, and a sufficient bearing life with respect to the amount of grease enclosed in advance can be obtained.

  As described above, the grease remains in the movement within each divided reservoir. In other words, even if the grease moves, it moves below the respective divided reservoirs. In a conventional grease reservoir where no partition member is formed, the grease concentrates on the lower end, so that a large amount of grease temporarily flows into the bearing, resulting in an excessive grease supply state. On the other hand, according to the present invention, the grease is supplied to the bearing space at least from the lower ends of the respective divided reservoir portions. That is, in the circumferential direction of the rolling bearing, the position where the grease is supplied can be dispersed as compared with the conventional one, and as a result, a stable lubrication state of the rolling bearing can be obtained.

(2) In each of the divided openings, the radial gap of the divided opening on the vertically lower side is smaller than the radial gap of the divided opening on the vertically upper side. It is good to be formed.
As described above, the grease sealed in each divided reservoir portion tends to move downward in each divided reservoir portion. Therefore, if the radial clearances of the openings are the same in the circumferential direction, the amount of grease that is replenished from the respective divided reservoirs to the bearing space via the openings is below the divided reservoirs. Therefore, the amount of grease replenished from above becomes larger than the amount of grease replenished from above. On the other hand, according to the present invention, the lower radial gap in the divided opening is formed smaller than the upper radial gap, so that the amount of grease replenished from the divided reservoir to the bearing space through the divided opening. The difference in the circumferential direction can be reduced. Therefore, a stable lubrication state of the rolling bearing can be obtained.
Further, in such a rolling bearing device of the present invention, the radial width of the opening is formed smaller than the radial width of the grease reservoir, and the opening has a diameter larger than the inner peripheral surface of the grease reservoir. It is good to be located outside the direction.

  Thereby, excessive replenishment of the grease sealed in the grease reservoir from the opening to the bearing space (the radial gap between the outer ring and the inner ring) can be suppressed.

In particular, the radial gap of each of the divided openings may be formed so as to gradually decrease from the vertically upper side to the vertically lower side.

  As a result, the amount of grease replenished from the divided reservoir to the bearing space via the divided opening can be made nearly equal in the circumferential direction.

(3) In order to reduce the radial gap of such a divided opening from the vertically upper side toward the vertically lower side, the outer peripheral edge of the opening has a circular shape, and the opening The inner peripheral edge of the outer peripheral edge may be formed in a circular shape eccentric to the vertically lower side with respect to the circular center of the outer peripheral edge.

  Thereby, the grease supply in the circumferential direction as described above can be performed uniformly. And an opening part can be easily formed by setting it as the circular shape which eccentrically made the outer periphery and inner periphery of the opening part eccentric. Furthermore, it is possible to further suppress the outflow of grease from the lower divided reservoir.

(4) The rolling bearing device of the present invention has an inner ring, an outer ring, and a plurality of rolling elements interposed on the raceway surface of the inner and outer rings, the inner ring is a rotating side, the outer ring is a fixed side, and the axial direction is horizontal. And an annular grease reservoir portion that is disposed adjacent to the rolling bearing in the axial direction and is filled with grease, and opens from the grease reservoir portion to a radial clearance between the outer ring and the inner ring. An annular grease reservoir forming member that forms an opening, and the grease reservoir forming member includes a plurality of partition members that form a divided reservoir portion that divides the annular grease reservoir portion in the circumferential direction. the provided, each of the lower end of the dividing reservoir and the bottom of the grease reservoir unit may be positioned at equal intervals in the circumferential direction.

  As described above, in each divided reservoir, the grease tends to move below each divided reservoir. Furthermore, in each divided reservoir, the amount of grease supplied to the bearing gap tends to increase more on the lower side than on the upper side. Therefore, as in the present invention, the lowermost portion of the grease reservoir and the lower end of each of the divided reservoirs are located at equal intervals in the circumferential direction, so that there is a position where the replenishment amount of grease increases in the circumferential direction of the rolling bearing. It will be located at equal intervals. Thereby, a more stable lubrication state of the rolling bearing can be obtained.

( 5 ) The spindle device of the present invention is characterized by including the rolling bearing device according to any one of the above (1) to ( 4 ).

  As a result, it is possible to obtain a spindle device having a sufficient bearing life with respect to the amount of grease enclosed in advance.

  In the rolling bearing device of the present invention, since the annular grease reservoir is divided into a plurality of divided reservoirs by the partition member, the amount of grease flowing out to the outside can be greatly reduced. Therefore, it is possible to obtain a sufficient bearing life with respect to the amount of grease enclosed in advance.

  In addition, the spindle device of the present invention is a spindle device that can extend the life of the bearing device and is excellent in terms of low cost, low noise, energy saving, resource saving, and environment because of grease lubrication.

(First actual machine configuration)
Embodiments of the rolling bearing device of the present invention will be described with reference to FIGS. 1 to 3 by taking as an example a case where it is applied to a spindle device of a horizontal machining center, for example. FIG. 1 is a schematic explanatory diagram of a main part of the spindle device 200. FIG. 2 is a schematic top sectional view of the rolling bearing device 100 according to the first embodiment. FIG. 3 is a front view showing the outer ring spacer 22 fitted with the outer ring spacer mounting member 23 of the first embodiment.

  As shown in FIG. 1, the main shaft device 200 includes a housing 32, a main shaft 31, rolling bearing devices 33 and 34 disposed between the housing and the main shaft, an inner ring fixing nut 39, and an outer ring positioning spacer 40. The outer ring holding lid 41 and the outer ring fixing nut 42 are provided.

  The housing 32 has a substantially cylindrical shape. The housing 32 is obtained by fitting a housing inner cylinder 32a and a housing outer cylinder 32b, and an oil passage groove 43 for cooling is provided in the fitting portion.

  The main shaft 31 is a substantially cylindrical member for transmitting the rotation of the motor 50 to the blade 46 via the holder 45. The main shaft 31 is accommodated in a housing 32 and is rotatably supported with respect to the housing 32 by rolling bearing devices 33 and 34 described later. A clamp unit 47 that clamps the holder 45 to which the cutting tool 46 is fixed is housed in front of the main shaft 31. Further, a push rod 48 for operating the clamp unit 47 is provided. Further, a rotor 50 a of a motor 50 is fixed to a rear end portion of the main shaft 31 via a rotor sleeve 51, and the main shaft 31 is rotationally driven by the motor 50. Reference numeral 52 denotes a stator.

  The rolling bearing devices 33 and 34 are disposed in a radial gap between the housing 32 and the main shaft 31, and support the main shaft 31 so that the main shaft 31 can rotate with respect to the housing 32. Each of the rolling bearing devices 33 and 34 has two bearings as one set, and is arranged as a back surface combination. The inner ring side of the pair of rolling bearing devices 33 and 34 is positioned by an inner ring positioning spacer 37 and is fastened and fixed to the main shaft 31 by an inner ring fixing nut 39. On the other hand, the outer ring side is positioned and fixed in the housing 32 by an outer ring positioning spacer 40, an outer ring holding lid 41 and an outer ring fixing nut 42.

  Hereinafter, the rolling bearing devices 33 and 34 will be described in detail. However, only the part of the rolling bearing device 100 including one bearing among the rolling bearing devices 33 and 34 will be described.

  The rolling bearing device 100 includes a rolling bearing 10, an inner ring spacer 21, an outer ring spacer 22 adjacent to the width surface of the rolling bearing 10, and an outer ring spacer mounting member 23 fitted to the outer ring spacer 22. ing.

  The rolling bearing 10 includes an inner ring 11, an outer ring 12, a plurality of rolling elements 13 interposed between the raceway surfaces of the inner and outer rings 11, 12, and a cage 14 that holds these rolling elements. The rolling bearing 10 is a grease-filled angular ball bearing, and a seal ring 15 is provided on the back side of the bearing so that leakage of grease from the back side of the bearing is prevented.

  An inner ring spacer 21 and an outer ring spacer 22 corresponding to the inner ring 11 and the outer ring 12 are disposed adjacent to each other in the axial direction on the width surface on the front side of the rolling bearing 10. The outer ring spacer 22 is an annular member having a substantially L-shaped cross section having an outer peripheral portion 22 a and a flange portion 22 b adjacent to the width surface of the rolling bearing 10. The outer ring spacer mounting member 23 is fitted so as to abut on the inner diameter surface of the outer peripheral portion 22a of the outer ring spacer 22 and the rear surface of the flange portion 22b.

  The outer ring spacer mounting member 23 includes an abutting portion 23a that abuts against the inner diameter surface of the outer peripheral portion 22a of the outer ring spacer 22 and the rear surface of the flange portion 22b, a groove bottom portion 23b of the outward U-shaped groove portion 24, and the rolling bearing 10. Is an annular member having a standing wall portion 23c exposed at the boundary surface between the outer ring spacer 22 and the inner ring surface of the outer ring spacer 22 and the outer peripheral surface of the groove bottom portion 23b of the outer ring spacer mounting member 23. The groove portion 24 becomes a grease reservoir portion (in FIG. 2, the cross hatched portion is grease, and the depth a of the groove portion 24 corresponds to “the radial width of the grease reservoir portion” in the present invention).

  The outer diameter of the standing wall portion 23 c is formed smaller than the inner diameter of the outer peripheral portion 22 a of the outer ring spacer 22, and the outer diameter of the standing wall portion 23 c is formed larger than the outer diameter of the groove bottom portion 23 b of the outer ring spacer mounting member 23. Yes. That is, the outer peripheral surface of the standing wall portion 23c is located radially inward from the inner peripheral surface of the outer peripheral portion 22a of the outer ring spacer 22 and is radially outward from the outer peripheral surface of the groove bottom portion 23b of the outer ring spacer mounting member 23. To position. An annular gap 25 formed by the outer diameter surface of the standing wall portion 23 c and the inner diameter surface of the outer ring spacer 22 is an opening for supplying grease from the grease reservoir portion 24 into the bearing space 16 of the rolling bearing 10. That is, the outer ring spacer 22 and the outer ring spacer mounting member 23 form a grease reservoir and an opening. And the radial direction width | variety of an opening part is formed smaller than the radial direction width | variety of a grease reservoir part. That is, the outer ring spacer 22 and the outer ring spacer mounting member 23 correspond to the “grease pool forming member” in the present invention.

  As shown in FIG. 3, in this embodiment, four partition members 30 that partition the grease reservoir in the circumferential direction are provided in the annular groove 24 that forms the grease reservoir. 3 indicates the outer diameter surface of the groove bottom 23b (corresponding to the “inner peripheral surface of the grease reservoir” in the present invention). In FIG. 3, by providing the partition member 30, the grease reservoir 24 is divided into four divided reservoirs, that is, an upper region 24a, side regions 24b and 24c, and a lower region 24d, and each divided opening 25a. , 25b, 25c, and 25d open to the bearing space 16.

  The partition member 30 is for preventing the grease from moving to adjacent areas where the grease is partitioned, and may be fixed to such an extent that a desired position can be maintained during operation of the rolling bearing device 100. Accordingly, the shape and material of the partition member 30 are not particularly limited. For example, a resin block having a cross section of the same shape as the grease reservoir 24 may be fitted to a desired position. Further, the steel plate having the same shape may be fixed by welding or the like, or may be formed integrally with the bearing device from the beginning.

  According to the present embodiment, the annular grease reservoir is divided into a plurality of arc-shaped divided reservoirs by the partition member 30, so that the grease other than that supplied to the bearing is in the divided reservoirs. You can only move within the area. Therefore, the amount of grease flowing out to the outside can be greatly reduced. That is, the amount of grease that contributes to replenishment to the rolling bearing 10 increases, and a sufficient bearing life with respect to the amount of grease enclosed in advance can be obtained. Further, excessive supply of grease to the rolling bearing 10 in the lower region 24d can be suppressed, and heat generation due to grease stirring resistance can be reduced.

  The outer ring spacer mounting member 23 is fitted and fixed in a space defined by the outer peripheral portion 22a and the flange portion 22b of the outer ring spacer 22 after grease is sealed in each divided reservoir. Although not shown, a sealing component such as an O-ring may be provided on the inner diameter surface of the adjacent portion between the outer ring spacer 22 and the outer ring 12 in contact with the outer ring spacer 22 in order to prevent grease leakage.

(Second Embodiment)
A rolling bearing device 101 according to a second embodiment will be described with reference to FIG. FIG. 4 is a diagram for explaining the rolling bearing device 101 according to the second embodiment. Specifically, FIG. 4A is a front view showing the outer ring spacer 22 fitted with the outer ring spacer mounting member 23, and FIG. 4B shows an XX cross section of the rolling bearing device 101. FIG. 2 and 3 are denoted by the same reference numerals, and description thereof is omitted.

  As shown in FIG. 3A, the rolling bearing device 101 according to the second embodiment is the same as the rolling bearing device 100 according to the first embodiment, in which the radial gap of the divided opening portion extends from the vertically upper side to the vertically lower side. Specifically, the outer diameter center P of the standing wall portion 23c of the outer ring spacer mounting member 23 (corresponding to “the circular center of the inner peripheral edge of the opening” in the present invention) is formed. ) From the outer diameter center O of the outer ring spacer 22 (corresponding to the “circular center of the outer peripheral edge of the opening” in the present invention) in the vertically downward direction.

  In this way, by dividing the outer diameter center P of the standing wall portion 23c, the size of the divided openings 25a to 25d for supplying grease from the respective divided reservoir portions 24a to 24d into the bearing space 16 is set to the respective divided reservoirs. It can form so that it may become small gradually toward the vertical downward side from the perpendicular | vertical upper side of a part. Thereby, the grease supply in the circumferential direction as described above can be performed uniformly. And an opening part can be easily formed by setting it as the circular shape which eccentrically made the outer periphery and inner periphery of the opening part eccentric. Furthermore, it is possible to further suppress the outflow of grease from the divided divided reservoir 24d below.

(Third embodiment)
A rolling bearing device 102 according to a third embodiment will be described with reference to FIG. FIG. 5 is a diagram illustrating the rolling bearing device 102 according to the third embodiment.

  This rolling bearing device 102 is the same as the rolling bearing device 100 of the first embodiment shown in FIG. 3, but is divided so that the lowermost part of the grease reservoir and the lower ends of the divided reservoirs are located at equal intervals in the circumferential direction. The member 30 is arranged. That is, the partition members 30a, 30b, 30c, and 30d are provided at positions corresponding to the apexes of the regular pentagon with the lowermost end 24B of the grease reservoir 24 as an apex, and the grease reservoir 24 is divided into four divided reservoirs. 24e, 24f, 24g, and 24h.

  In the grease reservoir portion configured in this way, a large amount of the grease sealed in the divided reservoir portion 24e is replenished from above the partition members 30a and 30b. Further, a large amount of the grease in the side divided reservoir portions 24f and 24g is replenished from the vicinity of the upper portion of the partition members 30c and 30d, respectively. In the divided reservoir portion 24h, which is the lower region of the grease reservoir portion, the grease A lot is replenished from.

  Therefore, in the rolling bearing device 102, the positions where the amount of replenishment of grease increases at equal intervals in the circumferential direction of the rolling bearing, and a more stable lubrication state of the rolling bearing can be obtained.

  In addition, this invention is not limited to said embodiment, You may change in the range which does not deviate from the main point of this invention. For example, in the above embodiment, the partition members 30 are provided at four locations, and the grease reservoir is divided into four divided reservoirs. However, the number of partition members 30 installed and the size of the divided reservoirs are the types of rolling bearings. And the diameter of the grease reservoir 24, the amount of grease to be sealed, or the like. The effect of the present invention can be obtained by providing at least two partition members in the horizontal direction and partitioning the grease reservoir 24 into upper and lower arc regions (divided reservoirs). Needless to say, the grease reservoir 24 may be subdivided by providing a larger number of partition members. Moreover, although said embodiment demonstrated the case where the rolling bearing 10 was an angular ball bearing, the rolling bearing 10 can apply a deep groove ball bearing, a cylindrical roller bearing, and other general rolling bearings.

  The present invention is applied to a spindle device of a horizontal machine tool, for example, a machining center, a lathe, a milling machine, a grinding machine, etc., and exhibits a great effect.

It is principal part outline explanatory drawing of a spindle apparatus. It is an upper section schematic diagram of the rolling bearing device of a 1st embodiment. It is a front view which shows the outer ring | wheel spacer which fitted the outer ring | wheel spacer mounting member of 1st Embodiment. It is a figure explaining the rolling bearing apparatus of 2nd Embodiment. (A) is a front view which shows the outer ring | wheel spacer which fitted the outer ring | wheel spacer mounting member. (B) is the schematic which shows the XX cross section of a rolling bearing apparatus. It is a figure explaining the rolling bearing apparatus of 3rd Embodiment.

Explanation of symbols

10: Rolling bearing 11: Inner ring 12: Outer ring 13: Rolling element 21: Inner ring spacer 22: Outer ring spacer (grease pool forming member)
23: Outer ring spacer mounting member (grease reservoir forming member) 23c: Standing wall portion 24: Groove portion (grease reservoir portion) 25: Opening portion (grease replenishing portion) 30: Partition member O: Circular center of the outer peripheral edge of the opening portion P: Circular center of inner peripheral edge of opening 31: Main shaft 32: Housing 33, 34, 100, 101, 102: Rolling bearing device 200: Main shaft device

Claims (5)

A rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements interposed in the raceway surface of the inner and outer rings, wherein the inner ring is a rotation side, the outer ring is a fixed side, and the axial direction is horizontally disposed;
An annular grease reservoir, which is disposed adjacent to the rolling bearing in the axial direction and forms an annular grease reservoir filled with grease, and an opening that opens from the grease reservoir to a radial clearance between the outer ring and the inner ring. A grease reservoir forming member;
In a rolling bearing device comprising:
The grease reservoir forming member includes a plurality of partition members that form divided reservoir portions that divide the annular grease reservoir portion in the circumferential direction ,
Each of the divided reservoirs includes a divided opening that opens from each of the divided reservoirs with respect to a radial clearance between the outer ring and the inner ring.
A rolling bearing device, wherein a radial gap of the divided opening located on the vertically lower side is formed to be smaller than a radial gap of the divided opening located on the vertically upper side.   Each of the divided openings is formed such that, in each of the divided openings, the radial gap of the divided opening on the vertically lower side is smaller than the radial gap of the divided opening on the vertically upper side. The rolling bearing device according to claim 1. The outer periphery of the opening has a circular shape,
3. The rolling bearing device according to claim 1, wherein an inner peripheral edge of the opening has a circular shape that is eccentric to a vertically lower side with respect to a circular center of the outer peripheral edge. A rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements interposed in the raceway surface of the inner and outer rings, wherein the inner ring is a rotation side, the outer ring is a fixed side, and the axial direction is horizontally disposed;
An annular grease reservoir, which is disposed adjacent to the rolling bearing in the axial direction and forms an annular grease reservoir filled with grease, and an opening that opens from the grease reservoir to a radial clearance between the outer ring and the inner ring. A grease reservoir forming member;
In a rolling bearing device comprising:
The grease reservoir forming member includes a plurality of partition members that form divided reservoir portions that divide the annular grease reservoir portion in the circumferential direction,
The rolling bearing device according to claim 1, wherein a lowermost portion of the grease reservoir and a lower end of each of the divided reservoirs are located at equal intervals in the circumferential direction. A spindle device comprising the rolling bearing device according to any one of claims 1 to 4 .