JP2019074118A - One-way clutch and image formation device - Google Patents

Abstract

A one-way clutch that is easy to disassemble and excellent in maintainability is provided. In a one-way clutch 100, a needle 120 disposed in each of a plurality of first spaces 108 of a housing 101 and biased in a second space 107 is biased in a direction toward the first space 108 by a magnetic force. A comb-shaped magnet 130 having a plurality of comb-tooth portions 130a and a bridge 130b for connecting the plurality of comb-tooth portions 130a, and is mounted to the housing 101 from the thrust direction of the shaft 140 and attached to the housing 101 The housing 101 includes a comb-shaped magnet 130 configured to be detachable, and a plurality of holes 151 penetrating in the thrust direction are formed in the housing 101 at positions facing the plurality of comb-tooth portions 130a in the thrust direction. [Selection] Figure 10

Description

  The present invention relates to a one-way clutch suitable for an image forming apparatus such as an electrophotographic copying machine, an electrophotographic printer, and an ink jet printer.

  Conventionally, in an image forming apparatus, rotational drive force in one direction is transmitted to a shaft for transmitting rotational drive force to a conveyance roller that conveys a sheet by rotation, and transmission of rotational drive force in the other direction is performed. A configuration is known in which a one-way clutch is mounted to shut off.

  Further, in Patent Document 1, the rollers formed of magnetic material are respectively disposed in a plurality of wedge-shaped spaces formed between the housing and the shaft, and each roller is attached in the direction in which the wedge-shaped space becomes narrow A one-way clutch is described which exerts a chewing effect.

Unexamined-Japanese-Patent No. 03-288025 gazette

  However, in the configuration described in Patent Document 1, the annular projection of the end face is integrated by pressing into a recess formed on the inner peripheral surface of the housing, and once assembled, it is broken apart and disassembled. It was impossible to disassemble. Therefore, maintenance of the one-way clutch and collection of parts are difficult.

  Then, this invention is made in view of such a present condition, and it aims at providing the one-way clutch which was easy to disassemble and was excellent in maintainability.

  A representative configuration of a one-way clutch according to the present invention for achieving the above object is, in a one-way clutch mounted on a shaft, a plurality of first space portions circumferentially adjacent to the first space portion; A housing having a plurality of second space portions having inclined surfaces which are inclined such that the radial width becomes narrower toward the first space portion; and a plurality of the second space portions of the housing A plurality of rotating bodies formed of a magnetic material, wherein when the shaft rotates in a first direction relative to the housing, the shaft engages with the inclined surface to integrally form the shaft and the housing To rotate away from the first space portion when the shaft rotates relative to the housing in a second direction opposite to the first direction. A rotor for relatively rotating the shaft and the housing, and the rotor disposed in the plurality of first spaces of the housing and disposed in the second space by the magnetic force A magnet having a plurality of biasing portions biasing in a direction toward the first space portion, and a connecting portion connecting the plurality of biasing portions, wherein the housing is attached to the housing from the thrust direction of the shaft And a magnet configured to be attachable to and detachable from the housing, the housing penetrating in the thrust direction to a position facing the plurality of biasing portions of the magnet in the thrust direction A plurality of through holes are formed.

  According to the present invention, the one-way clutch can be easily disassembled and excellent in maintainability.

FIG. 1 is a schematic cross-sectional view of an image forming apparatus. It is a perspective view of the one-way clutch of the state with which the shaft was mounted | worn. It is a disassembled perspective view of the one way clutch of the state with which the shaft was mounted | worn. It is the front view and side view of a one way clutch. It is a sectional view of a one way clutch. It is a sectional view and an enlarged view of a one way clutch. They are a rear view and sectional drawing of the one way clutch of the state with which the shaft was mounted | worn. It is a schematic diagram for demonstrating arrangement | positioning of the magnetic pole of a comb-tooth shaped magnet. It is a schematic diagram for demonstrating the decomposition | disassembly method of a one way clutch. It is a schematic diagram for demonstrating the decomposition | disassembly method of a one way clutch. It is a front view of the one way clutch of other composition.

First Embodiment
<Image forming apparatus>
Hereinafter, an entire configuration of an image forming apparatus including a one-way clutch according to a first embodiment of the present invention will be described together with an operation at the time of image formation with reference to the drawings. Note that the dimensions, materials, shapes, relative arrangements, and the like of the components described are not intended to limit the scope of the present invention to them unless otherwise specified.

  The image forming apparatus A transfers toners of four colors of yellow Y, magenta M, cyan C, and black K onto an intermediate transfer belt, and then transfers the image to a sheet to form an image. It is an apparatus. In the following description, members using the toners of the respective colors are suffixed with Y, M, C, and K, except that the configuration and operation of each member are different except for the color of the toner used. Since they are substantially the same, subscripts are appropriately omitted unless distinction is required.

  As shown in FIG. 1, the image forming apparatus A includes an image forming unit for transferring a toner image to a sheet S (recording material), a sheet feeding unit for supplying the sheet S toward the image forming unit, and A fixing unit is provided to fix the toner image.

  The sheet feeding unit feeds the sheet S fed from the pickup roller 71 and the pickup roller 71 (71a to 71d) for picking up the sheet S stacked and stored in the sheet feeding cassette 61 (61a to 61d). It has a roller 77 (77a to 77d). Further, conveyance rollers 76 (76 a to 76 d) and registration rollers 75 disposed downstream of the sheet supply roller 77 in the sheet conveyance direction are provided.

  The rotational driving force of the paper feed roller 77 and the conveyance roller 76 is transmitted from a drive source such as a motor by drive transmission means such as a belt pulley and a gear train. The pitch between the sheet feed roller 77 and the conveyance roller 76 is set to be narrower than the A4 size in the lateral direction 210 mm, and the sheet S is delivered from the sheet feed roller 77 to the conveyance roller 76 in a baton touch manner. .

  Here, a one-way clutch 100 is attached to a shaft 140 (see FIG. 2) for transmitting the rotational driving force of a driving source such as a motor to the sheet feeding roller 77. When the shaft 140 rotates counterclockwise (first direction) by the rotational driving force of the driving source, the one-way clutch 100 transmits the rotational driving force to the sheet feeding roller 77 via a gear (not shown), and rotates clockwise ((1) When rotating in the second direction, the transmission of the rotational driving force is interrupted. The configuration of the one-way clutch 100 will be described in detail later.

  Further, the rotational speed of the conveyance roller 76 is set to be faster than the rotational speed of the paper feed roller 77. As described above, when acceleration is performed by the conveyance roller 76 on the downstream side in the sheet conveyance direction, the conveyed sheet S is pulled by the conveyance speed difference between the conveyance roller 76 and the sheet feeding roller 77. Further, the surface of the transport roller 76 and the sheet feed roller 77 is covered with a material having high frictional force such as rubber, and the sheet S does not slip. Therefore, the rotational speed on the output side is faster than the rotational speed based on the rotational drive force of the drive source input to the one-way clutch 100, and the rotational drive force of the drive source is canceled. Following the conveyance speed of. Thus, the sheet conveyance speed is accelerated on the downstream side in the sheet conveyance direction, and the space between the conveyed sheets S is reduced to improve productivity.

  The image forming unit includes rotatable photosensitive drums 11 (11Y, 11M, 11C, and 11K) as image bearing members, and charging rollers 12 (12Y, 12M, 12C, and 12K) for charging the surface of the photosensitive drums 11. . The image forming apparatus further includes drum cleaners 15 (15Y, 15M, 15C, and 15K), laser scanner units 13 (13Y, 13M, 13C, and 13K), developing devices 14 (14Y, 14M, 14C, and 14K), and an intermediate transfer unit 80.

  The intermediate transfer unit 80 includes a primary transfer roller 35 (35Y, 35M, 35C, 35K), an intermediate transfer belt 31, a secondary transfer roller 41, a secondary transfer opposing roller 32, a drive roller 33, a tension roller 34, a belt cleaner 99 and the like. Equipped with

  The intermediate transfer belt 31 is an endless cylindrical belt stretched around the primary transfer roller 35, the drive roller 33, the tension roller 34, and the secondary transfer counter roller 32. The intermediate transfer belt 31 rotates as the drive roller 33 receives a driving force from a motor (not shown) and is rotated by this rotation to perform a circumferential movement.

  Next, the image forming operation will be described. First, when a control unit (not shown) receives an image forming job signal, the sheet S stacked and stored in the sheet feeding cassette 61 is conveyed to the registration roller 75 by the pickup roller 71, the sheet feeding roller 77, and the conveyance roller 76. The registration roller 75 conveys the sheet S to the image forming unit after the timing of the operation of the image forming unit is matched.

  On the other hand, in the image forming portion, first, a predetermined charging bias is applied to the charging roller 12, whereby the surface of the photosensitive drum 11 is charged. Thereafter, the laser scanner unit 13 irradiates the surface of the photosensitive drum 11 with a laser beam in accordance with an image signal transmitted from an external device (not shown) or the like to form an electrostatic latent image on the surface of the photosensitive drum 11.

  Thereafter, a developing bias is applied to a developing sleeve included in the developing device 14 to supply toner to the electrostatic latent image for development. Thus, toner images of respective colors are formed on the respective photosensitive drums 11.

  The toner image formed on the photosensitive drum 11 is conveyed to the primary transfer portion formed by the photosensitive drum 11 and the primary transfer roller 35 by the rotation of the photosensitive drum 11. Thereafter, in the primary transfer portion, the primary transfer bias of the toner opposite to the regular charging polarity of the toner is applied to the primary transfer roller 35, whereby the toner images of the respective colors are primarily transferred onto the intermediate transfer belt 31.

  Thereafter, the toner image is sent to a secondary transfer portion formed by the secondary transfer roller 41 and the secondary transfer opposing roller 32 by the rotation of the intermediate transfer belt 31. Then, a secondary transfer bias is applied to the secondary transfer roller 41 at the secondary transfer portion, whereby the toner image on the intermediate transfer belt 31 is transferred onto the sheet S.

  The sheet S on which the toner image has been transferred is sent to the fixing device 5 via the conveyance belt 42, and is heated and pressed by the fixing device 5 so that the toner image is fixed to the sheet S. Thereafter, the sheet S on which the toner image is fixed is discharged onto the sheet discharge tray 65 by the discharge roller 82.

  The toner remaining on the surface of the photosensitive drum 11 after the primary transfer is scraped off by the drum cleaner 15 and removed. Similarly, toner remaining on the outer peripheral surface of the intermediate transfer belt 31 after the secondary transfer is scraped off by the belt cleaner 99 and removed.

<One-way clutch>
Next, the configuration of the one-way clutch 100 will be described.

  2 and 3 are a perspective view (including a partially broken surface) and an exploded perspective view of the one-way clutch 100 in a state of being mounted on the shaft 140. FIG. FIG. 4 is a front view (FIG. 4 (a)) and a side view (FIG. 4 (b)) of the one-way clutch 100. FIG. 5A and 5B are a cross-sectional view of the A1-A1 cross section of the one-way clutch 100 (FIG. 5A) and a cross-sectional view of the A2-A2 cross section (FIG. 5B). 6 is a cross-sectional view of the one-way clutch 100 taken along the line A3-A3. FIG. 7 is a rear view (FIG. 7 (a)) of the one-way clutch 100 in a state of being attached to the shaft 140 and a cross-sectional view of the A4-A4 cross section (FIG. 7 (b)).

  As shown in FIGS. 2 to 7, the one-way clutch 100 is configured by combining a needle 120 (rotary body) and a comb-like magnet 130 (magnet) with respect to a housing 101. Further, the shaft 140 is inserted into the shaft hole 150 formed at the center of the housing 101, whereby the one-way clutch 100 is mounted on the shaft 140.

  In the present embodiment, a shaft 140 made of a stainless steel material or aluminum having a diameter of 8 mm and having a hard alumite treatment is fitted in the shaft hole 150 of the housing 101 so as to be freely rotatably fitted by the intermediate compression dimension setting. For example, the diameter of the shaft hole 150 is H8 to H9, and the shaft 140 is set according to a so-called G-shaped center-less abrasive material h7 to h8 with a dimensional accuracy of h7 to h8. It is about 8S.

  The housing 101 is formed of a sintered material of an iron-copper based material having high lubricity and low abrasion, or a sintered material having pores in a sintered material such as iron or zinc. A plurality of detent grooves 102 are formed on the outer peripheral surface of the housing 101. The anti-rotation groove 102 is engaged with a convex portion such as a gear externally fitted to the one-way clutch 100 as a counterpart member of the one-way clutch 100, and the rotation of the housing 101 with respect to the counterpart member is prevented. The arrow-shaped inscription 132 formed on the housing 101 clearly indicates that the one-way clutch 100 transmits the rotational driving force only in one direction.

  In the comb-tooth magnet 130, six comb-tooth portions 130a (biasing portion, projecting portion) are equally disposed at intervals of 60 ° in the circumferential direction, and these comb-tooth portions 130a are annular bridges 130b (connecting portion, It is configured by being connected by an annular portion). The comb-tooth portion 130a is formed to project from the bridge 130b in the thrust direction of the shaft 140, and the tip thereof has a planar shape and a size of approximately 2 mm × 2.7 mm.

  The comb-teeth-shaped magnet 130 is made of a flexible material such as urethane, polyamide elastomer, rubber, or the like, which is compounded by kneading magnetic powder as a compound to give a strong magnetic field to form a magnetic pole. It is a plastic magnet that has. As the magnetic powder, for example, hard magnetic material powder or soft magnetic material such as ferrite, alnico, boron, ferrite, neodymium, cobalt and samarium can be used.

  Further, in the housing 101, first space portions 108 in which the comb teeth 130a of the comb magnet 130 are disposed are formed at six places in the circumferential direction equally. A fitting groove 109 is formed on the inner circumferential surface of the housing 101. After the comb-tooth-shaped magnet 130 is inserted into the first space portion of the housing 101 after the comb-tooth-shaped portion 130 a is inserted into the first space portion of the housing 101, the outer peripheral protrusion 131 (fitting portion) formed on the outer periphery of the bridge 130 b It is press-fit into and fitted, and is held in a state where it does not come off. The comb-like magnet 130 is configured to be removable from the housing 101 by a method described later. That is, the comb-tooth shaped magnet 130 is configured to be attachable to and detachable from the housing 101. The width of the first space portion 108 of the housing 101 decreases in the circumferential direction toward the radial center (the center of the shaft hole 150), so that the comb magnet 130 does not shift to the shaft hole 150 side. Will be held by

  Further, in the flat portion of the housing 101, six through holes 151 having a diameter of about φ1 mm are formed at intervals of 60 ° in the circumferential direction around the shaft hole 150 which is a shaft supporting portion of the shaft 140. The extraction holes 151 are disposed at positions facing each other in the thrust direction of the six comb teeth 130 a of the comb magnet 130 and the shaft 140, and are through holes penetrating in the thrust direction of the shaft 140.

  The needle 120 is a 2 mm diameter metal rod made of magnetic metal such as a parallel pin (Japanese Industrial Standard JIS B 1354-1988). In addition, as a material of the needle 120, for example, martensitic stainless steel SUS440C (Japanese Industrial Standard JIS G4303) which is relatively resistant to rust although it is a magnetic metal can be used.

  In the housing 101, a second space portion 107, in which the needle 120 is disposed so as to be rotatable and rotatable at a position adjacent to the first space portion 108 in the circumferential direction of the one-way clutch 100, is evenly It is located at a place.

  The second space portion 107 has a wedge surface 113 which is a wedge-shaped slope. The wedge surface 113 is a surface having an inclination angle θ (FIG. 6A) of about 7 to 10 ° with respect to a tangent where the shaft 140 and the needle 120 contact, and the first space portion 108 is narrow, The surface is formed such that the opposite side of the first space portion 108 is wide. That is, the second space portion 107 is adjacent to the first space portion in the circumferential direction of the one-way clutch 100, and the wedge surface 113 as an inclined surface inclined so that the width in the radial direction becomes narrower toward the first space portion 108. Is a space with

  Further, in a state in which the comb-teeth-shaped magnet 130 is attached to the first space portion 108, the opening width of the second space portion 107 on the shaft hole 150 side is narrower than the diameter of the needle 120. As a result, when the shaft 140 is not attached, the needle 120 is held without coming off the shaft hole 150 side.

  Further, when the shaft 140 is not attached, the needle 120 is dimensioned so as to project to the center side of the shaft hole 150 more than the rubbing surface 105 which is a surface rubbing against the shaft 140 in the housing 101. Further, the needle 120 is dimensioned so as to contact the shaft 140 formed with the diameter of the minimum tolerance even when the needle 120 is at the position closest to the comb magnet 130 in the second space 107.

  The needle 120 is biased in the direction of the first space 108 by the magnetic force of the comb-like magnet 130 disposed in the first space 108. Further, in the comb-tooth shaped magnet 130, an arc-shaped portion 106 which is an arc-shaped notch is formed at a portion facing the needle 120. The arc portion 106 secures a wide area in which the comb tooth-shaped magnet 130 and the needle 120 approach each other, improves the biasing force of the comb tooth-shaped magnet 130 with respect to the needle 120, and can improve the responsiveness of the one-way clutch 100.

  The housing 101 is impregnated with an appropriate amount of low-viscosity lubricating oil before assembly, and is a so-called oil-impregnated metal. As a result, the lubricating performance of the sliding surface 105 of the housing 101 can be improved, and the wear resistance can be improved. In addition, since the flank on the side of the shaft 140 of the comb-teeth-shaped magnet 130 and in contact with the shaft 140 is a relief surface of lubricating oil, the lubricating effect can be maintained long. Further, fine abrasion powder generated by the friction between the shaft 140 and the needle 120 is magnetically attracted to the flank surface 133, so that the surface of the shaft 140 can be kept clean for a long time.

  Further, in the present embodiment, since the needle 120 is drawn directly to the comb-like magnet 130, the shaft 140 does not have to be a magnetic material. However, in the non-engagement state of the one-way clutch 100 described later, since it becomes a sliding friction type bearing in which the shaft 140 and the sliding surface 105 rub against each other, it is necessary to consider the slidability with respect to this.

  Further, in the present embodiment, since the diameter of the shaft 140 is 8 mm, the dimensional tolerance of the diameter of the shaft 140 is −0.01 mm to −0.05 mm. Further, since the diameter of the needle 120 is 2 mm, the dimensional tolerance of the diameter of the needle 120 is 0 to -0.01 mm. For this reason, the contact position of the needle 120 and the shaft 140 varies in the radial direction. Therefore, in the second space portion 107, the movement surface of the needle 120 is secured, and the wedge surface 113 extends so that the transmission of the drive is performed while maintaining the chewing effect even if the dimensional change occurs.

  FIG. 8 is a schematic view for explaining the arrangement of the magnetic poles of the comb tooth-shaped magnet 130. As shown in FIG. As shown in FIG. 8, it is preferable that the comb-tooth shaped magnet 130 arranges the peaks of the N pole and the S pole within the range of the length of the needle 120 in the longitudinal direction of the needle 120, that is, the thrust direction of the shaft 140. . This is because when the N pole and S pole peaks are disposed at both ends of the comb tooth magnet 130 including the bridge 130 b in the thrust direction, the magnetic force at the tip end of the comb tooth 130 a of the comb magnet 130 and the position of the magnetic pole on the bridge 130 b The magnetic position is different. As a result, a phenomenon occurs in which the arc portion 106 of the comb tooth shaped magnet 130 and the needle 120 are inclined in the longitudinal direction. In this case, a play occurs from an inclined state in the longitudinal direction of the needle 120 to a straight parallel state, the response of the one-way clutch 100 is reduced, and when the inclined needle 120 moves horizontally, a gori There is also an increase in friction torque which is a feeling. On the other hand, when arranging the peaks of the N pole and the S pole of the magnet in the range of the length of the needle 120 in the thrust direction, a magnetic circuit is formed between the needle 120 and the comb magnet 130 and the magnetic force The needle 120 is drawn to the comb-like magnet 130 at the shortest distance. Thus, the needle 120 can be attracted in parallel to the comb tooth shaped magnet 130. In addition, as a processing method, when forming and processing the comb-teeth-shaped magnet 130, a magnet which is a ferromagnetic material is disposed in a forming die, and the peak positions of the S pole and the N pole of the comb-teeth magnet 130 are the needle 120. Try to be within the longitudinal length range.

  Next, the operation of the one-way clutch 100 will be described.

  First, when the shaft 140 rotates counterclockwise, the needle 120 is drawn toward the comb-shaped magnet 130 by the magnetic force of the comb-shaped magnet 130 and bites into and engages with the wedge surface 113 to lose a relief. As a result, the contact surface pressure between the wedge surface 113 and the needle 120 is increased, and the housing 101 is brought into an engaged state to rotate with the shaft 140 by the wedge effect. That is, when the shaft 140 rotates counterclockwise, the rotational driving force of the shaft 140 is transmitted to a gear or the like externally fitted to the housing 101.

  On the other hand, when the shaft 140 is rotated clockwise, the needle 120 resists the magnetic force of the comb-like magnet 130 and is opposite to the first space 108 in which the comb-like magnet 130 is disposed in the second space 107. Move to a space where the radial width on the side is wide. As a result, the needle 120 is released from biting into the wedge surface 113, the contact surface pressure between the wedge surface 113 and the needle 120 decreases, the needle 120 rotates, and the shaft 140 and the housing 101 relatively rotate (shaft 140 is idled). That is, when the shaft 140 rotates clockwise, the rotational driving force of the shaft 140 is not transmitted to the gear externally fitted to the housing 101 or the like. In this manner, the one-way clutch 100 transmits only rotational driving force in one direction of the shaft 140 to a gear or the like (not shown).

  In addition, although this embodiment demonstrated the structure which the shaft 140 receives rotation driving force and rotates, this invention is not limited to this. That is, the gear externally fitted to the housing 101 may be configured to rotate by receiving the transmission of the rotational driving force from another gear or the like.

  In this case, when the gear externally fitted to the housing 101 is rotated clockwise, the needle 120 is drawn toward the comb magnet 130 by the magnetic force of the comb magnet 130 and bites into and engages with the wedge surface 113 to escape. lose. As a result, the contact surface pressure between the wedge surface 113 and the needle 120 becomes high, and the housing 101 and the shaft 140 are brought into an engaged state in which they are integrally rotated by the wedge effect. That is, when the shaft 140 rotates counterclockwise relative to the housing, transmission of rotational driving force is performed between the shaft 140 and the one-way clutch 100.

  On the other hand, when the gear externally fitted to the housing 101 rotates counterclockwise, the needle 120 resists the magnetic force of the comb magnet 130 and the comb magnet 130 is disposed in the second space 107. It moves to the opposite side to the first space portion 108. As a result, the needle 120 is released from biting into the wedge surface 113, the contact surface pressure between the wedge surface 113 and the needle 120 decreases, and the shaft 140 and the housing 101 rotate relative to each other (the housing 101 rotates idle). It will be in the engaged state. That is, when the shaft 140 rotates in the clockwise direction relative to the housing, transmission of rotational driving force is not performed between the shaft 140 and the one-way clutch 100.

<How to disassemble the one-way clutch>
Next, a method of disassembling the one-way clutch 100 will be described.

  9 and 10 are schematic views for explaining the disassembling method of the one-way clutch 100. FIG. As shown in FIGS. 9 and 10, the disassembling tool 153 for disassembling the one-way clutch 100 has a configuration in which six drawing pins 154, which are metal rods with a diameter of about 0.9 mm, are erected on the base surface 156. The six extraction pins 154 have the same length. Further, in the present embodiment, although the tip of the extraction pin 154 has a planar shape, it may be chamfered or a rounded shape in consideration of workability and ease of insertion.

  When disassembling the one-way clutch 100, the extraction pin 154 of the disassembly tool 153 is inserted and pushed from the thrust direction of the shaft 140 attached to the one-way clutch 100 with respect to six extraction holes 151 formed in the housing 101 . As a result, the comb-tooth portion 130 a of the comb-tooth shaped magnet 130 facing the extraction hole 151 abuts on the extraction pin 154. Thereafter, the extraction pin 154 is further pushed until the housing 101 and the base surface 156 of the disassembly tool 153 abut.

  As a result, the comb-teeth shaped magnet 130 is pushed out and separated from the housing 101 in the thrust direction. Further, when the comb-tooth shaped magnet 130 is pushed out, the needle 120 is pulled out of the housing 101 without dropping while being attracted to the comb-tooth shaped magnet 130. Finally, the housing 101 is pulled out of the extraction pin 154. In addition, since the extraction hole 151 and the extraction pin 154 have a backlash in size and are fitted, the housing 101 is easily detached. The one-way clutch 100 is disassembled by the above method.

  As described above, in the configuration of the present embodiment, the comb-tooth shaped magnet 130 is attached to the housing 101 in the thrust direction of the shaft 140 and configured to be detachable from the housing 101. Further, in the housing 101, at the position where the comb teeth 130a of the comb magnet 130 and the shaft 140 are opposed in the thrust direction, an ejection hole 151 penetrating in the thrust direction is formed. Thus, in the one-way clutch 100, the housing 101, the comb-like magnet 130 and the needle 120 can be easily disassembled. Therefore, the one-way clutch 100 can be easily disassembled and excellent in maintainability.

  In addition, because one-way clutch 100 is easy to disassemble, if a defective product is installed or a defect occurs in inspection after manufacturing, these can be disassembled to determine the cause of defective parts, and the defective product can be replaced by defective parts. It is possible to reduce the yield and stabilize the quality by rearranging. Furthermore, material separation and recovery at the time of disposal becomes easy, and in particular, when expensive rare earth is used as the material of the comb-teeth-shaped magnet 130, reuse by separation after recovery can be promoted.

  In the present embodiment, the configuration has been described in which the number of the through holes 151 formed in the housing 101 of the one-way clutch 100 and the number of the comb teeth of the comb magnet 130 are the same. However, the present invention is not limited to this. That is, as shown in FIG. 11, the same effect as described above can be obtained even if the number of the extraction holes 151 is two for the six comb teeth of the comb magnet 130, for example. In this case, the number of extraction pins 154 of the disassembly tool 153 is also two.

  Further, in the configuration shown in FIG. 11, the circumferential interval of the extraction holes 151 is 180 °. Thus, by setting the interval in the circumferential direction of the extraction holes 151 to be 90 ° or more, it is possible to suppress breakage when the bridge 130b of the comb tooth shaped magnet 130 is inclined and scratched when the comb tooth shaped magnet 130 is pushed out. .

  In the present embodiment, the image forming apparatus A is described as an example of the article on which the one-way clutch 100 is mounted, but the present invention is not limited thereto, and the same effects can be obtained even when used for other articles. Can.

77: Paper feed roller (conveying roller)
DESCRIPTION OF SYMBOLS 100 ... One-way clutch 101 ... Housing 107 ... 2nd space part 108 ... 1st space part 113 ... 楔 surface (inclined surface)
120 ... needle (rotary body)
130 ... comb-shaped magnet (magnet)
130a ... comb-tooth portion (biasing portion, projecting portion)
130b ... bridge (connection part, annular part)
131 ・ ・ ・ Outer peripheral projection (fitting part)
140 ... shaft 150 ... shaft hole (hole through which the shaft passes)
151 ... Penetration hole (through hole)
A: Image forming apparatus

Claims (8)

In the one-way clutch mounted on the shaft,
A plurality of first space portions, and a plurality of second space portions that are adjacent to the first space portion in the circumferential direction and have inclined surfaces that are inclined such that the radial width becomes narrower toward the first space portion And a housing having
A plurality of rotating bodies respectively disposed in the plurality of second space portions of the housing and formed of a magnetic material, wherein the sloped surface rotates in the first direction relative to the housing relative to the housing And integrally rotate the shaft and the housing, and the first space when the shaft rotates relative to the housing in a second direction opposite to the first direction. A rotating body that moves in a direction away from the unit to relatively rotate the shaft and the housing;
A plurality of biasing portions disposed respectively in the plurality of first space portions of the housing and biasing the rotating body disposed in the second space portion in a direction toward the first space portion by a magnetic force; A magnet having a connecting portion for connecting the plurality of biasing portions, the magnet mounted on the housing from the thrust direction of the shaft and configured to be detachable from the housing;
Equipped with
In the housing, a plurality of through holes penetrating in the thrust direction are formed at positions facing the plurality of urging portions of the magnet in the thrust direction.   The one-way clutch according to claim 1, wherein the through hole of the housing is formed at an interval of at least 90 ° in a circumferential direction with respect to a center of a hole through which the shaft is inserted.   The one-way clutch according to claim 1, wherein the through holes of the housing are formed in the same number as the plurality of the biasing portions of the magnet.   The peak of the S pole and the N pole is disposed within the range of the length in the longitudinal direction of the rotating body of the surface of the urging portion facing the rotating body, and the magnet is characterized in that The one-way clutch according to any one of to 3.   The magnet according to any one of claims 1 to 4, wherein in the magnet, the connection portion is a ring portion, and the biasing portion is a protruding portion protruding in the thrust direction from the ring portion. One-way clutch described.   The one-way clutch according to claim 5, wherein a projection that protrudes in the radial direction is formed on the outer peripheral surface of the annular portion as a fitting portion to be fitted to the housing.   The one-way clutch according to any one of claims 1 to 6, wherein the magnet has flexibility. An image forming unit that forms an image on a recording material;
A conveyance roller that rotates to convey the recording material;
Equipped with
An image forming apparatus, wherein the one-way clutch according to any one of claims 1 to 7 is mounted on a shaft for transmitting a drive to the transport roller.

Images