JPH11174068A - Rolling bearing unit with encoder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize a structure for sealing between a hub 3 and a core bar forming a seal ring at a low cost. SOLUTION: An encoder 21 made of a rubber magnet is supported and fixed to the side surface of a support plate part 19 for forming a core bar 8a of a seal ring 7a. A bent part 22 bent to the support plate part 19 side at right angles is provided on the outer peripheral edge of the encoder 21. With the seal ring 7a installed on the end part of a hub 3, the leading edge of the bent part 22 is elastically abutted against a first chamfer 23 formed on the outer peripheral edge of the opening of the hub 3 extending over the whole periphery.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention A rolling bearing unit with an encoder according to the present invention constitutes a rotation speed detecting device for rotatably supporting a wheel of an automobile with respect to a suspension device and detecting a rotation speed of the wheel. Use to do.

[0002]

2. Description of the Related Art Rolling bearing units are used to rotatably support the wheels of an automobile with respect to a suspension system.
Further, in order to control an antilock brake system (ABS) or a traction control system (TCS), it is necessary to detect the rotation speed of the wheel. For this reason, a rolling bearing unit with an encoder for rotatably supporting the wheel with respect to a suspension device and detecting the rotational speed of the wheel has been widely used.

FIG. 4 shows an example of a conventional structure of a rolling bearing unit with an encoder used for such a purpose, which is described in JP-A-9-21821. A pair of inner rings 1, 1 each being an inner ring equivalent member
Is fitted and fixed to an axle that does not rotate (see FIG. 1; omitted in FIG. 4) in a state of being assembled into the suspension device. Inner ring raceways 2, 2 are formed on the outer peripheral surface of each of the inner rings 1, 1, respectively. In addition, double rows of outer raceways 4 are formed on the inner peripheral surface of the hub 3 which is a member equivalent to the outer race which rotates during use. A plurality of balls 5, 5, each of which is a rolling element, are provided between each of the outer raceways 4, 4 and each of the inner raceways 2, 2, and a hub 3 is provided around each of the inner races 1, 1.
Is rotatably supported. In the case of a heavy-weight rolling bearing unit for an automobile, a tapered roller may be used instead of the balls 5 and 5 as the rolling element.
A wheel (not shown) is fixed to a flange 6 provided on the outer peripheral surface of the hub 3.

Also, the inner end of the hub 3 (inside means a side which is closer to the center in the width direction of the vehicle when assembled to the vehicle, and is a right side in each drawing. Is referred to as “outside” and left in each figure.), A metal core 8 constituting the seal ring 7 is fitted and fixed, and between the inner peripheral surface of the hub 3 and the outer peripheral surfaces of the inner rings 1, 1. Is closed at the inner end opening of the space 9 existing in the space. The core metal 8 has a substantially J-shaped cross section and is formed in an annular shape as a whole. By bending the outer peripheral edge of the annular main portion 10 outward (to the left in FIG. 4) at right angles, the hub 8 is provided. A cylindrical portion 11 for external fitting and fixing is formed at the inner end of the cylindrical member 3.

The inner peripheral edge of the main portion 10 is bent slightly outward to form a bent edge 12, and a sealing material 13 made of an elastic material is fixed to the inner peripheral edge of the bent edge 12 by baking or the like. doing. And this sealing material 13
The inner peripheral edge of the pair of seal lips 14, 14 formed on the inner peripheral edge of the inner ring 1 is slidably contacted with the outer peripheral surface of the inner end of the inner ring 1, thereby sealing the opening at the inner end side of the space 9. Further, an annular encoder 15 is provided on the inner surface of the main portion 10.
Are supported and fixed by bonding or the like. This encoder 1
Numeral 5 is formed in a ring shape by a permanent magnet, and has an S pole and an N
The poles are arranged alternately and at equal intervals in the circumferential direction. Further, another seal ring 16 is fitted and fixed to the outer end of the hub 3 to seal the outer end opening of the space 9.

In the case of the above-described rolling bearing unit with a rotation speed detecting device, the wheel fixed to the hub 3 can be rotatably supported on an axle on which the inner rings 1 and 1 are externally fitted. When the hub 3 rotates together with the wheels, the output of a sensor (not shown) facing the side surface of the encoder 15 fixed to the hub 3 changes. The frequency at which the output of this sensor changes is proportional to the rotational speed of the wheel. Therefore, if the output signal of this sensor is input to a controller (not shown), the rotational speed of the wheel can be obtained and the ABS and TCS can be appropriately controlled.

[0007]

However, the conventional structure as described above has the following disadvantages. That is,
In the case of the above-described conventional structure, the core 8 constituting the seal ring 7 has the cylindrical portion 11 constituting the core 8 externally fixed to the outside of the space 9 at the inner end of the hub 3. . For this reason, through the minute gap between the inner peripheral surface of the cylindrical portion 11 and the outer peripheral surface of the inner end of the hub 3, which is a fitting portion between the cored bar 8 and the hub 3, Foreign matter such as rainwater may enter. In order to prevent such inconvenience, a sealing material is attached to a part of the cored bar 8 which comes into contact with the inner end of the hub 3 over the entire circumference, and the sealing material is attached to the cored bar 8. By clamping between the inner end of the hub 3
Sealing between the cored bar 8 and the inner end of the hub 3 may be considered. However, providing a seal member separate from the seal ring 7 at the contact portion between the core bar 8 and the hub 3 in this manner is not preferable because it increases the manufacturing cost. It is conceivable to apply an adhesive to a contact portion between the cored bar 8 and the hub 3 to seal between the cored bar 8 and the hub 3, but this also increases the cost. A rolling bearing unit with an encoder according to the present invention has been invented in view of the above situation.

[0008]

A rolling bearing unit with an encoder according to the present invention has an inner ring raceway on the outer peripheral surface, similar to the above-mentioned conventional rolling bearing unit with an encoder, and has a member corresponding to an inner ring which does not rotate during use. An outer ring-equivalent member having an outer raceway on its inner peripheral surface and rotating at the time of use; a plurality of rolling elements rotatably provided between the inner raceway and the outer raceway; and an elastic seal. The entire body is formed in an annular shape by a material and a metal core supporting the sealing material, and this metal core is fitted and fixed to an end of the outer ring-equivalent member, and the leading edge of the sealing material is the inner ring-equivalent member or A seal ring that closes an end opening of a space between an outer peripheral surface of the inner ring equivalent member and an inner peripheral surface of the outer ring equivalent member by slidingly contacting a surface of the member fixed to the inner ring equivalent member; Supported and fixed on the side of gold And a annular encoder arranged alternately and S poles and N poles in the circumferential direction. In particular, in the rolling bearing unit with the encoder according to the present invention, the encoder is constituted by an elastic magnet such as a rubber magnet or a plastic magnet, and the core is fitted to an end of the outer ring equivalent member. In a fixed state, a part of the encoder is elastically brought into contact with the end of the outer ring-equivalent member over the entire circumference.

[0009]

The wheel is rotatably supported by the rolling bearing unit with encoder according to the present invention constructed as described above, and the operation of detecting the rotational speed of the wheel is performed by the above-described conventional rolling bearing unit with encoder. Is the same as In particular, in the case of the rolling bearing unit with the encoder of the present invention, a part of the encoder abutting on the entire periphery of the end of the outer ring-equivalent member is formed by the end of the outer ring-equivalent member and the end of the outer ring-equivalent member. Seal the space between the seal ring and the core of the seal ring fitted and fixed to the portion. For this reason, between the end portions of the outer ring-equivalent member and the core metal, the rainwater enters a space between the outer peripheral surface of the inner ring-equivalent member and the inner peripheral surface of the outer ring-equivalent member, which is a portion where the rolling elements are installed. It is possible to prevent foreign matter such as the like from entering.
Moreover, in the case of the present invention, since the sealing action as described above is obtained by contacting a part of the encoder, which is a rubber magnet, with the end of the outer ring-equivalent member, the manufacturing cost is not increased. Absent.

[0010]

1 and 2 show a first embodiment of the present invention. The feature of the present embodiment lies in the structure of a portion for sealing between the inner end of the hub 3 which is an outer ring equivalent member and the core metal 8a of the seal ring 7a attached to the inner end of the hub 3. Since the structure and operation of the other parts are the same as those of the conventional structure shown in FIG. 4 described above, the same parts are denoted by the same reference numerals, and duplicated description is omitted or simplified. The following description focuses on the characteristic portions and the portions different from the above-described conventional structure.

The seal ring 7a attached to the inner end of the hub 3 comprises a cored bar 8a and a sealing material 13a. The metal core 8a is formed into a generally annular shape with a substantially T-shaped cross section by bending a metal plate such as a steel plate or a stainless steel plate. That is, at the middle portion in the diameter direction of the cored bar 8a,
A part of the metal plate constituting the metal core 8a is protruded outward, and the metal plate is further folded back 180 degrees so as to be overlapped with each other so that the cylinder protrudes outside the metal core 8a (left side in FIGS. 1 and 2). The part 17 is formed. Also, of the core metal 8a,
A radially inner portion of the cylindrical portion 17 is a ring-shaped closing plate portion 18, and a radially outer portion of the cylindrical portion 17 is a ring-shaped support plate portion 19.

Further, the entire sealing material 13a is formed in an annular shape by an elastic material such as rubber, elastomer or the like.
It is fixed to the inner peripheral edge of the closing plate portion 18 over the entire periphery by baking or the like. When such a seal ring 7a is attached to the inner end of the hub 3, the cylindrical portion 17 of the cored bar 8a is pressed into the inner peripheral surface of the inner end of the hub 3 and the support plate 19 is attached to the hub 3. The inner end surface of the hub 3 is brought into contact with the entire circumference. In this state, the sealing material 1
Each of the leading edges of the plurality (three in the illustrated example) of the seal lips 14a formed on the inner ring 3a is attached to the inner inner ring 1 respectively.
Outer peripheral surface of (inner ring equivalent member) and sensor holder 2 described later
The outer end of the space 9 in which the balls 5, 5 are installed is sealed by sliding the outer surface of the ball 0 over the entire circumference.

An encoder 21 is supported and fixed on the inner surface of the support plate 19. This encoder 21
Is formed by mixing powder of a magnetic material such as ferrite into an elastic material such as rubber or plastic to form an entire ring shape. The encoder 21 is magnetized in the axial direction (the left-right direction in FIGS. 1 and 2), and changes the magnetization direction alternately and at equal intervals in the circumferential direction. Therefore, on the inner surface of the encoder 21, S poles and N poles are arranged alternately and at equal intervals in the circumferential direction. Then, the encoder 21 is connected to the support plate 1 that constitutes the cored bar 8a.
9 is supported and fixed to the inner surface by baking, bonding, own magnetic attraction force, or the like.

The portion of the outer peripheral edge of the encoder 21 which is located diametrically outward from the outer peripheral edge of the support plate portion 19 is bent at a right angle toward the outside in the axial direction (the left side in FIGS. 1 and 2). A bent portion 22 is provided. Then, the leading edge (the left edge in FIGS. 1 and 2) of the bent portion 22 is
The first chamfered portion 23 formed on the outer peripheral edge of the opening of the hub 3 is elastically brought into contact with the entire periphery. That is, in the free state, the distal end edge of the bent portion 22 slightly projects outward in the axial direction from the outer surface of the support plate portion 19. In this manner, the tip edge of the bent portion 22 is elastically brought into contact with the first chamfered portion 23 in a state where a magnetic attraction force is also applied, so that the bent portion 22 is in contact with the inner end of the hub 3. Seal between the core 8a.

A sensor (not shown) embedded and supported in a sensor case 24 made of synthetic resin is opposed to the inner surface of the encoder 21 via a minute gap. In the case of the present example, the sensor case 24 is supported and fixed by the sensor holder 20 which is externally fitted and fixed to the step portion 33 of the axle 25 inserted through the inner diameter sides of the inner rings 1 and 1. This sensor holder 20
Is formed by bending a metal plate such as a steel plate or a stainless steel plate into a substantially L-shaped cross section, and forming the whole in an annular shape. A fixed cylindrical portion 26 for externally fitting and fixing to the step portion 33 is provided on an inner peripheral edge portion.
The outer peripheral edge has a bent inclined portion 27 which is bent in a direction opposite to the fixed cylindrical portion 26.

A cutout 28 is formed in a part of such a sensor holder 20 so as to open to the outer peripheral side of the sensor holder 20. In order to form such a notch 28, a part of the sensor holder 20 parallel to each other is formed.
A pair of cuts is formed so as to reach the outer peripheral edge side of the sensor holder 20, and a portion between the pair of cuts is bent and raised in a substantially L-shape in a direction opposite to the bent inclined portion 27, thereby forming a spring piece 29. And Also, this spring piece 29
An engagement projection 30 is formed at the tip of the sensor holder 20 so as to project toward the main body of the sensor holder 20.

The sensor case 24 has first engagement grooves 31 formed on both sides in the circumferential direction (front and rear surfaces in FIG. 1) so as to be engageable with both end edges of the notch 28. Note that, in a state where both end edges of the notch 28 are engaged with the first engagement grooves 31, the sensor case 24 does not come off in the axial direction of the sensor holder 20 (the left-right direction in FIG. 1). In this way, the dimensions of each part are regulated. In the middle part of the sensor case 24, on the side opposite to the encoder 21,
The second engagement groove 32 is formed linearly in the circumferential direction of the sensor holder 20 (the front and back direction in FIG. 1).

The second engagement groove 32 inserts the sensor case 24 into the notch 28 while engaging each of the first engagement grooves 31 with both end edges of the notch 28. In the cut state, it engages with the engagement projection 30 formed at the tip of the spring piece 29 to prevent the sensor case 24 from falling out of the notch 28. In this state, the sensor case 24 engages the first engagement grooves 31 with both end edges of the notch 28 and the second engagement grooves 32 and the engagement protrusions 30. Based on the engagement, it is supported and fixed to the sensor holder 20. The bent inclined portion 27 formed on the outer peripheral edge of the sensor holder 20 is
In a state where the sensor holder 20 is externally fitted and fixed to the step portion 33 of the axle 25, the sensor holder 20 covers the outer side in the diameter direction of the encoder 21, and a large foreign matter such as a stone is formed between the encoder 21 and the sensor holder 20. To prevent ingress.
Since the above-described sensor holder 20 can be easily manufactured by press working or the like, it can be manufactured relatively inexpensively.

The rolling bearing unit with the encoder of the present embodiment configured as described above rotatably supports the wheel, and detects the rotation speed of the wheel by the above-described conventional rolling bearing unit with the encoder. Is the same as In particular, in the case of the rolling bearing unit with the encoder of the present embodiment, the leading edge of the bent portion 22 formed on the encoder 21 is formed over the entire periphery of the first chamfered portion 23 formed on the outer peripheral edge of the opening of the hub 3. It is elastically contacted. Therefore, a sufficient seal is provided between the inner end of the hub 3 and the metal core 8a constituting the seal ring 7a, and the balls 5, 5 are inserted from between the inner end face of the hub 3 and the metal core 8a. Foreign matter such as rainwater can be prevented from entering the installed space 9. In this case, in the case of this example, the above-described sealing action is achieved without providing an independent sealing material or applying an adhesive to a part of the cored bar 8a or a part of the hub 3. Of the bent portion 22 which is a part of the first chamfered portion 23. For this reason, the production cost does not increase to ensure the sealing property.

Next, FIG. 3 shows a second embodiment of the present invention.
An example is shown. In the case of this example, an annular seal portion formed by a part of the encoder 21a is formed on a continuous portion between the outer surface of the support plate portion 19 constituting the metal core 8b of the seal ring 7b and the outer peripheral surface of the cylindrical portion 17 as well. 34 is attached along the entire circumference. That is, such a seal portion 34 is formed integrally with the main body of the encoder 21a when the encoder 21a, which is a rubber magnet or a plastic magnet, is molded with the cored bar 8b. The support 21 is connected to the main body 21a through a plurality of small holes 35 formed in the inner peripheral edge of the support plate portion 19.

In such a seal portion 34, the cylindrical portion 17 is pressed into the inner peripheral surface of the inner end of the hub 3, and the outer surface of the support plate portion 19 is brought into contact with the inner end surface of the hub 3. In this state, the hub 3 is held between the second chamfered portion 36 formed on the inner peripheral edge of the opening and the continuous portion in an elastically compressed state. Then, the sealing portion 34 seals between the cored bar 8 b and the inner end of the hub 3. In the case of the present example, the sealing portion 34 is provided with the second chamfered portion 36.
And the continuous portion, the cross section is sandwiched by an annular space portion having a substantially triangular cross section. The volume of this space is larger than the volume of the seal portion 34. Therefore, the outer side surface of the support plate portion 19 and the inner end surface of the hub 3 that constitute the cored bar 8b are not welded by sandwiching the seal portion 34. Therefore, the positioning of the encoder 21a supported on the inner side surface of the support plate portion 19 is not impaired, and the support of the encoder 21a does not become unstable. Other configurations and operations are the same as those of the above-described first example.

As described above, the feature of the present invention is that the hub 3
And a structure for sealing between the cores 8a and 8b of the seal rings 7a and 7b attached to the inner end of the hub 3 and the inner end of the hub 3. Therefore, as the structure of the rolling bearing unit itself, various types of conventionally known structures, including the structure shown in FIGS.

[0023]

The rolling bearing unit with encoder according to the present invention is constructed and operates as described above, so that the sealing performance of the mounting portion of the core metal constituting the seal ring can be ensured without increasing the manufacturing cost. .

[Brief description of the drawings]

FIG. 1 is a half sectional view showing a first example of an embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG. 1 showing only a main portion.

FIG. 3 is a view similar to FIG. 2, showing a second example of the embodiment of the present invention;

FIG. 4 is a half sectional view showing one example of a conventional structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Inner ring 2 Inner ring raceway 3 Hub 4 Outer ring raceway 5 Ball 6 Flange 7, 7a, 7b Seal ring 8, 8a, 8b Core metal 9 Space 10 Main part 11 Cylindrical part 12 Bending edge part 13, 13a Seal material 14, 14a Seal lip DESCRIPTION OF SYMBOLS 15 Encoder 16 Another seal ring 17 Cylindrical part 18 Blocking plate part 19 Support plate part 20 Sensor holder 21, 21a Encoder 22 Bent part 23 First chamfer part 24 Sensor case 25 Axle 26 Fixed cylindrical part 27 Bent inclination part 28 Notch 29 Spring piece 30 Locking projection 31 First engagement groove 32 Second engagement groove 33 Step 34 Seal part 35 Small hole 36 Second chamfered part

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G01D 5/245 G01D 5/245 X

Claims (1)

[Claims] 1. An inner ring-equivalent member having an inner raceway on an outer peripheral surface and not rotating during use, an outer race-equivalent member having an outer raceway on an inner peripheral surface and rotating during use, the inner raceway and the outer raceway And a plurality of rolling elements provided so as to be able to roll freely, a sealing material made of an elastic material, and a metal core supporting the sealing material, the entirety of which is formed in an annular shape. The outer peripheral surface of the inner ring-equivalent member and the outer ring are fitted and fixed to the end of the member, and the leading edge of the sealing material is brought into sliding contact with the surface of the inner ring-equivalent member or a member fixed to the inner ring-equivalent member. A seal ring for closing an end opening of a space between the inner peripheral surface of the corresponding member and a circle having S poles and N poles alternately arranged in the circumferential direction, supported and fixed on the side surface of the cored bar. Rolling bearing unit with encoder with annular encoder The encoder is configured by an elastic magnet, and a part of the encoder in a state where the core metal is fitted and fixed to an end of the outer ring equivalent member,
A rolling bearing unit with an encoder, wherein the rolling bearing unit with an encoder is elastically in contact with an end portion of the outer ring-equivalent member over the entire circumference.