JP2001056236A - Mounting structure of multipolar magnet encoder and seal member - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotation number detection device capable of protecting a rotation number detection part detecting the number of rotation of a bearing part and improving sensing performance and durability by far. SOLUTION: This mounting structure mounts a multipolar magnet encoder 2 detecting the number of revolutions and a seal member 3 for sealing. In this case, the seal member 3 has a reinforcing ring part 3b and a seal lip 3a, and the multipolar magnet encoder 2 is constituted in such a way that a magnetic ring 2a is arranged on an inner peripheral side of the seal member 3 by forming a circular shape. Consequently, it is possible to ensure a wide area for generating rotation pulse and obtain powerful pulse generation performance and high sensing performance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a seal structure for a bearing part which rotates relatively, and more specifically, to a method for detecting the rotational speed of front and rear or left and right wheels in an anti-lock brake system or a traction control system of an automobile. The present invention relates to a mounting structure of a seal member having a rotation detecting device.

[0002]

2. Description of the Related Art Hitherto, the following structure has been widely used as a wheel rotational speed detecting device for anti-skid for preventing skid of an automobile or for traction control for effectively transmitting a driving force to a road surface. . That is, the rotation number detecting device used in the above-mentioned portion includes an encoder that generates pulses by magnetism and a sensing sensor that senses magnetic pulses of the encoder. As a general structure, the bearing is sealed. Encoders are provided side by side with the seal device, and a seal with a rotation speed detecting device in which the sealing means and the rotation speed detecting means are integrated has been developed and put into practical use. Hereinafter, this will be described in detail with reference to the drawings.

[0003] An example of such a conventional example will be described with reference to the drawings. A sealing device as shown in FIG. 2 can be shown. In this seal device, a pulse generating ring 5 made of a magnetic material is directly attached to the outer surface of an oil seal 4 fitted to the outer ring 1a, and a magnetic pulse from the pulse generating ring 5 is disposed in close proximity to the rotation detecting sensor. 6 is characterized by a rotation number detecting structure for sensing and detecting. Here, the bearings 1a and 1b are prevented from leaking grease inside and from intrusion of moisture or foreign matter from the outside by the lip 4a slidingly contacting the inner ring 1b.

[0004]

However, such an oil seal 4 with the pulse generating ring 5 has the pulse generating ring 5 and the rotation speed detecting sensor 6 arranged so as to be exposed to the outside atmosphere, so that the oil seal 4 is scattered. If the foreign matter adheres and penetrates between the pulse generating ring 5 and the rotation speed detecting sensor 6 in a severe situation where the pulse generating ring 5 and the rotation speed detecting sensor 6 are directly exposed to This is a serious drawback as a rotational speed detecting device that causes damage and erroneously detects the rotational speed. To avoid such disadvantages, a bearing sealing device has been proposed as disclosed in Japanese Patent Application Laid-Open No. H10-160744 in which a pulse generating ring 5 as shown in FIG. However, this type of bearing sealing device with a pulse generating ring 5 normally arranges the pulse generating ring 5 in a radial direction to detect the rotational speed from outside the sealing element 7 via a rotational speed detecting sensor 6, Due to the narrow mounting space in the radial direction of the bearing, it is difficult to secure a large area of the pulse generating ring 5 and there is a disadvantage that the rotation speed sensing is weakened. The present invention has been made in view of the above-described drawbacks, and has as its object to provide a seal device having a wheel rotation number detecting device that completely protects a rotation number detecting unit and greatly improves sensing performance and durability.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings. As shown in FIG. 1, it is mounted on bearings 1a and 1b of a vehicle wheel or the like to detect the number of rotations and seal the bearing. A mounting structure of a multi-pole magnet encoder 2 and a seal member 3, wherein the seal member 3 includes a seal lip 3a made of an elastic material such as synthetic rubber and a reinforcing ring portion 3b made of a non-magnetic rigid material. 31b and flange 32b
A sealing lip 3a is formed on an inner peripheral portion of a flange portion 32b of the reinforcing ring portion 3b so as to surround the multipolar magnet encoder 2 from outside. The magnetic ring 2a of the other pole magnet encoder 2 has a cylindrical shape. The sealing member 3
Is disposed close to the inner peripheral surface of the cylindrical portion 31b, and the reinforcing ring portion 3
The rotation number detection sensor 6 is provided on the outer peripheral side of the cylindrical portion 31b of FIG.

As shown in FIG. 1, a multi-pole magnet encoder mounted in combination with a seal member 3 is a magnetic ring 2a formed by mixing a ferromagnetic material in an elastic material such as synthetic rubber, and a rigid support ring 2b. The magnetic ring 2a is formed in a rising shape close to the inner peripheral surface of the cylindrical portion 31b of the seal member 3.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention has the following excellent functions with the above structure. That is, the seal member 3 mounted and fixed to the bearing (the outer ring 1a in FIG. 1) has a multi-pole magnet encoder 2 that generates a pulse disposed inside the seal member 3, and the multi-pole magnet encoder 2 is located outside the seal member. Tube part 31b, flange part 32b, and seal lip 3a
And is completely shielded from the outside, so that it is completely protected from intrusion of water or foreign matter from the outside, and accurate rotation speed detection without malfunction can be guaranteed for a long period of time. .

In the generation of a pulse, the magnetic ring 2a of the multi-pole magnet encoder 2 is formed in a cylindrical shape as shown in FIG. Can secure a large area in
Further, the magnetic ring 2a is connected to the cylindrical portion 31b of the seal member 3.
Since it is arranged in a large-diameter dimension close to the inner peripheral surface, the area can be further enlarged.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The magnetic ring 2a made of an elastic material mixed with a ferromagnetic material according to the present invention is made of a powder or a granular material such as a quenching hardening material, a precipitation hardening material or a sintered material. It is mixed with an elastic material such as a resin, and if necessary, is press-molded into a support ring 2b to which a base treatment and an adhesive have been applied in advance, if necessary. In the shape of the magnetic ring 2a, the magnetic ring 2a is maintained in a cylindrical shape, and the cylindrical portion 3
It is desirable to form the support ring 2b in a rising shape close to 1b. With this structure, a magnetic pole portion having a large area can be obtained and the pulse generation performance can be maximized.

On the other hand, in the seal member 3, an axially wide pocket formed of a cylindrical portion 31b and a flange portion 32b is formed on the reinforcing ring portion 3b in order to maximize the magnetic ring 2a of the multipolar magnet encoder 2 contained therein. This pocket is sealed off by a seal lip 3a made of an elastic material.

In the mounting of the seal member 3 and the rotation speed detecting sensor 6, the magnetic ring 2a of the multi-pole magnet encoder 2 is disposed close to the cylindrical portion 31b of the seal member 3 as shown in FIG. It is preferable to mount the rotation speed detecting sensor 6 directly or close to the cylindrical portion 31b, since the highest sensing performance can be obtained, which is a preferable arrangement. What is important here is that the reinforcing ring 3b wrapping the magnetic ring 2a from outside is reinforced in order to allow the magnetic field generated by the magnetic ring 2a to penetrate and reach the rotation speed detecting sensor 6 with almost no resistance. The ring portion 3b is formed of a non-magnetic material, which has a strong protection structure and has very little influence on other portions.

Next, in the formation of the seal lip 3a, since the magnetic ring 2a of the multipolar magnet encoder 2 has a rising shape as described above, an extra space is created in the contact portion for attachment to the inner ring 1b. Thus, the seal lip 3a having no shape restriction can be arranged in the space, and a strong sealing structure can be obtained.

[0013]

According to the present invention, the magnetic ring 2a for generating a rotation pulse is formed in a cylindrical shape capable of securing a wide area, and is disposed on the maximum outer peripheral side. Pulse generation performance and high sensing performance can be obtained. Further, the magnetic pole portion is completely isolated from the outside air by the seal member 3 located on the outer side, and is protected from adhesion of foreign matter or lubricating oil to form an accurate and stable magnetic field. Only when this stable magnetic field is present, the sensing performance of the rotation speed detection sensor 6 is exhibited, and high-precision rotation detection is realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an embodiment showing a mounted state of the present invention.

FIG. 2 is a sectional view showing a conventional example not using the present invention.

FIG. 3 is a cross-sectional view showing another conventional example not using the present invention.

[Explanation of symbols]

 1a Outer ring 1b Inner ring 2 Other pole magnet encoder 2a Magnetic ring 2b Support ring 3 Seal member 3a Seal lip 3b Reinforcement ring 31b Cylindrical part 32b Flange part 4 Oil seal 5 Pulse generating ring 6 Rotational speed detection sensor 7 Seal element

Claims (2)

[Claims] In a mounting structure of a multi-pole magnet encoder and a seal member mounted on a bearing portion for detecting a rotation speed and performing sealing, the seal member is a seal lip made of an elastic material and a reinforcing ring made of a non-magnetic material. The reinforcing ring portion comprising a cylindrical portion and a flange portion has a seal lip formed on the inner peripheral portion of the flange portion and is arranged so as to wrap the multipolar magnet encoder from the outside, and the magnetic ring of the multipolar magnet encoder is A mounting structure for a multi-pole magnet encoder and a seal member, wherein a cylindrical shape is disposed close to the inner peripheral side of the cylindrical portion of the seal member, and a rotation speed detection sensor is provided in the cylindrical portion of the reinforcing ring portion. 2. A multi-pole magnet encoder comprising a magnetic ring formed by mixing a ferromagnetic material with an elastic body and a rigid support ring, wherein the magnetic ring has a rising shape close to a cylindrical portion of the seal member. 2. A molded article.
The mounting structure of the multi-pole magnet encoder and the seal member according to the above.