JP2005227000A - Optical rotation sensor and bearing with rotation sensor using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical rotation sensor in which the surface of a cord wheel is hardly fogged and reductions in detectability due to fogging hardly occur even when it is used in temperature-changing and humid environments and to provide a bearing with a rotation sensor provided with the same. <P>SOLUTION: The optical rotation sensor 11 is achieved by applying a photocatalytic and super-hydrophilic coating 21 to a surface of the cord wheel 6 in which a lattice 7 is formed. A light source for emitting ultraviolet rays is used as a light source 10a for detection, or an ultraviolet light emitter for irradiating ultraviolet light to the photocatalytic and super-hydrophilic coating 21 is provided independently of the light source 10a for detection. By mounting the optical rotation sensor 11 to an anti-friction bearing 1, the bering A with the rotation sensor is constituted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical rotation sensor that can be used in a wide range of environments, and a bearing with a rotation sensor using the same.

There are magnetic and optical rotation sensors, and the optical rotation sensor has an advantage that the resolution is superior to that of the magnetic rotation sensor.
Optical rotation sensors include a reflective type and a transmissive type. A reflective optical rotation sensor has a light source and a light receiver mounted on a non-rotating body, the detection light emitted from the light source is reflected by a reflecting plate mounted on the rotating side, and the reflected light is received by the light receiver. (For example, Patent Document 1).
A transmissive optical rotation sensor senses a light source and a light receiving member that are opposed to a non-rotating body with a rotating transmissive plate interposed therebetween, and that the light received from the light source and transmitted through the transmissive plate is sensed by the light receiving member. Is.

Conventionally, as shown in Patent Documents 2 and 3, a sensor-equipped bearing in which an optical rotation sensor is provided on a rolling bearing has been proposed. If the bearing is provided with a sensor in this way, it is not necessary to separately attach a rotation sensor, and the assembly of the bearing-using device is simplified and space saving can be achieved.
JP 2000-121653 A JP-A-8-240605 JP 2003-166544 A

The optical rotation sensor needs to receive the reflection detection light reflected by the reflection plate and the transmission detection light transmitted through the transmission plate. However, when these optical rotation sensors are moved from a high temperature environment to a low temperature environment, or when used in a humid environment, fine water droplets form on the surface of the reflector or transmission plate, which becomes cloudy and normal reflection. There is a problem that light detection or transmitted light detection cannot be obtained and sensing cannot be performed.
For this reason, the optical rotation sensor has a disadvantage that the environment in which the optical rotation sensor can be used is limited while the resolution is superior to that of the magnetic rotation sensor.
A bearing with a rotation sensor is often used in an environment where humidity changes frequently or in a humid environment. In such a case, a magnetic rotation sensor must be used, and improvement in resolution is difficult.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an optical rotation sensor in which the code wheel surface is less likely to be cloudy even when used in an environment with a high temperature change or in a humid environment, and a detection deterioration due to fogging does not easily occur, and a bearing with a rotation sensor provided with the optical rotation sensor Is to provide.

According to a first aspect of the present invention, the optical rotation sensor of the present invention irradiates the code wheel with detection light on the code wheel provided with a grid arranged in the circumferential direction that makes the reflection or transmission of light different from other parts. In the optical rotation sensor having a light source and a light receiving body for detecting reflected light or transmitted light of the code wheel, a hydrophilic coating is applied to a surface of the code wheel provided with a lattice. The lattice may be a mark or a slit.
If the code wheel is provided with a hydrophilic coating, it is difficult for water vapor to form a water droplet and adhere to the surface of the code wheel. Therefore, even when used in an environment where the temperature changes frequently or in a humid environment, the surface of the code wheel is less likely to be fogged, and the decrease in detectability due to fogging is mitigated. Therefore, it can be used in a wide environment, and an excellent resolution by the optical rotation sensor can be obtained in a wide range of environments.

The hydrophilic coating is preferably a photocatalytic superhydrophilic coating. In that case, for example, the light source that emits ultraviolet light is used.
In the case of this configuration, since the code wheel is irradiated with ultraviolet rays during use, the hydrophilic coating of the code wheel can exhibit its photocatalytic super hydrophilicity. For this reason, while operating as an optical rotation sensor, the coating surface of the code wheel can exhibit photocatalytic superhydrophilicity.
Here, clouding occurs on the surface because water vapor is cooled on the surface and countless water droplets adhere, but on the superhydrophilic surface, water droplets are not formed, and a uniform water film is formed. Generation of cloudiness is prevented. A general photocatalytic superhydrophilic coating exhibits superhydrophilicity due to its photocatalytic action when irradiated with ultraviolet light having a wavelength shorter than 400 nm. Therefore, it is preferable to use ultraviolet light as the light source.

In the present invention, when the hydrophilic coating is a photocatalytic superhydrophilic coating, an ultraviolet light emitter that irradiates ultraviolet light to the hydrophilic coating of the code wheel may be provided separately from the light source. The ultraviolet light emitter is, for example, an ultraviolet light emitting diode.
When a light source that emits ultraviolet rays is used as the light source for detection, it is necessary to take a measure such as using a fluorescent material for the grid of the code wheel or using a light receiver capable of receiving ultraviolet rays. On the other hand, when an ultraviolet light emitter is provided separately from the rotation detection light source, the photocatalytic superhydrophilic coating can be applied to the photocatalytic superhydrophilic coating even if a light source that emits general visible light is used as the detection light source. Can be demonstrated. Therefore, it is possible to use a general light source for detection, a light receiver combined with the light source, or a sensor unit in which the light source for detection and the light receiver are combined as an integral part or unit. In addition, it is not necessary to use a fluorescent material, and an increase in cost can be avoided. Although an ultraviolet light emitter is required separately, it is only necessary to add a simple component such as an ultraviolet light emitting diode, so that the cost increase can be reduced by taking the light receiver and code wheel into consideration.

Another optical rotation sensor according to the present invention includes a code wheel in which gratings that make the light reflection or transmission state different from other parts are arranged in the circumferential direction, a light source that irradiates the code wheel with detection light, An optical rotation sensor having a light receiving body for detecting reflected light or transmitted light of the code wheel, wherein the light source emits ultraviolet light.
When a light source that emits ultraviolet light is used, it becomes easy to obtain super hydrophilicity and prevent fogging by applying a photocatalytic super hydrophilic coating to the code wheel as described above. Even if fogging occurs on the surface of the light source and photoreceptor not only on the surface of the code wheel, if the photocatalytic superhydrophilic coating is applied to the surface of the light source or photoreceptor, the photocatalytic superhydrophilic property is generated by the ultraviolet light of the light source. Is prevented, and a decrease in detectability due to fogging is prevented.

Still another optical rotation sensor according to the present invention includes a code wheel in which gratings that make the reflection or transmission of light different from other parts are arranged in the circumferential direction, and a light source that irradiates the code wheel with detection light. An optical rotation sensor having a light receiving body for detecting reflected light or transmitted light of the code wheel, wherein a surface of the code wheel provided with a lattice is provided with a water repellent coating.
In the case of this configuration, the water-repellent action prevents condensation water or environmental water from adhering to the surface of the code wheel, and mitigates a decrease in detectability caused by fogging of the code wheel surface.

Still another optical rotation sensor according to the present invention includes a code wheel in which gratings that make the reflection or transmission of light different from other parts are arranged in the circumferential direction, and a light source that irradiates the code wheel with detection light. And an optical rotation sensor having a light receiving body for detecting reflected light or transmitted light of the code wheel, and a member attached with the light source in contact with the surface of the code wheel and wiping the surface by rotating the code wheel. A collecting member is provided.
In the case of this configuration, with the rotation of the code wheel, the dew condensation water and the environmental water adhering to the surface of the code wheel are wiped off by the wiping member. Therefore, a decrease in detectability due to fogging of the code wheel surface is mitigated.

A bearing with a rotation sensor according to the present invention includes a bearing having a rotating wheel and a fixed ring that are rotatable with respect to each other, and the optical rotation sensor having any one of the above-described configurations according to the present invention. The code wheel is attached to the rotating wheel, and the light source and the photoreceptor are attached to a fixed wheel.
According to the bearing with the rotation sensor of this configuration, since the rotation sensor is attached to the bearing, it is not necessary to attach the rotation sensor separately, and the assembly to the bearing using device becomes easy. In addition, the optical rotation sensor of the present invention effectively exhibits the effect of preventing the decrease in detectability due to fogging, and the use of the bearing with the rotation sensor is less restricted by the environment. Therefore, it can be a bearing with a rotation sensor capable of obtaining the excellent resolution of the optical rotation sensor in a wide range of environments.

  In the bearing with a rotation sensor according to the present invention, the code wheel of the optical sensor may be of a reflective type. If it is a reflection type, the light source and the light receiver can be arranged on the same side with respect to the code wheel, and when the bearing with a rotation sensor is used, it is easy to make the whole compact.

In the bearing with a rotation sensor of the present invention, a bearing seal for sealing a bearing space between the rotating wheel and the fixed wheel may be attached to the rotating wheel, and the bearing seal may be used as the code wheel.
If the bearing seal is also used as a code wheel, the number of parts is reduced and it is easy to achieve compactness.

In the optical rotation sensor according to the first aspect of the present invention, since the hydrophilic coating is applied to the surface of the code wheel on which the grating is provided, the surface of the code wheel can be used even in an environment where the temperature changes frequently or in a humid environment. Is difficult to cloud and it is difficult to cause a decrease in detectability due to clouding. Thereby, the resolution which is the advantage can be exhibited in an extensive environment using an optical rotation sensor.
In particular, when the hydrophilic coating is a photocatalytic superhydrophilic coating and the light source emits ultraviolet light, or when another ultraviolet light emitter is provided, the photocatalytic superhydrophilicity is exhibited, An excellent anti-fogging action can be obtained, and an excellent detectability without fogging can be obtained even when used in an environment with many temperature changes or in a humid environment.

Since another optical rotation sensor according to the present invention uses a light source that emits ultraviolet light, a photocatalytic super-hydrophilic coating is applied to the code wheel, the light source, and the photoreceptor, etc., resulting in a decrease in detectability due to fogging. It can be difficult.
In another optical rotation sensor of the present invention, a water repellent coating is applied to the surface of the code wheel provided with a lattice, so that the water repellent effect provides a fog prevention effect, resulting in the code wheel surface being fogged. Decrease in detectability is prevented and it can be used in a wide range of environments.
Still another optical rotation sensor of the present invention is provided with a wiping member for wiping the surface by the rotation of the code wheel, so that the wiping action can prevent fogging and prevent a decrease in detectability due to fogging. Can be used in a wide range of environments.

  Since the bearing with the rotation sensor of the present invention is mounted with the optical rotation sensor of the present invention, the optical rotation sensor effectively prevents the deterioration of detectability due to fogging, and can be used in a wide range of environments. Thus, it is possible to provide a bearing with a rotation sensor that can obtain the excellent resolution of the optical rotation sensor.

  A first embodiment of the present invention will be described with reference to FIGS. 1 is a longitudinal sectional view of a bearing with a rotation sensor, FIG. 2 is an enlarged view of a portion V in FIG. 1, and FIG. 3 is a partial arrow view taken along the line WW in FIG.

In FIG. 1, this rotation sensor-equipped bearing A is obtained by attaching an optical rotation sensor 11 to a rolling bearing 1. The rolling bearing 1 has a plurality of rolling elements 4 interposed between raceway surfaces 2a and 3a of an inner ring 2 serving as a rotating ring and an outer ring 3 serving as a fixed ring. In this example, the rolling bearing 1 is a deep groove ball bearing, and the rolling element 4 is held by a cage 24.
The optical rotation sensor 11 is attached to one end of the rolling bearing 1, and the other end of the bearing space between the inner and outer rings 2 and 3 is sealed with a bearing seal 5. The bearing seal 5 is a contact seal attached to the outer ring 3, and the seal lip portion 5 a is in sliding contact with the outer peripheral surface of the inner ring 2.

The optical rotation sensor 11 includes a code wheel 6 attached to the inner ring 2 and a reflective sensor unit 10 attached to the outer ring 3 via an attachment member 20.
The code wheel 6 is formed of a ring-shaped disk facing in the axial direction, and is attached to the outer diameter surface of the inner ring 2 in a fitted state by a cylindrical portion 6a provided integrally with the inner diameter portion. As shown in FIG. 3, the code wheel 6 is provided with a large number of non-reflective portions 7 a at regular intervals along the circumferential direction, and a portion between the adjacent non-reflective portions 7 a becomes a reflective grating 7.

  The reflective sensor unit 10 includes a light source 10a and a light receiving body 10b that detects reflected light reflected by the code wheel 6 from the light emitted from the light source 10a. The light source 10a and the light receiving body 10b are provided. Are accommodated in a common case 10d. A light emitting diode or the like is used for the light source 10a, and a semiconductor light receiving element or the like is used for the light receiver 10b.

In this embodiment, a light emitter that emits ultraviolet light, such as an ultraviolet light emitting diode, is used as the light source 10a.
In that case, the light receiving body 10b may be capable of detecting ultraviolet light, and the light receiving body 10b is configured to receive visible light, and the grating 7 serving as a reflection portion in the code wheel 6 is made of fluorescent paint or fluorescent ink. It is good also as the part which apply | coated fluorescent substances, such as. The fluorescent material absorbs ultraviolet rays, converts them into wavelengths in the visible light range, and emits them again. A commercially available ultraviolet reflection sensor can be used as the reflective sensor unit 10 in which such a light source 10a is an ultraviolet light emitting diode and the photoreceptor 10b receives light in the visible light range.

  The surface of the code wheel 6 on which the lattice 7 is provided is provided with a hydrophilic coating 21 (FIG. 3B). The hydrophilic coating 21 is a photocatalytic superhydrophilic coating. Super-hydrophilicity is a property of not repelling water at all. Photocatalytic superhydrophilicity is a property whereby superhydrophilicity can be obtained by photocatalytic action. As such a photocatalytic superhydrophilic coating, a thin film in which an appropriate material is combined with a titanium oxide (TiO2) photocatalyst can be used. For example, a coating agent in which a photocatalyst such as a titanium oxide photocatalyst is combined with a silicone resin can be used for the hydrophilic coating 21.

  In FIG. 1, the attachment member 20 for attaching the reflective sensor unit 10 to the outer ring 3 may be of any configuration, but in this embodiment, as shown in FIG. 2, with the attachment member 20 and the code wheel 6, One end of the bearing space between the inner and outer rings 2 and 3 is sealed. As a structure for this sealing, the code wheel 6 also serves as a bearing seal, and a labyrinth seal r is formed between the mounting member 20 and the code wheel 6. The reflective sensor unit 10 is arranged outside the labyrinth seal r in the mounting member 20 with respect to the bearing space. A space in the attachment member 20 in which the reflective sensor unit 10 is disposed is a space formed in an annular shape by the code wheel 6 and the attachment member 20, and is sealed to the outside by a contact seal 48.

A specific shape example of the mounting member 20 will be described. The attachment member 20 includes a support cylinder 8 and a support ring 9. The supporting cylinder 8 includes a small-diameter cylindrical portion 8a and a large-diameter cylindrical portion 8b connected to the small-diameter cylindrical portion 8a via a stepped portion 8c. The small-diameter cylindrical portion 8a is fitted to the inner diameter surface of the outer ring 3. Installed. The support ring 9 has a U-shaped cross section, and is attached to the inner diameter surface of the large-diameter cylindrical portion 8b of the support cylinder 8 in a fitted state.
The reflective sensor unit 10 is attached to the inner surface of the front plate portion of the support ring 9 with respect to the attachment member 20 via the substrate 10c. The substrate 10c is a wiring substrate or the like.

A cylindrical flange 6b is provided at the outer peripheral edge of the code wheel 6, and a portion of the code wheel 6 extending from the vicinity of the outer peripheral edge to the outer periphery of the flange 6b is a stepped portion 8c of the supporting cylinder 8. The labyrinth seal r is formed by a non-contact sealing gap between the side face and the inner diameter face of the outer diameter side cylindrical portion of the support ring 9.
A contact seal 48 is provided on the outer surface of the inner diameter portion of the cord wheel 6 so as to be in sliding contact with the outer diameter surface of the inner diameter side cylindrical portion of the support ring 9. The contact seal 48 is sealed. Instead of being attached to the code wheel 6, the contact seal 48 may be attached to the support ring 9 and slidably contacted with the code wheel 6.

  In addition, although illustration is abbreviate | omitted, two reflection type sensor parts 10 may be installed in the arrangement direction of the grating | lattice 7 with an appropriate space | interval, and in that case, it becomes possible to determine a rotation direction besides a rotation speed. .

  According to the bearing A with a rotation sensor having this configuration, when the inner ring 2 rotates, the rotation is detected by the optical rotation sensor 11. In the optical rotation sensor 11, the light emitted from the light source 10 a of the reflective sensor unit 10 is reflected by the grating 7 by the rotation of the code wheel 6 and received by the light receiving unit 10 c, and generates a pulse every time the light is received. The rotation speed is detected by this pulse.

  Since the surface of the code wheel 6 on which the lattice 7 is formed is provided with the hydrophilic coating 21, it is difficult for water vapor to form a water droplet and adhere to the surface of the code wheel. Therefore, it is difficult for cloudiness to occur. In particular, in this embodiment, the hydrophilic coating 21 is a photocatalytic superhydrophilic coating, and the light source 10a emits ultraviolet light. Therefore, superhydrophilicity is obtained by photocatalytic action, and fogging is further less likely to occur. . Therefore, even when used in an environment where the temperature changes frequently or in a humid environment, the surface of the code wheel is less likely to be fogged, and the decrease in detectability due to fogging is mitigated. Therefore, it can be used in a wide environment, and an excellent resolution by the optical rotation sensor can be obtained in a wide range of environments.

  Here, clouding occurs on the surface because water vapor is cooled on the surface and countless water droplets adhere, but on the superhydrophilic surface, water droplets are not formed, and a uniform water film is formed. Generation of cloudiness is prevented. The photocatalytic superhydrophilic coating exhibits superhydrophilicity due to its photocatalytic action when irradiated with ultraviolet rays having a wavelength shorter than 400 nm. Therefore, it is preferable to use ultraviolet light as the light source.

  The photocatalytic superhydrophilic property will be described. In this embodiment, a thin film in which an appropriate material is combined with a titanium oxide photocatalyst is used as the hydrophilic coating 21, and this thin film exhibits the following properties. The contact angle with water on the surface of the thin film is initially several tens of degrees. However, when the ultraviolet ray is applied, the contact angle decreases and finally becomes 0 degree, and water is not repelled at all. That is, it becomes superhydrophilic. Further, for several tens of hours thereafter, the contact angle is maintained at about several degrees without being irradiated with ultraviolet rays. Moreover, even if the contact angle increases, the superhydrophilicity is restored by simply irradiating with ultraviolet rays again.

  In the optical rotation sensor 11, the code wheel 6 is irradiated with ultraviolet rays during use, and the photocatalytic superhydrophilic property of the photocatalytic superhydrophilic coating 21 is exhibited. For this reason, the coating surface of the code wheel 6 exhibits photocatalytic superhydrophilicity while operating as the optical rotation sensor 11. In addition, the super-hydrophilic property is maintained for a long time even when the ultraviolet irradiation is interrupted, and is recovered by being irradiated with the ultraviolet light again. Super hydrophilicity will always be maintained.

  Further, according to the bearing A with a rotation sensor having this configuration, since the optical rotation sensor 11 is attached to the bearing 1, it is not necessary to attach the optical rotation sensor 11 separately, and the assembly to the bearing using device is facilitated. Further, the optical rotation sensor 11 effectively exhibits the effect of preventing a decrease in detectability due to fogging, and the use of the bearing A with the rotation sensor is less restricted by the environment. Therefore, it can be set as the bearing A with a rotation sensor which can obtain the outstanding resolution of the optical rotation sensor 11 in a wide range of environments.

  In this embodiment, the lattice forming surface of the code wheel 6 and the reflective sensor unit 10 in the optical rotation sensor 11 are disposed in the annular space of the mounting member 20, and the bearing space is sealed by the labyrinth seal portion r. The outer space is sealed with a contact seal 48. For this reason, dust, water, and the like are difficult to enter the lattice forming surface of the code wheel 6 and the installation space of the reflective sensor unit 10, and rotation detectability is reduced or the reflective sensor unit 10 is damaged due to the intrusion of dust or water. It is prevented.

  4 to 7 each show a bearing with a rotation sensor according to another embodiment of the present invention. Among these, each embodiment of FIG.4 and FIG.5 changes the shape for ensuring the sealing performance of the attachment member 20 and the code wheel 6 with respect to 1st Embodiment shown in FIG. is there. Hereinafter, the same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  In the bearing B with a rotation sensor shown in FIG. 4, a large-diameter cylindrical portion 6 c extending inward of the bearing is integrally provided on the outer peripheral edge portion of the code wheel 6. Further, an inward flange portion 8 c is provided at the tip of the small diameter cylindrical portion 8 a of the supporting cylinder 8 in the mounting member 20, and the inward flange portion 8 c, the small diameter cylindrical portion 8 a, and the large diameter cylindrical portion 6 c of the code wheel 6. A labyrinth seal r is constituted by a gap portion facing each other. Other configurations and effects are the same as those of the first embodiment.

  A bearing C with a rotation sensor shown in FIG. 5 has a contact seal 49 made of rubber or the like attached to the outer peripheral edge of the code wheel 6, and this contact seal 49 slides on the inner peripheral surface of the small-diameter cylindrical portion 8 a in the supporting cylinder 8. It was configured to touch. In this embodiment, since the contact seal 49 is provided, the rotational torque increases, but the sealing performance is improved. Other configurations and effects are the same as those of the first embodiment.

  In a bearing D with a rotation sensor shown in FIG. 6, a code wheel 6 used also as a bearing seal is integrated with a ring-shaped cored bar 36 and the cored bar 36 in the same manner as a general contact bearing seal with a cored bar. The rubber-like elastic bodies 37 and 38 are provided. The lattice 7 (FIG. 3) in the code wheel 6 is provided on the surface of the cored bar 36, and the surface on which the lattice 7 of the code wheel 6 is formed is a hydrophilic coating 21 (see FIG. (Not shown).

  A rubber-like elastic body 37 integrated with the inner diameter portion of the core metal 36 is fitted into a seal attachment groove 39 provided on the outer diameter surface of the inner ring 2, and the code wheel 6 is attached to the inner ring 2 by this fitting. . The rubber-like elastic body 37 on the inner diameter side serves as an attachment means for the seal attachment groove 39, and as shown in an enlarged view in FIG. Is also slidably contacted with the outer peripheral surface, and also serves as a sealing means for the outside of the installation space of the reflective sensor unit 10. The rubber-like elastic body 38 integrated with the outer diameter portion of the core metal 36 is in sliding contact with the inner diameter surface of the small diameter cylindrical portion 8a of the supporting cylinder 8 fitted to the inner diameter surface of the outer ring of the mounting member 20, and the bearing space. Seal.

  In the case of this configuration, the sealing performance of the bearing can be improved with a simple and compact configuration. Other configurations and effects are the same as those of the first embodiment.

  The embodiment shown in FIG. 7 is different from the embodiment shown in FIG. 6 in that a rubber-like elastic body 38 provided on the outer diameter side of the cored bar 36 in the code wheel 6 also serving as a bearing seal is replaced with a seal groove provided on the inner diameter surface of the outer ring 3. 40 is brought into contact with the vicinity. In the case of this configuration, the mounting member 20 is an integral part and is fitted to the outer diameter surface of the outer ring 3 for mounting. Other configurations are the same as those of the embodiment shown in FIG.

  FIG. 8 shows still another embodiment of the present invention. In the first embodiment shown in FIGS. 1 to 3, the bearing A ′ with a rotation sensor of this embodiment is different from the light source 10 a for detection of the reflective sensor unit 10 in the photocatalytic superhydrophilic coating of the code wheel 6. An ultraviolet light emitter 41 that irradiates ultraviolet rays to the hydrophilic coating 21 made of is provided. The ultraviolet light emitter 41 is, for example, an ultraviolet light emitting diode. The ultraviolet light emitter 41 is arranged at a position away from the light source 10a for detection in the circumferential direction of the code wheel 6, for example, 180 ° away. The detection light source 10a and the light receiver 10b of the reflective sensor unit 10 emit and receive visible light, and the grating 7 (FIG. 3) of the code wheel 6 is also used for reflection of visible light. . Other configurations in this embodiment are the same as those in the first embodiment.

As in the first embodiment, when a light source that emits ultraviolet light is used as the light source 10a for detection, a fluorescent material is used for the grating 7 of the code wheel 6, or the light receiver 10b can receive ultraviolet light. It is necessary to take measures such as using
On the other hand, when the ultraviolet light emitter 41 is provided separately from the rotation detection light source 10a as in this embodiment, even if a light source that emits general visible light is used as the detection light source 10a, The photocatalytic superhydrophilic coating 21 can exhibit its photocatalytic superhydrophilicity. Accordingly, a general light source 10a for detection and a light receiving body 10b combined therewith, or a reflective sensor unit 10 in which the light source 10a for detection and the light receiving body 10b are combined as an integral part or unit should be used. It is not necessary to use a fluorescent material for the grid 7 of the code wheel 6, and an increase in cost can be avoided. Although it is necessary to provide the ultraviolet light emitter 41 separately, since it is only necessary to add a simple part such as an ultraviolet light emitting diode, the cost increase is small when the light receiver 10b and the code wheel 7 are taken into consideration.

  4 to 7, as in the embodiment of FIG. 8, the photocatalytic superhydrophilic coating of the code wheel 6 is provided separately from the light source 10 a for detection of the reflective sensor unit 10. An ultraviolet light emitter 41 that irradiates the hydrophilic coating 21 with ultraviolet light may be provided.

In each of the above embodiments, the hydrophilic coating 21 is applied. Alternatively, a water-repellent coating may be applied to the surface of the code wheel 6 on which the lattice 7 is formed. In that case, the water repellency of the coating surface prevents the condensation water and the environmental water from adhering, and the effect of suppressing the occurrence of fogging is obtained. As the water-repellent coating, fluorine-based or silicone-based coatings can be used.
Further, the hydrophilic coating 11 and the water repellent coating are preferably applied not only to the surface on which the grid 7 of the code wheel 6 is formed, but also to the light emitting surface of the light source 10a and the light receiving surface of the photoreceptor 10b. A decrease in detectability is also prevented by fogging of the surfaces of the light source 10a and the photoreceptor 10b.

  In each of the above embodiments, the rotation sensor bearing 11 is of a reflective type, but may be of a transmissive type. In this case, as described above, instead of the unitized reflective sensor unit 10, a light emitter and a light receiver (both not shown) are arranged so as to sandwich the code wheel 6. The lattice 7 of the code wheel 6 is a slit that penetrates or a transparent portion.

  FIG. 9 thru | or 11 shows embodiment of the rolling bearing with a rotation sensor provided with the wiping member. Since the basic structure of the rotation sensor bearing F is substantially the same as that shown in FIGS. 1 and 2, the same reference numerals are given to the common parts, and the description thereof is omitted. In this embodiment, a plurality of columnar wiping members 12 are provided inside the support ring 9 of the mounting member 20 so as to sandwich the reflective sensor unit 10 in the circumferential direction. The tip end surface of the wiping member 12 is in sliding contact with the formation surface of the grid 7 of the code wheel 6. The wiping member 12 is made of various rubber materials, a porous member having high water absorption, a water absorbing polymer, or a highly water absorbing resin.

  In the case of this configuration, when the code wheel 6 rotates with the rotation of the inner ring 2, the formation surface of the lattice 7 in the code wheel 6 is always in sliding contact with the front end surface of the wiping member 12, and moisture adhering to the surface of the code wheel is wiped off. It is always wiped off by the take-up member 12. Therefore, fogging does not occur on the surface of the code wheel 6 where the lattice 7 is formed, and no dust is attached. Therefore, the surface on which the grating 7 is formed is always kept clean, detection of the detection light is not hindered, and rotation detection by the optical rotation sensor 11 is performed satisfactorily.

  Note that the wiping member 12 and the hydrophilic coating or water-repellent coating may be used in combination. By using such a combination, the effect of preventing fogging is further improved, and more reliable rotation detection and the like are performed.

  In this embodiment, each wiping member 12 has a cylindrical shape, but the wiping member 12 may have a bifurcated lip portion 12a formed at the tip, as shown in FIGS. These lip portions 12 a are configured such that the tips thereof are in contact with the formation surface of the grid 7 in the code wheel 6. The shape of the portion of the wiping member 12 on the base end side with respect to the lip portion 12a is a prismatic shape or the like. The material of the wiping member 12 can be the same material as that of the wiping member 12 in the embodiment shown in FIGS.

  Thus, when the lip | rip part 12a is provided in the wiping member 12, the wiping of the surface of the code wheel 6 is performed smoothly for the softness | flexibility of the lip | rip part 12a.

  In each embodiment in which these wiping members 12 are provided, not only the reflection type but also the transmission type optical rotation sensor 11 may be used. In the case of the transmission type, it is possible to remove water droplets generated in the slits serving as the lattice 7 in the code wheel 6.

In each of the above embodiments, the code wheel 6 and the reflective sensor unit 10 of the optical rotation sensor 11 are attached to the inner ring 2 and the outer ring 3 of the rolling bearing 1, but the code wheel 6 and the reflective sensor unit 10 Either one may be attached to the shaft, or the code wheel may be a part of the shaft.
FIGS. 14 and 15 show the respective embodiments in which the code wheel 6 is attached to the rotary shaft 30 into which the inner ring 2 of the rolling bearing 1 is fitted. 14 is an example in which the code wheel 6 and the reflective sensor unit 10 face each other in the axial direction. The bearing H with the rotational sensor in FIG. 15 includes the code wheel 6 and the reflective sensor. This is an example in which the portion 10 faces in the radial direction. The bearing I with a rotation sensor in FIG. 16 is an example in which a part of the rotating shaft 30 is a code wheel 6 and the code wheel 6 and the reflective sensor unit 10 are faced in the radial direction. 14 to 16, the rotation sensor-equipped bearings GI of the embodiments are the same as those of the first embodiment described above with reference to FIGS.

Items common to the embodiments of FIGS. 14 to 16 will be described. In each embodiment, the rolling bearing 1 is the same as the embodiment shown in FIG. Each of the code wheels 6 is a member in which gratings 7 are arranged in the circumferential direction so as to make the light reflection state different from other parts, and a hydrophilic coating 21 is applied to the surface on which the gratings 7 are provided. ing. The hydrophilic coating 21 is a photocatalytic superhydrophilic coating as in the first embodiment. Instead of the hydrophilic coating 21, a water repellent coating may be applied.
The reflective sensor unit 10 is provided with a light source and a light receiving body (not shown in FIGS. 14 to 16) in a common case, as in the first embodiment. A light emitting diode such as an ultraviolet light emitting diode is used as the light source, and a semiconductor light receiving element or the like is used as the photoreceptor.

Different configurations of the embodiments of FIGS. 14 to 16 will be described.
In the embodiment of FIG. 14, the code wheel 6 is formed as an L-shaped ring having a flange portion 6f on the outer periphery of the end opposite to the bearing of the cylindrical portion 6e fitted to the outer ring 2, and the inner surface of the flange portion 6f. Is provided with a lattice 7. The ring-shaped mounting member 20 to which the reflective sensor unit 10 is mounted has a stepped outer diameter surface portion attached at one end to a stepped inner diameter surface portion of the outer ring 2. The attachment member 20 faces the outer diameter surface and the inner surface of the collar portion of the L-shaped code wheel 6 having a cross-sectional shape through a gap, and the gap forms a labyrinth seal. By managing the relationship between the distance a between the outer ring end surface abutting surface of the mounting member 20 and the sensor surface and the distance b from the inner ring end surface abutting surface to the inner surface of the collar in the cylindrical portion of the code wheel 6, a reflective sensor An axial gap g between the portion 10 and the lattice 7 of the code wheel 6 is managed.

  In the example of FIG. 15, as in the embodiment of FIG. 14, the code wheel 6 has an L-shaped cross section and is in contact with the end surface of the inner ring 2 and is fitted to the rotary shaft 30, and the ring-shaped attachment member 20 is the outer ring. The grid 7 is provided on the outer diameter surface of the cylindrical portion of the code wheel 6, and the reflective sensor unit 10 is exposed on the inner diameter surface of the mounting member 20. Is provided. The radial gap g between the reflective sensor unit 10 and the grating 7 is the distance c of the inner diameter surface of the mounting member 20 with respect to the outer diameter surface of the rotating shaft 30 and the cylindrical portion of the code wheel 6 with respect to the outer diameter surface of the rotating shaft 30. And the distance d of the outer diameter surface.

  In the example of FIG. 16, the large diameter portion adjacent to the inner ring 2 on the rotating shaft 30 via the step surface is the code wheel 6, and the lattice 7 is provided on the outer periphery thereof. The reflective sensor unit 10 is attached to the attachment member 20 as in the embodiment of FIG. 15, and the attachment member 20 is attached to the inner diameter surface of the end portion of the outer ring 3.

  In each of the above embodiments, the inner ring 2 is a rotating wheel and the outer ring 3 is a fixed ring. Conversely, the inner ring 2 may be a fixed ring and the outer ring 3 may be a fixed ring. In that case, the reflective sensor unit 10 or the individual light source 10 a and the light receiver 10 b are attached to the inner ring 2, and the code wheel 6 is attached to the outer ring 3. The bearing with a rotation sensor of the present invention can also be applied to a sliding bearing.

It is a longitudinal section showing a bearing with a rotation sensor concerning a 1st embodiment of this invention. It is an enlarged view of the V section in FIG. FIG. 3 is a partially reduced arrow view of the WW line of FIG. 2. It is a partial longitudinal cross-sectional view of the bearing with a rotation sensor which concerns on other embodiment of this invention. It is a fragmentary longitudinal cross-sectional view of the bearing with a rotation sensor which concerns on further another embodiment of this invention. (A) The partial longitudinal cross-sectional view of the bearing with a rotation sensor which concerns on further another embodiment of this invention, (B) is the elements on larger scale of the same figure (A). It is a fragmentary longitudinal cross-sectional view of the bearing with a rotation sensor which concerns on further another embodiment of this invention. It is a longitudinal cross-sectional view of the whole bearing with a rotation sensor which concerns on further another embodiment of this invention. It is a fragmentary longitudinal cross-sectional view of the bearing with a rotation sensor which concerns on further another embodiment of this invention. FIG. 10 is a sectional view taken along line XX in FIG. 9. It is a YY arrow directional view in FIG. It is sectional drawing which shows the modification of the part corresponding to FIG. It is a ZZ line arrow line view in FIG. It is a fragmentary longitudinal cross-sectional view of the bearing with a rotation sensor which concerns on further another embodiment of this invention. It is a fragmentary longitudinal cross-sectional view of the bearing with a rotation sensor which concerns on further another embodiment of this invention. It is a fragmentary longitudinal cross-sectional view of the bearing with a rotation sensor which concerns on further another embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rolling bearing 2 ... Inner ring (rotating ring)
3. Outer ring (fixed ring)
6 ... Code wheel 7 ... Lattice 10 ... Reflective sensor unit 10a ... Light source 10b ... Photoreceptor 11 ... Optical rotation sensor 12 ... Wiping member AF ... Bearing with rotation sensor

Claims (9)

  A code wheel in which gratings that make the reflection or transmission of light different from other parts are arranged in the circumferential direction, a light source that irradiates the code wheel with detection light, and reflected or transmitted light of the code wheel is detected An optical rotation sensor having a light receiving body, wherein a hydrophilic coating is applied to a surface of the code wheel provided with a lattice.   2. The optical rotation sensor according to claim 1, wherein the hydrophilic coating is a photocatalytic superhydrophilic coating, and the light source emits ultraviolet light.   2. The optical rotation sensor according to claim 1, wherein the hydrophilic coating is a photocatalytic superhydrophilic coating, and an ultraviolet light emitter that irradiates ultraviolet light to the hydrophilic coating of the code wheel is provided separately from the light source. .   A code wheel in which gratings that make the reflection or transmission of light different from other parts are arranged in the circumferential direction, a light source that irradiates the code wheel with detection light, and reflected or transmitted light of the code wheel is detected An optical rotation sensor having a light receiving body that emits ultraviolet light as the light source.   A code wheel in which gratings that make the reflection or transmission of light different from other parts are arranged in the circumferential direction, a light source that irradiates the code wheel with detection light, and reflected or transmitted light of the code wheel is detected An optical rotation sensor comprising: a light receiving body that performs a water-repellent coating on a surface of the code wheel provided with a lattice.   A code wheel in which gratings that make the reflection or transmission of light different from other parts are arranged in the circumferential direction, a light source that irradiates the code wheel with detection light, and reflected or transmitted light of the code wheel is detected In the optical rotation sensor having a light receiving body, an optical type characterized in that a member to which the light source is attached is provided with a wiping member that contacts the surface of the code wheel and wipes the surface by rotation of the code wheel. Rotation sensor.   A bearing having a rotating wheel and a fixed wheel that are rotatable with respect to each other, and the optical rotation sensor according to any one of claims 1 to 6, wherein the code wheel is attached to the rotating wheel, and the fixed wheel is attached. A bearing with a rotation sensor to which the light source and the photoreceptor are attached.   The bearing with a rotation sensor according to claim 7, wherein the code wheel of the optical sensor is of a reflective type. The rotation sensor according to claim 7 or 8, wherein the bearing is a rolling bearing, and a bearing seal that seals a bearing space between the rotating wheel and the fixed ring is attached to the rotating wheel, and the bearing seal is used as the code wheel. bearing.

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