JP2009053577A - Shaft holding structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft holding structure capable of improving airtightness between the inside and the outside of a panel, and also, capable of improving an attaching workability. <P>SOLUTION: The shaft holding structure includes: a power transmission gear 29; an output shaft 30 disposed coaxial to the rotation center of the gear 29; a sealing member 31 which is composed of an elastic material, through which the output shaft 30 penetrates; and a container body 25 as the panel having an opening 25a that is engaged with an annular engagement groove 31a formed in the sealing member 31 so as to hold the sealing member 31 together with the output shaft 30. The output shaft 30 is provided with an annular protrusion 30a whose diameter is larger than the inside diameter of a shaft through-hole 31b formed in the sealing member 31. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention provides a power transmission gear, an output shaft provided coaxially with the rotation center of the gear, a seal member made of an elastic material through which the output shaft passes, and the seal member integrally with the output shaft It is related with the axis | shaft holding structure provided with the panel which formed the opening engaged with the cyclic | annular engagement groove formed in the said seal member so that it might hold | maintain.

  2. Description of the Related Art Conventionally, for example, a toner container disposed in an image forming apparatus is well known in which a spiral for agitating and conveying toner stored in a container body is provided.

  The spiral rotates when power from a drive source is transmitted to a gear provided outside the container body.

  Therefore, for example, an output shaft that is provided integrally or separately from the rotation center of the gear and is coupled to the spiral is required between the gear and the spiral. Therefore, the container body holds the output shaft in a penetrating state. There must be.

  At this time, the output shaft penetrating portion of the container body needs to be sealed so that the toner in the container body does not leak outside.

Therefore, as such a shaft holding structure, an elastic member such as a sponge is attached to the output shaft located on the inner wall surface side of the container main body, and the elastic member is crushed between the container main body and the output shaft, thereby causing toner leakage. Techniques for preventing this are known.
Japanese Patent Laying-Open No. 2005-077660

  However, in the shaft holding structure configured as described above, when intense vibration is applied to the toner container, the elastic member such as sponge does not stretch and contract in time, and the temporary contraction between the container main body and the output shaft is not possible. In addition to the occurrence of toner gaps that cause toner leakage, there is a problem that the work of attaching the elastic member to the output shaft is troublesome.

  In view of the above circumstances, an object of the present invention is to provide a shaft holding structure that can improve the airtightness between the inside and outside of the panel and can improve the mounting workability.

  The shaft holding structure of the present invention includes a power transmission gear, an output shaft provided coaxially with the rotation center of the gear, a seal member made of an elastic material through which the output shaft penetrates, and the output shaft. And a panel having an opening that engages with an annular engaging groove formed in the seal member so as to hold the seal member, and the output shaft has a shaft through hole formed in the seal member. An annular protrusion having a diameter larger than the inner diameter is provided.

  At this time, it is preferable that the protrusion is formed at a position at least partially overlapping the opening end surface of the opening when the output shaft is held in the opening via the seal member.

  The seal member is preferably made of a high-density elastic resin material.

  The shaft holding structure of the present invention can improve the airtightness between the inside and outside of the panel, and can improve the mounting workability.

  Next, a toner container according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is an explanatory diagram of a printer as an image forming apparatus equipped with a toner container that employs a shaft holding structure according to an embodiment of the present invention, and FIG. 2 is a toner that employs a shaft holding structure according to an embodiment of the present invention. 3 is a cross-sectional view of the main part of the shaft holding structure according to one embodiment of the present invention, FIG. 4 is an exploded perspective view of the main part of the shaft holding structure according to one embodiment of the present invention, FIG. These are the exploded sectional views of the important section of the axis holding structure concerning one embodiment of the present invention.

  In FIG. 1, a printer 1 as an image forming apparatus is stored in a paper feed cassette 3 slidably stored in a printer main body 2 as an image forming apparatus main body, and a storage space 4 of the paper feed cassette 3. A paper feed unit 5 for taking out the transfer paper (not shown), a manual feed tray 6 installed in front of the printer main body 2, and a manual feed for taking out the transfer paper (not shown) set in the manual feed tray 6. The sheet feeding unit 7, the conveyance path 8 on which the transfer paper supplied from each sheet feeding unit 5, 7 is conveyed, and the upstream side in the sheet conveyance direction of the conveyance path 8 than the merging unit of each sheet feeding unit 5, 7. A registration roller pair 9 disposed on the downstream side in the sheet conveyance direction, an image forming unit 10 disposed on the downstream side in the sheet conveyance direction of the conveyance path 8 relative to the registration roller pair 9 and forming an image on one surface of the transfer paper; Sheet in the conveyance path 8 rather than the forming unit 10 A fixing device 11 that is arranged on the downstream side in the feeding direction and fixes a toner image formed on one surface of the transfer paper, and a fixing device in the conveyance path 8 when an image is formed on the other surface of the transfer paper that has passed through the fixing device 11 11 is provided with a reverse path 12 that pulls back from the downstream side of the transport path 11 to the upstream side of the transport path 8 of the transport path 8 relative to the registration roller pair 9, and a paper discharge unit 13 provided at the end of the transport path 8.

  The image forming unit 10 includes a photosensitive drum 14 and a charger 15, an exposure device 16, a developing device 17, a transfer device 18, a cleaning device 19, and the like disposed around the photosensitive drum 14.

  As a result, in the image forming unit 10, the photosensitive drum 14 is rotationally driven at a predetermined process speed (circumferential speed) by a driving unit (not shown), and the surface thereof is uniformly charged to a predetermined polarity and potential by the charger 15. .

  An electrostatic latent image is formed on the surface of the charged photosensitive drum 14 by the exposure device 16. Here, the exposure device 16 irradiates the surface of the photosensitive drum 14 with the laser beam P based on the image data output from a personal computer or the like, and removes the charge on the laser beam irradiated portion on the surface of the photosensitive drum 14. Thus, an electrostatic latent image corresponding to the image information is formed.

  The electrostatic latent image formed on the surface of the photosensitive drum 14 is developed as an unfixed toner image by electrostatically attaching toner having electric charge supplied from the toner container 20 by the developing unit 17. Further, the unfixed toner image is transferred onto the transfer paper as a transfer image by the transfer unit 18.

  At this time, the photosensitive drum 14 having the unfixed toner image transferred to the transfer paper is subjected to a removal process of residual toner and the like and a charge removal process for charging at the next image formation by the cleaner 19.

(Configuration of developing unit 17)
The developing device 17 supplies the replenishment toner stored in the toner container 20 to the photosensitive drum 14 while stirring. The replenishment toner is supplied from the toner container 20. Further, inside the developing unit 17, first and second spirals 21 and 22 are provided so as to be rotatable in an adjacent state so as to sandwich the partition wall 23. Further, a developing roller 24 is rotatably held in the developing unit 17 so as to be adjacent to the second spiral 22.

  A gap (not shown) is formed at both ends of the partition wall 23 so as to be separated from the inner wall of the developing device 17 so as to communicate between both ends of the spirals 21 and 22 inside the developing device 17. Thus, the replenishment toner supplied from the toner container 20 to one end of the first spiral 21 is agitated and conveyed (forward path) to one side of the developing device 17 and then the partition wall 23 and the developing device 17 on one side thereof. A circulation conveyance path is formed in which the second spiral 22 agitates and conveys (returns) toward the other side of the developing device 17 and returns again at the gap on the other side.

  The developing roller 24 (for example, a magnet roller) is disposed so that the peripheral surface thereof faces the peripheral surface of the photosensitive drum 14. Therefore, the toner being conveyed to the developing roller 24 is supplied to the peripheral surface of the photosensitive drum 14 via the developing roller 24, and the electrostatic latent image formed on the peripheral surface of the photosensitive drum 14 thereby becomes a toner image. Is visualized as

(Configuration of toner container 20)
The toner container 20 includes a container main body 25 in which supply toner is stored, a paddle 26 made of a flexible resin material that rotates to stir the supply toner, and a toner supply formed in the developing unit 17. A spiral 27 is provided that conveys toner for replenishment to a toner supply port (not shown) facing the port (not shown).

  The paddle 26 and the spiral 27 are connected to a toner replenishing motor (not shown) driven and controlled by a known toner replenishing technique based on a toner replenishing signal from an empty sensor (not shown) provided in the developing unit 17 or printing rate control. The drive rotates by being transmitted to the gears 28 and 29 shown in FIG. Each of the spirals 21 and 22 is also rotated synchronously by driving the toner supply motor.

  As shown in FIGS. 3 and 4, the gear 29 includes an output shaft 30 that is coaxially coupled (for example, splined) with the spiral 27 (may be separate).

  As shown in FIG. 5, when the output shaft 30 passes through an opening 25 a formed in the container main body 25 as a panel and is coupled to the spiral 27, the output shaft 30 is sealed by a seal member 31 fitted into the opening 25 a of the container main body 25. It is sealed. Further, an annular protrusion 30 a is integrally formed in the vicinity of the gear 29 of the output shaft 30. The cross-sectional shape of the protrusion 30a is not particularly limited, such as a trapezoid, a rectangle, or a semicircle, but is approximately the thickness (opening end face) of the opening 25a formed in the container body 25 as a panel. It is preferable to form the same or at least a part where they overlap.

  The seal member 31 is made of an elastic and highly airtight resin material, and includes an annular engagement groove 31a that engages with the container body 25 and a shaft through hole 31b through which the output shaft 30 passes. It has been. By the way, the sealing member 31 is not particularly limited as long as it is a resin material (high density elastic resin material) having elasticity and high airtightness. Cell polyurethane foam is preferred.

  Therefore, a dimensional error between the inner diameter of the seal member 31 (the inner diameter of the through hole through which the output shaft 30 passes) and the outer diameter of the output shaft 30, particularly the output shaft 30 than the inner diameter of the shaft through hole 31 b of the seal member 31. Even if the outer diameter of the toner is smaller, the presence of the annular protrusion 30a does not cause an unexpected gap inside the shaft through hole 31b of the seal member 31, and the toner in the container body 25 Is prevented from leaking outside.

  In addition, by forming the protrusion 30a at a position where the protrusion 30a is substantially the same as the opening 25a of the container body 25 (the opening end face) or at least partially overlaps, the seal member 31 is provided between the protrusion 30a and the opening 25a. The toner is compressed, and toner leakage on the opening 25a side can also be prevented.

  Thus, according to the shaft holding structure of the present invention, the container main body 25 can be simply inserted into the container main body 25 by inserting the annular seal member 31 made of an elastic member such as rubber in order to prevent toner leakage from the toner cartridge. Since the engaging groove 31a is engaged with the assembly groove, the assembling workability can be improved. Further, since the annular protrusion 30a is formed on the output shaft 30, the sealing performance with the seal member 31 can be improved, and toner leakage can be prevented.

  In the above embodiment, the shaft holding structure of the present invention is applied to the toner container 20, but it can be applied to general rotation mechanisms such as the gears of the spirals 21 and 22, for example. It is.

  In the present embodiment, there is a gap between the gear 29 and the seal member 31 in the drawing (see FIG. 3). A fluororesin sheet or a Teflon (registered trademark) sheet (coating may be used) having a high coefficient of friction can be provided on one of the surfaces.

1 is an explanatory diagram of a printer as an image forming apparatus equipped with a toner container employing a shaft holding structure according to an embodiment of the invention. FIG. 3 is a perspective view of a toner container employing a shaft holding structure according to an embodiment of the present invention. It is sectional drawing of the principal part of the shaft holding structure which concerns on one Embodiment of this invention. It is a disassembled perspective view of the principal part of the shaft holding structure which concerns on one Embodiment of this invention. It is an exploded sectional view of an important section of a shaft holding structure concerning one embodiment of the present invention.

Explanation of symbols

25 ... Container body (panel)
25a ... Opening 29 ... Gear 30 ... Output shaft 30a ... Projection 31 ... Sealing member 31a ... Engaging groove 31b ... Shaft through hole

Claims (3)

A power transmission gear, an output shaft provided coaxially with the rotation center of the gear, a seal member made of an elastic material through which the output shaft passes, and the seal member held integrally with the output shaft A panel having an opening that engages with an annular engagement groove formed in the seal member,
The shaft holding structure, wherein the output shaft is provided with an annular projection having a diameter larger than the inner diameter of the shaft through hole formed in the seal member.   The said protrusion is formed in the position which at least one part overlaps with the opening end surface of the said opening, when the said output shaft is hold | maintained in the said opening through the said sealing member. Shaft holding structure.   The shaft holding structure according to claim 1, wherein the seal member is made of a high-density elastic resin material.

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