JP2005106245A - Bearing with lubricating mechanism, and spindle device for machine tool using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing with a lubricating mechanism capable of substantializing high speed and a long service life by using only grease enclosed inside the bearing. <P>SOLUTION: On the bearing, a grease storage forming part 6 having a grease storing part 9 on an outer ring 2 is mounted. A pumping mechanism 7 for generating air flow toward the inner part from the outer part of the bearing by turning of the inner ring 2 is provided thereto. The pumping mechanism 7 comprises a step part 11 provided on the inner ring 2, and a gap forming part 6ba mounted on the outer ring 2 and opposed to the step part 11 through a gap d1. A discharge amount adjusting part 8 for restricting the flow of grease between the grease storing part 9 and a raceway surface is provided. A grease passing window 13 is provided on the outer diameter part of the discharge amount adjusting part 8. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a bearing with a lubrication mechanism for grease lubrication for a machine tool spindle and the like, and a spindle device for a machine tool using the same.

  As a lubrication method for machine tool spindle bearings, grease lubrication that can be used maintenance-free, air-oil lubrication in which lubricating oil is mixed with carrier air and oil is injected into the bearing from the nozzle, jet that injects lubricating oil directly into the bearing There are methods such as lubrication. In recent machine tools, in order to increase machining efficiency, there is a tendency for higher speed, and lubrication of main shaft bearings is also relatively inexpensive and air-oil lubrication that can be speeded up easily is often used. However, this air oil lubrication method has a problem from the viewpoints of cost, noise, energy saving, and resource saving because it is necessary for an air oil supply device as ancillary equipment and requires a large amount of air. There is also a problem of deteriorating the environment due to the scattering of oil. In order to avoid these problems, recently, speeding up by grease lubrication has begun to attract attention, and requests have been increasing.

  Since grease lubrication is performed only with the grease enclosed at the time of bearing assembly, high-speed operation leads to premature seizure due to deterioration of the grease due to bearing heat generation and oil film breakage on the raceway surface, particularly the inner ring. In particular, it is difficult to guarantee the grease life in a high-speed rotation region where the dn value exceeds 1 million (bearing inner diameter mm × rotational speed rpm).

New proposals have been introduced as a means of extending the life of grease. For example, there is a proposal (Patent Document 1) aiming at high speed and long life by providing a grease reservoir on the outer ring raceway surface portion. In addition, there is a proposal (Patent Document 2) in which a bearing is properly lubricated and lubricated by a grease replenishing device provided outside the spindle.
Japanese Patent Laid-Open No. 11-108068 JP 2000-113998 A

  However, the technologies of the above proposed examples are not satisfactory when considering the number of rotations used (> dn value 1.5 million) equivalent to air-oil lubrication and maintenance-free.

The present invention aims to solve these problems, and provides a bearing with a lubrication mechanism that can achieve high speed, long life, and maintenance-free operation using only the grease enclosed in the bearing. It is.
Another object of the present invention is to provide a spindle device for a machine tool that can achieve high speed, long life, and maintenance-free bearings.

A bearing with a lubrication mechanism according to the present invention is a rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements interposed between the raceways of the inner and outer rings, and is provided in contact with the outer ring and is a space between the raceways. A grease reservoir forming part having a grease reservoir portion that is axially opposed to the inner surface, and a grease that flows from the grease reservoir portion into the raceway surface of the inner ring and returns from the raceway surface of the outer ring to the grease reservoir portion, or a base oil flow thereof. And a grease flow generating means for generating a flow by rotation of the inner ring.
According to this configuration, the grease or its base oil sealed in the grease reservoir flows into the raceway surface of the inner ring from the grease reservoir by the action of the grease flow generating means by rotation of the inner ring, and the grease reservoir from the raceway surface of the outer ring. Return to the department. Thus, since the grease is circulated in the bearing and supplied, the following effects can be expected.
(1) Maintenance free.
(2) Lubrication corresponding to the number of rotations is possible, and high speed can be achieved.
(3) Since the grease or its base oil that has been used once is reused, the service life can be extended.
(4) With grease lubrication, the speed can be increased to the rotation range of air-oil lubrication, and the effects of cost reduction, noise reduction, energy saving, and prevention of environmental pollution can be expected compared to air-oil lubrication.

In the present invention, the grease flow generating means may be a pumping mechanism that generates an air flow from the outside to the inside of the rolling bearing.
When a pumping mechanism for generating an air flow by rotation of the inner ring is provided, an action of feeding grease into the bearing together with the air flow is generated. Such a pumping mechanism utilizes the rotation of the inner ring and thus can be obtained with a simple configuration.

  When the pumping mechanism is provided, a discharge amount adjustment that restricts the grease flow between the space between the raceway surface and the grease reservoir by the gap between the inner surface facing the outer surface of the inner ring and the inner ring A part may be provided, and a grease passage window may be provided in the outer diameter portion of the discharge amount adjusting part. When this discharge amount adjusting component is provided, the amount of air flow generated by the pumping mechanism can be adjusted by appropriately designing the gap distance between the inner diameter surface and the inner ring, the gap length, and the like. The grease passage window in the outer diameter portion of the discharge amount adjusting component serves as a grease flow path that returns from the raceway surface of the outer ring to the grease reservoir.

The pumping mechanism is provided, for example, on a stepped portion provided on the outer diameter surface of an inner ring or an annular part adjacent to the inner ring and having a large diameter on the bearing inner side, and provided on a part attached to the outer ring and provided with a gap between the stepped portion. You may comprise by the clearance gap formation part which opposes via.
When such a step portion is provided and a gap is formed along the step portion, a pumping action can be generated by the action of centrifugal force using the speed difference due to the radial position in the gap. In this way, the pumping mechanism can be provided with a simple configuration in which only the step portion and the gap forming portion are provided.

  The gap forming portion may be an inner diameter portion of a grease reservoir forming component. When the gap forming portion is provided in the grease reservoir forming component, the grease reservoir portion and the gap forming portion can be obtained with one component, so that the configuration is further simplified and the number of components can be reduced, resulting in a compact configuration.

In the present invention, when the discharge amount adjusting component is provided, a step surface is provided immediately below the rolling elements following the raceway surface of the inner ring, and the outer diameter surface portion on the grease reservoir side of the inner ring is tracked from the step surface of the inner ring. A grease flow gap may be formed between the end surface of the inner peripheral portion of the discharge amount adjusting component and the step surface.
When a step is formed in the inner ring directly under the rolling elements and the end face of the discharge adjustment component is brought close to form a grease flow gap, the grease or its base oil sent by the pumping mechanism is guided to the raceway surface of the inner ring from the grease flow gap. The Therefore, the grease or its base oil fed by the pumping action is efficiently lubricated to the raceway surface without escaping to the places where lubrication is not required.

Further, when the discharge amount adjusting component is provided, a stepped portion having a small diameter on the width side immediately below the discharge amount adjusting component may be formed on the outer diameter surface of the inner ring.
By providing the stepped portion in this way and making the width side of the inner ring outer diameter surface small, the space around the grease reservoir is expanded and the amount of grease filled can be increased. Therefore, the lifetime can be further extended. Since the step portion is provided directly under the discharge amount adjusting component, the grease flow due to the pumping action is not hindered even if there is a step.

When providing a discharge amount adjusting component, a tapered surface portion having a large diameter on the raceway surface is provided on the outer diameter surface of the inner ring directly below the discharge amount adjusting component, and a gap is formed between the inner surface of the discharge amount adjusting component and the tapered surface portion of the inner ring. You may provide the taper surface part which faces through.
In this way, by providing a tapered surface facing the inner ring and the discharge amount adjusting component to form a tapered gap, a pumping action is generated in this gap, and the grease flows more easily on the raceway surface.

  In the present invention, the grease reservoir forming component may be a component that fits into the inner diameter surface of the outer ring. In this configuration, since the grease reservoir forming component is incorporated into the rolling bearing, it is excellent in handleability such as incorporation and transportation of the bearing. If the width of the outer ring of the bearing is increased to incorporate a grease reservoir forming component, heat conduction is improved and heat dissipation of the bearing is improved.

  In this invention, the grease reservoir forming component may be a component adjacent to the width surface of the outer ring. If the grease reservoir is provided adjacent to the outer ring, the outer ring can have the same width as a normal bearing, and the productivity is excellent.

  In the present invention, the rolling bearing may be any of an angular ball bearing, a deep groove ball bearing, a cylindrical roller bearing, a tapered roller bearing, and the like. When the rolling bearing is an angular ball bearing and the grease reservoir forming component is provided on the back side of the bearing, due to the movement characteristics of grease or its base oil at the inner diameter of the outer ring of the angular ball bearing, The used grease on the raceway surface is recovered well in the grease reservoir.

In this invention, when the grease reservoir is provided, the rolling bearing may be a cylindrical roller bearing, and the end of the discharge amount adjusting component may be located on the inner diameter side of the cage that holds the rolling elements. .
With cylindrical roller bearings, it is not possible to guide the grease by providing a step directly under the rolling element, but by providing a discharge adjustment component that extends to the inner diameter side of the cage, no grease is required by guiding the discharge adjustment component. The raceway is efficiently lubricated without escaping to the part.

A spindle device for a machine tool according to the present invention is a spindle device in which a main shaft is rotatably supported in a housing by a plurality of rolling bearings, and a part or all of these rolling bearings are lubricated by any of the above-described configurations in the present invention. It is a bearing.
As described above, since the machine tool is strongly required to have a high speed, a long service life, and a maintenance-free operation, each effect of the bearing with a lubrication mechanism of the present invention is effectively exhibited.

In the spindle device for a machine tool according to the present invention, when the grease flow generating means of the bearing with the lubrication mechanism is a pumping mechanism that generates an air flow from the outside to the inside of the rolling bearing, in the space between the main shaft and the housing. You may provide the communicating path which connects the space part of the both sides of a bearing with a lubrication mechanism.
If there is a pressure difference in the space on both sides of the bearing, it will hinder the pumping action by the pumping mechanism, but the pressure difference can be eliminated by providing the communication hole.

The bearing with a lubrication mechanism according to the present invention includes a grease reservoir forming part that is provided in contact with an outer ring and that forms a grease reservoir portion facing the axial direction in a space between the raceway surfaces, and the grease reservoir portion from the grease reservoir portion to the raceway surface of the inner ring. It has grease flow generation means that generates grease flow that is the flow of grease or its base oil from the raceway surface of the flowing outer ring to the grease reservoir by rotation of the inner ring, so that only the grease enclosed in the bearing is used. High speed, long life, and maintenance-free can be achieved.
The spindle device for a machine tool according to the present invention can achieve high speed, long life, and maintenance-free bearings. As a result, improvement in processing performance and processing quality can be obtained. In addition, since it is grease lubrication, it is excellent in terms of low cost, low noise, energy saving, resource saving, and environment.

  A first embodiment of the present invention will be described with reference to the drawings. In FIG. 1, this bearing with a lubrication mechanism is a rolling bearing having a plurality of rolling elements 3 interposed between raceways 1a and 2a of an inner ring 1, an outer ring 2, and inner and outer rings 1 and 2, and a grease reservoir forming component. 6, a pumping mechanism 7 serving as a grease flow generating means, and a discharge amount adjusting component 8. The plurality of rolling elements 3 are held by a cage 4, and one end of the bearing space between the inner and outer rings 1 and 2 is sealed with a seal 5. The rolling bearing serving as the bearing with the lubrication mechanism of this embodiment is an angular ball bearing, the seal 5 is provided at the front end, and the grease reservoir forming component 6 and the pumping mechanism 7 are provided on the back side. In the figure, the crossed hatched portions indicate portions filled with grease.

  The grease reservoir forming component 6 is a ring-shaped component in which a grease reservoir portion 9 facing the axial direction is formed in the space between the raceway surfaces 1 a and 2 a of the inner and outer rings 1 and 2, and is provided in contact with the outer race 2. In this example, the length from the center of the raceway surface 2a of the outer ring 2 to the width surface where the seal 5 is provided is made longer than the width surface at the other end, and a grease reservoir is provided in the outer ring inner diameter surface portion of the elongated portion. The forming component 6 is fitted. In this case, the inner and outer rings 1 and 2 have the same width dimension, the width dimension is larger than the standard dimension in one direction, and the inner diameter surface of the portion where the width dimension of the outer ring 2 is increased is as described above. The grease reservoir forming component 6 is fitted. Further, a discharge amount adjusting component 8 is fitted adjacent to the grease reservoir forming component 6 on the inner diameter surface of the portion where the width dimension of the outer ring 2 is increased, and the grease reservoir forming component 6 and the discharge amount adjusting component 8 are The grease reservoir 9 is formed in a partitioned space.

  The discharge amount adjusting component 8 has an inner diameter surface 8b facing the outer diameter surface 1b of the inner ring 1, and a ring shape that restricts the grease flow by a gap d2 between the inner diameter surface 8b and the outer diameter surface 1b of the inner ring 1. It is a part of. The discharge amount adjusting component 8 is engaged with an engaging step 2 c formed on the inner diameter surface 2 b of the outer ring 2, and the grease reservoir forming component 6 and the discharge amount adjusting component 8 are overlapped with each other. It is fixed in the axial direction by a retaining ring 10 that engages with the retaining ring groove. In this way, the discharge amount adjusting component 8 is interposed between the space between the raceway surfaces 1 a and 2 a and the grease reservoir 9. Adjacent portions of the grease reservoir forming component 6 and the discharge amount adjusting component 8 are provided with a sealing component 12 such as an O-ring between the outer diameter surface and the outer ring inner diameter surface to prevent grease leakage.

The pumping mechanism 7 flows a grease flow (arrow b), which is a flow of grease or its base oil, flowing from the grease reservoir 9 into the raceway surface 1a of the inner ring 1 and returning from the raceway surface 2a of the outer ring 2 to the grease reservoir 9. It becomes a grease flow generating means generated by rotation. The pumping mechanism 7 generates the grease flow b by generating an air flow a from the outside to the inside of the rolling bearing.
The pumping mechanism 7 includes a step portion 11 provided at an end portion of the outer diameter surface of the inner ring 1 and having a large diameter on the bearing inner side, and a gap forming portion 6ba facing the step portion 11 via a gap d1. The gap forming portion 6ba is composed of an inner diameter portion of the grease reservoir forming component 6.
The pumping mechanism 7 also functions as a bearing sealing means by its pumping action.

  The grease reservoir forming component 6 includes an outer peripheral cylindrical portion 6a, a flange portion 6b extending from the outer end of the outer peripheral cylindrical portion 6a to the inner diameter side, and a partition cylindrical portion 6c extending from the radial intermediate portion of the inner surface of the flange portion 6b to the bearing inner side. The inner diameter end of the flange portion 6b becomes the gap forming portion 6ba.

  The inner ring 1 is provided with a step surface 1c immediately below the rolling element 3 following the raceway surface 1a, and a portion of the outer diameter surface 1b on the grease reservoir 9 side of the inner ring 1 from the step surface 1c is a raceway surface 1a. The diameter is smaller than that. A grease flow gap d3 is formed between the step surface b and the end surface of the inner peripheral portion 8a of the discharge amount adjusting component 8. The inner peripheral portion 8 a of the discharge amount adjusting component 8 extends in a cylindrical shape toward the inside of the bearing, extends directly below the cage 4, and further extends directly below the rolling element 3. The innermost end face faces the step surface 1c. The inner diameter surface 8b of the discharge amount adjusting component 8 is a cylindrical surface.

The operation of the above configuration will be described. At the time of assembling the bearing, grease is filled in the grease reservoir 9 so as to become full. During use, the grease adhering to the outer diameter surface of the inner ring is peeled off by centrifugal force due to the rotation of the inner ring 1, and a space is created between the grease in the grease reservoir 9 and the outer diameter surface 1b of the inner ring. Due to the pumping action of the pumping mechanism 7 in the space, an air flow is generated toward the inside of the bearing, and a force is generated in which the grease or its base oil is pushed by the air flow and moves into the bearing.
The pumping mechanism 7 includes a step portion 11 provided at the end portion of the inner ring 1 and a gap forming portion 6ba provided in the outer ring 2, and constitutes a gap d1 along the step portion 11. The pumping action is generated by the action of the centrifugal force due to the speed difference due to the radial position in the gap d1 caused by the rotation of 1. That is, a force for sucking air into the bearing from the outside of the bearing is generated.

  The grease or its base oil pushed into the bearing by the air flow flows into a gap d2 formed by the discharge amount adjusting component 8 and the inner ring outer diameter surface. The gap amount and the gap construction length here have a function of adjusting the amount of grease or its base oil supplied to the inside of the bearing, and are adjusted according to the required oil supply amount. This adjustment is made at the design stage. The quantity-adjusted grease or its base oil is supplied toward the raceway surface 1a of the inner ring 1 and the rolling element 3 from the end surface portion located immediately below the rolling element of the discharge amount adjusting component 8, and is supplied as bearing lubricating oil. Will be.

Most of the grease used for lubrication or its base oil is moved to the back side by the rolling element 3 that rolls at a contact angle, and the discharge amount adjusting component 8 interposed between the back side and the grease reservoir 9 is provided. From the grease passage window 13 to the grease reservoir 9.
That is, the grease in the bearing or its base oil adheres to the surface of the grease reservoir 9 → the inner diameter surface of the discharge amount adjusting component 8 → the end surface of the discharge amount adjusting component 8 → the inner ring raceway surface 1 a → the rolling element 3 (for lubrication). (Contribution) → Outer ring raceway surface 2a → Grease is supplied through a route of grease reservoir 9.

  The grease or its base oil supplied between the raceway surfaces 1a and 2a of the inner and outer rings 1 and 2 and used for lubrication is used when the rolling element 3 rolls with a contact angle like an angular ball bearing. Although the action of movement to the back side is likely to occur, even if the contact angle is not provided, if the bearing space is sealed with the seal 5, it is less likely to move to the back side than the space between the raceway surfaces 1a and 2a. When the grease is supplied from the inner diameter side by the pumping mechanism 7, there is an action of returning to the grease reservoir 9 side where an extra space is generated by the grease supply.

According to the bearing with a lubrication mechanism having this configuration, since the grease is circulated in the bearing and supplied, the following effects can be expected.
(1) Maintenance free.
(2) Lubrication corresponding to the number of rotations is possible, and high speed can be achieved.
(3) Since the grease or its base oil that has been used once is reused, the service life can be extended.
(4) With grease lubrication, the speed can be increased to the rotation range of air-oil lubrication, and the effects of cost reduction, noise reduction, energy saving, and prevention of environmental pollution can be expected compared to air-oil lubrication.

  In this embodiment, as the grease flow generating means, the pumping mechanism 7 that generates the air flow from the outside of the bearing toward the inside by the rotation of the inner ring 1 is used, so that the grease flow b can be generated with a simple configuration. In particular, the pumping mechanism 7 includes a step portion 11 provided on the inner ring 7 and a gap forming portion 6ba attached to the outer ring, and thus has a simpler configuration. Since the gap forming portion 6ba is composed of the inner diameter portion of the grease reservoir forming component 6, the grease reservoir 9 and the gap forming portion 6ba can be obtained as a single component, so that the number of components can be reduced and a compact configuration can be obtained.

The pumping force can be adjusted by adjusting the height of the step portion 11 and the gap amount of the gap d1. Further, since the discharge amount adjusting component 8 is provided, the amount of air flow generated by the pumping mechanism can be adjusted by appropriately designing the amount of gap between the inner diameter surface and the inner ring outer diameter surface, the length of the gap, and the like.
The grease or its base oil delivered by this pumping action is provided with a stepped surface 1c immediately below the rolling elements of the inner ring 1, and the end face of the discharge amount adjusting component 8 is brought close to form a grease flow gap d3. To the inner ring raceway surface 1a. For this reason, the grease fed by the pumping action is efficiently lubricated to the raceway surface 1a without escaping to a place where lubrication is unnecessary.

  Furthermore, in this embodiment, since the width dimensions of the inner and outer rings 1 and 2 are the same, it is easy to manage the difference in plane, and the width dimension of these inner and outer rings 1 and 2 is larger than the standard dimension. The effect of reducing the temperature rise during operation due to the increase in the heat radiation area from the can is obtained.

FIG. 2 shows another embodiment of the present invention. In this embodiment, a step 15 for expanding the space is formed on the outer diameter surface of the inner ring 1 directly below the discharge amount adjusting component 8 and the inner ring width surface side has a small diameter. Since the inner ring thickness on the end side of the stepped portion 15 is reduced by forming the stepped portion 15, the stepped portion 11 of the pumping mechanism 7 is formed by the annular ridge 16 provided on the outer diameter surface of the inner ring 1. ing. In other words, the inner diameter outer diameter surface portion between the step portion 15 for expanding the space and the annular protrusion 16 is an annular groove.
By providing the step portion 15 for expanding the space and making the end portion of the inner ring outer diameter surface 1b have a small diameter in this way, the peripheral space of the grease reservoir portion 9 can be expanded and the amount of grease filled can be increased. Therefore, the lifetime can be further extended. Since the step portion 15 is provided immediately below the discharge amount adjusting component 8, even if there is a step, the grease flow by the pumping mechanism 7 is not hindered. Moreover, although the pumping mechanism 7 forms the level | step-difference part 11 with the cyclic | annular protrusion 16, the pumping effect | action is acquired similarly to the case of 1st Embodiment. Other configurations and effects in this embodiment are the same as those in the first embodiment.

FIG. 3 shows still another embodiment of the present invention. In this embodiment, as shown in a box B in the figure, a tapered surface portion 1ba having a large diameter on the raceway surface 1a side is provided on the outer diameter surface of the inner ring 1, and the inner ring 8b of the discharge amount adjusting component 8 is provided on the inner ring surface 8b. One tapered surface portion 1ba is provided with a tapered surface portion 8ba facing each other through a gap. The taper angle α of the taper surfaces 1ba and 8ba is preferably in the range of 10 to 15 °. The step portion 11 of the pumping mechanism 7 is formed by an annular protrusion 16 provided on the outer diameter surface of the inner ring 1 as in the embodiment of FIG.
In the case of this configuration, a pumping action due to the rotation of the inner ring 1 occurs in the gap between the inner ring 1 and the tapered surfaces 1ba, 8ba of the discharge amount adjusting component 8. Therefore, the grease is more easily sent to the inner ring raceway surface 1a. Other configurations and effects in this embodiment are the same as those in the first embodiment.

In each of the above embodiments, the grease reservoir forming component 6 is fitted to the inner diameter surface of the outer ring 2. However, as shown in FIG. 4, the grease reservoir forming component 6 is a component adjacent to the width surface of the outer ring 2. Also good. In this case, the outer diameter of the grease reservoir forming component 6 is the same as that of the outer ring 2, and the grease reservoir forming component 6 is fitted to the inner diameter surface of a housing (not shown) to which the outer ring 2 is fitted. The grease reservoir forming component 6 is formed with a fitting recess 17 having the same diameter as the inner diameter surface of the outer ring 2 on the side surface on the outer ring side, and the discharge amount adjusting component 8 is formed on the outer ring 2 and the fitting recess 17 of the grease reservoir forming component 6. It fits across. The inner ring 1 has the same width as the outer ring 2, and the stepped portion 11 constituting the pumping mechanism 7 is formed on the outer diameter surface of the annular component 18 adjacent to the inner ring 1.
When the grease reservoir forming component 6 is a component adjacent to the width surface of the outer ring 2 as described above, the outer ring 2 can have a normal standard width and is excellent in mass productivity. Other configurations and effects in this embodiment are the same as those in the first embodiment shown in FIG.

FIG. 5 shows a bearing with a lubrication mechanism according to the embodiment shown in FIG. 2, in the same manner as the example of FIG. 4, the grease reservoir forming component 6 is a component adjacent to the width surface of the outer ring 2 and the pumping mechanism is adjacent to the inner ring 1. 6 is provided with an annular part 18 having a stepped portion 11 of FIG. 7. In the bearing with a lubrication mechanism of the embodiment shown in FIG. An annular part 18 having a step 11 of the pumping mechanism 7 adjacent to the inner ring 1 is provided as a part adjacent to the width surface.

4 to 5, the inner ring 1 and the outer ring 2 have the same width. However, as shown in FIG. 7, for example, the outer ring 2 is wider than the inner ring 1 and is widened. The grease reservoir forming component 6 may be fitted to the inner surface of the outer ring, and the annular component 18 having the step portion 11 may be provided adjacent to the width surface of the inner ring 1.
On the contrary, as shown in FIG. 8, the inner ring 1 is wider than the outer ring 2, a grease reservoir forming component 6 is fitted adjacent to the width surface of the outer ring 2, and a step portion 11 is provided on the inner ring 1. May be.
7 and FIG. 8 are different in the width of the inner ring 1 or the outer ring 2 in the embodiment shown in FIG. 1, but also in each embodiment shown in FIG. 2 or FIG. Similarly to the example, the inner ring 1 and the outer ring 2 may have different widths, and either the grease reservoir forming component 6 or the adjacent annular component 18 may be adjacent to the width surface.

Each of the above embodiments is an example applied to an angular ball bearing. However, the bearing with a lubrication mechanism of the present invention can also be applied to a cylindrical roller bearing as shown in FIGS. .
Each of these examples of FIGS. 9 to 11 is obtained by replacing the part of the rolling bearing formed by the inner and outer rings 1 and 2 and the rolling element 3 with a cylindrical roller bearing in each of the examples shown in FIGS. . However, the discharge amount adjusting component 8 is not fitted to the outer ring 2 but fitted to the fitting recess 17 provided in the grease reservoir forming component 6. The inner peripheral portion 8 a of the discharge amount adjusting component 8 is assumed to extend in the width direction so that the end portion on the bearing side is located on the inner diameter side of the cage 4. The grease reservoir forming component 6 may be formed by a combination of a plurality of components 6A and 6B as in the example of FIG. Also in each of the above embodiments, the grease reservoir forming component 6 may be constituted by a plurality of components as described above. Other configurations in the examples of FIGS. 9 to 11 are the same as those of the examples shown in FIGS.

  Even when applied to the cylindrical roller bearing in this way, the grease or its base oil sealed in the grease reservoir 6 flows into the inner ring raceway surface 1a from the grease reservoir 9 by the action of the pumping mechanism 7 by the rotation of the inner ring 1. The grease circulation action of returning from the outer ring raceway surface 2a to the grease reservoir 9 and its effects can be expected.

  In each of the examples of FIGS. 9 to 11, the grease reservoir forming component 6 is adjacent to the outer ring 2. However, in the case of these cylindrical roller bearings, the outer ring 2 is similar to the embodiment of FIGS. 1 to 3. Alternatively, the grease reservoir forming component 6 may be fitted to the inner diameter surface of the outer ring 2.

  In each of the above embodiments, the grease flow generating means is composed of the pumping mechanism 7. However, the grease flow generating means is not limited to this. The grease flow generating means flows from the grease reservoir 9 into the inner ring raceway surface 1a and the raceway surface of the outer ring 2. Any grease can be used as long as it can cause the grease flow returning from 2a to the grease reservoir 9 by the rotation of the inner ring 1.

  FIG. 12 shows an example of a machine tool spindle device according to an embodiment of the present invention. In this spindle apparatus, the main shaft 21 is rotatably supported in a housing 22 by a plurality of rolling bearings 23, 24, and some or all of the rolling bearings 23, 24 are used as bearings with a lubrication mechanism according to the present invention. For example, it is a bearing with a lubrication mechanism shown in any of FIGS. In the illustrated example, both ends of the main shaft 21 are supported by two rolling bearings 23 and 24, and the bearings with a lubrication mechanism according to the embodiment of FIG. 1 are used for these rolling bearings 23 and 24. Moreover, these two rolling bearings 23 and 24 are angular ball bearings, and are a back surface combination.

  Spaces S1, S2, and S3 between the main shaft 21 and the housing 22 on both sides of the rolling bearings 23 and 24, which are bearings with respective lubrication mechanisms, are communicated with each other through a communication path 25 that is provided in the housing 22 and includes a hole.

The inner ring 1 of each rolling bearing 23, 24 is positioned by an inner ring positioning spacer 26, an inner ring spacer 27, and an inner ring fixing spacer 28, and is fastened and fixed by an inner ring fixing nut 29. The outer ring 2 is positioned and fixed by an outer ring spacer 30 and outer ring pressing lids 31 and 32. The housing 22 is formed by fitting the housing inner cylinder 22A and the housing outer cylinder 22B, and an oil passage 33 for cooling is provided in the fitting portion.
The main shaft 21 is provided with a chuck (not shown) for detachably attaching a tool or a work (not shown) to the front end 21a, and the rear end 21b transmits rotation to a drive source such as a motor. They are connected via a mechanism (not shown). The motor may be built in the housing 22. The spindle device can be applied to various machine tools such as a machining center, a lathe, a milling machine, and a grinding machine.

  According to the spindle device for a machine tool with this configuration, the effects of speeding up, extending the service life, and making maintenance-free in the bearing with a lubrication mechanism of the present invention are effectively exhibited. In addition, if there is a pressure difference between the spaces on both sides of the rolling bearings 23 and 24, which are bearings with a lubrication mechanism, the pumping action by the pumping mechanism 7 is obstructed. However, by providing the communication hole 25, the pressure difference is eliminated. A constant air pressure is maintained, and a good pumping action is maintained.

  In the embodiment of FIG. 12, the rolling bearings 23 and 24 that support the main shaft 21 are angular ball bearings. For example, the front end side of the main shaft 21 is supported by a pair of angular ball bearings, and the rear end side is a cylindrical roller bearing. You may make it support. In that case, you may use the bearing with a lubrication mechanism of this invention for each bearing.

It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning a 1st embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiments of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is a fragmentary sectional view of the bearing with a lubrication mechanism concerning other embodiment of this invention. It is sectional drawing of the spindle apparatus for machine tools concerning embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Inner ring 1ba ... Tapered surface part 1c ... Step surface 2 ... Outer ring 1a, 2a ... Raceway surface 3 ... Rolling element 4 ... Cage 5 ... Seal 6 ... Grease reservoir forming part 6ba ... Gap forming part 7 ... Pumping mechanism 8 ... Discharge amount Adjustment part 8ba ... Tapered surface part 9 ... Grease reservoir part 11 ... Step part 13 ... Grease passage window 15 ... Step part d1 to d3 ... Gap

Claims (14)

  A rolling bearing having an inner ring, an outer ring, and a plurality of rolling elements interposed between the raceways of the inner and outer rings, the grease reservoir provided in contact with the outer ring and facing the space between the raceways in the axial direction And a grease reservoir forming component that forms a grease flow that flows from the grease reservoir portion into the raceway surface of the inner ring and returns from the raceway surface of the outer ring to the grease reservoir portion, or a grease flow that is the flow of its base oil, by rotation of the inner ring. A bearing with a lubrication mechanism, characterized by comprising a flow generating means.   2. The bearing with a lubrication mechanism according to claim 1, wherein the grease flow generating means is a pumping mechanism that generates an air flow from the outside to the inside of the rolling bearing.   The discharge amount adjusting part for restricting a grease flow is provided between the space between the raceway surfaces and the grease reservoir in the gap between the inner ring and the inner ring facing the outer ring surface of the inner ring. A bearing with a lubrication mechanism in which a grease passage window is provided in the outer diameter portion of the discharge amount adjusting component.   4. The pumping mechanism according to claim 2, wherein the pumping mechanism is provided in a step portion provided on an outer diameter surface of an inner ring or an annular part adjacent to the inner ring and having a large diameter inside the bearing, and a part attached to the outer ring. A bearing with a lubrication mechanism comprising a gap forming portion facing the stepped portion via a gap.   The bearing with a lubrication mechanism according to claim 4, wherein the gap forming portion is an inner diameter portion of the grease reservoir forming component.   6. The method according to claim 3, wherein a stepped surface is provided immediately below the rolling elements following the raceway surface of the inner ring, and an outer diameter surface portion on the grease reservoir side of the stepped surface of the inner ring is defined as the track surface. A bearing with a lubrication mechanism, which has a smaller diameter than that and has a grease flow gap formed between the end surface of the inner peripheral portion of the discharge amount adjusting component and the step surface.   6. The bearing with a lubrication mechanism according to claim 3, wherein a step portion having a small diameter on the inner ring width surface side is formed directly on the outer diameter surface of the inner ring directly below the discharge amount adjusting component.   6. The taper portion according to claim 3, wherein a tapered surface portion having a large diameter on the raceway side is provided on an outer diameter surface of the inner ring directly below the discharge amount adjusting component, and an inner diameter surface of the inner ring is provided on the inner diameter surface of the discharge amount adjusting component. A bearing with a lubrication mechanism provided with a tapered surface portion facing the tapered surface portion through a gap.   9. The bearing with a lubrication mechanism according to claim 1, wherein the grease reservoir forming component is a component fitted to the inner diameter surface of the outer ring.   9. The bearing with a lubrication mechanism according to claim 1, wherein the grease reservoir forming component is a component adjacent to the width surface of the outer ring.   11. The bearing with a lubrication mechanism according to claim 1, wherein the rolling bearing is an angular ball bearing, and the grease reservoir forming component is provided on the back side of the bearing.   11. The rolling bearing according to claim 3, wherein the rolling bearing is a cylindrical roller bearing, and an end portion of an inner peripheral portion of the discharge amount adjusting component is positioned on an inner diameter side of a cage that holds the rolling element. Bearing with lubrication mechanism.   13. A spindle device for a machine tool in which a main shaft is rotatably supported in a housing by a plurality of rolling bearings, and a part or all of these rolling bearings are combined with a bearing with a lubrication mechanism according to any one of claims 1 to 12. Spindle device for machine tools.   14. The grease flow generating means of the bearing with a lubrication mechanism according to claim 13 is a pumping mechanism that generates an air flow from the outside to the inside of the rolling bearing, and the spaces on both sides of the bearing with the lubrication mechanism in the space between the main shaft and the housing. A spindle device for a machine tool provided with a communication passage for communicating parts.

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