JP2008274995A - Bearing sealing device and wheel supporting bearing unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bearing sealing device having sealing construction superior in durability for retaining constant sealing performance over a long period, and to provide a wheel supporting bearing unit. <P>SOLUTION: The bearing sealing device 2 is provided for sealing a bearing device A which has bearing rings 10, 12 and a plurality of rolling elements 18. It comprises a slinger 22, a core metal 24 and a seal 26 combined to form a sectional contour in an approximately rectangular shape. The slinger consists of a cylindrical slinger fixed part 22a to be fixed to one bearing ring, and a slinger disc part 22b continuously ranging from the one-side extension end of the slinger fixed part. The core metal consists of a cylindrical core metal fixed part 24a to be fixed to the other bearing ring, and a core metal disc part 24b continuously ranging from the one-side extension end of the core metal fixed part. The seal is laid between the slinger and the core metal, and connected to one of them and put in slide contact with the other. Electropainting is applied to at least the slinger fixed part of the slinger. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sealing structure for keeping the inside of various bearings (for example, a bearing device such as a hub unit bearing (wheel supporting bearing unit) for supporting a wheel of an automobile) in a sealed state. The present invention relates to an improvement in a sealing structure for improving the sealing performance of a wheel support bearing unit.

  Conventionally, the bearing device has been provided with various sealing devices in order to shield the inside of the bearing from the outside and keep it in a sealed state (airtight state and liquid tight state), and by providing the sealing device, Prevents foreign matter (e.g., muddy water, dust, etc.) from entering the bearing device from the outside, and prevents lubricant (e.g., grease, lubricating oil, etc.) enclosed inside from leaking to the outside. It is preventing.

  Such a sealing device can be roughly classified into a contact type and a non-contact type. For example, as the contact type, an annular core formed by press working or the like such that a cross-section of the steel plate is formed in an L shape. There is a seal that has a structure in which various elastic materials (for example, resin materials such as rubber and plastic) are connected to a part of gold, and as a non-contact type, it is pressed from a metal plate (steel plate) such as stainless steel plate There is a shield molded by processing. Furthermore, a contact-type sealing device (so-called pack seal) having a package structure obtained by combining the contact-type seal and the non-contact-type shield (so-called slinger) so that the cross-sectional shape is substantially box-shaped (rectangular) is also known. (See Patent Document 1).

  In general, the contact type has higher sealing performance than the non-contact type, and depending on the level of hermeticity (air tightness and liquid tightness) required according to the usage conditions and purpose of the bearing device Different sealing devices are used.

  As an example, the pack seal has not only the feature that the cross-sectional area is small and compact, and it is not necessary to secure a large installation space, but also an excellent feature that the sealing performance is extremely high and the torque is low. Therefore, a bearing device that requires a strict sealing performance (for example, a high level of muddy water invasion preventing effect), for example, a hub unit bearing (hereinafter referred to as a bearing unit) for supporting a vehicle wheel as shown in FIG. It is widely used as a sealing device for A).

FIG. 2 shows a configuration example of such a pack seal. The pack seal 2 includes a slinger 22 and a cored bar (hereinafter referred to as a seal cored bar) 24 which are arranged to face each other at a predetermined interval. The seal 26 is interposed between them. In this case, the slinger 22 and the seal core 24 are both formed in an annular shape having a substantially L-shaped cross section, and the seal 26 is connected to the seal core 24 and is slid on the slinger 22. A plurality of lip portions 26l that are in contact with each other are provided.
In manufacturing the pack seal 2 having such a configuration, the slinger 22 and the seal core 24 are usually formed by pressing a thin steel plate or the like in consideration of ease of processing and cost. Yes.

  When the pack seal 2 having such a configuration is assembled to the bearing unit A (FIG. 1A), the slinger 22 is fixed (specifically, to the rotating wheel 10 (specifically, the inner ring component 16). The seal metal core 24 is fixed (specifically, fitted) to the stationary wheel 12 and is always stationary, while being rotated together with the rotating wheel 10 (inner ring component 16). Maintained.

By the way, as described above, the pack seal 2 has a feature that it is very compact, but is compact (that is, has a small cross-sectional area), so that the rotary wheel 10 (inner ring configuration) when assembled to the bearing unit A is used. The fitting length between the body 16) and the stationary wheel 12 (the length in the axial direction (left-right direction in FIG. 2)) becomes short, and the fitting force may not be sufficiently secured.
For this reason, metal fitting is performed when the pack seal 2 is assembled to the bearing unit A so that a sufficient fitting force can be obtained even when the fitting length is short.

However, when the pack seal 2 is assembled to the bearing unit A by metal fitting, when the slinger 22 is press-fitted into the rotating wheel 10 (inner ring component 16) and when the seal metal core 24 is press-fitted into the stationary wheel 12. In addition, there is a risk that scratches in the axial direction (left-right direction in FIG. 2) may occur on the fitting surfaces 22s and 24s. Similarly, there is a possibility that scratches in the axial direction may occur on the fitting surface of the rotating wheel 10 (inner ring structure 16) and the fitting surface of the stationary wheel 12.
When the slinger 22 and the seal metal core 24 are formed by the press work as described above, axial flaws (streaks) are generated on the fitting surfaces 22s and 24s by the press machine during the forming. Sometimes it ends up.

  When such axial flaws occur on the fitting surfaces 22s, 24s of the slinger 22 and the seal metal core 24 or the fitting surfaces of the rotating wheel 10 (inner ring component 16) and the stationary wheel 12, bearings There is a case where water enters the damaged part from the outside of the unit A, and for example, the fitting surface of the rotating wheel 10 (inner ring structure 16) or the stationary wheel 12 may rust. If the fitting surfaces of the rotating wheel 10 (inner ring structure 16) and the stationary wheel 12 rust in this manner, the fitting force with the slinger 22 and the seal metal core 24 is reduced, and the sealing performance thereof (infiltration prevention effect). This also reduces the amount of water entering the bearing unit A from the fitting portion between the slinger 22 and the rotating wheel 10 (inner ring structure 16) or the fitting portion between the seal metal core 24 and the stationary ring 12. There is a risk of it.

In order to avoid such inconveniences, various measures have been taken conventionally.For example, a seal is connected to the outer diameter portion (end portion of the fitting surface) of the seal metal core (for example, vulcanization molding). However, a method for forming a rubber nose gasket is known. On the other hand, since the slinger 22 is often not vulcanized and a rubber nose gasket cannot be formed like a seal core, a rubber sealant is applied to the inner diameter portion (fitting surface). Measures to apply such as painting are known.
JP 2001-215132 A

  However, in these measures, the quality of coating with the nose gasket and the sealing material to be formed tends to become unstable, and the cost for performing these processes becomes necessary. In addition, when the slinger 22 is press-fitted into the rotating wheel 10 (inner ring structure 16), the coating applied to the inner diameter portion (fitting surface) is easily peeled off, and as a result, sufficient sealing performance (infiltration prevention effect) can be obtained. May become impossible.

  The present invention has been made to solve such a problem, and the object thereof is to provide a bearing sealing device having a durable sealing structure capable of maintaining a constant sealing performance for a long period of time, And providing a wheel supporting bearing unit.

  In order to achieve such an object, a bearing sealing device according to the present invention includes at least a pair of bearing rings opposed to each other so as to be relatively rotatable, and a plurality of rolling rings incorporated so as to be able to roll between the bearing rings. In order to keep the inside of the bearing device including the moving body airtight and liquid-tight, the slinger, the cored bar, and the seal are combined so that the profile of the cross section becomes a substantially rectangular shape. In such a bearing sealing device, the slinger has a cylindrical shape extending in a predetermined direction, and is continuous with a slinger fixing portion fixed to the one race ring, and an extension end on one side of the slinger fixing portion. The slinger disk portion extends at a predetermined angle with respect to the slinger fixing portion, and the cored bar has a cylindrical shape extending in a predetermined direction and is fixed to the other race ring. Consists of a mandrel fixing part and a mandrel disk part that is continuous to one end of the mandrel fixing part and extends at a predetermined angle with respect to the mandrel fixing part. Is interposed between the slinger and the cored bar, which are opposed to each other, and is connected to one of the slinger and the cored bar and is in sliding contact with the other, and the slinger has at least a slinger fixing part. On the other hand, electrodeposition coating is applied.

  In this case, as an example, the bearing sealing device has a structure in which the slinger and the metal core are made of metal and the seal is connected to the slinger and the metal core by vulcanization molding.

  In the bearing sealing device as described above, for example, a stationary wheel fixed to a vehicle body component member and a rotating wheel fixed to the wheel component member and rotating together with the wheel component member are opposed to each other so as to be relatively rotatable. And a plurality of rolling elements that are formed on the stationary ring and the rotating ring, respectively, and are incorporated so as to be able to roll between the raceways facing each other. It can be applied as a sealing device for keeping liquid-tight.

  In addition, the wheel support bearing unit according to the present invention includes a stationary wheel fixed to a vehicle body constituent member and a rotating wheel to which the wheel constituent member is fixed and rotates together with the wheel constituent member so as to be relatively rotatable. A raceway ring, a plurality of rolling elements formed on the stationary ring and the rotary wheel, respectively, and incorporated so as to roll between raceways facing each other, and a sealing device for keeping the inside airtight and liquid tight is doing. In such a wheel support bearing unit, the sealing device includes a slinger fixed to the rotating wheel, a core metal fixed to the stationary wheel, and the slinger and the metal core facing each other at a predetermined interval. The seal is interposed and connected to one of the slinger and the metal core, and has a seal that is slidably in contact with the other. The slinger, the metal core, and the seal are combined so that the profile of the cross section is substantially rectangular. The rotating wheel is subjected to electrodeposition coating on at least a fixed portion of the surface with the slinger.

  According to the present invention, by applying electrodeposition coating (so-called cation coating) to the slinger or the rotating wheel (inner ring constituent body), it is possible to maintain a certain sealing performance for a long time and to have excellent durability. It is possible to provide a bearing sealing device and a wheel-supporting bearing unit having a structure.

Hereinafter, a bearing sealing device (hereinafter also simply referred to as a sealing device) and a wheel support bearing unit (hereinafter also simply referred to as a bearing unit) according to the present invention will be described with reference to the accompanying drawings. The bearing sealing device according to the present invention can be applied as a sealing device for sealing the inside of various bearing devices, but here, the wheel of an automobile as shown in FIG. 1 (a) is supported. For example, a case where such a sealing device is used to seal the inside of a hub unit bearing (bearing unit A) is assumed. In this case, the basic configuration of the sealing device according to the present invention is the same as that of the above-described conventional sealing device (FIG. 2), and the same components are denoted by the same reference numerals in the drawing.
Here, it is assumed as an example that such a sealing device is disposed on the vehicle body side (the right side in FIG. 1A) of an automobile not shown. Here, in the following description, the inner side of the vehicle body (not shown) on which the sealing device is disposed is referred to as the inboard side, and the opposite side, that is, the wheel side of the vehicle (not shown) (left side in FIG. 1A). Is called the outboard side.

  FIG. 1 (a) shows the driving wheels of an automobile (rear wheels of a front engine rear wheel drive (FR) car and rear engine rear wheel drive (RR) car, front engine front wheel drive (FF) car). The configuration of a hub unit bearing that supports front wheels and all wheels of a four-wheel drive (4WD) vehicle is shown as an example, but the bearing unit is a driven wheel of an automobile (a front wheel of an FR car and an RR car, an FF car) You may comprise as a hub unit bearing which supports a rear wheel.

  The type (type) of the bearing unit is not particularly limited. For example, the presence / absence and number of the flanges 14f of the rotating wheel 10 (hub 14), the presence / absence and number of the flanges 12f of the stationary ring 12, or the presence / absence of the inner ring component 16 The type of rolling element 18 (balls and various rollers) may be arbitrarily set according to the usage conditions and purpose of the bearing unit. Further, in the configuration shown in FIG. 1 (a), the outer member (outer raceway) is a stationary ring 12, and the inner member (inner raceway) is a rotating wheel 10 (hub 14 and inner ring component 16). However, on the contrary, a bearing unit having a configuration in which the outer member (outer race ring) is a rotating ring and the inner member (inner race ring) is a stationary ring may be used.

The inner ring constituting body 16 is formed with a raceway surface 10t facing the raceway surface 12t on the inboard side of the stationary wheel 12 and is fitted on the inboard side of the hub 14 to constitute the rotating wheel 10 together with the hub 14. It refers to a member.
Also, in any bearing unit, the rotating wheel 10 has a wheel constituent member (for example, a disc wheel (not shown)) fixed and rotated together with the wheel constituent member, whereas the stationary wheel 12 It is fixed to a structural member (for example, a knuckle (not shown) of a suspension device) and kept stationary.

  FIGS. 1A and 1B show a bearing sealing device 2 according to an embodiment of the present invention. The sealing device 2 includes a bearing unit A as shown in FIG. In other words, a bearing unit for wheel support (hub) provided with bearing rings 10 and 12, which are arranged so as to be relatively rotatable, and a plurality of rolling elements (balls) 18 incorporated so as to be able to roll between the bearing rings 10 and 12. The inside of the unit bearing is shielded from the outside, and the inside is kept sealed (airtight and liquid tight). Specifically, as the races 10 and 12, a stationary wheel 12 fixed to a vehicle body component (for example, a knuckle (not illustrated) of a suspension device) and a wheel component (for example, a disc wheel (not illustrated)) are provided. The rotating wheels 10 that are fixed and rotate together with the wheel constituent members are disposed to face each other so as to be relatively rotatable, and are formed on the stationary wheel 12 and the rotating wheel 10, respectively, and between the track surfaces 10 s and 12 s facing each other, and the track A plurality of rolling elements (balls) 18 are assembled so as to be capable of rolling between the surfaces 10t and 12t, thereby forming a bearing unit A.

  In this case, the stationary wheel 12 is integrally formed with a fixing flange 12f that protrudes outward (in the diameter expansion direction) from the outer peripheral surface 12a, and a fixing bolt is inserted into the fixing hole 12h that passes through the fixing flange 12f. By inserting (not shown) and fastening it to the vehicle body side, the stationary wheel 12 can be fixed to a knuckle of a suspension device (suspension) not shown.

  On the other hand, the rotating wheel 10 is provided with a hub 14 having a substantially cylindrical shape, and the hub 14 is fixed to a disk wheel (not shown) of a wheel via a brake rotor (not shown) of a brake. It is configured to rotate with the disc wheel. Note that a hub flange 14f for fixing (externally fitting) the brake rotor and the disc wheel on the outboard side of the hub 14 is continuously provided along the circumferential direction.

  The hub flange 14f extends outward (in the direction of diameter expansion of the hub 14) beyond the stationary ring 2, and a plurality of through holes (bolt holes) are provided in the vicinity of the extended edge along the circumferential direction. 14h is provided. A brake rotor and a disc wheel (not shown) are each provided with a plurality of through holes (as an example, the same number as the bolt holes 14h) that can communicate with the bolt holes 14h. Then, by inserting the hub bolt 14b from the bolt hole 14h into the through hole and fastening (tightening) with a hub nut (not shown), the brake rotor and the disc wheel can be positioned and fixed with respect to the hub flange 14f. it can.

The hub 14 is configured such that an annular inner ring structure 16 is fitted on the inboard side thereof. For example, a plurality of rolling elements (balls) 18 are provided between the stationary ring 12 and the hub 14. In the assembled state, the inner ring structure 16 is applied to the step 14s formed on the hub 14, and then the inboard side end of the hub 14 (the right end in FIG. 1 (a)) is crimped to thereby form the inner ring. The component 16 can be fixed to the inboard side of the hub 14, and a predetermined preload can be applied to the bearing unit A (more specifically, the rolling elements (balls) 18).
Instead of the above-described caulking and fixing, for example, after the inner ring component 16 is externally fitted to the stepped portion 14s formed on the hub 14, it is tightened by a fastening member such as a nut from the inboard side. The inner ring component 16 may be fixed to the inboard side of the hub 14 in some cases.

  In such a bearing unit A, the sealing device 2 includes a pack seal (hereinafter referred to as pack seal 2) having a structure (so-called package structure) in which the slinger 22, the core metal 24, and the seal 26 are combined so that the cross-sectional shape is substantially rectangular. ).

  The slinger 22 has a cylindrical shape extending in a predetermined direction. The slinger 22 is fixed to the rotating wheel 10 (specifically, the inner ring component 16) (hereinafter referred to as a slinger fixing portion) 22a, and the slinger is fixed. It is composed of a disc portion (hereinafter referred to as a slinger disc portion) 22b that is continuous with the extending end on one side of the portion 22a and extends at a predetermined angle with respect to the slinger fixing portion 22a.

  In FIG. 1 (b), a slinger fixing portion 22a is formed in a cylindrical shape extending in a predetermined direction (left and right direction in the figure) with a predetermined length (distance in the same direction in the figure), and a slinger disk portion 22b. Has a predetermined length (distance in the vertical direction in the figure) substantially perpendicular to the slinger fixing part 22a, and the diameter of the slinger fixing part 22a is continuously expanded from one extending end (right end in the figure). The configuration of the slinger 22 formed in an annular flat plate shape (ring plate shape) extending in the direction (upward direction in the figure) is shown. That is, in this case, the slinger 22 is configured so that the longitudinal cross-sectional shape is substantially L-shaped, and is press-fitted into the rotating wheel 10 (inner ring component 16) of the bearing unit A and fixed (specifically, And is configured to rotate together with the rotating wheel 10 (inner ring structure 16).

  Further, in this case, the slinger 22 is provided with a fitting allowance for fitting to the rotating wheel 10 (inner ring constituting body 16) with respect to the inner diameter dimension (specifically, the inner diameter dimension of the slinger fixing portion 22a). It is configured. That is, the slinger 22 has an inner diameter dimension of the slinger fixing portion 22a that is the outer diameter dimension of the rotating wheel 10 (inner ring constituent body 16) (specifically, the rotating wheel 10 (inner ring constituent body 16) is engaged with the slinger fixing section 22a. It is configured to have a size smaller than the surface to be abutted (diameter size of the upper surface in FIG. 1C (hereinafter referred to as the fitting surface 16b)) by the amount of the fitting allowance. . At this time, the fitting allowance to be set in the slinger fixing portion 22a of the slinger 22 may be arbitrarily set according to the size of the rotating wheel 10 (inner ring structure 16).

The size (extension length and thickness (the vertical distance in FIG. 1B)) of the slinger fixing portion 22a, and the size (extension length, length of the slinger disc portion 22b). The thickness (dimensions such as the distance in the left-right direction in the figure) and the diameter) is arbitrarily set according to the size and shape of the rotating wheel 10 (inner ring component 16) of the bearing unit A. Then there is no particular limitation.
Further, the inclination angle of the slinger disc portion 22b with respect to the slinger fixing portion 22a is not particularly limited, and may be arbitrarily set according to the use conditions of the pack seal 2 and the like.

  Further, the material and forming method of the slinger 22 are not particularly limited, and for example, the slinger 22 may be made of a predetermined metal plate (steel plate) and the metal plate (steel plate) may be formed by pressing. In this embodiment, the case where the slinger 22 is made of stainless steel is assumed as an example. By making the slinger 22 made of stainless steel in this way, rusting occurs on the outer peripheral surface (upper surface in FIG. 1B) 22u of the slinger fixing portion 22a, which is a sliding contact surface with a lip 261 of the seal 26 described later. It is possible to effectively prevent the lip 26l from being damaged when sliding against the outer peripheral surface 22u.

  The cored bar 24 has a cylindrical shape extending in a predetermined direction, a fixed part (hereinafter referred to as a cored bar fixing part) 24a fixed to the stationary ring 12, and one side of the cored bar fixing part 24a. It is composed of a disc part (hereinafter referred to as a cored bar part) 24b that is continuous with the extending end and extends at a predetermined angle with respect to the cored bar fixing part 24a.

  In FIG. 1 (b), the cored bar fixing portion 24a is formed in a cylindrical shape extending in a predetermined direction (left and right direction in the figure) with a predetermined length (distance in the same direction in the figure). The portion 24b has a predetermined length (distance in the vertical direction in the figure) at a substantially right angle to the metal core fixing part 24a, and extends to one extending end (left end in the figure) 24t of the metal core fixing part 24a. The structure of the cored bar 24 formed in an annular flat plate shape (ring plate shape) continuously extending in the diameter reducing direction (downward in the figure) is shown. That is, in this case, the core metal 24 is configured so that the longitudinal cross-sectional shape is substantially L-shaped, and is press-fitted and fixed (specifically, fitted) to the stationary ring 12 of the bearing unit A, It has a structure that is kept stationary at all times.

  Further, in this case, the cored bar 24 is configured by providing a fitting allowance for fitting to the stationary wheel 12 with respect to the outer diameter dimension (specifically, the outer diameter dimension of the cored bar fixing portion 24a). ing. That is, the outer diameter of the cored bar fixing portion 24a is equal to the inner diameter of the stationary ring 12 (specifically, the diameter of the surface on which the stationary ring 12 is fitted (contacted) with the cored bar fixing unit 24a). ) And a size larger than the fitting allowance. At this time, the fitting allowance to be set in the core metal fixing portion 24a of the core metal 24 may be arbitrarily set according to the size of the stationary ring 12 and the like.

  The size (extension length and thickness (distance in the vertical direction in FIG. 1B)) of the core metal fixing portion 24a and the size (extension length) of the core metal disc portion 24b. The thickness (the distance in the left-right direction in the figure) and the dimensions such as the diameter) are arbitrarily set according to the size and shape of the stationary ring 12 of the bearing unit A, and are not particularly limited here. . Further, the inclination angle of the cored bar part 24b with respect to the cored bar fixing part 24a is not particularly limited, and may be arbitrarily set according to the use conditions of the pack seal 2 and the like. Furthermore, the material and the forming method of the cored bar 24 are not particularly limited. For example, the cored bar 24 is made of a predetermined metal plate (made of a steel plate) and may be formed by pressing the metal plate (steel plate). .

  Further, the seal 26 is interposed between the slinger 22 and the cored bar 24 that are arranged to face each other with a predetermined interval, and is connected to one of the slinger 22 and the seal cored bar 24 and is in sliding contact with the other. Is made. In the configuration shown in FIG. 1 (b), as an example, the seal 26 includes a core metal fixing portion 24a and a core metal disc portion 24b of the core metal 24 (specifically, the inner surfaces thereof (the lower surface of FIG. Right side)), and a plurality of (for example, three) lips 261 are provided so as to extend toward the slinger 22 (specifically, the slinger fixing portion 22a and the slinger disc portion 22b). is doing.

  As the material of the seal 26, various elastic materials (for example, resin materials such as rubber and plastic) may be arbitrarily selected and applied according to the material of the slinger 22 and the cored bar 24. Further, the number and shape of the lips 261 provided on the seal 26 are not limited to the configuration shown in FIG. 1B. For example, two lips 261 may be provided on the seal 26, or four or more lips may be provided. The lip 261 may be provided. Further, the connection between the metal core 24 and the seal 26 (various elastic materials) may be performed by arbitrarily selecting various methods such as adhesion, caulking, coating, and injection molding. In the present embodiment, an example is given. Assuming that the core metal 24 and the seal 26 (various elastic materials) are connected by vulcanization molding.

  Then, the core 26 to which the seal 26 is connected so that the lip 26l of the seal 26 abuts (slidably contacts) the slinger 22 (specifically, the slinger fixing portion 22a and the slinger disc portion 22b). A sealing device (pack seal) 2 is configured by combining the slinger 22 so that the profile of the cross-section is substantially rectangular.

  The pack seal 2 is not particularly limited to the configuration shown in FIG. 1 (b). For example, the seal has two divided configurations, one is connected to a slinger, the other is connected to a core bar, and the slinger is connected to the slinger. It is good also as a structure which makes the seal | sticker connected in sliding contact with the metal core, and makes the seal | sticker connected with the metal core slidably contacted with the slinger.

  In the present embodiment, the slinger 22 is subjected to electrodeposition coating (so-called cation coating) at least on the slinger fixing portion 22a. In the configuration shown in FIG. 1B, as an example, electrodeposition coating (so-called cationic coating) is applied to the entire surface of the slinger 22, that is, the entire surface of the slinger fixing portion 22a and the slinger disc portion 22b. A cation coating (hereinafter referred to as a slinger coating) 22c is formed on the slinger fixing portion 22a and the slinger disc portion 22b.

  The electrodeposition coating (so-called cationic coating) on the slinger 22 is at least the slinger fixing portion 22a, more specifically, the slinger that is a contact surface (fitting surface) with the rotating wheel 10 (inner ring structure 16). If it is applied to the inner peripheral surface of the fixing portion 22a (the lower surface in the figure (hereinafter referred to as the fitting surface 22s)), the slinger 22 is not necessarily configured as shown in FIG. It does not have to be applied to the entire surface. For example, an electrodeposition coating (so-called cation coating) may be applied only to the fitting surface 22s of the slinger fixing portion 22a, and a cationic coating (slinger coating) may be formed only on the fitting surface 22s. .

Here, an example of a procedure for applying electrodeposition coating (so-called cationic coating) to the slinger 22 will be described below.
As described above, in the present embodiment, the slinger 22 is made of stainless steel as an example, but generally stainless steel is difficult to be subjected to electrodeposition coating (so-called cationic coating) (coating is poor and the coating film is poor. Therefore, a phosphoric acid film treatment is performed as a pretreatment. In addition, when the said phosphoric acid film process is inadequate, a nickel plating process etc. may be performed as a pre-processing as needed.

  After the pretreatment, the slinger 22 is submerged in a coating tank containing the paint, and the paint is electrically applied by passing a direct current through the slinger 22 and the paint while being immersed in the paint. . Then, the slinger coating film 22c can be formed by drying and curing the paint applied to the slinger 22.

  At that time, the thickness of the slinger coating film 22c is determined by the grinding roughness (surface roughness after grinding) with respect to the fitting surface 16b of the rotating wheel 10 (inner ring structure 16) with the slinger fixing portion 22a, and the slinger by press working. It is preferable to set it to be equal to or greater than the total dimension of the depths of the axial scratches (streaks) generated with respect to the fitting surface 22 s during molding. By setting the slinger coating film 22c to such a thickness, the grinding roughness (surface roughness after grinding) with respect to the fitting surface 16b of the rotating wheel 10 (inner ring structure 16) is adjusted by the slinger coating film 22c. In addition, scratches (streaks) on the fitting surface 22s are covered with the slinger coating film 22c, and the surface of the slinger 22 (specifically, the fitting surface 22s of the slinger fixing portion 22a) is slid by the slinger coating film 22c. The surface state can be obtained.

  Then, the pack seal 2 is assembled to the bearing unit A by press-fitting the slinger 22 formed with the slinger coating film 22c into the rotating wheel 10 (inner ring structure 16) from the inboard side.

  Thus, by applying electrodeposition coating (so-called cation coating) to the slinger 22 (slinger fixing portion 22a and slinger disc portion 22b) and forming a slinger coating film 22c, for example, the slinger 22 by press working is formed. Even when an axial flaw (streaks) is generated on the fitting surface 22s by a press during molding, the flaws (streaks) can be covered with the slinger coating 22c. Thereby, the fitting surface 22s of the slinger 22 is in a smooth surface state, and it is possible to completely avoid a situation in which water enters the portion of the flaw (streaks) from the outside of the bearing unit A.

  Further, by forming the slinger coating film 22c on the slinger 22 (specifically, the slinger fixing portion 22a), the slinger coating film 22c serves as a so-called packing. The rotating wheel 10 (specifically, the inner ring constituting body 10) can be brought into close contact with the fitting surface 16b, and foreign matter intrusion (such as muddy water immersion) from the fitting portion can be reliably prevented.

  In addition, when performing electrodeposition coating (so-called cation coating) on the slinger 22 (slinger fixing portion 22a and slinger disc portion 22b), electrodeposition coating (so-called so-called cation coating) is applied to the rotating wheel 10 (inner ring structure 16) described later. There is no need to perform baking (heating treatment) or post-treatment (polishing after electrodeposition coating, etc.) required for applying cationic coating. For this reason, it is possible to apply electrodeposition coating (so-called cationic coating) to the slinger 22 more easily than the rotating wheel 10 (inner ring structure 16).

  Here, in the configuration shown in FIG. 1B, since the electrodeposition coating (so-called cation coating) is applied to the entire surface of the slinger 22 as described above, the seal connected to the slinger disc portion 22b. 26 on the outer peripheral surface 22u of the slinger fixing portion 22a and the outboard side surface of the slinger disc portion 22b (the left side surface in the figure)) 22v, which are slidable contact surfaces with a plurality of (for example, three) lips 26l. A slinger coating film 22c is also formed. Thus, even when the slinger coating 22c is formed on the slidable contact surfaces 22u, 22v with the lip 261, the slidable contact state between the slidable contact surfaces 22u, 22v and the lip 261 does not change, and the seal The sealing performance of 26 (lip 26l) is not lowered.

  In the present embodiment, in addition to the slinger 22, electrodeposition coating (so-called cation coating) is applied to the rotating wheel 10, specifically, the inner ring structure 16. In the configuration shown in FIG. 1B, as an example, an electrodeposition coating (so-called cation coating) is applied to a surface (hereinafter referred to as an outer surface) other than the raceway surface 10t of the inner ring structure 16, and the outer surface A cationic coating film (hereinafter referred to as an outer surface coating film) 10c is formed.

  The electrodeposition coating (so-called cationic coating) on the inner ring structure 16 is at least a fixed portion with the slinger 22, more specifically, a fitting surface (contact surface) with the slinger fixing portion 22a (fitting surface 22s). ) As long as it is applied to 16b, it does not necessarily have to be applied to the entire outer surface of the inner ring component 16 as in the configuration shown in FIG. For example, an electrodeposition coating (so-called cation coating) may be applied only to the fitting surface 16b of the inner ring structure 16, and a cationic coating film (outer surface coating film) may be formed on the fitting surface 16b. .

Here, an example of a procedure for performing electrodeposition coating (so-called cation coating) on the inner ring structure 16 will be described below.
The inner ring structure 16 is formed by forging or casting and subjected to heat treatment, and then subjected to high temperature tempering under predetermined baking conditions (heating temperature and heating time), and the inner ring structure 16 after the tempering is performed. It is finished to a predetermined dimension by grinding.
Next, the inner ring structure 16 finished to a predetermined size is subjected to a phosphoric acid film treatment, and further sufficiently baked (heat treatment) under predetermined baking conditions (heating temperature and heating time) in order to avoid hydrogen embrittlement.
In addition, since each baking condition (heating temperature and heating time) mentioned above is arbitrarily set according to the shape of the inner ring | wheel structure 16 and the capability of a baking furnace, it does not specifically limit here.

Then, after performing these pretreatments, the inner ring component 16 is submerged in the coating tank containing the paint, and a direct current is passed through the inner ring component 16 and the paint while being immersed in the paint. Thus, the paint is electrically applied. Then, a cationic coating film can be formed by drying and hardening the coating material applied to the inner ring structure 16. At this time, a cationic coating film is formed on the entire surface of the inner ring structure 16. That is, the outer surface coating film 10c is formed, and the cationic coating film is also formed on the raceway surface 10t.
Therefore, in order to remove the cationic coating film formed on the raceway surface 10t, the following post-treatment is further performed.

  In this case, in the post-processing, high-precision polishing is performed on the raceway surface 10t on which the cationic coating film is formed, and first, the cationic coating film is removed from the raceway surface 10t. Subsequently, using a grindstone having a coarser grain than the grindstone used in the polishing process for removing the cationic coating film, a sparse structure, and a low degree of bonding, the raceway surface 10t from which the cationic coating film has been removed is applied. Polishing is performed to finish the raceway surface 10t so as to have good roughness and surface properties (so-called mirror surface state). As described above, the polishing process for the raceway surface 10t is performed in two steps. Specifically, the first polishing process is performed for the purpose of removing the cationic coating film, and the second polishing process is performed for the purpose of finishing the raceway surface 10t. It is preferable to perform the polishing process. Thereby, the removal of the cationic coating film and the smooth surface treatment on the raceway surface 10t can be performed efficiently and accurately.

  Note that the thickness of the outer surface coating film 10c is determined when the slinger 22 is formed by pressing (grinding roughness (surface roughness after grinding)) with respect to the fitting surface 16b of the inner ring component 16 with the slinger fixing portion 22a. It is preferable to set it to be equal to or greater than the total dimension of the depths of axial flaws (streaks) generated on the mating surface 22s. By setting the outer surface coating film 10c to such a thickness, the grinding roughness (surface roughness after grinding) with respect to the fitting surface 16b of the rotating wheel 10 (inner ring structure 16) is changed to the outer surface coating film 10c. The outer surface coating film 10c covers the scratches (streaks) on the fitting surface 22s, and the outer surface of the inner ring component 16 (specifically, the fitting surface 16b) is covered with the outer surface coating film. A smooth surface can be obtained by 10c.

  Then, the inner ring structure 16 on which the outer surface coating film 10 c is formed is assembled to the hub 14, and the hub 14 integrated with the stationary ring 12, the rolling elements (balls) 18 and the outboard side seal 30 is assembled. Assemble.

  Thus, by applying electrodeposition coating (so-called cationic coating) to the inner ring structure 16 and forming the outer surface coating film 10c, for example, when the inner ring structure 16 after tempering is ground, the fitting surface Even if an axial flaw (streaks) occurs in 16b, the flaws (streaks) can be covered with the outer surface coating film 10c. Thereby, the fitting surface 16b of the inner ring structural body 16 becomes a smooth surface state, and it is possible to completely avoid a situation in which water enters the portion of the flaw (streaks) from the outside of the bearing unit A.

  In addition, since the outer surface coating film 10c serves as a so-called packing by forming the outer surface coating film 10c on the outer surface (specifically, the fitting surface 16b) of the inner ring structure 16, the inner ring The fitting surface 16b of the structure 10 can be brought into intimate contact with the fitting surface 22s of the slinger 22, and entry of foreign matters (such as muddy water immersion) from the fitting portion can be reliably prevented.

  Furthermore, by forming the outer surface coating film 10c on the outer surface (specifically, the fitting surface 16b) of the inner ring component 16, the outer surface (particularly, the fitting surface 16b) of the inner ring component 16 is formed. Rusting can be prevented, and even if rusting occurs, the progress can be greatly delayed. Thereby, the fitting state of the fitting surface 16b of the inner ring structure 10 and the fitting surface 22s of the slinger 22 can be kept constant over a long period of time, and the contact state (that is, the sealed state of the bearing unit A). Can continue to maintain.

  As shown in FIG. 1A, the effect of preventing rusting on the inner ring structure 16 is a bearing in which the inner ring structure 16 and the hub 14 form an integral structure by caulking to constitute the rotating wheel 10. In the case of unit A, it becomes very large. That is, in this case, after the inner ring component 16 is inserted from the inboard side of the hub 14 and applied to the stepped portion 14 s, a crimping region provided in advance on the inboard side of the hub 14 is used as the inner ring component 16. 14d is formed by caulking along the end face 16a on the inboard side. Thereby, the inner ring structure 16 is brought into close contact with the hub 14 while being sandwiched between the caulking portion 14d and the stepped portion 14s, and the inner ring structure 16 and the hub 14 are integrated. For this reason, the rusting of the inner ring structural body 16 after caulking increases the internal stress with respect to the caulking force of the inner ring structural body 16 and causes so-called delayed fracture (crack). By preventing this, such delayed fracture (crack) can be effectively prevented.

  As described above, the electrodeposition coating (so-called cationic coating) is applied to the slinger 22 of the pack seal 2 and the electrodeposition coating (so-called cationic coating) is applied to the rotating wheel 10 (inner ring component 16). The formed slinger coating film 22c and the outer surface coating film 10c can be easily thickened, and the slinger coating film 22c and the outer surface coating film 10c can be made very strong. Further, it is easy to control the thickness (coating thickness) when forming the slinger coating 22c and the outer surface coating 10c.

As a result, according to the present embodiment, a uniform slinger coating film 22c can be formed on the slinger 22 of the pack seal 2, and a uniform outer surface coating can be applied to the rotating wheel 10 (inner ring structure 16). The film 10c can be formed. Thereby, the slinger 22 of the pack seal 2 and the rotating wheel 10 (inner ring component 16) are fitted via the slinger coating film 22c and the outer surface coating film 10c, so that a constant sealing performance ( For example, a sealing structure of a bearing device (wheel support bearing unit) that can maintain a muddy water intrusion prevention effect and has excellent durability can be easily realized.
Therefore, by applying such a sealing structure, the bearing unit A can be stably rotated with a certain accuracy over a long period of time.

  In the present embodiment described above, electrodeposition coating (so-called cationic coating) is applied to both the slinger 22 of the pack seal 2 and the rotating wheel 10 (inner ring component 16), and the slinger coating 22c and the outer surface are applied. The coating film 10c is formed, but either one, that is, only the slinger 22 of the pack seal 2 or only the rotating wheel 10 (inner ring component 16) is subjected to electrodeposition coating (so-called cationic coating), Only one of the slinger coating film 22c and the outer surface coating film 10c may be formed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the structural example of the sealing structure of the bearing apparatus which concerns on this invention, Comprising: (a) is principal part sectional drawing which shows the structure of a bearing unit (hub unit bearing), (b) is electrodeposition coating (cation). Sectional drawing which shows the structure of the sealing device (pack seal) to which coating was given, (c) is sectional drawing which shows the structure of the rotary wheel (inner ring structure) to which electrodeposition coating (cationic coating) was given. Sectional drawing which shows the structural example of the conventional sealing device (pack seal).

Explanation of symbols

2 Sealing device (pack seal)
DESCRIPTION OF SYMBOLS 10 Rotating wheel 10c Outer surface coating film 12 Stationary wheel 14 Hub 16 Inner ring structure 16b Fitting surface 22 Slinger 22a Slinger fixing part 22b Slinger disk part 22c Slinger coating 22s Fitting surface 24 Core metal 24a Core metal fixing part 24b Core Gold disc part 26 Seal 26l Lip A Bearing unit (hub unit bearing)

Claims (4)

In order to keep the inside of the bearing device provided with at least a pair of raceways opposed to each other so as to be relatively rotatable and a plurality of rolling elements incorporated so as to be able to roll between the raceways, a slinger, A bearing sealing device having a structure in which a core metal and a seal are combined so that a contour shape of a cross section is substantially rectangular,
The slinger has a cylindrical shape extending in a predetermined direction, is continuous with the slinger fixing portion fixed to the one raceway ring, and the extension end on one side of the slinger fixing portion, and is connected to the slinger fixing portion. And is composed of a slinger disc extending at a predetermined angle,
The cored bar has a cylindrical shape extending in a predetermined direction, and is continuous with the cored bar fixing part fixed to the other raceway ring and the extending end on one side of the cored bar fixing part. Consists of a cored bar disk portion extending at a predetermined angle with respect to the fixed part
The seal is interposed between the slinger and the cored bar which are arranged to face each other at a predetermined interval, is connected to one of the slinger and the cored bar, and is in sliding contact with the other,
A bearing sealing device, wherein at least a slinger fixing portion is electrodeposited on the slinger.   The bearing sealing device according to claim 1, wherein the slinger and the metal core are made of metal, and the seal is connected to the slinger and the metal core by vulcanization molding.   A stationary wheel fixed to the vehicle body component member, a track ring formed by rotating and rotating the wheel component member fixed and rotating together with the wheel component member so as to be relatively rotatable, and a stationary wheel and a rotating wheel, respectively. A wheel support bearing unit comprising a plurality of rolling elements incorporated so as to be able to roll between raceways facing each other, in order to keep the inside airtight and liquid-tight. A bearing unit for supporting a wheel, wherein the bearing sealing device according to 2 is provided. A stationary wheel fixed to the vehicle body component member, a track ring formed by rotating and rotating the wheel component member fixed and rotating together with the wheel component member so as to be relatively rotatable, and a stationary wheel and a rotating wheel, respectively. A wheel support bearing unit comprising a plurality of rolling elements incorporated so as to be able to roll between raceways facing each other, and a sealing device for keeping the inside airtight and liquid tight,
The sealing device is interposed between the slinger fixed to the rotating wheel, the cored bar fixed to the stationary wheel, and the slinger and the cored bar arranged to face each other at a predetermined interval. And a seal that is slidably in contact with the other, and has a structure in which the slinger, the cored bar, and the seal are combined so that the profile of the cross section is substantially rectangular,
The wheel support bearing unit is characterized in that an electrodeposition coating is applied to at least a fixed portion of the surface of the rotating wheel with the slinger.

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