JP2011185326A - Sealing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing device maintaining a stable sealing function even in a low-temperature environment. <P>SOLUTION: This sealing device 20 includes a sealing member 26 provided with sliding contact portions made to slidably contact with the sealing surface 29 of rolling bearing rings, and seals a bearing space between a pair of bearing rings. In the sealing member 26, heating wires 30a, 30b generating heat by supply of current are arranged along a circumferential direction, and heat at least sliding contact portions 32a, 32b. The sealing member 26 is provided with a garter spring 27 pressing the sliding contact portions to the sealing surface, and the garter spring 27 may be used as the heating wire. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sealing device, and more particularly to a sealing device used for a railway vehicle axle bearing.

  As a railway vehicle axle bearing, a grease-lubricated bearing sealing device having a structure shown in FIG. 8 is known (Patent Document 1). FIG. 8 shows a sealing device 111 on the rear lid 110 side of the bearing 100, and a shield 104 constituting a labyrinth seal and an oil seal 106 for contact sealing are attached to a seal case 103 provided on the bearing outer ring 101. ing. The oil seal 106 includes a metal ring 113, a rubber seal body 107 baked on the metal ring 113, and an annular garter spring 109. The seal body 107 has a first lip 107a and a second lip 107b, and a garter spring 109 is mounted on the outer peripheral surface of the first lip 107a. The first lip 107a and the second lip 107b are in sliding contact with the seal surface 113, so that the first lip 107a prevents grease leakage and the second lip 107b has a dustproof and waterproof effect. The tip of the seal case 103 is loosely fitted in an annular groove 112 provided in the rear lid 110 to constitute a labyrinth seal. An oil drain (not shown) is provided on the opposite side of the bearing 100, but a similar sealing device is used between the oil drain and the bearing 100.

JP 2002-139054 A

  Large-sized bearings used in the railway vehicles and the like exemplified above may be used in a cold region at an extremely low temperature of, for example, −40 ° C. Under such an environment, due to an event such as condensation or freezing, the seal body 107 becomes hard and the elastic force is lowered, and there is a possibility that some or all of the lip portions 107a and 107b are peeled off at the time of activation. As a result, there is a possibility that a sufficient sealing function cannot be performed. For this reason, conventionally, in order to avoid the freezing of the seal body 107, the vehicle itself is stored in the garage at night to avoid a decrease in the ambient temperature. However, this is not a sufficient measure. It was.

  In view of the above problems, an object of the present invention is to provide a sealing device that can maintain a stable sealing function even in a low temperature environment.

  The sealing device of the present invention includes a sealing member having a sliding contact portion that is in sliding contact with a seal surface of a bearing ring of a rolling bearing, and the sealing member that seals a bearing space between a pair of bearing rings, A heating wire that generates heat by the supply is provided along the circumferential direction, and at least the sliding contact portion is heated by supplying a current to the heating wire.

  According to the sealing device of the present invention, heat is generated when current is supplied to the heating wire, and at least the sliding contact portion can be heated by this heat. Thereby, since the freezing of the sliding contact portion can be avoided even in a low temperature environment, the elastic force can be maintained, and part or all of the sliding contact portion can be prevented from peeling off at the time of activation.

  The seal member may include a garter spring that presses the sliding contact portion against the seal surface, and the garter spring may be the heating wire. Thereby, current can be supplied to the garter spring to cause the garter spring itself to generate heat, and the sliding contact portion can be heated. For this reason, it is not necessary to separately provide a heating wire.

  The sealing member includes a plurality of sliding contact portions, and the heating wire can be provided between adjacent sliding contact portions in the sealing member. Thereby, the temperature of a plurality of sliding contact parts can be raised with one heating wire.

  The heating wire may have a shape meandering on the circumference of the seal member. Thereby, the sealing performance of the sliding contact portion can be maintained.

  The heating wire is preferably composed of a nickel chromium alloy or an iron chromium alloy. By causing a current to flow using these materials having good electrothermal properties, the temperature of the sealing member can be increased efficiently.

  Another sealing device of the present invention includes a sealing member having a sliding contact portion that is in sliding contact with a seal surface of a bearing ring of a rolling bearing, and the sealing member that seals a bearing space between a pair of bearing rings, And an elastic body mixed with a conductive material that generates an electrothermal effect, and at least the sliding contact portion is heated by supplying a current to the elastic body.

  According to another sealing device of the present invention, heat is generated when current is supplied to the elastic body, and at least the sliding contact portion can be heated by this heat. Thereby, since the freezing of the sliding contact portion can be avoided even in a low temperature environment, the elastic force can be maintained, and part or all of the sliding contact portion can be prevented from being peeled off at startup. In addition, since the seal member itself can be heated by supplying current to the elastic body, it is not necessary to separately provide a heating wire.

  A temperature sensor can be provided in the seal member or in the vicinity of the seal member. In this case, it is possible to provide control means for controlling the supply amount of the supplied current in accordance with the temperature detected by the temperature sensor. Thereby, the sealing member can be controlled to an optimum temperature. Further, current can be supplied only when necessary (when the seal member may freeze), and power consumption can be saved.

  A rolling bearing according to the present invention is a rolling bearing including an inner ring, an outer ring, a rolling element interposed between the inner ring and the outer ring, and a cage that holds the rolling element at a predetermined circumferential interval. The sealing device of the present invention is provided. In particular, it is desirable to apply the sealing device of the present invention to a railway vehicle axle bearing.

  As described above, according to the sealing device and the rolling bearing of the present invention, a stable sealing function can be maintained even in a low temperature environment.

It is principal part sectional drawing of the sealing device which shows 1st Embodiment of this invention. It is sectional drawing of the bearing provided with the sealing device which shows 1st Embodiment of this invention. It is a principal part enlarged front view of the sealing device which shows 1st Embodiment of this invention. It is principal part sectional drawing of the sealing device which shows 2nd Embodiment of this invention. It is a principal part expanded sectional view of the sealing device which shows 3rd Embodiment of this invention. It is a principal part enlarged front view of the sealing device which shows the modification of this invention. It is a principal part expanded sectional view of the sealing device which shows 4th Embodiment of this invention. It is a principal part expanded sectional view of the bearing provided with the conventional sealing device.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. In this embodiment, a case where the sealing device is applied to a railway vehicle axle bearing will be described.

  The railcar axle bearing shown in FIG. 2 includes a rolling bearing 10 (in the present embodiment, a tapered roller bearing) disposed at the end 1 a of the axle 1. The tapered roller bearing 10 includes an outer ring 2, a pair of inner rings 4, and a plurality of rolling elements 6 as main components. The outer ring 2 is a double-row outer ring in which two rows of tracks are formed on the inner periphery. Each inner ring 4 has a track formed on the outer periphery. Two rows of rolling elements 6 (in the embodiment, tapered rollers) are interposed between the race of the outer ring 2 and the race of the inner ring 4 so as to roll freely. The tapered rollers 6 in each row are held at a predetermined interval in the circumferential direction by a cage 8.

  The outer ring 2 is fixed to a shaft box (not shown), and the shaft box is fixed to a frame or the like. The inner ring 4 is sandwiched between a front lid 12 located on the shaft end side (left side in FIG. 2) and a rear lid 16 located on the opposite shaft end side (right side in FIG. 2). An inner ring spacer 5 is interposed between the pair of inner rings 4. An oil drain 14 is interposed between the front lid 12 and the inner ring 4. The front lid 12 is fixed to the shaft end of the axle 1 with bolts 18. The rear lid 16 is in contact with the inner ring 4 on the one hand and the step 1b of the axle 1 on the other hand. The pair of inner rings 4, the inner ring spacer 5, the oil drain 14 and the rear cover 16 constitute one raceway ring 9 a, and the outer ring 2 constitutes the other raceway ring 9 b.

  The sealing device 20 according to the first embodiment of the present invention is disposed at both ends of the outer ring 2. As shown in FIG. 1, the sealing device 20 includes a seal case 22 provided on the outer ring 2, a shield 23 attached to the seal case 22, and an oil seal 24 for contact sealing.

  The seal case 22 has a stepped cylindrical shape, and in the illustrated embodiment, includes a large diameter portion 22a, a medium diameter portion 22b, and a small diameter portion 22c. The large diameter portion 22a is fixed by, for example, press-fitting into the inner peripheral surface of the end portion of the outer ring 2. A shield 23 is attached to the middle diameter portion 22b of the seal case 22 to constitute a labyrinth seal. This shield 23 blocks the grease inside the bearing and prevents the grease from pushing toward the oil seal 24 side.

  The oil seal 24 is a contact seal that is in sliding contact with the seal surface 29 of the rear lid 16, and is inserted into the middle diameter portion 22 b of the seal case 22. Oil seals 24 having various structures are known, and can be appropriately selected from these and employed. The oil seal 24 illustrated in FIG. 1 includes a metal ring 25 and a seal member 26, and is positioned by placing the metal ring 25 against a shoulder that rises in a radial direction from the small diameter portion 22c of the seal case 22. .

  The seal member 26 includes a rubber seal body 28 baked on the metal ring 25 and a garter spring 27. The seal body 28 includes a first slidable contact portion (first seal lip) 32a having a garter spring 27 mounted on the outer periphery, and a second slidable contact portion (second seal lip) 32b positioned outside the first seal lip 32a. The first seal lip 32 a and the second seal lip 32 b are in sliding contact with the seal surface 29 of the rear lid 16.

  On the seal surface side of the first seal lip 32a and the second seal lip 32b of the seal body 28, heating wires 30a and 30b are arranged along the circumferential direction, respectively. The heating wires 30a and 30b are preferably made of a material having good heat resistance, such as a nickel chromium alloy or an iron chromium alloy, and when the seal body 28 is manufactured by vulcanization molding, the seal lip 32a is formed. , 32b are pre-molded in advance.

  As shown in FIG. 3, both ends of the heating wires 30a and 30b are exposed from a portion that does not affect the sealing performance, and both ends are connected to a power source 31 serving as a current supply source. The power supply 31 automatically or manually supplies current to the heating wires 30a and 30b, or stops supplying current.

  When the power supply 31 is turned on, current is supplied to the heating wires 30a and 30b. Thereby, the heating wires 30a and 30b generate heat, and at least the first seal lip 32a and the second seal lip 32b can be heated by this heat. Thereby, freezing of the first seal lip 32a and the second seal lip 32b can be avoided even in a low temperature environment, and the elastic force can be maintained. Accordingly, it is possible to prevent part or all of the first seal lip 32a and the second seal lip 32b from peeling off at the time of activation.

  Thus, the sealing device of the first embodiment of the present invention can maintain a stable sealing function even in a low temperature environment. Further, the heating wire 30 is made of a nickel chromium alloy or an iron chromium alloy, and the first seal lip 32a and the second seal lip 32b are made to flow by using a material having good heat resistance. The temperature can be increased efficiently.

  FIG. 4 shows a sealing device according to a second embodiment of the present invention. In this case, a temperature sensor 35 that detects the temperature of the seal body 28 is provided on the seal body 28 of the seal member 26. The temperature sensor 35 is connected to the control means 36. This control means 36 is comprised, for example with a microcomputer, and controls the supply amount of the electric current supplied to the heating wires 30a and 30b according to the detected temperature detected by the temperature sensor 35. For example, when a reference temperature range that normally functions as the oil seal 24 is preset in the control means 36 and the temperature sensor 35 detects a temperature lower than the reference temperature range, the control means 36 increases the amount of current supplied. Control is performed. Further, when the temperature sensor 35 detects a temperature higher than the reference temperature range, the control unit 36 performs control so as to decrease the current supply amount or stop the current supply.

  Thus, since the sealing device of the second embodiment includes the temperature sensor 35 and the control means 36, the seal member 26 can be controlled to an optimum temperature. In addition, the current can be supplied to the heating wire 30 only when necessary (when the seal main body 28 is likely to freeze), and power consumption can be saved. In the sealing device shown in FIG. 4, the same components as those of the sealing device shown in FIGS. 1 to 3 are denoted by the same reference numerals as those in FIGS.

  FIG. 5 shows a sealing device according to a third embodiment of the present invention. In this case, the heating wire 30 is provided between the first seal lip 32a and the second seal lip 32b in the seal body. Thereby, since heat can be applied to both the first seal lip 32a and the second seal lip 32b with one heating wire 30, the number of parts can be reduced, the apparatus can be simplified, and the cost can be reduced. Reduction can be achieved. In the sealing device shown in FIG. 5, the same components as those of the sealing device shown in FIGS. 1 to 4 are denoted by the same reference numerals as those in FIGS.

  As a modification of each of the above embodiments, as shown in FIG. 6, the heating wire 30 may have a shape meandering on the circumference of the seal member 26. Thereby, the sealing performance of the seal lips 32a and 32b can be maintained.

  FIG. 7 shows a sealing device according to a fourth embodiment of the present invention. In this case, the garter spring 27 is used as a heating wire. In other words, the garter spring 27 is made of a material having good electrothermal property, for example, a metal such as a nickel chromium alloy or an iron chromium alloy, and is connected to a power supply (not shown). As a result, when the power is turned on, current can be supplied to the garter spring 27 to cause the garter spring 27 itself to generate heat, and this heat is also transmitted to the seal body 28 to raise the temperature of the seal lips 32a and 32b. Can do. For this reason, it is not necessary to separately provide the heating wire 30 as shown in FIG. In this case, the garter spring 27 may meander as shown in FIG.

  Further, as the fifth embodiment, the seal member 26 includes an elastic body in which conductive materials that generate an electrothermal effect are mixed. In the present embodiment, the seal body 28 is an elastic body in which conductive materials that generate an electrothermal effect are mixed. That is, the seal body 28 is made of, for example, a material made of nitrile rubber and connected to a power source that generates an electrothermal action. Thus, when the power is turned on, current can be supplied to the seal body 28 to cause the seal body 28 itself to generate heat, and the temperature of the seal lips 32a and 32b can be raised. For this reason, even in the fifth embodiment, it is not necessary to separately provide the heating wire 30 as shown in FIG.

  Thus, in the sealing devices of the fourth embodiment and the fifth embodiment, it is not necessary to separately provide the heating wire 30, the device can be further simplified, and the cost can be further reduced. In the sealing device shown in FIG. 7, the same components as those of the sealing device shown in FIGS.

  As described above, the embodiments of the present invention have been described. However, the present invention is not limited to the above-described embodiments, and various modifications can be made. For example, the oil seal 24 may have various shapes. For example, one without the second seal lip 32 b or one without the garter spring 27 may be used. The seal body 28 may be in sliding contact with the raceway ring 9a. In the first to third embodiments, the heating wire 30 is provided in the seal body 28, but the heating wire 30 may be disposed so as to contact the surface of the seal body 28. The temperature sensor 35 may be a non-contact type disposed near the seal member 26. The part to be heated may be the entire seal member 26 (that is, the seal body 28 and the garter spring 27) or the entire seal body 28. The sealing device of the present invention may be applied to the shaft end side, and the first to fifth embodiments may be combined.

2 Outer ring 4 Inner ring 6 Tapered roller 8 Cage 9 Bearing ring 10 Rolling bearing 26 Seal member 27 Garter spring 29 Seal surface 30 Heating wire 32 Sliding contact portion 35 Temperature sensor 36 Control means

Claims (10)

In a sealing device including a seal member having a sliding contact portion that is in sliding contact with a seal surface of a bearing ring of a rolling bearing, and sealing a bearing space between a pair of bearing rings,
The sealing device is characterized in that a heating wire that generates heat by supplying current is disposed along a circumferential direction, and at least the sliding contact portion is heated by supplying current to the heating wire.   The sealing device according to claim 1, wherein the seal member includes a garter spring that presses the sliding contact portion against the seal surface, and the garter spring is the heating wire.   The sealing device according to claim 1, wherein the seal member includes a plurality of the sliding contact portions, and the heating wire is provided between adjacent sliding contact portions in the seal member.   The sealing device according to any one of claims 1 to 3, wherein the heating wire has a shape meandering on a circumference of the seal member.   The sealing device according to any one of claims 1 to 4, wherein the heating wire is made of a nickel chromium alloy or an iron chromium alloy. In a sealing device including a seal member having a sliding contact portion that is in sliding contact with a seal surface of a bearing ring of a rolling bearing, and sealing a bearing space between a pair of bearing rings,
The sealing device includes an elastic body mixed with a conductive material that generates an electrothermal effect, and heats at least the sliding contact portion by supplying a current to the elastic body.   The sealing device according to any one of claims 1 to 6, wherein a temperature sensor is provided in the seal member or in the vicinity of the seal member.   8. The sealing device according to claim 7, further comprising control means for controlling a supply amount of a current to be supplied according to a temperature detected by the temperature sensor. In a rolling bearing comprising an inner ring, an outer ring, a rolling element interposed between the inner ring and the outer ring, and a cage that holds the rolling element at a predetermined circumferential interval,
A rolling bearing comprising the sealing device according to any one of claims 1 to 8.   The rolling bearing according to claim 9, wherein the rolling bearing is used for a railway vehicle axle bearing.

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