JP2002372054A - Rolling bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing device with a long service life, hardly causing wear and seizure by restraining the leakage of a lubricant filled inside a rolling bearing. SOLUTION: A steam force-feeder is provided with a housing 2, a rotating shaft 1 insert-fitted to the housing 2, and angular ball bearings 4, 5 interposed between the housing 2 and the rotating shaft 1 to rotatably support the housing 2 and the rotating shaft 1. An impeller 13 for force-feeding steam by rotation is mounted to the rotating shaft 1, and an outer ring 4b provided at the angular ball bearing 4 disposed in a closest position to the impeller 13 is provided with a shoulder S1 projecting from the inner peripheral surface of the outer ring 4b, parallel with the rolling direction, at the end part closer to the impeller 13 out of both end parts. The height of the shoulder S1 is set to be high enough to hold the ball 4c even when axial load is applied thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing device, and more particularly to a rolling bearing suitably used for a steam pump or a compressor device for a fuel cell, a dental handpiece, a lathe for a machine tool, a grinding machine, and the like. Related to the device.

[0002]

2. Description of the Related Art A rolling bearing device including a housing, a shaft inserted into the housing, and a rolling bearing for supporting the housing and the shaft so as to be rotatable relative to each other is known as a fuel cell, a dental handpiece, and a machine tool. It is used for various devices such as machines. For example, a fuel cell may use a rolling bearing device such as an air supply device that pumps air to a cathode or a steam pump that pumps very high-temperature steam.

[0003] The fuel cell depends on the electrolyte used, such as a solid polymer type, a solid electrolyte type, a phosphoric acid type, a molten carbonate type,
Each type of fuel cell is classified as an alkaline type or the like, and each type of fuel cell has a cell in which both surfaces of an electrolyte plate or an electrolyte membrane are sandwiched between cathode (oxygen electrode) and anode (fuel electrode) electrodes as one cell. A plurality of cells are stacked in multiple layers via a separator to form a stack. Then, oxygen in the air is supplied to the cathode side as an oxidant gas, and hydrogen is supplied to the anode side as a fuel gas.

[0004] Such a fuel cell is provided with an air supply device for supplying air to the cathode side by pressure. The air supply device includes a turbocharger system in which a compressor is driven by an exhaust gas turbine, and a compressor in which a motor is used. There is a motor driving method for driving. Further, when supplying oxygen and hydrogen to the fuel cell for reaction, depending on the type of the fuel cell (for example, solid polymer type), it is necessary to add water vapor for the reaction. Further, for example, when gasoline is used as fuel, very high temperature steam is required. Therefore, a steam pump as shown in FIG. 8 may be required to increase the energy efficiency of the fuel cell.

[0005] The rotating shaft 101 of the compressor or the steam pump as described above is provided with lubricated rolling bearings 104 and 10.
5 rotatably supports the housing 102. As the lubrication system for the rolling bearings 104 and 105, oil lubrication or grease lubrication is adopted depending on the use of the fuel cell. For example, oil fuel lubrication is not suitable, and grease lubrication is preferable since reduction in weight and simplification of the system are required for fuel cell systems for automobiles. This is because in the case of oil lubrication, a system for supplying lubricating oil to the inside of the rolling bearing is required, which is contrary to the above requirement.

If the lubrication system of the impeller supporting rolling bearing of the compressor or the steam pump is oil lubrication, the impeller 108 and the impeller supporting rolling bearing 10
Grease lubrication is preferable because there is a problem that the lubricating oil passes through the seal portion 106 located between the lubricating oil and air and steam.

[0007]

In the above-described compressor and the steam pump of FIG. 8, the rolling bearings 104 and 105 for supporting the rotating shaft 101 have a working point distance in order to increase a load capacity against a moment load. And are usually arranged in a back-to-back combination. Therefore, the rolling bearing 1 disposed closest to the impeller 108 among the rolling bearings 104 and 105.
The outer ring 104b provided in the outer ring 104 is a counterbore outer ring, and almost the entire shoulder of an end of the outer ring 104b closer to the impeller 108 is removed.

The grease (not shown) sealed in the rolling bearing 104 moves toward the outer ring 104b by centrifugal force due to the rotation of the rotating shaft 101, and thus the outer ring 10b
4b does not have a shoulder at the end closer to the impeller 108, the grease near the outer ring 104b will
4 easily leaks to the outside. Inner ring 10 of rolling bearing 104
4a, the outer ring 104b and the rolling element 104c are rolling and sliding through the EHL oil film. However, when the grease leaks, the amount of the grease decreases, so that the EHL oil film is hardly formed. When the rotating shaft 101 to which the impeller 108 is connected rotates at high speed, heat generated by sliding friction at that time causes the EHL oil film to be further thinned. Therefore, the inner ring 104a, the outer ring 104b, and the rolling elements 104c are made of a metal material. In this case, abrasion due to metal contact is likely to occur, which may result in seizure. As a result, the life of the steam pump will be significantly reduced.

In particular, the rolling bearing 104 includes an impeller 108
, And water and foreign matter easily enter therethrough, so that the adverse effect due to insufficient grease is more likely to appear than the rolling bearing 105. In the steam pump, if the rotation and stop of the impeller 108 are repeated, the space on the back surface of the impeller 108 is repeatedly subjected to negative pressure and positive pressure. It is sucked in the direction and leaks easily. In particular, when a non-contact type seal is employed for a sealing device provided in the opening 102a of the housing 102 and for sealing between the housing 102 and the rotating shaft 101, the housing 10
Since the space between the housing 2 and the rotating shaft 101 is not completely sealed and the inside and the outside of the housing 102 are slightly communicated with each other, the above-described problem is likely to occur.

On the other hand, in a dental handpiece or a machine tool, a tool for processing or a work as a workpiece is fixed to a tip of a rotating shaft, and water or a cutting fluid is used for processing. Cutting powder, polishing powder, etc. are generated. Such foreign matter easily enters the inside of the rolling bearing arranged closest to the tool or the work. Therefore,
If the grease leaks from the rolling bearing and the absolute amount of the grease decreases, an EHL oil film is less likely to be formed between the race and the rolling element, and the foreign matter may be caught and abrasion or seizure may occur. As a result, the life of the rolling bearing device is greatly reduced.

Therefore, the present invention solves the above-mentioned problems of the prior art, and provides a long-life rolling bearing device in which the lubricant sealed in the rolling bearing hardly leaks and wear and seizure hardly occur. The task is to provide.

[0012]

In order to solve the above problems, the present invention has the following arrangement. That is, the rolling bearing device of the present invention includes a housing, a shaft inserted into the housing, and a rolling interposed between the housing and the shaft to support the housing and the shaft so as to be relatively rotatable. And a member for converting the rotation of the housing or the shaft into a predetermined work, the rolling bearing device being mounted on a rotating side of the housing or the shaft, and arranged at a position closest to the member. The outer ring provided in the provided rolling bearing is provided with a shoulder or a brim that projects from the inner peripheral surface of the outer ring and is parallel to the rolling direction at least at one end of the two ends that is closer to the member. The height of the brim is characterized in that it is high enough to hold the rolling element even when an axial load is applied.

With such a configuration, the lubricant inside the rolling bearing, which has moved to the outer ring side due to the centrifugal force of rotation, is held by the shoulder or the brim having a sufficient height. It is hard to leak out of the rolling bearing.
The rolling bearing arranged closest to the member,
Although the lubricant is likely to leak due to the influence of the rotation of the member (such as the effect of the suction force acting on the lubricant), the leakage of the lubricant can be suppressed by the shoulder or the brim. Therefore, an oil film is easily formed between the bearing ring and the rolling element,
Wear and seizure hardly occur.

Further, the rolling bearing arranged closest to the above-mentioned member is apt to allow foreign matter to enter, but it is advantageous for entry of foreign matter because the oil film is easily formed as described above. Therefore, the rolling bearing device has a long life.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a rolling bearing device according to the present invention will be described with reference to the drawings. [First Embodiment] FIG. 1 is a longitudinal sectional view showing a structure of a steam pump for a fuel cell which is a first embodiment of a rolling bearing device according to the present invention.

The rotating shaft 1 is inserted into the housing 2, and both ends of the rotating shaft 1 protrude from openings 2 a and 2 b at both ends of the housing 2. One end of the rotating shaft 1 (the left end in FIG. 1) is provided with an impeller 13 for pressure-feeding steam.
A member for converting the rotation of the rotating shaft 1 into a work of pumping water vapor is attached by a nut 14, and the impeller 13 is arranged outside the housing 2. A housing lid 10 is attached to the end of the housing 2 opposite to the side where the impeller 13 is located (the right end in FIG. 1), and the opening 2b is 10 is formed.

The rotating shaft 1 is rotatably supported by the housing 2 by two angular ball bearings 4 and 5 interposed between the rotating shaft 1 and the housing 2. These angular ball bearings 4, 5 are fitted on the outer peripheral surface of the rotating shaft 1 and the inner peripheral surface of the housing 2, and the respective inner rings 4 a,
5a is fixed to the rotating shaft 1, and the respective outer races 4b, 5b
Are fixed to the housing 2.

Between the two angular ball bearings 4 and 5,
An inner race spacer 11 fitted to the outer peripheral surface of the rotating shaft 1 and an outer race spacer 12 fitted to the inner peripheral surface of the housing 2 are interposed. The inner race spacer 11 contacts the inner races 4a and 5a, Outer ring spacer 1
Reference numeral 2 is in contact with the outer rings 4b and 5b. The two angular ball bearings 4 and 5 are spaced apart in the axial direction (operating point distance) so as to withstand the moment load acting during use.
It is arranged on the rotating shaft 1. The preload loading directions of the angular contact ball bearings 4 and 5 are set in frontal combination, and a fixed position preload is loaded by the housing lid 10.

Each of the openings 2a and 2b is provided with a sealing device to seal between the rotating shaft 1 and the housing 2. The labyrinth seal 6 is provided in the opening 2a on the side where the impeller 13 is mounted, and the mechanical seal 7 is provided in the opening 2b on the side opposite to the side where the impeller 13 is mounted. Since the labyrinth seal 6 is a non-contact type sealing device, the space between the rotating shaft 1 and the housing 2 is not completely sealed and has a slight gap. Therefore, the inside and the outside of the housing 2 communicate with each other. On the other hand, since the mechanical seal 7 is a contact-type sealing device, the rotating shaft 1 and the housing 2
Is completely sealed, and the inside and the outside of the housing 2 are not communicated with each other.

Here, the angular ball bearing 4 will be described in detail with reference to FIGS. 1 and 2 (a partial cross-sectional view showing the angular ball bearing 4 in FIG. 1 in an enlarged manner). Among the two angular ball bearings 4 and 5, the angular ball bearing 4 disposed closest to the impeller 13 is a counter bore ball bearing. That is, this angular contact ball bearing 4
A shoulder S1 protruding from the inner peripheral surface of the outer ring 4b and parallel to the rolling direction is provided at an end of the both ends of the outer ring 4b closer to the impeller 13, and a shoulder S2 at an end farther from the impeller 13 is provided. Most have been removed. The height of the shoulder S1 is sufficient to hold the ball 4c in the angular ball bearing 4 even when an axial load is applied when the bearing is used.

The inner ring 4 of the angular contact ball bearings 4 and 5
a, 5a and outer rings 4b, 5b are made of stainless steel (SUS4
40C), and the balls 4c and 5c are made of ceramic (Si).
₃ N ₄ ). Thus, the inner rings 4a, 5a
Since the outer rings 4b and 5b are made of stainless steel, the bearings 4 and 5 have excellent corrosion resistance. Both bearings 4 and 5 have outer ring guide type polyimide resin retainers 4d and 5d, respectively, and are grease lubricated.

In such a water vapor pump, the impeller 13 is rotated by rotating the rotating shaft 1 by an electric motor (not shown) attached to the rotating shaft 1 via a contact type coupling (not shown), so that the steam is pumped. It is supposed to be. Since the pressure inside the housing 2 becomes a negative pressure during rotation and a positive pressure during a stop, if the rotation and the stop are repeated, the pressure inside the housing 2 will be a negative pressure and a positive pressure.

The labyrinth seal 6 is provided in the opening 2a on the side where the impeller 13 is mounted in order to prevent invasion of water vapor.
However, since the non-contact type sealing device is used to prevent heat generation due to friction, when the pressure inside the housing 2 changes from positive pressure to negative pressure, grease in the angular ball bearing 4 close to the impeller 13 is provided. (Grease moved to the outer ring 4b side by the centrifugal force of rotation) exerts a suction force in the direction of the impeller 13.

At this time, in the case of the conventional steam pump as shown in FIG. 8, since the outer ring 104b does not have a shoulder at the end closer to the impeller 108, the grease must be held inside the rolling bearing 104. Grease leaks out of the rolling bearing 104 due to the suction force. As a result, abrasion occurs early and seizure easily occurs.

However, in the case of the steam pump of the present embodiment, the outer race 4b has the shoulder S1 at the end closer to the impeller, and the height of the shoulder S1 can be increased even when an axial load is applied. 4c is set high enough to hold the inside of the angular contact ball bearing 4. Since this height is high enough to hold the grease in the bearing, the grease is held inside the angular contact ball bearing 4 by the shoulder S1, and is less likely to leak out of the angular contact bearing 4 due to the suction force. . Therefore, an oil film is easily formed between the inner ring 4a, the outer ring 4b and the ball 4c, so that abrasion and seizure hardly occur, the angular ball bearing 4 has a long life, and the steam pumping machine has a long life.

On the other hand, when the pressure inside the housing 2 changes from negative pressure to positive pressure, water vapor near the impeller 13 enters the inside of the housing 2 and further enters the inside of the angular ball bearing 4 near the impeller 108. However, since an oil film is easily formed as described above, it is also advantageous against invasion of water vapor. As described above, among the two angular ball bearings 4 and 5, the angular ball bearing 4 disposed closest to the impeller 13 is in an environment in which grease easily leaks and foreign matter easily intrudes, but the shoulder S1. Grease makes it difficult for grease to leak out.
Has a long life.

The outer ring 5b of the angular contact ball bearing 5 disposed farthest from the impeller 13 is also similar to the angular contact ball bearing 4, even if an axial load is applied when the bearing is used. It is preferable to provide a shoulder high enough to hold it in 5. In that case, opposite to the angular ball bearing 4, the shoulder is provided at the end of the angular ball bearing 5 that is farthest from the impeller 13. This is preferable because the grease is held in the space between the two angular ball bearings 4 and 5, and is prevented from leaking out of the space.

In this embodiment, an electric motor is used to drive the water vapor pump and a contact-type sealing device is used for the opening 2b on the electric motor side. However, a non-contact type sealing device is used for the opening 2b. When a sealing device is used, there is a possibility that grease may leak out. Therefore, of the two ends of the angular ball bearing 5 arranged closest to the opening 2b, the shoulder is provided at the end closer to the opening 2b. Is preferably provided.

In the case where the water vapor containing hydrogen is fed under pressure, if there is a risk of fuel cell efficiency drop or explosion, etc., a magnetic coupling is adopted as the coupling to completely seal the rolling bearing device. Then, intrusion of the atmosphere may be prevented. [Second Embodiment] FIG. 3 is a longitudinal sectional view showing a structure of a steam pump for a fuel cell as a second embodiment of the rolling bearing device according to the present invention, and FIG. 4 is an angular ball bearing of FIG. FIG. 4 is an enlarged partial sectional view of FIG. 3 and 4, the same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG.

In the second embodiment, the angular ball bearing 4 disposed closest to the impeller 13 is not a counterbore ball bearing, and an axial load is applied to both ends of the outer ring 4b when the bearing is used. Shoulders S1, S high enough to hold ball 4c in angular contact ball bearing 4.
2 are provided (see FIG. 4). The preload loading directions of the angular contact ball bearings 4 and 5 are set in a back-to-back combination.

Such an angular contact ball bearing 4 has the same manufacturing cost and difficulty of assembling as the ordinary angular contact ball bearing. Further, since two angular ball bearings are back-to-back as in the prior art shown in FIG. 8, the distance between action points can be increased and the load capacity against moment load is excellent. In the fuel cell steam pump according to the second embodiment, the outer ring 4b of the angular ball bearing 4 disposed closest to the impeller 13 has shoulders S1 and S2 of sufficient height at both ends as described above. The grease that has moved to the vicinity of the outer ring 4b due to the centrifugal force of rotation causes the shoulders S1, S2
Therefore, the grease can be prevented from leaking out of the angular ball bearing 4 as much as possible.

The other structure and operation are the same as those of the first embodiment shown in FIG. [Third Embodiment] FIG. 5 is a longitudinal sectional view showing the structure of a fuel cell steam pump as a third embodiment of the rolling bearing device according to the present invention. In FIG. 5, the same or corresponding parts as in FIG. 1 are denoted by the same reference numerals as in FIG.

In the third embodiment, two bearings 4
The bearing 4 disposed closest to the impeller 13 is a four-point contact ball bearing. During the operation of the fuel cell steam pump, an axial load is applied from the non-impeller side to the impeller side. Therefore, in order to minimize the backlash of the impeller 13, the preload is applied so that the rear combination is performed when the impeller 13 is stopped and the parallel combination is used when the operation is performed.

As described above, since the bearing 4 disposed closest to the impeller 13 is a four-point contact ball bearing, the ball 4c can be held in the bearing 4 even if an axial load is applied when the bearing is used. Shoulders S1 and S2 having sufficient height are
It is provided at both ends of the outer ring 4b. Therefore, the grease that has moved to the vicinity of the outer ring 4b due to the centrifugal force of rotation is applied to both shoulders S1, S
Since the grease is held in the bearing 4 by the 2, it is possible to prevent the grease from leaking out of the bearing 4 as much as possible.

In the third embodiment, by using a four-point contact ball bearing, the preload direction is set to the rear combination when stopped, and the parallel combination when operated. However, the internal clearance of the four-point contact ball bearing and the angular ball bearing 5 disposed farthest from the impeller 13
By adjusting the amount of preload, the rear surface may be combined during operation. Then, since the action point distance on the rotating shaft 1 is increased, the load capacity for a moment load can be improved. In this case, the preload amount and the preload form may be adjusted by changing the length of the inner race spacer 11 or the outer race spacer 12.

Of course, a four-point contact ball bearing may be used so as to be in frontal combination at the time of stop and operation, and the form of preload is not particularly limited. Further, a deep groove ball bearing or the like may be used instead of the four-point contact ball bearing, and the bearing type is not particularly limited. The other configuration and operation are the same as those of the first embodiment shown in FIG.

Fourth Embodiment FIG. 6 is a longitudinal sectional view showing the structure of a dental handpiece which is a fourth embodiment of the rolling bearing device according to the present invention. In FIG. 6,
The same or corresponding parts as those in FIG. 1 are denoted by the same reference numerals as those in FIG. The rotating shaft 1 is inserted into a cylindrical housing 2 having one end closed, and an end of the rotating shaft 1 protrudes from an opening 2 a of the housing 2. The rotating shaft 1 is rotatably supported by the housing 2 by two small-diameter ball bearings 4 and 5 interposed between the rotating shaft 1 and the housing 2. The small-diameter ball bearings 4 and 5 are fitted on the outer peripheral surface of the rotating shaft 1 and the inner peripheral surface of the housing 2 to form respective inner rings 4a and 5a.
Are fixed to the rotating shaft 1, and the respective outer rings 4 b, 5 b are fixed to the housing 2.

The two small-diameter ball bearings 4 and 5 have inner rings 4a and 5
a, outer rings 4b and 5b, and balls 4c and 5c are made of stainless steel (SUS440C). Therefore, the two bearings 4 and 5 have excellent corrosion resistance. A turbine blade 20 is attached to the center of the rotating shaft 1 so as to be sandwiched between small-diameter ball bearings 4 and 5. Further, between the turbine blade 20 and the two small-diameter ball bearings 4 and 5, inner race spacers 11 and 11 fitted to the outer peripheral surface of the rotating shaft 1 are interposed, and the inner races 4a and 5a are respectively provided. At the end of the rotating shaft 1 protruding from the opening 2a of the housing 2 which is in contact with the housing 2, a tool 21 for machining teeth (a member for converting the rotation of the rotating shaft 1 into the work of machining teeth) is provided by a nut 22 Installed. In addition, a labyrinth seal 6 is provided in the opening 2 a to seal the space between the rotating shaft 1 and the housing 2. Since the labyrinth seal 6 is a non-contact type sealing device, the space between the rotating shaft 1 and the housing 2 is not completely sealed and has a slight gap. Therefore, the housing 2
The inside and outside communicate with each other.

Although the small-diameter ball bearings 4 and 5 are grease lubricated, the harm is extremely small in consideration of the effect on the human body. For example, the flow of poly-α-olefin (PAO), ISO standard VG32, VG68, etc. It is desirable to use grease using paraffin or the like as a base oil. Further, the small-diameter ball bearings 4 and 5 include shield plates 4e and 5e. Further, a constant-pressure preload is applied to both bearings 4 and 5 by the nut 15 and the preload spring 26 so as to form a front combination, and the axial load acting from the tool 21 side during machining is supported by the small-diameter ball bearings 4 and 5. It is supposed to. Further, the outer ring 4b, which is a fixed ring, is supported by the O-ring 23, so that the small-diameter ball bearing 4 is prevented from vibrating due to imbalance or external force.

In such a dental handpiece, the rotary shaft 1 is rotated by introducing air from a driving air inlet 24 provided in the housing 2 and blowing the air on the turbine blade 20. The drive system of the rotating shaft 1 is not limited to such an air turbine system, but may be a system driven by an electric motor connected by a coupling mechanism such as a coupling.

When the rotating shaft 1 rotates, the grease in the small-diameter ball bearing 4 moves to the vicinity of the outer ring 4b due to centrifugal force, and grease easily leaks from inside the small-diameter ball bearing 4. However, the outer ring 4b of the small-diameter ball bearing 4 disposed at the position closest to the tool 21 among the two small-diameter ball bearings 4 and 5 has a shoulder S1 at the end of the two ends that is closer to the tool 21. The height of the shoulder S1 is sufficient to hold the ball 4c in the small-diameter ball bearing 4 even when an axial load is applied. Since this height is high enough to hold the grease in the bearing, the grease is held inside the small-diameter ball bearing 4 by the shoulder S1, and is hard to leak out. Therefore,
Since an oil film is easily formed between the inner ring 4a, the outer ring 4b, and the ball 4c, wear and seizure hardly occur, the small-diameter ball bearing 4 has a long life, and the dental handpiece has a long life.

When the tool 21 is rotated to process the teeth, water is used, and cutting powder, abrasive powder and the like are generated. The opening 2a is provided with a labyrinth seal 6 for preventing water and foreign matter from entering. However, since it is a non-contact type sealing device for preventing heat generation due to friction, water and foreign matter (cutting powder, abrasive powder) are prevented. There is a risk of passing through the labyrinth seal 6 and entering the housing 2 and further into the small-diameter ball bearing 4. Then, an oil film may not be easily formed between the inner and outer rings 4a, 4b and the ball 4c, or there is a possibility that foreign matter may be caught. However, as described above, the grease is held inside the small-diameter ball bearing 4 to form an oil film. Because it is easy, it is advantageous against invasion of water and foreign matter.

As described above, the small-diameter ball bearing 4 disposed closest to the tool 21 among the two small-diameter ball bearings 4 and 5 is in an environment in which grease easily leaks and foreign matters easily enter. Since the grease is less likely to leak due to the shoulder S1, the small-diameter ball bearing 4 has a longer life. [Fifth Embodiment] FIG. 7 is a longitudinal sectional view showing the structure of a machine tool spindle which is a fifth embodiment of the rolling bearing device according to the present invention. In FIG. 7, the same or corresponding parts as in FIG. 1 are denoted by the same reference numerals as in FIG.

The rotary shaft 1 is inserted into the housing 2, and both ends of the rotary shaft 1 project from openings 2 a and 2 b at both ends of the housing 2. Housing lids 10, 10 are attached to both ends of the housing 2, and the opening 2
a, 2b are formed on the housing lids 10, 10.
And, 4 which is interposed between the rotating shaft 1 and the housing 2
The rotating shaft 1 is rotatably supported by the housing 2 by the angular contact ball bearings 4, 4, 4, 4 and one cylindrical roller bearing 5. The angular ball bearings 4, 4, 4, and 4 and the cylindrical roller bearing 5 are fitted on the outer peripheral surface of the rotating shaft 1 and the inner peripheral surface of the housing 2 to form respective inner rings 4 a, 4 a, 4.
a, 4a, 5a are fixed to the rotating shaft 1, and the respective outer races 4b, 4b, 4b, 4b, 5b are fixed to the housing 2.

Between the four angular ball bearings 4, 4, 4, 4, three inner ring spacers 11, 11, 11 fitted on the outer peripheral surface of the rotating shaft 1 and the inner peripheral surface of the housing 2 are provided. Three fitted outer ring spacers 12, 12, 12 are interposed, the inner ring spacer 11 is in contact with the inner ring 4a, and the outer ring spacer 12 is connected to the outer ring 4b.
Is in contact with And four angular contact ball bearings 4,
4,4,4 are a front combination and are preloaded.

The four angular ball bearings 4, 4, 4, 4 and the cylindrical roller bearing 5 have inner rings 4 a, 5 a and outer rings 4 b, 5.
b, balls 4c and 5c are both stainless steel (SUS440
C). Therefore, the bearings 4 and 5 have excellent corrosion resistance. All bearings 4 and 5 have cages 4d and 5d made of polyimide resin of an outer ring guide type, and are grease-lubricated.

At the front end (left end in FIG. 1) of the rotary shaft 1, a processing tool or a work (not shown) (a member for converting the rotation of the rotary shaft 1 into a work called processing) is attached. . Further, a sealing device is provided in each of the openings 2a and 2b to seal the space between the rotating shaft 1 and the housing 2. Each of the sealing devices is a labyrinth seal 6 which is a non-contact type sealing device. Therefore, the space between the rotating shaft 1 and the housing 2 is not completely sealed but has a slight gap, and the inside and the outside of the housing 2 communicate with each other.

When the rotating shaft 1 is rotated at the time of machining, the grease in the angular contact ball bearing 4 is displaced by centrifugal force.
The grease easily moves to the vicinity and leaks from the inside of the angular contact ball bearing 4. However, the outer ring 4b of the angular ball bearing 4 (the leftmost angular ball bearing 4 in FIG. 7) disposed at the position closest to the tool or the work among the four angular ball bearings 4, 4, 4, 4. A shoulder S1 is provided at an end of the both ends which is closer to the tool or the work, and the height of the shoulder S1 is such that the ball 4c is held in the angular ball bearing 4 even when an axial load is applied. It is high enough.

Since this height is high enough to hold the grease in the bearing, the grease is held in the inside of the angular ball bearing 4 by the shoulder S1, and hardly leaks out. Therefore, since an oil film is easily formed between the inner ring 4a, the outer ring 4b and the ball 4c, wear and seizure hardly occur, the angular ball bearing 4 has a long life, and the spindle for the machine tool has a long life.

When a workpiece is machined by using such a spindle for a machine tool as a lathe or a grinder for a machine tool, a cutting fluid is used, and cutting powder and grinding powder of the workpiece are generated. The opening 2a is provided with a labyrinth seal 6 to prevent cutting fluid or foreign matter from entering, but since it is a non-contact type sealing device to prevent heat generation due to friction, cutting fluid or foreign matter (cutting powder, abrasive powder) is used. ) May pass through the labyrinth seal 6 and enter the housing 2 and further into the forefront angular ball bearing 4. Then, an oil film may not be easily formed between the inner and outer rings 4a, 4b and the ball 4c, or there is a possibility that foreign matter may be caught. Is easily formed, which is advantageous against invasion of cutting fluid and foreign matter.

As described above, among the four angular ball bearings 4, 4, 4, and 4, the angular ball bearing 4 disposed at the position closest to the tool or the work easily leaks grease and foreign matter enters. Although the environment is easy to perform, the grease hardly leaks due to the shoulder S1, so that the angular ball bearing 4 has a long life. The outer ring 4b of the angular ball bearing 4 (the leftmost angular ball bearing 4 in FIG. 7) disposed at the farthest position from the tool or the work among the four angular ball bearings 4, 4, 4, 4. ,
As with the above-described angular ball bearing 4 disposed closest to the tool or workpiece, the ball 4c has a height sufficient to hold the ball 4c in the angular ball bearing 4 even when an axial load is applied when the bearing is used. Preferably, a shoulder is provided. In this case, the shoulder is provided at an end remote from the tool or the work, as opposed to the angular ball bearing 4 closer to the tool or the work. This is preferable because the grease is held in the space between the two angular ball bearings 4 and 4 and is prevented from leaking out of the space.

Although the outer ring spacer 12 is interposed between the angular ball bearings 4, the leaked grease is held in the space between the angular ball bearing 4 and the outer ring spacer 12, so that the leakage is prevented. Sprayed grease is prevented from scattering. The first to fifth embodiments described above are examples of the present invention, and the present invention is not limited to the above embodiments.

For example, in each embodiment, a steam pump, a dental handpiece, and a spindle for a machine tool have been described as examples of the rolling bearing device. However, the present invention is applicable to various other rolling bearing devices. Can be applied. Further, in each of the embodiments, the rolling bearing device in which the shaft rotates is described. However, it is needless to say that the present invention is applicable to a rolling bearing device in which the housing rotates.

Further, the type of the rolling bearing provided in the rolling bearing device of the present invention is not particularly limited. For example, radial rolling bearings such as deep groove ball bearings, angular ball bearings, four-point contact ball bearings, cylindrical roller bearings, and needle roller bearings. However, when the rolling bearing is a roller bearing, a brim instead of a shoulder is provided. When a plurality of rolling bearings are provided, one or two or more rolling bearings may be used. When two or more types of rolling bearings are provided, the combination of the types is not particularly limited.
The number of rolling bearings that support the shaft is not particularly limited, and may be one or two or more.

Further, in order to prevent the lubricant of the rolling bearing provided in the rolling bearing device from leaking out of the rolling bearing device, openings 2a, 2b,
In particular, an opening 2 on the side where a member for converting the rotation of the rotating shaft 1 into a predetermined work, such as an impeller or a tool, is attached.
In a, a sealing device is provided as in each embodiment. For example, in the first embodiment, since it is not desirable for the lubricant to be mixed into the water vapor, a sealing device is provided at the opening 2a. However, the type and type of the sealing device are not particularly limited, and the sealing device may not be provided.

Further, in order to prevent the lubricant of the rolling bearing from leaking out of the rolling bearing, the rolling bearing may be provided with a sealing device such as a seal or a shield plate. As a type of the sealing device, a contact type is preferable in order to enhance the sealing property, but a non-contact type may be used in order to avoid heat generation due to contact with the sealing device. Furthermore, the method of lubricating the rolling bearing is not particularly limited,
For example, in a fuel cell system mounted on an automobile as in the first embodiment, grease lubrication is preferable because weight reduction and simplification of the system are required. Further, if oil lubrication is used, lubricating oil may be mixed into the compressed air or steam from the labyrinth seal 6. For example, in the case of a steam pumping machine as in the first embodiment or a dental handpiece as in the second embodiment, Grease lubrication is desirable for equipment that requires minimum mixing of the lubricant component into the pressure-feeding medium. Oil lubricant lubrication, lubrication lubrication, or forced lubrication may be used when the lubricant is allowed to be mixed into the pumping medium or when lubrication may be insufficient with grease lubrication.

Further, the type of grease for lubricating the rolling bearing is not particularly limited. However, when water is expected to enter as in the first embodiment, for example, the thickener is made of diurea. The oil is poly-α-olefin oil (PA
O) or grease in which the thickener is lithium soap and the base oil is mineral oil to which a rust inhibitor has been added is preferable.

Further, when there is a high possibility of contact with steam or water as in the first and second embodiments, the race of the rolling bearing is made of SUS44 to improve rust resistance.
0C, but usually, stainless steel,
It may be made of any material such as bearing steel such as SUJ2, heat-resistant steel such as M50 (when heat resistance and wear resistance are required), carburized steel, and ceramic materials. Further, the track surface of the rolling bearing disposed closest to the housing or the member that converts the rotation of the shaft into a predetermined work is subjected to a surface treatment by nitriding treatment, ceramic film spraying, DLC (diamond-like carbon), or the like. It is very preferable to improve the abrasion resistance by using the method.

Further, the material of the cage provided in the rolling bearing is not particularly limited, and brass, iron and the like can be used in addition to the polyimide resin. Regarding the guide type of the cage, any of the outer ring guide, the inner ring guide, and the ball guide may be used without any problem. Furthermore, the operating conditions of the rolling bearing device of the present invention, such as the operating rotational speed, the applied load, and the ambient temperature, are not particularly limited.

Furthermore, when a ball bearing is used as the rolling bearing provided in the rolling bearing device, it is possible to accurately position the bearing in the axial direction by applying a preload, suppress the shaft runout, and suppress the ball from slipping. it can. As a method of applying a preload, a fixed position preload method is suitable for applications requiring rigidity, and a constant pressure preload method using a spring or the like is suitable for applications requiring high speed.

[0061]

As described above, in the rolling bearing device of the present invention, since the lubricant inside the rolling bearing is held by the shoulder or the brim, it is difficult for the lubricant to leak out of the rolling bearing. Therefore, an oil film is easily formed between the bearing ring and the rolling element,
Wear and seizure hardly occur and long life.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing the structure of a fuel cell steam pump as a first embodiment of a rolling bearing device according to the present invention.

FIG. 2 is a partial cross-sectional view of an angular contact ball bearing provided in the fuel cell steam pump of FIG. 1;

FIG. 3 is a longitudinal sectional view showing a structure of a fuel cell steam pump as a second embodiment of the rolling bearing device according to the present invention.

FIG. 4 is a partial cross-sectional view of an angular contact ball bearing provided in the fuel cell steam pump of FIG. 3;

FIG. 5 is a longitudinal sectional view showing the structure of a fuel cell steam pump as a third embodiment of the rolling bearing device according to the present invention.

FIG. 6 is a longitudinal sectional view showing a structure of a dental handpiece which is a fourth embodiment of the rolling bearing device according to the present invention.

FIG. 7 is a longitudinal sectional view showing the structure of a machine tool spindle which is a fifth embodiment of the rolling bearing device according to the present invention.

FIG. 8 is a longitudinal sectional view showing the structure of a conventional fuel cell steam pump.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary shaft 2 Housing 4 Rolling bearing 4b Outer ring 4c Ball (rolling element) 13 Impeller 21 Tool S1 Shoulder

Claims (1)

[Claims] 1. A housing, a shaft inserted into the housing, and a rolling bearing interposed between the housing and the shaft to rotatably support the housing and the shaft. In addition, in a rolling bearing device in which a member that converts rotation of the housing or the shaft into a predetermined work is attached to a rotating side of the housing or the shaft, a rolling bearing disposed closest to the member The outer ring provided with, at least at the end of the both ends thereof that is closer to the member, is provided with a shoulder or collar that projects from the inner peripheral surface of the outer ring and is parallel to the rolling direction, and the height of the shoulder or collar is A rolling bearing device having a height sufficient to hold a rolling element even when an axial load is applied.