JP5908732B2 - Rolling bearing device - Google Patents

Description

  The present invention relates to a rolling bearing device such as a machine tool spindle, and more particularly to a rolling bearing device capable of performing stable lubrication for a long time by self-power generation.

  2. Description of the Related Art A rolling bearing device including a self-power generation type oil supply unit has been known (see Patent Document 1). In this bearing device, an oil supply unit is mounted on the inner surface of the seal ring. The oil supply unit includes a tank in which lubricating oil is stored, a micropump (hereinafter simply referred to as a pump) that discharges the lubricating oil in the tank to a bearing, and an internal power source (generator or battery) that drives the pump. The Lubricating oil is discharged from the discharge port of the pump toward the inside of the bearing.

  Further, a rolling bearing device including a rolling bearing, an inner and outer ring spacer fitted on the shaft adjacent to the rolling bearing, and a grease reservoir member incorporated between the inner and outer ring spacers has been conventionally known. (Patent Document 2). The grease reservoir member has a gap forming portion extending to the bearing side, and a discharge gap is formed over the entire circumference between the gap forming portion and the step surface of the bearing outer ring.

  Lubricating oil (base oil) is separated from the grease sealed in the grease reservoir member as the temperature of the bearing rises, and the separated lubricating oil is supplied into the bearing by capillary action in the discharge gap. In this case, the lubricating oil can be supplied to the bearing side without using a pump.

JP 2004-108388 A JP 2010-19268 A

  However, in the case of Patent Document 1, it is necessary to incorporate an oil supply set inside the rolling bearing itself, and there is a problem that the structure of the bearing becomes complicated, and the assembling work is complicated and expensive. In the case of Patent Document 2, these problems have been solved for the time being, but since one set of oil supply unit is provided for one rolling bearing, there is a problem that the use efficiency of the oil supply unit is low.

  In view of this, the present invention aims to improve the efficiency of use of the oil supply unit and reduce the cost of the rolling bearing device by supplying oil to the two rolling bearings simultaneously from a set of oil supply units incorporated in the intermediate spacer. Let it be an issue.

  In order to solve the above-described problems, a rolling bearing device according to the present invention includes a rolling bearing, a rotating ring spacer and a fixed ring between the rotating ring spacer and the fixed ring, which are in contact with axial end surfaces of the rotating ring and the fixed ring, respectively. And an oil supply unit attached to the fixed ring spacer. The oil supply unit drives a casing, a lubricating oil tank provided inside the casing, a pump, a power generation unit, and the pump. The pump suction tube communicates with the lubricating oil tank, the discharge tube communicates with a nozzle provided toward the rolling bearing, and the rolling bearing is spaced apart in the axial direction. A pair of disposed, the rotating ring spacer and the fixed ring spacer are interposed as intermediate spacers between these rolling bearings, the nozzles are respectively provided on both side walls of the casing, Serial discharge tube is branched at the branch portion, each branch discharge tube which branches is obtained by a structure which is communicated with the nozzles respectively.

  By driving the pump, the lubricating oil in the lubricating oil tank is supplied from each nozzle to the rolling bearings on both sides via the suction tube, the discharge tube, the branch portion, and both branch discharge tubes.

  Each of the nozzles is provided to protrude on both side walls of the casing in an annular shape, and each of the nozzles is fitted to a stepped portion provided on a shoulder portion of a fixed ring of each rolling bearing. A configuration in which the branch passages are respectively connected to the provided nozzle holes can be employed.

  Further, the branch portion is constituted by a T-shaped joint, the inlet side of the T-shaped joint is connected to the discharge tube, and two branch passages that are the outlet side of the T-shaped joint are connected to the nozzle holes, respectively. Can be configured.

  Moreover, the branch discharge tube connected to the branch side of the T-shaped joint can pass through both side walls of the casing, and the nozzles can be connected to the branch discharge tubes, respectively.

  The axial length of either one of the spacers, wherein the rotating ring spacer and the fixed ring spacer are made of a metal material and the distance between the contact points of the rolling elements of the pair of angular ball bearings is smaller. It is possible to adopt a configuration in which the length is set larger than the axial length of the other spacer. With this configuration, it is possible to apply a predetermined bearing preload to the rolling bearings on both sides.

  The drive unit includes a control circuit unit and a capacitor that charges a current supplied from the power generation unit, and discharges the capacitor when the control circuit unit determines that a predetermined condition is satisfied. The pump can be driven by the discharge current.

(1) Since the oil supply unit is provided in the intermediate spacer sandwiched between the rolling bearings, a rolling bearing having a normal configuration can be used.

(2) Since the oil supply unit is provided in the intermediate spacer, two rolling bearings in contact with the intermediate spacer can be lubricated simultaneously. As a result, the use efficiency of the oil supply unit is increased, so that the number of the oil supply units can be reduced, and the cost of the apparatus can be reduced.

(3) Since the oil supply unit is attached only to the intermediate spacer, the structure is simple and it is possible to make it compact. Further, when the oil supply unit fails or when the lubricating oil is lost, it is only necessary to replace the intermediate spacer or the oil supply unit.

(4) Since the pump is driven by self-power generation, the intermediate spacer is compact and can be easily assembled between a pair of rolling bearings.

(5) By utilizing the heat generated by the rolling bearing as a self-power generation method, the oil supply unit can be incorporated into the fixed side of the intermediate spacer, and the assembly is facilitated.

It is sectional drawing of the rolling bearing apparatus of Embodiment 1 which concerns on this invention. FIG. 2 is a reduced cross-sectional view taken along line X1-X1 of FIG. It is an expanded sectional view of the X2-X2 line of FIG. It is a block diagram which shows the drive relationship of a pump. It is sectional drawing of the X3-X3 line | wire of FIG. It is sectional drawing of the rolling bearing apparatus of Embodiment 2 which concerns on this invention. It is sectional drawing of the rolling bearing apparatus of Embodiment 3 which concerns on this invention. It is sectional drawing of the X4-X4 line | wire of FIG.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
[Embodiment 1]

  The rolling bearing device 10 according to the first embodiment shown in FIGS. 1 to 5 includes a pair of left and right rolling bearings 11 and 11a arranged at a predetermined interval in the axial direction, and between these rolling bearings 11 and 11a. The intermediate spacer 12 is interposed, and an oil supply unit 13 is assembled to the intermediate spacer 12. It is used between a rotary shaft 14 such as a machine tool spindle and housings 15 and 15a.

  The rolling bearings 11 and 11a (in the illustrated example, angular contact ball bearings) include an inner ring 17 that is a rotating ring, an outer ring 18 that is a fixed ring, a required number of rolling elements 19 interposed between these races, and rolling elements thereof. It is comprised by the holder | retainer 20 which hold | maintains the moving body 19 at a fixed space | interval. The bearings 11 and 11a face each other with the front side facing inward, and a seal member 21 is mounted between the inner and outer rings 17 and 18 on the rear side.

  The intermediate spacer 12 includes an inner ring spacer 22 that is a rotating ring spacer and an outer ring spacer 23 that is a fixed ring spacer, and is interposed between the end faces of the inner ring 17 and the outer ring 18 of the rolling bearings 11 and 11a on both sides. The The inner ring spacer 22 is fitted and fixed to the outer diameter surface of the rotating shaft 14, and the outer ring spacer 23 is fixed to the inner diameter surface of the housing 15.

  The outer ring 18 of one rolling bearing 11 is positioned in the axial direction by a presser lid 61 fixed to the housing 15, and the outer ring 18 of the other rolling bearing 11 a is positioned in the axial direction by a step portion 15 a of the housing 15. The inner ring 17 of the rolling bearing 11 is positioned in the axial direction by the flange portion 14 a of the rotating shaft 14, and the inner ring 17 of the other rolling bearing 11 a is positioned in the axial direction by closing the nut 30 via the spacer 62. The

  The oblique line a representing the contact angle connecting the contact point A1 between the inner ring 17 and the rolling element 19 of the one rolling bearing 11 and the contact point B1 between the outer ring 18 and the rolling element 19 is inclined outward in the axial direction with respect to the center of the bearing device. doing. The oblique line a representing the contact angle connecting the contact point A2 between the inner ring 17 and the rolling element 19 of the other rolling bearing 11a and the contact point B2 between the outer ring 18 and the rolling element 19 is also inclined outward in the axial direction with respect to the center of the bearing device. ing.

  When the distance between both the rolling bearings 11 and 11a is constant, the relationship between the axial length L22 of the inner ring spacer 22 and the axial length L23 of the outer ring spacer 23 should be set as L22> L23. Thus, a predetermined bearing preload in the direction of the contact points B1 and B2 can be applied from the contact points A1 and A2 side.

  Generally, the axial length of the intermediate spacer (for example, the inner ring spacer 22) belonging to the smaller distance between the contact points (for example, the distance between the contact points A1 and A2) is determined by the distance between the contact points ( For example, the predetermined bearing preload can be applied by setting it to be larger than the axial length of the intermediate spacer (for example, the outer ring spacer 23) belonging to the larger contact point B1, B2.

  The oil supply unit 13 includes an annular resin casing 24 fixed to the inner diameter surface of the outer ring spacer 23. The casing 24 is bonded and fixed to the inner surface of the outer ring spacer 23 by an adhesive stored in a shallow circumferential groove 25 provided on the inner surface of the outer ring spacer 23.

  The casing 24 is formed by an inner peripheral wall 26, an outer peripheral wall 27, and both side walls 28, 28. An annular nozzle 31 projecting outward in the axial direction is provided at both corner portions formed by the outer peripheral wall 27 and both side walls 28 over the entire circumference. Each nozzle 31 is incorporated in a step portion 32 provided on the shoulder portion of the inner diameter surface of the outer ring 18.

  As shown in FIG. 2, radial partition walls 33, 34 are provided in the casing 24 at two locations in the circumferential direction, extending across the inner peripheral wall 26 and the outer peripheral wall 27 of the casing 24. The casing 24 is partitioned by the partition walls 33 and 34 into a lubricating oil tank 35 occupying a semicircular arc portion and the remaining arc portion.

  Each of the nozzles 31 has an inclined surface 41 facing the rolling element 19 on its inner diameter surface (see FIG. 1). An axial nozzle hole 43 is provided at a position facing the inclined surface 41 and the corners of the outer peripheral wall 27 and the side walls 28 near the partition wall 34 in the axial direction.

  Inside the casing 24 partitioned from the lubricating oil tank 35, as shown in FIG. 2, a power generation unit 45, a drive unit 46, and a pump 47 for self-power generation are arranged in order from a portion close to one partition wall 33. Is done.

  As shown in FIG. 3, the power generation unit 45 is obtained by sandwiching a thermoelectric element 48 such as a Seebeck element with heat sinks 49 a and 49 b formed of a metal (for example, copper or copper alloy) having good thermal conductivity. Both heat sinks 49a and 49b are fastened by screws 50 (see FIG. 2), and the thermoelectric element 48 is firmly held. As shown in FIG. 2, one heat sink 49 a is exposed to the inner diameter surface from the hole in the inner peripheral wall 26 of the casing 24, and faces the inner ring spacer 22 with a rotation gap. The other heat sink 49 b is exposed to the outer diameter surface from the hole of the outer peripheral wall 27 and is in close contact with the inner diameter surface of the outer ring spacer 23.

  During operation, the inner ring 17 of the rolling bearing 11 becomes hot relative to the outer ring 18, the heat of the inner ring 17 is conducted to the inner ring spacer 22, and the heat sink 49 a is heated by heat conduction from the inner ring spacer 22. The other heat sink 49b conducts heat at a relatively low temperature on the housing 15 side via the outer ring spacer 23. In order to prevent the heat of the inner ring 17 from affecting the outer ring spacer 23, it is desirable to form the casing 24 from a resin to block the heat. In the power generation unit 45, the thermoelectric element 48 self-generates due to the temperature difference between the heat sinks 49a and 49b generated during operation.

  As shown in FIG. 4, the electric power generated by the power generation unit 45 is charged in a capacitor 52 (preferably an electric double layer capacitor) mounted on the drive unit 46. The pump 47 is a micro pump such as a centrifugal type, a diaphragm type, or a gear pump type. The electric power generated by the power generation unit 45 is charged in the capacitor 52 and becomes a drive power source for the control circuit unit 53 of the drive unit 46. The control circuit unit 53 includes a control IC in which a program for refueling or the like is written, and a charge voltage detection circuit that measures the charge voltage of the capacitor 53. The charging voltage of the capacitor 52 is measured by the control circuit unit 53. The control circuit unit 53 appropriately controls the switching circuit 53 a and supplies the electric power charged in the capacitor 53 to the pump 47. The pump 47 is driven by the supplied power.

  When the charging voltage of the capacitor 52 reaches a predetermined voltage, the control circuit unit 53 controls the switching circuit 54 so that the power charged in the capacitor 52 is supplied to the pump 47 or simply discharged. May be.

  A suction tube 54 is connected to the suction port of the pump 47, and a discharge tube 55 is connected to the discharge port (see FIG. 2). The suction tube 54 is penetrated while holding the partition wall 34 in a liquid-tight manner, and is opened and communicated with the inside of the lubricating oil tank 35. In the discharge tube 55, a T-shaped joint 56 is interposed as a branch part in the middle (see FIG. 5), and branch discharge tubes 57 are connected to the branch ports divided into two sides of the T-shaped joint 56, respectively. Each branch discharge tube 57 is inserted into one end portion of the nozzle holes 43 and 43 provided to face each other in the axial direction (see FIG. 1).

  Instead of using the T-shaped joint 56 as a branching portion, one discharge tube 55 may be branched into two branches as it is to be divided into two branch discharge tubes 57.

  The bearing device of the first embodiment is as described above, and the operation thereof will be described next.

  When the machine tool spindle is driven, the lubricating oil tank 35 of the rolling bearing device 10 is preliminarily filled with lubricating oil, and the rolling bearings 11 and 11a are preliminarily filled with grease. When the operation of the machine tool spindle is continued and the temperature on the inner ring 17 side becomes relatively higher than the temperature on the outer ring 18 side, the heat is conducted to the inner ring spacer 22 and the outer ring spacer 23, and the heat sink 49a, A temperature difference occurs at 49b. The thermoelectric element 48 generates power due to the temperature difference, and the capacitor 52 is charged with the current.

  When a sensor (not shown) detects that the grease base oil (lubricating oil) in the rolling bearings 11 and 11a has decreased more than a certain level, the control circuit unit 53 controls the switching circuit 53a to charge the capacitor 52. The supplied electric power is supplied to the pump 47, and the pump 47 is driven.

  As another method, the charging voltage of the electric power generated by the power generation unit 45 and charged in the capacitor 52 is measured by the voltage detection circuit of the control circuit unit 53. When the charging voltage of the capacitor 52 reaches a predetermined voltage, the control circuit unit 53 controls the switching circuit 53a, supplies the electric power charged in the capacitor 52 to the pump 47, and drives the pump 47 to supply the lubricating oil. You may make it supply to the rolling bearings 11 and 11a. By comprising in this way, lubricating oil can be supplied even if it does not use the said sensor.

  In addition, the pump 47 is not driven to supply lubricating oil every time the capacitor 52 reaches a predetermined voltage, but the switching circuit 53a is controlled by the control circuit unit 53 even when the capacitor 52 reaches the predetermined voltage. The capacitor 52 is discharged by the discharge circuit separated from the capacitor. When the voltage reaches a predetermined voltage after repeating the charging and discharging a predetermined number of times, the switching circuit 53a may be controlled to drive the pump 47 with electric power. According to this method, the lubricating oil can be supplied over a long period of time, and the supply amount can be easily controlled.

  When the pump 47 is driven as described above, the lubricating oil in the lubricating oil tank 35 is sucked from the suction tube 54, and the sucked lubricating oil is discharged from the discharge tube 55 to the T-shaped joint 56, the branch discharge tube 57 and the nozzle. It is supplied to the inside of the rolling bearings 11 and 11a on both sides through the hole 43. Lubricating oil supplied inside penetrates into the grease, and lubrication is performed by the grease coming into contact with the rolling elements 19 and the cage 20.

  As described above, since the lubricating oil can be supplied to the two rolling bearings 11 and 11a by one set of the oil supply unit 13, the structure of the rolling bearing device 10 is simplified and the use efficiency of the oil supply unit 13 is improved. .

  In the illustrated case, a horizontal type is shown as the rotating shaft 14, but the rolling bearing device of the present invention can be applied to a vertical type as well. This also applies to the case of the second embodiment described below.

[Embodiment 2]
In the rolling bearing device 10 according to the second embodiment shown in FIG. 6, the member corresponding to the rotary shaft 14 is the fixed shaft 63. The fixed shaft 63 has a collar portion 63a corresponding to the collar portion 14a. The housing 15 and the pressing lid 61 integrated therewith are on the rotation side.

  The basic configurations of the rolling bearings 11 and 11a, the intermediate spacer 12, and the oil supply unit 13 are the same as those in the first embodiment. The difference is that the inner ring 17 and the inner ring spacer 22 are on the fixed side, the outer ring 18 and the outer ring spacer 23 are on the rotation side, and the oil supply unit 13 is attached to the inner ring spacer 22 side on the fixed side. is there. The inner ring 17 is a fixed ring, the inner ring spacer 22 is a fixed ring spacer, the outer ring 18 is a rotating ring, and the outer ring spacer 23 is a rotating ring spacer.

  The rolling bearings 11 and 11a are angular ball bearings in the same manner as described above, but are different in that they are so-called back-to-back, and the inclination of the oblique line a indicating the contact angle is opposite to that described above. ing. Therefore, the distance between the contact points B1 and B2 of the outer ring 17 is smaller than the distance between the contact points A1 and A2 of the inner ring 17.

Accordingly, the relationship between the axial length L23 of the outer ring spacer 23 interposed between both outer rings 18 and the axial length L22 of the inner ring spacer 22 interposed between the inner rings 17 is set to a relationship of L23> L22. By doing so, a predetermined bearing preload in the direction of the contact points A1 and A2 can be applied from the contact points B1 and B2 side as opposed to the above case.
Is done.

Since the configuration and operation of the oil supply unit 13 and the drive unit 46 are the same as those in the above case, the same parts are denoted by the same reference numerals and description thereof is omitted.
[Embodiment 3]

  In the rolling bearing device 10 according to the third embodiment shown in FIGS. 7 and 8, as in the case of the first embodiment, the rotating shaft 14 is on the rotating side, the housing 15 and the pressing lid 61 are on the fixed side, and the inner ring Reference numeral 17 denotes a rotating ring, outer ring 18 is a fixed ring, inner ring spacer 22 is a rotating ring spacer, and outer ring spacer 23 is a fixed ring spacer.

  The difference is that the rolling bearings 11 and 11a made of angular ball bearings are so-called back-to-back alignment, which is different from the case of Embodiment 1 in which front-to-back alignment is performed. The back-to-back alignment is the same as in the second embodiment (see FIG. 6).

  The inclination of the oblique line a indicating the contact angle is opposite to that in the first embodiment, and is in the same direction as in the second embodiment. The distance between the contact points B1 and B2 of the outer ring 17 is smaller than the distance between the contact points A1 and A2 of the inner ring 17. Accordingly, the relationship between the axial length L23 of the outer ring spacer 23 interposed between both outer rings 18 and the axial length L22 of the inner ring spacer 22 interposed between the inner rings 17 is set to a relationship of L23> L22. Thus, a predetermined bearing preload in the direction of the contact points A1 and A2 can be applied from the contact points B1 and B2 side.

  Further, in the case of the first embodiment, the casing 24 is provided with annular nozzles 31 on both side walls 28, and the nozzles 31 are provided with nozzle holes 43 (see FIG. 1). On the other hand, in the case of the third embodiment, the nozzle 31 as described above is not provided, and the casing 24 has a rectangular cross section formed by the inner peripheral wall 26, the outer peripheral wall 27, and the both side walls 28.

  Further, the point that the T-shaped joint 56 is connected to the discharge tube 55 and the branch discharge tube 57 is connected to each of the branch ports is the same, but in the case of the third embodiment, as shown in FIG. Each branch discharge tube 57 penetrates the both side walls 28 of the casing 24 and is inserted into the rolling bearings 11 and 11a on both sides. Further, a nozzle 58 is inserted and fixed at the tip of each branch discharge tube 57. The tip of each nozzle 58 is close to the cage 20 and the rolling element 19 of each rolling bearing 11, 11 a.

  By driving the pump 47, the lubricating oil in the lubricating oil tank 35 passes through the discharge tube 55, the T-shaped joint 56, and the branch discharge tube 57 from the nozzle hole (not shown) of each nozzle 58 to the inside of each bearing 11, 11 a. Supplied. The configurations and operations of the oil supply unit 13 and the drive unit 46 are the same as those in the first embodiment.

  As described above, the third embodiment has an advantage that the structure of the casing 24 is simplified because it is not necessary to provide the annular nozzles 31 on both sides of the casing 24.

DESCRIPTION OF SYMBOLS 10 Rolling bearing apparatus 11, 11a Rolling bearing 12 Middle spacer 13 Oil supply unit 14 Rotating shaft 14a Collar part 15 Housing 15a Step part 17 Inner ring 18 Outer ring 19 Rolling body 20 Cage 21 Seal member 22 Inner ring spacer 23 Outer ring spacer 24 Casing 25 peripheral groove 26 inner peripheral wall 27 outer peripheral wall 28 side wall 30 nut 31 nozzle 32 stepped portion 33, 34 partition wall 35 lubricating oil tank 41 inclined surface 43 nozzle hole 45 power generation unit 46 drive unit 47 pump 48 thermoelectric element 49a, 49b heat sink 50 screw 52 Capacitor 53 Control circuit portion 53a Switching circuit 54 Suction tube 55 Discharge tube 56 T-shaped joint 57 Branch discharge tube 58 Nozzle 61 Holding lid 62 Spacer 63 Fixed shaft 63a Collar portion

Claims (8)

A rolling bearing, a rotating ring spacer and a fixed ring spacer that are in contact with axial end surfaces of the rotating ring and the fixed ring of the rolling bearing, and an oil supply unit attached to the fixed ring spacer, respectively. The oil supply unit includes a casing, a lubricating oil tank provided in the casing, a pump, a power generation unit, and a driving unit for driving the pump, and a suction tube of the pump is disposed in the lubricating oil tank. A discharge tube is communicated with a nozzle provided toward the rolling bearing, a pair of the rolling bearings are arranged at intervals in the axial direction, and the rotating ring spacer and the fixed ring spacer are in contact with each other. Interposed between the bearings as intermediate spacers, the nozzles are respectively provided on both side walls of the casing, and the discharge tube is branched at the branching section. Tube is communicated with the nozzles respectively, the power generation unit, the rolling bearing apparatus characterized by being constituted by a thermoelectric device which generates power by temperature difference of the fixed wheel and the bearing rotating ring.   Each of the nozzles is provided to protrude on both side walls of the casing in an annular shape, and each of the nozzles is fitted to a stepped portion provided on a shoulder portion of a fixed ring of each rolling bearing. The rolling bearing device according to claim 1, wherein the branch discharge tube is connected to each of the provided nozzle holes.   2. The casing according to claim 1, wherein the casing is formed in an annular shape and is partitioned into a portion of the lubricating oil tank and a storage portion of the pump, the power generation unit, and the driving unit by partition walls provided at two circumferential positions. The rolling bearing device according to any one of items 1 to 2.   4. The rolling bearing device according to claim 1, wherein each of the pair of rolling bearings is an angular ball bearing. 5. The thermoelectric element is sandwiched by two heat sinks, the one of the heat sink is opposed at a rotational clearance to the rotary wheel spacers exposed from one of the peripheral wall of the casing and the other heat sink of the casing The rolling bearing device according to any one of claims 1 to 4 , wherein the rolling bearing device is exposed from the opposite peripheral wall and is in close contact with the fixed ring spacer. It said casing is made of resin, the rolling bearing device according to any of claims 1, characterized in that to block the heat is radiated to the fixed ring spacer from the rotating wheel by the casing 5. The drive unit includes a control circuit unit and a capacitor that charges a current supplied from the power generation unit, and the control circuit unit is configured to charge the capacitor when the lubricating oil in the rolling bearing has decreased more than a certain amount. Upon detecting that the voltage reaches a predetermined voltage, thereby discharging the capacitor, the rolling bearing device according to any one of 6 claim 1, characterized in that to drive the pump by its discharge current. The control circuit unit controls supply of electric power charged in a capacitor to the pump and switching to discharging, and supplies electric power charged in the capacitor to the pump when a predetermined number of times of charging and discharging is reached. The rolling bearing device according to claim 7 .

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