JP2024060631A - Driving force transmission structure and image forming apparatus - Google Patents

Abstract

[Problem] To provide a driving force transmission structure and an image forming apparatus capable of stably transmitting driving force even if the rotation center positions of couplings are misaligned. [Solution] The driving force transmission structure has a driving force transmission part that transmits driving force from a driving part, and a driving force receiving part that is inserted into the driving force transmission part and engages with the driving force transmission part to receive the driving force, the driving force transmission part has an engaging part that is movable in a direction intersecting with the insertion direction, and the engaging part engages with the engaged part of the driving force receiving part when the driving force receiving part is inserted. [Selected Figure] Figure 6

Description

The present invention relates to a drive force transmission structure and an image forming device.

In an image forming apparatus that has a rotating body and is equipped with a unit that is detachable from the device body, a driven shaft that is provided in the unit to transmit a driving force to the rotating body, and a drive shaft that receives a driving force from a drive source provided in the device body and is driven to rotate, and that positions the unit within the device body by fitting a positioned part provided in the unit with a positioning part on the device body side, the drive shaft is supported within the device body so that the unit side end of the drive shaft can move in the radial direction, and the image forming apparatus has a female joint that is attached to one of the driven shaft and the drive shaft, has an annular space with one end open, and has multiple track grooves that extend in the axial direction and are formed at equal intervals in the circumferential direction on at least one of the outer wall surface and the inner wall surface of the annular space, and a male joint that is attached to the other shaft, has a part of it incorporated in the annular space of the female joint, and holds a ball that slides along the track grooves formed in the female joint, and connects by inserting the male joint into the annular space of the female joint and engaging the ball held by the male joint with the track groove of the female joint (Patent Document 1).

A process cartridge that is detachable from an electrophotographic image forming apparatus body and includes a motor and an apparatus body side gear that is rotationally driven by the motor and has a connecting hole formed by a twisted surface on the rotation center axis of the apparatus body side gear, and includes an electrophotographic photosensitive drum, a process means that acts on the electrophotographic photosensitive drum, a non-twisted connecting protrusion that is provided at the longitudinal end of the electrophotographic photosensitive drum and that can be fitted into the connecting hole, and an elastic member that urges the process cartridge in the longitudinal direction of the electrophotographic photosensitive drum when the process cartridge is attached to the apparatus body, and when the apparatus body side gear rotates with the connecting protrusion fitted into the connecting hole, the electrophotographic photosensitive drum receives a rotational driving force from the apparatus body via the connecting protrusion that is fitted into the connecting hole (Patent Document 2).

JP 2009-025704 A Japanese Patent Application Laid-Open No. 10-153937

The present invention transmits driving force stably even if the rotational center positions of the couplings are misaligned.

In order to solve the above problem, the driving force transmission structure according to claim 1 comprises:
A driving force transmission structure including: a driving force transmission part that transmits a driving force from a driving part; and a driving force receiving part that is inserted into the driving force transmission part and engages with the driving force transmission part to receive the driving force,
the driving force transmission portion has an engaging portion that is movable in a direction intersecting an insertion direction, and the engaging portion engages with the engaged portion of the driving force receiving portion when the driving force receiving portion is inserted.
It is characterized by:

The invention according to claim 2 provides the driving force transmission structure according to claim 1,
the driving force receiving portion has a protruding portion protruding in an insertion direction, and when the protruding portion is inserted into the driving force transmitting portion, the protruding portion comes into contact with the engaging portion to move the engaging portion in a direction intersecting with the insertion direction;
It is characterized by:

The invention according to claim 3 provides the driving force transmission structure according to claim 2,
the driving force transmission portion further includes a biasing portion that biases the engagement portion in a direction intersecting an insertion direction, and the protrusion moves the engagement portion against the bias of the biasing portion when the protrusion is inserted into the driving force transmission portion.
It is characterized by:

The invention according to claim 4 provides the driving force transmission structure according to claim 3,
the protrusion has a tapered shape tapered toward a tip end side in an insertion direction, and contacts the tapered shape formed on the engagement portion to move the engagement portion in a direction intersecting with the insertion direction;
It is characterized by:

The invention according to claim 5 provides the driving force transmission structure according to claim 4,
the protrusion has a recess capable of receiving the engagement portion in a cross section intersecting with the insertion direction, and when the driving force transmission portion rotates, the engagement portion moves from the recess to engage with the protrusion of the driving force transmission portion.
It is characterized by:

The invention according to claim 6 provides the driving force transmission structure according to claim 5,
The recess is provided in two or more places.
It is characterized by:

In order to solve the above problem, the image forming apparatus according to the seventh aspect of the present invention comprises:
a toner cartridge that is detachably attached to a main body of an image forming apparatus that forms an image on a recording medium using toner and that supplies toner while rotating;
The driving force transmission structure according to any one of claims 1 to 5,
It is characterized by:

According to the invention described in claim 1, driving force can be transmitted stably even if the rotational center positions of the couplings are misaligned.

According to the invention described in claim 2, a constant engagement amount can be obtained by the size of the convex portion, regardless of the amount of misalignment of the rotation centers of the couplings.

According to the invention described in claim 3, this is possible.

The invention described in claim 4 makes it easier to insert the rotational force receiving part into the rotational force applying part.

According to the invention described in claim 5, interference between the protrusion and the engagement portion when inserting the drive force transmission portion can be suppressed.

According to the invention described in claim 6, the engagement portion can be received when the driving force transmission portion is inserted.

According to the invention described in claim 7, the drive can be transmitted stably even if the rotation center positions of the couplings are misaligned when the toner cartridge is attached to the device body.

FIG. 1 is a schematic cross-sectional view illustrating a schematic configuration of an image forming apparatus. FIG. 2 is a perspective view illustrating an overall configuration of the toner cartridge. FIG. 2 is a schematic cross-sectional view of the toner cartridge. FIG. 4 is an exploded perspective view showing the relationship between a transmission member and a coupling gear. 3A is a schematic plan view showing the configuration of a driving force transmission section, and FIG. 3B is a schematic cross-sectional view showing the configuration of the driving force transmission section. 5 is a schematic cross-sectional view illustrating a coupling operation between a driving force transmission portion and a coupling gear as a driving force transmission structure. FIG. FIG. 13 is an exploded perspective view showing the relationship between a transmission member and a coupling gear according to a modified example. 13A and 13B are diagrams illustrating engagement between a protrusion of a coupling gear and an engagement portion according to a modified example.

The present invention will be described in more detail below with reference to the drawings, showing embodiments and specific examples, but the present invention is not limited to these embodiments and specific examples.
In addition, in the following explanation using the drawings, it should be noted that the drawings are schematic and the ratios of the dimensions, etc. may differ from the actual ones, and in order to make it easier to understand, illustrations other than those of parts necessary for the explanation have been appropriately omitted.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is defined as the X-axis direction, the left-right direction as the Y-axis direction, and the up-down direction as the Z-axis direction.

"First embodiment"
(1) Overall Configuration and Operation of Image Forming Apparatus Fig. 1 is a schematic cross-sectional view showing the internal configuration of an image forming apparatus 1 according to this embodiment. The overall configuration and operation of the image forming apparatus 1 will be described below with reference to the drawings.

(1.1) Overall configuration of the image forming device The image forming device 1 is configured to include an image forming unit 10, a paper feeding device 20 attached to the bottom of the image forming unit 10, an operation display unit 30, and an image processing unit 40.

The image forming unit 10 is composed of a system control device 11, an exposure device LH, a photoconductor unit 13, a developing device 14, a transfer device 15, a paper transport device 16, and a fixing device 17, and forms the image information received from the image processing unit 40 as a toner image on the paper P fed from the paper feed device 20.

A paper feeding device 20 having paper trays 21 and 22 is provided at the bottom of the image forming unit 10, and further below the paper feeding device 20, a tray module TM consisting of paper trays T1 and T2 arranged in multiple tiers (two tiers in this embodiment) in the vertical direction and storing paper P is connected to supply paper to the image forming unit 10.
In other words, it is provided with multiple trays that store paper of different types (e.g., material, thickness, paper size, paper grain), and is configured to supply paper fed from one of these multiple trays to the image forming unit 10.

The operation display unit 30 corresponds to a so-called user interface, and specifically comprises a liquid crystal display panel, various operation buttons, a touch panel, etc., and is used for inputting various settings and instructions and displaying information.
The image processing unit 40 generates image data from print information sent from an external device.

(1.2) Configuration and operation of the image forming unit In the image forming device 1 configured as above, paper P is fed from the tray specified for each sheet to be printed in the print job, either from the paper feeding device 20 or the tray module TM, in accordance with the timing of image formation, and is sent to the image forming unit 10.

The photoconductor units 13 are arranged in parallel above the paper feed device 20 (in the Z direction) and include photoconductor drums 31 that are driven to rotate. A developing device 14 having a developing roller 41 is disposed opposite the photoconductor units 13, and above the developing device 14, replaceable toner cartridges TC that contain developer G (toner containing carrier) and a toner supplying device TG that supplies developer G from each toner cartridge TC to the developing device 14 are disposed.
On each of the photoconductor drums 31 on which the electrostatic latent images have been formed by the exposure device LH, toner images of yellow (Y), magenta (M), cyan (C) and black (K) are formed by the respective developing devices 14 .

The transfer device 15 is composed of an intermediate transfer belt 51 onto which the toner images of each color formed on the photosensitive drums 31 of each photosensitive unit 13 are transferred in multiple layers, a primary transfer roller 52 which sequentially transfers (primary transfer) the toner images of each color formed on each photosensitive unit 13 onto the intermediate transfer belt 51, and a secondary transfer roller 62 which transfers (secondary transfer) the toner images of each color transferred in superimposed layers onto the intermediate transfer belt 51 all at once onto a recording medium, i.e., paper.

The color toner images formed on the photoconductor drum 31 of each photoconductor unit 13 are electrostatically transferred (primary transfer) onto the intermediate transfer belt 51 in sequence by the primary transfer roller 52 to which a predetermined transfer voltage is applied from a power supply device (not shown) controlled by the system control device 11, forming a superimposed toner image in which the color toners are superimposed.

The superimposed toner image on the intermediate transfer belt 51 is transported to the secondary transfer section TR where the secondary transfer roller 62 is arranged as the intermediate transfer belt 51 moves. When the superimposed toner image is transported to the secondary transfer section TR, paper P is supplied to the secondary transfer section TR from the paper feeder 20 in accordance with the timing. A predetermined transfer voltage is then applied to the secondary transfer roller 62 from a power supply device controlled by the system control device 11, and the multiple toner images on the intermediate transfer belt 51 are transferred together onto the paper P sent out from the registration roller pair 24.

The fixing device 17 has a heating module 71 and a pressure module 72, and a fixing nip portion NF (fixing area) is formed by the pressure contact area between the heating module 71 and the pressure module 72. The paper P onto which the toner image has been transferred at the secondary transfer portion TR is transported to the fixing device 17 via the transport guide 166 with the toner image still unfixed. The toner image on the paper P transported to the fixing device 17 is fixed by the action of heat and pressure applied by the pair of the heating module 71 and the pressure module 72.

The paper P on which the fixed toner image has been formed is guided to the switching gate G1, and is discharged and stored from the first discharge roller pair 73 into the paper discharge tray section TR1 on the top surface of the image forming device 1. In addition, when the paper is to be inverted for double-sided printing or discharged with the image recording surface facing up, the conveying direction is switched by the switching gate G1 toward the conveying guide 66.

(2) Driving Force Transmission Structure FIG. 2 is a perspective view showing the overall configuration of the toner cartridge TC, FIG. 3 is a schematic cross-sectional view of the toner cartridge TC, FIG. 4 is an exploded perspective view showing the relationship between the transmission member 120 and the coupling gear 130, FIG. 5(a) is a schematic plan view showing the configuration of the driving force transmission unit 200, and FIG. 5(b) is a schematic cross-sectional view showing the configuration of the driving force transmission unit 200.
Hereinafter, the configuration of a toner cartridge TC having a driving force transmission structure according to this embodiment will be described with reference to the drawings.

(2.1) Toner Cartridge As shown in Figures 2 and 3, the toner cartridge TC comprises a container body 100, a holding member 110 that rotatably holds the container body 100, a transmission member 120 that is fixed to the container body 100 and transmits the rotational driving force from the driving force transmission section 200 of the toner supply device TG to the container body 100, and an agitating member AG that rotates in conjunction with the transmission member 120 along the inner surface of the holding member 110 to agitate the developer G in the holding member 110.

The container body 100 is formed by blow molding using polyethylene or polyester resin as a long, roughly cylindrical cylinder with one end closed, and the inner circumferential surface of the cylinder has a spiral portion 101 with a spiral protrusion formed from one end of the cylinder to the other end, and the developer G contained within the cylinder can be transported by the spiral portion 101 by rotating the cylinder in a predetermined direction.

The holding member 110 is shaped so that it can fit together with the toner supplying device TG when it is attached to the toner supplying device TG. When the toner cartridge TC is attached to the toner supplying device TG, the opening/closing cover 112 is pushed in the direction opposite to the attachment direction by the toner supplying device TG (see the arrow in Figure 2), and the discharge port 111 is opened.

As shown in FIG. 4, the transmission member 120 includes a cylindrical outer tube portion 121, a transmission portion 122 that is arranged along the central axis of the outer tube portion 121 and transmits the rotational motion from the driving force transmission portion 200 on the toner supply device TG side, a support portion 123 that is arranged between the transmission portion 122 and the outer tube portion 121 and supports the outer tube portion 121, and an agitation member AG that is arranged on the discharge port 111 side of the support portion 123 of the holding member 110 and agitates the developer G.

The transmission member 120 has a recess 125 formed at approximately the rotation center of the transmission section 122, and a coupling gear 130, which is an example of a driving force receiving section that works in cooperation with the transmission member 120, is inserted into this recess 125 so that the rotational driving force from the driving force transmission section 200 is transmitted to the transmission member 120. In other words, the transmission member 120 and the container body 100 rotate as the coupling gear 130 rotates.

The coupling gear 130 has a gear portion 131 formed on the side facing the transmission member 120, which is inserted into the recess 125 of the transmission member 120. On the toner supply device TG side, which is the insertion side of the coupling gear 130, four protrusions 133 (three are shown in FIG. 4) and a convex portion 134 are formed.

The protrusion 133 is an example of an engaged portion that engages with the engaging portion 220 of the driving force transmission portion 200 of the toner supplying device TG to receive the rotational driving force, and is formed so as to protrude in a substantially triangular shape from the surface 130a of the coupling gear 130.
The protrusion 134 is a boss body that protrudes in the direction in which the toner cartridge TC is inserted into the toner supply device TG, and has a tapered shape 134a formed at the tip side in the insertion direction.

(2.2) Driving Force Transmission Unit As shown in FIG. 5 , the driving force transmission unit 200 includes a main body unit 210, an engaging unit 220 that is movable in the radial direction of the main body unit 210 along a guide groove 212 formed in the main body unit 210, and a biasing unit 230 that biases the engaging unit 220 so as not to protrude outward from the outermost diameter portion 210 a of the main body (see the arrow in FIG. 5 ).

The main body 210 is generally disk-shaped, with a hole 211 formed in the center to receive the protrusion 134 of the coupling gear 130 to be inserted. A guide groove 212 is formed on the surface 210b of the main body 210 on the side where the coupling gear 130 is inserted, and extends from the hole 211 to the outermost diameter portion 210a.

The engaging portion 220 is block-shaped and is fitted into the guide groove 212 so as to be movable in the radial direction of the main body 210. The engaging portion 220 has a tapered shape 220a with an inductive shape on the hole 211 side, and when the protrusion 134 of the coupling gear 130 is inserted toward the hole 211, it moves in the outer diameter direction against the bias of the biasing portion 230 and protrudes outward from the outermost diameter part 210a of the main body 210, and its side comes into contact with and engages with the protrusion 133 of the coupling gear 130 in the rotational direction.

The biasing portion 230 is composed of an elastic body such as a leaf spring or spring, and biases the engagement portion 220 toward the hole 211 inside the guide groove 212. In other words, when the protrusion 134 of the coupling gear 130 is not inserted into the hole 211, the engagement portion 220 does not protrude outward from the outermost diameter portion 210a of the main body portion 210, and the engagement between the driving force transmission portion 200 and the coupling gear 130, which is the driving force receiving portion, is released.

(2.3) Coupling Operation of the Driving Force Transmission Structure FIG. 6 is a schematic cross-sectional view illustrating the coupling operation of the driving force transmission part 200 and the coupling gear 130 as the driving force transmission structure.
In the driving force transmission structure, when the protrusion 134 of the coupling gear 130 of the toner cartridge TC is inserted into the hole 221 of the driving force transmission part 200, the engagement part 220 protrudes outward from the outermost diameter part 210a of the main body part 210 and comes into contact with and engages with the protrusion 133 of the coupling gear 130 in the rotational direction. As a result, the coupling gear 130 rotates, and the transmission member 120 and the container main body 100 rotate.

As shown in FIG. 6(a), when the protrusion 134 of the coupling gear 130 is not inserted, the driving force transmission part 200 is biased in the direction of the hole 211 and is positioned so that the engagement part 220 does not protrude outward from the outermost diameter part 210a of the main body part 210. Also, FIG. 6(a) shows a state in which the driving force transmission part 200 and the coupling gear 130 are engaged with each other with an eccentricity e at their respective rotation center positions.

As shown in FIG. 6(b), when the toner cartridge TC is attached and the protrusion 134 of the coupling gear 130 is inserted, the engaging portion 220 comes into contact with the tapered shape 134a formed on the tip side of the protrusion 134 and moves toward the outermost diameter portion 210a of the main body portion 210, which intersects with the insertion direction, and the engaging portion 220 comes into contact with and engages with the protrusion 133 of the coupling gear 130 in the rotational direction.

Here, as shown in FIG. 6( b ), the amount of engagement d between the protrusion 133 of the coupling gear 130 and the engagement portion 220 is determined by the radial position a of the protrusion 133 of the coupling gear 130, the total radial length b of the engagement portion 220, and the radius c of the convex portion 134 of the coupling gear 130, according to formula (1).
d = b + c - a ... (1)
In other words, since the radial position of the engagement portion 220 is determined regardless of the eccentricity e between the driving force transmission portion 200 and the coupling gear 130, the engagement amount d is kept constant, and the driving force can be transmitted stably even if the rotational center positions of the couplings are misaligned.

"Variations"
FIG. 7 is an exploded perspective view showing the relationship between the transmission member 120 and a coupling gear 130A according to a modified example, and FIG. 8 is a diagram for explaining the engagement between the projection 133 of the coupling gear 130A according to the modified example and an engagement portion 220. As shown in FIG.
As shown in Fig. 7, the protrusion 134A of the coupling gear 130A according to the modified example has a recess 134Aa capable of receiving the engagement portion 220 in a cross section intersecting with the insertion direction. The recess 134Aa is provided in at least two places, and in this embodiment, the recess 134Aa is provided in four places as shown in Figs. 7 and 8.

As shown in FIG. 8(a), when the toner cartridge TC is installed and the protrusion 134A of the coupling gear 130A is inserted, if the protrusion 134A of the coupling gear 130A and the engagement portion 220 are out of phase with each other in the rotational direction, the engagement portion 220 fits into the recess 134Aa of the protrusion 134A and does not engage with the protrusion 133 of the coupling gear 130A.

When the main body 210 (not shown in FIG. 9) of the driving force transmission part 200 rotates from this state, the engaging part 220 fitted in the recess 134Aa of the protrusion 134A moves from the recess 134Aa to the outer diameter part 134Ab of the protrusion 134A (see arrow R1 in FIG. 8B). As a result, the engaging part 220 moves toward the outermost diameter part 210a of the main body 210 intersecting with the insertion direction (see arrow R2 in FIG. 8B), and the engaging part 220 comes into contact with and engages with the protrusion 133 of the coupling gear 130A in the rotational direction.
In this way, by providing a recess 134Aa in the convex portion 134A of the coupling gear 130A, the radial distance of the convex portion 134A can be changed, and it is possible to engage only at necessary points, thereby suppressing interference between the convex portion 134A and the engagement portion 220 when the toner cartridge TC is inserted.

The driving force transmission structure according to this embodiment has a driving force transmission part 200 that transmits the driving force from the toner supply device TG side, and a coupling gear 130 that is inserted into the driving force transmission part 200 and is a driving force receiving part that engages with the driving force transmission part 200 to receive the driving force. The driving force transmission part 200 has an engaging part 220 that is movable in a direction intersecting the insertion direction, and when the coupling gear 130 is inserted, the engaging part 220 engages with a protrusion 133 that is an engaged part of the coupling gear 130. This allows the driving force to be transmitted stably even if the rotation center positions of the driving force transmission part 200 and the coupling gear 130 are misaligned.

1: image forming apparatus, 10: image forming section, 11: system control device, 13: photoconductor unit, 14: developing device,
15: transfer device, 17: fixing device, LH: exposure device,
20: Paper feed device 30: Operation display unit 40: Image processing unit TC: Toner cartridge 100: Container body, 110: Holding member, 120: Transmission member, 130: Coupling gear, 134, 134A: Convex portion 200: Driving force transmission portion 210: Main body portion, 220: Engagement portion G: Developer TG: Toner supply device

Claims (7)

A driving force transmission structure having a driving force transmission part that transmits a driving force from a driving part, and a driving force receiving part that is inserted into the driving force transmission part and engages with the driving force transmission part to receive the driving force,
the driving force transmission portion has an engaging portion that is movable in a direction intersecting an insertion direction, and the engaging portion engages with the engaged portion of the driving force receiving portion when the driving force receiving portion is inserted.
A driving force transmission structure characterized by: the driving force receiving portion has a protruding portion protruding in an insertion direction, and when the protruding portion is inserted into the driving force transmitting portion, the protruding portion comes into contact with the engaging portion to move the engaging portion in a direction intersecting with the insertion direction;
2. The driving force transmission structure according to claim 1 . the driving force transmission portion further includes a biasing portion that biases the engagement portion in a direction intersecting an insertion direction, and the protrusion moves the engagement portion against the bias of the biasing portion when the protrusion is inserted into the driving force transmission portion.
3. The driving force transmission structure according to claim 2. the protrusion has a tapered shape tapered toward a tip end side in an insertion direction, and contacts the tapered shape formed on the engagement portion to move the engagement portion in a direction intersecting with the insertion direction;
4. The driving force transmission structure according to claim 3. the protrusion has a recess capable of receiving the engagement portion in a cross section intersecting with the insertion direction, and when the driving force transmission portion rotates, the engagement portion moves from the recess to engage with the protrusion of the driving force transmission portion.
5. The driving force transmission structure according to claim 4. The recess is provided in two or more places.
6. The driving force transmission structure according to claim 5. a toner cartridge that is detachably attached to a main body of an image forming apparatus that forms an image on a recording medium using toner and that supplies toner while rotating;
The driving force transmission structure according to any one of claims 1 to 5,
1. An image forming apparatus comprising:

Images