WO2012095009A1 - Photosensitive drum drive assembly, photosensitive drum and process cartridge - Google Patents

Abstract

The invention provides a photosensitive drum drive assembly (12), a photosensitive drum (20) having the drive assembly (12) and a process cartridge. The drive assembly (12) comprises a gear (121) capable of being tightly matched with one end of the drum body (10), an axial adjusting assembly (122) capable of making reciprocating movement relative to the gear along the axial direction of the gear. The axial adjusting assembly (122) comprises a driving force receiving head (123) capable of being matched with a driving force output head (8), a driving lever (124) and a shift pin (125). One end of the driving lever (124) is inserted into the gear (121) along the axial direction. The driving force receiving head (123) is fixed on the outer end of the driving lever (124) and is located outside the gear. The shift pin (125) is fixed on a portion of the driving lever located in the gear. A blocking part (126) capable of being matched with the shift pin (125) to prevent the driving lever from rotating relative to the gear is arranged in the gear.

Description

 Drum drive unit, drum and process cartridge Technical field

The present invention relates to a photosensitive drum drive assembly and a photosensitive drum and process cartridge having the same. The present application claims priority to Chinese Patent Application No. 201110006998.2, entitled "Drum Drive Module, Photosensitive Drum, and Process Cartridge", which is incorporated herein by reference. In the application.

Background technique

Image forming apparatuses such as laser printers, copying machines, facsimile machines and the like generally use a detachable process cartridge as a container for replenishing toner and cooperating with the medium to form an image. The driving force required to process the moving parts of the cartridge is provided by a motor within the image forming apparatus. There are two main types of driving force transmission between the driving force receiving portion of the process cartridge and the driving force output mechanism of the motor. One is a process cartridge as disclosed in U.S. Patent No. 4,829,335, the photosensitive drum driving assembly of the process cartridge includes A helical gear provided at one end of the photosensitive drum is engaged with a helical gear of the photosensitive drum on the process cartridge through a helical gear of a driving member on the image forming apparatus to drive the photosensitive drum to rotate. The other is a process cartridge as disclosed in Chinese Patent No. CN1217241C, the drive drum drive assembly of the process cartridge includes a non-circular section projection extending from one end of the photosensitive drum, the non-circular section projection and the driving force output on the image forming apparatus The non-circular cross-section engagement holes of the head cooperate to receive and transmit a driving force to rotate the photosensitive drum.

A processing box adopting the above-mentioned second power transmission mode is as shown in FIG. 1 , and is mainly composed of a powder silo 1 containing toner and a waste toner bin 2 accommodating waste powder, and the powder silo 1 has a stirring rack and is sent. Moving parts such as a powder roller and a developing roller, and moving parts in the waste toner box 2 are photosensitive drums, and there are also charging rollers and cleaning blades. The photosensitive drum is an important component of the process cartridge, and includes a drum body made of a conductive material and a pair of drum flanges having a shaft portion on which a gear is provided for transmitting a drive to other moving parts in the process cartridge. force. The photosensitive drum is rotatably supported between the two side walls 4 of the waste toner box 2 through the above two drum flanges. One of the drum flanges serves as a photosensitive drum drive unit projecting from a circular hole of a side wall 4, and a circular hole flange 41 is formed around the circular hole, and the inner surface 42 of the circular hole rotatably supports the photosensitive drum drive unit. A twisted columnar projection 3 having a triangular cross section is provided on the front end surface of the shaft portion of the photosensitive drum drive unit. Further, the non-circular cross-sectional projection of the photosensitive drum drive assembly may also take the form of a non-twisted cylindrical projection 9 as shown in FIG. In Fig. 2, the motor 5, the gear 6, the gear 7, and the driving force output head 8 in the image forming apparatus are indicated by two-dot chain lines. When the photosensitive drum (process cartridge) is loaded into the image forming apparatus, the driving force output head 8 will be shifted to the left in the axial direction of the gear 7, and the recessed hole having the same cross section as the projection 9 covers the projection 9, and is convex A side surface 92 of the corner portion 91 of the nine contacts, thereby completing the torque transmission of the motor 5 to the photosensitive drum (process cartridge).

Figure 1 shows the intertwined twisted holes cooperating with the twisted projections. Figure 2 shows the mutually engageable straight recesses that cooperate with the upright projections. In the transmission mode shown in FIG. 2, the driving force from the driving force output head 8 is transmitted to the drum body through the projection 9 of the photosensitive drum driving assembly, the shaft portion having the outer circumferential surface 93, and the gear portion 94; When the process cartridge is loaded into the image forming apparatus and the printing process is started, the axis 81 of the driving force output head 8 and the axis 95 of the photosensitive drum drive unit do not completely coincide with each other due to unstable factors such as vibration of the image forming apparatus and the internal environment of the process cartridge. At the time of printing, the driving force output head 8 drives the photosensitive drum driving assembly to rotate about the axis 81 of the driving force output head 8, and the shaft portion of the photosensitive drum driving assembly rotates around the axis 81 of the driving force output head 8 instead of the axis 95 of the photosensitive drum driving assembly. Then, the rotation diameter of the shaft portion of the photosensitive drum driving assembly is larger than the actual diameter of the shaft portion of the photosensitive drum driving assembly, and the outer surface 93 of the shaft portion of the photosensitive drum driving assembly is rotatably supported by the inner surface 42 of the circular hole of the side wall 4, And the matching gap between the two is extremely small (usually between 0.05-0.10 mm), so that the outer surface of the shaft portion of the photosensitive drum driving assembly and the inner surface 42 of the circular hole of the side wall 4 are strong. The strong friction causes the required driving force to increase sharply, causing the motor 5 in the image forming apparatus to be overloaded, affecting the life of the motor 5, the gear 6, the gear 7 and the driving force output head 8 of the image forming apparatus, and also affecting the side wall. The use accuracy and life of the inner surface of the circular hole and the outer surface 93 of the shaft portion of the photosensitive drum drive unit. In the transmission mode shown in FIG. 1, the twisted columnar projection 3 of the photosensitive drum drive assembly cooperates with the twisted hole of the driving force output head, and the shaft portion and the gear portion of the photosensitive drum drive assembly and the photosensitive drum drive assembly shown in FIG. The shaft portion and the gear portion are similar and will not be described here.

technical problem

A first object of the present invention is to provide a photosensitive drum driving assembly having a simple structure and reliable performance in view of the defects of the prior art, and the processing cartridge having the photosensitive drum driving assembly has a smooth drop-down, reliable performance, and stable operation.

A second object of the present invention is to provide a photosensitive drum having the above-described photosensitive drum drive unit.

A third object of the present invention is to provide a process cartridge having the above photosensitive drum.

Technical solution

In order to achieve the above first object, the present invention adopts the following technical solution: a photosensitive drum driving assembly for transmitting a rotational driving force output from a driving force output head of an image forming apparatus to a drum body of a photosensitive drum, the driving The assembly includes: a gear that can be tightly fitted to one end of the drum body; an axial adjustment assembly reciprocable relative to the gear in an axial direction of the gear; the axial adjustment assembly includes an output that can be output with the driving force a head-fitting driving force receiving head, a driving rod and a toggle pin, one end of the driving rod being inserted into the inside of the gear along the axial direction, the driving force receiving head being fixed to an outer end of the driving rod and located An outer portion of the gear, the toggle pin is fixed to a portion of the drive rod located in the gear; the gear has a fitable with the toggle pin to limit rotation of the drive rod relative to the gear Blocking part.

In order to achieve the above second object, the present invention adopts the following technical solution: a photosensitive drum is provided, including a drum body, and one end of the drum body is provided with a photosensitive drum driving assembly, and the driving assembly includes: the drum can be tightly fitted to the drum a gear at one end of the body; an axial adjustment assembly reciprocable relative to the gear in an axial direction of the gear; the axial adjustment assembly includes a driving force receiving head and a driving rod engageable with the driving force output head And a toggle pin, one end of the drive rod is inserted into the inside of the gear along the axial direction, and the driving force receiving head is fixed to an outer end of the drive rod and located outside the gear, the toggle A pin is secured to a portion of the drive rod within the gear; the gear has a blocking portion engageable with the toggle pin to limit rotation of the drive rod relative to the gear.

In order to achieve the above third object, the present invention adopts the following technical solution: a process cartridge is designed, including a cartridge body and a photosensitive drum, and the drum body of the photosensitive drum is provided with a photosensitive drum driving assembly at one end thereof, and the driving assembly includes: a gear coupled to one end of the drum body; an axial adjustment assembly reciprocable relative to the gear in an axial direction of the gear; the axial adjustment assembly including a driving force engageable with the driving force output head a receiving head, a driving rod and a toggle pin, one end of the driving rod being inserted into the inside of the gear along the axial direction, the driving force receiving head being fixed to an outer end of the driving rod and located outside the gear The toggle pin is fixed to a portion of the drive rod located within the gear; the gear has a blocking portion engageable with the toggle pin to limit rotation of the drive rod relative to the gear.

Beneficial effect

The invention has the beneficial effects that the axial adjustment component can be moved synchronously along the axial direction of the photosensitive drum to move from the initial position to the working position under the engagement of the driving force output head of the image forming apparatus, and the axial adjustment is utilized. The toggle pin on the assembly and the belt action of the gear inner stop rotate the gear with the driving force output head rotating. The structure of the invention is simple and practical, and the axial adjustment assembly can be reciprocally moved in the axial direction of the photosensitive drum, so that the driving force output head of the image forming apparatus can better mesh with the driving force receiving head of the photosensitive drum. At the start of printing, the driving force output head drives the axial adjustment assembly to rotate about the axis of the driving force output head, and the photosensitive drum gear rotates around the axis of the photosensitive drum, thereby avoiding the supported outer surface of the photosensitive drum gear and the inside of the circular hole of the side wall Strong friction on the surface prolongs the life of the motor, motor drive gear and driving force output head of the image forming apparatus, and improves the precision of the inner surface of the circular hole of the side wall of the process cartridge and the outer surface of the shaft of the photosensitive drum drive assembly. life.

DRAWINGS

1 is a perspective view of a conventional process cartridge.

2 is a schematic view showing the structure of a conventional photosensitive drum in cooperation with a driving force output mechanism of an image forming apparatus.

Figure 3 is a perspective view of a process cartridge of the present invention.

Figure 4 is a perspective view of a photosensitive drum of the present invention.

Figure 5 is a perspective view of the drive assembly on the photosensitive drum shown in Figure 4.

Figure 6 is a partial cross-sectional view of the drive assembly of Figure 5 in an initial state.

Figure 7 is a partial cross-sectional view of the drive assembly of Figure 5 in an operational state.

Figure 8 is a schematic view showing the cooperation relationship between the driving assembly shown in Figure 5 and the driving force output head.

Figure 9 is a longitudinal cross-sectional view of the drive assembly of Figure 5 in engagement with a driving force output head.

Fig. 10 is a cross-sectional view taken along line A-A of Fig. 9;

Figure 11 is a perspective view of a second photosensitive drum drive unit of the present invention.

Figure 12 is a partial cross-sectional view of the drive assembly of Figure 11 in an initial state.

Figure 13 is a partial cross-sectional view of the drive assembly of Figure 11 in an operational state.

Figure 14 is a schematic view showing the cooperation relationship between the driving assembly shown in Figure 11 and the driving force output head.

Figure 15 is a longitudinal cross-sectional view showing the drive assembly of Figure 11 in engagement with a driving force output head.

Fig. 16 is a cross-sectional view taken along line B-B of Fig. 15;

Embodiments of the invention

Embodiment 1

3 is a view showing a process cartridge applied to an image forming apparatus of the present invention, which has substantially the same composition and structure as a conventional process cartridge, and mainly includes a powder silo 1 containing toner and a waste toner silo 2 for collecting waste toner. The powder silo 1 is provided with a mixing frame, a powder feeding roller, a developing roller and the like; the waste toner cartridge 2 is provided with a photosensitive drum 20, a charging roller, a cleaning blade and the like. The powder silo 1 and the waste toner silo 2 are connected by pins or other means. For the sake of clarity of explanation, in each of the following embodiments, the image forming apparatus driving force output mechanism not belonging to the present invention is indicated by a chain double-dashed line, and the same reference numerals in the respective drawings denote the same structures.

Referring to Fig. 4, the photosensitive drum 20 of the present embodiment is composed of a cylindrical drum body 10 having a conductive material on its surface, a drum flange 11 fixed to the left end of the drum body 10, and a photosensitive drum driving assembly 12 at the right end. The driving unit 12 is for transmitting the rotational driving force output from the driving force output head of the image forming apparatus to the photosensitive drum 20 to cause the photosensitive drum 20 to rotate. The photosensitive drum 20 is rotatably supported between the two side walls of the waste toner box 2 through the above-described drum flange 11 and the photosensitive drum drive unit 12, and the photosensitive drum drive unit 12 projects from a circular hole of a side wall 4, which The inner surface of the circular hole rotatably supports the outer circumferential surface of the shaft of the photosensitive drum drive unit 12. The drum drive assembly 12 and the drum flange 11 are also provided with gears for transmitting the received driving force to the other moving members of the process cartridge.

As shown in FIG. 5 and FIG. 6, the photosensitive drum drive assembly 12 is mainly composed of a gear 121 and an axial adjustment assembly 122 disposed on the gear 121. The gear 121 can be tightly fitted to one end of the drum body 10, and the axial adjustment assembly 122 It is reciprocable relative to the gear 121 in the axial direction of the gear 121. The axial adjustment assembly 122 includes a driving force receiving head 123, a driving rod 124 and a dialing pin 125 engageable with the driving force output head 8, wherein the driving rod 124 has a cylindrical shape, and one end thereof is axially inserted into the gear 121. The driving rod 124 is disposed concentrically with the gear 121. The driving force receiving head 123 is fixed to the outer end of the driving rod 124 and located outside the gear 121. The sliding pin 125 passes through and is fixed in the radial direction of the gear 121. The inner end of the drive rod 124 is located inside the gear 121. The gear 121 has a stop 126 as a blocking portion that can cooperate with the toggle pin 125 to limit the rotation of the drive rod 124 relative to the gear 121. The stop 126 allows the toggle pin 125 to be relative to the gear 121 along the axial direction of the gear 121. mobile.

The driving force receiving head 123 includes a disk-shaped substrate 127 fixed to the outer end of the driving rod 124, and the diameter of the substrate 127 is larger than the diameter of the driving rod 124. The outer surface of the substrate 127 is provided with three straight cylindrical protrusions 13 extending along the axial direction, and each of the protrusions 13 has a detachment preventing groove 14 respectively, and a line connecting the three protrusions 13 forms a triangle. . The three projections 13 are evenly distributed on one circumference of the outer surface of the substrate 127, and the center of the circumference is located on the axis of the drive rod 124. The outer end surface of the drive rod 124 protrudes from the outer surface of the substrate 127, and the height of the protruding portion 128 is smaller than the height of the protrusion 13.

Referring to Figs. 7 to 10, when the process cartridge is mounted to the image forming apparatus, the driving force output head 8 of the image forming apparatus cooperates with the photosensitive drum drive unit 12 of the process cartridge. The driving force output head 8 is provided with a recessed hole 81. The cross-sectional shape of the recessed hole 81 is substantially an equilateral triangle, and the inner wall surface of the recessed hole 81 is a twisted surface twisted around the axis, and the twisting direction is toward the opening of the recessed hole 81. Counterclockwise direction. When the recessed hole 81 of the driving force output head 8 is engaged with the driving force receiving head 123 of the photosensitive drum drive unit 12, the driving force output head 8 pulls the axial adjustment unit 122 outward by a certain distance, and the driving force receiving head 123 is initialized. The status changes to the working status. When the driving force output head 8 of the image forming apparatus receives the instruction to start the rotation, the driving force receiving head 123 receives the rotational driving force of the driving force output head 8, causing the axial adjustment component 122 to rotate; the toggle pin 125 of the axial adjustment component 122 passes. Cooperating with the stopper in the gear 121, the gear 121 is rotated, and the photosensitive drum 20 is also rotated.

In order to allow the projections 13 on the photosensitive drum drive unit 12 to smoothly fall into the recessed holes 81 of the driving force output head 8, the front end of each of the projections 13 is formed with a guide plane 15 inclined with respect to the axis of the shaft portion 122. The front end of the projection 13 is made thinner so that it can fall more easily into the recessed hole 81 of the driving force output head 8. As a further embodiment, the guide surface of the front end of the projection 13 can also be designed as a convex curved surface. Thus, in the process of moving the driving force output head 8 toward the projection 13, as long as the opening edge or the inner wall surface of the recessed hole 81 contacts the guiding plane 15 or the guiding curved surface of the front end of the projection 13, the guiding can be followed. The flat surface 15 or the guide curved surface slides in, so that the protrusion 13 smoothly falls into the concave hole 81 through the self-guide and forms a stable fit with the self-guide, thereby eliminating the complicated pre-positioning on the circular hole flange of the side wall of the waste toner box 2. The structure reduces the mold opening difficulty and material cost of the process cartridge frame and simplifies the structure.

When the concave hole 81 on the driving force output head 8 of the image forming apparatus is engaged with the driving force receiving head 123 of the photosensitive drum driving unit 12, the three projections 13 of the photosensitive drum driving unit 12 are respectively subdivided from the three corners of the opening. In the recessed hole 81, each of the projections 13 is engaged with the orifice edge portion 82 of the recessed hole 81 through its retaining groove 14 respectively. The driving force output head 8 pulls the axial adjustment assembly 122 outward by a certain distance, and the driving force receiving head 123 is switched from the initial state to the working state. When the driving force output head 8 of the image forming apparatus receives the instruction to start the rotation, the driving force receiving head 123 receives the rotational driving force of the driving force output head 8, causing the axial adjustment component 122 to rotate; the toggle pin 125 of the axial adjustment component 122 passes. Cooperating with the stopper in the gear 121, the gear 121 is rotated, and the photosensitive drum is also rotated. The anti-drop groove 14 is substantially in point contact with the edge edge 82 of the opening, so that the force is more concentrated and the transmission is more reliable. Meanwhile, in the process of rotationally transmitting the torque, since the orifice edge rib 82 of the recessed hole 81 is engaged in the detachment preventing groove 14 of the projection 13, the photosensitive drum driving assembly 12 is hard to be detached from the driving force output head 8 of the image forming apparatus. The photosensitive drum drive assembly 12 is prevented from being accidentally withdrawn during the transmission process, so that the reliability, stability and print quality of the transmission are further ensured.

Embodiment 2

Referring to FIGS. 11 and 12, the photosensitive drum drive assembly 16 of the present embodiment is similar in structure to the photosensitive drum drive assembly 12 of the first embodiment, and is also composed of a gear 161 and an axial adjustment assembly 162 disposed on the gear 161. The gear 161 can be tightly fitted to one end of the drum body 10, and the axial adjustment assembly 162 can reciprocate relative to the gear 161 along the axial direction of the gear 161. The axial adjustment assembly 162 includes a driving force receiving head 163, a driving lever 164, and a dial pin 165 that are engageable with the driving force output head 8.

The difference is that the driving force receiving head 163 in the photosensitive drum driving unit 16 of the present embodiment is a twisted columnar projection fixed to the front end of the driving lever 164.

Referring to Figs. 13 to 16, when the process cartridge is mounted to the image forming apparatus, the driving force output head 8 of the image forming apparatus cooperates with the photosensitive drum drive unit 16 of the process cartridge. The driving force output head 8 is provided with a recessed hole 81. The cross-sectional shape of the recessed hole 81 is substantially an equilateral triangle, and the inner wall surface of the recessed hole 81 is a twisted surface twisted around the axis, and the twisting direction is toward the opening of the recessed hole 81. Counterclockwise direction. When the recessed hole 81 of the driving force output head 8 is engaged with the driving force receiving head 163 of the photosensitive drum drive unit 16, the driving force output head 8 pulls the axial adjustment unit 162 outward by a certain distance, and the driving force receiving head 163 is initialized. The status changes to the working status. When the driving force output head 8 of the image forming apparatus receives the instruction to start the rotation, the driving force receiving head 163 receives the rotational driving force of the driving force output head 8, causing the axial adjustment component 162 to follow the rotation; the toggle pin 165 of the axial adjustment component 162 passes Cooperating with the stopper in the gear 161, the gear 161 is rotated, and the photosensitive drum is also rotated.

The above description is only a preferred embodiment of the present invention, and the partial structure of the process cartridge is improved or replaced without departing from the concept of the present invention, or the shape, position, and number of protrusions on the photosensitive drum drive assembly. The simple modification or replacement, or the simple modification or replacement of the shape, position, number, and the like of the anti-groove on the projections, such embodiments are all within the scope of the present invention.

Industrial applicability

The photosensitive drum driving assembly, the photosensitive drum and the process cartridge of the present invention can be manufactured and used industrially, and can extend the life of the motor, the motor transmission gear and the driving force output head of the image forming apparatus, and at the same time, improve the round hole in the side wall of the process cartridge. The accuracy and life of the surface of the shaft and the outer surface of the drum drive assembly.

Claims (10)

A photosensitive drum driving assembly for transmitting a rotational driving force outputted by a driving force output head of an image forming apparatus to a drum body of a photosensitive drum, the driving assembly comprising: a gear that can be tightly fitted to one end of the drum body; An axially adjustable component reciprocable relative to the gear along an axial direction of the gear; It is characterized by: The axial adjustment assembly includes a driving force receiving head, a driving rod and a toggle pin engageable with the driving force output head, one end of the driving rod being inserted into the inside of the gear along the axial direction, a driving force receiving head fixed to an outer end of the driving rod and located outside the gear, the toggle pin being fixed to a portion of the driving rod located in the gear; The gear has a blocking portion engageable with the toggle pin to limit rotation of the drive rod relative to the gear. A photosensitive drum drive assembly according to claim 1, wherein said toggle pin passes through an inner end of said drive lever in a radial direction of said gear. A photosensitive drum drive unit according to claim 1, wherein said driving force receiving head is a twisted columnar projection. A photosensitive drum drive assembly according to claim 1, wherein said drive lever is concentric with said gear. A photosensitive drum drive assembly according to claim 1, wherein said driving force receiving head comprises a substrate fixed to an outer end of said driving rod, and said outer surface of said substrate is provided with three extending along said axial direction The protrusions, the lines between the three protrusions form a triangle. A photosensitive drum drive assembly according to claim 5, wherein said three projections are evenly distributed on a circumference of an outer surface of said substrate, and a center of the circumference is located on an axis of said drive rod; The three projections are in the shape of a straight cylinder, and their front ends are formed with guide faces. A photosensitive drum drive unit according to claim 5, wherein an outer end surface of said drive rod protrudes from an outer surface of said substrate, and a height of said protruding portion is smaller than a height of said projection. A photosensitive drum drive unit according to claim 5, wherein said substrate has a disk shape, said drive rod has a cylindrical shape, and said substrate has a diameter larger than a diameter of said drive rod. A photosensitive drum comprising a drum body, characterized in that one end of the drum body is provided with the photosensitive drum driving assembly according to any one of claims 1 to 8. A process cartridge comprising a cartridge body and a photosensitive drum, characterized in that one end of the drum body of the photosensitive drum is provided with the photosensitive drum drive assembly according to any one of claims 1 to 8.

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