JP7377461B2 - Drive device and image forming device - Google Patents

Description

The present invention relates to a driving device and an image forming apparatus.

2. Description of the Related Art Conventionally, a drive device is known that includes a drive source and a drive transmission member that includes a cylindrical portion having internal teeth on its inner circumferential surface and transmits the driving force of the drive source to a driven object.

Patent Document 1 discloses that the drive device is made of a resin material, has an internal toothed portion in which the gear of the drive source meshes with the inner circumferential surface of the cylindrical portion of the drive transmission member, and is covered with the outer circumferential surface of the cylindrical portion. It is described that the drive body has an external toothed portion that engages with an external gear fixed to the shaft of the drive body.

However, there was a risk that the drive transmission member would be damaged.

In order to solve the above-mentioned problems, the present invention includes a drive source and a drive transmission member that includes a cylindrical portion having internal teeth on its inner circumferential surface and transmits the driving force of the drive source to a driven object. The drive device includes a deformation amount detection means for detecting deformation of the drive transmission member, and a control means for controlling the drive source based on a detection result of the deformation amount detection means. It is something.

According to the present invention, damage to the drive transmission member can be suppressed.

FIG. 1 is a schematic configuration diagram of a printer according to the present embodiment. An enlarged explanatory diagram of one of the four process units. FIG. 2 is a top view of a color drive device that drives Y, M, and C color photoreceptors and a developing roller. FIG. 2 is a perspective view of a collar drive device. FIG. 3 is a perspective view showing a photoreceptor gear train and a developing drive gear train. AA sectional view of FIG. 3. BB sectional view of FIG. 4. FIG. 3 is a perspective view showing a rear side plate, a unit-side developing gear train, a developing roller, and a photoreceptor. FIG. 3 is a schematic diagram showing how a color process unit is positioned in the apparatus. A schematic configuration diagram of the vicinity of the integrated developing internal gear and external gear. FIG. 3 is a diagram illustrating a development internal gear and external gear integrated gear. FIG. 3 is a schematic configuration diagram of the area surrounding the integrated gear with internal and external development teeth in the present embodiment. A process flow diagram for preventing damage to a developing gear with internal internal teeth and external teeth. The figure which shows an example of a warning display. FIG. 3 is a schematic configuration diagram showing a modification of the present embodiment.

Hereinafter, one embodiment of an electrophotographic printer (hereinafter simply referred to as "printer 100") will be described as an image forming apparatus to which the present invention is applied. First, the basic configuration of the printer 100 according to this embodiment will be described.
FIG. 1 is a schematic configuration diagram of a printer 100 according to this embodiment. The printer 100 includes four process units 26K, 26C, 26M, and 26Y for forming black, cyan, magenta, and yellow (hereinafter referred to as K, C, M, and Y) toner images. These use K, C, M, and Y toners of mutually different colors as image forming substances, but otherwise have the same configuration and are replaced when their service life is reached.

FIG. 2 is an enlarged explanatory diagram of one of the four process units 26K, 26C, 26M, and 26Y. The four process units 26K, 26C, 26M, and 26Y are the same except that they use different toner colors, so the subscripts (K, C, M, Y) indicating the toner colors used are omitted in FIG. are doing. As shown in FIG. 3, the process unit 26 includes a photoreceptor unit 10 that holds a drum-shaped photoreceptor 24 as a latent image carrier, a photoreceptor cleaning device 83, a static eliminator, and a charging device 25, and a developing unit 23. It is equipped with The process unit 26 as an image forming unit is removable from the main body of the printer 100, and consumable parts can be replaced at once.

The charging device 25 uniformly charges the surface of the photoreceptor 24, which is rotated clockwise in the figure by a driving means. The uniformly charged surface of the photoreceptor 24 is exposed and scanned by the laser beam L irradiated by the optical writing unit 27, and carries an electrostatic latent image for each color. This electrostatic latent image is developed into a toner image by a developing unit 23 using toner. Then, the image is primarily transferred onto the intermediate transfer belt 22.

The photoreceptor cleaning device 83 removes transfer residual toner adhering to the surface of the photoreceptor 24 after the primary transfer process. Further, the static eliminator removes residual charges on the photoreceptor 24 after cleaning. This charge removal initializes the surface of the photoreceptor 24 and prepares it for the next image formation.

The developing unit 23 includes a vertically long hopper section 86 that accommodates toner as a developer, and a developing section 87. In the hopper section 86 as a developer storage section, there are arranged an agitator 88 that is rotationally driven by a driving means, a toner supply roller 80 as a developer supplying member that is rotationally driven by the driving means vertically below the agitator 88, and the like. has been done. The toner in the hopper section 86 is agitated by the rotation of the agitator 88 and moves toward the toner supply roller 80 by its own weight. The toner supply roller 80 has a metal core and a roller portion made of foamed resin or the like coated on the surface of the metal core, and transfers the toner accumulated on the lower side inside the hopper portion 86 to the surface of the roller portion. Rotate while adhering.

Inside the developing section 87 of the developing unit 23, a developing roller 81 that rotates while contacting the photoreceptor 24 and the toner supply roller 80, a thinning blade 82 whose tip is brought into contact with the surface of the developing roller 81, and the like are disposed. There is. The toner adhering to the toner supply roller 80 in the hopper section 86 is supplied to the surface of the development roller 81 at the contact portion between the development roller 81 and the toner supply roller 80 . When the supplied toner passes through a contact position between the developing roller 81 and the layer thinning blade 82 as the developing roller 81 rotates, the layer thickness on the surface of the developing roller 81 is regulated. After the layer thickness has been regulated, the toner adheres to the electrostatic latent image on the surface of the photoreceptor 24 in the development region where the developing roller 81 and the photoreceptor 24 come into contact. This deposition develops the electrostatic latent image into a toner image.

Formation of such toner images is performed in each of the process units 26K, 26C, 26M, and 26Y, and toner images of each color are formed on the photoreceptors 24 of each of the process units 26K, 26C, 26M, and 26Y.

As shown in FIG. 1, an optical writing unit 27 is arranged vertically above the four process units 26K, 26C, 26M, and 26Y. The optical writing unit 27 as a latent image writing device optically scans each photoreceptor 24 in the four process units 26K, 26C, 26M, and 26Y with a laser beam L emitted from a laser diode based on image information. . By this optical scanning, electrostatic latent images for each color are formed on the photoreceptor 24. In this configuration, the optical writing unit 27 and the four process units 26K, 26C, 26M, and 26Y write K, C, M, and Y toners as visible images of different colors on the four photoreceptors 24, respectively. It functions as an image forming means for forming an image.

The optical writing unit 27 polarizes the laser beam L emitted from the light source by a polygon mirror rotationally driven by a polygon motor in the main scanning direction, and irradiates the photoreceptor 24 through a plurality of optical lenses and mirrors. . The optical writing unit 27 may be one that performs optical writing using LED light emitted from a plurality of LEDs of an LED array.

A transfer unit 75 as a belt device that moves the endless intermediate transfer belt 22 in a counterclockwise direction in the figure while stretching it is disposed vertically below the four process units 26K, 26C, 26M, and 26Y. has been done. In addition to the intermediate transfer belt 22, the transfer unit 75 includes a drive roller 76, a tension roller 20, four primary transfer rollers 74K, 74C, 74M, 74Y, a secondary transfer roller 21, a belt cleaning device 71, a cleaning backup roller 72, etc. It is equipped with

The intermediate transfer belt 22, which is a belt member and a transfer belt, is stretched by a drive roller 76, a tension roller 20, a cleaning backup roller 72, and four primary transfer rollers 74K, 74C, 74M, and 74Y, which are arranged inside the loop. It is suspended. Then, it is endlessly moved in the same direction by the rotational force of the drive roller 76 which is rotationally driven in the counterclockwise direction in the figure by the drive means.

The four primary transfer rollers 74K, 74C, 74M, and 74Y sandwich the endlessly moved intermediate transfer belt 22 between the photoreceptors 24K, 24C, 24M, and 24Y. This sandwiching forms four primary transfer nips for K, C, M, and Y where the front surface of the intermediate transfer belt 22 and the photoreceptors 24K, 24C, 24M, and 24Y come into contact.

A primary transfer bias is applied to each of the primary transfer rollers 74K, 74C, 74M, and 74Y by a transfer bias power source. As a result, a transfer electric field is formed between the electrostatic latent images on the photoreceptors 24K, 24C, 24M, and 24Y and the primary transfer rollers 74K, 74C, 74M, and 74Y. Note that a transfer charger, a transfer brush, or the like may be used instead of the primary transfer roller 74.

The Y color toner image formed on the surface of the photoreceptor 24Y of the process unit 26Y enters the above-mentioned primary transfer nip for Y as the photoreceptor 24Y rotates. In the Y primary transfer nip, the Y color toner image is primarily transferred from the photoreceptor 24Y onto the intermediate transfer belt 22 by the action of the transfer electric field and nip pressure. The intermediate transfer belt 22, onto which the Y color toner image has been primarily transferred in this way, passes through the primary transfer nip for M, C, and K as it moves endlessly. The M, C, and K color toner images are primarily transferred onto the Y color toner image in a superimposed manner. Through this overlapping primary transfer, a four-color toner image is formed on the intermediate transfer belt 22.

The secondary transfer roller 21 of the transfer unit 75 is disposed on the outside of the loop of the intermediate transfer belt 22, and holds the intermediate transfer belt 22 between it and the tension roller 20 on the inside of the loop. This nipping forms a secondary transfer nip in which the front surface of the intermediate transfer belt 22 and the secondary transfer roller 21 come into contact. A secondary transfer bias is applied to the secondary transfer roller 21 by a transfer bias power source. Due to this application, a secondary transfer electric field is formed between the secondary transfer roller 21 and the tension roller 20 which is connected to the ground.

Vertically below the transfer unit 75, a paper feed cassette 41 that accommodates a plurality of stacked recording sheets in the form of a bundle is disposed so as to be slidable in and out of the housing of the printer 100. In this paper feed cassette 41, a paper feed roller 42 is brought into contact with the topmost recording paper in a stack of paper, and by rotating this roller counterclockwise in the figure at a predetermined timing, the recording paper is fed. Feed it towards the paper feed path.

A registration roller pair 43 composed of two registration rollers is disposed near the end of the paper feed path. The registration roller pair 43 stops the rotation of both rollers as soon as the recording paper as a recording member sent out from the paper feed cassette 41 is sandwiched between the rollers. Then, the rotational drive is restarted at a timing that allows the sandwiched recording paper to be synchronized with the four-color toner image on the intermediate transfer belt 22 within the above-mentioned secondary transfer nip, and the recording paper is fed toward the secondary transfer nip.

The four-color toner image on the intermediate transfer belt 22, which is in close contact with the recording paper at the secondary transfer nip, is secondary-transferred all at once onto the recording paper under the influence of the secondary transfer electric field and nip pressure, and combined with the white color of the recording paper. , resulting in a full color toner image. When the recording paper on which the full-color toner image has been formed in this manner passes through the secondary transfer nip, it is separated from the secondary transfer roller 21 and the intermediate transfer belt 22 by the curvature. Then, the image is sent to a fixing device 40 as a fixing means via a post-transfer conveyance path.

The fixing device 40 is provided with a fixing roller 45 that includes a heat generating source 45a such as a halogen lamp, and a pressure roller 47 that rotates while contacting the fixing roller 45 with a predetermined pressure. A fixing nip is formed by the pressure roller 47. The recording paper fed into the fixing device 40 is held in the fixing nip with its unfixed toner image bearing surface brought into close contact with the fixing roller 45 . Then, the toner in the toner image is softened by the effects of heating and pressure, and a full-color image is fixed.

When the single-sided print mode is set, the recording paper ejected from the fixing device 40 is ejected out of the machine as it is. Then, it is stacked on a stack portion formed on the upper surface of the upper cover 56 of the casing.

Note that, after passing through the secondary transfer nip, the intermediate transfer belt 22 has residual transfer toner that has not been transferred to the recording paper attached thereto. This is cleaned from the belt surface by a belt cleaning device 71 that is in contact with the front surface of the intermediate transfer belt 22. A cleaning backup roller 72 disposed inside the loop of the intermediate transfer belt 22 backs up the cleaning of the belt by the belt cleaning device 71 from inside the loop.

3 is a top view of the color drive device 150 that drives the photoreceptors 24Y, 24M, and 24C of Y, M, and C colors and the developing rollers 81Y, 81M, and 81C, and FIG. 4 is a top view of the color drive device 150. FIG. 5 is a perspective view showing the photoreceptor gear train 50 and the developing drive gear train 15, FIG. 6 is a sectional view taken along line AA in FIG. 3, and FIG. 7 is a cross-sectional view taken along line BB in FIG. FIG.
The color drive device 150 includes a color photoconductor motor 51 that drives the photoconductors 24Y, 24M, and 24C, a color development motor 160 that drives the development rollers 81Y, 81M, and 81C, and a driving force of the color photoconductor motor 51. The photoreceptor gear train 50 transmits the driving force of the color developing motor 160 to each of the developing rollers 81Y, 81M, 81C, and the like.

The photoreceptor gear train 50 includes three photoreceptor gears 53Y, 53M, and 53C corresponding to each color, and an idler gear 52i for transmitting driving force from the M color photoreceptor gear 53M to the Y color photoreceptor gear 53Y. We are prepared. The photoreceptor gear train 50 is disposed between a drive bracket 162 that holds a color photoreceptor motor 51, a color developing motor 160, etc., and a gear bracket 163 that holds a developing internal gear with external teeth 155 and the like. (See Figure 7).

Each photoreceptor gear 53Y, 53M, 53C has a photoreceptor drive shaft 53aY, 53aM, 53aC, which is a spline shaft. Further, the photoreceptor gears 53C, 53M, and 53Y are large-diameter gears that are external gears having a larger diameter than the photoreceptors 24C, 24M, and 24Y, thereby reducing the influence of gear accuracy on images.
The rear end portions of the photoreceptors 24C, 24M, and 24Y have photoreceptor engaging portions 24aC, 24aM, and 24aY having spline holes into which photoreceptor drive shafts 53aC, 53aM, and 53aY are inserted and engaged. . By engaging the photoconductor drive shafts 53aC, 53aM, 53aY with the photoconductor engaging portions 24aC, 24aM, 24aY, the driving force of the color photoconductor motor 51 is transmitted to the photoconductors 24C, 24M, 24Y, and the photoconductor 24C, 24M, and 24Y are rotationally driven together with photoreceptor gears 53Y, 53M, and 53C.

The motor gear 51a of the color photoconductor motor 51 is engaged with a photoconductor gear 53C and a photoconductor gear 53M, and is connected to the photoconductor 24C and the photoconductor 24M via a photoconductor drive shaft 53aM of the photoconductor gear 53M. Drive is transmitted. Further, the driving force is transmitted from the photoreceptor gear 53M to the photoreceptor gear 53Y via the idler gear 52i, and the drive is transmitted to the photoreceptor 24Y via the photoreceptor drive shaft 53a of the photoreceptor gear 53Y.

The developing drive gear train 15 includes a developing gear with internal internal teeth and external teeth 155, an idler gear pulley 151, drive output gears 152Y, 152M, and 152C in Y, M, and C colors, and includes a gear bracket 163 and a rear plate of the device. 141.
As shown in FIG. 7, the developing internal toothed external toothed integral gear 155 has an internal toothed portion 155a and an external toothed portion 155b, and the internal toothed portion 155a is a motor gear formed on the motor shaft 160a of the color developing motor 160. It meshes with 164.

In this embodiment, the motor gear 164 is formed only in the range of the motor shaft 160a of the color developing motor 160 that meshes with the internal toothed portion 155a of the integral developing gear 155 with internal internal teeth and external teeth. In the range of the photoreceptor gear 53 in the tooth width direction (the range of the photoreceptor gear train 50 in the axial direction), the diameter of the motor shaft 160a is made smaller than the tip circle diameter of the motor gear 164. As a result, even if the diameter of the motor gear 164 of the color developing motor 160 is increased, the color drive device 150 does not become larger, and it is possible to achieve low noise and miniaturization of the drive device.

The development internal gear/external gear integral gear 155 is rotatably supported by a drive pin 163a fixed to a gear bracket 163. The idler gear part 151a of the idler gear pulley 151 and the driven gear part 152a of the M color drive output gear 152M are engaged with the external tooth part 155b of the development internal tooth external tooth integrated gear 155 (see FIG. 5).

The motor gear 164, the internal toothed portion 155a, the external toothed portion 155b, the idler gear portion 151a, and the M-colored drive output gear 152M may have helical teeth. By using helical teeth, the meshing ratio can be increased and meshing vibration and noise can be suppressed. Further, at this time, it is preferable that the helical teeth of the internal tooth portion 155a are twisted so that the direction of the thrust force generated during rotational driving is on the motor side. Specifically, when looking at the motor shaft from the axial direction from the developing roller side, when the direction of rotation of the motor shaft is counterclockwise, the helical teeth are twisted to the right, and when the direction of rotation of the motor shaft is clockwise, the helical teeth are twisted to the right. , the helical teeth are twisted to the left. That is, the helical teeth are twisted so that the developing roller side of the helical teeth is positioned downstream in the rotational direction from the motor side. As a result, a thrust force toward the developing roller side acts on the motor gear 164 during rotational driving, and the color developing motor 160 can be pressed against the drive bracket 162. Thereby, the posture of the color developing motor 160 can be maintained, and the occurrence of meshing vibrations and the like can be satisfactorily suppressed.

Further, it is desirable that the helical teeth of the external toothed portion 155b be twisted in a direction opposite to the thrust force of the internal toothed portion 155a, that is, such that the thrust force acts on the developing roller side. Specifically, the helical teeth of the external toothed portion 155b are twisted in the same direction as the motor gear 164, and the helical teeth of the internal toothed portion 155a are twisted in the opposite direction. As a result, the thrust force of the internal tooth portion 155a can be canceled by the thrust force of the external tooth portion 155b, and the developing internal tooth external tooth integrated gear 155 moves toward the drive motor and rotates while contacting the drive bracket 162. It is possible to prevent it from being driven. As a result, the development roller 81 can be rotationally driven without causing rotational unevenness by properly rotationally driving the developing internal-toothed external-toothed integrated gear 155.

Further, the development internal tooth external tooth integrated gear 155 has an external tooth portion 155b formed on the outer periphery of the internal tooth portion 155a of the cylindrical portion 1 in which internal teeth are formed on the inner periphery. Compared to the case where the gears and gears are arranged side by side in the axial direction, the length can be made shorter in the axial direction, and the device can be made smaller.

The drive output gears 152Y, 152M, and 152C of each color have the same shape and include a driven gear portion 152a, a pulley portion 152b, and a drive side coupling portion 152c having a spline hole (see FIG. 3). The idler gear pulley 151 has an idler gear portion 151a and a pulley portion 151b. The idler gear pulley 151 and the drive output gears 152Y, 152M, and 152C of each color are rotatably supported by a drive pin fixed to a drive bracket 162. In this way, by making the drive output gears 152Y, 152M, and 152C of each color the same shape, parts can be made common, and parts management costs can be reduced. Note that the drive output gear 152C and the drive output gear 152Y may be configured to include only the pulley portion 152b and the drive side coupling portion 152c.

A first timing belt 153 is wound around the pulley portion 151b of the idler gear pulley 151 and the pulley portion 152bY of the drive output gear 152Y. Further, a second timing belt 154 is wound around the pulley portion 152bM of the M color drive output gear 152M and the pulley portion 152bC of the C color drive output gear 152C. A V-belt or the like can be used as the first timing belt 153 and the second timing belt 154.

A first tightener 156 is in contact with a belt surface on the outer periphery of the first timing belt 153 to apply tension to the first timing belt 153. Further, a second tightener 157 is in contact with the outer circumferential belt surface of the second timing belt 154 to apply tension to the second timing belt 154 . Furthermore, by providing the first tightener 156 and the second tightener 157 in a swingable manner on the drive bracket 162 or the like, the tension from the first timing belt 153 and the second timing belt 154 can be managed to be constant.

The developing units of each color each have unit-side developing gear trains 180Y, 180M, and 180C. The unit side developing gear trains 180Y, 180M, 180C for each color include driven side couplings 181Y, 181M, 181C which are spline shafts, development input gears 182Y, 182M, 182C, development idler gears 183Y, 183M, 183C, and development output. It has gears 184Y, 184M, and 184C. The development input gears 182Y, 182M, 182C are provided coaxially with the driven side couplings 181Y, 181M, 181C, and the development output gears 184Y, 184M, 184C provided on the shaft of the development roller are connected to the development idler gears 183Y, 183M. , 183C.

The driving force of the color developing motor 160 is transmitted to the Y color developing unit 23Y via the internal and external developing gear 155, the idler gear pulley 151, the first timing belt 153, and the drive output gear 152Y. Then, the driving force of the color developing motor 160 is transmitted to the developing roller 81Y via the driven side coupling 181Y on the developing unit 23Y side, the developing input gear 182Y, the developing idler gear 183Y, and the developing output gear 184Y, and the developing roller 81Y rotates. drive

The driving force of the color developing motor 160 is transmitted to the developing unit 23M via the internal and external developing gear 155 and the drive output gear 152M. Then, the driving force of the color developing motor 160 is transmitted to the developing roller 81M via the driven side coupling 181M, the developing input gear 182M, the developing idler gear 183M, and the developing output gear 184M on the developing unit 23M side, and the developing roller 81M rotates. drive

The driving force of the color developing motor 160 is transmitted to the developing unit 23C via the internal and external developing gear 155, the drive output gear 152M, the second timing belt 154, and the drive output gear 152C. Then, the driving force of the color developing motor 160 is transmitted to the developing roller 81C via the driven side coupling 181C, the developing input gear 182C, the developing idler gear 183C, and the developing output gear 184C on the developing unit 23C side, and the developing roller 81C rotates. drive

In this embodiment, the gear that meshes with the motor gear 164 of the color development motor 160 is the internal tooth portion 155a of the development internal and external tooth integrated gear 155. Thereby, the meshing ratio with the motor gear 164 can be increased, and the occurrence of uneven rotation, noise, and vibration can be suppressed.

FIG. 8 is a perspective view showing the rear side plate 141, the unit side developing gear trains 180Y, 180M, 180C, the developing rollers 81Y, 81M, 81C, and the photoreceptors 24Y, 24M, 24C.
As shown in FIG. 8, photoreceptor drive shafts 53aY, 53aM, and 53aC pass through the rear plate 141 of the device. The tip end portions of the photoreceptor drive shafts 53aY, 53aM, and 53aC penetrating from the rear plate 141 enter into spline holes of the photoreceptor engaging portions 24aC, 24aM, and 24aY, and are drivingly connected.

Further, the drive side coupling portions 152cY, 152cM, and 152cC also penetrate the rear side plate 141. The drive-side couplings fit into the spline holes of the drive-side coupling portions 152cY, 152cM, and 152cC for driving connection.

Furthermore, positioning holes 142Y, 142M, and 142C are formed in the rear side plate 141 for positioning the process units 26Y, 26M, and 26C.

FIG. 9 is a schematic diagram showing how the color process units 26Y, 26M, and 26C are positioned in the apparatus.
As shown in FIG. 9, the color process units 26Y, 26M, 26C are equipped with positioning pins 26aY, 26aM, 26aC, and the positioning pins 26aY, 26aM, 26aC are connected to the positioning holes 142Y, 142M of the rear plate 141, 142C, the process units 26Y, 26M, and 26C are positioned in the apparatus main body.

FIG. 10 is a schematic diagram of the vicinity of the developing internal-toothed external-tooth integral gear 155.
As shown in FIGS. 9 and 10, when the process unit 26M is positioned in the apparatus main body, the positioning pin 26a of the process unit 26M is opposed to the developing gear 155 with internal and external teeth.

FIG. 11 is a diagram illustrating the development gear 155 with internal and external teeth.
As shown in FIG. 11(a), the developing internal-toothed external-toothed integrated gear 155, which is a drive transmission member, includes a cylindrical portion 1 having an external toothed portion 155b on the outer circumferential surface, an internal toothed portion 155a on the inner circumferential surface, and a shaft. A cylindrical shaft support part 3 having a shaft insertion hole 155c into which a drive pin 163a is inserted, one axial end of the cylindrical part 1 (end on the process unit side), and one end of the shaft support part 3. The cylindrical part 1 has a shape in which one end side of the cylindrical part 1 is closed.

Load torque is applied to the meshing portion between the external tooth portion 155b and the idler gear pulley 151, the meshing portion between the external tooth portion 155b and the driven gear portion 152a of the drive output gear 152M, and the meshing portion between the internal tooth portion 155a and the motor gear 164. is added. Since the tooth surfaces of the external teeth of the external tooth portion 155b and the internal teeth of the internal tooth portion 155a are inclined surfaces, the load torque applied to these tooth surfaces is in the circumferential direction and in the f1, f2, It acts in the radial direction as shown at f3.

As shown in FIG. 11(b), the idler gear pulley 151 and the driven gear portion 152a are engaged with each other on the upper side of the external toothed portion 155b, and the motor gear 164 is engaged with the lower side of the internal toothed portion 155a. Therefore, the radial load torques f1, f2, and f3 at each meshing portion are directed approximately downward, and a force that presses the cylindrical portion 1 downward is generated.

The development internal gear and external tooth integral gear 155 is made of a resin material with high sliding properties from the viewpoint of reducing meshing noise, but the resin material with high sliding properties has a relatively low bending elastic modulus. As a result, due to the radial load torques f1, f2, and f3 at each meshing portion as shown in FIG. 11(b), the connecting portion 2 is tilted with respect to the axial direction as shown by the dotted line in FIG. 11(a). As a result, the cylindrical portion 1 tends to tilt with respect to the axial direction.

In particular, if the developing roller as a driven body becomes difficult to rotate due to some problem and an abnormal load occurs, the load torques f1, f2, f3 in the radial direction at each meshing part will increase, and the cylindrical part 1 will move in the axial direction. It leans heavily against. When the cylindrical part 1 is tilted significantly with respect to the axial direction, uneven contact occurs in the meshing part between the external tooth part 155b and the internal tooth part 155a, where the tooth contact is concentrated in a part of the tooth width direction, and the tooth contact in the tooth width direction becomes uneven. Stress is concentrated in one part. In this embodiment, at the meshing portion between the internal tooth portion 155a and the motor gear 164, the load torque of a plurality of gears meshing with the external tooth portion 155b is applied to the meshing portion of the internal tooth portion 155a. Load torque is large. Furthermore, in this embodiment, since the cylindrical portion 1 is tilted as shown by the dotted line in FIG. The stress load applied to the roots becomes large. Further, the radius of the internal teeth is shorter than that of the external teeth, and from the viewpoint of obtaining a high reduction ratio, the module of the internal toothed portion 155a is smaller than the module of the external toothed portion 155b. Therefore, the tooth strength of the internal toothed portion 155a is also weaker than that of the external toothed portion 155b. As a result, if the cylindrical portion 1 is tilted significantly, cracks will occur on the connecting portion side of the internal teeth of the internal tooth portion 155a, and the developing internal and external gear integral gear 155 will be damaged.

If the developing gear 155 with internal internal teeth and external teeth is damaged in this way, the developing roller cannot be driven normally, and there is a possibility that an abnormal image or abnormal noise may be generated. The developing internal gear/external gear integral gear 155 is disposed between the rear plate 144 fixed to the main body of the apparatus and the gear bracket 163. Therefore, in order to remove the damaged internal and external development gear 155 from the drive pin 163a and replace it with a new internal and external development gear 155, it is necessary to remove the rear plate 144 or the gear bracket 163 from the main body of the apparatus. However, it is not easy to remove these from the device body.

Therefore, in this embodiment, a deformation amount detection means is provided to detect the deformation of the developed internal and externally toothed integral gear 155. When the deformation detection means detects the deformation, the color developing motor 160 is stopped to prevent damage to the internal and external developing gear 155. Characteristic parts of this embodiment will be described below with reference to the drawings.

FIG. 12 is a schematic diagram of the area around the developing internal-toothed external-tooth integral gear 155 in this embodiment.
As shown in FIG. 12, a displacement detection sensor 91 serving as a deformation amount detection means is arranged facing the outer circumferential surface of the cylindrical portion 1. As shown in FIG. The displacement detection sensor 91 may be a distance sensor that measures the distance by measuring the time it takes for light irradiated from a light emitting element toward the object to be measured to be reflected and incident on a light receiving element. It is possible to measure the displacement in the radial direction. By measuring the displacement in a non-contact manner in this way, it is possible to prevent an increase in the load torque of the development internal gear and external gear integral gear 155.

As shown by the dotted line in the figure, when an abnormal load is applied to the integrated gear 155 with internal and external teeth, it deforms so as to tilt with respect to the axial direction using the connection point between the shaft support part 3 and the connection part 2 as a fulcrum. do. Due to this deformation, the opening side end (other axial end: motor side end) of the cylindrical portion 1 is displaced most in the radial direction. In other words, the opening side end of the cylindrical portion 1 is the part that is displaced most in the radial direction when the internal toothed portion 155a is in partial contact with the motor gear 164.

Therefore, in this embodiment, the displacement detection sensor 91 is arranged near the opening side end of the outer circumferential surface of the cylindrical portion 1 so as to face each other. By arranging the displacement detection sensor 91 oppositely near the open end of the outer circumferential surface of the cylindrical portion 1, the displacement detection sensor 91 can detect that the internal toothed portion 155a is in a state of uneven contact with the motor gear 164. It can be detected with high accuracy.

In this embodiment, the external teeth 155b formed on the outer circumferential surface of the cylindrical portion 1 are provided only at one end in the axial direction (the end on the process unit side) of the cylindrical portion 1, and the displacement detection sensor 91 is It is configured to detect displacement of the surface of the cylindrical portion 1 on which teeth are not formed. This is because, in this embodiment, as described above, the displacement detection sensor 91 measures the amount of displacement based on the time it takes for the irradiated light to reflect from the outer peripheral surface of the cylindrical part 1 and return. . Therefore, if external teeth are formed on the outer circumferential surface of the cylindrical portion 1 at a location where the displacement detection sensor 91 faces, the light returning to the displacement detection sensor 91 will be reduced, and there is a risk that the amount of displacement cannot be measured normally. Because there is.

A control section 90 is connected to the displacement detection sensor 91. Further, the color developing motor 160 and the display section 92 are connected to the control section 90, and the control section 90 controls the color developing motor 160 and the display section 92. Further, the control section 90 is connected via an external communication section 93 to a personal computer 94 in which a printer driver is installed. The control unit 90 stops driving the color developing motor 160 based on the detection result of the displacement detection sensor 91. Furthermore, when the control unit 90 stops driving the color developing motor 160 based on the detection result of the displacement detection sensor 91, the control unit 90 displays on the display unit 92 or the personal computer 94 that an abnormal load has occurred. .

FIG. 13 is a process flowchart for preventing damage to the development gear 155 with internal and external teeth.
As shown in FIG. 13, when the color developing motor 160 starts to be driven, the control unit 90 starts measuring the displacement of the opening side end of the cylindrical part using the displacement detection sensor 91 (S1), and It is monitored whether the displacement amount exceeds a threshold value (S2). When the amount of displacement exceeds the threshold value (Yes in S2), the cylindrical portion 1 of the developing internal and external gear 155 is greatly deformed due to the abnormal load, and the internal toothed portion 155a is in uneven contact with the motor gear 164. It becomes. Therefore, at this time, the driving of the color developing motor 160 is stopped (S3). As a result, it is possible to prevent uneven contact from occurring and to continue driving, and to prevent cracks from occurring in the internal teeth of the internal tooth portion 155a and damage to the developing internal tooth external tooth integrated gear 155. I can do it. Furthermore, it is also possible to detect that an abnormality has occurred in at least one of the color developing rollers 81Y, 81M, and 81C.

Further, a warning display as shown in FIG. 14 is displayed on the display unit 92 of the printer or the screen of the personal computer 94 that issued the image formation command (S4). In the example shown in FIG. 14, a display is displayed instructing the user to contact a service person, but the control unit 90 may also contact a service center via the external communication unit 93, for example. .

In the above description, since the color developing motor 160 rotationally drives the three developing rollers 81Y, 81M, and 81C for Y, M, and C colors, it is not possible to determine which developing roller is experiencing the abnormal load. If an abnormal developing roller that is experiencing an abnormal load can be identified, a display may be displayed to instruct the user to replace the process unit that includes the identified developing roller.

In addition, when the drive is stopped to prevent damage to the developing gear 155 with internal internal teeth and external teeth, the abnormal load is detected on which of the three developing rollers 81Y, 81M, and 81C for Y, M, and C colors. A function for diagnosing may be provided. For example, if a clutch is provided in the unit-side developing gear train 180Y, 180M, 180C for each color, and only one of the three clutches is connected to drive one of the three developing rollers 81Y, 81M, 81C, then The displacement detection sensor 91 detects the deformation of the developing gear 155 with internal and external teeth. When the displacement of the opening side end of the cylindrical portion exceeds a specified value, it is determined that an abnormal load has occurred on the developing roller that transmitted the drive. On the other hand, if the displacement is less than the specified value, the clutch to be connected is changed and another developing roller is processed. By performing this operation for the three developing rollers 81Y, 81M, and 81C, it is possible to identify which developing roller is experiencing an abnormal load. Then, a message may be displayed on the display unit 92 or the personal computer 94 in which the printer driver is installed, instructing the process unit having the identified developing roller in the abnormal state to be replaced.

FIG. 15 is a schematic configuration diagram showing a modification of this embodiment.
In the modification shown in FIG. 15, the amount of deformation of the connecting portion 2 is detected by a displacement detection sensor 91.
As shown in FIG. 15, depending on the layout of the device, an external tooth portion 155b formed on the outer peripheral surface of the cylindrical portion 1 may be provided on the opening side of the cylindrical portion 1. In such a case, as shown in FIG. 15, the displacement detection sensor 91 may be arranged to face the connecting portion 2 to measure the displacement of the connecting portion 2.

The displacement detection sensor 91 is disposed facing the outside (on the side opposite to the drive pin 163a side) of the radial center of the connecting portion 2 (see the dashed line C in the figure), and is located outside the radial center of the connecting portion 2. Detects the displacement of As described above, when an abnormal load is applied to the integral developing gear 155 with internal and external teeth, the integral developing internal and externally toothed gear 155 deforms using the connection point between the shaft support part 3 and the connecting part 2 as a fulcrum. Therefore, in the connecting portion 2, the displacement is larger on the outside (on the drive pin 163a side) than on the inside (on the drive pin 163a side) of the radial center of the connecting portion 2 (see dashed line C in the figure). Therefore, by detecting the displacement outside the radial center of the connecting portion 2 with the displacement detection sensor 91, the displacement detection sensor 91 can detect that the internal tooth portion 155a is in a state of partial contact with the motor gear 164. This allows for highly accurate detection.

Although an example in which the present invention is applied to the collar drive device 150 has been described above, the present invention can be applied to any drive device whose gear train includes an internal gear. Further, in the above description, the outer circumferential surface of the cylindrical portion 1 has the external tooth portion 155b, but the present invention can also be applied to an internal gear without the external tooth portion 155b. The internal gear is fixed to the shaft of the driven body, and the driving force transmitted to the internal teeth rotates the internal gear together with the driven body. In this way, even with an internal gear without the external tooth portion 155b, depending on the rigidity of the internal gear and the torque of the motor, the radial load torque applied between the motor gear and the internal tooth when an abnormal load occurs. As a result, the cylindrical portion 1 is tilted, and the inner teeth may come into partial contact with the motor gear, causing cracks in the inner teeth. Therefore, even if the internal gear does not have external teeth on the outer peripheral surface of the cylindrical part, damage to the internal gear can be prevented by detecting the amount of deformation of the internal gear and stopping the drive. .

What has been described above is just an example, and each of the following aspects has its own unique effects.
(Aspect 1)
A developing device that includes a driving source such as a color developing motor 160 and a cylindrical portion 1 having an internal tooth portion 155a on the inner peripheral surface, and transmits the driving force of the driving source to driven objects such as developing rollers 81Y, 81M, and 81C. In a drive device such as a collar drive device 150 that includes a drive transmission member such as an internal gear and an external tooth integral gear 155, a deformation amount detection means such as a displacement detection sensor 91 that detects deformation of the drive transmission member, and a deformation amount detection means. The control unit 90 is provided with control means such as a control unit 90 that controls the drive source based on the detection result.
When a driven member such as the developing roller 81 becomes difficult to rotate due to some reason and an abnormal load occurs, the load torque applied to the tooth surface of the internal tooth at the meshing part of the internal tooth portion 155a with a gear such as the motor gear 164 increases. do. Since the tooth surfaces of the internal teeth are inclined surfaces, the load torque applied to the tooth surfaces acts in the circumferential direction and the radial direction, and as the load torque increases, the load torque f1 acting in the radial direction also increases. The load torque f1 acting in the radial direction may deform the drive transmission member such as the developing internal gear with external teeth 155 so that the cylindrical portion 1 is inclined with respect to the axial direction. In particular, as described in Patent Document 1, in the case where the external tooth portion 155b is provided on the outer circumferential surface of the cylindrical portion 1, in the meshing portion of the external tooth portion 155b, the outer tooth of the external tooth portion 155b also has a radial direction. Since the load torque (see f2 and f3 in FIG. 11) is applied, the cylindrical portion 1 is likely to be deformed so as to be inclined with respect to the axial direction. When the cylindrical portion 1 is tilted with respect to the axial direction, uneven contact occurs in which tooth contact is concentrated in a part of the tooth width direction at the meshing part of the internal tooth part 155a, and stress is concentrated in a part of the tooth width direction. do. As a result, cracks may occur at the roots of the internal teeth of the internal tooth portion 155a, and the drive transmission member may be damaged.
On the other hand, in aspect 1, when the deformation amount detection means such as the displacement detection sensor 91 detects deformation of the drive transmission member to the extent that there is a risk of tooth cracking occurring in the internal teeth due to uneven contact, the control unit 90 etc. By means of this means, it is possible to stop driving the drive source such as the color developing motor 160. This makes it possible to prevent the drive transmission member from being damaged due to tooth cracking in the internal teeth of the drive transmission member.

(Aspect 2)
In aspect 1, the control means such as the control unit 90, when the deformation amount detection means such as the displacement detection sensor 91 detects that the amount of deformation of the drive transmission member such as the developing internal tooth external tooth integral gear 155 exceeds a threshold value, , the drive source such as the color developing motor 160 is stopped.
According to this, as described in the embodiment, it is possible to prevent the internal teeth from continuing to drive in a state of uneven contact, and it is possible to prevent cracks from occurring in the internal teeth. This makes it possible to prevent damage to the drive transmission member, such as the developing gear 155 with internal internal teeth and external teeth.

(Aspect 3)
In embodiment 1 or 2, the outer peripheral surface of the cylindrical portion 1 of the drive transmission member, such as the integrated developing internal gear and external gear 155, has an external toothed portion 155b.
According to this, as explained in the embodiment, since load torque in the radial direction is also applied to the meshing portion of the external tooth portion of the cylindrical portion 1 with the external teeth, when an abnormal load occurs, the cylindrical portion 1 tends to tilt in the axial direction, resulting in uneven contact between the internal teeth and easy damage. Therefore, it is preferable to provide the configuration of aspect 1 or 2 to prevent damage to the drive transmission member.

(Aspect 4)
In any one of the first to third aspects, the deformation amount detection means such as the displacement detection sensor 91 is a non-contact sensor.
According to this, it is possible to prevent an increase in the load torque of the drive transmission member such as the developing gear 155 with internal internal teeth and external teeth.

(Aspect 5)
In any of the first to fourth embodiments, the deformation amount detection means such as the displacement detection sensor 91 detects the displacement in the radial direction of the cylindrical portion 1 of the drive transmission member such as the development internal gear and external gear 155.
According to this, as described in the embodiment, uneven contact of the internal teeth occurs in accordance with the inclination in the axial direction of the cylindrical portion 1. Therefore, it is possible to directly detect the amount of inclination of the cylindrical portion 1 with respect to the axial direction, which is a cause of uneven contact, which is a factor in detecting the radial displacement of the cylindrical portion 1, using a deformation amount detection means such as the displacement detection sensor 91. Thereby, it is possible to accurately detect that the internal teeth are in a state of uneven contact, and it is possible to satisfactorily prevent damage to the drive transmission member.

(Aspect 6)
In the fifth aspect, the deformation detection means such as the displacement detection sensor 91 detects the radial displacement of the surface of the cylindrical portion 1 on which teeth are not formed.
According to this, as described in the embodiment, the displacement in the radial direction of the cylindrical portion 1 can be detected with high accuracy.

(Aspect 7)
In any of aspects 4 to 6, the drive transmission member such as the development internal gear and external gear integral gear 155 includes a shaft support portion 3 having a shaft insertion hole 155c into which a shaft such as a drive pin 163a is inserted; A connecting portion 2 that connects one axial end of the cylindrical portion 1 is provided, and a deformation detection means such as a displacement detection sensor 91 detects a radial displacement of the other axial end of the cylindrical portion 1 .
According to this, as described in the embodiment, when the cylindrical portion 1 of the drive transmission member, such as the developing internal gear 155, is tilted with respect to the axial direction due to an abnormal load, it is most displaced in the radial direction. By detecting the other axial end of the cylindrical portion 1 with a deformation amount detection means such as the displacement detection sensor 91, the amount of inclination of the cylindrical portion 1 with respect to the axial direction can be detected with high sensitivity. Thereby, it is possible to accurately detect that the internal teeth are in a state of uneven contact, and it is possible to satisfactorily prevent damage to the drive transmission member.

(Aspect 8)
In any one of aspects 1 to 4, the drive transmission member such as the integrated gear 155 with internal and external development teeth includes a shaft support portion 3 having a shaft insertion hole 155c into which a shaft such as a drive pin 163a is inserted; A connecting portion 2 that connects one axial end of the cylindrical portion 1 is provided, and a deformation detection means such as a displacement detection sensor 91 detects displacement of the connecting portion 2 in the axial direction.
According to this, as described in the embodiment, when an abnormal load is applied to a drive transmission member such as the integral gear 155 with internal and external development teeth, the connection point between the connection part 2 and the shaft support part 3 is used as a fulcrum. The connecting portion 2 is tilted in the radial direction, and the cylindrical portion 1 is tilted in the axial direction. When the cylindrical portion 1 is tilted with respect to the axial direction, uneven contact occurs on the internal teeth. Therefore, by detecting the displacement of the connecting portion 2 in the axial direction and detecting the amount of inclination of the connecting portion 2 with respect to the radial direction, it is possible to estimate the inclination of the cylindrical portion with respect to the axial direction. Thereby, it is possible to detect that the internal teeth are in a state of uneven contact, and it is possible to prevent damage to the drive transmission member.

(Aspect 9)
In the eighth aspect, the deformation detection means such as the displacement detection sensor 91 detects the displacement in the axial direction outside the radial center of the connecting portion 2 .
According to this, as described in the embodiment, when the connecting portion 2 of the drive transmission member, such as the integral developing gear 155 with internal and external teeth, is inclined with respect to the radial direction due to an abnormal load, the part that is most displaced is This is the radially outer end. Therefore, by detecting the displacement in the axial direction outside the radial center of the connecting portion 2 using a deformation detection means such as the displacement detection sensor 91, the amount of inclination of the connecting portion 2 in the radial direction can be detected with high sensitivity. .

(Aspect 10)
In any one of aspects 1 to 9, when the deformation amount detection means such as the displacement detection sensor 91 detects that the amount of deformation of the drive transmission member such as the development internal tooth external tooth integrated gear 155 exceeds a threshold value, a warning is displayed. conduct.
According to this, it is possible to warn the user that an abnormality has occurred in the device, such as an abnormal load, and prompt the user to take a predetermined countermeasure.

(Aspect 11)
In an image forming apparatus such as a printer that includes a driven member such as a developing roller and a driving device such as the color drive device 150 that drives the driven member, the driving device according to any one of Aspects 1 to 10 is used as the driving device. there was.
According to this, it is possible to prevent damage to the drive transmission member such as the developing gear 155 with internal internal teeth and external teeth.

1 : Cylindrical part 2 : Connecting part 3 : Shaft support part 15 : Development drive gear train 23 : Development unit 24 : Photoreceptor 26 : Process unit 81 : Development roller 90 : Control part 91 : Displacement detection sensor 92 : Display part 93 : External communication section 94 : Personal computer 100 : Printer 141 : Rear side plate 144 : Rear side plate 150 : Collar drive device 151 : Idler gear pulley 151a : Idler gear part 151b : Pulley part 152 : Drive output gear 152a : Followed gear part 152b : Pulley part 152c: Drive-side coupling portion 153: First timing belt 154: Second timing belt 155: Developing internal tooth external tooth integrated gear 155a: Internal tooth portion 155b: External tooth portion 155c: Shaft insertion hole 156: First tightener 157: Second tightener 160: Color developing motor 160a: Motor shaft 163a: Drive pin 164: Motor gear 180: Unit side developing gear train 181: Driven side coupling 182: Developing input gear 183: Developing idler gear 184: Developing output gear

Patent No. 6399322

Claims (11)

A driving source,
A drive device including a cylindrical part having an internal toothed part on an inner circumferential surface, and a drive transmission member that transmits the driving force of the drive source to a driven object,
deformation amount detection means for detecting deformation of the drive transmission member;
A drive device comprising: a control means for controlling the drive source based on a detection result of the deformation amount detection means. The drive device according to claim 1,
The drive device is characterized in that the control means stops driving the drive source when the deformation amount detection means detects that the amount of deformation of the drive transmission member exceeds a threshold value. The drive device according to claim 1 or 2,
A drive device characterized in that the cylindrical portion of the drive transmission member has an external toothed portion on an outer circumferential surface thereof. The drive device according to any one of claims 1 to 3,
A drive device characterized in that the deformation amount detection means is a non-contact sensor. The drive device according to any one of claims 1 to 4,
The drive device, wherein the deformation amount detection means detects a radial displacement of the cylindrical portion of the drive transmission member. The drive device according to claim 5,
The drive device is characterized in that the deformation amount detection means detects the deformation amount of a surface of the cylindrical portion on which teeth are not formed. The drive device according to claim 5 or 6,
The drive transmission member includes a shaft support portion having a shaft insertion hole into which the shaft is inserted, and a connection portion that connects the shaft support portion and one axial end of the cylindrical portion,
The drive device is characterized in that the deformation amount detection means detects a radial displacement of the other axial end of the cylindrical portion. The drive device according to any one of claims 1 to 4,
The drive transmission member includes a shaft support portion having a shaft insertion hole into which the shaft is inserted, and a connection portion that connects the shaft support portion and one axial end of the cylindrical portion,
The drive device, wherein the deformation amount detection means detects displacement of the connecting portion in the axial direction. The drive device according to claim 8,
The drive device is characterized in that the deformation amount detection means detects an axial displacement outside the radial center of the connecting portion. The drive device according to any one of claims 1 to 9,
A drive device characterized in that, when the deformation amount detection means detects that the deformation amount of the drive transmission member exceeds a threshold value, a warning is displayed. a driven body;
An image forming apparatus including a drive device for driving the driven body,
An image forming apparatus characterized in that the drive device according to any one of claims 1 to 10 is used as the drive device.

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