JP2004332928A - Bearing device and spindle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing device capable of stably performing continuous operation for a long period by successively discharging a supplied lubricant, securely discharging the lubricant to the outside of the bearing device, maintaining an excellent grease lubrication state by stably supplying grease for easy maintenance, and increasing the service life of a bearing, and a spindle device. <P>SOLUTION: This bearing device comprises a lubricant supply route for supplying the lubricant from the outside to the inside of an angular ball bearing 32 and discharge spacers 33 and 38 as rotating bodies disposed near the inner and outer rings on the side face of the angular ball bearing 32. The lubricant is discharged to the outside of the angular ball bearing 32 by the rotation of the discharge spacers 33 and 38. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bearing device and a spindle device used to support a spindle for a main shaft of a machine tool and the like.

As a bearing device for supporting a spindle for a main shaft of a machine tool or the like, oil lubrication such as jet lubrication, oil mist, oil air, or grease lubrication has been conventionally used. In recent years, with the increase in the speed of the spindle, lean lubrication in which a small amount of lubricating oil is intermittently attached to the raceway surface and rolling surface of a rolling bearing at a high speed intermittently as described in Patent Literature 1, and grease shown in Patent Literature 2 is intermittently used. A lubrication method for replenishing the rolling bearing space has been developed, and its performance for increasing the dmN to 1,000,000 or more (dm: pitch circle diameter of the rolling bearing (mm), N: rotational speed (min ^-1 )) has been improved.

  In a lubricating device that supplies or replenishes a lubricant such as lubricating oil or grease to the above-mentioned bearing (hereinafter, may be referred to as “supply”), it is necessary to appropriately discharge the supplied lubricant. This is an important factor to keep the agitation resistance of the lubricant during rotation low to avoid a rise in bearing temperature and torque.

  As one of countermeasures, as disclosed in Patent Document 3, a bearing device that discharges a lubricant supplied to the inside of the bearing to the outside of the bearing has been proposed. For example, in the bearing device 1 shown in FIG. 12, a storage space 12 for the discharged lubricant is formed in the outer race spacer 11.

  The bearing device 1 is configured to be able to periodically suck the lubricant stored in the discharge spaces 14 and 12.

  In FIG. 12, reference numeral 15 denotes a grease supply hole, 16 denotes a housing, 17 denotes an inner ring spacer, 18 denotes a ball, 19 denotes an outer ring, and 20 denotes an inner ring.

Further, the bearing device 2 shown in FIG. 13 is configured such that a seal member 21 is mounted on one side of the bearing 13 so that the lubricant flows to a wider space 22 on the opposite side of the seal member 21. Reference numeral 23 in FIG. 13 denotes an outer ring spacer.
JP 2001-315041 A JP 2003-113846 A JP 2003-232372 A

  However, the conventional bearing devices 1 and 2 (see FIG. 12 and FIG. 13) supply the lubricant further into the bearing space filled with the lubricant by continuous supply, thereby supplying the lubricant to the bearing devices 1 and 2. Since it is configured to be pushed out, the force for discharging the lubricant to the outside of the bearing is small.

  Therefore, it is not enough to fill the storage space 12 formed in the outer ring spacer 11 with the discharged lubricant, and there is a limit in continuing to supply the lubricant for a long time.

  Further, when the lubricant is discharged to the outside of the bearing devices 1 and 2 by suction from the outside of the bearing devices, further measures are required to remove all the lubricant inside the bearing devices 1 and 2.

  The present invention has been made in view of the above circumstances, and an object thereof is to continuously discharge a supplied lubricant, stably perform continuous operation for a long time, and to transfer a lubricant to the outside of a bearing device. It is an object of the present invention to provide a bearing device and a spindle device that can reliably discharge a lubricant, maintain a stable lubricating state by performing a stable replenishment of a lubricant that is easy to maintain, and can extend the life of the bearing. .

  The object of the present invention is achieved by the following configurations.

  (1) A lubricant supply path for supplying lubricant from the outside to the inside of the bearing, and a rotating body disposed near the inner and outer rings on the bearing side surface, and the lubricant is discharged to the outside of the bearing by rotation of the rotating body. A bearing device.

  (2) The bearing device according to (1), wherein the housing holding the bearing has a space for storing the discharged lubricant.

  (3) One or more discharge holes for discharging the lubricant from the space for storing the lubricant to the outside of the bearing device, and it is possible to store the lubricant in the discharge holes. The bearing device according to the above (2), which is characterized in that:

  (4) The bearing device according to any one of (1) to (3), wherein the rotating body is a collar formed in an inner ring spacer.

  (5) The bearing device according to any one of (1) to (3), wherein the rotating body is a collar formed on an inner ring.

  (6) The bearing device according to any one of (1) to (3), wherein the rotating body is a collar formed on a retainer.

  (7) The lubricant described in any one of (3) to (6), wherein the lubricant can be discharged by externally introducing a fluid other than the lubricant into the discharge hole. Bearing device.

(8) The bearing device according to any one of (1) to (7), wherein the lubricant is grease.
(9) A spindle device wherein a spindle for a machine tool spindle is supported by the bearing device according to any one of (1) to (8).
(10) A spindle device, wherein a high-speed motor spindle is supported by the bearing device according to any one of (1) to (8).

  According to the present invention, the lubricant that is supplied to the inside of the bearing and becomes unnecessary adheres to the rotating body formed as a rotating body disposed near the bearing, and this rotating body rotates with the shaft, The lubricant attached to the rotating body is repelled to the outside of the bearing by the rotational force, and the lubricant is forcibly and continuously discharged to the outside of the bearing. The lubricant is effective with both grease and oil, and also has the effect of reducing agitation resistance and suppressing heat generation.

  Further, since the storage space for the discharged lubricant is provided in the housing in the outer circumferential direction of the rotating body, the lubricant blown off by the rotating body can easily enter the storage space, and the storage space volume can be increased. .

  In addition, since the magnitude of the rotational force for flipping the lubricant changes according to the rotational speed of the main shaft, the amount of the supplied lubricant is small. At the time of low-speed rotation, the amount of the discharged lubricant is suppressed at the same time, so that an appropriate lubricant can be supplied according to the rotation speed.

  When the storage space is filled with the lubricant, it is necessary to discharge to the outside of the bearing device.According to the present invention, by externally introducing a fluid such as air into a discharge hole connected to the storage space provided in the housing, Since most of the lubricant can be discharged, maintenance can be easily performed.

  As described above, according to the present invention, the lubricant supplied to the inside of the bearing adheres to the rotating body disposed near the bearing, and is repelled to the outside of the bearing by the rotating force of the rotating body, so that the lubrication is performed. The agent is forcibly and continuously discharged out of the bearing.

  Further, since the storage space for the discharged lubricant is provided in the housing in the outer circumferential direction of the rotating body, the lubricant repelled by the rotating body can easily enter the storage space, and the storage space volume can be increased.

  In addition, since the magnitude of the rotational force that flies off the lubricant changes according to the rotational speed of the main shaft, the amount of lubricant supplied can be small, and at the time of low-speed rotation, the amount of lubricant discharged can be suppressed at the same time. Lubricants can be supplied.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The embodiment described below is suitably used for supporting a spindle for a machine tool spindle or a spindle for a high-speed motor such as an AC servomotor.

  (1st Embodiment)

  FIG. 1 shows an angular contact ball bearing device 3 according to a first embodiment to which the present invention is applied. The angular ball bearing device 3 includes an angular ball bearing 32, discharge spacers 33, 38 as rotating bodies disposed on the side surfaces of the angular ball bearing 32, and disposed in the vicinity of the inner and outer rings 42, 43. A shaft 45 and a housing 36 that supports the angular ball bearing 32 are provided.

  The angular contact ball bearing device 3 is formed in the outer ring spacer 34, a notch 35 formed at an end of the outer ring spacer 34, and a circumferential direction on the outer peripheral side of the notch 35 in the housing 36. And a lubricant storage space 37.

  As shown in FIG. 2, a plurality of the notches 35 are provided on the circumference of the outer ring spacer 34. As described above, by providing the plurality of cutouts 35 on the circumference, the efficiency of discharging the lubricant is improved.

  A gap 39 (δ1) is formed on the counter bore side between the outer ring 43 of the angular contact ball bearing 32 and the discharge flange 55 of the inner ring spacers 33, 38 in FIG. 1, and a gap 41 (δ2) is formed on the other side. Have been. Further, the housing 36 is provided with a lubricant supply path 31 for supplying a lubricant from the outside to the inside of the angular ball bearing 32. A lubricant storage space 40 is also formed on the side of the discharge spacers 33 and 38.

  In the angular contact ball bearing device 3, a lubricant supplied from the outside is supplied from the lubricant supply path 31 to the inside of the angular contact ball bearing 32, and stored in the inside of the angular contact ball bearing 32.

  Of the lubricant stored in the angular ball bearing 32, the lubricant that has come into contact with the discharge spacers 33, 38 is repelled to the outside of the angular ball bearing 32 by the rotational force of the discharge spacers 33, 38.

A discharge collar 55 is formed in the discharge spacers 33 and 38 so as to face the outer ring end face with gaps 39 (δ1) and 41 (δ2). The discharge collar 55 is provided at the end of the inner race spacers 33, 38 on the side of the angular ball bearing 32, and projects to the outer peripheral side of the inner race spacers 33, 38. The lubricant is discharged from the gaps 39 and 41 by the centrifugal force generated by the rotation of the discharge collar 55.
The discharge spacers 33 and 38 also discharge grease by the so-called slinger effect. Here, the slinger effect means that, in FIG. 1, the circumferential velocity of the spacer at point A and point A is different, and when the pressure of the air at point A decreases, the flow of air from point A to point A is reduced. The effect that occurs.
The present invention finds that this slinger effect is effective for discharging a lubricant such as grease, and has a configuration utilizing the effect.

  At this time, it is desirable that the gaps 39, 41 between the discharge collars 55, 55 and the end faces of the bearing outer ring are δ1, δ2 = 0.1 to 3 mm. If the gap is smaller than 0.1 mm, there is a possibility that resistance to the discharge of the lubricant may occur. If the gap is larger than 3 mm, the diameter of the collar becomes small, and the effect of centrifugal force is not sufficient. More preferably, δ1, δ2 = 0.2 to 2 mm. It is to be noted that slits, spiral grooves, or other irregularities for accelerating the fluidity of the lubricant may be provided on the bearing-side surfaces 46, 46 of the discharge collar.

  The lubricant blown off by the discharge spacer 33 passes through a notch 35 provided in the outer ring spacer 34, enters a lubricant storage space 37 provided in a housing 36, and is stored.

  The lubricant that cannot pass through the notch 35 passes through the gap 39 between the angular ball bearing 32 and the discharge spacer 33, and is stored in the lubricant storage space 40 between the discharge spacer 33 and the outer ring spacer 34. .

  The lubricant storage space 37 is a space provided in a groove shape in the inner diameter of the housing 36 and, together with the lubricant storage space 40, has a general life of 20,000 hours which is regarded as a general life of the lubricant in the machine tool spindle. Lubricant can be stored.

  In general, the volume of space required to store 20,000 hours of lubricant is approximately 33 ml when the amount of lubricant discharged at one time is 0.02 ml and the discharge interval is 12 hours. In the present invention, the total volume of both lubricant storage spaces 37 and 40 is 34 ml.

  In FIG. 1, when the shaft 45 is rotating at a high speed, the air inside the angular contact ball bearing 32 is pumped by the effect of the rotating shaft of the ball 44 and the pumping action caused by the internal shape and the contact angle of the bearing. Flows right from. Accordingly, since the lubricant is mainly discharged to the right side of the angular ball bearing 32, the discharge efficiency is good when the gap 39 is set to δ1 = 0.2 to 0.5 mm.

  In the drain spacer 38 on the left side in FIG. 1, since the lubricant is originally difficult to be discharged, the gap 41 may be larger than the gap 39, and even if (δ2> δ1) 36 has no lubricant storage space. Lubricant discharge is possible.

  As described above, in the angular ball bearing device 3 of the present invention, the lubricant filled in the inside of the angular ball bearing 32 adheres to the discharge spacers 33 and 38 which are arranged near the angular ball bearing 32 and formed as rotating bodies. However, since the discharge spacers 33 and 38 rotate together with the shaft 45, the lubricant attached to the discharge spacers 33 and 38 is repelled to the outside of the bearing by the centrifugal force of the rotational force, and the lubricant is forcibly removed. It is discharged continuously and continuously outside the bearing.

  Grease is used as the above-mentioned lubricant, which also has the effect of reducing the stirring resistance of the lubricant and suppressing heat generation. Further, a lubricating oil can be used as a lubricant.

  Further, since a lubricant storage space 37 for storing the lubricant discharged in the housing 36 in the outer circumferential direction of the discharge spacer 33 is provided, the lubricant blown off by the discharge spacer 33 enters the lubricant storage space 37. It is easy to enter and the storage space volume can be increased.

  Further, since the magnitude of the rotational force for flipping the lubricant changes according to the rotational speed of the shaft 45, the amount of the supplied lubricant is small. At the time of low-speed rotation, the amount of the discharged lubricant is suppressed at the same time, so that an appropriate lubricant can be supplied according to the rotation speed.

  (Second embodiment)

  FIG. 3 shows an angular contact ball bearing device 4 according to a second embodiment of the present invention. In the following embodiments, the same portions as those in FIG. 1 are denoted by the same reference numerals, and detailed description is omitted.

  In this angular contact ball bearing device 4, an angular contact ball bearing 50 is mounted in a rear combination. The space through which the lubricant should pass through the outer ring spacer 34 on the left side in FIG.

  As shown in FIGS. 4A and 4B, a plurality of holes 51 are provided in the outer ring spacer 34 in a radial manner. Thereby, the lubricant is efficiently discharged. A discharge collar 55 is formed in the discharge spacers 33 and 38, and the lubricant is discharged from the gaps 39 and 41 by centrifugal force accompanying rotation.

  In this embodiment, the discharge collar 55 of the discharge spacer 38 is formed to have a taper of θ = 0 to 45 °. Part of the lubricant supplied to the inside of the angular ball bearing 50 is discharged to the outside through the tapered surface 47 due to centrifugal force caused by rotation. The gap 41 'in a state where no taper is provided between the discharge collar 55, the end face of the bearing outer ring and the discharge collar 55 is designed and tapered by setting δ2' = 0.1 to 3 mm.

  The tapered surface does not necessarily have to be a conical surface, but may be a gently curved surface. Further, slits, spiral grooves, and other irregularities for accelerating the fluidity of the lubricant may be provided.

  Further, the discharge spacer 33 may have a tapered surface, the discharge spacer 38 may have a straight surface, or the discharge spacers 33 and 38 may have tapered surfaces. When both of the discharge spacers 33 and 38 are tapered, the angle θ of both the tapered surfaces may be the same, and the supply and discharge of lubricant and the flow of lubricant accompanying the rotation of the bearing are taken into consideration. May be different from each other.

  This angular ball bearing device 4 also has the same operation and effect as the angular ball bearing device 3 of the first embodiment.

  (Third embodiment)

  FIG. 5 shows an angular contact ball bearing device 6 according to a third embodiment of the present invention.

  In the angular ball bearing device 6, the discharge spacers 52a and 52b are formed as a separate member from the inner ring spacer 53. In this case, the discharge spacers 52a and 52b can be manufactured with a minimum amount of material, and low cost can be realized.

  The structures, functions and effects of the gaps 39 and 41 formed by the outer race 43 and the discharge spacers 52a and 52b, the notch 35 provided in the outer race spacer 34, and the lubricant storage space provided in the housing 36 are first and second. This is the same as the second embodiment.

  (Fourth embodiment)

  FIG. 6 shows an angular contact ball bearing device 7 according to a fourth embodiment to which the present invention is applied.

  In this angular ball bearing device 7, discharge flanges 55 and 55 'are provided on the inner ring 42 and the retainer 54 of the bearing 32 instead of the discharge spacer 33 of FIG. The discharge collar 55 provided on the inner race 42 is provided at an end of the inner race 42 opposite to the retainer 54 and protrudes toward the outer periphery of the inner race 42. A discharge collar 55 ′ provided on the holder 54 is provided at an end of the holder 54 and protrudes from an outer peripheral wheel of the holder 54. This discharge collar 55 ′ is arranged outside the bearing 32. These discharge collars 55 and 55 ′ are arranged with the bearing 32 interposed therebetween.

  The angular ball bearing device 7 does not need to affect the shape design of the inner ring spacer 53.

  Configuration and operation of outer ring 43, gaps 39 ', 41 formed by retainer discharge collars and discharge collars 55', 55, notch 35 provided in outer ring spacer 34, and lubricant storage space provided in housing 36. The effects are the same as those of the first to third embodiments.

  (Fifth embodiment)

  FIG. 7 shows a roller bearing device 8 according to a fifth embodiment to which the present invention is applied.

  This roller bearing device 8 uses a roller bearing 56 instead of the angular ball bearing 32 of the angular ball bearing device 3 shown in FIG.

  Gap 39, 41 formed by outer ring 56a of roller bearing 56 and discharge spacers 33, 38, notch 35 provided in outer ring spacer 34, configuration and operation / effect of lubricant storage space provided in housing 36. Is the same as in the first to fourth embodiments. Therefore, the roller bearing device 8 has the same operation and effect as the angular ball bearing device 3 shown in FIG.

  Although the first to fifth embodiments of the present invention show the case where the widths of the inner ring and the outer ring are the same, the present invention can be applied to the case where the widths of the inner ring and the outer ring are different. The same effect can be obtained by configuring the container discharge collar in the same manner.

  It is also possible to provide gaps 39, 41 for adjustment between the discharge spacer having the discharge collar and the inner ring end face, and the gaps 39, 41 are set between the discharge spacers 33, 38 and the outer ring spacer 34. In addition, the gaps 39 and 41 can be set using the discharge spacers 33 and 38 and the clearance adjustment spacers provided on the outer ring.

  (Sixth embodiment)

  FIG. 8 shows an angular ball bearing device 9 according to a sixth embodiment of the present invention. This angular contact ball bearing device 9 is provided with a lubricant storage hole 57 instead of the lubricant storage space 37 of FIG.

  A plurality of the lubricant storage holes 57 are provided radially. As a result, a space large enough to store the lubricant can be obtained.

  The configurations, functions and effects of the gaps 39 and 41 formed by the outer race 43 and the discharge spacers 33 and 38 and the notch 35 provided in the outer race spacer 34 are the same as those of the first to fifth embodiments.

  The operation and effect of the above configuration are also exerted in the following seventh and eighth embodiments.

  (Seventh embodiment)

  FIG. 9 shows a bearing device 60 according to a seventh embodiment to which the present invention is applied. In the bearing device 60, the lubricant stored in the lubricant storage space 37 of the housing 36 flows into the discharge hole 61 continuous with the lubricant storage space 37 and is stored therein.

  A plurality of discharge holes 61 are provided on the circumference, so that the volume of the lubricant storage space 37 can be increased.

  When the shaft 45 is installed in the horizontal direction, since there are a plurality of discharge holes 61 on the circumference, the discharge hole 61 is arranged below the lubricant storage space 37 regardless of how the phase of the housing 36 is set. it can. Therefore, there is an advantage that design and assembly are facilitated.

  (Eighth embodiment)

  FIG. 10 shows a spindle device 70 according to an eighth embodiment of the present invention. In the spindle device 70, a discharge hole 71 is provided in the housing 36. Further, a fluid inlet 72 is provided at one end of the discharge hole 71, and a lubricant outlet 73 is provided at the other end.

  The spindle device 70 has a function of performing maintenance by putting another fluid into the discharge hole 71 from the outside.

  Now, when the spindle device 70 is continuously used for a certain period of time and the lubricant fills the lubricant storage space 37 and the discharge hole 71 and can no longer be stored, maintenance is required.

  At this time, when the fluid is supplied from the fluid inlet 72, the lubricant stored in the angular ball bearing 32, the lubricant storage space 37, and the discharge hole 71 is washed away and discharged from the lubricant discharge port 73.

  The fluid inlet 72 and the lubricant outlet 73 may be reversed, and it is also possible to input fluid from both and discharge lubricant from both. After the old lubricant is discharged, the original lubrication performance can be exhibited without disassembling and reassembling the spindle device 70 by supplying new lubricant from the outside.

  If the lubricant supply function originally provided in the spindle device 70 is used to supply the lubricant from the outside, easier maintenance is possible. Further, a supply device for maintenance may be used.

  When the storage space is filled with the lubricant, it is necessary to discharge the lubricant to the outside of the bearing device.According to the present invention, by supplying a fluid from the outside to the discharge hole connected to the storage space provided in the housing. Since all of the lubricant can be discharged, maintenance can be easily performed.

  Examples of fluids used for maintenance include compressed air, cleaning fluids, oils, and combinations thereof.

  FIG. 11 (A) shows an initial grease filling amount of 15% of the bearing space volume under the test conditions of FIG. 11 (B) for the present invention having the structure of FIG. 1 and the conventional example of the structure of FIG. This is a result of continuous operation while supplying grease of the same lot as above at an interval of 0.02 ml / 7.5 min per bearing.

  In the configuration of the conventional example, the discharge of grease is not always sufficient, and the amount of grease in the bearing space of the angular ball bearing 32 may increase with time and an abnormal temperature rise may occur. Since the grease discharging function works, the remaining amount of the lubricant retained inside the angular contact ball bearing 32 is appropriately maintained, and the continuous operation can be performed for a long time.

FIG. 2 is a cross-sectional view illustrating the first embodiment of the present invention. It is a sectional view showing a notch of an outer ring spacer of a 1st embodiment of the present invention. It is a sectional view showing a second embodiment of the present invention. It is sectional drawing which shows the hole through which the lubricant of 2nd Embodiment of this invention penetrates. It is a sectional view showing a third embodiment of the present invention. It is a sectional view showing a fourth embodiment of the present invention. It is a sectional view showing a fifth embodiment of the present invention. It is sectional drawing which shows 6th Embodiment of this invention. It is sectional drawing which shows 7th Embodiment of this invention. It is a sectional view showing an 8th embodiment of the present invention. FIG. 9 is a diagram showing test results of the present invention and a conventional example. It is sectional drawing which shows a prior art example. It is sectional drawing which shows another conventional example.

Explanation of reference numerals

1, 2 bearing device 3 to 7, 9 angular contact ball bearing device 8 roller bearing device 11 outer ring spacer 11b discharge hole 12 storage space 13 bearing 14 space 15 discharge hole 17 outer ring spacer 19 storage space 21 seal member 22 space 35 Notch 31 Lubricant supply path 32 Angular contact ball bearing 33 Discharge spacer 34 Outer ring spacer 35 Notch 36 Housing 37 Lubricant storage space 38 Discharge spacer 39 Gap 40 Lubricant storage space 41 Gap 42 Inner ring 44 Ball 45 Shaft 46 Discharge Bearing side surface of collar 47 Tapered surface 51 Hole 52a, 52b Discharge spacer 53 Inner ring spacer 54 Cage 55 Collar (discharge collar)
56 Roller bearing 57 Lubricant storage hole 60 Bearing device 61 Discharge hole 70 Spindle device 71 Discharge hole 72 Fluid inlet 73 Lubricant discharge port

Claims (10)

A lubricant supply path for supplying lubricant from the outside to the inside of the bearing, and a rotating body disposed near the inner and outer rings on the side surface of the bearing,
A bearing device, wherein the lubricant is discharged to the outside of the bearing by rotation of the rotating body.   The bearing device according to claim 1, wherein a space for storing the discharged lubricant is provided in a housing that holds the bearing.   One or more discharge holes for discharging the lubricant from the space for storing the lubricant to the outside of the bearing device are provided, and the lubricant can be stored in the discharge holes. The bearing device according to claim 2.   The bearing device according to any one of claims 1 to 3, wherein the rotating body is a collar formed on an inner race spacer.   The bearing device according to any one of claims 1 to 3, wherein the rotating body is a collar formed on an inner ring.   The bearing device according to any one of claims 1 to 3, wherein the rotating body is a collar formed on a retainer.   The bearing device according to any one of claims 3 to 6, wherein the lubricant can be discharged by introducing a fluid other than the lubricant into the discharge hole from outside.   The bearing device according to any one of claims 1 to 7, wherein the lubricant is grease.   A spindle device, wherein a spindle for a machine tool spindle is supported by the bearing device according to any one of claims 1 to 8.   A spindle device, wherein a high-speed motor spindle is supported by the bearing device according to any one of claims 1 to 8.

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