JP2006250607A - Rotational speed detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotational speed detector that ensures waterproofness, and can be assembled easily. <P>SOLUTION: The rotational speed detector 32 comprises a rotational speed detection element 41 for detecting the rotational speed of a rotating member 28; a casing 36 that accommodates the rotational speed detection element 41 and has an opening; and a lid 37 for blocking the opening in the casing 36. At a side section 46 of the casing 36 positioned between the rotating member 28 and the rotational speed detection element 41, the thickness of a portion that the rotational speed detection element 41 opposes is smaller than that of a portion to which the lid 37 is mounted for formation. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rotational speed detection device, and more particularly to a rotational speed detection device that detects the rotational speed of a bearing device or a mechanical device such as a railway vehicle or automobile that requires reliability.

  2. Description of the Related Art Conventionally, in a bearing device, a mechanical facility, or the like that supports an axle of a railway vehicle or an automobile, a rotational speed detector is used to detect the rotational speed of the axle. (For example, refer to Patent Document 1).

FIG. 4 shows a conventional structure described in Patent Document 1 in which the operation state of the bearing is detected by a sensor installed in the vicinity of the vehicle bearing. The axle 100 is rotatably supported by an axle box 102 of a bearing device via a rolling bearing 101. A cylindrical sensor unit 104 is attached to the lid 103 attached to the axle box 102 so as to face the encoder 106 fitted to the end cap 105 of the axle 100. The sensor unit 104 includes a rotation speed detection element that detects the rotation speed of the axle 100 via the encoder 106.
Special table 2001-500707 gazette

  By the way, it is desired that the sensor for detecting the rotational speed should make the distance between the rotational speed detecting element in the sensor and the steel gear to be detected as small as possible. In addition, waterproofness is required depending on the usage environment of the sensor. For this reason, in the conventional structure of FIG. 4, the rotational speed detection element is arranged at the distal end of the cylindrical case, and the distance between the rotational speed detection element and the gear to be detected is made as small as possible. The wall thickness is reduced.

  However, the sensor unit 104 shown in FIG. 4 has a problem that it is difficult to assemble because the rotational speed detection element is arranged at the tip of the cylindrical casing away from the opening.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to provide a rotation speed detection device that can be easily assembled while ensuring waterproofness.

The above object of the present invention is achieved by the following configurations.
(1) A rotational speed detection device comprising: a rotational speed detection element that detects the rotational speed of a rotational member; a housing that houses the rotational speed detection element and has an opening; and a lid that closes the opening of the housing. There,
In the side part of the housing located between the rotating member and the rotational speed detecting element, the thickness of the part facing the rotational speed detecting element is formed to be thinner than the thickness of the part to which the lid is attached. A rotational speed detection device characterized by that.
(2) The rotational speed detection device according to (1), further including at least one of a temperature detection element and a vibration detection element.
(3) The rotational speed detection device according to (2), wherein the rotational speed detection element is arranged on a side surface side of the casing from the at least one of the temperature detection element and the vibration detection element.

  According to the rotational speed detection device of the present invention, the rotational speed detection element is housed and provided with a housing having an opening and a lid that closes the opening of the housing, so that the detection device can be easily assembled and rotated. In the side part of the housing located between the member and the rotational speed detection element, the thickness of the part facing the rotational speed detection element is formed thinner than the thickness of the part to which the lid is attached. Reduce the thickness of the part facing the detection element to ensure the rotational speed detection performance, and increase the thickness of the part to which the lid is attached to ensure the seal area between the lid and the housing, Waterproofness can be maintained.

  Hereinafter, a rotational speed detection device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a railway vehicle bearing device in which the rotational speed detection device of the present invention is incorporated. In the railway vehicle bearing device 10, a hollow cylindrical axle 11 that supports and fixes a wheel (not shown) is rotatably supported by a double-row tapered roller bearing 13 that is a rolling bearing inside the axle box 12.

  The double row tapered roller bearing 13 is fitted into the axle box 12 and has a single outer ring 15 having a pair of outer ring raceway surfaces 14 (one outer ring raceway surface is not shown) inclined in a conical shape on the inner circumferential surface. And a pair of inner rings 17 (one inner ring is not shown) which is a rotating member that is fitted on the axle 11 and has an inner ring raceway surface 16 (one inner ring raceway face not shown) inclined in a conical shape on the outer peripheral surface. .) The double-row tapered roller bearing 13 includes a double-row tapered roller 18 and a double-row tapered roller 18 arranged in a circumferential direction between the outer ring raceway surface 14 of the outer ring 15 and the inner ring raceway surface 16 of the inner ring 17. Has an annular retainer 19 (one retainer is not shown). The double row tapered roller bearing 13 is loaded with a radial load due to the weight of various members and an arbitrary axial load, and a lubricant such as grease or lubricating oil is sealed in the bearing space.

  An inner ring spacer 20 is interposed between the pair of inner rings 17, and a pressing spacer 21 that presses the inner ring 17 in the axial direction is disposed on the axle 11 at an axial end portion of the inner ring 17. Has been. Further, a shaft end nut 22 that applies a pressing force toward the inner ring 17 to the pressing spacer 21 is disposed on the side away from the inner ring 17 of the pressing spacer 21 in a state of being screwed to the axle 11. Yes. That is, the shaft end nut 22 fixes the inner ring 17 in a state where the preload necessary for the double row tapered roller bearing 13 is applied by applying a pressing force to the pressing spacer 21 toward the inner ring 17 side. Depending on the use conditions, the preload may not be applied. Further, the shaft end nut 22 is prevented from loosening by engaging a rotation prevention ring 24 fixed to the outer end surface of the shaft end nut 22 by a bolt 23 with the outer peripheral surface of the end portion of the axle 11. The outer ring 15 is fitted and fixed to the axle box 12 at a step portion 25 formed near one end (left end in the figure) of the inner peripheral surface of the axle box 12 and a side portion near the other end (not shown). It is sandwiched between holding rings (not shown).

  Further, an iron seal case 26 for sealing the axial end of the tapered roller bearing 13 is fitted into the inner diameter surface of the outer end 15 in the axial direction. A seal ring 27 is disposed between the inner peripheral surface of the seal case 26 and the outer peripheral surface of the pressing spacer 21 and closes both end openings of the bearing space of the double row tapered roller bearing 13. With this configuration, the tapered roller bearing 13 prevents the grease enclosed in the bearing space from leaking to the outside and prevents foreign matter such as rainwater and dust from entering the bearing space from the outside.

  In addition, an encoder 28 that is a rotation member as a detection target that rotates in conjunction with the rotation of the axle 11 and the tapered roller bearing 13 is formed on the outer peripheral surface of the pressing spacer 21. The encoder 28 is formed in an external gear shape in which concave portions and convex portions are alternately provided at equal intervals in the circumferential direction, and changes the magnetic characteristics of the outer peripheral edge portion alternately and at equal intervals in the circumferential direction. .

  Also, a cover 29 is fixed to one end of the axle box 12 so as to close the opening of the one end, and the cylindrical portion 30 of the cover 29 penetrates in a radial direction at a position overlapping the encoder 28 in the axial direction. A sensor mounting hole 31 is formed. A rotation speed detection device 32 is fixed to the axle box 12 and the cover 29 by bolts 33 and 34 in the sensor mounting hole 31.

  As shown in FIGS. 2 and 3, the rotational speed detection device 32 closes the opening of the housing space 35 formed in the housing 36 and the substantially rectangular parallelepiped housing 36 that forms the housing space 35 having the opening. A flat lid 37. The housing 36 has a base 38 in which a bolt mounting hole 38 a is formed, extends toward the sensor mounting hole 31 of the cover 29, and is disposed so as to overlap the encoder 28 in the axial direction of the axle 11. . The housing 36 is made of a nonmagnetic material such as an aluminum alloy.

  The casing 36 has a rectangular shape that is substantially the same as the flat lid 37 at the peripheral edge 36a that surrounds the opening, and bolts 39a, 39b, 39c, and 39d disposed at the respective corners of the peripheral edge. The lid 37 is fixed by fastening. Therefore, the lid 37 that closes the opening of the accommodation space 35 is disposed in the axle box 12.

  A printed circuit board 40 is attached to the bottom side of the housing 36 in the accommodating space 35. The printed circuit board 40 has a rotational speed detecting element 41 for detecting the rotational speed of the encoder 28 and a magnet 42 for generating magnetic flux. A temperature detecting element 43 for detecting the temperature of the double row tapered roller bearing 13 and a vibration detecting element 44 for detecting the vibration of the double row tapered roller bearing 13 are mounted. Signals from these rotational speed detection element 41, temperature detection element 43, and vibration detection element 44 are transmitted to the outside via a signal cable 45.

  The rotational speed detection element 41 is disposed on the printed circuit board 40 in the vicinity of the side portion 46 of the housing 36 facing the encoder 28, and the magnet 42 is radially outward of the axle 11 with respect to the rotational speed detection element 41. Adjacent to each other. Further, the temperature detection element 43 and the vibration detection element 44 are attached to the printed circuit board 40 at a position away from the rotation speed detection element 41 with respect to the encoder 28.

  The side portion 46 of the housing 36 located between the encoder 28 and the rotation speed detecting element 41 is a portion 46a to which the lid 37 is attached in the height direction of the housing 36, that is, the bolts 39a and 39c are twisted. Except for the part to be inserted, it is formed by cutting out into an arc shape. For this reason, the thickness of the portion 46b facing the rotational speed detection element 41 in the side portion 46 is formed to be at least partially thinner than the thickness b2 of the portion 46a to which the lid is attached. The thickness b1 at the intermediate portion in the width direction of the casing 46 of the portion 46b facing each other is formed thinner than the thickness b2 of the portion 46a to which the lid is attached. A partial cylindrical surface 47 is formed in the portion 46 b facing the rotational speed detection element 41, and the partial cylindrical surface 47 is disposed so that a part of the encoder 28 is accommodated therein.

  The radius of curvature of the partial cylindrical surface 47 has a radius of curvature slightly larger than that of the encoder 28. Further, the portion 46b facing the rotational speed detection element 41 has a thickness b1 of 0.1 to 0.5 mm, preferably 0.2 to 0.3 mm, in the intermediate portion in the width direction (center portion when viewed from above). It is processed as follows.

  The rotational speed detection device 32 configured in this way detects the rotation of the shaft end nut 22 fixed to the axle 11 by the rotational speed detection element 41 as a change in magnetic flux due to the concave and convex portions of the encoder 28, and the rotational speed The rotation speed of the axle 11 is detected by outputting, for example, a pulsed electric signal from the detection element 41 to the control circuit and performing a predetermined process.

  At this time, the portion 46b facing the rotational speed detecting element 41 on the side portion 46 of the housing 36 is formed with a small thickness, and one of the encoders 28 is placed in the partial cylindrical surface 47 formed in this portion 46b. Therefore, the distance between the encoder 28 and the rotation speed detection element 41 can be reduced, and the rotation speed detection performance can be ensured.

  Further, since the portion 46a to which the lid is attached is formed thick, the area of the seal portion between the lid 37 and the housing 36 is ensured to be waterproof. .

  Therefore, according to the rotation speed detection device 32 of the present embodiment, the rotation speed detection element 41 is accommodated, and the housing 36 having an opening and the lid 37 that closes the opening of the housing 36 are provided. In the side portion 46 of the housing 36 positioned between the encoder 28 and the rotation speed detection element 41, the thickness of the portion 46b facing the rotation speed detection element 41 is attached to the lid 37. Since the thickness of the portion 46b opposed to the rotational speed detection element 41 is reduced, the rotational speed detection performance is ensured and the thickness of the portion 46a to which the lid 37 is attached is formed. By increasing the thickness, a sealing area between the lid 37 and the housing 36 can be secured, and waterproofness can be maintained.

  In addition, since the rotational speed detection device 32 includes the temperature detection element 43 and the vibration detection element 44, the temperature detection element 43 and the vibration detection element 44 are accommodated in a single housing 36, and a compact configuration is achieved. Along with the rotational speed of the row tapered roller bearing 13, temperature and vibration can be detected.

  Furthermore, since the rotational speed detection element 41 is arranged on the side face 46 side of the housing 36 with respect to the temperature detection element 43 and the vibration detection element 44, it can be arranged near the side portion 46 in the accommodation space 35 of the housing 36. And the rotational speed detection performance can be improved.

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
The present invention is not limited as long as the thickness of the portion facing the rotational speed detection element on the side of the housing is thinner than the thickness of the portion to which the lid is attached. The shape is arbitrary and is not limited to the arc shape of the present embodiment.

  The bearing device in which the rotational speed detection device of the present invention is incorporated is not limited to the railway vehicle bearing device of the present embodiment, and can be applied to, for example, an automobile bearing device.

It is a fragmentary sectional view which shows the bearing apparatus for rail vehicles in which the rotational speed detection apparatus which is one Embodiment of this invention is integrated. It is sectional drawing which shows the rotational speed detection apparatus of FIG. It is a top view which shows the rotational speed detection apparatus of FIG. It is a fragmentary sectional view which shows the conventional railway vehicle bearing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Railway vehicle bearing apparatus 11 Axle 12 Axle box 13 Double row tapered roller bearing 28 Encoder (rotating member)
32 Rotational speed detection device 36 Case 37 Lid 41 Rotational speed detection element 46 Side 43 Temperature detection element 44 Vibration detection element

Claims (3)

A rotation speed detection device comprising: a rotation speed detection element that detects a rotation speed of a rotation member; a housing that houses the rotation speed detection element and has an opening; and a lid that closes the opening of the housing;
In the side part of the housing located between the rotating member and the rotational speed detecting element, the thickness of the part facing the rotational speed detecting element is formed to be thinner than the thickness of the part to which the lid is attached. A rotational speed detection device characterized by that.   The rotation speed detection device according to claim 1, further comprising at least one of a temperature detection element and a vibration detection element.   The rotational speed detection device according to claim 2, wherein the rotational speed detection element is disposed on a side surface side of the casing from the at least one of the temperature detection element and the vibration detection element.

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