JP4893648B2 - Rolling bearing unit with combination seal ring - Google Patents

Description

  The present invention exists, for example, in a rolling bearing unit for rotatably supporting a wheel of an automobile with respect to a suspension device, between circumferential surfaces facing each other of a rotation side raceway and a stationary side raceway. The present invention relates to an improvement in a rolling bearing unit with a combined seal ring in which an end opening of an annular space in which a plurality of rolling elements are installed is closed with a combined seal ring made up of a slinger and a seal ring. Specifically, it is intended to realize a structure that can favorably maintain the sealing property of the fitting surface between the rotating raceway and the slinger over a long period of time. The rolling bearing unit with a combined seal ring that is the subject of the present invention includes both a structure in which an encoder made of a permanent magnet is installed on the side surface of the slinger and a structure in which such an encoder is not installed. .

  As a rolling bearing unit for rotatably supporting a vehicle wheel with respect to a suspension device, for example, Patent Document 1 describes a structure as shown in FIG. In the rolling bearing unit 1 shown in FIG. 6, an outer ring 2 that is a stationary side race ring and a hub 3 that is a rotation side race ring are arranged concentrically with each other. And the double row outer ring raceways 4 and 4 provided on the inner peripheral surface of the outer ring 2 are each stationary side raceways, and the double row each provided on the outer peripheral surface of the hub 3 is a rotary side raceway. Between the inner ring raceways 5 and 5, a plurality of balls 6 and 6 each of which is a rolling element are arranged in each row. These balls 6 and 6 are held by the cages 7 and 7 so as to be freely rollable. With such a configuration, the hub 3 is rotatably supported on the inner diameter side of the outer ring 2 supported and fixed to the suspension device.

  Both end openings of the annular space 8 in which the balls 6, 6 are installed between the inner peripheral surface of the outer ring 2 and the outer peripheral surface of the hub 3 are formed on the entire periphery by a seal ring 9 and a combination seal ring 10, respectively. It is crawling up. Among these, the seal ring 9 includes a metal core 11 made of a metal plate and a seal lip 12 made of an elastic material. Then, with the core metal 11 being fitted into one end portion of the outer ring 2 by an interference fit, the tip edge of the seal lip 12 is brought into sliding contact with the outer peripheral surface of the intermediate portion of the hub 3 over the entire circumference. ing.

  The combined seal ring 10 includes a slinger 13 and a seal ring 14. Of these, the slinger 13 is formed by bending a metal plate to form an entire ring shape with an L-shaped cross section. The slinger 13 is bent radially outward from the cylindrical portion 15 and the axial edge of the cylindrical portion 15. And an annular section 16 and a curved surface section 17 having an arcuate cross section existing in a continuous portion of the cylindrical section 15 and the annular section 16. Such a slinger 13 is fixed to the hub 3 by externally fitting the cylindrical portion 15 to the outer peripheral surface of the end portion of the hub 3 (the inner ring constituting the hub 3 together with the hub body). Yes. The seal ring 10 includes a cored bar 18 made of a metal plate and a seal lip 19 made of an elastic material. And the tip edge of the said seal lip 19 is made to slidably contact the whole surface of the said slinger 13 in the state which the metal core 18 of these was fitted by interference fitting to the other end part of the said outer ring | wheel 2. .

  Of the two axially opposite side surfaces of the ring portion 16 of the slinger 13 constituting the combination seal ring 10 as described above, the surface of the cylindrical portion 15 opposite to the bending direction is shown in FIG. Similarly, the annular encoder 20 may be attached and fixed over the entire circumference. The encoder 20 is made of a permanent magnet such as a rubber magnet or a plastic magnet, and is magnetized in the axial direction. The magnetization direction is changed alternately and at equal intervals in the circumferential direction. Accordingly, the S pole and the N pole are alternately arranged at equal intervals in the circumferential direction on one side surface of the encoder 20 in the axial direction, which is the detected surface. For example, as described in Patent Document 2, the detection surface of the sensor is opposed to the detection surface of the encoder 20 so that the rotational speed of the wheel rotating together with the hub 3 can be measured. Then, the measured signal representing the rotational speed of the wheel is used to control a vehicle travel stabilization device such as an anti-lock brake system (ABS) or a traction control system (TCS).

  When the encoder 20 is provided, the encoder 20 is made of a material made of a polymer material having elasticity, such as rubber or synthetic resin mixed with magnetic powder such as ferrite. That is, the material is pressed against one surface of the ring portion 16 of the slinger 13 in a mold in which the slinger 13 to which an adhesive has been applied is previously installed, and is joined to the ring portion 16. As a material for constituting such an encoder 20, generally, a ferrite-containing nitrile rubber is formed into a sheet shape between a pair of rolls, and the ferrite is mechanically oriented. To do. In general, a resol type phenolic resin adhesive is used as the adhesive in consideration of vulcanization adhesion with a rubber magnet. However, in some cases, a phenol resin adhesive mixed with an epoxy resin having high water resistance may be used. Furthermore, these adhesives may be used as top coat adhesives, and silane coupling agents, epoxy resins, etc. may be used as undercoat adhesives (adhesives in multiple layers) to further improve water resistance. In this way, when the encoder 20 is coupled and fixed to the slinger 13, generally, the entire surface of the slinger 13 is covered with a cured adhesive film having a thickness of about several μm. Become.

On the other hand, when it is not necessary to detect the rotational speed of the wheel or when this rotational speed can be detected at another part, an encoder is provided in the slinger 13 as shown in FIG. There is nothing.
In any case, both ends of the annular space 8 are closed over the entire circumference by the seal ring 9 and the combined seal ring 10 to prevent leakage of grease existing in the annular space 8 and externally. It is intended to prevent foreign matters such as moisture and dust existing in the space from entering the annular space 8.

However, when the cylindrical portion 15 of the slinger 13 constituting the combined seal ring 10 is externally fitted and fixed to the end portion of the hub 3, the inner peripheral surface of the cylindrical portion 15 and the outer peripheral surface of the end portion of the hub 3 are fitted. It is not always possible to ensure a sufficient sealing performance for the mating surface. First, in the case of a structure without an encoder as shown in FIG. 7B, the surface of the slinger 13 is in a state where the metal is exposed. For this reason, even when the cylindrical portion 15 of the slinger 13 is externally fitted to the end portion of the hub 3, it is inevitable that a minute gap exists in the fitting portion.
On the other hand, in the case of the structure having the encoder 20 as shown in FIG. 7A, the surface of the slinger 13 is covered with an adhesive film that is a polymer material. When the cylindrical portion 15 of the slinger 13 is externally fitted to the hub 3 by an interference fit, most of the adhesive film existing on the inner peripheral surface of the cylindrical portion 15 is peeled off in the course of the external fitting operation. As a result, as in the case of the structure having no encoder shown in FIG. 7B, a minute gap exists in the fitting portion.
In any case, there is a minute gap in the fitting portion between the inner peripheral surface of the cylindrical portion 15 and the outer peripheral surface of the hub 3, and at least one of the two peripheral surfaces due to moisture that has entered the minute gap. When the peripheral surface of the steel plate corrodes, the minute gap widens, and moisture may enter the annular space 8 through the widened gap. The intrusion of moisture into the annular space 8 is not preferable because it causes a decrease in durability of the rolling bearing unit due to deterioration of grease.

  In view of such circumstances, Patent Documents 3 to 10 describe structures for preventing moisture from entering through a fitting portion between a slinger and a hub. Of these, Patent Documents 3 and 4 describe structures in which the shape of the slinger is a shape that covers the end face of the hub. Patent Documents 5 to 7 describe structures in which an elastic material is interposed between the inner peripheral surface of the cylindrical portion of the slinger and the outer peripheral surface of the hub. Patent Documents 7 to 9 describe a structure in which the inner peripheral edge of a rubber magnet encoder is brought into contact with the outer peripheral surface of a hub or the like over the entire periphery. Further, Patent Document 10 describes a structure in which a fitting portion between the cylindrical portion of the slinger and the hub is covered with an elastic material provided on the slinger separately from the encoder. Note that Patent Document 7 describes the above two structures.

However, the conventional structures described in Patent Documents 3 to 10 as described above have the following problems.
First, in the case of the conventional structures described in Patent Documents 3 and 4, since a slinger having a special shape is used, not only the manufacturing cost of this slinger is increased, but also there is a spatial restriction (installation of the slinger). Not applicable if space is limited).
Further, in the case of the conventional structures described in Patent Documents 5 to 7, since there is a tightening allowance at the fitting portion between the cylindrical portion and the hub, the assemblability is simply reduced based on the presence of the elastic material. However, this elastic material may be peeled off during assembly, and there is a possibility that sufficient sealing performance cannot always be secured. If an O-ring is used as an elastic material, it is possible to prevent deterioration in assemblability and uncertainties in ensuring sealing performance. However, since this O-ring gradually sags, ensuring sufficient sealing performance over a long period of time difficult.

Further, in the case of the conventional structures described in Patent Documents 7 to 9, it is necessary to make the encoder with a magnet material having low elasticity, and the slinger cannot be pushed strongly through the encoder. Therefore, the slinger including this encoder is used as a hub. Workability at the time of external fitting deteriorates. In addition, the inner peripheral edge of the encoder is likely to lack a portion that is in contact with the outer peripheral surface of the hub, and it is difficult to ensure sufficient sealing performance over a long period of time.
Furthermore, in the case of the conventional structure described in Patent Document 10, since an elastic material different from the encoder is provided for the slinger, not only the manufacturing cost increases, but in some cases, the installation space for this elastic material is secured. Can not.
In addition, as publications related to the present invention, there are Patent Documents 11 to 13 in addition to Patent Documents 1 to 10 described above.

JP 2007-85478 A JP 2001-255337 A JP 2006-200708 A JP 2004-316790 A Japanese Patent No. 3963246 JP 2007-163320 A JP 2001-215132 A JP 2002-333035 A JP 2002-206547 A JP 2006-125483 A Japanese Patent No. 3305822 Japanese Patent No. 3036657 JP-A-8-176445

  In view of the circumstances as described above, the present invention can ensure sufficient sealing performance of the fitting portion between the cylindrical portion constituting the slinger and the rotation-side raceway without being restricted by space and for a long period of time. The structure was invented to be realized at low cost.

The rolling bearing unit with a combined seal ring of the present invention is similar to the conventionally known rolling bearing unit with a combined seal ring, and includes a rotating side race ring and a stationary side race ring, a plurality of rolling elements, and a combined seal ring. With.
Of these, the rotation-side raceway and the stationary-side raceway are arranged concentrically with each other.
Further, each of the rolling elements is provided so as to be able to roll between a rotation side track and a stationary side track respectively provided on the circumferential surfaces facing each other of the rotation side raceway and the stationary side raceway.
The combination seal ring closes an end opening of an annular space existing between the circumferential surfaces facing each other of the rotating side raceway and the stationary side raceway and includes a slinger and a seal ring. .
Of these, the slinger is a part of the peripheral surface of the rotating raceway that is fitted and fixed to a portion that faces the peripheral surface of the stationary raceway. The whole is configured in an annular shape. And a cylindrical part, an annular part bent in a radial direction from the axial end edge of the cylindrical part toward the stationary side ring, and a cross-sectional arc existing in a continuous part of the cylindrical part and the annular part It consists of a curved surface part.
Further, the seal ring is a part of the stationary side race ring that is fitted and fixed to a portion facing the slinger, and a core metal that is fitted and fixed to the stationary side race ring. And a plurality of seal lips supported on the respective base ends. And the front-end | tip part of each of these seal lips is slidably contacted with the surface of the said slinger over the perimeter.

In particular, in the rolling bearing unit with a combined seal ring according to the present invention, an adhesive (sealing) having oil level adhesion in a gap existing between the curved surface portion of the slinger and the peripheral surface of the rotating raceway. Agent) is filled over the entire circumference. As such an adhesive, for example, as in the invention described in claim 2, the main component is at least one selected from an epoxy resin, a urethane-modified acrylate, and a silicon resin.
When implementing the combination seal ring of the present invention as described above, for example, as described in claim 3, on both sides of the annular part constituting the slinger, on the side opposite to the cylindrical part, A ring-shaped encoder made of a permanent magnet and having S poles and N poles alternately arranged on the side surfaces is fixedly attached over the entire circumference. Then, in addition to the gap existing between the curved surface portion of the slinger and the peripheral surface of the rotating raceway, the peripheral surface of the rotating raceway and the peripheral edge of the encoder are added to the adhesive having the oil surface adhesiveness. Fill the entire circumference between and.
When carrying out the invention as described in claim 3, the permanent magnet constituting the encoder is contained in the thermoplastic resin as in the invention described in claim 4, for example. A plastic magnet is used.

According to the rolling bearing unit with a combined seal ring of the present invention as described above, the sealing performance of the fitting portion between the cylindrical portion constituting the slinger and the rotating side raceway ring is not subject to spatial restrictions and is long. A structure that can be sufficiently planned over a period can be realized at low cost.
That is, in the case of the present invention, the gap between the curved surface portion of the slinger and the peripheral surface of the rotating raceway is filled with an adhesive having oil surface adhesion over the entire periphery. Therefore, foreign matter such as moisture does not enter the fitting portion between the cylindrical portion of the slinger and the rotating raceway. In addition, since the adhesive is almost contained in the gap and does not occupy an extra space, there is almost no spatial restriction on the structure for ensuring the sealing property. Furthermore, since the adhesive filled in the gap is not particularly stressed from the outside, it is less likely to be deteriorated by long-term use, and the sealing property of the fitting portion is maintained for a long time. it can.

[First example of embodiment]
1 and 2 show a first example of an embodiment of the present invention corresponding to claims 1 to 4. In the case of this example, the inner ring 22 that is the rotation side raceway is arranged concentrically with the inner diameter side of the outer ring 21 that is the rotation side raceway. And it is a rolling element between the outer ring track 23 which is a stationary side track formed on the inner peripheral surface of the outer ring 21 and the inner ring track 24 which is a rotation side track formed on the outer peripheral surface of the inner ring 22. A plurality of balls 6 are provided so as to be able to roll while being held by the cage 7a. Further, an end opening of an annular space 25 that is located between the inner peripheral surface of the outer ring 21 and the outer peripheral surface of the inner ring 22 and in which the balls 6 are installed is closed by a combination seal ring 10a.

  This combination seal ring 10a includes a slinger 13a and a seal ring 14a. Of these, the slinger 13a is externally fixed to the outer peripheral surface of the end portion of the inner ring 22 by an interference fit, and is formed into an annular shape with an L-shaped cross section by bending a metal plate. . That is, the slinger 13a includes a cylindrical portion 15a provided on the inner peripheral edge, an annular portion 16a bent at a right angle outward from the axial end edge of the cylindrical portion 15a, and a shaft of the cylindrical portion 15a. It consists of a curved surface portion 17a having a circular arc cross section existing at a continuous portion between the direction end edge and the inner peripheral edge of the ring portion 16a. The seal ring 14a is fixed to the inner peripheral surface of the end portion of the outer ring 21 by an interference fit, and a metal core having an approximately L-shaped cross section and an annular shape as a whole by bending a metal plate. 18a and a plurality of seal lips 19a, 19a made of an elastic material. The seal ring 14a has a cylindrical portion 26 provided on the outer peripheral edge of the cored bar 18a fitted to the inner peripheral surface of the end portion of the outer ring 21 with an interference fit, and the distal ends of the seal lips 19a and 19a are fitted. The slinger 13a is slidably contacted with the outer peripheral surface of the cylindrical portion 15a and one side surface of the annular ring portion 16a.

Further, of the both side surfaces in the axial direction of the ring portion 16a of the slinger 13a, the surface opposite to the surface where the seal lips 19a, 19a are slidably contacted (the right side surface in FIGS. An annular encoder 20a made of magnet is attached and fixed over the entire circumference. The encoder 20a is magnetized in the axial direction, and the magnetization direction is changed alternately and at equal intervals in the circumferential direction. Therefore, S poles and N poles are alternately arranged at equal pitches on the side surface of the encoder 20a. The number of poles on the side surface of the encoder 20a is about 70 to 130, preferably 90 to 120. When the number of poles is less than 70, the number of poles is so small that it is difficult to obtain the rotational speed of the inner ring 22 in real time. On the other hand, when the number of poles exceeds 130 poles, the pitch between the adjacent S poles and N poles becomes too small, making it difficult to suppress the pitch error, and the rotational speed of the inner ring 22 can be accurately controlled. It becomes difficult to ask.
Further, in the case of the rolling bearing unit with the combined seal ring of this example, a gap exists between the inner peripheral surface of the curved surface portion 17a of the slinger 13a and the inner peripheral edge of the encoder 20a and the outer peripheral surface of the inner ring 22. 27 is filled with an adhesive 28 having oil surface adhesion over the entire circumference.

According to the rolling bearing unit with a combined seal ring of this example as described above, ensuring the sealing performance of the fitting portion between the cylindrical portion 15a constituting the slinger 13a and the inner ring 22 is not subject to spatial restrictions, In addition, a structure that can be sufficiently achieved over a long period of time can be realized at low cost.
That is, in the case of the rolling bearing unit with the combined seal ring of this example, the clearance existing between the inner peripheral surface of the curved surface portion 17a of the slinger 13a, the inner peripheral edge of the encoder 20a, and the outer peripheral surface of the inner ring 22. 27 is filled with an adhesive 28 having oil surface adhesion over the entire circumference, so that moisture or the like is applied to the fitting portion between the inner peripheral surface of the cylindrical portion 15a and the outer peripheral surface of the inner ring 22. No foreign material enters. In addition, the adhesive 28 is almost contained in the gap 27 and does not occupy an extra space, so that there is almost no space restriction on the structure for ensuring the sealing property. Further, the adhesive 28 filled in the gap 27 is not particularly subjected to stress or the like from the outside. That is, the adhesive 28 is strongly compressed as the cylindrical portion 15a and the inner ring 22 are fitted, or a bending force or the like is applied to the adhesive 28 when a rolling bearing unit with a seal ring is used. There is nothing. For this reason, the adhesive 28 is hardly deteriorated by long-term use, and the sealing property of the fitting portion between the inner peripheral surface of the cylindrical portion 15a and the outer peripheral surface of the inner ring 22 is maintained over a long period. it can.

Next, including the structure of this example, a description will be given of suitable materials and the like together with the reason why the materials and the like are necessary when the rolling bearing unit with a combined seal ring of the present invention is implemented.
First, the adhesive (sealing agent) 28 having oil surface adhesiveness will be described. Since the bearing rings such as the outer ring 21 and the inner ring 22 constituting the rolling bearing unit are formed of bearing steel having poor corrosion resistance such as SUJ2, the above combination is maintained with the oil-based rust preventive applied on the surface. It is assembled as a rolling bearing unit with a seal ring. Therefore, the adhesive 28 filled in the gap 27 needs to be cured in a state in which the oil component of the rust preventive agent is taken in and be in an adhesive state with the surface covered with the oil component.

As the adhesive 28 having oil surface adhesiveness that satisfies such conditions, an adhesive mainly composed of at least one selected from silicon compounds (silicone rubber) such as urethane-modified acrylate, epoxy resin, and silicon resin can be used. It is.
Among these, as the oil surface adhesive mainly composed of urethane-modified acrylate, for example, those described in Patent Document 11 can be used. This oil surface adhesive is characterized in that it contains a urethane-modified acrylate having a polybutylene glycol structure which is a polyol component in the molecular structure in order to develop oil surface adhesion. This urethane-modified acrylate is composed of isophorone diisocyanate (IPDI), tolylene diisocyanate (TDI), etc. as isocyanate components, and 2-hydroxyethyl methacrylate (2HEMA), 2-hydroxyethyl acrylate (2HEA), etc. as acrylate components. It is configured to include. Such oil surface adhesives mainly composed of urethane-modified acrylates include acrylic monomers such as methoxydiethylene glycol methacrylate, curing agents such as peroxides, and fillers such as silica, in addition to the main component urethane-modified acrylates. Etc. are contained.
Moreover, as an oil surface adhesive which has an epoxy resin as a main component, what was described in patent document 12, for example can be used. This oil surface adhesive mainly contains an epoxy prepolymer containing a modified epoxy compound modified with a diene liquid rubber having a terminal carboxyl group, and contains other components such as a urethane prepolymer and a latent curing agent. There is.
Furthermore, as an oil surface adhesive mainly composed of a silicon compound, for example, the one described in Patent Document 13 can be used. Some of the oil surface adhesives contain diorganopolysiloxane having hydroxyl groups at both ends, iminoxysilane, organotin catalyst, oil-absorbing carbon powder, silane-modified polyoxyalkylene, or polyether-modified polysiloxane.

Next, the material constituting the permanent magnet which is the encoder 20a, and a method of forming the encoder 20a while joining the encoder 20a and the slinger 13a will be described.
The material constituting the encoder 20a is not particularly limited, but considering the bondability to the slinger 13a, a magnetic compound containing about 50 to 80% by volume of magnetic powder and using a thermoplastic resin or rubber as a binder is used. It is preferable to do. Among these, ferrites such as strontium ferrite and barium ferrite, and rare earth magnetic powders such as neodymium-iron-boron, samarium-cobalt, and samarium-iron can be used as the magnetic powder. Furthermore, in order to improve the magnetic properties of ferrite, a material mixed with a rare earth element such as lanthanum can be used. Regardless of which magnetic powder is used, if the content of the magnetic powder is less than 50% by volume, the magnetic properties are inferior and it is difficult to perform multipolar magnetization in the circumferential direction at a fine pitch. On the other hand, when the content of the magnetic powder exceeds 80% by volume, the amount of the binder becomes too small, the strength of the encoder 20a as a permanent magnet is lowered, and at the same time, molding becomes difficult. For this reason, it is preferable to regulate the content of the magnetic powder in the range of 50 to 80% by volume.

  In addition, when using a thermoplastic resin as said binder, what can be injection-molded is suitable. Specifically, polyamide 6, polyamide 12, polyamide 612, polyamide 11, polyphenylene sulfide (PPS), modified polyamide 12 comprising a hard segment comprising polyamide 12 and a soft segment comprising a polyether chain or a polyester chain, polybutylene terephthalate Further, a modified polyester composed of a hard segment composed of polyester such as polybutylene naphthalate and a soft segment composed of a polyether chain or a polyester chain can be used. When the rolling bearing unit with a seal ring is for supporting automobile wheels, calcium chloride used as a snow melting agent may adhere to the encoder 20a together with water. Therefore, it is more preferable to use polyamide 12, polyamide 612, polyamide 11, polyphenylene sulfide, modified polyamide 12, or modified polyester having a low water absorption as the binder.

Furthermore, as a binder for preventing cracking due to a sudden temperature change (thermal shock) assumed in the environment of use of the encoder 20a, the modified polyamide 12, which improves bending flexibility and crack resistance, Most preferred is a modified polyester, a mixture of modified polyamide 12 and polyamide 12, or a mixture of modified polyester and polyester resin.
On the other hand, when rubber is used as the binder, nitrile rubber, acrylic rubber, hydrogenated nitrile rubber, fluororubber, etc. having both oil resistance and heat resistance are suitable.
In consideration of the manufacturing cost and oxidation resistance of the encoder 20a, a ferrite type is most suitable as the magnetic powder. On the other hand, when using rare earths, which give priority to magnetic properties and have lower oxidation resistance than ferrites, the surface of the exposed permanent magnet is used to maintain stable magnetic properties over a long period of time. In addition, a surface treatment layer may be provided. Specifically, as the surface treatment layer in this case, electric or electroless nickel plating, an epoxy resin coating film, a silicon resin coating film, a fluorine resin coating film, or the like can be used.

On the other hand, the material of the slinger 13a is preferably a metal plate that does not deteriorate the magnetic properties of the permanent magnet material constituting the encoder 20a and has a certain degree of corrosion resistance depending on the use environment. Specifically, in addition to ferritic stainless steel sheets such as SUS430, martensitic stainless steel sheets such as SUS410, and the like, high corrosion resistance ferritic stainless steels such as SUS434 and SUS444 that are further improved by adding Mo or the like to these. A magnetic material such as a steel plate is suitable.
Further, the side surface of the ring portion 16a of the slinger 13a and the joint surface of the encoder 20a are made of an adhesive for joining the ring portion 16a and the encoder 20a (adhesive different from the oil surface adhesive). In order to improve the bonding force due to (), it is preferable to provide fine irregularities. As a method for providing unevenness for such purposes, mechanical etching such as shot blasting or transfer of unevenness on the mold surface during press molding, or chemically etching the surface once surface-treated with acid or the like You can also adopt the method. In any case, if fine irregularities are provided on the side surface of the annular portion 16a where the encoder 20a is to be joined, the adhesive enters the irregularities, and the anchor effect causes the annular portion 16a and The joining force with the permanent magnet material constituting the encoder 20a becomes strong, which is preferable.

  An adhesive for joining the annular portion 16a and the encoder 20a is previously applied to the surface of the annular portion 16a. Then, in a state where the slinger 13a is installed in a cavity of a mold for injection molding the encoder 20a, insert molding is performed in which a permanent magnet material for forming the encoder 20a is fed into the cavity. At the time of the insert molding, the adhesive is in a semi-cured state to such an extent that it does not flow away from the annular portion 16a due to a molten high-pressure plastic magnet material or rubber magnet material. And it will be in a completely hardened state by the heat from molten resin or fluid rubber, and also by the secondary heating after molding in addition to this heat. Such an adhesive for joining the ring portion 16a and the encoder 20a can be diluted with a solvent, and a phenolic resin-based adhesive or an epoxy resin-based adhesive that progresses in almost two stages. An adhesive or the like can be preferably used when heat resistance, chemical resistance, and handling properties are taken into consideration.

  In any case, the injection molding of the encoder 20a is preferably performed by a disk gate method or a ring gate method similar to the disk gate method. When the injection molding of the encoder 20a is performed by these methods, for example, when the permanent magnet material is a plastic magnet having a thermoplastic plastic as a binder, a thick portion (inner diameter or outer diameter) is formed during the injection molding of the encoder 20a. The molten high-pressure plastic magnet material, which is simultaneously fed over the entire circumference from the peripheral edge or the outer peripheral edge) into the mold cavity, is rapidly cooled and solidified in the cavity. When the injection molding of the encoder 20a is performed by the above method, the plastic magnet material (molten resin) fed into the cavity spreads in a disk shape and corresponds to the inner or outer peripheral edge of the encoder 20a after completion. It flows into the cavity from the part that does. For this reason, the flake-like magnetic powder contained in the plastic magnet material is oriented in parallel to both axial sides of the encoder 20a. In particular, in the encoder 20a, the orientation of the intermediate portion in the radial direction facing the detection unit of the rotation sensor is high, and the state becomes very close to the axial anisotropy oriented in the thickness direction.

  Further, if the encoder 20a is molded in a state in which a magnetic field is applied to the mold in the thickness direction of the encoder 20a, the anisotropy can be made closer to perfection. In this way, even when the encoder 20a is injection-molded while applying a magnetic field to the mold, so-called magnetic field molding is performed, a gate for feeding the plastic magnet material into the cavity is not a disk gate, for example, a pin gate. In this case, it is difficult to make the orientation of the magnetic powder completely anisotropic. This is because the direction of the magnetic powder is determined in the process in which the plastic magnet material fed into the cavity from the pin gate moves in the cavity and gradually increases in viscosity toward solidification, This is because it is very difficult to regulate the direction of the magnetic powder at the weld portion, which is a butt portion of the plastic magnet materials that have advanced from different directions. If the direction of the magnetic powder cannot be sufficiently anisotropic, the magnetic characteristics of the obtained encoder 20a are deteriorated. Further, since a weld portion having a low mechanical strength appears, damage such as a crack is likely to occur in a part of the encoder 20a due to long-term use. For this reason, it is not preferable to perform the injection molding of the encoder 20a by a method other than the disk gate method and the ring gate method.

  Even when the permanent magnet material constituting the encoder 20a is a rubber magnet, when the encoder 20a is manufactured by injection molding, it is performed by the disk gate method or the ring gate method as in the case of the plastic magnet described above. Is preferred. On the other hand, if the compression molding is performed, an unvulcanized rubber magnet material formed into a sheet shape with the slinger 13a installed in the molding die (lower mold) is formed into a ring of the slinger 13a. It is placed on the portion 16a, and another rubber mold (upper mold) is put on the rubber magnet material, and vulcanization adhesion is performed while heating. Simultaneously with the molding of the encoder 20a, the encoder 20a and the slinger 13a. The annular portion 16a is joined.

[Second Example of Embodiment]
FIGS. 3-4 has shown the 2nd example of embodiment of this invention corresponding to Claim 1,2. Also in the case of this example, the cylindrical portion 15b of the slinger 13b is externally fitted and fixed to the outer peripheral surface of the end portion of the inner ring 22a that is the rotation side raceway. In particular, in the case of this example, after the metal plate constituting the slinger 13b is turned 180 degrees radially inward from the outer peripheral edge portion of the annular ring portion 16b, the metal plate is formed at the radial intermediate portion of the annular ring portion 16b. The support cylindrical portion 29 is bent 90 degrees on the opposite side to the cylindrical portion 15b. A cylindrical encoder 20b is formed on the outer peripheral surface of the support cylindrical portion 29 over the entire circumference. The encoder 20b made of a permanent magnet is magnetized in the radial direction, and the magnetization direction changes alternately and at equal intervals in the circumferential direction. Accordingly, the S pole and the N pole are alternately arranged at equal intervals in the circumferential direction on the outer peripheral surface of the encoder 20b. As shown in FIG. 4, the boundary between the S pole and the N pole adjacent in the circumferential direction is inclined with respect to the axial direction.

On the other hand, in addition to the seal ring 14a, the sensor unit 30 is supported and fixed on the inner peripheral surface of the end portion of the outer ring 21a which is a stationary side race. The sensor unit 30 holds a pair of sensor elements 31, 31 in a state of being separated in the axial direction of the outer ring 21a. These two sensor elements 31 and 31 are placed close to and opposed to the outer peripheral surface of the encoder 20b. In the case of such a structure of this example, the phase difference between the detection signals of the two sensor elements 31 and 31 that is generated when an axial load is applied between the inner ring 22a and the outer ring 21a. Based on this, the axial load can be measured. In the case of such a structure of this example, among the metal plates constituting the slinger 13b, the inner peripheral surface of the curved surface portion 17b existing between the cylindrical portion 15b and the circular ring portion 16b and the inner ring 22a. The adhesive 28 having oil surface adhesiveness is filled over the entire circumference.
The configuration and operation of the other parts are the same as in the case of the first example of the embodiment described above.

[Third example of embodiment]
FIG. 5 shows a third example of an embodiment of the present invention corresponding to claims 1 and 2. In the case of this example, the encoder 20a (see FIGS. 1 and 2) is omitted from the first example of the embodiment described above. Along with this, the adhesive 28 having oil surface adhesion is applied to the inner peripheral surface 22 and the inner ring 22 of the curved surface portion 17a existing between the cylindrical portion 15a and the ring portion 16a of the metal plate constituting the slinger 13a. Only the gap 27 between the outer circumferential surface and the outer circumferential surface is filled over the entire circumference.
The configuration and operation of the other parts are the same as in the case of the first example of the embodiment described above.

An example of the implementation of the present invention will be described below. This example is suitable for obtaining the structure of the first example of the embodiment described above.
Permanent magnet material for constituting encoder: Strontium ferrite containing 12 nylon-based anisotropic plastic magnet compound manufactured by Toda Kogyo Co., Ltd., trade name “FEROTOP TP-A27N”
Content of the above strontium ferrite: 75% by volume
Maximum energy product by magnetic field shaping: 2.1 MGOe
Encoder manufacturing method: Applying a magnetic field in the thickness direction (axial direction) of the permanent magnet material that will be the encoder, molding by the disk gate method → reverse demagnetization when cooling in the mold, Complete demagnetization → This permanent magnet material is magnetized to 96 poles with a total circumference of S and N poles by magnetizing yoke → To completely cure the adhesive that joins the encoder and slinger Heated at 150 ° C for 1 hour. Thickness of the encoder in the axial direction: 0.9mm

The specifications of slinger and adhesive are as follows.
Slinger thickness: 0.6mm
Slinger material: SUS430
Slinger surface finish: No. 2B finish (surface roughness = about 0.06Ra)
Of the slinger, the surface roughness of the side surface of the circular ring part to which the encoder is joined: 1.3 Ra (by shot blasting)
Adhesive for joining slinger and encoder and its application method: Phenol resin adhesive with a solid content of 30% by weight based on a novolac type phenolic resin (trade name “Metaloc N-” manufactured by Toyo Chemical Laboratory Co., Ltd.) 15 ”) is diluted 3 times with methyl ethyl ketone, applied to the surface of slinger by dipping treatment → dried at room temperature for 30 minutes, and then left in a drier at 120 ° C. for 30 minutes to obtain a semi-cured state.
Type of oil surface adhesive and filling method thereof: A two-component oil surface adhesive (made by Denki Kagaku Kogyo Co., Ltd., trade name “DENKA HARDLOCK 2”) mainly composed of urethane-modified acrylate, After filling the gap between the inner peripheral surface of the curved surface portion and the outer peripheral surface of the inner ring, it is left to cure at room temperature.

  The present invention is not limited to a rolling bearing unit for supporting a wheel of an automobile, but is used in an environment where corrosive foreign matters such as moisture may adhere to a fitting portion between a slinger and a rotating raceway. The present invention can be applied to a rolling bearing unit with a combined seal ring incorporated in a rotation support portion of a mechanical device. Further, the present invention can be applied not only to the inner ring rotation type rolling bearing unit but also to the outer ring rotation type rolling bearing unit.

The fragmentary sectional view which shows the 1st example of embodiment of this invention. The A section enlarged view of FIG. The fragmentary sectional view which shows the 2nd example of embodiment of this invention. The perspective view of the encoder integrated in this 2nd example. The fragmentary sectional view which shows the 3rd example of embodiment of this invention. Sectional drawing which shows an example of a conventional structure. The B section enlarged view of FIG. 6 which shows two examples of the structure of a combination seal ring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rolling bearing unit 2 Outer ring 3 Hub 4 Outer ring raceway 5 Inner ring raceway 6 Ball 7, 7a Cage 8 Annular space 9 Seal ring 10, 10a Combination seal ring 11 Core metal 12 Seal lip 13, 13a, 13b Slinger 14, 14a Seal ring 15, 15a, 15b Cylindrical part 16, 16a, 16b Circular ring part 17, 17a, 17b Curved part 18, 18a Core metal 19, 19a Seal lip 20, 20a, 20b Encoder 21, 21a Outer ring 22, 22a Inner ring 23 Outer ring raceway 24 Inner ring raceway 25 Annular space 26 Cylindrical portion 27 Gap 28 Adhesive 29 Supporting cylindrical portion 30 Sensor unit 31 Sensor element

Claims (4)

  The rotating side raceway and the stationary side raceway arranged concentrically with each other, and the rotation side raceway and the stationary side raceway between the rotation side raceway and the stationary side raceway respectively provided on the mutually opposing circumferential surfaces. A plurality of rolling elements provided in a freely movable manner, and a slinger and a seal ring for closing an end opening of an annular space existing between mutually opposing circumferential surfaces of the rotating side raceway and the stationary side raceway The slinger is a part of the peripheral surface of the rotating side race ring and is fitted and fixed to a portion facing the peripheral surface of the stationary side race ring. By bending the plate, the whole is formed into an annular shape with an L-shaped cross section, a cylindrical portion, and an annular portion bent radially from the axial end edge of the cylindrical portion toward the stationary raceway, The disconnection existing in the continuous part between the cylindrical part and the annular part. An arc-shaped curved surface portion, and the seal ring is fitted and fixed to a part of the stationary side race ring facing the slinger, and is fitted and fixed to the stationary side race ring. A combination in which a metal core and a plurality of seal lips each of which has a base end supported by the metal core are provided, and the tip of each seal lip is in sliding contact with the surface of the slinger over the entire circumference. In a rolling bearing unit with a seal ring, the gap between the curved surface of the slinger and the peripheral surface of the rotating raceway is filled with an adhesive having oil level adhesion over the entire circumference. A rolling bearing unit with a combined seal ring characterized by   The rolling bearing unit with a combined seal ring according to claim 1, wherein the adhesive having oil surface adhesion is mainly composed of at least one selected from an epoxy resin, a urethane-modified acrylate, and a silicon resin. .   An annular encoder made of a permanent magnet on the opposite side of the circular ring part constituting the slinger and having S poles and N poles alternately arranged on the side faces In addition to the gap existing between the curved surface portion of the slinger and the peripheral surface of the rotating side raceway, an adhesive having oil surface adhesion is fixed to the peripheral surface of the rotating side raceway. The rolling bearing unit with a combined seal ring according to any one of claims 1 to 2, wherein the entire circumference is also filled between the periphery of the encoder.   The rolling bearing unit with a combined seal ring according to claim 3, wherein the permanent magnet constituting the encoder is a plastic magnet in which magnetic powder is contained in a thermoplastic resin.

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