JP2008240946A - Lubricating device for rolling bearing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating device for a rolling bearing capable of performing lubricating oil supply in combination with cooling of a bearing, capable of reducing stirring resistance of lubricating oil by limiting the quantity of lubricating oil entering the bearing, and not requiring difficult work on an inner ring of the rolling bearing. <P>SOLUTION: This device is provided with an inner ring spacer 21A touching an end surface F1 of an inner ring 2 of the rolling bearing. A circumference groove 6 continuing on a whole circumference of the inner ring spacer 21A is provided over an outer diameter surface from an end surface at an opposite side to the inner ring 2 of the inner ring spacer 21A. A nozzle 8 discharging lubricating oil which is also used as a bearing cooling medium in the circumference groove 6 is provided on a lubricating oil introduction member 7 adjoining an outer ring 3 of the roller bearing. Inclined surface parts 21Aa, 2b connected to an outer diameter surface of the inner ring 2 and an outer diameter surface of the inner ring spacer 21A and leading lubricating oil in the circumference groove 6 to a raceway surface of the inner ring 2 by centrifugal force due to rotation of the inner ring 2 and the inner ring spacer 21A and surface tension are provided. A covering part 7c covering a whole circumference of the inclined surface part 21Aa of the inner ring spacer 21A and forming a gap δ in which lubricating oil flows from the inclined surface part 21Aa is provided on the lubricating oil introduction member 7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rolling bearing lubrication device used for supporting a high-speed spindle such as a spindle for a machine tool.

  Machine tool spindles are becoming increasingly faster in order to increase machining efficiency. As the spindle speed increases, torque and heat generation increase in the spindle bearing. In order to cope with this, jet lubrication that simultaneously lubricates and cools the bearing by injecting a large amount of oil into the bearing is used. However, this jet lubrication generally has a drawback that the power loss is increased due to the agitation resistance caused by the oil contained in the bearing.

Therefore, a new jet lubrication structure has been proposed in which the amount of lubricating oil entering the bearing is limited to reduce the agitation resistance due to oil (for example, Patent Document 1). The new jet lubrication structure disclosed in Patent Document 1 receives the lubricating oil discharged from the lubricating oil introducing member formed of an outer ring spacer or the like by a circumferential groove provided on the end face of the inner ring to cool the inner ring heat generation. . Most of the cooled lubricating oil is discharged out of the bearing, but a part of it is used for bearing lubrication, and the gap between the lubricating oil introduction member and the outer ring slope of the inner ring is used for the inner ring raceway surface. Inflow. That is, only a small amount of lubricating oil required for bearing lubrication enters the bearing. For this reason, stirring resistance becomes small and the power loss of a bearing becomes small.
Further, in a type of lubrication device that supplies lubricating oil together with air to a bearing, Patent Documents 2 and 3 are cited as techniques related to this case.
JP 2006-118525 A Japanese Patent Laid-Open No. 2001-12481 JP 2002-130303 A

In the new jet lubrication structure disclosed in Patent Document 1 and the like, it is necessary to provide a circumferential groove on the end face of the inner ring of the rolling bearing for receiving the lubricating oil discharged from the lubricating oil introduction member. Thus, a standard rolling bearing could not be used.
In addition, since the inner and outer rings of rolling bearings require high-precision machining and high-temperature heat treatment, providing a circumferential groove in the inner ring ensures that each part of the inner ring is machined accurately and is suitable for the raceway surface of the inner ring. It becomes difficult to perform an appropriate heat treatment. For example, the angular ball bearing has an advantage that it is suitable for high-precision machining because of its simple structure. However, if a circumferential groove is provided in the inner ring, the advantage is lost.

  The object of the present invention is to supply lubricating oil that also serves as cooling for the bearing, to limit the amount of lubricating oil entering the bearing, to reduce the stirring resistance of the lubricating oil, and to perform difficult machining on the inner ring of the rolling bearing It is an object of the present invention to provide a rolling bearing lubrication device that is unnecessary.

  A lubricating device for a rolling bearing according to the present invention includes an inner ring spacer that is in contact with an end surface of an inner ring of the rolling bearing, and the entire circumference of the inner ring spacer extends from an end surface opposite to the inner ring to an outer diameter surface of the inner ring spacer. And a nozzle for discharging lubricating oil that also serves as a bearing cooling medium is provided in the lubricating oil introducing member adjacent to the outer ring of the rolling bearing, and the outer diameter surface of the inner ring and Continuing from each other on the outer diameter surface of the inner ring spacer, a slope portion is provided for guiding the lubricating oil in the circumferential groove to the raceway surface of the inner ring by centrifugal force and surface tension due to rotation of the inner ring and the inner ring spacer, The lubricating oil introducing member is provided with a covering portion that covers the entire circumference of the slope portion of the inner ring spacer and forms a gap through which the lubricating oil flows.

According to this configuration, the lubricating oil discharged from the nozzle is received by the circumferential groove provided on the end face of the inner ring spacer, and cools the inner ring spacer and the inner ring in contact therewith. Most of the lubricating oil received in the circumferential groove is released from the circumferential groove to the outer diameter side by centrifugal force. A part of the lubricating oil in the circumferential groove is caused by centrifugal force and surface tension due to rotation of the inner ring and the inner ring spacer, along the outer diameter surface of the inner ring and the inclined surface portion provided on the outer diameter surface of the inner ring spacer. Guided to the raceway of the inner ring and used for lubrication. Lubricating oil supplied to the raceway surface of the inner ring flows from the circumferential groove into the bearing through a gap formed between the inclined surface portion of the inner ring spacer and the covered portion of the lubricating oil introduction member. By appropriately setting the gap interval, the amount of lubricating oil flowing into the bearing can be limited to the amount necessary for lubricating the bearing. Therefore, the stirring resistance due to oil in the bearing can be reduced, and the power loss of the bearing can be reduced.
Since the circumferential groove is provided in the inner ring spacer, it is not necessary to process the circumferential groove in the inner ring of the rolling bearing, and each part of the inner ring can be processed with high accuracy. Since there is no circumferential groove in the inner ring, a rolling bearing having a standard shape can be used. Since the inner ring spacer does not require heat treatment, it is easy to provide a circumferential groove in the inner ring spacer.
Further, since the gap is formed between the inner ring spacer and the lubricating oil introduction member, which are members different from the rolling bearing, there is no need to adjust the rolling bearing for gap management, Clearance management is easy.

In the present invention, the axial position of the inner ring end face on the side where the inner ring spacer is in contact with the axial position of the outer ring end face on the side adjacent to the lubricating oil introduction member may be the same position. Alternatively, the axial position of the inner ring end face on the side where the inner ring spacer is in contact may be a position where the lubricating oil introduction member is retracted toward the raceway side of the inner ring than the axial position of the outer ring end face on the adjacent side.
In either case, the above action can be obtained. In particular, when the axial position of the inner ring end face and the axial position of the outer ring end face are the same, there is an advantage that a rolling bearing having a standard size can be used.

In the present invention, when the rolling bearing is an angular ball bearing, the inclined surface portion of the inner ring is preferably provided on the outer diameter surface portion opposite to the direction in which the contact angle is generated with respect to the raceway surface of the inner ring. .
The portion of the inner ring outer diameter surface opposite to the direction in which the contact angle is generated with respect to the raceway surface of the inner ring is not subjected to the axial load from the rolling elements. This is because there are few problems in strength.

  The lubricating device for a rolling bearing according to the present invention is provided with an inner ring spacer that is in contact with an end face of the inner ring of the rolling bearing, and extends from the end face on the opposite side of the inner ring spacer to the inner ring over the outer diameter surface to the entire circumference of the inner ring spacer. A continuous circumferential groove is provided, and a nozzle that discharges lubricating oil that also serves as a bearing cooling medium is provided in the circumferential groove in the lubricating oil introduction member adjacent to the outer ring of the rolling bearing, and the outer diameter surface of the inner ring and the The outer ring surface of the inner ring spacer is continuously provided with an inclined surface portion that guides the lubricating oil in the circumferential groove to the raceway surface of the inner ring by centrifugal force and surface tension due to rotation of the inner ring and the inner ring spacer, Since the oil introduction member is provided with a cover portion that covers the entire circumference of the slope portion of the inner ring spacer and forms a gap through which the lubricant oil flows, the lubricating oil supply that also serves as cooling of the bearing can be performed. Limit the amount of lubricating oil entering the bearing and reduce the stirring resistance of the lubricating oil It can be. Further, since there is no need to perform complicated machining on the inner ring of the rolling bearing, the inner ring can be machined with high accuracy, and a rolling bearing having a standard shape can be used.

  A first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a sectional view of a rolling bearing lubrication device of this embodiment. This rolling bearing lubrication device jets a large amount of lubricating oil from the lubricating oil introducing member 7 toward the rolling bearing 1 to simultaneously lubricate and cool the bearing.

  The rolling bearing 1 is formed of an angular ball bearing, and as shown in an enlarged view in FIG. 2, a plurality of rolling elements 4 interposed between the inner ring 2, the outer ring 3, and the raceway surfaces 2 a and 3 a of these inner and outer rings 2 and 3. And have. The rolling element 4 is formed of a ball, and is held by a ring-shaped cage 5 at a predetermined interval in the circumferential direction. A slope portion 2b having a larger diameter as it approaches the raceway surface 2a is provided on a portion of the outer diameter surface of the inner race 2 opposite to the direction in which the contact angle with respect to the raceway surface of the inner race is generated. In this embodiment, the axial position of the inner ring end face F1 on the side where the first inner ring spacer 21A is in contact with the axial position of the outer ring end face F2 on the side where the lubricating oil introduction member 7 is adjacent are the same position. For this reason, an angular ball bearing with a standard size can be used as the rolling bearing 1.

  This rolling bearing 1 is used as a spindle bearing of a machine tool. The inner ring 2 is fitted to the outer diameter surface of the main shaft 25 and is positioned by inner ring spacers 21A and 21B. The outer ring 3 is fixed in a bearing box (not shown) and is positioned by the lubricating oil introducing member 7 which is an outer ring positioning spacer.

  The inner ring spacer is divided into a first inner ring spacer 21A that contacts the end face F1 of the inner ring 2, and a second inner ring spacer 21B that contacts the end face of the first inner ring spacer 21A opposite to the inner ring 2. . Then, a circumferential groove 6 is provided extending from the end surface of the first inner ring spacer 21A on the opposite side to the inner ring 2 to the outer diameter surface. The outer diameter surface of the first inner ring spacer 21 </ b> A is formed as a slope portion 21 </ b> Aa following the slope portion 2 b of the inner ring 2. The diameter of the inner ring side end of the second inner ring spacer 21B is larger than the diameter of the end opposite to the inner ring 2 of the first inner ring spacer 21A, and the circumferential groove is formed by the inner ring side end surface of the second inner ring spacer 21B. The surface of the inner ring 2 opposite to the inner ring 2 is closed, and the circumferential groove 6 is open only on the outer diameter side.

  The lubricating oil introduction member 7 extends from the outer diameter surface of the lubricating oil introduction member 7 toward the inner diameter side and communicates with the nozzle 8 and discharges the lubricating oil into the circumferential groove 6 of the first inner ring spacer 21A. And an oil supply passage 9. In this embodiment, the nozzle 8 is formed at an inclination angle toward the center position of the bottom surface of the circumferential groove 6. The lubricant introduction member 7 is combined with a release lubricant regulation member 15.

  As shown in FIG. 3, the lubricating oil introduction member 7 is provided with nozzle forming protrusions 7b protruding toward the inner diameter side at a plurality of equally spaced positions (for example, three positions) in the circumferential direction of the annular body 7a. The nozzle 8 is provided on each nozzle forming protrusion 7b. The oil supply passage 9 extends from the bottom surface of the oil supply passage C-shaped groove portion 9a provided on the outer diameter surface of the annular main body 7a to the inner diameter side at the circumferential position of each nozzle forming protrusion 7b. It consists of an oil supply passage individual hole 9b. The nozzle 8 communicates with the tip of the oil supply passage individual hole 9b.

  An annular covering portion 7 c is provided at the end of the lubricating oil introducing member 7 on the rolling bearing 1 side. The covering portion 7c covers the entire slope of the slope portion 21Aa of the first inner ring spacer 21A, and forms a clearance δ for inflow of lubricating oil between the slope portion 21Aa. The inner diameter surface of the covering portion 7c is parallel to the slope portion 21Aa of the first inner ring spacer 21A, and the gap dimension of the gap δ is constant over the entire area.

  In one place of the end face of the lubricating oil introducing member 7 on the side where the discharged lubricating oil regulating member 15 is combined, the lubricating oil discharged from the nozzle 8 into the circumferential groove 6 does not enter the bearing space. A bearing outer oil discharge port 10 for discharging to the outside is provided. In addition, on the end surface of the lubricating oil introducing member 7 opposite to the side where the outer bearing oil draining port 10 is provided, the lubricating oil supplied to the inside of the rolling bearing 1 is discharged to the outside. A groove 11 and a bearing oil drain port 12 are provided. The in-bearing oil drain groove 11 is an annular groove, and the in-bearing oil drain port 12 is opened at one location of the in-bearing oil drain groove 11. The bearing outer oil outlet 10 and the bearing inner oil outlet 12 are provided at the same position in the circumferential direction. The bearing outer oil outlet 10 and the bearing inner oil outlet 12 are notched portions provided at the end of the annular main body 7a of the lubricating oil introducing member 7, but in the middle of the annular main body 7a in the width direction. It is good also as a through-hole located.

  The discharged lubricating oil regulating member 15 is a member that regulates the scattering of the lubricating oil discharged from the nozzle 8 of the lubricating oil introducing member 7 and released to the outer diameter side. The discharged lubricating oil regulating member 15 is a ring member having a groove shape in cross section opened to the rolling bearing 1 as a whole, but a part of the outer diameter portion is notched at the circumferential position of the bearing outer oil discharge port 10. Thus, the oil passage port 15a is connected, and the space on the circumferential groove 6 side of the lubricating oil introduction member 7 and the bearing outer oil discharge port 10 communicate with each other through the oil passage port 15a (FIG. 1). .

  According to the rolling bearing lubrication device of this configuration, the lubricating oil also serving as a cooling medium introduced from the outer diameter side of the lubricating oil introducing member 7 through the oil supply passage 9 is passed from the nozzle 8 to the circumferential groove of the first inner ring spacer 21A. The first inner ring spacer 21A and the inner ring 2 in contact with the first inner ring spacer 21 are cooled by this lubricating oil. The lubricating oil injected from the nozzle 8 is received by the bottom surface of the circumferential groove 6 and temporarily accumulates in the circumferential groove 6, so that the first inner ring spacer 21 </ b> A and the inner ring 2 can be effectively cooled.

  The lubricating oil received by the circumferential groove 6 cools the first inner ring spacer 21A and the inner ring 2 from the bottom surface of the circumferential groove 6 and then is discharged from the circumferential groove 6 to the outer diameter side by centrifugal force. Part of the lubricating oil released to the outer diameter side is centrifugal force and surface due to the rotation of the inner ring 2 along the first inner ring spacer 21A and the inclined surface portions 21Aa, 2b provided on the outer diameter surface of the inner ring 2. It flows to the raceway surface 2a side of the inner ring 2 due to the tension. Thereby, the rolling bearing 1 is lubricated. At that time, since the lubricating oil flows into the bearing through the gap δ between the inclined surface portion 21Aa of the first inner ring spacer 21A and the inner diameter surface 7ca of the lubricating oil introducing member covering portion 7c, the gap δ is spaced. By appropriately setting, the amount of lubricating oil entering the bearing can be limited to the amount necessary for lubricating the bearing. Thereby, the stirring resistance by the oil in a bearing can be made small, and the power loss of a bearing can be restrained small. Lubricating oil that has not been supplied into the bearing from the gap δ is discharged to the outside from the bearing outer oil outlet 10 of the lubricating oil introduction member 7 as discharged oil.

  In the rolling bearing lubrication device having this configuration, since the circumferential groove 6 is provided in the first inner ring spacer 21A, it is not necessary to process the circumferential groove in the inner ring 2, and each part of the inner ring 2 can be machined with high accuracy. it can. Further, since the inner ring 2 has no circumferential groove, a rolling bearing 1 having a standard shape can be used. Since the inner ring spacers 21A and 21B do not require heat treatment, it is easy to provide the circumferential groove 6 in the first inner ring spacer 21A.

  FIG. 4 shows a second embodiment of the present invention. The second embodiment differs from the first embodiment shown in FIGS. 1 to 3 in the following points. That is, in the first embodiment, the axial position of the inner ring end face F1 on the side where the first inner ring spacer 21A is in contact and the axial position of the outer ring end face F2 on the side where the lubricating oil introduction member 7 is adjacent are the same. In contrast to this, in the second embodiment, the axial position of the inner ring end face F1 on the side where the first inner ring spacer 21A contacts is the axial position of the outer ring end face F2 on the side where the lubricant introduction member 7 is adjacent. The position of the inner ring 2 is retracted toward the raceway surface 2a. Accordingly, the shape of each part of the rolling bearing 1, the lubricating oil introducing member 7, and the inner ring spacers 21A and 21B is different from that of the first embodiment, but the basic configuration is the first and second implementations. The form is the same. Therefore, the operation and effect of the second embodiment are the same as those of the first embodiment.

  The lubrication device for a rolling bearing according to the present invention enables a high-precision machining of the inner ring by providing a circumferential groove in an inner ring spacer provided separately from the inner ring of the rolling bearing, and uses a rolling bearing having a standard shape. However, depending on various situations and conditions, for example, as shown in FIG. 5, the inner ring 2 of the rolling bearing 1 and the first inner ring spacer 21A in the first embodiment are integrated. The inner ring 2 ′ with the circumferential groove 6 can be used.

FIG. 6 shows an example of a high-speed spindle device equipped with the rolling bearing lubrication device of the first embodiment shown in FIGS. The spindle device 24 is applied to a machine tool, and a tool or workpiece chuck is attached to an end of a main shaft 25. The main shaft 25 is supported by a pair of rolling bearings 1 at the front (processing side) end and the rear end in the axial direction. The spindle housing includes an outer housing 43, an inner housing 44, and a front bearing box 26A and a rear bearing box 26B that are fitted inside the inner housing 44. A motor 45 is accommodated at an axial position between the front bearing box 26A and the rear bearing box 26B.
The inner ring 2 of each rolling bearing 1 is fitted to the outer diameter surface of the main shaft 25, and the outer ring 3 is fitted to the inner diameter surface of the front bearing box 26A or the rear bearing box 26B. A pair of rolling bearings 1 which are angular ball bearings are provided in a combination on the back surface, and each inner ring 2 is positioned with respect to each other by a first inner ring spacer 21A and a second inner ring spacer 21B. They are positioned with respect to each other by the lubricant introduction member 7. The inner ring holder 28 is pressed against the inner ring 2 of the rolling bearing 1 on the shaft end side via the inner ring positioning member 27, and the outer ring holder 30 is pressed against the outer ring 3 via the outer ring positioning member 29. Is fixed to the bearing housings 26A and 26B.

  The bearing housings 26 </ b> A and 26 </ b> B and the outer ring retainer 30 are provided with cooling oil introduction holes 33 for introducing lubricating oil cooled from a cooling oil supply device 32 that is a supply source when the rolling bearing 1 is jet lubricated. The cooling oil introduction hole 33 communicates with the oil supply passage 9 of the lubricating oil introduction member 7. The oil supply path 38 from the cooling oil supply device 32 is connected to the cooling oil introduction hole 33 through the oil filter 40 and the pressure adjustment valve 41. The bearing housings 26 </ b> A and 26 </ b> B and the outer ring retainer 30 are provided with oil drain holes 35 that return the oil drained after jet lubrication to the cooling oil supply device 32. The oil drain hole 35 communicates with the bearing outer oil outlet 10 and the bearing inner oil outlet 12 of the lubricating oil introduction member 7. Waste oil that has been used for cooling and lubrication of the bearing and that has flowed out of the oil drain ports 10 and 12 is recovered from the oil drain hole 35 through the oil drain pump 37 to the cooling oil supply device 32.

  In addition, although this spindle apparatus 24 demonstrated the case where the lubrication apparatus of the rolling bearing which concerns on 1st Embodiment was applied, you may use the lubrication apparatus of the rolling bearing which concerns on any other embodiment.

It is sectional drawing of the lubricating device of the rolling bearing which concerns on 1st Embodiment of this invention. It is a partial expanded sectional view of the lubricating device. (A) is the front view of the lubricating oil introduction member in the lubricating device of the rolling bearing of the embodiment, (B) is the sectional view. It is a partial expanded sectional view of the lubricating device of the rolling ball bearing which concerns on 2nd Embodiment of this invention. It is a partial expanded sectional view of the lubricating device of the rolling ball bearing as a proposal example. It is a block diagram of the spindle apparatus provided with the lubricating device of the rolling bearing of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rolling bearing 2 ... Inner ring 2a ... Raceway surface 2b ... Slope part 3 ... Outer ring 4 ... Rolling body 5 ... Cage 6 ... Circumferential groove 7 ... Lubricating oil introduction member 7c ... Cover part 8 ... Nozzle 21A ... Between 1st inner rings Seat 21Aa ... Slope 21B ... Second inner ring spacer F1 ... Inner ring end face F2 ... Outer ring end face δ ... Gap

Claims (4)

  An inner ring spacer is provided in contact with the end face of the inner ring of the rolling bearing, and a circumferential groove is provided from the end face opposite to the inner ring to the outer diameter surface of the inner ring spacer, following the entire circumference of the inner ring spacer. A nozzle for discharging lubricating oil that also serves as a bearing cooling medium is provided in the groove on a lubricating oil introduction member adjacent to the outer ring of the rolling bearing, and is continuous with the outer diameter surface of the inner ring and the outer diameter surface of the inner ring spacer. And a slope portion for guiding the lubricating oil in the circumferential groove to the raceway surface of the inner ring by centrifugal force and surface tension due to rotation of the inner ring and the inner ring spacer, and the lubricating oil introduction member is provided with the inner ring spacer. A rolling bearing lubrication device comprising a covering portion that covers the entire circumference of a slope portion and that forms a gap through which lubricating oil flows between the slope portion and the slope portion.   2. The lubricating device for a rolling bearing according to claim 1, wherein the axial position of the inner ring end face on the side contacting the inner ring spacer and the axial position of the outer ring end face on the side adjacent to the lubricating oil introduction member are the same position. .   2. The rolling according to claim 1, wherein the axial position of the inner ring end face on the side in contact with the inner ring spacer is a position where the lubricating oil introduction member is retracted to the raceway side of the inner ring with respect to the axial position of the outer ring end face on the adjacent side. Bearing lubrication equipment. 4. The rolling bearing according to claim 1, wherein the rolling bearing is an angular ball bearing, and the inclined surface portion of the inner ring is disposed on an outer side opposite to a direction in which a contact angle is generated with respect to a raceway surface of the inner ring. A rolling bearing lubrication device provided on the radial surface portion.

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