JP2019094982A - Drive unit and image formation apparatus - Google Patents

Abstract

To provide a drive unit and an image formation apparatus such that the drive unit can be made compact.SOLUTION: A drive unit 50 comprises: a drive source 51; a plurality of drive transmission members which transmit drive power of the drive source to a drive member 44; a drive source retaining member 52 which retains the drive source; an opposite member 56 which faces the drive source retaining member across at least one drive transmission member; and an intermediate member 66 which is arranged between the drive source retaining member 52 and the opposite member, and positioned at at least one member between the drive source retaining member and the opposite member, and has at least one of the plurality of drive transmission member. Fastening members 91a, 91b penetrate a positioning part which positions the intermediate member 66 and the one member and the drive source retaining member 52, intermediate member 66, and opposite member 56 are fastened together to a main body device.SELECTED DRAWING: Figure 19

Description

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

  Conventionally, a drive source, a plurality of drive transmission members for transmitting the drive force of the drive source to the drive member, a drive source holding member for holding the drive source, and a drive source holding member sandwiching at least one drive transmission member An opposing member disposed between the opposing member, a drive source holding member and the opposing member, positioned on at least one of the drive source holding member and the opposing member, and having one of a plurality of the drive transmission members A drive comprising a member is known.

  In Patent Document 1, a motor mounting plate serving as a drive source holding member for holding a motor serving as a drive source and a planetary gear mechanism including a plurality of drive transmission members such as a sun gear and an internal gear as the drive device And an output shaft end plate which is a facing member facing the motor mounting plate and a cylindrical housing which is an intermediate member positioned on the motor mounting plate and the output shaft end plate and having an internal gear. . The motor mounting plate has a cylindrical positioning protrusion having an outer diameter substantially the same as the inner diameter of the housing. The housing is positioned on the motor mounting plate by fitting the positioning projection of the motor mounting plate to the motor mounting plate side end of the housing. The output shaft end plate also has a cylindrical positioning protrusion whose outer diameter is substantially the same as the inner diameter of the housing, and this positioning protrusion is fitted to the output shaft end plate side end portion of the housing As a result, the housing is positioned on the output shaft end plate. The housing is held between the motor mounting plate and the output shaft end plate by fastening the motor mounting plate to a fastening portion to which the motor mounting plate provided outside the housing of the output shaft end plate is fastened. Fixed in the form of Thereby, the motor mounting plate, the output shaft end plate and the housing are fixed to each other. Further, a main body fastening portion for fastening to the main body device is provided outside the fastening portion to which the motor attachment plate of the output shaft end plate is fastened.

  However, in the drive device described in Patent Document 1, there is a possibility that the device may be enlarged.

  In order to solve the problems described above, the present invention comprises at least a drive source, a plurality of drive transmission members for transmitting the drive force of the drive source to the drive member, a drive source holding member for holding the drive source, One of the opposing members facing the drive source holding member with the drive transmission member interposed therebetween, and disposed between the drive source holding member and the opposing member, at least one of the drive source holding member and the opposing member And an intermediate member including one of the plurality of drive transmission members, wherein a fastening member passes through a positioning portion for positioning the intermediate member and the one member, and the drive source The holding member, the intermediate member, and the opposing member are fastened together to the main body device.

  According to the present invention, the drive device can be miniaturized.

FIG. 1 is a schematic configuration view showing a printer according to an embodiment. FIG. 2 is a perspective view of a fixing device. FIG. 3 is a main part configuration diagram of a pressure adjustment mechanism provided in the fixing device. FIG. 2 is a cross-sectional view orthogonal to the axial direction of the rear end of the fixing device. FIG. 2 is a cross-sectional view orthogonal to the sheet conveyance direction of the rear end portion of the fixing device. (A) is a figure which shows a mode that a pressure roller is in a pressurized state, (b) is a figure which shows a mode that a pressure roller is in a pressure-released state. The disassembled perspective view of the drive part of a pressurization adjustment mechanism. Sectional drawing of the drive part cut in parallel with the axial direction. The front view which looked at the drive part which removed the 2nd housing from the left side of FIG. The front view which removed the worm wheel, the 1st housing, the drive shaft, the 1st output gear, and the 2nd output gear from the state of FIG. 9 further. The disassembled perspective view of a load provision part. AA sectional drawing of FIG. BB sectional drawing of FIG. FIG. 7 is a diagram showing a state in which the pressure roller is shifted from the pressure released state (without pressure) to the pressure state. FIG. 8 is a view for explaining the movement of each gear of the drive section when the cam member rotates faster than the rotational speed at which the cam member receives a drive force from the drive motor by the biasing force of a spring and rotates. (A) is a figure which shows a mode before a drive connection member rotates faster than rotational drive speed, (b) is a mode that a drive connection member rotated faster than rotational drive speed by back torque. Figure showing. The figure which looked at the apparatus main body from the back side. The figure which looked at the back side board from the inside of an apparatus. The disassembled perspective view which looked at the bracket, the 1st housing, and the 2nd housing from the 2nd housing side. The figure which looked at the bracket, the 1st housing, the 2nd housing, and the back side surface of the apparatus main body from the apparatus back side. The perspective view which looked at the 1st housing from the 2nd housing side. EE sectional drawing of FIG. The figure which shows the state which fastened the drive part to the apparatus main body. AA sectional drawing of FIG. FIG. 24 is a cross-sectional view taken along the line B-B in FIG. CC sectional drawing of FIG. 23. DD sectional drawing of FIG. The modification of the bracket 52. FIG.

Hereinafter, as an image forming apparatus to which the present invention is applied, an electrophotographic printer (hereinafter, simply referred to as a printer) which forms an image by an electrophotographic method will be described.
FIG. 1 is a schematic configuration view showing a printer according to the embodiment.
The printer shown in FIG. 1 is a monochrome printer. A process cartridge 1 as a removable unit is detachably mounted on the apparatus main body 100. The process cartridge 1 visualizes a latent image on the photosensitive member 2 as a photosensitive member 2 as an image carrier that carries an image on the surface, a charging roller 3 as a charging unit that charges the surface of the photosensitive member 2, and The developing device 4 as a developing means, and a cleaning blade 5 as a cleaning means for cleaning the surface of the photosensitive member 2 are provided. Further, an LED head array 6 is disposed around the photosensitive member 2 as an exposure unit that exposes the surface.

  Further, in the process cartridge 1, a toner cartridge 7 as a developer container is detachably provided. The toner cartridge 7 has a developer accommodating portion 8 in the container main body 22 for accommodating toner which is a developer to be supplied to the developing device 4. Furthermore, the toner cartridge 7 of the present embodiment also integrally includes a developer recovery unit 9 that recovers the toner (waste toner) removed by the cleaning blade 5.

  The printer also includes a transfer unit 10 that transfers an image to a sheet material as a transfer material, a sheet feeding device 11 that supplies the sheet material, a fixing device 12 that fixes the image transferred to the sheet material, and the sheet material. And a delivery device 13 for delivering the image to the outside of the device.

  The transfer unit 10 includes a transfer roller 14 as a transfer member rotatably supported by the transfer frame 30. The transfer roller 14 is in contact with the photosensitive member 2 in a state where the process cartridge 1 is mounted on the apparatus main body 100, and a transfer nip is formed at the contact portion between the two. Further, the transfer roller 14 is connected to a power supply, and a predetermined DC voltage (DC) and / or an AC voltage (AC) is applied thereto.

  The sheet feeding device 11 includes a sheet feeding cassette 15 accommodating the sheet material P, and a sheet feeding roller 16 for feeding the sheet material P accommodated in the sheet feeding cassette 15. Further, on the downstream side of the sheet feeding direction with respect to the sheet feeding roller 16, a pair of registration rollers 17 are provided as timing rollers for feeding the sheet to the secondary transfer nip by measuring the feeding timing. Examples of the sheet material P include thick paper, postcard, envelope, plain paper, thin paper, coated paper (coated paper, art paper, etc.), tracing paper, OHP sheet, OHP film, and the like.

  The fixing device 12 includes a fixing roller 18 and a pressure roller 19. The fixing roller 18 is heated by an infrared heater 23 installed inside the fixing roller. The pressure roller 19 is pressed to the fixing roller 18 side and abuts against the fixing roller 18, and a fixing nip is formed at the abutting portion.

  The paper discharge device 13 includes a pair of paper discharge rollers 20. The sheet material discharged to the outside of the apparatus by the sheet discharge roller 20 is stacked on a sheet discharge tray 21 formed by denting the upper surface of the apparatus main body 100.

  Subsequently, the basic operation of the printer according to the present embodiment will be described with reference to FIG. When the image forming operation is started, the photosensitive member 2 of the process cartridge 1 is rotationally driven clockwise in FIG. 1, and the surface of the photosensitive member 2 is uniformly charged to a predetermined polarity by the charging roller 3. Light is irradiated from the LED head array 6 to the charged surface of the photosensitive member 2 based on image information input from an external device, and an electrostatic latent image is formed on the surface of the photosensitive member 2.

  The toner is supplied by the developing device 4 to the electrostatic latent image formed on the photosensitive member 2 in this manner, whereby the electrostatic latent image is visualized (visualized) as a toner image.

  Further, when the image forming operation is started, the transfer roller 14 is rotationally driven, and a predetermined direct current voltage (DC) and / or an alternating current voltage (AC) is applied to the transfer roller 14 to A transfer electric field is formed between the photosensitive member 2 and the photosensitive member 2.

  At the lower portion of the apparatus main body 100, the sheet feeding roller 16 starts rotational driving, and the sheet material P is delivered from the sheet feeding cassette 15. The transported sheet material P is temporarily stopped by the registration roller 17.

  Thereafter, rotational driving of the registration roller 17 is started at a predetermined timing, and the sheet material P is conveyed to the transfer nip in accordance with the timing at which the toner image on the photosensitive member reaches the transfer nip. Then, the toner image on the photosensitive member 2 is collectively transferred onto the sheet material P as a transfer body by the transfer electric field. Further, the residual toner on the photosensitive member that can not be transferred to the sheet material P is removed by the cleaning blade 5, and the removed toner is conveyed to the developer collection unit 9 and collected.

  Thereafter, the sheet material P to which the toner image has been transferred is conveyed to the fixing device 12, and the toner image on the sheet material P is fixed to the sheet material P in the fixing device 12. Then, the sheet material P is discharged to the outside of the apparatus by the pair of sheet discharge rollers 20, and is stocked on the sheet discharge tray 21.

  Further, an opening / closing cover 37 which can be opened and closed in the direction of the arrow in the drawing is provided on the side (right side in the drawing) of the sheet feeding side of the apparatus main body 100. By opening the open / close cover 37, the process cartridge 1 which is a detachable unit is taken out of the apparatus main body 100 from the opened opening.

FIG. 2 is a perspective view of the fixing device 12, and FIG. 3 is a main part configuration view of a pressure adjusting mechanism 40 provided in the fixing device 12. FIG. 4 is a cross-sectional view orthogonal to the axial direction of the rear end portion of the fixing device 12, and FIG. 5 is a cross-sectional view orthogonal to the conveyance direction of the sheet material P at the rear end portion of the fixing device 12.
The fixing device 12 has an infrared heater 23 disposed inside, and is a moving member that forms a fixing nip as a nip portion in pressure contact with the fixing roller 18 which is a heated member heated by the infrared heater 23 and the fixing roller 18. The pressure roller 19 and a pressure adjustment mechanism 40 that moves the pressure roller 19 relative to the fixing roller 18 and adjusts the pressure of the pressure roller 19 against the fixing roller 18 are provided.

  The pressure adjustment mechanism 40 biases the pressure roller 19 toward the fixing roller 18 via the lever member 41 and a pair of lever members 41 that adjustably support the pressure on the fixing roller 18 of the pressure roller 19. A pair of springs 43 serving as biasing means, a pair of cam members 44 for moving the pressure roller 19 away from the fixing roller 18 against the biasing force of the springs 43 via the lever member 41, and the cam members 44 It has a drive unit 50 which is a drive unit to drive.

  The fixing roller 18 is rotatably supported by a pair of side plates 47 on both axial sides thereof. Both axial sides of the pressure roller 19 are rotatably supported by the lever member 41 of the pressure adjustment mechanism 40. As shown in FIG. 3, each lever member 41 is provided with a support shaft 41 a at one end, and is rotatably supported by the side plate 47. A spring receiver 41b is provided at the other end of each lever member 41. One end of a spring 43 is attached to the spring receiver 41b, and the other end of the spring 43 is a side plate 47 as shown in FIG. It is attached to the spring receptacle 47a provided in. A cam receiver 42 is formed on the other end side of the lever member 41, and the cam member 44 is in contact with the cam receiver 42.

  The pair of cam members 44 are attached to the camshaft 44a by parallel pins 44c (see FIG. 5) so as to rotate integrally with the camshaft 44a. At the rear end (right end in FIG. 2) of the camshaft 44a, the cam gear 55 engaged with the second output gear 54 of the drive unit 50 is rotated by the parallel pin 55a so as to rotate integrally with the camshaft 44a. It is attached to the shaft 44a.

  Further, the cam gear 55 is formed with a filler 45 a of a rotation angle detection mechanism 45 for detecting the rotation angle of the cam member 44. Further, an optical sensor 45 b for detecting the filler 45 a of the rotation angle detection mechanism 45 is attached to the back side plate 47. The filler 45a has a semicircular shape, and the optical sensor 45b is a photo interrupter (transmission type optical sensor).

FIG. 6 (a) is a diagram showing the pressure roller 19 in a pressurized state, and FIG. 6 (b) is a diagram showing a pressure roller 19 in a pressure-released state. The left side in FIGS. 6 (a) and 6 (b) shows the state of the rotation angle detection mechanism 45 in the pressurized state and the state in the depressurized state.
As shown in FIG. 6, the lever member 41 is in contact with a bearing 46 that receives the shaft 19 a of the pressure roller 19. The bearing 46 is held by the side plate 47 so as to be capable of reciprocating in the direction of the arrow K in the drawing. The filler 45a of the rotation angle detection mechanism 45 is semicircular and has an opening 45c at one end side in the rotation direction.

  As shown in FIG. 6A, in the pressurized state, the filler 45a enters between the light emitting element and the light receiving element of the optical sensor 45b to block the optical path between them. Further, in the pressurized state, the lower dead center of the cam member 44 is in contact with the cam receiver 42.

  When the drive unit 50 is driven to shift from the pressurized state to the depressurized state, the cam member 44 and the filler 45a rotate counterclockwise in the drawing. Then, from the state shown in FIG. 6A, the cam member 44 pushes the cam receiver 42 downward in the figure against the biasing force of the spring 43. As a result, the lever member 41 rotates counterclockwise in the figure with the support shaft 41 a as a fulcrum, and the pressure roller 19 as the moving member is separated from the fixing roller 18 by the reaction force from the fixing roller 18. Then, the pressure on the fixing roller 18 of the pressure roller 19 decreases.

  Then, as shown in FIG. 6B, when the top dead center of the cam member 44 abuts on the cam receiver 42, the opening 45c is located between the light emitting element and the light receiving element of the optical sensor 45b. The light receiving element of the sensor 45 b detects the light of the light emitting element. Thereby, it can be detected that the pressure roller 19 has retracted to the pressure release position.

  In the present embodiment, when a paper jam occurs in the fixing device 12, the pressure adjusting mechanism 40 causes the pressure to be released. As a result, it is possible to facilitate the removal operation of the paper jammed in the fixing nip portion.

  Further, when the printer shifts from the standby state to the sleep mode or when the power is turned off, the pressure adjustment mechanism 40 reduces the pressure on the fixing roller 18 of the pressure roller 19 to generate creep in the nip portion. Can be prevented. In addition, even when a thick sheet such as an envelope is to be fed, the pressure adjustment mechanism 40 reduces the pressure on the fixing roller 18 of the pressure roller 19 to perform the fixing process without generating wrinkles. it can.

  When shifting from the depressurized state to the pressurized state, the drive motor 51 is driven in the opposite direction to the rotational direction when transitioning from the pressurized state to the depressurized state. Then, the cam member 44 is rotated about the center of the drawing, and the biasing force of the spring 43 causes the lever member 41 to rotate clockwise about the support shaft 41 a in the drawing, and the pressure roller 19 rotates the fixing roller 18. We will pressurize. The filler 45a enters between the light receiving element and the light emitting element of the optical sensor 45b, and when the light receiving element does not detect light and passes for a predetermined time, it is judged that the specified pressing force is reached. Stop driving.

FIG. 7 is an exploded perspective view of the drive unit 50 of the pressure adjustment mechanism 40, and FIG. 8 is a cross-sectional view of the drive unit 50 cut parallel to the axial direction. 9 is a front view of the drive unit 50 from which the second housing 56 is removed, as viewed from the left side of FIG. 8. FIG. 10 further shows the worm wheel 75 and the first housing 66 from the state of FIG. , The drive shaft 73, the first output gear 53 and the second output gear 54 are removed.
The drive unit 50 according to the present embodiment mainly includes the drive motor 51, the worm gear 60, the planetary gear mechanism 70, and the load applying unit 80, and the driving force of the worm gear 60, the load applying unit 80, and the planetary gear mechanism 70 is in this order. It is transmitted.

  As the drive motor 51, a brush motor that is less expensive and smaller than a brushless motor is used. The drive motor 51 is held by a bracket 52 which is a motor holding member. Specifically, the bracket 52 has a motor holding surface 155 parallel to the rotational axis direction of the planetary gear mechanism 70. The motor holding surface 155 has a notch 155 a through which the shaft of the drive motor 51 passes. Further, in the motor holding surface 155, two screw through holes 155b through which screws for screwing the drive motor 51 are provided are provided on both sides of the notch 155a. Two screw holes 51 a are formed on the surface of the drive motor 51 facing the motor holding surface 155 with the motor shaft interposed therebetween. The drive motor 51 is held by the bracket 52 by screwing a screw having a screw through hole of the motor holding surface 155 through the screw hole 51 a of the drive motor 51.

  The worm 61 of the worm gear 60 is attached to the motor shaft of the drive motor 51 so as to rotate integrally with the motor shaft. The worm wheel 75 meshes with the worm 61. The worm wheel 75 is supported by a drive shaft 73 rotatably supported by the bracket 52 via a bearing 154.

11 is an exploded perspective view of the load applying unit 80, FIG. 12 is a cross-sectional view taken along the line A-A of FIG. 8, and FIG. 13 is a cross-sectional view taken along the line B-B of FIG.
The load applying unit 80 mainly includes a drive side coupling 75a, a driven side coupling 71b, a drive shaft 73, and a torque limiter 72 as a load applying means. The drive side coupling 75 a is provided on the worm wheel 75. Drive-side engagement protrusions 175 are provided on the inner peripheral surface of the drive-side coupling 75a at intervals of 180 °. The worm wheel 75 is attached to the drive shaft 73 so as to rotate integrally. Specifically, the drive shaft 73 has a press-fit portion 73a having a substantially D-shaped cross section, and the worm wheel 75 is made of a material that can be elastically deformed to a certain extent such as a resin, and the cross section pressed into the press-fit portion 73a. It has a press-in hole 75c having a substantially D-cut shape. The worm wheel 75 is attached to the drive shaft 73 so as to rotate integrally with the drive shaft 73 by press-fitting the press-fit hole 75 c into the press-fit portion 73 a of the drive shaft 73 while elastically deforming (expanding) .

  One end of the drive shaft 73 is rotatably supported by the bracket 52 via a bearing 154. At the other end of the drive shaft 73, a support portion 73b rotatably supported by the second housing 56 is provided. The support portion 73 b has a shorter diameter than the press-fit portion 73 a.

  A torque limiter 72 as a load applying means and a drive connecting member 71 are attached to the drive shaft 73. Two notches 72 a extending in the axial direction are provided at an end of the torque limiter 72 on the worm wheel 75 side at an interval of 180 ° in the rotational direction. A parallel pin 74 is fitted in the drive shaft 73, and the parallel pin 74 is in the notch 72 a of the torque limiter 72.

  Further, at the drive connecting member side end of the torque limiter 72, two engaging projections 72b extending in the axial direction are provided at an interval of 180 ° in the rotational direction. The engagement projections 72 b enter into engagement holes 71 c provided on the opposite surface of the drive connection member 71 facing the torque limiter 72.

  The drive connection member 71 is rotatably supported by the drive shaft 73, and includes a driven coupling 71b and a gear portion 71a. The driven side coupling 71b has an outer diameter that enters into the drive side coupling, and on the outer peripheral surface, two driven side engaging projections 171 are provided at an interval of 180 ° in the rotational direction. There is.

  As shown in FIGS. 7 and 8, the planetary drive transmission member 62 is rotatably supported by a first support shaft 152 fixed to the bracket 52 by caulking. The planetary drive transmission member 62 is formed with a sun gear 62 b of the planetary gear mechanism 70.

  The planetary gear mechanism 70 has the above-mentioned sun gear 62b, three planet gears 65 meshing with the sun gear 62b, a carrier 64 rotatably supporting these planet gears 65, and an internal gear 66a meshing with these planet gears 65. doing. The planetary gear mechanism 70 also includes a carrier holder 63 for holding the planetary gear 65 on the carrier 64.

  The planet gears 65 are rotatably supported by planet supports 64 c provided on the carrier 64 at equal intervals in the rotational direction (see FIGS. 8 and 10). The carrier holder 63 is provided with a snap fit portion 63 a for attaching to the carrier 64. The carrier holder 63 is attached to the carrier 64 by passing the claw portion at the tip of the snap fit portion through the engagement hole 64 b of the carrier 64 while elastically deforming the snap fit portion 63 a. Thus, the planetary gear 65 is held by the carrier 64.

  The internal gear 66 a is provided to the first housing 66. The first housing 66 covers the worm gear 60, the planetary gear mechanism 70, and the load applying unit 80 by being combined with the bracket 52 and the second housing 56.

  As shown in FIGS. 7, 8 and 10, the carrier 64 has a cylindrical supported portion 64a to be supported by the first support shaft 152, and the supported portion 64a is supported by the first support The carrier 64 is rotatably supported by the first support shaft 152 by being fitted into the shaft 152. Further, on the outer peripheral surface of the supported portion 64a, three drive coupling convex portions 164 drivingly coupled to the first output gear 53 rotatably supported by the first support shaft 152 are spaced apart by 120 °. It is provided. On the other hand, on the opposite surface of the first output gear 53 to the carrier 64, there is provided a cylindrical portion into which the supported portion 64a is inserted, and on the inner peripheral surface of this cylindrical portion Three groove portions, in which the H.164 fits, are provided at intervals of 120 °. Thus, the driving force is transmitted from the carrier 64 to the first output gear 53.

  The second output gear 54 meshes with the first output gear 53, and the second output gear 54 is rotatably supported by a second support shaft 153 fixed to the bracket 52 by caulking. The second output gear 54 meshes with the cam gear 55 (see FIG. 2).

  When the drive motor 51 is rotationally driven, it is decelerated by the worm gear 60, and the drive side coupling 75a and the drive shaft 73 are rotationally driven. When the drive side engaging protrusion 175 of the drive side coupling 75 a is not in contact with the driven side engaging protrusion 171, the drive torque of the drive motor 51 is applied to the torque limiter 72 via the drive shaft 73. When the driving torque is applied to the torque limiter 72, the torque limiter 72 operates to interrupt the transmission of the driving force from the torque limiter 72 to the drive connecting member 71, and the drive connecting member 71 does not rotate.

  When the drive side engaging protrusion 175 of the drive side coupling 75a abuts on the driven side engaging protrusion 171, the driving force is transmitted from the drive side coupling 75a to the driven side coupling 71b, and the drive connecting member 71 is rotationally driven. Do. The driving force is transmitted from the gear portion 71a of the drive connection member 71 to the input gear 62a of the planetary drive transmission member 62, and the sun gear 62b of the planetary gear mechanism 70 is rotationally driven.

  When the sun gear 62b is rotationally driven, the planetary gear 65 meshing with the sun gear 62b revolves around the sun gear 62b while rotating. As the planetary gear 65 revolves around the sun gear 62 b, the carrier 64 rotates, and the first output gear 53 engaged with the carrier 64 rotates with the carrier 64. Then, the driving force is transmitted to the second output gear 54 meshing with the first output gear 53, and the cam member 44 is rotationally driven via the cam gear 55 (see FIG. 2).

  As described above, when the pressing force of the pressing roller 19 to the fixing roller 18 is reduced, it is necessary to push the lever member 41 against the biasing force of the spring 43 by the cam member 44, and the load of the cam member 44 Torque increases. Further, as a result of pushing the other end of the lever member 41 downward as shown in FIG. 3, the spring 43 is expanded, the biasing force of the spring 43 is increased, and the load torque of the cam member 44 is increased. Therefore, the load torque of the cam member 44 is increased as the pressing force of the pressing roller 19 to the fixing roller 18 is reduced.

  When the drive transmission mechanism for transmitting the drive force of the drive motor 51 of the drive unit 50 to the cam member 44 is constituted by a gear train for performing drive transmission by meshing of a plurality of external gears, a sufficient reduction ratio can not be obtained. Therefore, by using a motor having a large drive torque as the drive motor 51, the output torque output to the cam member 44 is made larger than the load torque. Thereby, the lever member 41 can be rotated against the biasing force of the spring 43. However, a motor with a large driving torque is large and expensive. As a result, there is a problem that the size of the apparatus is increased and the cost of the apparatus is increased.

  Therefore, the drive unit 50 of the present embodiment is configured to obtain a high reduction ratio by using the worm gear 60 and the planetary gear mechanism 70. As described above, since a high reduction ratio can be obtained, the output torque to the cam member 44 can be made larger than the load torque of the cam member 44 even if a motor having a low drive torque of the drive motor 51 is used. . As a result, even if an inexpensive small-sized brush motor with low driving torque is used as the driving motor 51, the cam member 44 can be rotationally driven well against the biasing force of the spring 43. The pressure on the fixing roller 18 can be adjusted.

  In addition, by using the worm gear 60 and the planetary gear mechanism 70, a large reduction ratio can be obtained without using a large diameter gear, and the size of the apparatus can be increased as compared to the case where a large reduction ratio is obtained by a gear train. It can be suppressed.

  Further, in the present embodiment, since a high reduction ratio can be obtained, the rotation angle of the cam member 44 with respect to the drive amount of the drive motor 51 can be reduced. Thus, the rotation angle of the cam member 44 can be finely adjusted, and fine pressure adjustment can be performed.

  In the planetary gear mechanism 70 of the present embodiment, the sun gear 62 b is an input, the internal gear 66 a is fixed, and the carrier 64 is an output. By setting the sun gear 62b input, the internal gear 66a fixed, and the carrier 64 output, the largest reduction ratio can be obtained.

  In addition, when the fixing device 12 is assembled to the apparatus main body 100, the tip of the cam gear 55 provided in the fixing device 12 may collide with the tip of the second output gear 54 provided in the apparatus main body 100. Thus, when the tooth tip of the cam gear 55 collides with the tooth tip of the second output gear 54 provided in the apparatus main body 100, the second output gear 54 rotates, and the second output gear 54 and the cam gear 55 Needs to be engaged. As described above, the drive unit 50 of the present embodiment is configured to obtain a high reduction ratio, so to transmit the force from the output side and rotate the stopped drive motor 51, It requires a great deal of power. Therefore, it is necessary to configure the drive unit 50 so that the second output gear 54 rotates to a certain extent without rotating the stopped drive motor 51.

  Therefore, in the present embodiment, as shown in FIG. 12, two driven side engagement projections 171 and two drive side engagement projections 175 are provided at an interval of 180 ° in the rotational direction, and the drive connection member 71 is a worm. It can be rotated approximately 180 ° with respect to the wheel 75. As a result, the drive transmission member on the downstream side of the drive transmission direction with respect to the worm wheel 75 (the second drive transmission member) until the drive connecting member 71 rotates approximately half turn without rotating the worm wheel 75 and rotating the stopped drive motor 51. Each member of the output gear 54, the first output gear 53, and the planetary gear mechanism 70 can be rotated. As a result, when fixing the fixing device 12 to the main assembly 100 of the apparatus, when the tip of the cam gear 55 collides with the tip of the second output gear 54, the second output can be generated without rotating the driving motor 51 during stoppage. The gear 54 rotates and the second output gear 54 and the cam gear 55 can mesh with each other. As a result, the fixing device 12 can be easily assembled without requiring a large force when assembling the fixing device 12.

FIG. 14 is a diagram showing how the pressure roller 19 is shifted from the pressure-released state (without pressure) to the pressure-applied state.
When the pressure roller 19 is in the pressure-released state, as shown in FIG. 6 (b), the top dead center of the cam member 44 where the distance from the rotation axis center of the cam member 44 to the outer peripheral surface is maximum It is in contact with the cam receiver 42. When the cam member 44 is rotated in the direction of arrow A in FIG. 14 from this state, the cam member 44 with respect to a line B connecting the contact point S1 between the cam receiver 42 and the cam surface 44b and the rotation center O1 of the cam member 44. The biasing direction F of the spring 43 received from the cam receiver 42 is shifted in the rotational direction. As a result, the biasing force of the spring 43 acts on the cam member 44 in the rotational direction of the cam member 44, the cam member 44 is pushed in the rotational direction, and the cam member 44 rotates by receiving the driving force from the drive motor 51 It rotates faster than the speed.

FIG. 15 is a view for explaining the movement of each gear of the drive unit 50 when the cam member 44 rotates faster than the rotational speed at which the cam member 44 receives the drive force from the drive motor 51 by the biasing force of the spring 43 and rotates.
The engagement portion between the drive transmission members, such as the meshing portion of the gear of the drive unit 50, has a predetermined play such as backlash. Therefore, when the cam member 44 rotates faster than the rotational drive speed by the biasing force of the spring 43, the camshaft 44a rotates with the cam member 44 faster than the rotational drive speed. As a result, as shown by arrow A2 in the figure, the cam gear 55 attached to the camshaft 44a rotates faster than the rotational driving speed. When the cam gear 55 rotates faster (backlash) with the second output gear 54, the teeth of the cam gear 55 hit the teeth of the second output gear 54 and push the second output gear 54 in the rotational direction. Then, after the second output gear 54 rotates faster by an allowance with the first output gear 53 as shown by the arrow A3 in the figure, the first output gear 53 is pushed in, and the first output gear 53 is shown in the figure. As indicated by arrow A4, the first output gear 53 is rotated faster than the rotational driving speed.

  Then, in the same manner as described above, the biasing force (hereinafter referred to as back torque) of the spring 43 is transmitted from the first output gear 53 to the planetary gear mechanism 70 and the drive connection member 71, and the drive connection member 71 Rotate faster than.

FIG. 16 (a) is a view showing a state before the drive connecting member 71 rotates faster than the rotational drive speed, and FIG. 16 (b) is a view showing the drive connecting member 71 faster than the rotational drive speed by back torque. It is a figure which shows a mode that it rotated.
As shown in FIG. 16A, when the drive connecting member 71 receives the driving force from the drive motor 51 and is rotating at the rotational driving speed, the drive side engagement projection 175 is driven from the upstream side in the rotational direction. It abuts on the side engagement protrusion 171 and transmits the driving force to the drive connecting member 71. Thus, the worm wheel 75 and the drive connecting member 71 are integrally rotated.

  As shown by arrow A6 in FIG. 16 (b), when the drive connecting member 71 is rotated faster than the rotational drive speed by the back torque, the driven side engaging projection 171 rotates so as to separate from the driving side engaging projection 175. Move in the direction.

  In the present embodiment, as described above, the play between the driven engagement protrusion 171 of the drive connection member 71 and the drive engagement protrusion 175 is approximately 180 ° in order to facilitate the assembly of the fixing device 12. . Therefore, after the drive coupling member 71 is accelerated by the back torque and the driven engagement protrusion 171 moves in the rotational direction by approximately 180 degrees, the drive engagement member 171 vigorously collides with the drive engagement protrusion 175 from the upstream side in the rotational direction. Sound may be generated.

  For this reason, in the present embodiment, a torque limiter 72 is provided as a load applying means, and a load is applied to the rotation of the drive connecting member 71 by the back torque. Specifically, the back torque is transmitted to the drive connection member 71, and when the drive connection member 71 rotates faster than the rotational drive speed, the back torque is input to the torque limiter 72 via the drive connection member 71. The torque at which the torque limiter 72 operates is set to be less than the above-mentioned back torque, and when the back torque is input to the torque limiter 72, the torque limiter 72 operates and the space between the drive connection member 71 and the drive shaft 73 Drive transmission is cut off.

  When the torque limiter 72 operates to interrupt the drive transmission, a predetermined rotational load occurs. For example, when the torque limiter 72 is a friction type, the torque limiter 72 is more than the static friction force between the first member attached to the drive shaft 73 of the torque limiter 72 and the second member attached to the drive connecting member 71. When the torque applied to is large, the second member rotates relative to the first member to block the drive transmission. Therefore, when the second member is rotated relative to the first member and the drive transmission is blocked, a predetermined frictional force is generated between the first member and the second member. , A load occurs. When the torque limiter 72 is of the magnetic type, the second member is rotated relative to the first member, and the drive transmission is blocked, in between the first member and the second member There is a predetermined magnetic force and a load is generated. As described above, when the torque limiter 72 operates to interrupt the drive transmission, a rotational load is generated. Therefore, when the back torque is transmitted to the drive connecting member 71 and rotates faster than the rotational driving speed, and the torque limiter 72 operates, a load is generated in the torque limiter 72 and the rotation of the drive connecting member 71 is braked. Thereby, after the rotation of the drive connecting member 71 is sufficiently decelerated, the driven engagement protrusion 171 collides with the drive engagement protrusion 175, and the generation of the collision sound can be suppressed.

  Further, when the cam member 44 is rotationally driven by the driving force of the drive motor 51, no torque is applied to the torque limiter 72 and the torque limiter 72 does not operate, and the biasing force of the spring 43 causes the cam member 44. Only when rotating, the torque limiter 72 operates to apply a load. As a result, the load when the cam member 44 is rotationally driven by the drive force of the drive motor 51 can be reduced, and an inexpensive motor with low output torque can be used.

  Further, in the present embodiment, even if the rotational speed of the cam member 44 is not detected by using a detection sensor or the like, a load can be applied when the cam member 44 is rapidly rotated by the urging force of the spring 43. In addition, when the cam member 44 rotates faster than a specified speed, the friction resisting member is moved and pressed against the drive connecting member 71 to apply a load, with a simple configuration, It can give a load. As a result, the load application unit 80 can be formed with an inexpensive configuration, and the cost of the apparatus can be reduced. Further, by including the torque limiter 72 by the drive side coupling 75a and the driven side coupling 71b, it is possible to suppress an increase in the size of the load applying unit 80.

  Further, in the present embodiment, the drive motor 51 is disposed so that the rotation axis direction of the drive motor 51 is orthogonal to the rotation axis direction of the sun gear 62 b of the planetary gear mechanism 70. As a result, compared to the case where the drive motor 51 is disposed so that the rotation axis direction of the drive motor 51 is parallel to the rotation axis direction of the sun gear 62b, the enlargement of the axial direction can be suppressed.

FIG. 17 is a view of the apparatus main body from the back side, and FIG. 18 is a view of the back side plate 101 from the inside of the apparatus.
As shown in FIGS. 17 and 18, the fixing device 12 as a mounting and demounting unit is detachably provided to the apparatus main body. The back side plate 101 is provided with a fixing guide 110 which guides the fixing device 12 when the fixing device 12 is attached to and detached from the apparatus main body, and holds the fixing device 12 attached to the apparatus main body. The fixing guide 110 is a resin material, and as shown in FIG. 18, has a guide groove 114 for guiding the fixing device 12. Further, the front side plate of the apparatus main body also has a fixing guide having a similar guide groove.

Guide protrusions 12 a are formed on both side surfaces of the fixing device 12. The fixing device 12 is mounted on the apparatus main body by being guided by the guide protrusions 114 of the fixing guides provided on the both side plates. When the fixing device 12 is attached to the apparatus main body, the fixing device 12 is held by the fixing guide. That is, in the present embodiment, the fixing guide holds the main body side drive transmission member such as the cam gear 55 via the fixing device 12.
Further, as shown in FIG. 17, the drive unit 50 is screwed to the fixing guide 110 and the back side plate 101.

Next, assembly of the bracket 52, the first housing 66, and the second housing 56 will be described.
FIG. 19 is an exploded perspective view of the bracket 52, the first housing 66 and the second housing 56 as viewed from the second housing 56 side. FIG. 20 shows the bracket 52, the first housing 66 and the second housing 56. It is the figure which looked at the back side surface of the apparatus main body from the apparatus back side.
The bracket 52, which is a motor holding member, is made of sheet metal and has first to fourth outer joint tightening portions 158a to 158d. The first outer joint tightening portion 158a is formed with a first outer screw through hole 151a through which a first main body fixing screw 91a for fastening the drive portion 50 to the apparatus main body penetrates. In addition, a second main body fixing screw 91c passes through a second outer screw through hole 151b through which the second main body fixing screw 91b passes through the second outer joint tightening portion 158b, and through a third outer joint tightening portion 158c. A fourth outer screw through hole 151d through which a fourth main body fixing screw 91d passes is formed in the third outer screw through hole 151c and the fourth outer joint tightening portion 158d.

  Further, the bracket 52 has two positioning protrusions 52a and 52b in which the first housing 66, which is an intermediate member, is positioned. In addition, a screw hole in which a housing attachment screw 92 for fastening the second housing 56 which is the opposing member to the bracket 52 is screwed to the second support shaft 153 on which the second output gear 54 is rotatably supported. 153a is formed.

  The second housing 56 is made of a resin material and has first to third inner joint tightening portions 157a to 157c. A first positioning screw through hole 156a for positioning the first housing 66 and passing through the first main body fixing screw 91a is formed in the first inner joint tightening portion 157a, and a second inner inner tightening portion 157b is formed. A second positioning screw through hole 156b is formed in the first housing 66 for positioning the first housing 66 and through which the second main body fixing screw 91b passes. The inner diameter of the second positioning screw through hole 156b is substantially the same diameter as the outer diameter of the second positioning projection 66b1 of the second housing 56 described later, which is the main reference for positioning, and the first positioning screw through hole 156a Is a long hole at the top and bottom, and is a substandard for positioning. In addition, the third inner joint tightening portion 157c has an inner screw through hole 156c through which the fourth main body fixing screw 91d passes.

  Further, in the second housing 56, a first main body positioning hole 56a1 which is a main body positioning portion into which the first main body positioning projection 102a provided on the back side plate 101 fits, and a second main body positioning projection provided on the back side plate 101 And a second main body positioning hole 56a2 which is a main body positioning portion into which the 102b is fitted. The inner diameter of the first main body positioning hole 56a1 is approximately the same diameter as the outer diameter of the first main body positioning projection 102a, which is the main reference for positioning, and the second main body positioning hole 56a2 has an elongated hole shape extending in the horizontal direction It is a substandard of positioning. The second housing 56 also has a mounting screw through hole 56b through which the housing mounting screw 92 passes.

  As shown in FIG. 20, the fixing guide 110 attached to the back side plate 101 is made of a resin material, and a first fastening boss 111 in which a first screw hole 111a to which the first main body fixing screw 91a is fastened is formed. A second fastening boss 112 in which a second screw hole 112a is formed to which the second body fixing screw 91b is fastened, and a third screw hole 113a in which a third body fixing screw 91c is fastened It has three fastening bosses 113.

  The back side plate 101 is formed of a sheet metal, and has two main body positioning projections 102a and 102b for positioning the second housing 56, and a fourth screw hole 103 for fastening a fourth main body fixing screw 91d.

FIG. 21 is a perspective view of the first housing 66 as viewed from the second housing side, and FIG. 22 is a cross-sectional view taken along the line E-E of FIG.
The first housing 66, which is an intermediate member, is made of a resin material and has an internal gear 66a at the center. In addition, the first housing 66 has first to third intermediate joint tightening portions 166a to 166c. A cylindrical first positioning convex portion 66b1 having a first intermediate screw through hole 161a which extends to the second housing side (the front side in the drawing) and through which the first main body fixing screw 91a penetrates the first intermediate joint tightening portion 166a. Is formed. In addition, a cylindrical second positioning convex having a second intermediate screw through hole 161b which extends to the second housing side (front side in the drawing) and through which the first main body fixing screw 91a penetrates in the second intermediate joint tightening portion 166b. A portion 66b1 is formed. Further, a third intermediate screw through hole 161c through which the third main body fixing screw 91c passes is formed in the third intermediate joint tightening portion 166c.

  Further, the first housing 66 has a first positioning hole 66c1 (see FIG. 20) in which the positioning protrusion 52a of the bracket 52 is fitted, and a second positioning hole 66c2 in which the positioning protrusion 52b is fitted. The inner diameter of the first positioning hole 66c1 is approximately the same diameter as the outer diameter of the positioning projection 52a, which is the main reference for positioning, and the second positioning hole 66c2 to be fitted is a long hole extending in the horizontal direction. It is a substandard of The first housing 66 also has an axial through hole 66 d through which the second support shaft 153 passes.

23 is a view showing a state in which the drive unit 50 is fastened to the apparatus main body, FIG. 24 is a cross-sectional view taken along line A-A of FIG. 23, and FIG. 25 is a cross-sectional view taken along line B-B of FIG. 26 is a cross-sectional view taken along the line C-C in FIG. 23, and FIG. 27 is a cross-sectional view taken along the line D-D in FIG.
The drive unit 50 is fastened to the apparatus main body 100 in a state where the second housing 56 is fastened to the second support shaft 153 by the housing attachment screw 92, as shown in FIG.
In this embodiment, the drive motor 51 is disposed so that the rotation axis direction of the drive motor 51 is orthogonal to the rotation axis direction of the sun gear 62b of the planetary gear mechanism 70, and the rotation axis direction of the drive motor 51 is as shown in FIG. As shown in FIG. 2, it is parallel to the back side plate 101. As a result, the gap between the back side plate 101 and the exterior cover of the printer can be narrowed as compared with the case where the rotation axis direction of the drive motor 51 is orthogonal to the back side plate 101, and the printer can be miniaturized. Can.

  As shown in the B1 enlarged view of FIG. 25, the tip end of the second support shaft 153 has a small diameter, and the second housing 56 has a step of the second support shaft 153 and a head of a screw 92 for housing attachment. It is fastened in the form of being pinched. As described above, the second support shaft 153 and the first support shaft 152 are fixed by fastening the drive unit 50 to the apparatus main body 100 in a state where the second housing 56 is fixed to the bracket 52 via the second support shaft 153. The drive transmission member (the second output gear 54, the first output gear 53, etc.) rotatably supported slips out from the second support shaft 153 or the first support shaft 152 when the drive unit 50 is assembled to the apparatus main body 100. Can be prevented. Thus, the drive unit 50 can be easily fastened to the apparatus body 100.

  Further, by fastening the second housing 56 to the bracket 52 via the second support shaft 153, the positioning projection 52a of the bracket 52 is fitted in the positioning hole 66c1 of the first housing 66 as shown in the C3 enlarged view of FIG. As shown in an enlarged view of B2 in FIG. 25, the positioning projection 52b is fitted in the positioning hole 66c2, and the first housing 66 is positioned on the bracket 52. The first housing 66 is positioned on the bracket 52 to support the axial center of the internal gear 66 a provided on the first housing and the plurality of planet gears 65 supported by the first support shaft 152 of the bracket 52. The axial center of the carrier can be matched. Thereby, the internal gear 66a and the plurality of planetary gears can be meshed with high accuracy.

  Further, as shown in the C1 enlarged view and the C2 enlarged view of FIG. 26, the positioning convex portions 66b1 and 66b2 of the first housing 66 fit into the positioning screw through holes 156a and 156b of the second housing 56, and The second housing 56 is positioned. Thereby, the bracket 52 is positioned in the second housing 56 via the first housing 66.

  Thus, by positioning the bracket 52, the first housing 66 and the second housing 56, the outer screw through holes 151a, 151b, 151c, 151d of the bracket 52 and the intermediate screw through holes of the first housing 66 are obtained. 161a, 161b, 161c and the screw through holes 156a, 156b, 156c of the second housing 56 can be overlapped. Thus, the drive unit 50 can be easily fastened to the apparatus main body 100 by the main body fixing screws 91a, 91b, 91c, and 91d.

  The drive transmission member rotatably supported by the second support shaft 153 and the first support shaft 152 when the drive unit 50 is assembled to the apparatus main body is fastened to the second housing 56 by the housing attachment screw 92. This is done to prevent the one output gear 53, the second output gear 54, etc. from coming out, and to keep the bracket 52, the first housing 66 and the second housing 56 positioned relative to each other. Therefore, it is not necessary to keep the second housing 56 completely immovable in the axial direction, and it may be possible that the second housing 56 has some axial play. Therefore, the axial length of the small diameter portion formed at the tip of the second support shaft 153 may be rough and the tip of the second support shaft 153 may slightly protrude from the mounting screw through hole 56b. Further, the small diameter portion may not be provided at the tip of the second support shaft 153. Even if the small diameter portion is not provided at the tip of the second support shaft 153, the second housing 56 can be fixed to the bracket 52 by the housing attachment screw 92 in a state where it can move slightly in the axial direction. In addition, since it is not necessary to form a small diameter portion at the tip of the second support shaft 153 such as cutting, the manufacturing cost can be reduced.

  Further, in the present embodiment, the second housing 56 is fixed by the housing attachment screw 92. However, the present invention is not limited to this. The second housing 56 may be fixed to the bracket 52 by a snap fit or the like.

  In this manner, the drive unit 50 in a state in which the bracket 52, the first housing 66 and the second housing 56 are positioned and assembled to each other by the housing attachment screw 92 is fastened to the apparatus body 100. Specifically, first, the main body positioning holes 56a1 and 56a2 of the second housing 56 are inserted into the main body positioning projections 102a and 102b provided on the back side plate 101 to position the drive unit 50 with respect to the apparatus main body (see FIG. 24 A1 enlarged view, see D1 enlarged view of FIG. 27). The bracket 52 holding the second output gear 54 and the like is positioned in the second housing 56 via the first housing 66. Therefore, by positioning the drive unit 50 on the apparatus main body by the main body positioning holes 56a1 and 56a2 of the second housing 56, the second output gear 54 can be positioned at the target position of the apparatus main body. Thereby, the second output gear 54 can be engaged with the cam gear 55 which is the main body side drive transmission member with high accuracy.

  The second output gear 54 can also be positioned at the target position of the apparatus body by directly positioning the bracket 52 holding the second output gear 54 in the apparatus body 100. However, if the bracket 52 is directly positioned on the apparatus main body 100 for the following reason, there arises a problem that the drive unit 50 is enlarged. That is, the drive unit 50 according to the present embodiment includes the planetary gear mechanism 70, and the internal gear 66a including the plurality of planetary gears and the sun gear inevitably becomes large. As a result, the first housing 66 having the internal gear 66a also becomes large. Therefore, when the bracket 52 is directly positioned in the apparatus main body, the positioning structure for positioning the bracket 52 and the apparatus main body needs to be provided on the outside of the first housing 66, and the drive unit 50 becomes large. is there.

  On the other hand, as in the present embodiment, the bracket 52 and the first housing 66 are positioned, the first housing 66 and the second housing 56 are positioned, and the body positioning holes 56a1 and 56a2 provided in the second housing 56. By positioning the drive unit 50 in the apparatus main body, the second output gear 54 can be positioned at the target position of the apparatus main body while suppressing an increase in size of the drive unit 50.

  As described above, when the drive unit 50 is positioned in the apparatus main body, the drive unit 50 is fastened to the apparatus main body 100 by the main body fixing screws 91 a to 91 d. Specifically, the first main body fixing screw 91 a is screwed into the first screw hole 111 a of the first fastening boss 111. Thus, the first outer joint tightening portion 158a of the bracket 52, the first intermediate common tightening portion 166a of the first housing 66, and the first inner common tightening portion 157a of the second housing 56 are fixed by the first main body fixing screw 91a. The fixing guide 110 is fastened together. Further, the second main body fixing screw 91 b is screwed into the second screw hole 112 a of the second fastening boss 112. Thereby, the second outer joint tightening portion 158b of the bracket 52, the second intermediate common tightening portion 166b of the first housing 66, and the second inner common tightening portion 157b of the second housing 56 are formed by the second main body fixing screw 91b. The fixing guide 110 is fastened together. Further, the third main body fixing screw 91 c is screwed into the third screw hole 113 a of the third fastening boss 113. As a result, the third outer joint tightening portion 158 c of the bracket 52 and the third intermediate common tightening portion 166 c of the first housing 66 are jointed to the fixing guide 110 by the first main body fixing screw 91 a. Furthermore, the fourth main body fixing screw 91 d is screwed into the fourth screw hole 103 of the back side plate 101. As a result, the fourth outer joint tightening portion 158 d of the bracket 52 and the third inner common tightening portion 157 c of the second housing 56 are jointed to the back side plate 101 by the fourth main body fixing screw 91 d.

  Thus, the first housing 66 is fastened to the bracket 52 by fastening the bracket 52, the first housing 66, and the second housing 56 together, and the second housing 56 is fastened to the first housing 66, Compared with the conventional configuration in which any one of the bracket 52, the first housing 66 and the second housing 56 is fastened to the apparatus main body, the enlargement of the drive unit 50 is suppressed, the cost is reduced by the reduction of the number of parts, and the number of assembling steps is reduced The manufacturing cost can be reduced. The reasons are described below.

  As described above, the internal gear 66a of the planetary gear mechanism 70 has a large diameter. In the conventional configuration in which the first housing 66 is fastened to the bracket 52 and the second housing 56 is fastened to the first housing 66, the bracket 52 is fastened to the first housing 66 having the large-diameter internal gear 66a. And a fastening portion to which the second housing 56 is fastened. Further, it is necessary to provide the first housing 66 with a positioning portion for positioning on the bracket 52 and a positioning portion for positioning the second housing 56. As a result, the large first housing 66 having the large diameter internal gear 66a becomes larger, and the apparatus becomes larger. In addition, a screw for fastening the first housing 66 to the bracket 52, a screw for fastening the second housing 56 to the first housing 66, and a screw for fastening the drive unit 50 to the apparatus main body are required. Will increase. Furthermore, there are steps of fastening the first housing 66 to the bracket 52, fastening the second housing 56 to the first housing 66, and fastening the drive unit 50 to the apparatus main body, which requires many assembling steps.

  On the other hand, in the present embodiment, three intermediate joint tightening portions 166a, 166b and 166c, positioning portions (positioning holes 66c1 and 66c2) for positioning on the bracket 52, and the second housing 56 are positioned in the first housing 66. The bracket 52, the first housing 66, and the second housing 56 can be positioned and fastened to each other by providing positioning portions (positioning convex portions 66b1 and 66b2). Thus, the increase in size of the first housing 66 can be suppressed, and the increase in size of the drive unit 50 can be suppressed, as compared with the conventional configuration described above.

  Further, in the present embodiment, the bracket 52, the first housing 66 and the second housing 56 can be fastened by the four screws of the first to fourth main body fixing screws 91a to 91d, as compared with the conventional configuration. The number of screws can be reduced. Further, the bracket 52, the first housing 66, and the second housing 56 can be fastened to each other by fastening the drive unit 50 to the apparatus main body with the four body fixing screws 91a to 91d. As compared with the configuration, the number of assembling steps can be reduced.

  Further, as shown in FIG. 21 and the like, the first housing 66 is fastened on both sides with the internal gear 66a interposed therebetween. As a result, the first housing 66 can be stably fastened without rattling, and the internal gear 66a can be meshed with the plurality of planetary gears 65 in a favorable manner.

  Further, the fourth main body fixing screw 91d is made of metal and is fastened to the back side plate 101 made of a sheet metal. Thus, the drive motor 51 can be grounded via the bracket 52 made of a sheet metal, the fourth main body fixing screw 91 d, and the back side plate 101 made of a sheet metal. This can suppress the occurrence of an adverse effect on the operation of the drive motor 51.

  Further, in the present embodiment, the first housing 66 has an axial through hole 66d through which the second support shaft 153 penetrates, and as shown in FIG. It is made to face the supported second output gear 54. Thus, the movement of the second output gear 54 to the bracket side can be restricted by the first housing 66, and the second output gear 54 can be meshed with the cam gear 55.

  Further, in the present embodiment, the positioning convex portions 66b1 and 66b2 in which the second housing 56 is positioned are made cylindrical and the screw through holes through which the main body fixing screws 91a and 91b penetrate are formed in the positioning convex portions 66b1 and 66b2. It is provided. Thus, the first housing 66 can be made smaller than that in which the positioning convex portions 66b1 and 66b2 for positioning the second housing 56 and the screw through holes through which the body fixing screws 91a and 91b penetrate are provided at different positions. The drive unit 50 can be miniaturized.

  Further, either one of the positioning portions of the first housing 66 and the bracket 52 may have a cylindrical shape having screw through holes through which the body fixing screws 91a and 91b pass, as in the positioning portion with the second housing. . Thereby, the diameter increase of the first housing 66 can be further suppressed, and the miniaturization of the drive unit 50 can be further achieved.

  Further, in the present embodiment, in positioning of the first housing 66 and the second housing 56, a positioning screw having a cylindrical positioning convex portion on the first housing 66 and a positioning convex portion fitted on the second housing 56 Although the through hole is provided, a cylindrical positioning protrusion may be provided in the second housing 56, and a positioning screw through hole may be provided in the first housing 66.

FIG. 28 shows a modification of the bracket 52. As shown in FIG.
In the modification shown in FIG. 28, the fourth outer joint tightening portion 158 d is provided on the lower side than the rotation axis center of the drive motor 51. Thus, by providing the fourth outer joint tightening portion 158 d on the lower side than the rotation axis center of the drive motor 51, the bracket 52 sandwiches the rotation axis center of the drive motor 51 on one side and the other side. It is concluded with For example, when the bracket 52 is fastened only on one side across the rotation axis center of the drive motor 51, the other side of the bracket 52 has a cantilever support form, and the other side may vibrate due to the vibration of the drive motor 51. is there.

  On the other hand, as shown in FIG. 28, by fastening the bracket 52 on both the one side and the other side of the rotational axis center of the drive motor 51, the vibration of the drive motor 51 suppresses the vibration of the bracket 52. be able to.

  Further, in the example shown in FIG. 28, the bracket 52 is fastened at four places, but the bracket 52 is fastened at three places of two places on one side and one place on the other side across the rotation axis center of the drive motor 51 You may

The above-described one is an example, and each mode has the unique effect.
(Aspect 1)
A drive source such as the drive motor 51 and a plurality of drive transmission members for transmitting the drive force of the drive source to the drive member such as the cam member 44 (in this embodiment, each of the worm gear 60, the worm wheel 75, and the planetary gear mechanism 70 Gear, first output gear 53 and second output gear 54), a drive source holding member such as a bracket 52 for holding a drive source, and a second housing facing the drive source holding member with at least one drive transmission member interposed therebetween An opposing member such as 56, and disposed between the drive source holding member and the opposing member, positioned on at least one of the drive source holding member and the opposing member, and having one of a plurality of the drive transmission members In the drive unit such as the drive unit 50 provided with an intermediate member such as the first housing 66, the intermediate member and the one member (in the present embodiment, the second housing) 6) a main body fixing screw 91a of the positioning portion for positioning the fastening member penetrates the like 91b, and the driving source holding member and the intermediate member and the opposing member is fastened to said body unit in fastened.
According to this, the positioning of at least one of the drive source holding member and the opposing member and the intermediate member, the fixing of the drive source holding member, the opposing member and the intermediate member, and the fixation to the main device are coaxial. It takes place. As a result, the drive source holding member, the opposing member, and the intermediate member are fixed outside the positioning portion between the intermediate member and at least one member of the driving source holding member and the opposing member, and further to the main device at the outside. As compared with the drive device described in Patent Document 1 in which fixation is performed, the device can be miniaturized.

(Aspect 2)
In the first aspect, the positioning portion is provided on one of the intermediate member such as the first housing 66 and the one member (the second housing 56 in the present embodiment), and the fastening members such as the main body fixing screws 91a and 91b Cylindrical positioning convex parts 66b1 and 66b2 having through holes such as intermediate screw through holes 161a and 161b to penetrate and the positioning through holes such as positioning screw through holes 156a and 156b provided on the other and the positioning convex parts are fitted According to this configuration, as described in the embodiment, the positioning members can penetrate the fastening members such as the main body fixing screws 91a and 91b.

(Aspect 3)
In the aspect 1 or 2, the opposing member such as the second housing 56 is fixed to the drive source holding member such as the bracket 52.
According to this, as described in the embodiment, when the drive device such as the drive unit 50 is attached to the main device such as a printer, it is possible to prevent the drive transmission member from being detached from the drive device. Thus, the work of assembling the drive device to the main body device can be easily performed.

(Aspect 4)
In any one of the modes 1 to 3, the opposing member such as the second housing 56 has a main body positioning portion such as main body positioning holes 56a1 and 56a2 positioned with respect to the main body device.
According to this, it can mesh | engage favorably with the drive transmission members of main body apparatuses, such as a cam gear.

(Aspect 5)
In any one of the aspects 1 to 4, the one member is an opposing member such as a second housing.
According to this, an intermediate member such as the first housing 66 can be positioned in the second housing 56.

(Aspect 6)
In any one of the first to fifth aspects, an intermediate member such as the first housing 66 is positioned on a drive source holding member such as the bracket 52 and an opposing member such as the second housing 56.
According to this, it is possible to position the intermediate member such as the first housing 66 or the like, the drive source holding member such as the bracket 52, and the opposite member such as the drive source holding member and the second housing 56 to each other.

(Aspect 7)
In any one of the aspects 1 to 6, the drive transmission member held by the intermediate member such as the first housing 66 is an internal gear.
As described in the embodiment, in the intermediate member such as the first housing 66 including the internal gear, it is necessary to provide the positioning portion and the fastening portion on the outer shell of the internal gear, and the intermediate member becomes large. There is a possibility that the drive device of a drive part may enlarge.
However, in the present aspect, since the configuration of aspect 1 is provided, enlargement of the intermediate member can be effectively suppressed.

(Aspect 8)
In any one of the aspects 1 to 7, the planetary gear mechanism 70 is provided.
According to this, the enlargement of the drive device of the drive unit 50 can be suppressed, and a large reduction ratio can be obtained. In addition, even if an inexpensive drive source with low torque is used as a drive source for the drive motor 51 or the like, the drive member such as the cam member 44 can be favorably driven.

(Aspect 8)
In the seventh embodiment, the sun gear 62 b of the planetary gear mechanism 70 and the carrier 64 for holding the plurality of planetary gears 65 are supported by the shaft of a drive source holding member such as the first support shaft 152. The tooth gear 66 a is provided on an intermediate member such as the first housing 66.
As described in the embodiment, since the internal gear 66a of the planetary gear mechanism 70 includes the plurality of planetary gears 65 and the sun gear 62b, the diameter increases, and the first housing 66 also increases accordingly. . However, in the present aspect, since the configuration of aspect 1 is provided, the increase in size of the intermediate member can be effectively suppressed, and the increase in size of the drive device such as the drive unit 50 can be suppressed.

(Aspect 9)
In aspect 7 or 8, the rotation axis direction of the sun gear 62b of the planetary gear mechanism 70 and the rotation axis direction of the drive source such as the drive motor 51 are orthogonal to each other.
According to this, as described in the embodiment, compared with the case where the rotation axis direction of the drive source such as the drive motor 51 is parallel to the rotation axis direction of the sun gear 62b, the sun of the drive device such as the drive unit 50 is It is possible to suppress an increase in size in the rotation axis direction of the gear 62b.

(Aspect 10)
In aspect 9, the rotational axis direction of the drive source such as the drive motor 51 is parallel to a side plate such as the back side plate 101 to which the drive device of the main device is fastened.
According to this, as described in the embodiment, the rotational axis direction of the driving source such as the driving motor 51 is orthogonal to the side plate such as the back side plate 101 to which the driving device of the main device is fastened. The direction orthogonal to the side plate of the drive can be shortened. As a result, the gap between the exterior cover of the main device such as a printer and the back side plate 101 can be narrowed, and the main device can be miniaturized.

(Aspect 11)
In any of the first to tenth aspects, the intermediate member such as the first housing 66 is fixed only by co-clamping.
According to this, it is possible to reduce the number of fastening members such as screws, and to reduce the cost of the drive device.

(Aspect 12)
In any one of the first to eleventh aspects, the fixing guide for holding the drive transmission member disposed in the main device, the opposing member such as the second housing 56, the intermediate member such as the first housing 66, and the drive source holding member such as the bracket 52. It is fastened together to a member such as 110.
According to this, the drive transmission member such as the second output gear 54 meshing with the drive transmission member such as the cam gear 55 disposed in the main device of the drive device such as the drive unit 50 is a drive transmission member disposed in the main device It can mesh well.

(Aspect 13)
In any one of the first to twelfth aspects, the drive source holding member such as the bracket 52 is made of metal, and a fourth outer joint tightening portion to be fastened to a metal member (the back side plate 101 in the present embodiment) of the main device. It has a fastening part such as 158 d.
According to this, as described in the embodiment, the driving source such as the driving motor 51 can be electrically grounded via the bracket, the fastening member, and the metal member of the main device.

(Aspect 14)
In any one of the first to thirteenth aspects, the drive source holding member such as the bracket 52 has fastening portions such as three or more outer joint tightening portions, and one of the plurality of fastening portions is a rotation shaft of the drive source. It was provided on the opposite side of the side where the other fastening part was provided across the center.
According to this, as described with reference to FIG. 28, it is possible to suppress that the drive source holding member such as the bracket 52 vibrates due to the vibration at the time of driving the drive source of the drive motor 51.

(Aspect 15)
An image forming apparatus including a driving member such as a cam member 44 and a driving device for driving the driving member and forming an image on a recording medium such as a sheet material P, the driving device described in any one of aspects 1 to 14 The drive of was used.
According to this, it is possible to miniaturize the image forming apparatus.

(Aspect 16)
In the fifteenth embodiment, the drive unit such as the cam member 44 is provided, and a mounting unit such as the fixing device 12 that can be mounted to and detached from the apparatus body, and a guide groove 114 that guides the mounting unit when the mounting unit is mounted and detached. And a guide holding member such as a fixing guide 110 for holding the mounting / demounting unit, and the opposing member, the intermediate member, and the drive source holding member are fastened together by the guide holding member. .
According to this, the driving force of the driving source such as the driving motor 51 can be transmitted to the driving member such as the cam member 44 of the mounting and demounting unit such as the fixing device 12 favorably.
The mounting / demounting unit is not limited to the fixing device 12, and may be a process cartridge 1, a transfer device, or the like as long as it can be detachably mounted to the apparatus main body.

(Aspect 17)
In the sixteenth aspect, the attaching / detaching unit is the fixing device 12.
According to this, the driving force can be favorably transmitted to the driving member such as the cam member 44 of the fixing device 12.

1: Process cartridge 2: Photoconductor 3: Charging roller 4: Development device 5: Cleaning blade 6: LED head array 7: Toner cartridge 8: Developer storage unit 9: Developer collection unit 10: Transfer unit 11: Paper feeding device 12: fixing device 12a: guide projection 13: paper discharge device 14: transfer roller 15: paper feed cassette 16: paper feed roller 17: registration roller 18: fixing roller 19: pressure roller 19a: shaft 20: paper discharge roller 21 A discharge tray 22: container main body 23: infrared heater 30: transfer frame 37: opening / closing cover 40: pressure adjusting mechanism 41: lever member 41a: support shaft 41b: spring receiver 42: cam receiver 43: spring 44: cam member 44a : Cam shaft 44 b: Cam surface 44 c: Parallel pin 45: Rotation angle detection mechanism 45 a: F Roller 45b: Optical sensor 45c: Opening 46: Bearing 47: Side plate 47a: Spring receiver 50: Drive unit 51: Drive motor 51a: Screw hole 52: Bracket 52a: Positioning projection 52b: Positioning projection 53: First output gear 54: Second output gear 55: Cam gear 55a: Parallel pin 56: Second housing 56a1: First main body positioning hole 56a2: Second main body positioning hole 56b: Mounting screw through hole 60: Worm gear 61: Worm 62: Planetary drive transmission member 62a : Input gear 62b: Sun gear 63: Carrier holder 63a: Snap fit portion 64: Carrier 64a: Supported portion 64b: Engagement hole 64c: Planet support portion 65: Planet gear 66: First housing 66a: Internal gear 66b1 : First positioning projection 66b 2: Second positioning projection 66 c1: first positioning hole 66c2: second positioning hole 66d: shaft through hole 70: planetary gear mechanism 71: drive connecting member 71a: gear portion 71b: driven side coupling 71c: engagement hole 72: torque limiter 72a: cut Notched part 72b: Engaging projection 73: Drive shaft 73a: Press fit part 73b: Support part 74: Parallel pin 75: Worm wheel 75a: Drive side coupling 75c: Press fit hole 80: Load applying part 91a: For fixing the first main body Screw 91b: Second main body fixing screw 91c: Third main body fixing screw 91d: Fourth main body fixing screw 92: Housing mounting screw 100: Device main body 101: Back side plate 102a: First main body positioning projection 102b: First Two main body positioning projection 103: fourth screw hole 110: fixing guide 111: first fastening boss 111a: first Screw holes 112: second fastening boss 112a: second screw hole 113: third fastening boss 113a: third screw hole 114: guide groove 151a: first outer screw through hole 151b: second outer screw through hole 151c: third Outer screw through hole 151d: fourth outer screw through hole 152: first support shaft 153: second support shaft 153a: screw hole 154: bearing 155: motor holding surface 155a: notch 155b: screw through hole 156a: first positioning Screw through hole 156b: second positioning screw through hole 156c: inner screw through hole 157a: first inner joint tightening portion 157b: second inner joint tightening portion 157c: third inner joint tightening portion 158a: first outer joint tightening portion 158b : Second outer joint tightening portion 158c: third outer joint tightening portion 158d: fourth outer joint tightening portion 161a: first middle screw through hole 161b: first Middle screw through hole 161c: third middle screw through hole 164: drive connection convex portion 166a: first middle joint tightening portion 166b: second middle joint tightening portion 166c: third middle joint tightening portion 171: follower side engagement protrusion 175 : Drive side engagement protrusion P: Sheet material

JP 2012-82842 A

Claims (18)

Driving source,
A plurality of drive transmission members for transmitting the drive force of the drive source to the drive member;
A drive source holding member for holding the drive source;
An opposing member facing the drive source holding member with at least one drive transmission member interposed therebetween;
An intermediate member disposed between the drive source holding member and the opposite member, positioned on at least one of the drive source holding member and the opposite member, and having one of a plurality of the drive transmission members; In the drive provided,
A fastening member passes through a positioning portion for positioning the intermediate member and the one member, and the drive source holding member, the intermediate member, and the opposing member are fastened together to the main device by tightening. Drive device. In the drive device according to claim 1,
The positioning portion is provided on one of the intermediate member and the one member, and is provided on the other of a cylindrical positioning convex portion having a through hole through which the fastening member passes, and the positioning convex portion is fitted And a positioning through hole. In the drive device according to claim 1 or 2,
The said opposing member is clamped by the said drive source holding member, The drive device characterized by the above-mentioned. The drive device according to any one of claims 1 to 3.
The said opposing member has a main body positioning part positioned with respect to a main body apparatus, The drive device characterized by the above-mentioned. The drive device according to any one of claims 1 to 4.
The driving device according to claim 1, wherein the one member is the opposing member. In the drive device according to any one of claims 1 to 5,
The driving device is characterized in that the intermediate member is positioned on the drive source holding member and the opposing member. In the drive device according to claim 6,
A drive unit characterized in that the drive transmission member of the intermediate member is an internal gear. The drive device according to any one of claims 1 to 7.
A driving device having a planetary gear mechanism. In the drive device according to claim 8,
A drive device characterized in that a drive transmission member of the intermediate member is an internal gear of the planetary gear mechanism. In the drive device according to claim 8 or 9,
A driving device characterized in that a rotation axis direction of a sun gear of the planetary gear mechanism and a rotation axis direction of the drive source are orthogonal to each other. In the drive device according to claim 10,
A driving device characterized in that a rotation axis direction of the driving source is parallel to a side plate to which the driving device of the main device is fastened. The driving device according to any one of claims 1 to 11.
The driving device according to claim 1, wherein the intermediate member is fixed only by co-tightening. The driving device according to any one of claims 1 to 12.
A driving device characterized in that the driving source holding member, the intermediate member, and the opposing member are fastened together by a member for holding a driving force transmission member disposed in the main body device. The drive device according to any one of claims 1 to 13.
The drive source holding member is made of metal and has a fastening portion to be fastened to a metal member of the main body device. In the drive device according to any one of claims 1 to 14,
The drive source holding member has three or more fastening parts, and one of the plurality of fastening parts is opposite to the side on which the other fastening part is provided with the rotation axis center of the drive source interposed therebetween. A driving device characterized in that it is provided. A driving member,
An image forming apparatus for forming an image on a recording medium, comprising: a driving device for driving the driving member;
An image forming apparatus using the driving device according to any one of claims 1 to 15 as the driving device. In the image forming apparatus according to claim 16,
An attachable / detachable unit having the drive member and attachable to and detachable from the apparatus main body;
It has a guide portion for guiding the mounting and demounting unit when mounting and demounting the mounting and demounting unit, and includes a guide holding member for holding the mounting and demounting unit,
2. The image forming apparatus according to claim 1, wherein the facing member, the intermediate member, and the drive source holding member are fastened together to the guide holding member. In the image forming apparatus according to claim 17,
The image forming apparatus, wherein the mounting and demounting unit is a fixing device.

Images