JPH1048233A - Rotation detection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure a rotor to the outer ring of a bearing while reducing the radial space by molding the molding part of a metal fixing member into a resin cover and then fitting the non-molding part to a press fitting part provided at the forward end of a bearing. SOLUTION: A metal fixing member 100 abutting against the inner face of the outer ring 5 at a bearing part is molded into a cover 7 and the molding part 1002 of the fixing member 100 is provided with an S-shaped bend in the resin in order to prevent removal. The non-molding part 1001 of the fixing member 100 is press fitted while abutting against the press fitting part 51 formed on the inner circumferential surface of the outer ring 5 at the bearing part when a cover 7 integrated with a sensor body is secured to the body side. Consequently, the outer ring 5 at the bearing part can be secured to the cover 7 simply through the non-molding part 1001 having thickness of a metal plate and it is applicable even when only a small gap can be ensured between the inner circumferential surface of the outer ring 5 at the bearing part and the outer circumferential surface of a rotor 3. Consequently, the radial thickness at the non-molding part 1001 to be secured to the outer ring 5 at the bearing part of the cover 7 can be made thin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotation detecting device for detecting a rotation state of a subject.

[0002]

2. Description of the Related Art As an apparatus of this kind, the present applicant has proposed a rotation detecting apparatus shown in FIG. As described in Japanese Patent Application No. 8-7360, the rotation detecting device shown in FIG. 6 is, for example, a rotating shaft 1 of a subject (not shown).
The rotor 3 is fixed to the tip of the rotor via the bearing inner ring 2,
The rotating shaft 1 and the bearing inner ring 2 are rotatably fixed to the bearing outer ring 5 via bearing balls 4. Inside the rotor 3, a sensor body 6 as a detection unit for detecting the rotation speed of the rotating shaft 1 is provided.

[0003] The sensor body 6 is composed of an electromagnetic coil 61, a permanent magnet 62, magnetic switch parts 63 and 64, etc., and these are molded in a resin body. The resin forms the cover 7 that covers the inside of the bearing outer ring 5 while molding the above components. This reduces the number of parts when assembling the rotation detecting device. Further, the cover 7 includes a fitting portion 71 that is fitted to the bearing portion outer ring 5 to fix the cover 7 to the bearing portion outer ring 5. A cylindrical metal ring 8 is fitted in the groove in the fitting portion 71, and the cover 7 is firmly fixed by the metal ring 8 in a simple manufacturing process. .
Further, a seal O is provided at a position on the distal end side of the bearing outer ring 5.
A ring 9 is provided, and the outside of the cover 7 and the outer ring 5 of the bearing portion are provided.
The inside of the bearing is shut off to prevent intrusion of dust and the like and leakage of lubricating oil and the like on the bearing side.

[0004]

According to recent technical trends,
There is a demand to reduce the diameter of the bearing outer ring 5, and also to increase the diameters of the rotor and the sensor body 6 as much as possible in order to maintain the detection accuracy of the rotation detecting device. Therefore, there is a tendency that only a small space is taken between the rotor 3 and the bearing outer ring 5.

However, in the above configuration, the cover 7 is fixed by the metal ring 8 made of metal, and when the thickness of the fitting portion 71 in which the metal ring 8 is fitted is reduced in the radial direction. In addition, the fitting portion 71 of the resinous cover 7 is easily deformed due to vibration or stress at the time of press-fitting and fixing the cover 7 to the bearing outer ring 5, so that the metal ring 8 and the cover 7 are separated and the cover 7 is hardly fixed. A problem is expected.

Accordingly, the present invention provides a rotor 3 and a bearing outer ring 5.
It is an object of the present invention to provide a rotation detecting device that can reduce the radial space between the cover 7 and the cover 7 and can securely fix the cover 7 to a fixed body.

[0007]

In order to solve the above-mentioned problems, a rotation detecting device according to the present invention is fixed to a bearing portion, and includes a detecting portion formed by at least a magnet and an electromagnetic coil; A rotor having a cylindrical rotor switch portion between the bearing portion and the detection portion, which is fixed to the tip of the shaft and has different magnetic resistances alternately provided in the rotation direction of the rotating body, and at least a magnet and A resin cover for molding the electromagnetic coil, covering each end of the bearing portion and the rotating shaft, a mold portion formed of metal and molded into the resin of the resin cover, and a non-molded portion; And a metal fixing member for realizing the fixing of the resin cover to the bearing portion. The fixing of the resin cover to the bearing portion is performed by a press-fitting portion provided at the tip of the bearing portion. This is realized by fitting and fixing the non-molded portion.

As described above, the metal fixing member is integrated with the resin cover in the molded portion, and the resin cover is fixed to the bearing portion in the non-molded portion. Therefore, when detecting the rotation state of the rotating shaft in a configuration in which the rotor is sandwiched between the detection unit and the bearing unit at the end of the bearing unit, the resin cover at the end of the bearing unit is fixed by the non-molded portion of the metal fixing member. It can be carried out. That is, since the press-fitting is realized at the non-molded portion of only the metal portion, not the portion where the thickness is increased by resin molding, the radial thickness of the rotating shaft can be suppressed. When the press-fitting portion is provided on the inner circumferential surface of the bearing portion as described in claim 4, after the resin cover is fixed, a non-molded portion exists between the rotor and the inner circumferential surface of the bearing portion. However, since the non-molded portion is made of only metal and is thin, even if the space between the rotor and the inner circumferential surface of the bearing portion is narrowed, press-fitting can be reliably realized, which is advantageous in design.

Further, as described in claim 3, the molded portion of the metal fixing member may be bent in a resin cross section into a substantially S-shaped cross section and molded.
At this time, detachment of the metal fixing member from the resin cover in the axial direction of the rotating shaft is prevented. Further, the rotation detecting device according to claim 5 may be employed. That is, while being fixed to the bearing portion, the detecting portion formed by at least the magnet and the electromagnetic coil, and fixed to the tip of the rotating shaft, and portions having different magnetic resistances are alternately provided in the rotating direction of the rotating shaft. A rotor having a cylindrical rotor switch portion between the detection portion and the bearing portion, and a resin cover for molding at least a magnet and an electromagnetic coil, and the resin cover is provided at the tip of the rotating shaft and the bearing portion. To shield to cover the tip,
A bearing portion has a resin cover side facing surface facing the bearing portion side leading end surface, and a seal member is provided between the bearing portion side leading surface and the resin cover side facing surface in the axial direction of the rotating shaft. I do.

[0010] In such a configuration, a seal member exhibiting a sealing property between the resin cover and the bearing portion is disposed not on the inner circumferential surface of the bearing portion but on the distal end surface of the bearing portion. That is, the seal member is arranged on a plane substantially perpendicular to the axial direction of the rotating shaft. As described above, by fixing the surface of the rotating shaft and the bearing portion, that is, a surface different from the inner circumferential surface where the press-fitting portion exists, as the sealing surface,
It is not necessary to provide the thickness of the seal member in the radial direction of the rotation shaft, and the entire thickness in the radial direction can be suppressed.

Further, if the groove for fitting the seal member is formed on the tip end surface of the resin cover, the resin cover is easier to process than the bearing portion. .

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a rotation detecting device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of the rotation detecting device according to the first embodiment. In this rotation detecting device 1, a rotor 3 is fixed to a base end of a rotating shaft 1 of a wheel (not shown) as a subject via a bearing inner ring 2, and the rotating shaft 1 and the bearing inner ring 2 It is rotatably fixed to a bearing outer ring 5 as a fixed body via a bearing ball 4. Inside the rotor 3, a sensor main body 6 as a detection unit is disposed. A cover 7 is formed on the base end side (right side in the figure) of the bearing outer ring 5, outside the rotor 3 and the sensor body 6. The cover 7 is formed of a synthetic resin, and the sensor body 6 is molded at the time of molding to be integrally formed with the cover 7. Further, the cover 7 also integrally molds the terminal 10 electrically connected to the electromagnetic coil 61, and forms the terminal 10 on the vehicle body side.
An electric signal can be transmitted to a CU or the like. By forming the sensor body 6 and the like as a cover in this way, the number of components can be reduced when the rotation detecting device is assembled, which is advantageous in the manufacturing process.

The rotor 3 is formed in a cylindrical shape concentric with the rotating shaft 1 and is disposed so as to protrude in the bearing nut direction. A portion of the rotor 3 facing the sensor body 6 has windows formed at predetermined intervals along the rotation direction of the rotor 3, and the other portion has a rotor switch portion 3 formed of a magnetic column.
1 is provided. The sensor main body 6 is branched at substantially the same width as the window at the position facing the rotor switch 31,
A pair of cores 60 provided with claw-shaped magnetic switches 63 and 64, respectively, and an electromagnetic coil 61 wound on a spool
And a permanent magnet 62. S of permanent magnet 62
The pole is in contact with one core 60, and the N pole is in contact with the other core 60. At this time, a magnetic flux path may be formed between the permanent magnet and the core 60 via a magnetic material. The magnetic switches 63 and 64 are composed of a permanent magnet 62, one core 60, a magnetic switch 63, a portion of a magnetic material of the rotor switch unit 31, a magnetic switch 64 and the other core 60.
The closed magnetic circuit passing through the two magnetic switches 63, 64
Are formed and cut off simultaneously by both. Thus, the rotor switch unit 31 and each of the magnetic switches 63 and 64 are
A closed magnetic circuit is formed when the columnar magnetic body portion having low magnetic resistance of the rotor switch portion 31 and the claw-shaped protrusion portions of the magnetic switch portions 63 and 64 face each other.
When the window portion having a high magnetic resistance and the concave portion between the claws of the magnetic switch portions 63 and 64 face each other, the magnetic path is shut off. As described above, the two magnetic switch units 63 and 64 are configured so that the formation of the closed magnetic circuit is interrupted at two locations.
Therefore, the change in magnetic flux can be increased and the rotation detection accuracy can be improved as compared with the case where the closed magnetic circuit is shut off at one place in the closed magnetic circuit.

Next, the features of the present invention in the cover 7 will be described. The cover 7 has a cover-side end surface 72 that contacts the bearing-unit outer-ring-side end surface 52 located on the base end side of the bearing-unit outer ring 5 from outside the rotor 3 and the sensor body 6. An annular groove 73 surrounded by the protruding portions 721 and 722 is formed on the cover-side end surface as shown in FIG. An O-ring as a sealing member for sealing the inside and the outside of the sensor body 6 is disposed in the groove 73, and exhibits sealing properties between the bearing outer ring side end surface 52 and the cover side end surface 72. ing.

The cover 7 is molded with a metal fixing member 100 which is in contact with the inner surface 51 of the bearing outer ring 5. Mold part 100 of this fixing member 100
Reference numeral 2 has a bent portion which is bent into a substantially S-shaped cross section in the resin, thereby preventing the fixing member 100 from coming off in the rotation axis direction (the left-right direction in the figure). The non-resin molded portion 1001 of the fixing member 100 that is not resin-molded is used to fix the cover 7 in which the sensor body 6 is integrated to the vehicle body side, that is, to fix the cover 7 to the outer ring of the bearing portion. It is press-fitted so as to come into contact with a press-fit portion 51 formed on the inner circumferential surface of the outer ring 5. As shown in FIG. 2, the non-resin molded portion 1001 is also formed in an annular cylindrical shape.

The operation and effect when the rotation detecting device is configured as described above will be described below. First, the fixing member 100
However, the effect of fixing the cover 7 with the non-resin molded portion 1001 and the molded portion 1002 and fixing the cover 7 with the non-resin molded portion 1001 and the press-fit portion 51 of the bearing outer ring will be described. As can be seen from the figure, the fixing member 100
This fixing member 10 is viewed from the non-resin mold portion 1001 which comes into contact with the press-fitting portion 51 for realizing the fixing of the cover 7.
0 and the cover 7, ie, the part that forms the body, ie, the mold part 1
002 is disposed outside the bearing outer ring 5 in the rotation axis direction. Therefore, the fixing between the bearing outer ring 5 and the cover 7 is performed by the non-resin molded portion 10 having only the metal plate thickness.
01, the applicability is improved even when only a small gap can be secured between the inner peripheral surface of the bearing outer ring 5 (the press-fit fixing portion 51) and the outer peripheral surface of the rotor 3. That is, as compared with the device shown in FIG. 6 having a radially double structure including the resin fitting portion 71 and the metal ring 8, the bearing portion outer ring of the cover 7 is secured while securing the same strength and fixing ability. 5 (the non-resin molded portion 1001) can be reduced in radial thickness.

Next, the seal member is connected to the outer ring side end face 5 of the bearing portion.
The function and effect when the cover 2 is disposed between the cover 2 and the cover-side end surface 72 will be described. As can be seen from the figure, the O-ring 109 realizes a seal in the radial direction of the rotating shaft 1. That is, when the arrangement position of the O-ring 109 is viewed with reference to the bearing outer ring 5, the O-ring 109 is not disposed at the press-fit portion 51 which is the inner peripheral surface of the bearing outer ring 5, Bearing ring outer ring side end face 5 substantially at right angles to
2. Therefore, even if an inexpensive O-ring or the like is used as the seal member, a gap between the outer peripheral surface of the rotor 3 and the inner peripheral surface of the bearing outer ring 5 is not required by the thickness of the O-ring.

Further, since the O-ring 109 is disposed on a surface different from the non-resin molded portion 1001 which is a press-fit surface of the fixing member 100, the O-ring 109 is moved to the bearing portion outer ring 51 of the non-resin molded portion 1001 when the cover 7 is fixed. When the O-ring 109 is subjected to the stress at the time of press-fitting and is rubbed against the surface of the press-fitting portion 51 at the time of press-fitting, maintenance of the sensor body 6, or the like, the O-ring is damaged or deformed. This can be minimized.

Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a partial cross-sectional view of the rotation detecting device, showing a shape portion of the fixing member 100 that realizes fixing of the cover 7 to the bearing outer ring 5, which is a characteristic portion of the present invention. Also, components having the same functions and effects as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. Book second
Also in the embodiment, the metal fixing member 100 has a non-resin molded portion 1001 and a molded portion 1002. The non-resin mold portion 1001 has a double structure with a cross-sectional bent shape. A metal cylindrical outer end of the double structure is in contact with a protrusion 74 formed on the cover 7. The molded portion 1002 is bent into an L-shaped cross section, and has a portion in which both inner and outer surfaces are molded with resin and a portion in which resin is present only on the outer side. The fixing member 100 is bent by the L-shaped portion.
Is prevented.

Even if the above-described shape is adopted, the first
The same operation and effect as the embodiment can be obtained. further,
In the second embodiment, since the mold portion 1002 of the fixing member 100 is simply bent in an L shape, the processing is simple. Next, a third embodiment of the present invention will be described with reference to FIG. 4 which is a partial sectional view showing a characteristic portion of the present invention. In the third embodiment as well, components having the same functions and effects as those of the above-described embodiments will be denoted by the same reference numerals and will not be described in detail.

The feature of the third embodiment is that the molded portion 1002 of the metal fixing member 100 is bent in an L-shaped cross section toward the inside of the protrusion 74. By doing so, the outside (right side in the figure) of the cover 7 can be formed thinner than the protruding portion 74, and the diameter of the cover 7 can be reduced. Next, a fourth embodiment of the present invention will be described with reference to FIG. 5, which is a partial sectional view showing a characteristic portion of the present invention. In the fourth embodiment as well, components having the same functions and effects as those of the above-described embodiments are denoted by the same reference numerals and will not be described in detail.

The feature of this embodiment is that O
Instead of the ring, a substantially rectangular ring having an L-shaped cross section is arranged in a stepped groove 731 provided on the inner diameter side of the cover-side end face 72. The stepped groove 731 has an advantage that processing is easy. With this configuration, the same operation and effect as those of the above-described embodiments can be obtained. The present invention can be variously modified without being limited to the embodiments described above.

For example, in the above-described embodiments, the non-resin molded portion 1001 of the fixed member 100 is
To abut against the inner circumferential surface. This allows the surface processing of the press-fitting portion 51 of the inner circumferential surface of the bearing outer ring 5 to be performed simultaneously with the portion where the bearing ball 4 comes into contact,
This is because the number of processing steps is advantageous. However, regardless of this, the press-fit portion 1001 may be arranged on the outer peripheral surface of the bearing outer ring 5. In this case, the surface processing of the press-fit portion formed on the outer circumferential surface of the bearing outer ring 5 is performed separately from the inner circumferential surface of the bearing outer ring 5, and the non-resin molded portion 1001 of the fixing member 100 is It is formed corresponding to the outer diameter of the bearing outer ring 5 corresponding to the press-fit portion provided on the circumferential surface. In this case, the same effect as in the above-described embodiment can be obtained. In this case, the fixing member 1
It is not always necessary to provide a non-resin molded part and a molded part in 00, and a gap between the outer peripheral surface of the rotor 3 and the inner peripheral surface of the bearing outer ring 5 is ensured even if the press-fitted part is also molded. can do.

In the above-described embodiments, the configuration of the fixing member 100 having the non-resin mold portion 1001 and the mold portion 1002 is combined with the arrangement configuration of the seal member for realizing sealing on a surface different from the press-fitting surface. However, if at least one configuration is provided, it is possible to obtain an operational effect that a gap between the outer peripheral surface of the rotor 3 and the inner peripheral surface of the bearing outer ring 5 can be secured.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a configuration of a rotation detection device according to a first embodiment.

FIG. 2 is a front view of a cover in which the sensor body is formed as viewed from the inside.

FIG. 3 is a partial sectional view of a second embodiment.

FIG. 4 is a partial sectional view of a third embodiment.

FIG. 5 is a partial sectional view of a fourth embodiment.

FIG. 6 is a cross-sectional view illustrating a configuration of a rotation detection device described in the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotation shaft 2 Bearing inner ring 3 Rotor 31 Rotor switch part 4 Bearing ball 5 Bearing outer ring 51 Press-fit part 52 Bearing outer ring end face 6 Sensor main body 60 Core 61 Electromagnetic coil 62 Permanent magnet 63, 64 Magnetic switch part 7 Cover 72 Cover Side end face 73 Groove section 100 Fixing member 1001 Non-resin mold section 1002 Mold section 109 O-ring

Claims (6)

[Claims] 1. A rotation detecting device for detecting a relative rotation state of a rotating shaft supported by a bearing portion, wherein the detecting portion is fixed to the bearing portion and formed at least by a magnet and an electromagnetic coil; A rotor that is fixed to the tip of the rotating shaft and that has a cylindrical rotor switch portion in which portions having different magnetic resistances are alternately provided in the rotating direction of the rotating body between the bearing portion and the detecting portion; A resin cover for molding at least the magnet and the electromagnetic coil, and covering each end of the bearing portion and the rotating shaft; and a mold portion molded on the resin of the resin cover.
A metal fixing member comprising a non-mold portion and a metal fixing member for fixing the resin cover to the bearing portion by fitting and fixing the non-mold portion to a press-fit portion provided at the tip of the bearing portion. A rotation detecting device, comprising: 2. The rotation detecting device according to claim 1, wherein the non-molded portion of the metal fixing member is formed in a cylindrical shape according to a shape of a press-fit portion of the bearing portion. 3. The rotation according to claim 1, wherein the mold portion of the metal fixing member is bent and molded into a substantially S-shaped cross section in the resin cover. Detection device. 4. The non-molded part of the metal fixing part,
4. The press-fit portion of the bearing portion, which is located between the rotor and the bearing portion, is formed on the inner circumferential surface of the bearing portion facing the rotation shaft. 5. The rotation detecting device according to any one of the above. 5. A rotation detecting device for detecting a rotation state of a rotating shaft supported by a bearing portion, wherein the detecting portion is fixed to the bearing portion and formed at least by a magnet and an electromagnetic coil. A rotor fixed to the tip of the rotating shaft and having a cylindrical rotor switch portion between the detecting portion and the bearing portion, the portion having different magnetic resistance being alternately provided in the rotating direction of the rotating shaft; A resin cover that molds the magnet and the electromagnetic coil; and the resin cover covers the tip of the rotating shaft and the tip of the bearing to shield the tip of the bearing. A resin cover-side facing surface facing the leading end surface; and an axis of the rotating shaft between the bearing portion-side leading surface and the resin cover-side facing surface. Rotation detecting device characterized by comprising a sealing member in direction. 6. A groove in which the seal member can be embedded is formed in an annular shape on the resin cover side facing surface, and the seal member is disposed in the groove. The rotation detecting device according to claim 4 or claim 5.