JP2016188706A - Rolling bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent impairment of sealing property of a seal ring with a filter equipped to a rolling bearing.SOLUTION: A rolling body 13 is assembled between an outside track ring 11 and an inside track ring 12, and an opening at at least one end of a bearing space formed between the outside track ring 11 and the inside track ring 12 is covered with a seal ring 20. A filter 23 covering an oil passage hole 22 formed on the seal ring 20 catches foreign substances contained in lubrication oil. The seal ring 20 is locked to one of the outside track ring 11 and the inside track ring 12, and an annular member 40 made from material softer than the seal ring 20 is fixed to the seal ring 20. The annular member 40 constitutes a lip portion 41 opposing to or abutting on the other of the outside track ring 11 and the inside track ring 12.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rolling bearing that is oil-lubricated, and more particularly to a rolling bearing that is lubricated with oil flowing through a filter.

Rolling bearings are incorporated in transmissions such as automobiles and various construction machines, power transmission mechanisms such as differentials, reduction gears, and traveling devices including them.
In this type of apparatus, there is a structure in which the rolling bearing is lubricated with oil common to the oil that lubricates the power transmission mechanism.

  However, oil contained in a case of a power transmission mechanism such as a transmission, a differential, and a speed reducer contains a relatively large amount of foreign matter such as gear wear powder (iron powder or the like). When the foreign matter enters the inside of the rolling bearing, the raceway surface and the rolling surface are peeled off due to the biting of the foreign matter, thereby reducing the durability of the rolling bearing.

  For this reason, a rolling bearing with a filter in which a filter is provided in a seal ring attached to the rolling bearing has been proposed in order to prevent the entry of foreign matter. In this rolling bearing with a filter, a filter for capturing foreign matter is attached to an oil passage hole for oil circulation provided in a seal ring (see, for example, Patent Documents 1 and 2).

JP-A-6-323335 JP 2002-250354 A

  In the rolling bearings with a filter described in Patent Documents 1 and 2, an oil passage hole is provided in a seal ring made of an elastomer material (hereinafter, the seal ring made of an elastomer material is particularly referred to as an “elastic seal member”). The oil passage hole is covered with a filter.

  However, in such a rolling bearing, the elastic seal member is exposed to the bearing opening, that is, the seal mounting portion without the cored bar. For this reason, when some external force is applied to the elastic seal member at the time of bearing assembly, transportation, or when incorporating a mechanical device, the sealing performance is impaired by the elastic seal member being deformed or deviating from a normal assembled state. there is a possibility.

  Further, in order not to impair the sealing performance and to extend the life of the seal ring, it is necessary to accurately manage the interference between the elastic seal member and the bearing.

However, since the elastic seal member is directly attached to the bearing, in order to further improve the accuracy of the tightening allowance, the accuracy of the dimensions of the elastic seal member and the bearing must be further increased. Such further improvement in accuracy leads to an increase in manufacturing cost. Further, there is a limit to the dimensional management of the elastic seal member that is a molded product.
On the other hand, if the tightening margin is increased to ensure sealing performance, the torque of the bearing is increased. Furthermore, when applied to a bearing having a different bearing size (particularly the radial dimension between the inner and outer rings on which the elastic seal member is mounted), it is necessary to prepare a separate elastic seal member, which is disadvantageous in terms of manufacturing cost.

  Moreover, in the rolling bearing with a filter described in the said patent documents 1 and 2, it is thought that the filter is being fixed to the oil passage hole provided in the seal ring by an adhesive agent or fitting. This is because it is difficult to form an extremely thin mesh member constituting the filter integrally with a resin or the like in the same mold at the same time as the molding of the relatively thick seal ring.

  For this reason, deformation of the seal ring due to thermal expansion may cause the filter to fall off, such as a part of the fixed portion of the filter may be detached from the seal ring, or the filter may be completely detached from the seal ring. is there.

  If the filter falls off, foreign matter easily rolls and enters the inside of the bearing, so that the seal ring needs to be replaced. Replacing the seal ring is an operation that involves at least the disassembly of the power transmission mechanism, and is not always easy. For this reason, it is desirable that the filter has a structure that does not easily drop off.

  Also, a method of insert molding a prefabricated filter into a seal ring is conceivable so that the filter can be fixed more firmly. If the filter is insert-molded into the seal ring, the outer peripheral portion of the filter is held in a state of being embedded in resin or rubber that is a material of the seal ring. For this reason, the filter is less likely to drop off.

  However, even if the filter is insert-molded into the seal ring, if the degree of thermal expansion of the seal ring increases, the filter cannot follow the thermal expansion, and the mesh may be damaged or the holes may be damaged. There is. When the filter is damaged, foreign matter enters the rolling bearing side through the damaged portion, so that the seal ring can no longer function to capture the foreign matter.

  Further, when the degree of thermal expansion of the seal ring increases, the seal ring itself may swell to the outer diameter side and may completely fall off from the inner race. In such a state, foreign matter enters the rolling bearing side through the gap of the drop-off portion, and similarly, the seal ring can no longer function to capture the foreign matter.

  Accordingly, the first object of the present invention is to prevent the sealing performance of a seal ring with a filter provided in a rolling bearing from being impaired. When the filter is insert-molded into the seal ring, the seal ring is heated. A second problem is to enable the function of capturing foreign matter even when expanded.

  In order to solve the first problem, the present invention incorporates a rolling element between an outer race and an inner race, and at least a bearing space formed between the outer race and the inner race. An opening at one end is covered with a seal ring, and a foreign substance contained in the lubricating oil is captured by a filter that covers an oil passage hole formed in the seal ring, and the seal ring is the outer raceway or the inner raceway. An annular member made of a material softer than the seal ring is fixed to one of the rings, and the annular member has a gap on the other of the outer race ring or the inner race ring. A rolling bearing characterized in that a lip portion facing or abutting is formed is employed.

That is, an annular member made of a material softer than the seal ring is fixed to a seal ring locked to one of the outer race ring or the inner race ring, and the outer race ring or the inner race ring is fixed by the ring member. A lip portion facing or abutting with a gap is formed on the other side.
According to this configuration, the seal ring fixed to the race ring is a material that is relatively hard compared to the annular member constituting the lip portion, and thus is resistant to deformation against external force, that is, deformed against external force. Hateful. For this reason, the filter is firmly fixed to the main body of the seal ring, which is a material that is difficult to deform, and only the annular member constituting the soft and relatively easily damaged lip portion is attached to the main body of the seal ring. It can be exchangeable. Therefore, as a result, the life of the seal member and the bearing using the seal ring can be extended.

Further, by making the annular member constituting the lip portion and the seal ring fixed to the race ring separate from each other, the position of the annular member relative to the seal ring in the bearing width direction can be adjusted. In this way, the lip tightening allowance of the seal ring can be easily adjusted. As a result, the lip tightening allowance can be readjusted when the lip portion is worn, and a seal ring or an annular member can be used for a bearing of another model number having a different width dimension.
Furthermore, the seal ring and the annular member, which are separately formed, are prevented from rotating in the circumferential direction by bonding or a rotation prevention mechanism, so that the seal ring and the annular member are worn by relative sliding between the seal ring and the ring member. It is also possible to prevent the performance from decreasing.

In these configurations, the material of the seal ring and the ring member is free as long as the ring member is a material softer than the seal ring. For example, the seal ring is made of resin or metal. The annular member may employ a configuration made of an elastomer material that is a softer material than the resin or metal that forms the seal ring, that is, a configuration made of rubber.
Moreover, as a raw material of this seal ring, glass fiber reinforced resin is employable, for example. Glass fiber reinforced resin is a material that has higher rigidity than an elastomer alone and is difficult to deform against external force. For this reason, if such a material is employed, it is effective to ensure sealing performance.

  In each of these configurations, the material of the filter is free, but a configuration in which the filter material is a mesh member made of, for example, resin or metal can be employed.

  Moreover, in order to solve said 2nd subject, this invention, in each said structure, the said filter and the said seal ring are integral by insert molding, The material of the said filter is the same material as the said seal ring Or a material having substantially the same linear expansion coefficient or a material having a linear expansion coefficient greater than or equal to the linear expansion coefficient of the seal ring can be employed.

  Since the filter and the seal ring are made of the same material, a material having substantially the same linear expansion coefficient, or the filter having a linear expansion coefficient equal to or greater than that of the seal ring, the seal ring is heated. Even if expanded, the filter expands to the same extent following the thermal expansion of the seal ring, or the filter expands larger than the expansion amount of the seal ring. For this reason, it does not cause damage such as a broken mesh or a hole in the filter.

  As a material for the filter and seal ring, for example, a polyamide resin can be employed. In addition, when the filter and seal ring are different materials, they are materials of approximately the same linear expansion coefficient that are approximate to the extent that they do not cause damage to the filter during thermal expansion in the assumed temperature environment. It is necessary to be. At this time, it is more preferable that the materials are materials having the same linear expansion coefficient.

  In each of these configurations, the mesh member constituting the filter preferably has a mesh size of 0.3 mm to 0.7 mm. In particular, the mesh size is desirably 0.5 mm.

In other words, if the filter mesh provided on the seal ring is too large, large foreign objects will enter the bearing, and large indentations that will affect the life of the bearing will be formed on the raceway surface and rolling surface of the bearing. Become. On the other hand, if the mesh is made too small, the mesh may be clogged with foreign matter, and lubricating oil may not be supplied to the bearing.
Therefore, by conducting a life test, the size of the indentation generated on the raceway surface and rolling surface of the bearing and the rate of decrease in the life of the bearing due to the indentation are investigated. Confirmed not to give. In addition, an experiment confirmed the relationship between the mesh size and the size of the indentation formed by foreign matter that passed through the mesh.

The mesh size, that is, the size of the mesh means an opening of the mesh. In the experiment, it was confirmed that when the size of the indentation formed on the raceway surface and the rolling surface of the bearing exceeds 1 mm, the life of the bearing rapidly decreases. In addition, it was confirmed that the mesh size capable of preventing the intrusion of foreign matters that would cause indentations exceeding 1 mm in size was 0.5 mm or less. For this reason, if the mesh size is 0.5 mm or less, the life of the bearing is particularly good.
By setting the filter size to 0.7 mm or less, the indentation that can be generated is 1.3 mm or less. If the indentation is 1.3 mm or less, it is possible to suppress the decrease in the life of the rolling bearing to a certain level (life ratio of 0.6 with respect to the one without the indentation). In order to prevent clogging, the mesh size is desirably 0.3 mm or more.

  In addition, under the environment where the seal ring in the rolling bearing is used, the seal ring mainly thermally expands toward the outer diameter side as the temperature of oil or the like rises. The seal ring in the state where the maximum temperature expected under the usage environment, that is, the maximum amount of thermal expansion, is still in the expanded state, and there is still a gap for harmful foreign objects to enter between the inner ring and the inner ring. Not required.

  As a specific configuration that does not cause the gap, the seal ring includes at least a locking portion that is locked to the inner race, and a wall portion that rises from the locking portion toward the outer diameter side, The locking ring provided on the inner diameter side of the seal ring enters the recess provided in the inner raceway so that the seal ring can move in the radial direction with respect to the inner raceway during thermal expansion. It can be set as the structure latched in this way.

  According to this configuration, the locking portion provided on the inner diameter side of the seal ring enters and is locked into the recess of the inner race, and within the limit that the locking portion and the recess are locked, It is set so that thermal expansion of the seal ring can occur. In other words, under the temperature environment assumed for the seal ring, the state in which the locking portion always enters the concave portion is maintained, so that there is still a gap for harmful foreign substances to enter the inner race after the thermal expansion. Does not occur.

The seal ring is provided with a lip portion that abuts on the outer race or is opposed to the outer ring with a small gap by an annular member fixed on the outer diameter side thereof.
For example, when the lip portion faces the outer raceway with a minute gap, oil circulation through the minute interval is allowed. This is the case when the tip of the seal ring constitutes a labyrinth seal portion. However, since the gap is very small, the entry of harmful foreign matters to the rolling bearing side is prevented. In addition, the minute gap may be narrowed or closed due to thermal expansion of the seal ring.
Further, for example, when the lip portion is in contact with the outer race, the lip portion is a softer material than the seal ring, so even if the seal ring is thermally expanded, the elasticity of the material causes the lip portion to Contact is maintained.

  In each of these configurations, it is sufficient that the locking portion enters into the concave portion of the inner race and is locked so that harmful foreign substances do not enter between the seal ring and the inner race. The recess may be, for example, an end surface of the inner race or an outer diameter surface.

Moreover, the structure which made the recessed part of the inner track ring the seal groove formed along the circumferential direction is employable.
In the configuration, the locking portion includes a protruding portion provided at an inner diameter side end portion of the wall portion, and the concave portion is a circumferential seal groove formed in the inner race, and the protruding portion Is inserted into the seal groove, so that the seal ring is locked to the inner race so as to be movable in the radial direction during thermal expansion.

  In addition, the latching | locking part and recessed part which mutually latch may be arrange | positioned intermittently along the circumferential direction, and may be continuous over the perimeter.

  In each of these configurations, the type of the rolling bearing to which the seal ring is attached is free. For example, a tapered roller bearing using a tapered roller as a rolling element may be used, or a ball may be used as the rolling element. It may be a deep groove ball bearing, a cylindrical roller bearing using cylindrical rollers, or a self-aligning roller bearing using spherical rollers.

  In the case where the rolling bearing is a tapered roller bearing, the seal groove may be formed so as to open to the outer diameter surface of the inner collar of the inner race. Further, when the rolling bearing is a deep groove ball bearing, a cylindrical roller bearing, or a self-aligning roller bearing, the seal groove is formed to open on the outer diameter surface of the end of the inner race of the rolling bearing. It can be set as the structure currently made.

Further, in the configuration provided with a protruding portion as the locking portion, the protruding portion includes an inner protruding portion on the side close to the rolling element and an outer protruding portion on the far side, and the seal groove includes the inner protruding portion. It is possible to adopt a configuration including an inner seal groove into which the outer protrusion enters and an outer seal groove into which the outer protrusion enters.
According to this configuration, since the locking portion of the seal ring includes the two protrusions along the axial direction, the seal ring is more reliably engaged with the inner race by the two protrusions having different axial positions. You can stop.

Further, the depth at which the inner protrusion enters the inner seal groove can be configured to be shallower than the depth at which the outer protrusion enters the outer seal groove.
According to this configuration, when the seal ring is pushed into the opening of the bearing space and fixed, the inner projecting portion located on the deeper side can be elastically deformed or heat deformed, and can be easily fitted into the seal groove. Moreover, since the penetration depth of the outer protrusion located on the near side with respect to the seal groove is deep, the engagement between the seal ring and the inner race can be maintained even with respect to thermal expansion in a large outer diameter direction.

In addition, the said inner side protrusion part and the said outer side protrusion part may each be provided continuously over the perimeter of a circumferential direction, respectively, and may each be provided intermittently along the circumferential direction. That is, the inner protrusion may be intermittent along the circumferential direction and the outer protrusion may be continuous along the circumferential direction. Alternatively, the inner protrusion may be continuous along the circumferential direction, and the outer protrusion may be intermittent along the circumferential direction. Both can be continuous or intermittent.
Further, the inner protrusions and the outer protrusions can be arranged alternately along the circumferential direction. If the inner protrusions and the outer protrusions are alternately arranged in the circumferential direction, the inner protrusion is less likely to enter the blind spot of the outer protrusion when the seal ring is pushed into the bearing space and fixed. For this reason, it is easy to visually confirm that the inner projecting portion on the back side is fitted in the seal groove.

  In the configuration including the inner protruding portion and the outer protruding portion, it is possible to adopt a configuration in which at least the outer protruding portion is movable in the axial direction within the outer seal groove. If the outer protrusion is movable in the axial direction in the outer seal groove, the outer protrusion can smoothly move in the radial direction in the seal groove when the seal ring is thermally expanded. For this reason, the outer protrusion is not restrained in the seal groove, and it is possible to prevent the pulling force in the outer diameter direction due to thermal expansion from acting on the seal ring, and to avoid damage to the filter.

  In these configurations, it is possible to adopt a configuration in which the outer seal groove is formed to be open at an end surface of the inner race. The outer projecting part having a deep penetration depth into the seal groove is assumed to be difficult to fit into the seal groove (a state in which the outer projecting part is bent in the seal groove). In addition, if the outer seal groove is opened on the end face of the inner race, the fitting is easy.

  At this time, the end surface of the inner raceway is brought into contact with a shaft shoulder fitted and fixed to the inner diameter of the inner raceway, and the opening of the end surface of the outer seal groove is closed by the shaft shoulder. A configuration can be employed. According to this configuration, the outer protrusion is securely held in the outer seal groove. That is, after the outer protrusion is fitted into the outer seal groove, the opening on the end surface of the outer seal groove can be closed with the shaft shoulder.

  In the present invention, an annular member made of a material softer than the seal ring is fixed to a seal ring locked to one of the outer race ring or the inner race ring, and the outer race ring or the inner race ring is fixed by the annular member. A lip portion facing or abutting with a gap is formed on the other of the race rings. For this reason, since the seal ring fixed to the raceway ring is a relatively hard material as compared with the annular member constituting the lip portion, it is resistant to deformation against external force, that is, hardly deformed against external force. The filter is firmly fixed to the main body of the seal ring, which is a material that is difficult to deform, and only the annular member constituting the soft and relatively easily damaged lip portion is replaced with the main body of the seal ring. Can be possible. Therefore, the life of the seal ring using these and the bearing using the seal ring can be extended.

  Further, in the present invention, the filter and the seal ring are made of the same material, a material having substantially the same linear expansion coefficient, or the filter is made of a material having a linear expansion coefficient equal to or higher than the linear expansion coefficient of the seal ring. Even if the seal ring thermally expands, the filter expands to the same extent following the thermal expansion of the seal ring, or the filter expands larger than the expansion amount of the seal ring. For this reason, it does not cause damage such as a broken mesh or a hole in the filter. Therefore, even when the seal ring is thermally expanded, the function of capturing foreign matter can be continuously exhibited.

The principal part expanded sectional view which shows 1st embodiment of this invention (A) (b) is the principal part enlarged view of FIG. The detail of a seal ring is shown, (a) is a principal part expanded side view, (b) is a principal part enlarged plan view (A) and (b) are perspective views showing details of a seal ring In FIG. 1, the principal part enlarged view which shows the state which inserted the member for dimension adjustment. The principal part expanded sectional view which shows 2nd embodiment of this invention The principal part expanded sectional view which shows 3rd embodiment of this invention The principal part expanded sectional view which shows 4th Embodiment of this invention (A) (b) is explanatory drawing of the mesh size of a filter (A) is a graph showing the relationship between the size of the indentation and the life reduction rate, and (b) is a graph showing the mesh size and the size of the indentation. Longitudinal cross section of traveling device Overall view of mine dump truck

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an enlarged cross-sectional view of a main part of a rolling bearing 10 according to the present invention.

  This rolling bearing 10 is incorporated in the traveling device 4 of the mining dump truck (construction machine) 1 shown in FIG. In the mine dump truck 1, a chassis 2 that supports a loading platform and a cab is supported by a plurality of drive wheels (tires) 3. The traveling device 4 transmits power to the drive wheels 3.

As shown in FIG. 11, the travel device 4 includes a travel motor 5 that is a drive source and a shaft 6 that is connected to the rotation shaft of the travel motor 5. A speed reducer is disposed as a power transmission mechanism T on the outer side of the tip portion of the shaft 6.
Further, a spindle 7 that forms a fixed axle is disposed outside the shaft 6. A wheel 9 is arranged outside the spindle 7 via a rolling bearing 10. The rotation of the wheel 9 is transmitted to the drive wheel 3 via the rim 8.

  In this traveling device 4, a planetary gear mechanism 50 is employed as a speed reducer. The planetary gear mechanism 50 includes a first planetary gear mechanism 50a and a second planetary gear mechanism 50b, and the rotation of the shaft 6 is decelerated and transmitted to the wheel 9 via the two planetary gear mechanisms 50a and 50b. However, the configuration of the speed reducer is not limited to this example, and a speed reduction mechanism using a planetary gear mechanism having another configuration or a known speed reduction mechanism other than the planetary gear mechanism can be employed.

  In this traveling device 4, a double row tapered roller bearing is employed as the rolling bearing 10 between the spindle 7 and the wheel 9. The drive wheel 3 is supported on the axle via the double-row tapered roller bearing. In this type of construction machine, a tapered roller bearing is often used as the rolling bearing 10 in order to have a structure capable of withstanding a large radial load.

  As shown in FIG. 11, the rolling bearing 10 includes a tapered roller as a rolling element 13 between the raceway surfaces 11 a and 12 a of the outer raceway ring 11 and the inner raceway ring 12. The rolling element 13 is held in the circumferential direction by a cage 14.

  The parallel rolling bearings 10 are arranged so that the small diameter side end faces of the tapered rollers are back to back. In other words, the raceway surface 12 a of the inner raceway ring 12 and the raceway surface 11 a of the outer raceway ring 11 go from the axially outer side of the two rows of rolling bearings 10, 10 to the central portion between the two rows of rolling bearings 10, 10. It is provided so that a mutual distance may become narrow toward the side which goes.

  Moreover, the preload is given to each rolling element 13 by pressing the inner track 12 with respect to the outer track 11 toward the direction where the distance becomes narrower. This preload is caused by tightening the bearing retainer 17 shown in FIG. 11 with a bolt 17a with respect to the spindle 7 so that the inner bearing rings 12 and 12 are in the axial direction between the bearing retainer 18 on the opposite side. It can be applied by applying a compressive force to the.

  The power transmission mechanism T and the rolling bearing 10 are lubricated with a common lubricating oil. That is, since the oil is stored up to a certain level in the casing of the traveling device 4, at least the lower part of the power transmission mechanism T and the rolling bearing 10 is immersed in the oil. Thereby, the components of the power transmission mechanism T and the rolling bearing 10 are lubricated.

  The inner race 12 is mounted on an axle (the spindle 7) that is a non-rotating shaft and cannot rotate. Further, the outer race 11 is mounted so as to rotate integrally with the rotary housing H. The rotary housing H is formed as a member integral with the wheel 9 of the drive wheel 3 or is coupled to the wheel 9 so as to be rotatable.

Further, in the casing, an oil flow path from the power transmission mechanism T side to the rolling bearing 10 side is provided on the side close to the power transmission mechanism T of the rolling bearing 10. That is, since the power transmission mechanism T and the rolling bearing 10 are lubricated with common oil, the oil transmission path between the power transmission mechanism T and the rolling bearing 10 is a mutual passage.
In this embodiment, since the two rolling bearings 10 are provided in parallel in the axial direction, the oil flow path is an opening on the power transmission mechanism T side of the rolling bearing 10 on the side close to the power transmission mechanism T, that is, This is an opening on the side of the power transmission mechanism T in a bearing space formed between the outer race ring 11 and the inner race ring 12. FIGS. 1 and 2 show a main part of the rolling bearing 10 on the side close to the power transmission mechanism T, and the right side in the figure is the opening on the power transmission mechanism T side.

A seal member S is attached to the rolling bearing 10 on the power transmission mechanism T side. As shown in FIG. 11, the seal member S is attached so as to cover the opening on the power transmission mechanism T side in the bearing space of the rolling bearing 10 on the power transmission mechanism T side.
If necessary, a similar seal member S may be attached to the opening on the opposite side of the power transmission mechanism T in the rolling bearing 10 far from the power transmission mechanism T.

  As shown in FIG. 1, the seal member S includes a locking portion 21 that is locked to the inner race 12 of the rolling bearing 10, and a wall portion 25 that rises from the locking portion 21 toward the outer diameter side. The seal ring 20 (the main body of the seal ring) is integrally provided with a lip mounting portion 27 provided at the outer diameter side end of the wall portion.

The seal ring 20 is made of resin, and a filter 23 made of the same resin is integrated by insert molding so as to cover the oil passage hole 22 formed in the wall portion 25 of the seal ring 20.
The filter 23 is located substantially at the center in the length direction of the oil passage hole 22 (the thickness direction of the seal ring 20). The peripheral portion of the filter 23 is embedded and fixed in the resin of the seal ring 20 around the oil passage hole 22.

  Since the material of the filter 23 and the material of the seal ring 20 are the same resin material, the material of the filter 23 and the material of the seal ring 20 have the same thermal expansion coefficient. For this reason, even if the seal ring 20 is thermally expanded due to the temperature rise of the lubricating oil in the rolling bearing 10, the filter 23 expands to the same extent following the thermal expansion of the seal ring 20. Therefore, damage such as a broken mesh or a hole in the filter 23 is not caused.

  In this embodiment, a polyamide resin or the like is used as a material for the filter 23 and the seal ring 20, but other resins may be used. Examples of other resins include polyacetal (POM), polycarbonate (PC), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and polytetrafluoroethylene. (PTFE), polysulfone (PSF), polyethersulfone (PES), polyimide (PI), polyetherimide (PEI), and the like. Moreover, it is good also as glass fiber reinforced resin using those resins. As the glass fiber reinforced resin, for example, PA (polyamide) 46 + GF or PA (polyamide) 66 + GF can be employed.

The blending ratio of the glass fiber is optimized from the shrinkage ratio of the resin and the required strength, and is, for example, 15 to 35%, more preferably 25 to 30%. In general, when the glass fiber blending ratio is large, the shrinkage rate becomes small, and dimensional management after molding becomes easy. On the contrary, if the glass fiber blending ratio is small, the strength of the resin is lowered and the resin is easily deformed. Therefore, the optimal blending ratio between the shrinkage rate and the strength is 25 to 30%.
In addition to glass fiber reinforced resin, carbon fiber reinforced resin, polyethylene fiber reinforced resin, aramid fiber reinforced resin, or the like can be used as a material for these filter 23 and seal ring 20.

In this embodiment, the filter 23 and the seal ring 20 are made of the same material, and they are integrated by insert molding. However, the material of the filter 23 is not limited to the same material as the seal ring 20, A material having substantially the same linear expansion coefficient as the material of the seal ring 20 or a material having a linear expansion coefficient equal to or greater than the linear expansion coefficient of the seal ring 20 may be used.
Even in such a configuration, the filter 23 expands to the same extent following the thermal expansion of the seal ring 20, or the filter 23 expands larger than the expansion amount of the seal ring 20. It can be prevented from being damaged without being pulled.

  In addition, when there is no need to worry about damage to the filter during thermal expansion of the seal ring 20, any material can be used for the filter 23 and the seal ring 20 regardless of the numerical value of the linear expansion coefficient.

  As shown in FIG. 1, an annular member 40 is fixed to the lip mounting portion 27 of the seal ring 20. The annular member 40 is made of rubber and is a softer material than the material of the seal ring 20. The annular member 40 is fitted and fixed to the outer periphery of the lip mounting portion 27 and is in close contact with the lip mounting portion 27 due to its elasticity. As a material of the annular member 40, for example, nitrile rubber, acrylic rubber, urethane rubber, fluoro rubber, or the like can be used for synthetic rubber.

  The annular member 40 fixed to the lip mounting portion 27 constitutes a lip portion 41 that contacts the outer raceway ring 11. Since the seal ring 20 fixed to the inner race 12 is a relatively hard material compared to the annular member 40 constituting the lip portion 41, the seal ring 20 is resistant to deformation due to external force, that is, hardly deformed against external force. . For this reason, the filter 23 is firmly fixed to the main body of the seal ring 20 which is a material that is not easily deformed, and only the annular member 40 constituting the lip portion 41 that is soft and relatively easily damaged is sealed. The body of the ring 20 can be exchangeable. Therefore, as a result, the life of the seal member S and the bearing using the seal member S can be extended.

  Further, by making the annular member 40 constituting the lip portion 41 and the seal ring 20 fixed to the inner race 12 separate, the position of the annular member 40 in the bearing width direction with respect to the seal ring 20 is determined. It can also be adjustable. This adjustment is possible, for example, by inserting a dimension adjusting member 28 between the axially outer end surface 40a of the annular member 40 and the inner end surface 27a of the lip mounting portion 27 as shown in FIG. . If the dimension adjusting member 28 is a plate-shaped member (shim), the adjustment dimension can be easily set by preparing various members having different thicknesses.

  In this way, if the position of the annular member 40 relative to the seal ring 20 can be adjusted, the lip tightening allowance of the seal member S can be easily adjusted. Thereby, in addition to being able to readjust the lip tightening allowance when the lip portion 41 is worn, the seal ring 20 and the annular member 40 can also be used for bearings of different model numbers having different width dimensions.

Further, the seal ring 20 and the annular member 40 molded separately are prevented from rotating in the circumferential direction by an adhesion or a rotation preventing mechanism, thereby causing a relative slip between the seal ring 20 and the annular member 40. It is also possible to prevent the sealing performance from being deteriorated due to wear. In the case where the annular member 40 is bonded and fixed to the seal ring 20, for example, a general adhesive can be used, and a technique by vulcanization bonding can also be employed. The adhesion surface is between the axially outer end surface of the annular member 40 and the inner end surface 27a of the lip mounting portion 27, and between the inner peripheral surface 40b of the annular member 40 and the outer peripheral surface 27b of the lip mounting portion 27. It is desirable to do.
In addition, it is desirable that the annular member 40 has a structure that can prevent slippage in the rotational direction more reliably by fitting in the radial direction with not only adhesion but also tightening allowance. However, if the adhesion is omitted by using a detent mechanism, the annular member can be easily replaced.

  In addition, as shown in FIG. 3, the oil passage hole 22 of this embodiment comprises a long hole having a rectangular shape in a side view. A plurality of oil passage holes 22 are provided at intervals along the circumferential direction of the seal ring 20. The shape, number, and arrangement interval of the oil passage holes 22 can be set as appropriate. The shape of the oil passage hole 22 may be a shape other than a long hole having a rectangular shape in a side view, and may be a long hole having an arc shape in a side view, for example.

  As a configuration of the filter 23, a mesh-like resin having a mesh size of about 0.1 to 1 mm can be employed. Here, a mesh-like resin having a mesh size of 0.5 mm is used, but the mesh size of the filter 23 can be appropriately set according to the diameter of a foreign substance to be captured. An optimal mesh size that can ensure a long bearing life will be described later.

  When the locking portion 21 provided on the inner diameter side of the seal ring 20 enters the circumferential seal groove (concave portion) 30 provided in the inner race 12, the inner race 12 is subjected to thermal expansion. On the other hand, it is locked so as to be movable in the radial direction.

  The configuration of the locking portion 21 and the seal groove 30 will be described in detail. As shown in FIGS. 2 to 4, the locking portion 21 of the seal ring 20 is located on the inner diameter side provided at the inner diameter side end of the wall portion 25. Protruding portion 24 is provided.

  The protruding portion 24 includes an inner protruding portion 24a on the side closer to the rolling element 13 and an outer protruding portion 24b on the far side. Further, the seal groove 30 includes an inner seal groove 30a into which the inner protrusion 24a enters and an outer seal groove 30b into which the outer protrusion 24b enters.

When the projecting portion 24 enters the seal groove 30, the seal ring 20 is locked to the inner race 12 so as to be movable in the radial direction during thermal expansion.
Further, since the projecting portion 24 is composed of two projecting portions 24a and 24b along the axial direction, the seal ring 20 is more reliably guided to the inner track by the two projecting portions 24a and 24b having different axial positions. The ring 12 can be locked.

In a state (steady state) before the lubricating oil of the rolling bearing 10 rises in temperature (steady state), as shown in FIG. 2A, the depth h1 at which the inner protrusion 24a enters the inner seal groove 30a is the outer protrusion. The depth 24b is set to be relatively shallower than the depth h2 into which the outer seal groove 30b enters.
For this reason, when the seal ring 20 is pushed and fixed into the opening of the bearing space, the inner projection 24a on the back side can be easily fitted into the inner seal groove 30a by elastic deformation or heat deformation at the time of the push.

  Further, since the penetration depth h2 of the outer protrusion 24b with respect to the outer seal groove 30b is relatively deep, the outer diameter of the seal ring 20 is larger as in the state after the temperature rise (expanded state) shown in FIG. Even with respect to the amount of thermal expansion in the direction, the outer protrusion 24b and the outer seal groove 30b can remain locked. In other words, the engagement between the seal ring 20 and the inner race 12 can be maintained, and even in this expanded state, no gap is created in which harmful foreign substances enter the rolling bearing 10.

At this time, the seal ring 20 in the state where the maximum temperature assumed in the rolling bearing 10, that is, the maximum amount of thermal expansion, is still in the expanded state, and harmful foreign matter is still between the inner race 12. The penetration depth h2 of the outer protrusion 24b into the outer seal groove 30b is set so that no gap is formed (see FIG. 2B).
For this reason, under the temperature environment assumed for the seal ring 20, the state in which the outer protruding portion 24 b always enters the outer seal groove 30 b is maintained, and a gap is formed between the inner race 12 and harmful foreign matter. I won't let you.

Moreover, in this embodiment, as shown in FIG.3 and FIG.4, the inner side protrusion part 24a and the outer side protrusion part 24b are alternately arrange | positioned along the circumferential direction.
As described above, when the inner protrusions 24a and the outer protrusions 24b are alternately arranged in the circumferential direction, the inner protrusion 24a is formed on the outer protrusion 24b when the seal ring 20 is pushed into the bearing space and fixed. It is difficult to enter the blind spot. For this reason, it is easy to visually confirm that the inner projecting portion 24a on the back side is fitted in the inner seal groove 30a. 1 and 2, a cross-sectional view corresponding to the II-II cross section of the seal ring 20 shown in FIG. 3B is described, and the positional relationship between the inner protrusion 24 a and the outer protrusion 24 b and the protrusion height. Can be compared.

Moreover, in this embodiment, the inner side protrusion part 24a and the outer side protrusion part 24b are arrange | positioned so that an overlapping part may not arise in the circumferential direction. That is, the azimuth directions around the axes of the inner protrusions 24a at both ends in the circumferential direction coincide with the azimuth directions around the axes at the circumferential ends of the outer protrusions 24b adjacent in the circumferential direction.
However, the arrangement of the inner projecting portion 24a and the outer projecting portion 24b is not limited to this embodiment, and the inner projecting portion 24a and the outer projecting portion 24b may be arranged such that overlapping portions are generated in the circumferential direction. Good.

  Moreover, in this embodiment, as shown to Fig.2 (a), the outer side protrusion part 24b has the axial direction clearance gap w1 between the end walls in the outer side seal groove 30b. That is, the axial width of the outer seal groove 30b is wider by the axial gap w1 than the width of the outer protrusion 24b. For this reason, the outer protrusion 24b can move in the axial direction within the outer seal groove 30b within the range of the axial gap w1.

  As described above, if the outer protrusion 24b can move in the axial direction in the outer seal groove 30b, the outer protrusion 24b is not restrained in the outer seal groove 30b when the seal ring 20 is thermally expanded. , And can move smoothly in the radial direction along with the thermal expansion. For this reason, it is possible to prevent the pulling force in the outer diameter direction due to the thermal expansion from acting on the seal ring 20, and avoid damage to the filter 23.

  At this time, the abutting portion 41d provided at the tip of the lip portion 41 is in contact with the outer race 11, so that the lip portion 41 is outside due to the elasticity of the material even if the seal ring 20 is thermally expanded. The contact with the race 11 is maintained.

The outer seal groove 30b is formed to be open at the end face of the inner race 12 as shown in FIG. Further, a shaft shoulder (shoulder portion of the axle) A that fits and is fixed to the inner diameter of the inner raceway ring 12 is brought into contact with the end surface of the inner raceway ring 12. For this reason, the opening of the end surface of the outer seal groove 30b can be closed by the shaft shoulder A after the outer protrusion 24b is fitted into the outer seal groove 30b.
In this way, if the outer seal groove 30b is opened in the end face of the inner race 12, the fitting is easy. Moreover, since the opening of the end surface can be closed by the shaft shoulder A, the outer protrusion 24b is prevented from being detached from the outer seal groove 30b.

  The operation of the seal ring 20 will be described. During use of the traveling device 4, a part of the oil is directed from the power transmission mechanism T side to the side surface of the rolling bearing 10 as the power transmission mechanism T and the rolling bearing 10 rotate. Scatter.

  At this time, since the seal ring 20 is attached to the opening on the power transmission mechanism T side in the bearing space of the rolling bearing 10, the oil scatters toward the seal ring 20. A part of the oil hitting the seal ring 20 collides with the filter 23 in the oil passage hole 22.

When the oil that has collided with the filter 23 passes through the mesh of the filter 23, foreign matters larger than the mesh size of the filter 23 are captured by the mesh among foreign matters contained in the oil. The oil that has passed through the filter 23 flows into the bearing space and lubricates the rolling bearing 10.
For this reason, it is possible to prevent foreign matter discharged from the power transmission mechanism T from entering the inside of the rolling bearing 10.

  Further, when the filter 23 is clogged with foreign matter, it can be dealt with by replacing the seal ring 20 with a new seal ring 20.

  FIG. 6 shows a second embodiment of the present invention. In this embodiment, a locking means 29 that restricts the radial movement of the seal ring 20 is provided in the locking portion 21 of the seal ring 20 and the seal groove 30 of the inner race 12. Since the other main configuration is the same as that of the above-described embodiment, the difference will be mainly described below.

As shown in FIG. 6, the locking means 29 includes a locking projection 29 a provided in the locking portion 21 of the seal ring 20 and a locking recess 29 b provided in the seal groove 30.
The locking projection 29a is provided so as to protrude in the axial direction in the middle of the protruding direction of the outer protruding portion 24b among the inner protruding portion 24a and the outer protruding portion 24b constituting the locking portion 21. The locking recess 29b is provided to be recessed in the axial direction on the inner surface of the outer seal groove 30b so that the locking projection 29a can enter.

The length of the locking recess 29b with respect to the radial direction of the bearing is longer than the length of the locking projection 29a with respect to the radial direction of the bearing by the dimension w2. For this reason, in a state where the locking projection 29a enters the locking recess 29b, the locking projection 29a can move in the locking recess 29b along the radial direction of the bearing.
In this embodiment, the length of the locking recess 29b in the circumferential direction of the bearing is the same as the length of the locking projection 29a in the radial direction of the bearing, but the length of the locking recess 29b in the circumferential direction is the same. The length can be made slightly longer than the length of the locking projection 29a. Thereby, the latching convex part 29a can move in the latching concave part 29b along the circumferential direction of the bearing.

With the locking portion 21 of the seal ring 20 accommodated in the seal groove 30 of the inner race 12, the locking projection 29 a of the seal ring 20 enters the locking recess 29 b in the sealing groove 30. The seal ring 20 is restricted from moving by a predetermined amount or more in the radial direction of the bearing, and is restricted from moving in the circumferential direction of the bearing.
Therefore, when the seal ring 20 is thermally expanded, while restricting movement of the thermally expanded seal ring 20 in the radial direction by a predetermined amount or more (particularly movement due to expansion from the cold state to the outer diameter direction) At the same time, the seal ring 20 can be prevented from rotating in the circumferential direction with respect to the inner race 12.

  Further, since the length of the locking concave portion 29b with respect to the radial direction of the bearing is slightly longer than the length of the locking convex portion 29a with respect to the radial direction of the bearing, the seal ring 20 is attached when the seal ring 20 is attached to the bearing. Even when 20 is heated, the locking projection 29a can smoothly enter the locking recess 29b.

  FIG. 7 shows a third embodiment of the present invention. In this embodiment, a positioning step portion 41 c is provided on the inner diameter portion of the annular member 40 constituting the lip portion 41. The step portion 41 c meshes with a step portion 27 c provided on the lip mounting portion 27 of the seal ring 20 to position the annular member 40 in the axial direction with respect to the seal ring 20.

  Moreover, in this embodiment, the seal ring fitting part 31 between the inner side protrusion part 24a and the outer side protrusion part 24b of the latching | locking part 21, and the inner side race ring fitting part between the inner side seal groove 30a and the outer side seal groove 30b. 32 is press-fitted with a tightening margin. This is the same in any embodiment. As described above, the press-fitting is set to a predetermined tightening allowance by heating and inflating the resin seal ring 20 and fitting the seal ring 20 into the inner race 12 in this state. Due to the tightening allowance, the sealing performance of the seal ring 20 is improved.

  FIG. 8 shows a fourth embodiment of the present invention. In this embodiment, the cross-sectional shape of the lip mounting portion 27 of the seal ring 20 is a U-shape.

  Since the lip mounting portion 27 has a U-shaped cross section, the annular member 40 is protected against an external force from the outer peripheral side with respect to the seal ring 20. Further, since the lip mounting portion 27 has a U-shaped cross section, when an adhesive or a filler is used for fixing the annular member 40, an effect of preventing leakage of the adhesive or the filler can be expected.

  In each of these embodiments, as a material of the filter 23, for example, a synthetic resin such as polyamide or a metal such as stainless steel can be employed. When the material of the filter 23 is a synthetic resin, it is effective for preventing rust and reducing the weight. Further, when the material of the filter 23 is a metal, it is possible to improve the strength and durability against hard foreign matters such as metal.

In each of these embodiments, the mesh member constituting the filter 23 desirably has a mesh size of 0.3 mm to 0.7 mm. In particular, the mesh size is desirably 0.5 mm.
Here, the mesh size means the mesh opening (opening) of the mesh structure as shown by the dimension w3 in FIGS. 9 (a) and 9 (b).

That is, if the mesh of the filter 23 provided on the seal ring 20 is too large, a large foreign matter enters the bearing, and large indentations that affect the life of the bearing are formed on the raceway surface and the rolling surface of the bearing. It will be. On the other hand, if the mesh is made too small, the mesh may be clogged with foreign matter, and lubricating oil may not be supplied to the bearing.
Therefore, by conducting a life test, the size of the indentation generated on the raceway surface and rolling surface of the bearing and the rate of decrease in the life of the bearing due to the indentation are investigated. Confirmed not to give. In addition, an experiment confirmed the relationship between the mesh size and the size of the indentation formed by foreign matter that passed through the mesh.

  10 (a) and 10 (b) show the experimental results. FIG. 10A shows the relationship between the size of the indentation generated on the raceway surface and the rolling surface of the bearing and the rate of decrease in the life of the bearing accompanying the indentation, and FIG. 10B shows the mesh size and its relationship. The relationship of the magnitude | size of the impression formed by the foreign material which passed the mesh is shown.

The test conditions were a roller bearing with a tapered roller bearing with main dimensions (inner diameter, outer diameter, width) of φ30 mm × φ62 mm × 17.25 mm, radial load 17.65 kN, axial load 1.47 kN, shaft rotation speed 2000 min. ⁻¹ .

  In the experiment, it was confirmed that when the size of the indentation formed on the raceway surface and the rolling surface of the bearing exceeds 1 mm, the life of the bearing rapidly decreases. In addition, it was confirmed that the mesh size capable of preventing the intrusion of foreign matters that would cause indentations exceeding 1 mm in size was 0.5 mm or less. For this reason, if the mesh size is 0.5 mm or less, the life of the bearing is particularly good. By setting the filter size to 0.7 mm or less, the indentation that can be generated is 1.3 mm or less. If the indentation is 1.3 mm or less, it is possible to suppress the decrease in the life of the rolling bearing to a certain level (life ratio of 0.6 with respect to the one without the indentation). In order to prevent clogging, the mesh size is desirably 0.3 mm or more.

  These embodiments are rolling bearings 10 in a traveling device 4 used for a large construction machine, with the outer race 11 being a rotation side and the inner race 12 being a stationary side. Further, the seal ring 20 is locked to the inner race 12 which is the stationary side. For this reason, the filter 23 does not move in the direction around the axis, and the foreign matter captured by the filter 23 is not easily scattered.

  The type of the rolling bearing 10 to which the seal ring 20 is attached is arbitrary. For example, it may be a tapered roller bearing using a tapered roller as the rolling element 13, or a deep groove ball bearing using a ball as the rolling element 13. Alternatively, a cylindrical roller bearing using cylindrical rollers, a self-aligning roller bearing using spherical rollers, or the like may be used.

1 Construction machinery (dump truck for mining)
2 Chassis 3 Drive wheel (tire)
4 traveling device 5 drive source (traveling motor)
6 Shaft 7 Spindle 8 Rim 9 Wheel 10 Rolling bearing 11 Outer ring (outer raceway ring)
11a Raceway surface 12 Inner ring (inner raceway)
12a Raceway surface 12b Large brim 12c Small brim 13 Tapered roller (rolling element)
14 Cage 20 Seal ring 21 Locking portion 22 Oil passage hole 23 Filter 24 Protruding portion 24a Inner protruding portion 24b Outer protruding portion 25 Wall portion 27 Lip mounting portion 27a Inner end surface 27b Outer peripheral surface 27c Step portion 28 Size adjusting member 29 Locking Means 29a Locking convex part 29b Locking concave part 30 Seal groove 30a Inner seal groove 30b Outer seal groove 31 Seal ring fitting part 32 Inner race ring fitting part 40 Ring member 41 Lip part 41a Outer end face 41b Inner peripheral face 41c Step Part 41d contact part 50 planetary gear mechanism

Claims (4)

A rolling element (13) is incorporated between the outer race (11) and the inner race (12), and a bearing space formed between the outer race (11) and the inner race (12) is formed. At least one end of the opening is covered with a seal ring (20), and foreign matter contained in the lubricating oil is captured by a filter (23) covering an oil passage hole (22) formed in the seal ring (20). The seal ring (20) is connected to the outer race (11) or the inner race (12).
), And an annular member (40) made of a material softer than the seal ring (20) is fixed to the seal ring (20). A lip portion (41) configured to face or abut against the other of the race (11) or the inner race (12) with a gap is formed
The material of the filter (23) is a material having a linear expansion coefficient equal to or greater than the linear expansion coefficient of the seal ring (20), and the filter (23) has a thermal expansion larger than the expansion amount of the seal ring (20). A rolling bearing characterized by The rolling bearing according to claim 1, wherein the seal ring (20) is made of resin or metal, and the annular member (40) is made of rubber. The rolling bearing according to claim 1 or 2, wherein the filter (23) is a mesh member made of resin or metal. The rolling bearing according to any one of claims 1 to 3, wherein the filter (23) and the seal ring (20) are integrated by insert molding.

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