JP6075274B2 - Developer cartridge and process cartridge - Google Patents

Description

  The present invention relates to a developing cartridge and a process cartridge mounted on an image forming apparatus that employs an electrophotographic system.

  2. Description of the Related Art As an electrophotographic image forming apparatus, there is known a printer that is detachably provided with a developing cartridge having a developing roller and a supply roller.

  As a developing cartridge that is detachably attached to such a printer, a developing gear and a supply gear that are disposed at the end portions of the developing roller and the supply roller, respectively, and to which driving force from the outside is transmitted, are integrated with them. A developing cartridge including a gear cover for covering is known (for example, see Patent Document 1).

JP 2011-133663 A

  However, in the developing cartridge described in Patent Document 1 described above, since the entire developing gear and the supply gear are covered with the gear cover, the gear cover is enlarged. Therefore, there is a problem that the developing cartridge is increased in size.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developing cartridge and a drum cartridge that can cover the first gear and the second gear and can be reduced in size.

(1) In order to achieve the above-described object, the developing cartridge of the present invention is configured to rotate about a housing configured to accommodate the developer therein and a first axis extending in the first direction. A developer carrier and a supply configured to rotate about a second axis parallel to the first axis and configured to contact the developer carrier and supply developer to the developer carrier A gear cover configured to cover the member, a first gear coupled to the end of the developer carrier, a second gear coupled to the end of the supply member, and the first gear and the second gear A first cover portion extending in a direction orthogonal to the first direction, and a gear cover connected to the first cover portion and including a second cover portion extending in the first direction, wherein the second cover portion is An opening exposing a portion of the second gear, and a portion of the second gear is open. Through, and protrudes from the second cover portion.

  According to such a configuration, both the first gear and the second gear are covered by the first covering portion and the second covering portion of the gear cover so that a part of the second gear is exposed. , Protruding from the opening of the second covering portion.

  Therefore, since the second covering portion has the opening from which the second gear projects, the size of the gear cover in the direction orthogonal to the first direction can be reduced.

As a result, both the first gear and the second gear can be protected by the gear cover, and the developing cartridge can be reduced in size.
(2) Moreover, the 1st coating | coated part may coat | cover all the end surfaces of the 1st direction of a 2nd gear.

  According to such a configuration, part of the second gear protrudes from the second covering portion, whereas all end faces in the first direction of the second gear are covered by the first covering portion. Yes.

Therefore, it is possible to reliably protect the end surface of the second gear in the first direction while reducing the size of the developing cartridge.
(3) Further, a third gear that meshes with both the first gear and the second gear is provided, and the meshing portion between the third gear and the first gear is in relation to the meshing portion between the third gear and the second gear. , And may be shifted along the first direction.

  According to such a structure, grease can be apply | coated to a 2nd gear through opening of a 2nd coating | coated part.

  Furthermore, since the first gear and the second gear are displaced along the first direction, it is possible to apply grease to the first gear through the opening of the second covering portion.

Therefore, grease can be efficiently applied to both the first gear and the second gear through the opening of the second covering portion.
(4) Further, the third gear is configured to rotate about a third axis parallel to both the first axis and the second axis, and the supply member includes a rotating shaft, and is viewed from the first direction. When an imaginary line passing through the third axis is imagined along the direction in which the two gears protrude from the second covering portion, the rotation axis may be arranged closer to the developer carrier than the imaginary line.

  According to such a configuration, the first gear coupled to the developer carrying member and the second gear coupled to the supply member can be disposed so as to be relatively close to each other.

Therefore, the developer carrying member and the supply member can be arranged at appropriate positions in the developing cartridge, and the developing cartridge can be reduced in size.
(5) Further, the housing includes a protruding portion that protrudes in a direction in which the second gear protrudes from the second covering portion when viewed from the first direction, and the protruding portion has the second gear in the first direction. May be arranged next to each other.

  According to such a configuration, the second gear can be protected by the protrusion in the direction in which the protrusion and the second gear are adjacent to each other.

Therefore, even if a part of the second gear protrudes from the opening of the second covering portion, the second gear can be protected more reliably.
(6) The process cartridge of the present invention is a process cartridge including a developing cartridge and a photosensitive cartridge to which the developing cartridge is detachably mounted, and the photosensitive cartridge rotates about an axis along the first direction. And a cartridge mounting portion to which the developing cartridge is mounted. The cartridge mounting portion includes a bottom portion facing the second gear in a direction in which the second gear protrudes from the second covering portion. And an engaging hole for engaging with the protruding portion.

  According to such a configuration, when the developing cartridge is mounted in the cartridge mounting portion, the bottom portion can protrude from the opening and protect a part of the exposed second gear, while the protruding portion is used as the engagement hole. By engaging, the developing cartridge can be easily positioned with respect to the drum cartridge.

  Further, the developing cartridge is increased in size in the direction in which the second gear protrudes because the protruding portion protrudes from the housing. However, when the developing cartridge is attached to the drum cartridge, the protruding portion is inserted into the engagement hole. Therefore, an increase in the size of the process cartridge can be suppressed.

  According to the developing cartridge and the drum cartridge of the present invention, the first gear and the second gear can be covered, and the size can be reduced.

FIG. 1 is a central sectional view of a developing cartridge according to an embodiment of the present invention. 2 is a central sectional view of the image forming apparatus to which the developing cartridge shown in FIG. 1 is mounted. 3A is a left side view of the developing cartridge shown in FIG. FIG. 3B is a left side view of the developing cartridge shown in FIG. 3A with the gear cover removed. FIG. 4 is a perspective view of the developing cartridge shown in FIG. 3A as viewed from the lower left. FIG. 5 is an exploded perspective view of the developing cartridge shown in FIG. 3A as viewed from the lower left with the gear cover removed. 6 is a bottom view of the developing cartridge shown in FIG. 3A. FIG. 4 is an explanatory diagram for explaining assembly of the developing cartridge to the drum cartridge according to the embodiment of the present invention, and is a perspective view of the drum cartridge and the developing cartridge as viewed from the upper right. FIG. 8 is a perspective view of the process cartridge shown in FIG. 2 as viewed from the upper right. 9 is a cross-sectional view taken along the line AA in FIG.

1. 1. Overview of Developing Cartridge As shown in FIG. 1, the developing cartridge 1 includes a developing frame 2 as an example of a housing, an agitator 3, a developing roller 4 as an example of a developer carrier, and an example of a supply member. A supply roller 5 and a layer thickness regulating blade 6 are provided.

  In the following description, when referring to the direction of the developing cartridge 1, the direction where the developing roller 4 is disposed is the rear of the developing cartridge 1, and the opposite is the front of the developing cartridge 1. That is, the left side of FIG. 1 is the rear side of the developing cartridge 1, and the right side of the page is the front side of the developing cartridge 1. 1 is the upper side of the developing cartridge 1, and the lower side of the paper is the lower side of the developing cartridge 1. In addition, when the developing cartridge 1 is viewed from the front, the left and right reference is used. That is, the front side of the sheet of FIG. 1 is the left side of the developing cartridge 1, and the back side of the sheet is the right side of the developing cartridge 1. The left-right direction is an example of the first direction, the up-down direction is an example of the second direction, and the front-back direction is an example of the third direction. Specifically, with respect to the direction of the developing cartridge 1, the arrow direction shown in each drawing is used as a reference.

  The developing frame 2 has a substantially box shape extending in the left-right direction, and the rear end portion of the developing frame 2 is opened in the front-rear direction. Further, the developing frame 2 has a toner storage chamber 7 and a developing chamber 8 as an example of a developer storage chamber arranged in parallel in the front-rear direction. The toner storage chamber 7 stores toner as an example of a developer.

  The agitator 3 is disposed at a substantially central portion in the front-rear and up-down directions of the toner storage chamber 7. The agitator 3 includes an agitator shaft 9 and a stirring blade 10.

  The agitator shaft 9 has a substantially cylindrical shape extending in the left-right direction. Both end portions in the left-right direction of the agitator shaft 9 protrude outward in the left-right direction from a left side wall 34 and a right side wall 35 to be described later.

  The stirring blade 10 extends from the agitator shaft 9 outward in the radial direction of the agitator shaft 9.

  And the agitator 3 is comprised so that it may rotate centering | focusing on the agitator center axis line A1 which is the center of the agitator axis | shaft 9. FIG.

  The developing roller 4 is disposed at the rear end of the developing chamber 8. The developing roller 4 includes a developing roller shaft 11 and a developing roller main body 12.

  The developing roller shaft 11 is made of metal and has a substantially cylindrical shape extending in the left-right direction. Both end portions in the left-right direction of the developing roller shaft 11 protrude outward in the left-right direction from a left side wall 34 and a right side wall 35 to be described later.

  The developing roller main body 12 is made of conductive rubber and has a substantially cylindrical shape extending in the left-right direction. The developing roller body 12 does not cover both ends of the developing roller shaft 11 in the left-right direction, and covers the substantially center of the developing roller shaft 11 in the left-right direction. Further, the upper part and the rear part of the developing roller main body 12 are exposed from the developing frame 2.

  The developing roller 4 is configured to rotate around the developing roller center axis A2 that is the center of the developing roller shaft 11. The developing roller central axis A2 is an example of a first axis.

  The supply roller 5 is disposed in the developing chamber 8 at the front lower side of the developing roller 4. More specifically, the supply roller 5 is disposed in front of and below the developing roller central axis A2. The supply roller 5 includes a supply roller shaft 13 as an example of a rotation shaft, and a supply roller main body 14.

  The supply roller shaft 13 is made of metal and has a substantially cylindrical shape extending in the left-right direction. Both end portions in the left-right direction of the supply roller shaft 13 protrude in the left-right direction from each of a left side wall 34 and a right side wall 35 described later.

  The supply roller main body 14 is made of a conductive sponge and has a substantially cylindrical shape extending in the left-right direction. The supply roller main body 14 does not cover both ends of the supply roller shaft 13 in the left-right direction, and covers substantially the center in the left-right direction of the supply roller shaft 13. Further, the rear upper end portion of the supply roller main body 14 is in pressure contact with the front lower end portion of the developing roller main body 12 of the developing roller 4. The diameter of the supply roller body 14 is smaller than the diameter of the developing roller body 12.

  The supply roller 5 is configured to rotate around a supply roller center axis A3 that is the center of the supply roller shaft 13. The supply roller central axis A3 is an example of a second axis.

  The layer thickness regulating blade 6 is disposed in front of the developing roller 4 in the developing chamber 8. More specifically, the layer thickness regulating blade 6 is disposed in front of and above the developing roller central axis A2. The layer thickness regulating blade 6 includes a first clamping member 60 as an example of a support member, a second clamping member 61 as an example of a support member, and a blade member 62.

  The first clamping member 60 has a bent plate shape that is substantially L-shaped in cross-section and that is long in the left-right direction. Specifically, the first clamping member 60 includes a horizontal portion 60A that extends in the front-rear direction and a vertical portion 60B that bends downward from the rear end of the horizontal portion 60A. That is, the vertical portion 60B of the first clamping member 60 extends in the up-down direction in a side view.

  The second clamping member 61 is disposed above the first clamping member 60. The second holding member 61 has a bent plate shape that is substantially L-shaped in cross-section and that is long in the left-right direction. Specifically, the second clamping member 61 extends in the front-rear direction above the first clamping member 60 and is bent downward at the rear end portion thereof so as to face the rear end portion of the first clamping member 60 from the rear. Note that the rear end portion of the second clamping member 61 is inclined to the vertical portion 60B side, that is, the front side as it goes downward to clamp the blade member 62.

  The blade member 62 has a substantially plate shape that is substantially rectangular in a front view that is long in the left-right direction. The blade member 62 extends in the vertical direction in a side view. In other words, the extending direction of the blade member 62 is the vertical direction. The upper end portion of the blade member 62 is supported so as to be sandwiched between the vertical portion 60 </ b> B of the first sandwiching member 60 and the rear end portion of the first sandwiching member 60. The lower end portion of the blade member 62 is in contact with the front upper end portion of the developing roller 4.

The toner storage chamber 7 and the developing chamber 8 are tangent lines on the front side of the supply roller body 14 of the supply roller 5, and are defined by a boundary line B along the extending direction of the layer thickness regulating blade 6, that is, the vertical direction. Yes.
2. Overall Configuration of Printer Such a developing cartridge 1 is installed in a printer 15 as shown in FIG.

  The printer 15 is an electrophotographic monochrome printer. The printer 15 includes a main body casing 16, a process cartridge 17, a scanner unit 18, and a fixing unit 19.

  The main body casing 16 has a substantially box shape. The main body casing 16 includes an opening 20, a front cover 21, a paper feed tray 22, and a paper discharge tray 23.

  The opening 20 is configured to penetrate the front wall of the main casing 16 in the front-rear direction and allow the process cartridge 17 to pass therethrough.

  The front cover 21 is configured to open or close the opening 20.

  The paper feed tray 22 is disposed at the bottom of the main casing 16. The paper feed tray 22 is configured to accommodate the paper P.

  The paper discharge tray 23 is disposed on the upper surface of the main casing 16.

  The process cartridge 17 is configured to be attached to or detached from the main body casing 16 through the opening 20. The process cartridge 17 includes a drum cartridge 24 as an example of a photosensitive cartridge and the developing cartridge 1 described above.

  The drum cartridge 24 includes a photosensitive drum 25 as an example of a photosensitive member, a scorotron charger 26, and a transfer roller 27.

  The photosensitive drum 25 is disposed at the rear end portion of the drum cartridge 24 and has a substantially cylindrical shape extending in the left-right direction. The photosensitive drum 25 is rotatably supported by the frame of the drum cartridge 24.

  The scorotron charger 26 is disposed behind the photosensitive drum 25 and spaced from the photosensitive drum 25.

  The transfer roller 27 is disposed below the photosensitive drum 25. The transfer roller 27 is in contact with the lower end portion of the photosensitive drum 25.

  The developing cartridge 1 is configured to be attached to or detached from the drum cartridge 24. Further, the rear end portion of the developing roller 4 contacts the front end portion of the photosensitive drum 25 in a state where the developing cartridge 1 is mounted on the drum cartridge 24.

  The scanner unit 18 is disposed above the process cartridge 17. The scanner unit 18 is configured to emit a laser beam based on image data toward the photosensitive drum 25 as indicated by a dotted line in FIG.

  The fixing unit 19 is disposed behind the process cartridge 17. The fixing unit 19 includes a heating roller 28 and a pressure roller 29. The pressure roller 29 is disposed rearward and downward with respect to the heating roller 28 and is in pressure contact with the rear lower end portion of the heating roller 28.

  When the printer 15 starts an image forming operation under the control of a control unit (not shown), the scorotron charger 26 uniformly charges the surface of the photosensitive drum 25. Thereafter, the scanner unit 18 exposes the surface of the photosensitive drum 25. Thereby, an electrostatic latent image based on the image data is formed on the surface of the photosensitive drum 25.

  The supply roller 5 supplies the toner in the development frame 2 to the development roller 4. As a result, the toner is frictionally charged positively between the developing roller 4 and the supply roller 5 and is carried on the developing roller 4. The layer thickness regulating blade 6 regulates the toner carried on the developing roller 4 to a certain thickness.

  The developing roller 4 supplies toner regulated to a certain thickness to the electrostatic latent image on the surface of the photosensitive drum 25. As a result, the toner image is carried on the surface of the photosensitive drum 25.

  The paper P is fed from the paper feed tray 22 between the photosensitive drum 25 and the transfer roller 27 one by one at a predetermined timing by the rotation of various rollers. The toner image on the photosensitive drum 25 is transferred to the paper P when passing between the photosensitive drum 25 and the transfer roller 27.

Thereafter, the heating roller 28 and the pressure roller 29 heat and press the paper P passing between them. As a result, the toner image on the paper P is thermally fixed on the paper P. Thereafter, the paper P is discharged to the paper discharge tray 23.
3. Details of Developing Cartridge As shown in FIGS. 3A and 4, the developing cartridge 1 includes the developing frame 2 and a drive unit 31 described above.
(1) Development Frame The development frame 2 includes a left wall 32 as an example of a first wall, a right wall 33 as an example of a second wall, a front wall 34, a lower wall 35, and an upper wall 36. ing.

  The left wall 32 is disposed at the left end portion of the developing frame 2. The left wall 32 has a substantially plate shape that is substantially rectangular in a side view extending in the front-rear direction. As shown in FIGS. 3B and 5, the left wall 32 includes a first screwing portion 38, a second screwing portion 39, a third screwing portion 40, a hooking portion 41, a caulking portion 37, A frame protrusion 42 is provided.

  The first screwing portion 38 is disposed at the rear upper end portion of the left wall 32. The first threaded portion 38 has a substantially cylindrical shape that protrudes leftward from the left surface of the left wall 32. The first screwing portion 38 has a first screw hole 38A and a first engaging portion 38B.

  The first screw hole 38A has a substantially circular shape when viewed from the side, and is recessed from the left end surface of the first screwing portion 38 to the right.

  The first engaging portion 38 </ b> B is disposed at the left end portion of the first screwing portion 38. The first engaging portion 38B has a substantially cylindrical shape extending leftward from the peripheral edge portion of the first screw hole 38A.

  The second threaded portion 39 is disposed at the lower end at the approximate center of the left wall 32 in the front-rear direction. The second threaded portion 39 has a substantially cylindrical shape that protrudes leftward from the left surface of the left wall 32. The second screwing part 39 has a second screw hole 39A and a second engaging part 39B.

  The second screw hole 39 </ b> A has a substantially circular shape in a side view, and is recessed rightward from the left end surface of the second screwing portion 39.

  The second engaging portion 39 </ b> B is disposed at the left end portion of the second screwing portion 39. The second engaging portion 39B has a substantially cylindrical shape extending leftward from the peripheral edge portion of the second screw hole 39A.

  The 3rd screwing part 40 is arrange | positioned at the front upper end part of the left wall 32, as shown to FIG. 3B. The third threaded portion 40 has a substantially cylindrical shape that protrudes leftward from the left surface of the left wall 32. The third screwing portion 40 has a third screw hole 40A and a third engagement portion 40B.

  The third screw hole 40 </ b> A has a substantially circular shape when viewed from the side, and is recessed rightward from the left end surface of the third screwing portion 40.

  The third engaging portion 40B is disposed at the left end portion of the third screwing portion 40. The third engaging portion 40B has a substantially cylindrical shape extending leftward from the peripheral edge portion of the third screw hole 40A.

  The caulking portion 37 is disposed at the rear lower end portion of the left wall 32 as shown in FIGS. 3B and 5. The caulking portion 37 has a substantially cylindrical shape that protrudes leftward from the left surface of the left wall 32.

  The hook portion 41 is disposed at a substantially central position in the front-rear direction of the left wall 32 and at the front lower side of the second screwing portion 39. The hook portion 41 has a substantially plate shape that is substantially U-shaped when viewed from the bottom.

  The frame protrusion 42 is disposed between the caulking portion 37 and the second screwing portion 39 on the left wall 32. The frame protrusion 42 has a plate shape that protrudes downward from the lower end edge of the left wall 32 in a substantially rectangular shape in side view. The frame projecting portion 42 constitutes an engaging projecting portion 64 as an example of the projecting portion together with a bearing projecting portion 49 described later.

  The right wall 33 is disposed at the right end of the developing frame 2 as shown in FIGS. 1 and 7. Similar to the left wall 32, the right wall 33 has a substantially plate shape that is substantially rectangular in a side view extending in the front-rear direction.

  The front wall 34 is constructed between the front end portion of the left wall 32 and the front end portion of the right wall 33. The front wall 34 has a substantially plate shape extending in the left-right direction.

  As shown in FIGS. 1 and 4, the lower wall 35 is constructed between the lower end portion of the left wall 32 and the lower end portion of the right wall 33. The lower wall 35 has a substantially plate shape extending from the lower end portion of the front wall 34 while being curved backward. The lower wall 35 includes a curved wall 43 and a bent wall 44.

  The curved wall 43 extends continuously from the lower end portion of the front wall 34 toward the rear from the center of the lower wall 35 to the front portion. The curved wall 43 has a substantially arc shape in a side sectional view along the rotation locus of the agitator 3.

  The bent wall 44 has a substantially W-shaped side sectional view extending in the rear direction continuously from the rear end portion of the curved wall 43 in the rear portion of the lower wall 35. The front portion of the bent wall 44 has a substantially arc shape along the rotation locus of the supply roller 5. A rear portion of the bent wall 44 extends rearward.

  As shown in FIGS. 1 and 7, the upper wall 36 is disposed above the upper end of the left wall 32, the upper end of the right wall 33, and the upper end of the front wall 34. The upper wall 36 has a substantially plate shape extending in the left-right direction. The upper wall 36 includes a blade support wall 45.

  The blade support wall 45 is configured to support the layer thickness regulating blade 6. The blade support wall 45 is disposed at the rear end portion of the upper wall 36. The blade support wall 45 has a substantially rectangular plate shape in plan view extending in the left-right direction. The rear surface of the blade support wall 45 extends in the vertical direction in a side view. That is, the rear surface of the blade support wall 45 extends in the same direction as the layer thickness regulating blade 6.

The upper wall 36 is fixed to the upper end portion of the left wall 32, the upper end portion of the right wall 33, and the upper end portion of the front wall 34 by a method such as welding at a peripheral portion other than the blade support wall 45.
(2) Detailed Arrangement of Developing Roller, Supply Roller, Layer Thickness Regulating Blade, and Agitator Next, FIG. 1 shows the detailed arrangement of the agitator 3, the developing roller 4, the supply roller 5, and the layer thickness regulating blade 6. It explains using.

  As described above, the agitator 3 is disposed at a substantially central portion in the front-rear and up-down directions of the toner storage chamber 7, the developing roller 4 is disposed at the rear end of the developing chamber 8, and the supply roller 5 is developed. In the chamber 8, the layer thickness regulating blade 6 is disposed in front of and above the developing roller 4 in the developing chamber 8.

  Then, a first dividing line D1 as an example of an imaginary line passing through the supply roller central axis A3 along the vertical direction, and a second dividing line D2 passing through the developing roller central axis A2 and the agitator central axis A1 are assumed. In other words, the second partition line D2 is along the direction in which the vertical portion 60B of the first clamping member 60 that contacts the blade member 62 extends.

  The front upper area defined by the first lane marking D1 and the second lane marking D2 is the first quadrant T1 as an example of the first area, the front lower area is the second quadrant T2, and the rear lower area is the first quadrant T2. The third quadrant T3 as an example of the two areas is referred to as a fourth quadrant T4.

  Further, in a side view, a point on a straight line (not shown) connecting the developing roller central axis A2 and the supply roller central axis A3 and intersecting with the peripheral surface of the developing roller main body 12 of the developing roller 4 and the developing roller main body 12 A nip point N with the supply roller body 14 is set. The developing roller central axis A 2, the first imaginary line V 1 passing through the contact C between the developing roller body 12 of the developing roller 4 and the layer thickness regulating blade 6, and the tangent line of the developing roller body 12 of the developing roller 4 The second virtual line V2 passing through the nip point N is assumed.

  At this time, the agitator 3, the developing roller 4, the supply roller 5, and the layer thickness regulating blade 6 are arranged so that the first imaginary line V1 and the second imaginary line V2 intersect in the first quadrant T1. Supported by the developing frame 2.

Further, the layer thickness regulating blade 6 is disposed so as to be sandwiched between the developing roller 4 and the blade support wall 45 of the developing frame 2.
(3) Drive Unit As shown in FIGS. 3B and 5, the drive unit 31 includes a bearing member 46, a gear train 47, and a gear cover 48 as an example of a cover member.
(3-1) Bearing Member The bearing member 46 has a substantially rectangular plate shape in side view, and is attached to the left surface of the left side wall 34. The bearing member 46 rotatably supports the left end portion of the supply roller shaft 13 and rotatably supports the left end portion of the developing roller shaft 11. That is, the left end portions of the supply roller shaft 13 and the developing roller shaft 11 are supported by the left wall 34 via the bearing member 46 so as to be relatively rotatable. Each of the left end portion of the supply roller shaft 13 and the left end portion of the developing roller shaft 11 protrudes leftward from the bearing member 46. The bearing member 46 includes a bearing protrusion 49.

The bearing protrusion 49 has a plate shape that protrudes downward from the lower end edge of the bearing member 46 in a substantially rectangular shape in side view. When projected in the left-right direction, the bearing projection 49 matches the frame projection 42 of the left wall 32 with its outer shape. The right surface of the bearing protrusion 49 is in contact with the left surface of the frame protrusion 42. Thus, the bearing protrusion 49 and the frame protrusion 42 described above are configured as an engagement protrusion 64 as an example of a protrusion protruding downward from the developing cartridge 1.
(3-2) Gear Train The gear train 47 is disposed on the left side of the left wall 32. The gear train 47 includes a development coupling 50 as an example of a coupling member, a development gear 51 as an example of a first gear, a supply gear 52 as an example of a supply gear and a second gear, an idle gear 53, An agitator gear 54 and a detection gear 55 are provided.
(3-2-1) Development Coupling The development coupling 50 is disposed in the rear part of the left surface of the left wall 32. The developing coupling 50 is configured to transmit a driving force input from a driving source (not shown) to the agitator 3, the developing roller 4, and the supply roller 5. The developing coupling 50 is supported so as to be rotatable about a shaft portion (not shown). The rotation center of the development coupling 50 is defined as a coupling center axis A4. The coupling center axis A4 is an example of a third axis. A shaft portion (not shown) extends in the left-right direction and is fixed to the left wall 32 so as not to be relatively rotatable. The development coupling 50 has a substantially cylindrical shape extending in the left-right direction. The development coupling 50 is integrally provided with a coupling gear portion 56 as an example of a third gear and a coupling portion 57.

  The coupling gear portion 56 is a right portion of the developing coupling 50 and has gear teeth over the entire peripheral surface thereof.

  The coupling portion 57 is a left portion of the development coupling 50 and has a substantially cylindrical shape whose central axis coincides with the coupling gear portion 56. Further, the outer diameter of the coupling portion 57 is smaller than the outer diameter of the coupling gear portion 56. The coupling part 57 has a recess 58 and a pair of protrusions 59.

  The concave portion 58 is recessed in a substantially circular shape in a side view from the left end surface of the coupling portion 57 to the right.

  Each of the pair of protrusions 59 protrudes radially inward from the radially inner peripheral surface of the recess 58. Each of the pair of protrusions 59 is disposed to face each other in the radial direction of the recess 58. Each of the pair of protrusions 59 has a substantially prismatic shape extending in the left-right direction.

As shown in FIGS. 3A and 3B, when the third imaginary line V3 passing through the coupling center axis A4 along the vertical direction is imagined, the supply roller shaft 13 is arranged behind the third imaginary line V3. Has been.
(3-2-2) Developing Gear As shown in FIGS. 3B and 5, the developing gear 51 transmits a driving force input from a driving source (not shown) to the developing roller 4 via the developing coupling 50. It is configured. The development gear 51 is disposed behind the development coupling 50. The developing gear 51 has a substantially cylindrical shape extending in the left-right direction, and has gear teeth over the entire peripheral surface thereof. The developing gear 51 is attached to the left end portion of the developing roller shaft 11 so as not to be relatively rotatable. Further, the front end portion of the developing gear 51 meshes with the right portion of the rear end portion of the coupling gear portion 56 of the developing coupling 50.
(3-2-3) Supply Gear The supply gear 52 is configured to transmit a driving force input from a driving source (not shown) to the supply roller 5 via the development coupling 50. The supply gear 52 is disposed below the developing coupling 50 and adjacent to the left side of the bearing protrusion 49 of the bearing member 46 described above. The supply gear 52 has a substantially cylindrical shape extending in the left-right direction, and has gear teeth over the entire peripheral surface thereof. The supply gear 52 is attached to the left end portion of the supply roller shaft 13 so as not to be relatively rotatable. Further, the front upper end portion of the supply gear 52 meshes with the substantially central portion in the left-right direction at the rear lower end portion of the coupling gear portion 56. That is, as shown in FIG. 6, the supply gear 52 meshes with the coupling gear portion 56 so as to be displaced from the developing gear 51 in the left-right direction.
(3-2-4) Idle Gear The idle gear 53 is disposed in front of the development coupling 50 as shown in FIGS. 3B and 5. The idle gear 53 is supported so as to be rotatable around a shaft portion (not shown). A shaft portion (not shown) extends in the left-right direction and is fixed to the left wall 32 so as not to be relatively rotatable. The idle gear 53 is integrally provided with an idle large-diameter gear 53A, an idle medium-diameter portion 53B, and an idle small-diameter gear 53C.

  The idle large-diameter gear 53A is a left portion of the idle gear 53 and has a substantially annular shape having a thickness in the left-right direction. The idle large-diameter gear 53A has gear teeth over the entire peripheral surface thereof. The rear end portion of the idle large diameter gear 53 </ b> A meshes with the front end portion of the coupling gear portion 56 of the developing coupling 50.

  The idle medium diameter portion 53B is a substantially central portion in the left-right direction of the idle gear 53 and protrudes rightward from the right surface of the idle large diameter gear 53A. The idle medium diameter portion 53B has a substantially cylindrical shape with the right end portion closed. The outer diameter of the idle middle diameter portion 53B is smaller than the outer diameter of the idle large diameter gear 53A. The inner diameter of the idle medium diameter portion 53B is substantially the same as the inner diameter of the idle large diameter gear 53A.

  The idle small diameter gear 53C is a right portion of the idle gear 53 and has a substantially cylindrical shape extending rightward from the right surface of the idle medium diameter portion 53B. The outer diameter of the idle small diameter gear 53C is smaller than the inner diameter of the idle medium diameter portion 53B. The inner diameter of the idle small-diameter gear 53C is slightly larger than the outer diameter of a shaft portion (not shown) of the left wall 32. The idle small-diameter gear 53C has gear teeth over the entire peripheral surface thereof.

In the idle gear 53, the central axes of the idle large-diameter gear 53A, the idle medium-diameter portion 53B, and the idle small-diameter gear 53C coincide.
(3-2-5) Agitator Gear The agitator gear 54 is disposed on the front lower side of the idle gear 53. The agitator gear 54 is fixed to the left end portion of the agitator shaft 9 so as not to be relatively rotatable. The agitator gear 54 is integrally provided with an agitator large-diameter gear 54A and an agitator small-diameter gear 54B.

  The agitator large-diameter gear 54A is a right portion of the agitator gear 54 and has a substantially annular shape having a thickness in the left-right direction. The agitator large-diameter gear 54A has gear teeth over the entire peripheral surface thereof. The rear upper end portion of the agitator large diameter gear 54A meshes with the front lower end portion of the idle small diameter gear 53C.

The agitator small diameter gear 54B is a left portion of the agitator gear 54 and has a substantially cylindrical shape whose central axis coincides with the agitator large diameter gear 54A. The outer diameter of the agitator small diameter gear 54B is smaller than the outer diameter of the agitator large diameter gear 54A. The inner diameter of the agitator small diameter gear 54B is substantially the same as the inner diameter of the agitator large diameter gear 54A. The agitator small-diameter gear 54B has gear teeth over the entire peripheral surface thereof.
(3-2-6) Detection Gear The detection gear 55 is disposed in front of the agitator gear 54. The detection gear 55 is supported so as to be rotatable around a shaft portion (not shown). A shaft portion (not shown) extends in the left-right direction from a cap for closing a toner filling port (not shown) of the left wall 32. The detection gear 55 has a substantially cylindrical shape extending in the left-right direction and closed at the left end. The detection gear 55 has gear teeth over half of its peripheral surface. That is, the detection gear 55 is a chipped gear. Further, the rear end portion of the detection gear 55 is configured to mesh with the front end portion of the agitator small diameter gear 54B of the agitator gear 54. The detection gear 55 includes a contact portion 63.

The contact portion 63 protrudes leftward from the left end surface of the detection gear 55 and extends over a range of approximately 60 ° in the circumferential direction of the detection gear 55. The contact part 63 has a substantially plate shape that is curved.
(3-3) Gear Cover The gear cover 48 is assembled to the left wall 32 so as to cover the gear train 47 collectively. As shown in FIGS. 3A and 5, the gear cover 48 includes a rear cover 66 and a front cover 67 as a unit.
(3-3-1) Rear Cover The rear cover 66 is a rear portion of the gear cover 48 and includes a first portion 68 and a second portion 69 as an integral unit.

  The first portion 68 is an upper portion of the rear cover 66 and integrally includes a first base plate 70 and a first peripheral wall 71 protruding rightward from the peripheral edge of the first base plate 70. That is, the first portion 68 has a substantially box shape in which the right end is open and the left end is closed. The first portion 68 includes a coupling covering portion 72, a developing roller covering portion 73, and a first fixing portion 74.

  The coupling covering portion 72 is partitioned at the approximate center of the first base plate 70 in the up-down and front-back directions. The coupling covering portion 72 includes a drive input opening 75 and a cylindrical portion 76.

  The drive input opening 75 passes through the first base plate 70 in a substantially circular shape when viewed from the side.

  The cylindrical portion 76 has a substantially cylindrical shape extending leftward from the left surface of the first base plate 70 at the peripheral edge of the drive input opening 75. The inner diameter of the cylindrical portion 76 is substantially the same as the diameter of the drive input opening 75. Further, the horizontal dimension of the cylindrical portion 76 is substantially the same as the horizontal dimension of the coupling portion 57 of the developing coupling 50.

  The developing roller covering portion 73 is defined behind the coupling covering portion 72 and at a rear end portion at a substantially center in the vertical direction of the first base plate 70. The developing roller covering portion 73 includes a color portion 77.

  The collar portion 77 has a substantially cylindrical shape extending in the left-right direction and closed at the left end. The inner diameter of the collar portion 77 is slightly larger than the outer diameter of the developing roller shaft 11.

  The first fixing portion 74 is defined above the developing roller covering portion 73 and at the rear upper end portion of the first base plate 70. The first fixing portion 74 is slightly recessed to the right than the developing roller covering portion 73. The first fixing portion 74 includes a first insertion hole 78.

  The first insertion hole 78 passes through the first base plate 70 in a substantially circular shape when viewed from the side. The inner diameter of the first insertion hole 78 is slightly larger than the first engagement portion 38 </ b> B of the first screwing portion 38.

  The second portion 69 is a lower portion of the rear cover 66, and is disposed below the first portion 68 so as to continue from the right end portion of the lower first peripheral wall 71. That is, the second portion 69 is disposed on the right side of the first base plate 70 of the first portion 68. The second portion 69 is integrally provided with a second base plate 79 and a second peripheral wall 80 as an example of a second covering portion protruding from the peripheral edge of the second base plate 79. That is, the second portion 69 has a substantially box shape in which the right end is open and the left end is closed. The second portion 69 includes a supply roller covering portion 81, a locking portion 83, and a notch portion 84 as an example of an opening.

  The supply roller covering portion 81 is defined below the coupling covering portion 72 and substantially at the center in the front-rear direction of the second base plate 79. The supply roller covering portion 81 includes a semicircular portion 82.

  The semicircular portion 82 has a substantially semicircular shape in side view protruding downward from the supply roller covering portion 81. The arc radius of the semicircular portion 82 is slightly larger than the radius of the supply gear 52.

  The supply roller covering portion 81 has a semicircular portion 82 projecting downward from the supply gear 52 when projected in the left-right direction in a state where the gear cover 48 is assembled to the left wall 32.

  Thereby, the supply roller coating | coated part 81 has coat | covered all the left surfaces of the supply gear 52 from the left. The supply roller covering portion 81 is configured as an example of a first covering portion that covers the supply gear 52 and the developing gear 51 from the left together with the developing roller covering portion 73.

  The locking portion 83 is defined below the developing roller covering portion 73 and behind the supply roller covering portion 81 and at the rear end portion of the second base plate 79. The locking part 83 has a substantially bottomed frame shape whose right end is closed. The locking portion 83 includes a locking insertion hole (not shown) that penetrates the right end portion of the locking portion 83 in a substantially circular shape when viewed from the side.

  The locking portion 83 includes a protective wall 85.

  The protective wall 85 has a substantially plate shape that is substantially L-shaped in side view and protrudes leftward from the lower right end and the right front end of the locking portion 83.

As shown in FIGS. 5 and 6, the notch portion 84 is a lower portion of the supply roller covering portion 81, and a substantially central portion in the front-rear direction in the lower portion of the second peripheral wall 80 is notched. In other words, the notch portion 84 is partitioned as a space below the supply roller covering portion 81 and in front of the locking portion 83.
(3-3-2) Front Cover As shown in FIGS. 3A and 5, the front cover 67 continuously extends forward from the front end portion of the rear cover 66 and constitutes a front portion of the gear cover 48. Yes. The front cover 67 includes a third portion 86, a fourth portion 87, and a fifth portion 88 as a single unit.

  The third portion 86 is a rear upper portion of the front cover 67 and integrally includes a third base plate 89 and a third peripheral wall 90 protruding rightward from the peripheral end edge of the third base plate 89. That is, the third portion 86 has a substantially box shape in which the right end is open and the left end is closed. Although not shown, the third portion 86 includes an idle gear support portion that is inserted into the idle gear 53 and supports the idle gear 53 in a state where the gear cover 48 is assembled to the left wall 32.

  The fourth portion 87 is a rear lower portion of the front cover 67 and is disposed below the third portion 86 so as to be continuous from the right end portion of the lower third peripheral wall 90. That is, the fourth portion 87 is disposed on the right side of the third base plate 89 of the third portion 86. The fourth portion 87 includes a fourth base plate 91 and a fourth peripheral wall 92 that projects rightward from the lower end edge of the fourth base plate 91. That is, the fourth portion 87 has a substantially plate shape that is substantially L-shaped when viewed from the front section. The fourth portion 87 includes a second fixing portion 93 and a locking claw 94.

  The second fixing portion 93 is partitioned at the rear end portion of the fourth base plate 91. The second fixing portion 93 includes a second insertion hole (not shown) that penetrates the second fixing portion 93 in a substantially circular shape when viewed from the side. The inner diameter of the second insertion hole (not shown) is slightly larger than the outer diameter of the second engaging portion 39B of the second screwing portion 39.

  The locking claw 94 has a substantially saddle shape that protrudes rightward from the right end portion of the fourth circumferential wall 92 at the approximately center in the front-rear direction and is bent upward at the right end portion.

  The fifth portion 88 is a front portion of the front cover 67 and protrudes leftward continuously from the front end edges of the third portion 86 and the fourth portion 87. The fifth portion 88 includes a detection gear covering portion 95 and a third fixing portion 96.

  The detection gear covering portion 95 has a substantially cylindrical shape that is continuous from the front end edges of the third portion 86 and the fourth portion 87, protrudes toward the left, and is closed at the left end. That is, the left end portion of the detection gear covering portion 95 is located to the left of the third portion 86 and the fourth portion 87. The detection gear covering portion 95 includes a contact portion opening 97 and a detection gear restricting portion 98.

  The contact portion opening 97 penetrates the left end wall of the detection gear covering portion 95 in a substantially C shape in a side view with its lower end opened so that the contact portion 63 of the detection gear 55 can protrude.

  The detection gear restricting portion 98 has a substantially cylindrical shape that protrudes rightward from the center of the right surface of the right wall of the detection gear covering portion 95. The outer diameter of the detection gear restricting portion 98 is slightly smaller than the inner diameter of the detection gear 55.

As shown in FIG. 3A, the third fixing portion 96 protrudes forward from the upper right end portion in front of the detection gear covering portion 95. The third fixing portion 96 has a substantially box shape in which the right end portion is opened and the left end portion is closed. Note that the left end wall of the third fixing portion 96 is located to the right of the third base plate 89 and is substantially flush with the fourth base plate 91. The third fixing portion 96 includes a third insertion hole (not shown) that penetrates the third fixing portion 96 in a substantially circular shape when viewed from the side. The inner diameter of the third insertion hole (not shown) is slightly larger than the outer diameter of the third engagement portion 40B of the third screwing portion 40.
4). Attaching / detaching the gear cover to / from the developing frame Such a gear cover 48 is assembled to the developing frame 2 by an operator.

  In order to assemble the gear cover 48 to the developing frame 2, as shown in FIGS. 4 and 5, first, the gear cover 48 is assembled from the left to the left wall 32 to which the gear train 47 is assembled. More specifically, in the rear cover 66, the collar portion 77 receives the developing roller shaft 11 and the cylindrical portion 76 receives the coupling portion 57. Further, in the front cover 67, an idle gear support portion (not shown) is inserted into the agitator gear 54, the detection gear restricting portion 98 is inserted into the detection gear 55, and the contact portion opening 97 is in contact with the detection gear 55. Accept part 63.

  Then, in the rear cover 66, the first insertion hole 78 receives the first engagement portion 38B of the first screwing portion 38, and the locking insertion hole (not shown) of the locking portion 83 receives the caulking portion 37. Further, in the front cover 67, a second insertion hole (not shown) receives the second engagement part 39B of the second screwing part 39, and a third insertion hole (not shown) is the third engagement of the third screwing part 40. The portion 40B is received and locked so that the locking claw 94 is hooked with respect to the catching portion 41.

  In this way, the gear cover 48 is assembled to the left wall 32 from the left side.

  Thereby, the left end surface of the supply gear 52 and the right surface of the supply roller covering portion 81 face each other with a space therebetween. In addition, the third base plate 89 covers the idle gear 53 and the agitator gear 54, the detection gear cover 95 covers the detection gear 55, and the idle gear 53 and the detection gear 55 have their rotation shaft centers respectively. It is supported on the left wall 32 in a rotatable manner without shifting.

  Next, the first screw member 101 is screwed into the first screw hole 38A via the first insertion hole 78, and the second screw member 102 is inserted through the second insertion hole (not shown) of the second fixing portion 93. The third screw member 103 is screwed into the third screw hole 40 </ b> A via a third insertion hole (not shown) of the third fixing portion 96.

  As described above, in the gear cover 48, the rear cover 66 covers the development coupling 50, the development gear 51, and the supply gear 52, and the front cover 67 covers the agitator gear 54 and the detection gear 55. Thus, it is assembled to the left wall 32.

  As shown in FIGS. 4 and 6, the lower end portion of the supply gear 52 is exposed from the notch portion 84 of the supply roller covering portion 81 and protrudes downward from the notch portion 84 as viewed from below. .

  Thus, the assembly of the developing cartridge 1 is completed.

  Further, in order to remove the gear cover 48 from the left wall 32, the gear cover 48 is removed by a procedure reverse to the procedure described above.

  Specifically, first, the first screw member 101 is removed from the first screw hole 38A, the second screw member 102 is removed from the second screw hole 39A, and the third screw member 103 is removed from the third screw hole 40A. It is.

  The gear cover 48 is removed from the left wall 32 by releasing the locking claw 94 from the hook 41 and moving the gear cover 48 to the left.

Thus, the removal of the gear cover 48 from the left wall 32 is completed.
5. Details of Process Cartridge The process cartridge 17 is configured by mounting the above-described developing cartridge 1 on the drum cartridge 24.

  As shown in FIGS. 7 and 8, the drum cartridge 24 includes a drum frame 105, the photosensitive drum 25, and the scorotron charger 26 described above.

  The drum frame 105 has a substantially rectangular bottomed frame shape whose lower end is closed. The drum frame 105 has a rear portion defined as a drum housing portion 106 and a front portion defined as a developing cartridge mounting portion 107 as an example of a cartridge mounting portion.

  The drum housing portion 106 supports the photosensitive drum 25 and the scorotron charger 26.

  The developing cartridge mounting portion 107 is configured so that the developing cartridge 1 can be mounted or removed. The developing cartridge mounting unit 107 includes a drum bottom wall 108 as an example of a bottom wall.

  The drum bottom wall 108 is a lower end portion of the developing cartridge mounting portion 107 and has a substantially plate shape extending in the front-rear and left-right directions. The drum bottom wall 108 includes an engagement hole 109.

  The engagement hole 109 passes through the rear left end portion of the drum bottom wall 108 in a substantially rectangular shape in a plan view that is long in the front-rear direction. The front-rear dimension of the engagement hole 109 is slightly longer than the front-rear dimension of the engagement protrusion 64 of the developing cartridge 1, and the left-right dimension of the engagement hole 109 is larger than the left-right dimension of the engagement protrusion 64. Slightly longer.

  When the developing cartridge 1 is attached to the developing cartridge attaching portion 107 of the drum frame 105, the rear end portion of the developing roller 4 of the developing cartridge 1 is connected to the front end portion of the photosensitive drum 25 as shown in FIG. 9, the lower wall 35 of the developing frame 2 of the developing cartridge 1 faces the drum bottom wall 108 of the drum frame 105 as shown in FIG. 9. At this time, the engagement protrusion 64 is assembled so as to be inserted from above into the engagement hole 109 of the drum bottom wall 108. Further, the left rear end portion of the drum bottom wall 108 is disposed below the supply gear 52 so as to face the supply gear 52 in the upward direction and cover the supply gear 52.

In this way, the process cartridge 17 is configured.
6). Effect (1) According to the developing cartridge 1, as shown in FIGS. 4 and 6, the developing gear 51 and the supply are provided by the developing roller covering portion 73, the supply roller covering portion 81 and the second peripheral wall 80 of the gear cover 48. While covering both of the gears 52, the supply gear 52 protrudes from the notch 84 of the second peripheral wall 80 so that the lower end thereof is exposed.

  Therefore, since the second peripheral wall 80 has the cutout portion 84 from which the supply gear 52 projects, the gear cover 48 can be downsized in the vertical direction.

As a result, the developing cartridge 1 can be downsized while both the developing gear 51 and the supply gear 52 can be protected by the gear cover 48.
(2) Further, according to the developing cartridge 1, the lower end portion of the supply gear 52 protrudes from the second peripheral wall 80, as shown in FIG. It is covered with a supply roller covering portion 81.

Therefore, it is possible to reliably protect the entire left surface of the supply gear 52 while reducing the size of the developing cartridge 1.
(3) Further, according to the developing cartridge 1, as shown in FIG. 6, grease can be applied to the supply gear 52 through the notch portion 84 of the second peripheral wall 80.

  Further, since the developing gear 51 and the supply gear 52 are displaced in the left-right direction, the developing gear 51 can be coated with grease through the notch 84 of the second peripheral wall 80.

Therefore, the grease can be efficiently applied to both the developing gear 51 and the supply gear 52 through the notch 84 of the second peripheral wall 80.
(4) Further, according to the developing cartridge 1, as shown in FIG. 3B, the supply roller shaft 13 is disposed on the developing roller 4 side with respect to the third imaginary line V3 when viewed from the left-right direction. The developing gear 51 connected to the roller 4 and the supply gear 52 connected to the supply roller 5 can be disposed so as to be relatively close to each other.

Therefore, the developing roller 4 and the supply roller 5 can be disposed at appropriate positions in the developing cartridge 1, and the developing cartridge 1 can be downsized.
(5) Moreover, according to this developing cartridge 1, as shown in FIG. 3B and FIG. 4, the right surface of the supply gear 52 can be protected by the engaging protrusion 64.

Therefore, even if the lower end portion of the supply gear 52 protrudes from the cutout portion 84 of the second peripheral wall 80, the supply gear 52 can be more reliably protected.
(6) According to the drum cartridge 24, as shown in FIGS. 7 and 9, when the developing cartridge 1 is mounted on the developing cartridge mounting portion 107, the drum bottom wall 108 protrudes from the notch portion 84 and is exposed. The developing cartridge 1 can be easily positioned with respect to the drum cartridge 24 by engaging the engaging protrusion 64 with the engaging hole 109 while protecting the lower end portion of the supply gear 52.

Further, the developing cartridge 1 is enlarged in the direction in which the supply gear 52 protrudes, that is, in the downward direction because the engaging protrusion 64 protrudes from the developing cartridge 1. Since the mating protrusion 64 is inserted into the engagement hole 109, an increase in the size of the process cartridge 17 can be suppressed.
7). Modification The above-described developing cartridge 1 is an embodiment of the developing cartridge of the present invention, and the present invention is not limited to the above-described embodiment.

  For example, in the above-described embodiment, the first virtual line V1 and the second virtual line V2 intersect in the first quadrant T1, but the first virtual line V1 and the second virtual line V2 are in the third quadrant T3. The developing roller 4, the supply roller 5, and the layer thickness regulating blade 6 can be arranged so as to intersect each other.

  In the above-described embodiment, the gear cover 48 includes the rear cover 66 and the front cover 67 as a single unit. However, the rear cover 66 and the front cover 67 may be separated and configured to be separable. .

  Further, in the gear cover 48, the second portion 69 of the rear cover 66 is integrally provided with the second base plate 79 and the second peripheral wall 80. However, the second peripheral wall 80 is configured to be separable from the second base plate 79. You can also

  For example, instead of the developing roller 4 described above, a developer carrier such as a brush roller or a magnetic roller can be applied.

  For example, instead of the supply roller 5 described above, a brush-like supply member can be applied.

  In addition to the separation type in which the drum cartridge 24 and the developing cartridge 1 are separated as described above, the process cartridge 17 may be configured as an integrated type that integrally includes the drum cartridge 24 and the developing cartridge 1.

  Furthermore, the developing cartridge 1 can be configured such that a toner cartridge that contains toner is detachably attached to a frame having the developing roller 4.

DESCRIPTION OF SYMBOLS 1 Developing cartridge 2 Developing frame 4 Developing roller 5 Supplying roller 13 Supplying roller shaft 17 Process cartridge 24 Drum cartridge 25 Photosensitive drum 48 Gear cover 51 Developing gear 52 Supplying gear 56 Coupling gear part 64 Engaging protrusion 73 Developing roller covering part 80 Second peripheral wall 81 Supply roller covering portion 84 Notch portion 107 Development cartridge mounting portion 108 Drum bottom wall 109 Engagement hole A2 Development roller center axis A3 Supply roller center axis A4 Coupling center axis V3 Third imaginary line

Claims (6)

A housing configured to contain a developer therein;
A developer carrier configured to rotate about a first axis extending in a first direction;
A supply member configured to rotate about a second axis parallel to the first axis and configured to contact the developer carrier and supply the developer to the developer carrier;
A first gear connected to an end of the developer carrier;
A second gear coupled to an end of the supply member;
A gear cover configured to cover the first gear and the second gear, the first cover portion extending in a direction orthogonal to the first direction, and connected to the first cover portion; A gear cover including a second covering portion extending in the first direction,
The second covering portion includes an opening exposing a part of the second gear,
A part of said 2nd gear protrudes rather than the said 2nd coating | coated part through the said opening, The developing cartridge characterized by the above-mentioned.   2. The developing cartridge according to claim 1, wherein the first covering portion covers the entire end surface of the second gear in the first direction. A third gear meshing with both the first gear and the second gear;
The meshing portion of the third gear and the first gear is shifted along the first direction with respect to the meshing portion of the third gear and the second gear. The developing cartridge according to 1 or 2. The third gear is configured to rotate about a third axis parallel to both the first axis and the second axis;
The supply member includes a rotation shaft,
When viewed from the first direction, when the virtual axis passes through the third axis along the direction in which the second gear protrudes from the second covering portion, the rotation axis is more than the virtual line. The developing cartridge according to claim 3, wherein the developing cartridge is disposed on a developer carrying member side. The housing includes a protruding portion that protrudes in a direction in which the second gear protrudes from the second covering portion when viewed from the first direction,
5. The developing cartridge according to claim 1, wherein the projecting portion is disposed adjacent to the second gear in the first direction. 6. A process cartridge comprising the developing cartridge according to claim 5 and a photosensitive cartridge to which the developing cartridge is detachably mounted,
The photosensitive cartridge is
A photoreceptor configured to rotate about an axis along the first direction;
A cartridge mounting portion on which the developing cartridge is mounted;
The cartridge mounting part is
A bottom portion facing the second gear in a direction in which the second gear protrudes from the second covering portion;
The process cartridge according to claim 1, wherein the bottom portion includes an engagement hole that engages with the protrusion.

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