JP6170764B2 - Belt offset adjustment mechanism - Google Patents

Description

  The present invention relates to a belt shift adjustment mechanism, and more particularly to a belt shift adjustment mechanism applied to an image forming apparatus such as an electrophotographic apparatus.

  Conventionally, there is Patent Document 1 relating to a belt shift adjustment mechanism. In Patent Document 1, a non-rotatable sun gear 38 provided on the roller shaft 21 of the meandering control roller 18, a ring gear 39 provided integrally with the drive gear 30, and a meandering detector 29 are rotatably supported. A rotation amplification mechanism 37 composed of a planetary gear mechanism having a sun gear 38 and a pinion gear 41 meshing with the sun gear 38 and the ring gear 39 is provided, and the drive gear 30 is rotated by amplifying the amount of rotation of the meandering detection unit 29.

  With this configuration, when the belt edge of the flat belt B that is to meander on the meandering detection unit 29 rides on and comes into contact with the meandering detection unit 29, rotational torque is generated in the meandering detection unit 29, and the rotation amount (rotation angle) is determined by the roller movable end drive mechanism. In 35, the amount of displacement of the movable end 18a of the meandering control roller 18 is converted to meandering control for correcting the deviation of the flat belt B.

JP 2002-181144 A

  The configuration described in Patent Document 1 operates using a frictional force generated at the end of the flat belt B and the outward flange portion 29a of the meandering detection portion 29 as a driving force. Further, in this configuration, it is necessary to further improve the frictional force in order to reliably stabilize the operation, but there is a limit.

In order to solve the above problems, the present invention provides two or more rollers, a belt stretched around these rollers, and one end of each of the rollers, and when the belt is rotated by the rollers, Adjusting means for adjusting the generated deviation of the belt, and the adjusting means is disposed on one end side of the roller, and has a smooth portion having the same diameter as the roller, and outward from the end of the flat end portion. And a skew roller having a speed reduction mechanism therein, and the speed reduction mechanism includes an internal tooth cycloid gear fitted inside the skew roller, and a mesh with the internal tooth cycloid gear. and external teeth cycloid gears consists an output gear for transmitting the rotation of the external tooth cycloid gear, by adjusting the rotation of the skew rollers, to, characterized in that to adjust the offset of the belt .

According to a second aspect of the present invention, the biasing means for assisting the rotation of the skew roller by biasing the output gear decelerated by the speed reduction mechanism on the opposite side of the skew roller having the speed reduction mechanism fitted thereto. Is provided.

  As described above, by providing the adjusting means having the speed reduction mechanism in one roller, the frictional force for operating the adjusting means is improved, and the operation of the mechanism for adjusting the adjustment of the deviation of the belt can be stabilized. . In particular, the adjusting means is a skew roller, and the speed reduction mechanism is an internal tooth cycloid gear fitted inside the skew roller, an external tooth cycloid gear meshed with the internal tooth cycloid gear, and the external tooth cycloid gear. By comprising the output gear that transmits the rotation, the stabilization of the mechanism operation can be realized.

  Furthermore, the rotation of the skew roller can be assisted by providing an urging means for urging the output gear decelerated by the decelerating mechanism on the opposite side of the skew roller having the decelerating mechanism fitted therein. Further, the biasing means can be realized by assisting the rotation of the skew roller by using a mainspring spring.

Schematic of an apparatus to which the belt offset adjusting mechanism of the present invention is applied FIG. 3 is a schematic view of a belt deviation adjusting mechanism of the present invention. The figure which looked at the deceleration mechanism from the arrow A of FIG. The figure which looked at the output gear from the arrow A of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic view of an apparatus to which the belt deviation adjusting mechanism of the present invention is applied. As shown in FIG. 1, this apparatus is an image forming apparatus including an image forming unit 10, a transfer unit 20, and a fixing unit 30. With this configuration, the sheet is fed out from a sheet feeding unit (not shown), the toner image formed by the image forming unit 10 is transferred to the sheet by the transfer unit 20, and the sheet is fixed by the fixing unit 30. .

The image forming unit 10 includes an image carrier 11, a charge eliminating unit 12, a charging unit 13, an exposure unit 14, and a developing unit 15, and each unit is disposed at an appropriate position around the image carrier 11. For example, the image carrier 11 rotates in a direction indicated by an arrow, that is, counterclockwise, and has a configuration in which an electrophotosensitive member is provided on the surface of a drum-like substrate such as aluminum. As the photoconductor, a known photoconductor such as an OPC (organic photoconductor) photoconductor or an amorphous silicon photoconductor can be used.

  The neutralizing means 12 is for erasing charges remaining on the surface of the image carrier 11 to neutralize the surface of the image carrier 11 and is specifically an eraser lamp. The charging unit 13 uniformly charges the surface of the image carrier 11 neutralized by the charge eliminating unit 12 to a characteristic polarity, and is specifically a corona charger.

  The exposure device 14 is for making optical information incident on the surface of the charged image carrier 11 (image exposure) to form an electrostatic latent image on the surface of the image carrier 11.

The developing means 15 develops the toner image on the electrostatic latent image formed on the image carrier 11 by the exposure means 14 described later. Specifically, the developing means 15 includes a toner cartridge filled with toner, and a toner cartridge. A developing container containing the supplied toner and a developing roller are provided.

The transfer unit 20 includes a transfer roller 21 and a belt 200 incorporated in the belt driving device of the present invention. Belt 200 is intended to convey to the fixing unit 30 from the transfer roller 21 a sheet, it is stretched in a more under tension in a plurality of rows la.

Specifically, as shown in FIG. 1, the top roller 22, the dependent roller 23, it is stretched by two or more rollers of the control roller 2 4. One roller of the present invention refers to a control roller.

The top roller 22 is connected to a drive source (not shown) that rotates the belt 200. Further, a transfer roller 21 is disposed at a position facing the top roller 22 . One end of the control roller 2 4 is fixed at a predetermined position, the other end of the control roller 2 4, the adjusting means 300 is provided. Adjusting means 300, the top roller 22, when more belt 200 is rotated in the dependent roller 23 and the control roller 2 4, as a fulcrum at one end of the control roller 2 4, and to tilt the control roller 2 4 at a predetermined angle, The offset of the belt 200 is adjusted. This inclination is a slight one of about 1 to 5 °.

As shown in FIG. 2, the adjustment means 300, a smoothing unit 510 having the same diameter as the control roller 2 4 consists skew roller 500 having a tapered portion 520 whose diameter is enlarged in accordance with outwardly from the end of the smooth portion 510 parts. The skew roller 500 has a U-shaped cross section, and on the control roller 24 side , a first accommodating portion 530 that accommodates a part of the urging means 600 described later and a support shaft 550 of the control roller 24 are provided. A second shaft accommodating portion 540 that accommodates the bearing 551 to be received is provided.

Furthermore, a third accommodating portion 560 that accommodates the speed reduction mechanism 400 is provided on the opposite side where the control roller 24 is disposed. The third housing portion 560 has a protruding portion 570 extending from the second shaft housing portion 540, and a bearing that receives the speed reduction mechanism 400 is disposed on the outer peripheral surface thereof.

  The projecting portion 570 is provided with a mounting portion 580 for placing an external-tooth cycloid gear 410 described later at a predetermined position. As shown in FIG. 3, the attachment portion 580 has an oval shape so as to have a function of preventing rotation of the external cycloid gear 410 of the speed reduction mechanism 400 described later.

  The speed reduction mechanism 400 reduces the rotation of the skew roller 500 by using a force acting by friction between the belt 200 and the tapered portion 520 when the belt 200 approaches the skew roller 500. The speed reduction mechanism 400 includes an internal tooth cycloid gear 420, an external tooth cycloid gear 410, and an output gear 430.

The internal tooth cycloid gear 420 has a housing portion 421 for housing the external tooth cycloid gear 410 inside, and an insertion hole to which a bearing through which the support shaft 550 passes is attached. 500 is inserted into the third accommodating portion 560. Further, the insertion hole protrudes outward, and teeth that screw into threads formed on the peripheral surface of the external tooth cycloid gear 410 are provided on the inner peripheral edge of the internal tooth cycloid gear 420.

  The external-tooth cycloid gear 410 is for decelerating the rotation of the output gear 430 when the belt 200 enters the region of the tapered portion 520 of the skew roller 500 and the skew roller 500 rotates. The external gear cycloid gear 410 includes two parts, a first external tooth cycloid gear 410a and a second external tooth cycloid gear 410b.

  The first external gear cycloid gear 410a and the second external tooth cycloid gear 410b are formed with a screw thread that is screwed to the teeth of the internal cycloid gear 420 on the outer circumference circle, a mounting hole for attaching a plate in the center, and the mounting hole 411 A pin hole 412 is provided between the threads.

  In the following description, a plate attached to the first external tooth cycloid gear 410a is referred to as a first plate 411a, and a plate attached to the second external tooth cycloid gear 410b is referred to as a second plate 411b.

Furthermore, as shown in FIGS. 2 and 3, the first plate 411a and the second plate 411b, respectively, have substantially the same thickness as the external tooth cycloid gear 410 that is mounted, the shaft hole (413a through a support shaft 550 , 413b ).

The shaft through holes ( 413 a, 413 b ) have a shape that fits into the mounting portion 580 (an oval shape), and are further provided at positions slightly shifted from the centers of the first plate 411 a and the second plate 411 b. . Thereby, in the internal-tooth cycloid gear 420, the 1st external-tooth cycloid gear 410a and the 2nd external-tooth cycloid gear 410b are arrange | positioned in the eccentric position.

In this embodiment, the shaft through holes ( 413 a, 413 b ) have an oval shape and the cross-sectional shape of the mounting portion 580 is formed in an oval shape and protruded. However, the present invention is limited to this. For example, the non-circular shape other than the oval shape is adopted, for example, the shaft through hole is formed in an elliptical hole, and the cross-sectional shape of the mounting portion 580 is correspondingly formed in an elliptical shape. Also good.

  The output gear 430 transmits rotation decelerated by the speed reduction mechanism 400 when the belt 200 enters the region of the taper portion 520 of the skew roller 500. The output gear 430 has a diameter that covers the opening of the external tooth cycloid gear 410, and the side that covers the opening of the external tooth cycloid gear 410 is provided with pins that are inserted into the respective pin holes provided in the external tooth cycloid gear 410. Yes.

In addition, a pinion gear that meshes with a rack gear provided in a housing (not shown) is provided on the opposite side where the pins are provided. Rack gear, when the adjustment means 300 is activated, the control roller 2 4 as a fulcrum at one end, are arranged so as to be inclined at a predetermined angle.

  Furthermore, as shown in FIGS. 2 and 3, the pin hole has a diameter that fits with play when the pin is inserted. Further, the pins and the pin holes are equally arranged symmetrically in order to obtain transmission of rotation of the external cycloid gear 410 uniformly.

  When the rotation decelerated by the speed reduction mechanism 400 is transmitted to the output gear 430, the urging unit 600 cannot rotate the skew roller 500 with the rotational force, and therefore the friction between the skew roller 500 and the belt 200 is generated. The skew roller 500 is urged so as to be generated, and the skew roller 500 is rotated by the friction, and is provided in the first housing portion 530.

  Although not shown in detail, the urging means 600 includes, for example, a mainspring spring including a spring material, a winding core (not shown), and a case. The spring material is wound in a spiral shape, one end is provided with a locking portion (not shown) that is fixed to a slit provided in the core, and the other end is provided in a mounting hole (not shown) provided in the case. A mounting portion (not shown) to be attached is provided. The winding core (not shown) is fixed to the case, and the spring material and the winding core (not shown) are accommodated in the case.

  Under the above configuration, the operation of the adjusting means 300 and the adjustment of the deviation of the belt 200 will be described. First, when the belt 200 is not offset, the area between the back surface of the belt 200 and the surface portion of the skew roller 500 that contacts the back surface of the belt 200 is small. Does not rotate. As a result, the adjusting means 300 does not operate.

  Next, a case where a deviation occurs in the belt 200 will be described. When the belt 200 gradually moves (is offset) in the arrow B direction (tapered portion 520 side) in FIG. 2, the back surface of the belt 200 and the surface portion of the skew roller 500 that contacts the back surface of the belt 200. The area will increase. As a result, friction occurs between the back surface of the belt 200 and the surface of the skew roller 500, and the skew roller 500 starts to rotate due to this friction.

  As the skew roller 500 rotates, the first external tooth cycloid gear 410a and the second external tooth cycloid gear 410b rotate, and the rotation is decelerated and transmitted to the output gear 430. The pinion gear rotates in the predetermined direction by the amount of deceleration, and the output gear 430 is displaced in the linear direction in the arrow direction C by the rack gear.

This displacement, as a fulcrum at one end of the control roller 2 4 adjustment means 300 is not provided, inclined to a predetermined angle. At this time, the urging force of the urging means 600 acts on the side opposite to the moving direction of the belt 200, and the torque generated in the skew roller 500 and the frictional force generated between the belt 200 and the skew roller 500 are antagonized. The skew roller 500 is rotated in the moving direction of the belt 200.

Along with this, the first external tooth cycloid gear 410a and the second external tooth cycloid gear 410b roll (cycloidal motion) around the axis of the support shaft 550 via the internal tooth cycloid gear 420. In response to this rolling (cycloid motion), rotates the output gear 430 via a pin, is also rotated along a rack gear pinion gear, as a fulcrum at one end of the control roller 2 4 gradually control roller 2 4 There tilts little by little.

  As a result, while the belt 200 returns to the original position, the area between the back surface of the belt 200 and the surface portion of the skew roller 500 that contacts the back surface of the belt 200 becomes small, that is, the position where the skew roller 500 does not rotate, The frictional force generated between the back surface of the belt 200 and the surface portion of the skew roller 500 in contact with the back surface of the belt 200 is adjusted so that the torque for rotating the belt 200 is balanced. Offset adjustment is performed.

  By providing the adjusting means provided with the speed reduction mechanism in one roller, the frictional force for operating the adjusting means is improved, and the operation of the mechanism for adjusting the deviation of the belt can be stabilized.

24 control roller 200 belt 300 adjusting means 400 decelerating means 500 skew roller 510 smoothing part 520 taper part 600 biasing means

Claims (2)

Two or more rollers, a belt stretched around these rollers, and an adjusting means that is provided on one end side of the one roller and adjusts a deviation of the belt generated when the belt is rotated by the roller. And
The adjusting means is disposed on one end side of the roller, and includes a smooth portion having the same diameter as the roller, a tapered portion having a diameter that increases outward from the end of the flat end portion, and a skew having a reduction mechanism inside. Made up of Laura,
The speed reduction mechanism includes an internal cycloid gear fitted inside the skew roller, an external cycloid gear meshed with the internal cycloid gear, and an output gear that transmits the rotation of the external cycloid gear. the adjusting the rotation of the skew rollers, belt drive, characterized in that to adjust the offset of the belt. On the opposite side of the skew roller on which the speed reduction mechanism is fitted, biasing means for biasing the output gear decelerated by the speed reduction mechanism to assist the rotation of the skew roller is provided. The belt driving device according to claim 1.