JP4091885B2 - Bearing abnormality detection device, bearing abnormality detection method, image forming apparatus, and disk drive device - Google Patents

Description

  The present invention relates to a bearing abnormality detection device, a bearing abnormality detection method, an image forming apparatus, and a disk drive device, and more specifically, a bearing abnormality detection device that detects an abnormality of a bearing supporting a rotating body in a small, inexpensive, and highly accurate manner, The present invention relates to a bearing abnormality detection method, an image forming apparatus, and a disk drive apparatus.

  As bearings used in rotating devices such as image forming apparatuses, ball bearings, dynamic pressure bearings that use oil or air as fluids, etc. are used. Etc., abnormal bearings such as abnormal noise and inability to rotate may occur.

  In the case of ball bearings, bearing abnormalities may occur due to initial ball scratches or grease deterioration due to long-term use. In the case of a hydrodynamic bearing using oil as a fluid, the oil may deteriorate due to long-term use or use in a high temperature environment, and a bearing abnormality may occur. Further, in the case of a hydrodynamic bearing using air as a fluid, the shaft and the sleeve come into contact with each other at the time of starting and stopping, so that wear may occur and bearing abnormality such as inability to rotate may occur.

  These bearing abnormalities lead to a failure of a main body device such as an image forming apparatus in which the rotating device is used, resulting in a large loss for the user.

  For example, in an image forming apparatus such as an electrophotographic copying machine, a printer, and a facsimile machine, an optical deflector that rotates and scans a laser beam is used. The forming apparatus cannot perform image formation and cannot output an image to a recording sheet.

  In addition, when a bearing abnormality occurs in the disk drive motor of the hard disk device, data cannot be read, and the data stored on the disk is lost.

  In order to prevent such a user's loss, a bearing abnormality is detected in advance, and before the rotating device breaks down, parts replacement and data backup are performed to prevent a serious loss of the user. It becomes important.

  Conventionally, a state detecting means for detecting the state of the bearing of the motor, an abnormality determining means for determining whether or not the bearing is abnormal based on the state of the bearing detected by the state detecting means, and the abnormality A motor bearing monitoring device having an output means for outputting a discrimination result by the discrimination means has been proposed, and as the state detection means, an impedance detection means for detecting the impedance of the bearing, an acoustic sensor for detecting the sound generated by the bearing A temperature sensor that detects the temperature of a bearing has been proposed (see Patent Document 1).

  On the other hand, an electrophotographic recording apparatus using a laser writing apparatus such as a digital copying machine or a laser printer has recently become 20000 for an optical deflector as the printing speed increases and the pixel density increases. Optical deflectors using dynamic pressure bearings have been put into practical use in order to satisfy the required quality of long life, high durability, and low noise.

  As an optical deflector using a dynamic pressure bearing, for example, there is a dynamic pressure air bearing type optical deflector previously proposed by the present applicant (see Patent Document 2).

JP 2002-131188 A

JP 2002-169119 A

  However, in such a conventional technique, there is a need for improvement in detecting an initial abnormality of a bearing and an abnormality due to deterioration over time at low cost and with high accuracy.

  That is, in the prior art described in Patent Document 1, when the state of the motor bearing is detected by an impedance change, the bearing surface needs to be an electrical conductor, such as a ceramic bearing or a resin coating. Thus, when the bearing surface is made of a non-conductive material, not only cannot be applied, but an electrode for detecting impedance, an AC power source, a detection circuit, etc. are required, and the rotating device is complicated. In addition, there is a problem that an electric field applied to the excitation electrode for impedance detection becomes electrical noise and may cause malfunction of the apparatus. In addition, when detecting the state of the motor bearing by sound or vibration, an expensive sensor for detection is required in any case, and the signal detected by each sensor is amplified. An amplifier is also required, and there is a problem that the bearing abnormality detection device itself becomes large and expensive. Furthermore, when detecting the state of the motor bearing by temperature, there is a problem in that the detection accuracy deteriorates due to the temperature around the main unit where the device is used, and erroneous detection of a bearing abnormality occurs. It was.

  Further, in the prior art described in Patent Document 2, in an optical deflector using a hydrodynamic bearing, the bearing friction torque increases due to wear of the bearing surface due to start / stop, which may cause a start failure. The method for detecting a bearing abnormality based on the contact rotational speed is a method generally known as a dynamic pressure bearing abnormality detecting means, and is effective for initial inspection, but it is effective for bearing wear and the like. For the deterioration over time, the detection by the contact rotational speed is not an effective method.

  Therefore, the present invention is effective for deterioration over time such as bearing wear, and can be used for initial inspection such as shipping inspection, and can detect a bearing abnormality at low cost and with high accuracy. An abnormality detection device, a bearing abnormality detection method, an image forming apparatus, and a hard disk drive device are provided.

In view of this, the invention according to claim 1 provides a reference stop time as a reference stop time that is used as a criterion for determining a bearing abnormality when detecting whether or not the bearing is abnormal in a rotating device that is supported by a bearing and rotates a rotating body. Store in the storage means, measure the stop time from the specific rotation speed of the rotating body to the rotation stop by the stop time measuring means, and compare the measured stop time measured by the stop time measuring means and the reference stop time by the judging means By determining whether there is an abnormality in the bearing, it is possible to detect the bearing abnormality in a non-contact manner before the rotating device becomes non-rotatable with a simple configuration without using a large and expensive device such as a sensor. An object of the present invention is to provide a bearing abnormality detection device that detects the presence or absence of a bearing abnormality with high accuracy at a low cost and in a wide application range.
The bearing abnormality detection device includes a temperature detection unit that detects the temperature of the rotating device, the reference stop time storage unit stores the reference stop time according to the temperature of the rotating device, and the determination unit includes the reference stop time. Compare the reference stop time according to the temperature of the rotating device detected by the temperature detection means among the reference stop times stored in the storage means and the measurement stop time measured by the stop time measurement means to determine whether there is an abnormality in the bearing. Accordingly, an object of the present invention is to provide a bearing abnormality detection device that detects the presence or absence of a bearing abnormality with low cost and high accuracy even for a bearing having a large change in stop time characteristics due to temperature.

  According to a second aspect of the present invention, the rotating device includes speed control means for controlling the rotational speed of the rotating body using the speed detection signal, and the stop time measuring means rotates based on the speed detection signal of the speed control means. An object of the present invention is to provide a bearing abnormality detection device that measures the stop time by detecting the speed of the body and measures the stop time at low cost and with high accuracy and detects the presence or absence of a bearing abnormality with higher accuracy. Yes.

  According to a third aspect of the present invention, the stop time measuring means includes a rotation speed detection means for detecting the rotation speed of the rotating body of the rotating device, and the rotation speed detected by the rotation speed detection means is stopped from the specific rotation speed. A time measuring means for measuring the stop time until the stop time measuring means with a component that can be equipped from the beginning or can be easily equipped on the rotating device or the main body device in which the rotating device is used. It is an object of the present invention to provide a bearing abnormality detection device that detects the presence or absence of a bearing abnormality more easily and inexpensively.

  According to a fourth aspect of the present invention, the rotational speed detecting means receives the light reflected by the polygon mirror of the rotating body and the light emitting means for emitting light to the polygon mirror formed on the rotating body of the rotating device. A light receiving means for outputting a signal; and a signal converting means for converting a light receiving signal output from the light receiving means into a rotational speed, so that when the rotating device is an optical deflector, the light deflection means It is an object of the present invention to provide a bearing abnormality detection device that simply and inexpensively detects the presence or absence of an abnormality in a bearing of an optical deflector.

  The invention according to claim 5 is such that the bearing abnormality detecting device is provided with a dynamic pressure bearing as a bearing and detects the presence or absence of abnormality of the dynamic pressure bearing, so that the start and stop are repeated over a long period of use. Bearing abnormality detection device that easily and inexpensively and accurately detects the presence or absence of an abnormality in a rotating device that uses a hydrodynamic bearing that may cause the bearing to wear and increase the friction torque of the bearing and cause startup failure. The purpose is to provide.

  The invention according to claim 6 is that the specific rotation speed is 2% or more and 20% or less of the rated rotation speed of the rotating device, so that the detection time of the stop time is limited to be short, and the measurement accuracy of the stop time is limited. An object of the present invention is to provide a bearing abnormality detection device that can detect the presence or absence of a bearing abnormality with higher accuracy.

The invention according to claim 7 is a stop time for measuring the time from the specific rotation speed of the rotating body to the rotation stop when detecting the presence or absence of abnormality of the bearing of the rotating device supported by the bearing and rotating the rotating body. It becomes a determination criterion of bearing abnormality according to the measurement processing step, the temperature detection processing step for detecting the temperature of the rotating body, the measurement stop time measured in the stop time measuring processing step, and the temperature of the rotating body detected in the temperature detection step. By performing a determination processing step that compares the reference stop time to determine whether there is an abnormality in the bearing, and without using a large and expensive device such as a sensor, the rotation device can be easily rotated before it becomes impossible to rotate. Another object of the present invention is to provide a bearing abnormality detection method that detects a bearing abnormality in a non-contact manner and detects the presence or absence of a bearing abnormality with high accuracy in a small, inexpensive and wide application range.

According to the eighth aspect of the present invention, the rotating polygon mirror of the optical deflector that rotationally drives the rotating polygon mirror that is rotatably supported by the bearing is irradiated with the beam emitted from the light source and scanned on the photosensitive member. Forming an electrostatic latent image, developing the electrostatic latent image with a developer to form a developer image, and transferring the developer image onto a sheet to form an image. By mounting the bearing abnormality detecting device according to any one of claims 1 to 6 as a bearing abnormality detecting device for detecting the presence of an abnormality in a bearing of an optical deflector as a rotating device. An object of the present invention is to provide an image forming apparatus in which parts can be replaced before the optical deflector becomes unrotatable.

The invention of claim 9, wherein, as the bearing abnormality detecting device for detecting the presence or absence of abnormality of the bearing in a disk drive motor for rotating the disk rotatably supported by a bearing, to one of claims 1 to 6 By installing the bearing abnormality detection device described above, it is possible to detect in advance the bearing abnormality of the disk drive motor as a rotating device and perform preliminary maintenance such as data backup before the disk drive motor becomes unable to rotate. An object of the present invention is to provide a disc drive motor that can be used.

A bearing abnormality detection device according to a first aspect of the present invention is a bearing abnormality detection device that detects the presence or absence of abnormality of the bearing of a rotating device that is supported by a bearing and rotates. Stop time measuring means for measuring a stop time from speed to rotation stop, reference stop time storage means for storing a reference stop time as a determination criterion for bearing abnormality, measurement stop time measured by the stop time measuring means, and A determination means for comparing the reference stop time to determine whether there is an abnormality in the bearing; and a temperature detection means for detecting the temperature of the rotating device , wherein the reference stop time storage means is a temperature of the rotating device. The reference stop time corresponding to the reference stop time is stored, and the determination means is the reference according to the temperature of the rotating device detected by the temperature detection means among the reference stop time stored in the reference stop time storage means. By comparing the measured measured stop time of the stop time and the stop time measuring device, by determining the presence or absence of abnormality of the bearing, it has achieved the above objects.

According to the above configuration, when detecting the presence or absence of abnormality of the bearing of the rotating device that is supported by the bearing and rotates the rotating body, the reference stop time that is a determination criterion of the bearing abnormality is stored in the reference stop time storage unit in advance. Then, the stop time from the specific rotation speed of the rotating body to the rotation stop is measured by the stop time measuring means, and the determination means compares the measured stop time measured by the stop time measuring means with the reference stop time to compare the bearing Since the presence or absence of abnormality is determined, it is possible to detect a bearing abnormality in a non-contact manner before the rotating device becomes non-rotatable with a simple configuration without using a large and expensive device such as a sensor. In addition, it is possible to detect the presence or absence of a bearing abnormality with high accuracy in a wide application range.
According to the above configuration, the bearing abnormality detection device includes the temperature detection unit that detects the temperature of the rotation device, and the reference stop time storage unit stores the reference stop time according to the temperature of the rotation device, and makes a determination. The means compares the reference stop time corresponding to the temperature of the rotating device detected by the temperature detection means among the reference stop times stored in the reference stop time storage means and the measurement stop time measured by the stop time measuring means, Therefore, the presence / absence of a bearing abnormality can be detected at low cost and with high accuracy even for a bearing having a large change in stop time characteristics due to temperature.

  In this case, for example, as described in claim 2, the rotating device includes a speed control unit that controls a rotation speed of the rotating body using a speed detection signal, and the stop time measuring unit includes the speed control unit. The stop time may be measured by detecting the speed of the rotating body based on the speed detection signal of the means.

  According to the above configuration, the rotating device includes the speed control unit that controls the rotation speed of the rotating body using the speed detection signal, and the stop time measuring unit is configured to detect the rotation body based on the speed detection signal of the speed control unit. Since the stop time is measured by detecting the speed, the stop time can be measured with low cost and high accuracy, and the presence or absence of a bearing abnormality can be detected with higher accuracy.

  For example, as described in claim 3, the stop time measurement unit includes a rotation speed detection unit that detects a rotation speed of the rotation body of the rotation device, and the rotation body that the rotation speed detection unit detects. And a time measuring means for measuring a stop time from the specific rotation speed to the rotation stop.

  According to the above configuration, the stop time measuring means includes the rotation speed detection means for detecting the rotation speed of the rotating body of the rotating device, and the speed of the rotating body detected by the rotation speed detection means from the specific rotation speed to the rotation stop. And the time measuring means for measuring the stop time. Therefore, the stop time measuring means is composed of components that can be equipped from the beginning or can be easily equipped on the rotating device or the main body device in which the rotating device is used. Therefore, it is possible to detect the presence or absence of a bearing abnormality even more easily and inexpensively.

  Further, for example, as described in claim 4, the rotation speed detection means is a light emitting means for emitting light to a polygon mirror formed on the rotating body of the rotating device, and is reflected by the polygon mirror of the rotating body. A light receiving unit that receives the received light and outputs a light reception signal; and a signal conversion unit that converts the light reception signal output from the light reception unit into a rotational speed.

  According to the above configuration, the rotational speed detecting means receives the light reflected by the polygon mirror of the rotating body and the light receiving means for emitting light to the polygon mirror formed on the rotating body of the rotating device and outputs a light reception signal. Since the light receiving means for outputting and the signal converting means for converting the light receiving signal output from the light receiving means into a rotational speed are provided, when the rotating device is an optical deflector, the bearing of the optical deflector The bearing abnormality detecting device for detecting the abnormality can be configured only on the main body side, and the presence or absence of abnormality of the bearing of the optical deflector can be detected easily and inexpensively.

  Further, for example, as described in claim 5, the bearing abnormality detection device may be configured such that the rotating device includes a dynamic pressure bearing as the bearing, and detects whether there is an abnormality in the dynamic pressure bearing. Good.

  According to the above configuration, the bearing abnormality detection device is configured such that the rotation device includes a dynamic pressure bearing as a bearing and detects the presence or absence of the abnormality of the dynamic pressure bearing. Therefore, it is possible to easily and inexpensively detect the presence or absence of abnormality of the rotating device using the hydrodynamic bearing, which may cause the start-up failure due to wear of the bearing and increase in the friction torque of the bearing.

  Further, for example, as described in claim 6, the specific rotation speed may be 2% or more and 20% or less of a rated rotation speed of the rotating device.

  According to the above configuration, since the specific rotation speed is 2% or more and 20% or less of the rated rotation speed of the rotating device, the detection time of the stop time is limited to be short and the measurement accuracy of the stop time is improved. It is possible to detect the presence or absence of an abnormality in the bearing with higher accuracy.

A bearing abnormality detection method according to a seventh aspect of the present invention is a bearing abnormality detection method for detecting the presence or absence of abnormality of the bearing of a rotating device that is supported by a bearing and rotates the rotating body , and is a specific rotational speed of the rotating body. A stop time measurement processing step for measuring the time from the rotation to the rotation stop, a temperature detection processing step for detecting the temperature of the rotating body, the measurement stop time measured in the stop time measurement processing step, and the rotating body detected in the temperature detection step The above-described object is achieved by performing a determination processing step for determining whether or not there is a bearing abnormality by comparing a reference stop time that is a criterion for determining a bearing abnormality according to the temperature of the bearing .

According to the above configuration, when detecting the presence or absence of abnormality of the bearing of the rotating device that is supported by the bearing and rotates the rotating body, the stop time measuring process that measures the time from the specific rotation speed of the rotating body to the rotation stop Step, temperature detection processing step for detecting the temperature of the rotating body, measurement stop time measured in the stop time measurement processing step, and reference stop as a bearing abnormality determination criterion according to the temperature of the rotating body detected in the temperature detection step And a determination processing step that compares the time to determine whether or not there is an abnormality in the bearing, so without using a large and expensive device such as a sensor, it is easy to detect the bearing abnormality before the rotating device becomes unable to rotate. Can be detected in a non-contact manner, and the presence or absence of a bearing abnormality can be detected with high accuracy in a small, inexpensive and wide range of applications.

According to an eighth aspect of the present invention, there is provided an image forming apparatus according to the present invention, wherein a beam emitted from a light source is irradiated onto a rotating polygon mirror of an optical deflector that rotationally drives a rotating polygon mirror that is rotatably supported by a bearing. In the image forming apparatus for scanning, forming an electrostatic latent image, developing the electrostatic latent image with a developer to form a developer image, and transferring the developer image onto a sheet to form an image. By mounting the bearing abnormality detecting device according to any one of claims 1 to 6 as a bearing abnormality detecting device for detecting the presence or absence of an abnormality in the bearing of the optical deflector, the above object is achieved. .

  According to the above configuration, the rotary polygon mirror of the optical deflector that rotationally drives the rotary polygon mirror that is rotatably supported by the bearing is irradiated with the beam emitted from the light source and scanned on the photoconductor, thereby electrostatic latent An image is formed, the latent electrostatic image is developed with a developer to form a developer image, and the developer image is transferred to a sheet of paper to form an image. Since the bearing abnormality detection device according to any one of claims 1 to 7 is mounted as a bearing abnormality detection device, the presence or absence of abnormality of the bearing of the optical deflector as the rotation device can be detected in advance. The parts can be replaced before the optical deflector becomes non-rotatable.

Disk drive motor of the invention of claim 9, wherein, in the disk drive motor for rotating the disk rotatably supported by a bearing, a bearing failure detection apparatus for detecting the presence or absence of abnormality in the bearing, claim from claim 1 By mounting the bearing abnormality detection device according to any one of 6 , the above object is achieved.

  According to the said structure, as a bearing abnormality detection apparatus which detects the presence or absence of abnormality of the said bearing of the disk drive motor which rotationally drives the disk supported rotatably with a bearing, It is in any one of Claims 1-7 Since the bearing abnormality detection device is installed, it is possible to detect in advance the bearing abnormality of the disk drive motor as a rotating device, and perform preliminary maintenance such as data backup before the disk drive motor becomes unable to rotate. be able to.

According to the bearing abnormality detection device of the first aspect of the invention, when detecting the presence or absence of abnormality of the bearing of the rotating device that is supported by the bearing and rotates the rotating body, the reference stop time that is a criterion for determining the bearing abnormality Is previously stored in the reference stop time storage means, the stop time from the specific rotation speed of the rotating body to the rotation stop is measured by the stop time measuring means, and the measurement stop time measured by the stop time measuring means and the reference are determined by the judging means. Compares the stop time to determine whether there is an abnormality in the bearing, so it can detect a bearing abnormality in a non-contact manner before the rotating device becomes non-rotatable with a simple configuration without using a large and expensive device such as a sensor. Therefore, it is possible to detect the presence or absence of a bearing abnormality with high accuracy in a small, inexpensive and wide application range.
According to the first aspect of the present invention, the bearing abnormality detection device includes temperature detection means for detecting the temperature of the rotation device, and the reference stop time storage means stores the reference stop time according to the temperature of the rotation device. Then, the determination means compares the reference stop time corresponding to the temperature of the rotating device detected by the temperature detection means among the reference stop times stored in the reference stop time storage means and the measurement stop time measured by the stop time measurement means. Thus, since it is determined whether or not there is an abnormality in the bearing, it is possible to detect the presence or absence of an abnormality in the bearing at a low cost and with high accuracy even for a bearing having a large change in stop time characteristics due to temperature.

  According to the bearing abnormality detection device of the second aspect of the present invention, the rotating device includes speed control means for controlling the rotational speed of the rotating body using the speed detection signal, and the stop time measuring means includes the speed control means. Since the speed of the rotating body is detected based on the speed detection signal and the stop time is measured, the stop time can be measured with low cost and high accuracy, and the presence or absence of a bearing abnormality can be detected with higher accuracy. it can.

  According to the bearing abnormality detecting device of the third aspect of the invention, the stop time measuring means includes the rotational speed detecting means for detecting the rotational speed of the rotating body of the rotating device, and the speed of the rotating body detected by the rotating speed detecting means. Is equipped with a time measuring means for measuring a stop time from a specific rotation speed to a rotation stop, so that the rotation device or the main body device used for the rotation device can be equipped from the beginning or easily equipped The stop time measuring means can be constituted by the elements, and the presence or absence of the bearing abnormality can be detected more easily and inexpensively.

  According to the bearing abnormality detecting device of the fourth aspect of the invention, the rotational speed detecting means is reflected by the light emitting means for emitting light to the polygon mirror formed on the rotating body of the rotating device and the polygon mirror of the rotating body. Light receiving means for receiving the received light and outputting a light receiving signal, and a signal converting means for converting the light receiving signal output from the light receiving means into a rotational speed, so that the rotating device is an optical deflector In this case, a bearing abnormality detection device for detecting an abnormality in the bearing of the optical deflector can be configured only on the main device side, and the presence or absence of an abnormality in the bearing of the optical deflector can be detected easily and inexpensively.

  According to the bearing abnormality detection device of the fifth aspect of the present invention, the bearing abnormality detection device is configured such that the rotating device includes a dynamic pressure bearing as a bearing and detects the presence or absence of abnormality of the dynamic pressure bearing. Repeated starting and stopping during use can cause wear of the bearing and increase the friction torque of the bearing, which can cause startup failure. Can be detected.

  According to the bearing abnormality detection device of the sixth aspect of the invention, since the specific rotation speed is 2% or more and 20% or less of the rated rotation speed of the rotation device, the detection time of the stop time is limited to be short. Therefore, the measurement accuracy of the stop time can be improved, and the presence / absence of abnormality of the bearing can be detected with higher accuracy.

According to the bearing abnormality detection method of the invention described in claim 7, when detecting the presence or absence of abnormality of the bearing of the rotating device that is supported by the bearing and rotates the rotating body, from the specific rotation speed of the rotating body to the rotation stop. The stop time measurement processing step for measuring the time of the above, the temperature detection processing step for detecting the temperature of the rotating body, the measurement stop time measured in the stopping time measurement processing step, and the temperature of the rotating body detected in the temperature detection step And a determination processing step for determining the presence or absence of a bearing abnormality by comparing with a reference stop time that is a criterion for determining a bearing abnormality according to the rotation, without using a large and expensive device such as a sensor. It is possible to easily detect a bearing abnormality without contact before the apparatus becomes non-rotatable, and to detect the presence or absence of a bearing abnormality with high accuracy in a small, inexpensive and wide application range.

According to the image forming apparatus of the eighth aspect of the present invention, the rotating polygon mirror of the optical deflector that rotationally drives the rotating polygon mirror that is rotatably supported by the bearing is irradiated with the beam emitted from the light source and the photosensitive member. The optical deflector that scans upward, forms an electrostatic latent image, develops the electrostatic latent image with a developer to form a developer image, and transfers the developer image onto a sheet to form an image. Since the bearing abnormality detecting device according to any one of claims 1 to 6 is mounted as a bearing abnormality detecting device for detecting the presence or absence of a bearing abnormality, the presence or absence of abnormality of the bearing of the optical deflector as the rotating device Can be detected in advance, and parts can be replaced before the optical deflector becomes non-rotatable.

According to the disc drive motor of the invention of claim 9, wherein, as a bearing failure detection apparatus for detecting the presence or absence of abnormality of the bearing in a disk drive motor for rotating the disk rotatably supported by a bearing, wherein claim 1 Since the bearing abnormality detection device according to any one of items 6 is mounted, it is possible to detect in advance a bearing abnormality of a disk drive motor as a rotating device, and before the disk drive motor becomes unable to rotate, data Pre-maintenance such as backup can be performed.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the accompanying drawings. The embodiments described below are preferred embodiments of the present invention, and thus various technically preferable limitations are given. However, the scope of the present invention is particularly limited in the following description. As long as there is no description which limits, it is not restricted to these aspects.

  1 to 5 are diagrams showing a first embodiment of a bearing abnormality detection device, a bearing abnormality detection method, an image forming apparatus, and a hard disk drive device according to the present invention. FIG. 1 shows a bearing abnormality detection according to the present invention. 1 is a block diagram of a main part of a bearing abnormality detecting device 1 to which a first embodiment of a device, a bearing abnormality detecting method, an image forming apparatus, and a hard disk drive device are applied.

  In FIG. 1, the bearing abnormality detection device 1 includes a stop time measurement unit 2, a reference stop time storage unit 3, a stop time comparison unit 4, a stop time comparison result output unit 5, and the like. A detection unit 6 and a time measurement unit 7 are provided. The bearing abnormality detection device 1 detects and outputs a rotation abnormality of the bearing of the rotating device 10.

  The rotating device 10 is, for example, a rotating polygon mirror device of an optical scanning device of a tandem type full color laser printer 100 as an image forming apparatus as shown in FIG.

  As shown in FIG. 2, the tandem type full-color laser printer 100 includes a plurality of image forming units 102Y that form yellow, magenta, cyan, and black color images along a conveyor belt 101 arranged in a horizontal direction. , 102M, 102C, and 102K are arranged at equal intervals, and the recording sheet of the conveying belt 101 is adjusted in timing by a registration roller 104 from a sheet feeding unit 103 arranged below the conveying belt 101. It will be fed later. In the full-color laser printer 100, a registration roller 104 and a belt charging charger 105 are disposed around the transport belt 101 on the upstream side of the image forming units 102Y, 102M, 102C, and 102K, and the image forming units 102Y, 102M, A belt separation charger 106, a charge removal charger 107, a cleaning unit 108, and the like are disposed in this order on the downstream side of 102C and 102K. Further, the full-color laser printer 100 is provided with a fixing unit 109 on the downstream side in the conveyance direction from the belt separation charger 106, and the recording paper fixed by the fixing unit 109 is discharged onto the paper discharge tray 111 by the paper discharge roller 110. .

  The image forming units 102Y, 102M, 102C, and 102K for the respective colors are centered on the photoreceptors 112Y, 112M, 112C, and 112K that are rotated in the clockwise direction with the same diameter, and around the process members according to the electrophotographic process. Charging chargers 113Y, 113M, 113C, 113K, optical scanning devices 114Y, 114M, 114C, 114K, developing units 115Y, 115M, 115C, 115K, transfer chargers 116Y, 116M, 116C, 116K, cleaning units 117Y, 117M, 117C. 117K etc. are arranged in order.

  In the full color laser printer 100, for example, in the full color mode (multiple color mode), the photoreceptors 112Y, 112M, 112C, and 112K that are uniformly charged by the charging chargers 113Y, 113M, 113C, and 113K, and yellow (Y) and magenta. (M), cyan (C), and black (K) based on the image signals of the respective colors, electrostatic latent images are formed by optical scanning of the light beams by the respective optical scanning devices 114Y, 114M, 114C, and 114K. The developing units 115Y, 115M, 115C, and 115K develop the electrostatic latent image with each color toner to form a toner image, and the transfer chargers 116Y, 116M, 116C, and 116K each color photoconductor 112Y, 112M, 112C, On the recording paper conveyed by electrostatically attracting the toner image on 112K onto the conveying belt 101 Superimposed by causing sequentially transferred to transfer the full-color image on a recording sheet. The full-color laser printer 100 conveys the recording paper on which transfer has been completed while being heated and pressurized by the fixing unit 109 to fix the full-color toner image on the recording paper, and discharges the recording paper on which the fixing of the full-color toner image has been completed. 110 is discharged onto the discharge tray 111. Further, in the full-color laser printer 100, in the black mode (monochrome mode), the photoconductors 112Y, 112M, and 112C and their process members are inoperative, and only the photoconductor 112K is based on the black image signal. Then, an electrostatic latent image is formed by optical scanning of the light beam by the optical scanning device 114K. The full-color laser printer 100 develops the electrostatic latent image on the photoconductor 112K with black toner by the developing unit 115Y to form a black toner image, which is electrostatically attracted and conveyed on the conveyor belt 101. Then, the image is fixed on a black monochrome image by being transferred onto a recording sheet, and then discharged.

  The optical scanning devices 114Y, 114M, 114C, and 114K include a common rotary polygon mirror 120. For example, the rotary polygon mirror 120 is shown in detail in FIG. 3 with respect to the optical scanning device 114Y. .

  That is, the optical scanning device 114Y includes a light source 131 that is a semiconductor laser, a coupling lens 132, an aperture 133, a cylindrical lens 134, a rotary polygon mirror 135 that is driven to rotate, lenses 136 and 137, a bending mirror 138, a mirror 139, and a lens 140. And other light scanning devices 114M, 114C, and 114K are configured in the same manner.

  The optical scanning device 114Y couples the beam of the divergent light beam emitted from the light source 131 to the subsequent optical system by the coupling lens 132, and the form of the coupled beam depends on the optical characteristics of the subsequent optical system. Accordingly, it can be a weak divergent light beam, a weak converging light beam, or a parallel light beam. When the beam that has passed through the coupling lens 132 passes through the opening of the aperture 133, the beam is blocked at the periphery of the light beam, is shaped, and enters the cylindrical lens 134 that is a latent image forming optical system. The cylindrical lens 134 has a power-less direction in the main scanning direction and a positive power in the sub-scanning direction. The cylindrical lens 134 focuses the incident beam in the sub-scanning direction, and near the deflecting reflection surface of the rotary polygon mirror 135. Collect light. The beam reflected by the deflecting and reflecting surface of the rotary polygon mirror 135 is deflected at a constant angular velocity as the rotary polygon mirror 135 rotates at a constant speed, and is transmitted through the two lenses 136 and 137 of the scanning optical system and bent. The optical path is bent by the mirror 138 and is condensed as a light spot on the photoconductor 112Y, and the surface of the photoconductor 112Y is scanned. Prior to scanning, the beam enters the mirror 139 and is focused on the light receiving element 141 by the lens 140. The full color laser printer 100 determines the writing start timing based on the output of the light receiving element 141.

  The rotating polygonal mirror device 120 is configured as shown in FIG. 4, and the rotating polygonal mirror device 120 is arranged on the lower surface of the cover case 151 to the optical housing 152 of the optical scanning devices 114Y, 114M, 114C, and 114K. Mounting reference surface 151a is formed. A housing 152 is fixed to the cover case 151. A bearing mounting portion 152a is formed at the center of the upper surface of the housing 152, and a fixed shaft 153 constituting a dynamic pressure air bearing is fixed.

  A groove 153a constituting a hydrodynamic air bearing is formed on the cylindrical surface of the fixed shaft 153. When the rotating body 154, which is the rotary polygon mirror 135, starts rotating, it is interposed between the rotating sleeve 155 and the fixed shaft 153. The air pressure of the formed bearing clearance is increased, and the rotating body 154 is supported in the radial direction (radial direction) without contact.

  A fixed portion 156 of the suction type magnetic bearing is fixed inside the fixed shaft 153, and the cap 157 and the stopper 158 are press-fitted and fixed to the inner cylinder portion of the fixed shaft 153 in the fixed portion 156 of the suction type magnetic bearing. In this way, it is sandwiched and fixed in the axial direction. In the center of the cap 157, a fine hole of about φ0.2 to φ0.5 is formed to attenuate the vertical vibration using the viscous resistance when air passes. Both the cap 157 and the stopper 158 are made of a non-magnetic material such as a stainless steel plate.

  The fixed portion 156 of the attraction type magnetic bearing is made of a ferromagnetic material in which a ring-shaped permanent magnet 159 magnetized in two poles in the rotation axis direction and a center circle smaller than the inner diameter of the ring-shaped permanent magnet 159 are formed. Similarly, the first fixed yoke plate 160 and the second fixed yoke plate 161 made of a ferromagnetic material in which a central circle smaller than the inner diameter of the ring-shaped permanent magnet 159 is formed. The first fixed yoke plate 160 and the second fixed yoke plate 161 sandwich the ring-shaped permanent magnet 159 in the axial direction, and the center circle of the first fixed yoke plate 160 and the center circle of the second fixed yoke plate 161. Is arranged and fixed so as to be coaxial with the rotation center axis. The material of the ring-shaped permanent magnet 159 is mainly a rare earth permanent magnet, and the fixed yoke plates 160 and 161 are steel plate materials.

  A printed circuit board 162 having a hole formed in the center is disposed on the upper surface of the housing 152, and a stator 163 is fitted and fixed to the outer diameter of the bearing mounting portion 152a of the housing 152. Since the printed circuit board 162 uses a conductive material such as an aluminum alloy for the housing 152, an eddy current does not flow through the housing 152 due to the influence of an alternating magnetic field caused by the rotation of the rotor magnet 164, and the loss of the motor does not increase. In addition, it is composed of an iron substrate. A Hall element 165 that is a position detection element for switching energization to the winding coil is mounted on the printed circuit board 162.

  The motor unit includes a rotor magnet 164 attached to the rotating body 154, a stator 163, a printed circuit board 162 to which the winding coil 163a is connected, a hall element 165 mounted on the printed circuit board 162, and the like.

  The stator 163 is formed by stacking silicon steel plates so that eddy current does not flow and iron loss does not increase.

  In the rotating body 154, a rotated member 166 is coupled to the outside of the rotating sleeve 155, and two-stage mirrors 166a and 166b are integrally formed in the axial direction.

  The rotating sleeve 155 is made of ceramic and has a long life by suppressing wear.

  The rotated member 166 is made of pure aluminum, and is integrally joined with the sleeve 166, and then a mirror is formed by mirror finishing.

  A rotor magnet 164 for a motor is bonded or press-fitted and fixed to the lower side of the rotated member 166, and a permanent magnet divided in the circumferential direction can be used as the rotor magnet 164, but bonding or press-fitting is easy. It is formed in a ring shape so that it can be performed. In this case, press-fitting the rotor magnet 164 can reduce the balance and vibration change due to temperature change, and is suitable as a motor for higher speed rotation.

  A through hole larger than the inner diameter of the dynamic pressure air bearing is formed at the upper end of the rotated member 166, and a closing member 167 having a linear expansion coefficient substantially equal to that of the rotated member 166 is press-fitted and fixed. The closing member 167 is formed in a disk shape, and a rotating portion 168 of an attraction type magnetic bearing is fixed to the closing member 167.

  An outer cylindrical surface that forms a magnetic gap is formed between the central circle of the first fixed yoke plate 160 and the central circle of the second fixed yoke plate 161 in the rotating portion 168 of the attractive magnetic bearing. The outer cylindrical surface is disposed so as to be coaxial with the rotation center axis. A permanent magnet or a steel-based ferromagnetic material is used for the rotating portion 168 of the attractive magnetic bearing.

  Since the rotating body 154 is rotated at a high speed, the balance correction is performed on the correction surfaces 155a and 164a at the two upper and lower portions of the rotating body 154 so that unbalanced vibration is at a very small level.

  The printed circuit board 162 is wired with a winding coil 163a that is a motor winding and a hall element 165, and is sequentially applied to the winding coil 163a that is a motor winding by a drive circuit 169 in accordance with a position detection signal of the hall element 165. The energization is switched to rotate the rotating body 154 to perform constant speed control.

  As described above, in the bearing abnormality detection device 1 of FIG. 1, for example, the rotary polygon mirror device 120 of the optical scanning devices 114Y, 114M, 114C, and 114K of the tandem type full-color laser printer 100 is applied as the rotation device 10 to be detected. .

  The rotating device 10 includes a speed control unit that performs speed control of the rotating body by PLL control or the like. In order to perform speed control, it is necessary to detect the speed of the rotating body. Configure a frequency generator with an FG (Frequency Generator) pattern, or use the detection signal of the Hall element 165, which is a position detection element of the rotating body 154, as described above, and the speed detecting unit The speed is detected and a speed detection signal is output. Although this speed detection signal varies depending on the configuration of the rotating device 10, it is converted into a pulse signal of 2 pulses to several tens of pulses per rotation, and the speed control unit phase-converts the speed detection signal of this pulse signal with the reference clock signal. In comparison, the speed of the rotating body is controlled by PLL control.

  Then, the stop time measuring unit (stop time measuring means) 2 of the bearing abnormality detection device 1 measures the time from the specific rotation speed of the rotating body of the rotating device 10 to the rotation stop, and the rotation of the stop time measuring unit 2 The speed detection unit (rotation speed detection means) 6 detects the rotation speed of the rotating body of the rotation device 10 by using, for example, a speed detection signal output from the speed detection unit of the rotation device 10. That is, the rotation speed detection unit 6 converts the measurement pulse period of the speed detection signal to a frequency and detects the number of rotations, that is, the rotation speed.

  The time measuring unit (time measuring means) 7 of the stop time measuring unit 2 can use a timer or the like mounted on a control device of a main body device (not shown) on which the rotating device 10 is mounted. The time until the rotating body of the rotating device 10 to be detected stops from the specific rotation speed is measured. The time measuring unit 7 may count the number of pulses of the rotational speed signal from the specific rotational speed of the rotating body to the stop.

  A reference stop time storage unit (reference stop time storage unit) 3 stores in advance a reference stop time as a reference for determining bearing abnormality, and a stop time comparison unit (determination unit) 4 is measured by the stop time measuring unit 2. The stop time until the rotating body of the rotating device 10 stops from the specific rotational speed is compared with the reference stop time of the reference stop time storage unit 3 to determine whether the rotating device 10 is normal or abnormal, and output a stop time comparison result. The determination result is output to the unit 5.

  The stop time comparison result output unit 5 can use, for example, a display unit or a sound output unit of the main body apparatus to which the rotating device 10 is applied, and displays or outputs the determination result of the stop time comparison b4.

  Next, the operation of the present embodiment will be described. The bearing abnormality detection device 1 detects the rotation speed of the rotating body of the rotating device 10, measures the stop time until the rotating body stops from a predetermined specific rotation speed, and sets the measured specific stop time in advance. The presence or absence of an abnormality in the bearing is determined by comparison with the reference stop time.

  That is, the bearing abnormality detecting device 1 detects the rotational speed of the rotating body of the rotating device 10 by the rotating speed detecting unit 6 of the stop time measuring unit 2 and detects the rotating body of the rotating device 10 detected by the rotating speed detecting unit 6. Is measured by the time measuring unit 7 of the stop time measuring unit 2 and output to the stop time comparing unit 4 as a measurement stop time.

  The stop time comparison unit 4 compares the measurement stop time input from the stop time measurement unit 2 with the reference stop time stored in the reference stop time comparison unit 3, determines the normality / abnormality of the rotating device 10, The determination result is output to the stop time comparison result output unit 5.

  The stop time comparison result output unit 5 can use, for example, a display unit or a sound output unit of the main body apparatus to which the rotating device 10 is applied, and displays or outputs the determination result of the stop time comparison unit 4.

  Then, the measurement stop time of the rotating body of the rotating device 10 is measured as shown in FIG. 5, and the stop time from the specific rotation speed is long in the non-defective rotating device 10 and short in the defective rotating device 10. The For example, the boundary between the non-defective product and the defective product is set as a reference stop time as shown in FIG. 5, and a bearing abnormality occurs if the measurement stop time measured by the stop time measuring unit 2 is longer or shorter than the reference stop time. Can be detected. As for the reference stop time, an operation test of the rotating device 10 is performed, a boundary between a non-defective product and a defective product is confirmed in advance, and the confirmed reference stop time is stored in the reference stop time storage unit 3.

  Then, the stop time comparison unit 4 is set in advance and stored in the reference stop time storage unit 3 as a measurement stop time from the specific rotation speed of the rotating body of the rotating device 10 detected by the stop time measuring unit 2 to the rotation stop. It is determined that the bearing is abnormal if the comparison result of the stop time is measured stop time <reference stop time.

  That is, the stop time of the rotating body of the rotating device 10 that is an initial abnormality and a bearing abnormality due to wear of the bearing surface due to long-term use is measured short, and a bearing abnormality can be detected in advance.

  The bearing abnormality detection device 1 can detect a bearing abnormality in a non-contact manner before the rotating device 10 becomes unable to rotate, does not require a large and expensive device such as a sensor, has a simple configuration, and has a wide range. Can be applied.

  Further, the bearing abnormality detection device 1 is applied to a rotating device 10 such as an optical deflector or a hard disk drive device, and the rotating device 10 has a rated rotational speed of several thousand revolutions / minute to several tens of thousands revolutions / minute. Used in.

  Therefore, when the rated rotational speed of the rotating device 10 is several thousand rotations, the bearing abnormality detecting device 1 can measure the time from the rated rotational speed to the rotation stop as it is, with the specific rotational speed as the rated rotational speed. Although it is good, when the rated speed is tens of thousands of revolutions, the bearing abnormality detection accuracy may be improved by setting the specific rotation speed, which is the measurement start speed, to 2 to 20% or less of the rated speed. . In particular, when the bearing of the rotating device 10 is a dynamic pressure bearing, wear tends to occur in the low-speed rotation region where the dynamic pressure effect is small, and changes that cause bearing abnormalities are likely to appear. In addition, since the accuracy deteriorates even if the rotational speed to be measured is too low, the accuracy of detecting a bearing abnormality is improved by setting the measurement starting rotational speed, which is a specific rotational speed, within a range of 2 to 20% of the rated rotational speed. be able to.

  And when making the measurement start rotation speed lower than the rated rotation speed, once the speed control unit is provided in the rotating device 10, from the state where the speed control is once performed at the measurement start rotation speed to the rotation stop. By measuring the stop time, it is possible to measure the stop time with high accuracy and to detect the bearing abnormality with high accuracy.

  As described above, the bearing abnormality detection device 1 according to the present embodiment is a reference that is a criterion for determining a bearing abnormality when detecting whether or not there is an abnormality in the bearing of the rotating device 10 that is supported by the bearing and rotates the rotating body. The stop time is stored in the reference stop time storage unit 3 in advance, the stop time from the specific rotation speed of the rotating body to the rotation stop is measured by the stop time measuring unit 2, and the stop time measuring unit 2 is measured by the stop time comparing unit 4. The measurement stop time measured in (1) and the reference stop time are compared to determine whether there is a bearing abnormality.

  Therefore, without using a large and expensive device such as a sensor, it is possible to detect a bearing abnormality in a non-contact manner before the rotating device 10 becomes non-rotatable with a simple configuration. It is possible to detect the presence or absence of a bearing abnormality with high accuracy.

  Further, the bearing abnormality detection device 1 and the rotation device 10 of the present embodiment include a speed control unit that controls the rotation speed of the rotating body using a speed detection signal, and the stop time measurement unit 2 includes the speed control unit. The stop time is measured by detecting the speed of the rotating body based on the speed detection signal.

  Therefore, it is possible to measure the stop time with low cost and high accuracy, and to detect the presence or absence of abnormality of the bearing with higher accuracy.

  Furthermore, in the bearing abnormality detection device 1 of the present embodiment, the stop time measurement unit 2 includes the rotation speed detection unit 6 that detects the rotation speed of the rotating body of the rotation device 10 and the rotation that the rotation speed detection unit 6 detects. It is assumed that the body speed includes a time measuring unit 7 that measures the stop time from the specific rotation speed to the rotation stop.

  Therefore, the stop time measuring means can be configured with components that can be equipped from the beginning or can be easily equipped with the rotation device 10 or the full-color laser printer 100 that is the main body device in which the rotation device 10 is used. It is possible to detect the presence or absence of a bearing abnormality at low cost.

  Further, in the bearing abnormality detection device 1 according to the present embodiment, the rotating device 10 is a rotary polygon mirror device 120 and includes a dynamic pressure bearing as a bearing, and detects whether there is an abnormality in the dynamic pressure bearing. I am going to do it.

  Therefore, it is easy and inexpensive to determine whether or not there is an abnormality in the rotating device 10 using the hydrodynamic bearing, which may cause the bearing to wear due to repeated start and stop in long-term use, resulting in increased bearing friction torque and start failure. And it can detect with high precision.

  Furthermore, in the bearing abnormality detection device 1 of the present embodiment, the specific rotation speed is 2% or more and 20% or less of the rated rotation speed of the rotation device 10.

  Therefore, it is possible to limit the detection time of the stop time to be short and improve the measurement accuracy of the stop time, and it is possible to detect the presence or absence of an abnormality in the bearing with higher accuracy.

  Further, the bearing abnormality detection device 1 according to the present embodiment detects from the specific rotation speed of the rotating body to the rotation stop when detecting the presence or absence of the bearing of the rotating device 10 that is supported by the bearing and rotates the rotating body. A stop time measurement processing step for measuring the time of the above, a determination processing step for comparing the measurement stop time measured in the stop time measurement step with a reference stop time as a determination criterion for bearing abnormality, and determining whether there is a bearing abnormality, , Has been implemented.

  Therefore, without using a large and expensive device such as a sensor, a bearing abnormality can be easily detected in a non-contact manner before the rotating device 10 becomes non-rotatable, and the bearing is small, inexpensive and highly accurate in a wide range of applications. The presence or absence of an abnormality can be detected.

  Furthermore, the bearing abnormality detection device 1 according to the present embodiment applies the beam emitted from the light source 131 to the rotary polygon mirror 135 of the rotary polygon mirror device 120 that rotates the rotary polygon mirror 135 that is rotatably supported by the bearing. Irradiate and scan on the photoconductors 112Y, 112M, 112C, and 112K to form an electrostatic latent image, develop the electrostatic latent image with a developer to form a developer image, and develop the developer image. The above-described bearing abnormality detection device 1 is mounted as a bearing abnormality detection device that detects the presence or absence of a bearing abnormality in the rotary polygonal mirror device 120 that is transferred to a sheet and forms an image.

  Therefore, it is possible to detect in advance whether there is an abnormality in the bearing of the rotary polygonal mirror device 120 as the rotary device 10, and it is possible to replace parts before the rotary polygonal mirror device 120 becomes unable to rotate.

  The above-described bearing abnormality detection device 1 is applied as a disk drive motor that rotationally drives a disk that is rotatably supported by a bearing, for example, a bearing abnormality detection device that detects the presence or absence of abnormality of the bearing of a disk drive motor of a hard disk. Then, a bearing abnormality of the disk drive motor as the rotating device 10 can be detected in advance, and prior maintenance such as data backup can be performed before the disk drive motor becomes unable to rotate.

  FIG. 6 is a block diagram of a main part of a bearing abnormality detecting device 20 to which the second embodiment of the bearing abnormality detecting device, the bearing abnormality detecting method, the image forming apparatus and the disk drive device according to the present invention is applied. This form corresponds to claim 4.

  The present embodiment is applied to a bearing abnormality detection device 20 similar to the bearing abnormality detection device 1 of the first embodiment, and the bearing abnormality detection device 1 of the first embodiment is combined with the bearing abnormality detection device 1 of the first embodiment. Similar components are denoted by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 6, the bearing abnormality detection device 20 includes a reference stop time storage unit 3, a stop time comparison unit 4, a stop time comparison result output unit 5, and the like similar to the bearing abnormality detection device 1 of the first embodiment. And a stop time measuring unit 21 that measures the stop time from the specific rotation speed of the rotating body of the rotating device 10 to the stop of rotation.

  The stop time measurement unit (stop time measurement unit) 21 includes a rotation speed detection unit (rotation speed detection unit) 22 and a time measurement unit (time measurement unit) 23 that detect the rotation speed of the rotating body, and detects the rotation speed. The unit 22 includes a light emitting unit (light emitting unit) 24, a light receiving unit (light receiving unit) 25, a light receiving signal / rotational speed converting unit (signal converting unit) 26, and the like.

  The rotating device 10 has the same configuration as that of the rotating device 10 according to the first embodiment, except that the rotating body includes a polygon mirror, and the polygon mirror is irradiated with light from the light emitting unit 25, so that the polygon is The light reflected by the mirror is received by the light receiving unit 25, and the light reception signal is output to the light reception signal / rotation speed conversion unit 26.

  The light reception signal / rotation speed conversion unit 26 converts the light reception signal input from the light reception unit 25 into a rotation speed.

  Then, the time measurement unit 23 measures the stop time from the specific rotation speed to the rotation stop of the rotating body of the rotating device 10 output by the light reception signal / rotation speed conversion unit 26, and the stop time as the measurement stop time. Output to the comparison unit 4.

  When the rotating device 10 is applied to the image forming apparatus, the rotating device 10 is a rotating polygonal mirror device (optical deflector) of the optical scanning device of the image forming apparatus, and the light emitting unit of the bearing abnormality detecting device 20 25 and the light receiving unit 26 can use a semiconductor laser light source which is a basic component of the optical scanning device of the image forming apparatus which is the main body device and a light receiving element of a timing signal for determining the writing start timing.

  When the rotational speed of the rotating device 10 is detected using the semiconductor laser light source and the light receiving element of the optical scanning device, a pulse signal corresponding to the number of surfaces of the rotating polygon mirror as the rotating device 10 per rotation is received by the light receiving unit 26. The measurement pulse period is converted into a rotation speed (rotation speed) by frequency conversion by the light reception signal / rotation speed conversion unit 26.

  Further, the time measuring unit 23 of the stop time measuring unit 21 is a timer mounted on a control device of a main body device (not shown) on which the rotating device 10 is mounted, similarly to the time measuring unit 7 of the first embodiment. The time until the rotating body of the rotating device 10 detected by the rotation speed detection unit 22 stops from the specific rotation speed is measured. The time measurement unit 23 may count the number of pulses of the rotation speed signal from the specific rotation speed of the rotating body to the stop.

  As described above, the bearing abnormality detection device 20 according to the present embodiment includes the rotation speed detection unit 22, the light emitting unit 24 that emits light to the polygon mirror formed on the rotating body of the rotating device 10, and the multiple surfaces of the rotating body. A light receiving unit 25 that receives light reflected by the mirror and outputs a light reception signal, and a reception signal / rotation speed conversion unit 26 that converts the light reception signal output from the light reception unit into a rotation speed are provided. .

  Therefore, when the rotation device 10 is an optical deflector, the bearing abnormality detection device 20 that detects an abnormality of the bearing of the optical deflector is configured only on the main body side, for example, a semiconductor laser of an optical scanning device of an image forming apparatus It can be configured by a light source, a light receiving element, and the like, and can detect the presence / absence of an abnormality in the bearing of the optical deflector easily and inexpensively.

FIG. 7 is a block diagram of the main part of a bearing abnormality detection device 30 to which the third embodiment of the bearing abnormality detection device, bearing abnormality detection method, image forming apparatus, and disk drive device of the present invention is applied. This form corresponds to claim 1 .

  The present embodiment is applied to a bearing abnormality detection device 30 similar to the bearing abnormality detection device 20 of the second embodiment, and the bearing abnormality detection device 20 of the second embodiment is combined with the bearing abnormality detection device 20 of the second embodiment. Similar components are denoted by the same reference numerals, and detailed description thereof is omitted.

  In FIG. 7, the bearing abnormality detection device 30 includes a stop time measurement unit 21, a stop time comparison unit 4, a stop time comparison result output unit 5 and the like similar to the bearing abnormality detection device 20 of the second embodiment. In addition, a temperature measuring unit 31 that detects the temperature of the rotating device 10 and a reference stop time storage unit 32 are provided.

  As described above, the stop time measurement unit 21 includes the rotation speed detection unit 22 that detects the rotation speed of the rotating body and the time measurement unit 23. The rotation speed detection unit 22 includes the light emitting unit 24, the light receiving unit 25, and A light reception signal / rotation speed conversion unit 26 and the like are provided.

  The rotating device 10 has the same configuration as that of the rotating device 10 according to the first embodiment, except that the rotating body includes a polygon mirror, and the polygon mirror is irradiated with light from the light emitting unit 25, so that the polygon is The light reflected by the mirror is received by the light receiving unit 25, and the light reception signal is output to the light reception signal / rotation speed conversion unit 26.

  The light reception signal / rotation speed conversion unit 26 converts the light reception signal input from the light reception unit 25 into a rotation speed.

  Then, the time measurement unit 23 measures the stop time from the specific rotation speed to the rotation stop of the rotating body of the rotating device 10 output by the light reception signal / rotation speed conversion unit 26, and the stop time as the measurement stop time. Output to the comparison unit 4.

  When the rotating device 10 is applied to an image forming apparatus, the rotating device 10 is a rotating polygonal mirror device of an optical scanning device of the image forming apparatus, and the light emitting unit 25 and the light receiving unit 26 of the bearing abnormality detecting device 20. Can use a semiconductor laser light source, which is a basic component of the optical scanning device of the image forming apparatus, which is the main body device, and a timing signal light receiving element for determining the writing start timing.

  When the rotational speed of the rotating device 10 is detected using the semiconductor laser light source and the light receiving element of the optical scanning device, a pulse signal corresponding to the number of surfaces of the rotating polygon mirror as the rotating device 10 per rotation is received by the light receiving unit 26. The measurement pulse period is converted into a rotation speed (rotation speed) by frequency conversion by the light reception signal / rotation speed conversion unit 26.

  Further, the time measuring unit 23 of the stop time measuring unit 21 is a timer mounted on a control device of a main body device (not shown) on which the rotating device 10 is mounted, similarly to the time measuring unit 7 of the first embodiment. The time until the rotating body of the rotating device 10 detected by the rotation speed detection unit 22 stops from the specific rotation speed is measured. The time measurement unit 23 may count the number of pulses of the rotation speed signal from the specific rotation speed of the rotating body to the stop.

  The temperature measuring unit (temperature detecting means) 31 is provided at or near the rotating device 10, detects the temperature of the rotating device 10, and outputs the temperature to the reference stop time storage unit 32.

  The reference stop time storage unit (reference stop time storage unit) 32 stores in advance a reference stop time as a reference for determining a bearing abnormality for each temperature of the rotating device 10. When the detected temperature is input, the reference stop time corresponding to the detected temperature is output to the stop time comparison unit 4.

  The stop time comparison unit 4 calculates the measurement stop time from the specific rotation speed of the rotating body of the rotating device 10 detected by the stop time measurement unit 21 to the rotation stop and the reference stop time input from the reference stop time storage unit 32. In comparison, if the comparison result of the stop time is measured stop time <reference stop time, it is determined that the bearing is abnormal.

  As described above, the bearing abnormality detection device 30 according to the present embodiment includes the temperature measurement unit 31 that detects the temperature of the rotating device 10, and the reference stop time storage unit 32 has a reference stop time corresponding to the temperature of the rotating device 10. The stop time comparing unit 4 stores the reference stop time and the stop time measuring unit 22 according to the temperature of the rotating device 10 detected by the temperature measuring unit 31 among the reference stop times stored in the reference stop time storage unit 32. The measured stop time is compared to determine the presence or absence of a bearing abnormality.

  Therefore, it is possible to detect the presence / absence of abnormality of the bearing with low cost and high accuracy even for a bearing having a large change in the stop time characteristic due to temperature.

  In other words, in a hydrodynamic bearing that uses oil as a fluid, the viscosity of the oil changes greatly with temperature, so the stop time also changes with temperature, the viscosity of the oil is high at low temperatures and the stop time is short, but the viscosity of the oil at high temperatures. Becomes lower and the stop time becomes longer. Therefore, the bearing abnormality can be accurately detected by changing the reference stop time corresponding to the measured temperature.

  The invention made by the present inventor has been specifically described based on the preferred embodiments. However, the present invention is not limited to the above, and various modifications can be made without departing from the scope of the invention. Needless to say.

  It can be applied not only to deterioration over time such as bearing wear but also to initial bearing inspection such as inspection before product shipment.

1 is a block diagram of a main part of a bearing abnormality detection device to which a first embodiment of a bearing abnormality detection device, a bearing abnormality detection method, an image forming apparatus, and a disk drive device according to the present invention is applied. The front schematic block diagram of the full-color laser printer to which the bearing abnormality detection apparatus of FIG. 1 is applied. FIG. 3 is a schematic perspective view of the optical scanning device in FIG. 2. FIG. 4 is a front sectional view of the rotary polygon mirror device of FIG. 3. The figure which shows the various examples of the stop time from the specific rotational speed of the rotating apparatus of FIG. FIG. 4 is a block diagram of a main part of a bearing abnormality detecting device to which a second embodiment of a bearing abnormality detecting device, a bearing abnormality detecting method, an image forming apparatus, and a disk drive device according to the present invention is applied. The block diagram of the principal part of the bearing abnormality detecting device to which the third embodiment of the bearing abnormality detecting device, bearing abnormality detecting method, image forming apparatus, and disk drive device of the present invention is applied.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bearing abnormality detection apparatus 2 Stop time measurement part 3 Reference | standard stop time memory | storage part 4 Stop time comparison part 5 Stop time comparison result output part 6 Rotational speed detection part 7 Time measurement part 10 Rotating device 20 Bearing abnormality detection apparatus 21 Stop time measurement part DESCRIPTION OF SYMBOLS 22 Rotation speed detection part 23 Time measurement part 24 Light emission part 25 Light reception part 26 Light reception signal / rotation speed conversion part 30 Bearing abnormality detection apparatus 31 Temperature measurement part 32 Reference | standard stop time memory | storage part 100 Full color laser printer 101 Conveyor belt 102Y, 102M, 102C , 102K Image forming unit 103 Paper feeding unit 104 Registration roller 105 Belt charging charger 106 Belt separation charger 107 Static neutralization charger 108 Cleaning unit 109 Fixing unit 110 Paper ejection roller 111 Paper ejection tray 112Y, 112M, 112C, 112K Photoconductor 113Y, 13M, 113C, 113K Charger charger 114Y, 114M, 114C, 114K Optical scanning device 115Y, 115M, 115C, 115K Developing unit 116Y, 116M, 116C, 116K Transfer charger 117Y, 117M, 117C, 117K Cleaning unit 120 Rotating polygon mirror device 131 Light source 132 Coupling lens 133 Aperture 134 Cylindrical lens 135 Rotating polygon mirror 136, 137 Lens 138 Bending mirror 139 Mirror 140 Lens 141 Light receiving element 151 Cover case 152 Housing 152a Bearing mounting portion 153 Fixed shaft 154 Rotating body 155 Rotating sleeve 155a Correction surface 155a Fixed part 157 Cap 158 Stopper 159 Permanent magnet 160 First fixed yoke plate 161 Second fixed Yoke plate 162 Printed circuit board 163 Stator 163a Winding coil 164 Rotor magnet 164a Correction surface 165 Hall element 166 Rotated member 166a, 166b Mirror 167 Closing member 168 Rotating part

Claims (9)

A bearing abnormality detection device that detects the presence or absence of abnormality of the bearing of a rotating device that is supported by a bearing and rotates a rotating body,
Stop time measuring means for measuring a stop time from a specific rotation speed of the rotating body to a rotation stop;
A reference stop time storage means for storing a reference stop time as a criterion for determining a bearing abnormality;
A determination means for comparing the measurement stop time measured by the stop time measurement means with the reference stop time to determine whether there is an abnormality in the bearing;
Temperature detecting means for detecting the temperature of the rotating device;
With
The reference stop time storage means stores the reference stop time according to the temperature of the rotating device,
The determination means includes the reference stop time according to the temperature of the rotating device detected by the temperature detection means among the reference stop time stored in the reference stop time storage means and the measurement stop measured by the stop time measurement means. A bearing abnormality detection device characterized by comparing the time to determine whether or not the bearing is abnormal.   The rotating device includes speed control means for controlling the rotation speed of the rotating body using a speed detection signal, and the stop time measuring means determines the speed of the rotating body based on the speed detection signal of the speed control means. 2. The bearing abnormality detecting device according to claim 1, wherein the stop time is detected and measured.   The stop time measuring means includes: a rotation speed detection means for detecting a rotation speed of the rotating body of the rotating device; and a stop from the specific rotation speed to the rotation stoppage of the rotation body detected by the rotation speed detection means. The bearing abnormality detecting device according to claim 1, further comprising: a time measuring unit that measures time. The rotational speed detecting means includes a light emitting means for emitting light to a polygon mirror formed on the rotating body of the rotating device;
A light receiving means for receiving light reflected by the polygon mirror of the rotating body and outputting a light reception signal;
A signal converting means for converting a light receiving signal output from the light receiving means into a rotation speed;
The bearing abnormality detection device according to claim 3, further comprising:   5. The bearing abnormality detection device according to claim 1, wherein the rotating device includes a dynamic pressure bearing as the bearing, and detects whether there is an abnormality in the dynamic pressure bearing. 6. Bearing abnormality detection device.   The bearing abnormality detection device according to any one of claims 1 to 5, wherein the specific rotation speed is 2% or more and 20% or less of a rated rotation speed of the rotation device. A bearing abnormality detection method for detecting whether or not there is an abnormality in the bearing of a rotating device that is supported by a bearing and rotates a rotating body,
A stop time measurement processing step for measuring a time from a specific rotation speed of the rotating body to a rotation stop;
A temperature detection processing step for detecting the temperature of the rotating body;
The measurement stop time measured in the stop time measurement processing step is compared with a reference stop time serving as a reference for determining a bearing abnormality according to the temperature of the rotating body detected in the temperature detection step to determine whether or not there is a bearing abnormality. A determination processing step to perform,
The bearing abnormality detection method characterized by implementing. The rotating polygon mirror of the optical deflector that rotates and supports the rotating polygon mirror that is rotatably supported by the bearing is irradiated with the beam emitted from the light source and scanned on the photosensitive member to form an electrostatic latent image, In the image forming apparatus for developing the electrostatic latent image with a developer to form a developer image, and transferring the developer image to a sheet to form an image.
An image forming apparatus comprising the bearing abnormality detecting device according to claim 1 as a bearing abnormality detecting device for detecting presence or absence of a bearing abnormality of the optical deflector . In a disk drive motor that rotationally drives a disk that is rotatably supported by a bearing ,
7. A disk drive motor comprising the bearing abnormality detecting device according to claim 1 as a bearing abnormality detecting device for detecting presence or absence of abnormality of the bearing .

Images