JP2009191876A - Bearing for main spindle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing for a main spindle device having an excellent oil draining characteristic, capable of suppressing excess lubricating oil for a bearing or abnormal heating of the bearing, and preventing wear of a retainer. <P>SOLUTION: Oil draining holes 71a, 71b are formed passing through an outer ring 71 of the bearing 70 for the main spindle device in a radial direction. Circumferential grooves 75a, 75b are formed to communicate with the oil draining holes 71a, 71b on the outer peripheral surface of the outer ring 71. In the retainer 74, the outer ring is guided by an annular part 74a at a position not overlapped on an inner peripheral side opening of the oil draining holes 71a, 71b as viewed from a radial direction. Negative pressure is applied to the inside of the oil draining holes 71a, 71b by suction force of a negative pressure generating device 103. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a spindle device bearing, and more particularly to a spindle device bearing that can be applied to a multi-axis control machine tool or the like and is supplied with lubricating oil from the outside and can rotate at high speed.

  For example, in a multi-axis controlled machine tool such as a 5-axis machine or a multi-task machine tool, the rotary shaft to which the tool is attached can turn between a horizontal position and a vertical position or 360 degrees. A tilt type spindle device is used.

  In such a spindle device, as a method of lubricating a bearing disposed inside, an oil-air lubrication method or an oil mist lubrication method that supplies a small amount of lubricating oil from the outside to the inside of the bearing using air, or a lubricating oil A direct injection method is employed in which the nozzle is directly injected into the bearing intermittently at a high speed.

For example, in oil-air lubrication or oil mist lubrication, as shown in FIG. 18, the lubricating oil is supplied from the nozzle 901 to the bearing 900, and from the oil drain holes 903a and the oil drain grooves 903b formed in the outer ring 900a and the spacer 902. A structure in which the oil is discharged to the outside through an oil drain passage 905 of the housing 904 is known (see, for example, Patent Document 1).
Japanese Utility Model Publication No. 63-139324 (FIG. 3)

  By the way, in the spindle device bearing described in Patent Document 1, the lubricating oil is naturally drained through the oil draining passage 905 of the housing 904 by the action of gravity, but for lubrication inside and around the bearing. There is a possibility that the used lubricating oil cannot be discharged completely. In particular, in a spindle device capable of high-speed rotation with dm · N 500,000 or more, and dm · N 1,000,000 or more, where the amount of residual oil in the bearing is sensitive to lubrication conditions, excessive heat generation and excessive stirring oil can cause abnormal heat generation. There is sex. In addition, when applied to a tilt type spindle device, the lubricating oil discharged into the oil drain hole 903a or the oil drain groove 903b is returned to the inside of the bearing due to a change in the posture of the spindle device, resulting in excessive lubricating oil or stirring resistance. May cause abnormal heat generation.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to have a good oil drainage property and to prevent excessive lubrication oil and abnormal heat generation of the bearing and prevent wear of the cage. It is an object of the present invention to provide a bearing for a main shaft device.

The above object of the present invention is achieved by the following configurations.
(1) an inner ring having an inner ring raceway surface on the outer peripheral surface;
An outer ring having an outer ring raceway surface on the inner circumferential surface;
A plurality of rolling elements disposed between the inner ring raceway surface and the outer ring raceway surface;
A cage that holds the plurality of rolling elements in a freely rollable manner;
A bearing for a spindle device that rotatably supports a rotating shaft with respect to a housing and is lubricated by oil lubrication,
An oil drainage hole is formed in the outer ring in the radial direction, and a negative pressure is applied to the oil drainage hole by a suction force from the outside of the bearing.
A bearing for a main shaft device, wherein the retainer is guided by an outer ring at an outer peripheral surface at a position where it does not overlap with an inner peripheral side opening of the oil drainage hole when viewed in the radial direction.
(2) The spindle device bearing is an angular ball bearing in which a ball has a contact angle and is disposed between the outer ring raceway surface and the inner ring raceway surface,
The oil drain hole formed on the counter-bore side of the outer ring is spaced outward in the axial direction from the intersection of an imaginary line formed by the contact angle and the outer peripheral surface of the outer ring that passes through the center of the ball. The spindle device bearing according to (1), wherein the spindle device bearing is formed at a position.
(3) The main shaft device bearing is a cylindrical roller bearing in which a cylindrical roller is disposed between the outer ring raceway surface and the inner ring raceway surface, and the inner ring has a pair of flange portions on both axial sides of the inner ring raceway surface. And
The bearing for a spindle apparatus according to (1), wherein an oil supply hole for supplying the lubricating oil is further formed in the outer ring in a radial direction.

  According to the spindle device bearing of the present invention, since negative pressure is applied to the oil drainage hole formed in the outer ring by the suction force from the outside of the bearing, excess lubricating oil inside the bearing is passed through the oil drainage hole. Can be discharged quickly. In particular, in the tilt type spindle device, even if the posture changes, the lubricating oil in the drainage hole that should be discharged is prevented from returning to the raceway surface, and excessive lubricating oil and abnormal heat generation are suppressed. be able to.

  In addition, the cage is guided by the outer ring by the outer circumferential surface at a position that does not overlap with the inner circumferential side opening of the oil drainage hole when viewed from the radial direction, so the outer ring guide surface of the cage and the inner circumferential side opening of the oil drainage hole Thus, the wear of the cage, particularly the outer ring guide surface, can be suppressed and the life of the bearing can be extended.

  Further, in the angular ball bearing, the oil drain hole formed on the counter-bore side of the outer ring is located outward in the axial direction from the intersection of the virtual line passing through the center of the ball formed by the contact angle and the outer peripheral surface of the outer ring. Since it is formed at a distant position, it is possible to prevent the force acting on the outer ring from being applied to the thinned portion due to the formation of the oil drainage hole, and to suppress a decrease in rigidity of the angular ball bearing.

  In addition, in cylindrical roller bearings, in addition to the oil drainage hole, the outer ring is formed with a lubrication hole in the radial direction so that there is no need to provide a separate nozzle outside the bearing. With a simple configuration, lubricating oil can be supplied into the bearing.

(First embodiment)
Hereinafter, a spindle device for machine tools according to a first embodiment of the present invention will be described in detail based on the drawings.

  FIG. 1 shows a portal machining center as a multi-tasking machine tool in which a spindle device having a bearing of this embodiment is incorporated. In the portal machining center 1, a table 3 is supported on a bed 2 so as to be movable in the X-axis direction, and a pair of columns 4 are erected on both sides of the bed 2. A cross rail 5 is installed on the upper end of the column 4, and a saddle 6 is provided on the cross rail 5 so as to be movable in the Y-axis direction. The saddle 6 supports a ram 7 that can be moved up and down in the Z-axis direction. A spindle that holds the spindle device 20 at the lower end of the ram 7 so as to be capable of rotational indexing around the Y axis and the Z axis. A head 8 is attached.

  The spindle head 8 is provided with a pair of support arms 9 so as to sandwich the bracket 21 of the spindle device 20. The pair of support arms 9 has a pair of swivel shafts (not shown) fixed to both side surfaces of the bracket 21. Support for rotation. Thus, the spindle device 20 can be swiveled around the Y axis with respect to the pair of support arms 9 by a drive mechanism (not shown) provided on the spindle head 8 side, and between the horizontal position and the vertical position, or 360 A tilt type capable of changing the mounting posture over the entire range is constructed.

  As shown in FIG. 2, the spindle device 20 is a motor built-in system, and a hollow rotary shaft 22 is provided at the axial center, and a draw bar 23 slides on the axis of the rotary shaft 22. It is freely inserted. The draw bar 23 urges the pull stud 25 attached to the tool holder 24 in the counter tool side direction (right direction in the figure) by the force of the disc spring 27 via the clamp ball 26. It fits with the tapered surface 28 of the rotating shaft 22. A tool (not shown) is attached to the tool holder 24. As a result, the rotary shaft 22 clamps the tool at one end (the left side in the figure) so that the tool can be attached.

  The rotary shaft 22 is fixed to the bracket 21 (see FIG. 1) by two rows of front bearings 60 and 70 that support the tool side and a row of rear bearings 80 that support the opposite tool side. Further, the outer cylinder 29 constituting the housing H is rotatably supported. The front bearings 60 and 70 and the rear bearing 80 constitute the spindle device bearing of the present embodiment.

  On the outer peripheral surface of the rotary shaft 22 between the front bearings 60 and 70 and the rear bearing 80, a rotor sleeve 31 on which the rotor 30 is shrink-fitted is fitted. The stator 32 disposed around the rotor 30 is fixed to the outer cylinder 29 by fitting a cooling jacket 33 shrink-fitted into the stator 32 into the outer cylinder 29. Therefore, the rotor 30 and the stator 32 constitute a motor, and by supplying electric power to the stator 32, a rotational force is generated in the rotor 30 and the rotating shaft 22 is rotated.

  Further, a tool unclamp cylinder 36 constituting the housing H in which a tool unclamp piston 35 is slidably fitted is fixed to the rear cover 34 constituting the housing H fixed to the outer cylinder 29 and the non-tool side. ing. Therefore, when exchanging the tool, the hydraulic oil is guided from the oil passage 37 to the hydraulic chamber 38 and the tool unclamp piston 35 is advanced to the tool side (left side in the figure), so that the drawbar 23 is moved to the tool side (in the figure). Advance to the left) to unclamp the tool.

  The front bearings 60, 70 are outer rings 61, 71, inner rings 62, 72, balls 63, 73 as rolling elements arranged with contact angles, and outer ring guides that hold the balls 63, 73 at substantially equal intervals. Angular contact ball bearings each having a cage 64, 74, which are arranged in a rear combination. The rear bearing 80 is a cylindrical roller bearing having an outer ring 81, an inner ring 82, a cylindrical roller 83 as a rolling element, and an outer ring guide retainer 84 that holds the cylindrical roller 83 at substantially equal intervals.

  The outer rings 61 and 71 of the front bearings 60 and 70 are fitted in the outer cylinder 29 and are attached to the outer cylinder 29 via the outer ring spacer 40 with a nozzle by a front bearing outer ring presser 39 bolted to the outer cylinder 29. It is fixed in the axial direction. Further, the inner rings 62 and 72 of the front bearings 60 and 70 are fitted on the rotating shaft 22 and are axially connected to the rotating shaft 22 via the inner ring spacer 42 by the nut 41 fastened to the rotating shaft 22. It is fixed.

  An outer ring 81 of the rear bearing 80 is fitted in the rear lid 34 and is fixed to the rear lid 34 by a rear bearing outer ring presser 43 that is bolted to the rear lid 34. The inner ring 82 of the rear bearing 80 is taper-fitted to a tapered surface 44 formed on the rotating shaft 22, and the other ring 45 fastened to the rotating shaft 22 is used to cover the inner ring spacer 46 and the speed sensor 47. Positioning is performed via the detection unit 48.

  Note that a detection unit 49 of the speed sensor 47 is fixed to a position opposite to the detection unit 48 in the radial direction on the side opposite to the tool of the rear bearing outer ring presser 43 and detects the rotation speed of the rotary shaft 22. A front cover 50 is bolted to the tool side end surface of the front bearing outer ring presser 39.

  Here, as shown in FIGS. 2 to 4, the outer cylinder 29, the rear lid 34, and the tool unclamping cylinder 36 constituting the housing H are used for lubricating the front bearings 60 and 70 and the rear bearing 80, respectively. A plurality of oil supply passages (oil supply holes in the housing H) 90, 91, 92 are formed, and a lubrication device 93 that feeds the lubricant oil is provided to one end side of these passages 90, 91, 92 via a pipe (not shown). Each is attached. The lubrication system supplied by the lubrication device 93 may be oil lubrication, and may be any of oil-air lubrication, oil mist lubrication, direct injection lubrication, and the like.

  For example, in the case of oil-air lubrication, the other end sides of the oil supply passages 90, 91, 92 are provided with nozzles 40a (see FIG. 2), 40b (see FIG. 3) formed in the outer ring spacer 40, and rear bearing outer ring pressers. The nozzle 43a (see FIG. 4) formed in the nozzle 43 communicates with the lubricating oil sent by the lubricating device 93 from the side of each bearing 60, 70, 80 into the bearing space.

  Further, the housing H has a plurality of discharge passages (drain holes for the housing H) 100 (see FIG. 2) and 101 (see FIG. 3) through which the lubricating oil that lubricates the bearings 60, 70, and 80 is discharged. ), 102 (see FIG. 4) are formed, and negative pressure generators 103 for sucking lubricating oil are respectively connected to one end sides of these passages 100, 101, 102 via pipes (not shown). ing.

  Specifically, as shown in an enlarged view in FIG. 5, in the front bearing 70, a plurality of balls 73 are formed in a substantially arc-shaped outer ring raceway surface 71 c formed on the inner circumferential surface of the outer ring 71 and an outer circumferential surface of the inner ring 72. And a substantially arc-shaped inner ring raceway surface 72a formed with a contact angle with respect to the radial direction. The outer ring 71 of the front bearing 70 has an oil drain hole 71a that opens in the vicinity of the outer ring raceway surface 71c through which the balls 73 pass on the inner peripheral surface of the counter bore side and the counter counter side, and penetrates in the radial direction. , 71b are formed in a plurality at regular intervals in the circumferential direction. On the inner peripheral surface of the outer ring 71, oil collecting grooves 77a and 77b are formed in the circumferential direction at axial positions where the oil drain holes 71a and 71b are opened. Further, annular circumferential grooves 75a and 75b in which the oil drain holes 71a and 71b are respectively opened are formed on the outer peripheral surface of the outer ring 71. The circumferential grooves 75a and 75b are formed in the oil drain holes 71a and 71b, respectively. 71b and oil drain holes 29a and 29b of the oil drain passage 101 formed in the outer cylinder 29 are communicated with each other. The oil collecting grooves 77a and 77b formed in the inner peripheral side openings of the oil drain holes 71a and 71b are preferably opened in the vicinity of the outer ring raceway surface 71c as shown in FIG. Furthermore, it is more preferable that the oil collecting grooves 77a and 77b are respectively formed at positions that overlap with the balls 73 when viewed from the radial direction. As a result, there is a merit that after the rolling contact portion is lubricated, the oil adhering to the balls 73 is shaken off by the centrifugal force and then directly guided to the oil collecting grooves 77a and 77b. However, the oil collecting grooves 77a and 77b are not limited to positions that overlap with the balls 73 when viewed from the radial direction.

  The retainer 74 is an outer ring guide retainer that retains the balls 73 at substantially equal intervals, and is formed to be substantially line symmetrical in the axial direction. The cage 74 includes a pair of annular portions 74a and 74b located on both sides in the axial direction, and a plurality of column portions 74c that connect the annular portions 74a and 74b and are arranged at substantially equal intervals in the circumferential direction. The ring portions 74a and 74b and the adjacent column portion 73c constitute a pocket for holding the ball 73. Further, the retainer 74 has a clearance portion by setting the inner peripheral portion of the outer peripheral surface of the column portion 74c and the outer peripheral surfaces of the annular portions 74a and 74b to be smaller in diameter than the outer portion of the outer peripheral surface of the annular portions 74a and 74b. 74d is formed. As a result, the retainer 74 is configured such that, on the counter-bore side, the outer portion of the outer peripheral surface of the annular portion 74a and the inner peripheral surface 71f of the outer ring 71 are viewed from the radial direction of the oil collection groove 77a of the oil drain hole 71a. The outer ring is guided by sliding contact at a position where it does not overlap.

  Therefore, the annular portion 74a, which is the guide surface of the cage 74, is not scraped by the opening edge of the oil collecting groove 77a, and wear of the cage 74 is prevented. The front bearing 60 has the same configuration as that of the front bearing 70 arranged in combination with the front bearing 70 and the back surface, and thus the description thereof is omitted.

  Further, in the angular ball bearing 70 shown in FIG. 5, the oil supply direction is performed from the rear side. However, as in the modification shown in FIG. It may be done from.

  Further, as shown in FIG. 7, as with the front bearings 60 and 70, the rear bearing 80 also includes an outer ring raceway surface 81 c formed on the inner circumferential surface of the outer ring 81 and the outer circumference of the inner ring 82. It is arranged between the inner ring raceway surface 82a formed on the surface. The inner ring 82 has a pair of flange portions 82b on both sides in the axial direction of the inner ring raceway surface 82a. A plurality of oil drain holes 81a and 81b penetrating in the radial direction are provided at substantially equal intervals in the circumferential direction in the vicinity of the outer ring raceway surface 81c at a position not interfering with the cylindrical roller 83 on the inner circumferential surfaces on both axial sides of the outer ring 81. It is formed one by one. Oil collecting grooves 87a and 87b are formed on the inner circumferential surface of the outer ring 81 in the circumferential direction at axial positions where the oil drain holes 81a and 81b are opened. Further, annular circumferential grooves 85a and 85b in which the oil drain holes 81a and 81b are respectively opened are formed on the outer peripheral surface of the outer ring 81. The circumferential grooves 85a and 85b are formed by the oil drain holes 81a and 85b. 81 b communicates with oil drain holes 34 a and 34 b of the oil drain passage 102 formed in the rear lid 34.

  The retainer 84 is also an outer ring guide retainer that retains the cylindrical rollers 83 at substantially equal intervals, and is formed substantially in line symmetry in the axial direction. The cage 84 includes a pair of annular portions 84a and 84b located on both sides in the axial direction, and a plurality of column portions 84c that connect the annular portions 84a and 84b and are arranged at substantially equal intervals in the circumferential direction. These annular portions 84a and 84b and the adjacent column portion 83c constitute a pocket for holding the cylindrical roller 83. Further, the retainer 84 has a clearance portion by making the inner part of the outer peripheral surface of the column part 84c and the outer peripheral surface of both annular parts 84a, 84b smaller than the outer part of the outer peripheral surface of the annular parts 84a, 84b. 84d is formed.

  As a result, the retainer 84 has an outer portion of the outer peripheral surface of the annular portions 84a and 84b and an inner peripheral surface 81f of the outer ring 81 as viewed from the radial direction of the oil collection grooves 87a and 87b of the oil drain holes 81a and 81b. The outer ring is guided by a sliding contact at a position where the oil collecting grooves 87a and 87b are not overlapped, that is, outside the oil collecting grooves 87a and 87b. Therefore, the annular portions 84a and 84b which are guide surfaces of the cage 84 are not scraped by the opening edge portions of the oil collecting grooves 87a and 87b, and wear of the cage 84 is prevented.

  Moreover, in this embodiment, what is shown to Fig.8 (a)-FIG.8 (h) is mentioned as an oil supply direction and oil supply position to the cylindrical roller bearing which is the rear side bearing 80. FIG. Specifically, as shown in FIG. 8A, refueling may be performed from the tool side toward the outer peripheral surface of the inner ring 82 and the inner peripheral surface of the cage 84. Moreover, as shown in FIG.8 (b), oil supply may be performed from the tool side toward the inner peripheral surface of the outer ring | wheel 81, and the outer peripheral surface of the holder | retainer 84. FIG. Further, as shown in FIG. 8C, the refueling may be performed from the side opposite to the tool between the outer peripheral surface of the inner ring 82 and the inner peripheral surface of the cage 84, as shown in FIG. As shown in FIG. 6, the process may be performed from the side opposite to the tool toward the inner peripheral surface of the outer ring 81 and the outer peripheral surface of the cage 84.

  Further, as shown in FIG. 8 (e), the lubrication is performed between the outer peripheral surface of the inner ring 82 and the inner peripheral surface of the cage 84, and between the inner peripheral surface of the outer ring 81 and the outer peripheral surface of the cage 84. You may carry out from the tool side toward two places. Moreover, as shown in FIG.8 (f), oil supply may be performed from both the tool side and the non-tool side toward the outer peripheral surface of the inner ring | wheel 82, and the inner peripheral surface of the holder | retainer 84, As shown in FIG. 8G, it may be performed from both the tool side and the counter tool side toward the inner peripheral surface of the outer ring 81 and the outer peripheral surface of the cage 84. In addition, as shown in FIG. 8 (h), the oil supply is performed between the outer peripheral surface of the inner ring 82 and the inner peripheral surface of the cage 84, and between the inner peripheral surface of the outer ring 81 and the outer peripheral surface of the cage 84. It may be performed from the side opposite to the tool toward the two locations. In addition, the oil supply direction and the oil supply position to the angular ball bearings which are the front bearings 60 and 70 can be supplied from the outside in the axial direction of the bearing similarly to the cylindrical roller bearing. Moreover, the phase of each oil supply may be the same phase, and may be different phases.

  As shown in FIG. 9, when the oil drainage hole 81a is formed only on one side in the axial direction, from the viewpoint of oil drainage, the lubricating oil is supplied to the cylindrical roller 83 (indicated by an arrow in the figure). ) And the other side. Also in this case, a circumferential groove 85a and an oil collecting groove 87a are formed at positions where the oil drain holes 81a open to the outer peripheral surface and the inner peripheral surface.

  Accordingly, the lubricating oil in the oil drain holes 71a, 71b, 81a, 81b, which lubricated the bearings 60, 70, 80, is connected to the circumferential grooves 75a, 75b, 85a, 85b and the oil drain passages 100, 101, 102. It is discharged to the outside through. At this time, negative pressure acts in the oil drain holes 71a, 71b, 81a, 81b by the suction force from the outside of the bearing, that is, the suction force of the negative pressure generator 103, and the oil drain holes 71a, 71b, 81a. , 81b is forcibly sucked. Also, the lubricating oil adhering to the inner peripheral surfaces of the outer rings 61, 71, 81 near the outer ring raceway surfaces 71 c, 81 c due to the suction force of the negative pressure generator 103 is also discharged by the suction force of the negative pressure generator 103. Guided to oil holes 71a, 71b, 81a, 81b.

  Thereby, excess lubricating oil can be quickly discharged from the oil drain holes 71a, 71b, 81a, 81b provided in the vicinity of the outer ring raceway surfaces 71c, 81c of the bearings 60, 70, 80. In particular, in the tilt-type main spindle device 20 as in the present embodiment, even when the posture changes, the lubricating oil that should be discharged returns to the inside of the bearing, in particular, the oil drain holes 71a, 71b, The lubricating oil present in 81a and 81b is prevented from returning to the outer ring raceway surfaces 71c and 81c, and abnormal heat generation due to excessive lubricating oil and stirring resistance can be suppressed.

  Further, in the cages 74, 84, the outer peripheral surfaces of the annular portions 74a, 84a, 84b are positioned at the inner peripheral surfaces 71f, 81f of the outer rings 71, 81 and the inner peripheral side openings of the oil drain holes 71a, 81a, 81b. The oil collecting grooves 77a, 87a, 87b are slidably contacted with each other at a position where they do not overlap when viewed from the radial direction, and are guided by the outer ring, so that the annular portions 74a, 84a, 84b of the cages 74, 84 are connected to the oil collecting grooves 77a, It is possible to prevent contact with the opening edge portions of 87a and 87b, thereby suppressing wear of the cages 74 and 84, particularly the annular portions 74a, 84a and 84b, and the life of the bearings 60, 70 and 80. Can be extended.

  In addition, circumferential grooves 75a, 75b, 85a, 85b communicating the oil drain holes 71a, 71b, 81a, 81b and the oil drain passages 100, 101, 102 of the housing H are formed on the outer peripheral surfaces of the outer rings 61, 71, 81. Therefore, the bearings 60, 70, 80 can be assembled to the housing H without performing phase alignment with the oil drain passages 100, 101, 102, and the assemblability of the spindle device 20 is improved.

  Further, oil collecting grooves 77a, 77b, 87a, 87b are formed on the inner peripheral surfaces of the outer rings 61, 71, 81 in the circumferential direction at axial positions where the oil drain holes 71a, 71b, 81a, 81b are opened. Therefore, the lubricating oil that adheres to the inner peripheral surfaces of the outer rings 61, 71, 81 and lubricates the bearings is collected in the oil collecting grooves 77a, 77b, 87a, 87b, and the oil collecting grooves 77a, 77b, 87a, 87b This lubricating oil is quickly discharged into the oil drain holes 71a, 71b, 81a, 81b by the negative pressure generator 103.

  When the bearings 60, 70, and 80 are rotating at high speed, the internal air also rotates in the same manner due to its viscous resistance when the balls 63 and 73 and the cylindrical roller 83 revolve, and when the cage 74 and the inner ring 72 rotate. The circumferential air flow is generated. Therefore, the oil adhering to the inner peripheral surfaces of the outer rings 61, 71, 81 is also moved in the circumferential direction along the inner peripheral surface. In particular, when the rotary shaft 22 is a vertical shaft, the oil movement is likely to occur because the gravity effect is small. Therefore, if there are the oil collecting grooves 77a, 77b, 87a, 87b, the oil is easily collected in the oil collecting grooves 77a, 77b, 87a, 87b, and the oil drainage is improved. Accordingly, the oil collecting grooves 77a, 77b, 87a, 87b may be any of a square cross section, an arc shape, and a taper shape, but an arc shape is more preferable than a square shape.

  In the present embodiment, the oil drain passages 100, 101, 102 are formed for each of the bearings 60, 70, 80, so that the bearings 60 can be changed by changing the suction capacity condition of the negative pressure generator 103. , 70, 80 can be optimized.

(Second Embodiment)
Next, the spindle device bearing according to the second embodiment of the present invention will be described in detail with reference to FIG. In addition, in this embodiment, the structure of the angular ball bearing which is a front side bearing differs from 1st Embodiment. For this reason, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.
Further, in each embodiment relating to the angular ball bearing described below, among the double-row front bearings, the angular ball bearing on the counter tool side is described, and the angular ball bearing on the tool side has the same configuration. Description is omitted.

  As shown in FIG. 10, the outer ring 171 of the angular ball bearing 170 of the present embodiment opens near the outer ring raceway surface 71c through which the ball 73 passes on the inner peripheral surface of the counter bore side and the counter counter side, Further, a plurality of oil drain holes 171a and 71b penetrating in the radial direction are formed at substantially equal intervals in the circumferential direction. The oil drainage hole 171a formed on the counter-bore side is located away from the intersection point P between the virtual line L formed by the contact angle and the outer peripheral surface of the outer ring 171 passing through the center O of the ball 73 in the axial direction. Is formed. Thereby, an inner peripheral surface 171f having a relatively wide width is formed between the outer ring raceway surface 71c of the outer ring 171 and the oil drain hole 171a.

  Further, circumferential grooves 75a and 75b in which the oil drain holes 171a and 71b are opened are formed on the outer peripheral surface of the outer ring 171, and the inner peripheral surface is circumferentially positioned at an axial position where the oil drain holes 171a and 71b are opened. An annular oil collecting groove 177a, 77b is formed across the direction. Further, the circumferential grooves 75 a and 75 b communicate the oil drain holes 171 a and 71 b with the oil drain holes 29 a and 29 b of the oil drain passage 101.

  The cage 174 includes a pair of annular portions 174a and 174b located on both sides in the axial direction, and a plurality of column portions 174c that connect the annular portions 174a and 174b and are arranged at substantially equal intervals in the circumferential direction. The annular portion 174a, 174b and the adjacent pillar portion 174c constitute a pocket for holding the ball 73. The annular portions 174a and 174b and the column portion 174c have a substantially uniform thickness. The axial width of the cage 174 is narrower than that of the cage 74 of the first embodiment. That is, the retainer 174 has an outer peripheral surface of the annular portion 174a that does not overlap with the oil collecting groove 177a of the oil drain hole 171a when viewed from the radial direction, that is, is positioned on the inner side in the axial direction of the oil collecting groove 177a The outer ring is guided by sliding contact with an inner peripheral surface 171f formed between the raceway surface 71c and the oil drain hole 171a.

Therefore, in this embodiment, the oil draining hole 171a on the counter-counter bore side passes through the center O of the ball 73 and is axially outward from the intersection P between the virtual line L formed by the contact angle and the outer peripheral surface of the outer ring 171. Therefore, the force acting on the outer ring 171 by being incorporated in the spindle device 20 is prevented from being applied to the thinned portion due to the formation of the oil drain hole 171a. Can be suppressed. Further, since the annular portion 174a serving as the guide surface of the cage 174 is not scraped by the opening edge portion of the oil collecting groove 177a, wear of the cage 174 is prevented.
Other configurations and operations are the same as those in the first embodiment.

(Third embodiment)
Next, a spindle device bearing according to a third embodiment of the present invention will be described in detail with reference to FIG. In addition, in this embodiment, the structure of the angular ball bearing which is a front side bearing differs from 1st and 2nd embodiment. Therefore, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and the description thereof is omitted or simplified.

  As shown in FIG. 11 (a), the outer ring 271 of the angular ball bearing 270 of the present embodiment is opened in the vicinity of the outer ring raceway surface 71c through which the ball 73 passes on the inner peripheral surface of the counter bore side and the counter counter side. In addition, a plurality of oil drain holes 271a and 71b penetrating in the radial direction are formed at substantially equal intervals in the circumferential direction. These oil drain holes 271a and 71b are formed at positions that overlap with the balls 73 when viewed from the radial direction.

  On the outer peripheral surface of the outer ring 271, circumferential grooves 75a and 75b in which oil drain holes 271a and 71b are opened are formed. Further, on the inner peripheral surface of the outer ring 271 on the counter bore side, an annular oil collecting groove 77b having a substantially arc-shaped cross section is formed in the circumferential direction at an axial position where the oil drain hole 71b is opened, as in the above embodiment. Has been. On the other hand, an annular oil collecting groove 277a provided on the inner peripheral surface of the outer ring 271 on the counter-bore side at the axial position where the oil drain hole 271a opens is larger in diameter than the inner peripheral surface 271f guiding the retainer 74. It has a square cross section with an inner peripheral surface.

As in the first embodiment, the retainer 74 has a relief portion 74d. On the counter-counter bore side, the outer portion of the outer peripheral surface of the annular portion 74a and the inner peripheral surface 271f of the outer ring 271 are in the radial direction. The outer ring is guided at a position where it does not overlap with the oil drain hole 271a as viewed from the top. As a result, the annular portion 74a, which is the guide surface of the retainer 74, is not scraped by the opening edge of the oil collecting groove 277a, and wear is prevented.
Other configurations and operations are the same as those in the first and second embodiments.

  FIG. 11B shows a modification of the present embodiment. In this modified example, in the cage 274, the annular portions 274a and 274b and the column portion 274c have a substantially uniform thickness, and are formed substantially line-symmetric in the axial direction. An annular relief groove 274d is formed on the outer peripheral surface of the annular portion 274a that faces the opening edge of the oil collecting groove 277a. As a result, the cage 274 does not overlap the oil drain hole 271a when viewed from the radial direction, that is, the outer peripheral surface of the annular portion 274a axially outside the escape groove 274d, and the inner peripheral surface 271f of the outer ring 271. Guided. Therefore, according to this modification, wear of the cage 274 can be prevented by providing the escape groove 274d on the outer peripheral surface of the annular portion 274a instead of the escape portion. In consideration of symmetry, the cage 274 is also formed with an annular relief groove 274d on the outer peripheral surface of the annular portion 274b.

(Fourth embodiment)
Next, a spindle device bearing according to a fourth embodiment of the present invention will be described in detail with reference to FIG. In addition, in this embodiment, in the structure of the angular ball bearing which is a front side bearing, it differs from 1st-3rd embodiment. Therefore, about the equivalent part to 1st-3rd embodiment, the same code | symbol is attached | subjected and description is abbreviate | omitted or simplified.

  As shown in FIG. 12, in the front bearing 370, the cage 374 is guided by the outer ring on both sides of the ball 73. The outer ring 371 has an inner peripheral surface 371f1 that is radially opposed to the counter bore surface 72b of the inner ring 72 on the inner peripheral surfaces on both sides of the outer ring raceway surface 71c. The outer ring 371 has a smaller diameter than the inner peripheral surface 371f2 opposite to the outer ring raceway surface 71c. Each inner peripheral surface 371f1, 371f2 has a substantially uniform inner diameter. Similarly to the above embodiment, oil collecting grooves 77a and 77b are opened on the respective inner peripheral surfaces 371f1 and 371f2 of the outer ring 371, and the oil collecting grooves 77a and 77b are respectively provided with oil drain holes 71a and 71b, It communicates with the direction grooves 75a and 75b.

The retainer 374 connects the small-diameter side annular part 374a and the large-diameter side annular part 374b, which are located on both sides in the axial direction and have different outer diameters, to the annular part 374a, 374b, and is substantially in the circumferential direction. A plurality of pillar portions 374c arranged at equal intervals, and these annular portions 374a, 374b and the adjacent pillar portion 373c constitute a pocket for holding the ball 73. In addition, the cage 374 forms a relief portion 374d on the outer peripheral surface of the column portion 374c and the inner portions of the outer peripheral surfaces of both annular portions 374a and 374b. The relief portion 374d has a step shape on the outer peripheral surface of the column portion 374c according to the inner peripheral surfaces 371f1 and 371f2 of the outer ring 371, and the inner portion of the outer peripheral surface of the small-diameter annular portion 374a is smaller than the outer portion thereof. The inner portion of the outer peripheral surface of the large-diameter annular portion 374b is also formed with a smaller diameter than the outer portion. As a result, the retainer 374 has the oil collecting holes 71a and 71b in the outer peripheral surfaces of the annular portions 374a and 374b and the inner peripheral surfaces 371f1 and 371f2 of the outer ring 371 on the inner peripheral surfaces on both sides. The outer ring is guided by sliding contact with the grooves 77a and 77b at a position where they do not overlap when viewed from the radial direction.
In addition, about another structure and effect | action, it is the same as that of the thing of 1st-3rd embodiment. Further, in the cage that guides the outer ring on both sides of the ball, the outer diameter of the pair of annular portions may have the same dimension, and the inner diameter of each inner circumferential surface on both sides of the cylindrical roller of the outer ring may have the same dimension.

(Fifth embodiment)
Next, a bearing for a spindle device according to a fifth embodiment of the present invention will be described in detail with reference to FIG. In this embodiment, the configuration of the cylindrical roller bearing which is the rear bearing is different from that of the first embodiment. For this reason, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  As shown in FIG. 13A, in the cylindrical roller bearing 180 of the present embodiment, the shape of the cage 184 is different from that of the first embodiment. That is, this retainer 184 has a pair of annular portions 184a and 184b and a plurality of column portions 184c, as in the first embodiment, but is provided on the side for supplying lubricating oil to the cylindrical rollers 83 (see FIG. The outer ring is guided by one annular portion 184a located on the same side as that indicated by the middle arrow). That is, the relief portion 184d is formed across the inner portion of the outer peripheral surface of one annular portion 184a, the outer peripheral surface of the column portion 184c, and the outer peripheral surface of the other annular portion 184b. Further, in the one annular portion 184a, the inner circumferential surface of the outer ring 81 is a position that does not overlap the oil drainage hole 81a when viewed from the radial direction, in other words, a portion that is located on the axially outer side from the oil drainage hole 81a. Guided to 81f.

Therefore, also in this embodiment, since the outer peripheral surface of the annular portion 184a which is the guide surface of the cage 184 is not scraped by the opening edge portion of the oil collecting groove 87a, wear of the cage 184 is prevented. . Further, since the cage 184 is guided by the outer ring by the annular portion 184a located on the same side as the oil supply side, the oil supplied is reliably lubricated not only to the cylindrical roller 83 but also to the guide surface.
Other configurations and operations are the same as those in the first embodiment.

  13B, when the oil drain hole 81b is formed only on one side in the axial direction, the oil drain hole 81b is in relation to the cylindrical roller 83 from the viewpoint of oil drainage. It is formed on the side opposite to the side (indicated by an arrow in the figure) for supplying the lubricating oil. Also in this case, a circumferential groove 85a and an oil collecting groove 87a are formed at positions where the oil drain holes 81a open to the outer peripheral surface and the inner peripheral surface.

(Sixth embodiment)
Next, a spindle device bearing according to a sixth embodiment of the present invention will be described in detail with reference to FIG. In the present embodiment, the configuration of the cylindrical roller bearing which is the rear bearing is different from the first and fifth embodiments. Therefore, portions equivalent to those in the first and fifth embodiments are denoted by the same reference numerals, and description thereof is omitted or simplified.

  As shown in FIG. 14A, in the cylindrical roller bearing 280 of the present embodiment, the oil supply is performed through an oil supply hole 285 formed in the outer ring 281 so as to penetrate in the radial direction. Specifically, the oil supply hole 285 opens in the vicinity of the outer ring raceway surface 81 c that does not interfere with the cylindrical roller 83. An annular circumferential groove 286 is formed on the outer peripheral surface of the outer ring 281 at an axial position where the oil supply hole 285 opens. Thereby, the lubricating oil supplied from the oil supply passage 92 formed in the rear lid 34 is supplied via the circumferential groove 286 and the oil supply hole 285. In addition, the oil supply hole 285 may be used alone, or the oil supply from the nozzle of the rear bearing outer ring presser 43 may be used in combination. The circumferential groove 286 may be formed in a circular arc shape in cross section.

  An oil drain hole 81 b is formed on the opposite side of the oil supply hole 285 of the outer ring 281 in the axial direction across the cylindrical roller 83. An annular oil collecting groove 87b is formed on the inner circumferential surface of the outer ring 281 at the axial position where the oil drainage hole 81b is opened, and an annular circumferential groove is formed on the outer circumferential surface of the outer ring 281. 85 b is formed, and the circumferential groove 85 b communicates between the oil drain hole 81 b and the oil drain hole 34 b of the oil drain passage 102. As a result, the lubricating oil supplied from the oil supply hole 285 and lubricated inside the bearing passes through the oil collection groove 87b, the oil drain hole 81b, the circumferential groove 85b, and the oil discharge passage 102 by the suction force of the negative pressure generator 103. Forcibly discharged outside.

  The retainer 84 has substantially the same configuration as that of the first embodiment, and is formed so that the escape portion 84d avoids interference with the oil supply hole 285 and the oil collecting groove 87b. Therefore, the retainer 84 is located at a position where the annular portions 84a and 84b at both ends do not overlap with the oil supply hole 285 and the oil discharge hole 81b when viewed from the radial direction, that is, the shafts of the oil supply hole 285 and the oil collection groove 87b, respectively. Outside the direction, the outer ring is guided in sliding contact with the inner peripheral surface 81f of the outer ring 281. In FIG. 14, for the sake of simplification, the oil supply hole 285 and the oil discharge hole 81b are shown in the same cross section, but actually, they are arranged in different phases.

Therefore, in this embodiment, the annular portions 84a and 84b, which are guide surfaces of the cage 84, are not scraped by the opening edges of the oil supply holes 285 and the oil collecting grooves 87b, and wear of the cage 84 is prevented. .
Other configurations and operations are the same as those of the first and fifth embodiments.

  In addition, as in the modification shown in FIG. 14B, the relief portion 84d is formed on the inner portion of the outer peripheral surface of one annular portion 84a, the outer peripheral surface of the column portion 84c, and the outer peripheral surface of the other annular portion 84b. Of the one annular portion 84a, the retainer 84 is disposed at a position where it does not overlap with the oil supply hole 285 when viewed from the radial direction, in other words, at a portion positioned axially outside the oil supply hole 285. It may be guided to the inner peripheral surface 281f of 281. In this case as well, the retainer 84 is guided to the outer ring by the annular portion 84a located on the same side as the oil supply side, so that the oil supplied is reliably lubricated not only to the cylindrical roller 83 but also to the guide surface.

(Seventh embodiment)
Next, a spindle device bearing according to a seventh embodiment of the present invention will be described in detail with reference to FIG. In the present embodiment, the configuration of the cylindrical roller bearing which is the rear bearing is different from those of the first, fifth and sixth embodiments. Therefore, the same parts as those in the first, fifth, and sixth embodiments are denoted by the same reference numerals, and description thereof is omitted or simplified.

  As shown in FIG. 15A, in the cylindrical roller bearing 380 of the present embodiment, oil drain holes 381a and 381b that are formed to penetrate the outer ring 381 in the radial direction are formed on the outer side in the axial direction of the outer ring 381. ing. An annular oil collecting groove 387a, 387b is formed in the inner peripheral surface of the outer ring 381 at the axial position where the oil drain holes 381a, 381b are opened, and an annular oil collecting groove 387a, 387b is formed in the outer peripheral surface of the outer ring 381. Circumferential grooves 85a and 85b are formed.

  The cage 384 includes a pair of annular portions 384a and 384b and a plurality of column portions 384c, and a relief portion 384d is provided with the outer peripheral surface of the column portion 384c having a small diameter. The axial width is formed narrower than the axial distance between the oil drain holes 381a and 381b.

Accordingly, the retainer 384 is guided by the outer ring when the annular portions 384a and 384b are in sliding contact with the respective inner peripheral surfaces 381f between the outer ring raceway surface 81c and the oil drain holes 381a and 381b. As a result, the annular portions 384a and 384b are not scraped by the opening edges of the oil collecting grooves 387a and 387b, and wear of the cage 384 is prevented.
Other configurations and operations are the same as those of the first, fifth and sixth embodiments.

  As shown in the modification of FIG. 15B, when the oil drain hole 381a is formed only on one side in the axial direction, the oil drain hole 381a is the side that supplies lubricating oil to the cylindrical roller 83. It is formed on the opposite side (indicated by an arrow in the figure). Also in this case, oil collecting grooves 387a and circumferential grooves 85a are formed at positions where the oil drain holes 381a open to the inner peripheral surface and the outer peripheral surface.

  In addition, as shown in another modification of FIG. 16A, the cage 384 is one circle located on the opposite side to the side (indicated by an arrow in the drawing) for supplying lubricating oil to the cylindrical roller 83. The outer ring may be guided by the ring portion 384a. Further, as shown in still another modified example of FIG. 16B, the oil drain hole 381a, the oil collecting groove 387a, and the circumferential groove 85a supply lubricating oil to the cylindrical roller 83 (arrow in the figure). It may be formed only on the side opposite to that shown in FIG.

In addition, this invention is not limited to each embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
In this embodiment, the front bearings 60 and 70 are two rows of angular ball bearings, and the rear bearing 80 is a cylindrical roller bearing. However, the type and number of rows of each bearing can be arbitrarily set.
In this embodiment, the oil drain holes 71a and 71b of the angular ball bearing and the oil drain holes 81a and 81b of the cylindrical roller bearing are formed in a plurality in the circumferential direction, but at least one is formed in the circumferential direction. It only has to be done.

  Further, as in the machine tool spindle device 20a shown in FIG. 17, the oil drain holes of the bearings 60, 70, and 80 communicate with a single oil drain passage 110 formed in the housing H, and this oil drain passage. 110 may be connected to the negative pressure generator 103 via a pipe (not shown).

  As a result, the lubricating oil that has lubricated the bearings 60, 70, and 80 is forcibly sucked by the suction force of the negative pressure generating device 103, and then flows from the single drainage passage 110 to the outside via the drainage hole. Excessive lubricating oil and abnormal heat generation inside the bearing can be suppressed. In addition, the number of oil drain passages drilled in the housing H can be reduced, and the processing cost can be reduced. In FIG. 17, the nozzles 40a and 40b of the front bearings 60 and 70 having different phases and the nozzle 43a of the rear bearing 80 are shown in the same cross section.

  In the present embodiment, a plurality of oil supply passages 90, 91, 92 are provided for each of the bearings 60, 70, 80. However, the spindle device 20 is configured by using these oil supply passages 90, 91, 92 as a single oil supply passage. It may be possible to supply it by branching the inside thereof, and an optimum method can be selected as to whether a separate passage or a single common passage is used for each of the plurality of bearings depending on the lubrication method and lubrication conditions.

1 is a schematic view of a portal machining center to which a spindle device including a bearing of the present invention is applied. In the spindle device to which the bearing of the first embodiment is applied, it is a cross-sectional view showing an oil supply passage and an oil discharge passage of one front bearing. FIG. 4 is a cross-sectional view showing an oil supply passage and an oil discharge passage of the other front bearing in the spindle device. In a main shaft device, it is a sectional view showing an oil supply passage and an oil discharge passage of a rear bearing. It is an expanded sectional view of the front side bearing of a main shaft device. It is an expanded sectional view which shows the modification of the front side bearing of a main shaft apparatus. It is an expanded sectional view of the rear bearing of a main shaft device. (A)-(h) is a figure which shows each pattern of the oil supply direction and oil supply position of a rear side bearing. It is an expanded sectional view showing the modification of the rear bearing of this embodiment. It is an expanded sectional view of the front side bearing which concerns on the spindle apparatus bearing of 2nd Embodiment. (A) is an expanded sectional view of the front bearing which concerns on the spindle apparatus bearing of 3rd Embodiment, (b) is an expanded sectional view which shows the modification. It is an expanded sectional view of the front side bearing which concerns on the spindle apparatus bearing of 4th Embodiment. (A) is an expanded sectional view of the rear bearing which concerns on the spindle apparatus bearing of 5th Embodiment, (b) is an expanded sectional view which shows the modification. (A) is an expanded sectional view of the rear bearing which concerns on the spindle apparatus bearing of 6th Embodiment, (b) is an expanded sectional view which shows the modification. (A) is an expanded sectional view of the rear bearing which concerns on the spindle apparatus bearing of 7th Embodiment, (b) is an expanded sectional view which shows the modification. (A) is an expanded sectional view which shows the other modification of 8th Embodiment, (b) is an expanded sectional view which shows another modification. It is sectional drawing which shows the modification of a main axis | shaft apparatus. It is sectional drawing in the conventional main axis | shaft apparatus.

Explanation of symbols

1 Portal machining center (multi-task machine tool)
20 Spindle device 22 Rotating shaft 60, 70, 170, 270, 370 Front bearing (angular ball bearing)
61, 71, 81, 171, 271, 371, 281, 381 Outer rings 62, 72, 82 Inner rings 71a, 71b, 81a, 81b, 171a, 171b, 271a, 271b, 381a, 381b Oil drain holes 73 Balls 64, 74, 84,174,184,274,374,384 Cage 80, 180, 280, 380 Rear bearing (cylindrical roller bearing)
100, 101, 102 Oil drainage passage 103 Negative pressure generator H Housing L Virtual line O Center of ball

Claims (3)

An inner ring having an inner ring raceway surface on the outer peripheral surface;
An outer ring having an outer ring raceway surface on the inner circumferential surface;
A plurality of rolling elements disposed between the inner ring raceway surface and the outer ring raceway surface;
A cage that holds the plurality of rolling elements in a freely rollable manner;
A bearing for a spindle device that rotatably supports a rotating shaft with respect to a housing and is lubricated by oil lubrication,
An oil drainage hole is formed in the outer ring in the radial direction, and a negative pressure is applied to the oil drainage hole by a suction force from the outside of the bearing.
A bearing for a main shaft device, wherein the retainer is guided by an outer ring at an outer peripheral surface at a position where it does not overlap with an inner peripheral side opening of the oil drainage hole when viewed in the radial direction. The spindle device bearing is an angular ball bearing in which a ball has a contact angle and is disposed between the outer ring raceway surface and the inner ring raceway surface,
The oil drain hole formed on the counter-bore side of the outer ring is spaced outward in the axial direction from the intersection of an imaginary line formed by the contact angle and the outer peripheral surface of the outer ring that passes through the center of the ball. The spindle device bearing according to claim 1, wherein the bearing is formed at a position. The main shaft device bearing is a cylindrical roller bearing in which a cylindrical roller is disposed between the outer ring raceway surface and the inner ring raceway surface, and the inner ring has a pair of flange portions on both sides in the axial direction of the inner ring raceway surface,
The bearing for a spindle apparatus according to claim 1, wherein an oil supply hole for supplying the lubricating oil is further formed in the outer ring in a radial direction.

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