JP2009186551A - Gear mechanism and image forming apparatus using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce noise and to prevent gear skipping. <P>SOLUTION: A gear mechanism is provided with: a gear member 65 with a small diameter section 111 and a large diameter section 112 on which small diameter gears 63 and large diameter gears 64 are respectively formed on the outer peripheries, and are integrally formed with a synthetic resin material with the small diameter section formed to be hollow in a state of being cylindrically protruded from a side surface of the large diameter section; and a restricting member 113 with a restricting section 121 provided inside the small diameter section for restricting deflection of the small diameter section. The outer periphery surface of the restricting section is formed to have a smaller diameter than the inner periphery surface of the small diameter section of the gear member. A gap is provided between the outer periphery surface of the restricting section and the inner periphery surface of the small diameter section, and has a size for limiting the deflection in the small diameter section to be within a range with no occurrence of gear skipping, while allowing the deflection in the small diameter section required for reduction of noise. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a gear mechanism having a gear member made of synthetic resin and an image forming apparatus using the same, and in particular, a gear mechanism having a gear member in which a small diameter gear and a large diameter gear are integrally formed of a synthetic resin material. And an image forming apparatus using the same.

  In an image forming apparatus (such as a printer, a facsimile machine, a copier, and a multifunction machine) that forms an image on recording paper by an electrophotographic process or the like, the rotational force of a motor as a drive source is reduced on a roller that conveys the recording paper. Various types of gear mechanisms are provided for applications such as transmission.

In such a gear mechanism provided in the image forming apparatus, a synthetic resin gear is widely used because of advantages such as noise reduction, omission of lubricant, and cost reduction, and a small diameter gear and a large diameter gear are used. Are integrally formed of a synthetic resin material (Patent Documents 1 and 2). In addition, a technique related to a gear that employs an elastomer material to reduce gear meshing noise is also known (Patent Document 3).
JP-A-6-11016 Japanese Patent Laid-Open No. 10-246313 Japanese Patent Laid-Open No. 9-210145

  However, the synthetic resin gear is effective in reducing noise, but in the case of a structure that directly meshes with the gear of the output shaft of the motor, in addition to the counterpart gear being made of metal, the gear rotates at a high speed. Since a large load acts on the gear at the start of rotation, the noise increases.

  In particular, in the case of a gear made of synthetic resin, in order to increase rigidity, a configuration in which an outer peripheral portion in which teeth are arranged and a central bearing portion are connected to each other by a radial rib is generally used. Due to the influence of sink marks generated on the outer peripheral surface side of the portion, abnormal noise that periodically changes corresponding to the pitch of the ribs is generated. Although such periodic abnormal noise can be solved by increasing the molding accuracy, there is a difficulty in increasing the manufacturing cost, and it is not possible to sufficiently reduce the abnormal noise simply by eliminating the ribs. .

  Therefore, it is conceivable that the gear is formed of a polymer alloy material including an elastomer material that eliminates the ribs and imparts flexibility, so that abnormal noise can be effectively reduced. However, with such a configuration, the outer peripheral portion where the teeth are arranged is easily bent, and if a large load is applied due to a paper jam or the like, tooth skipping occurs. This tooth skipping must be avoided because it causes damage to the teeth and impairs power transmission.

  The present invention has been devised to solve such problems of the prior art, and its main purpose is to reduce gear noise and prevent gear skipping. An object is to provide a mechanism and an image forming apparatus using the mechanism.

  The gear mechanism of the present invention and the image forming apparatus using the same are formed by integrally forming a small diameter portion and a large diameter portion, each of which has a small diameter gear and a large diameter gear, formed of a synthetic resin material on the outer periphery. Has a gear member formed in a hollow shape protruding in a cylindrical shape from a side surface of the large-diameter portion, and a restriction member provided with a restriction portion that is internally provided in the small-diameter portion and restricts bending thereof, and The outer peripheral surface of the portion is formed to have a smaller diameter than the inner peripheral surface of the small-diameter portion of the gear member, and the small-diameter portion of the small-diameter portion required for reducing noise is between the outer peripheral surface of the restricting portion and the inner peripheral surface of the small-diameter portion. A gap having a dimension capable of restricting the bending of the small-diameter portion is provided in a range in which the bending of the small-diameter portion is not caused while allowing the bending.

  According to the present invention, the small-diameter portion is formed hollow in the synthetic resin material and is easily bent, so that it is held in an appropriate meshing state, so that abnormal noise can be effectively reduced. Moreover, since excessive deformation | transformation of a small diameter part is restrict | limited by a limitation member, since sufficient meshing amount can be ensured, tooth skipping can be prevented.

  The first invention made to solve the above-mentioned problem is that the small diameter portion and the large diameter portion, each of which has a small diameter gear and a large diameter gear formed on the outer periphery, are integrally formed of a synthetic resin material, and the small diameter portion Has a gear member formed in a hollow shape protruding in a cylindrical shape from a side surface of the large-diameter portion, and a restriction member provided with a restriction portion that is internally provided in the small-diameter portion and restricts bending thereof, and The outer peripheral surface of the portion is formed to have a smaller diameter than the inner peripheral surface of the small-diameter portion of the gear member, and the small-diameter portion of the small-diameter portion required for reducing noise is between the outer peripheral surface of the restricting portion and the inner peripheral surface of the small-diameter portion. A gap having a dimension capable of restricting the bending of the small-diameter portion is provided in a range in which the bending of the small-diameter portion is not caused while allowing the bending.

  According to this, since the small-diameter portion is formed hollow with the synthetic resin material and is easily bent, the noise is effectively reduced because the small-diameter portion is held in an appropriate meshing state. Moreover, since excessive deformation | transformation of a small diameter part is restrict | limited by a limitation member, since sufficient meshing amount can be ensured, tooth skipping can be prevented.

  In this case, the gear member is made of a polymer alloy such as POM / elastomer, that is, POM (polyacetal), in which a synthetic resin material having excellent mechanical properties such as strength and wear resistance and an elastomer material imparting flexibility are mixed. What mixed the elastomer materials, such as a polyurethane, is suitable. According to this, both mechanical properties and flexibility can be achieved.

  According to a second aspect of the present invention for solving the above-described problems, in the first aspect, the small-diameter gear of the gear member is engaged with a gear formed on an output shaft made of a metal material of a motor that is a drive source. And

  According to this, when the mating gear that meshes with the small-diameter gear portion is made of a highly rigid metal material, abnormal noise becomes noticeable, but the small-diameter portion is formed hollow in the synthetic resin material and easily bends. Sound can be effectively reduced. In addition, when the gear meshing with the small-diameter gear portion is made of a highly rigid metal material, the deformation amount of the small-diameter gear portion is increased, so that tooth skipping is likely to occur, and in particular, a metal If the gear is directly formed on the output shaft, gear skipping is likely to occur because the gear module is small, but excessive deformation of the small-diameter gear portion is limited by the collar member, so tooth skipping is reliably prevented. be able to.

  According to a third aspect of the present invention for solving the above-described problems, in the second aspect, the large-diameter gear of the gear member is a gear provided at the end of an electromagnetic clutch that intermittently transmits power to the driven side. The small-diameter portion of the gear member is disposed on the main body side of the electromagnetic clutch, and the output shaft protrudes from the motor disposed on the side opposite to the large-diameter portion across the small-diameter portion. It is configured to be long in the axial direction so that a required meshing length is ensured between the gear and the small-diameter gear.

  According to this, when the small-diameter portion is formed long in the axial direction, the small-diameter portion formed in the hollow is easily bent, and the deformation amount of the small-diameter portion is increased, so that tooth skipping easily occurs. Since excessive deformation of the small diameter portion is restricted by the member, tooth skipping can be reliably prevented.

  According to a fourth aspect of the present invention for solving the above-described problems, in the first to third aspects of the invention, the gear member projects from the side surface of the large-diameter portion to the small-diameter portion side and enters the center hole. A boss portion for a bearing through which a rotation center shaft is inserted is provided, the restriction member has a center hole into which a boss portion for a bearing of the gear member is inserted, and an inner peripheral surface of the center hole is used for the bearing. It is set as the structure formed larger diameter than the outer peripheral surface of a boss | hub part.

  According to this, coupled with the fact that the outer peripheral surface of the restricting portion of the restricting member is formed to have a smaller diameter than the inner peripheral surface of the small-diameter portion of the gear member, it is between the outer peripheral surface of the restricting portion and the inner peripheral surface of the small-diameter portion. Since a gap having a required dimension is secured, excessive deformation of the small diameter portion can be restricted while allowing the small diameter portion to bend. Further, since the relative rotation between the gear member and the regulating member is allowed, it is possible to reduce friction noise caused by the friction between the outer peripheral surface of the boss portion of the gear member and the inner peripheral surface of the central hole of the regulating member.

  A fifth invention made to solve the above-mentioned problems is that, in the first to fourth inventions, the gear member protrudes from the side surface of the large-diameter portion toward the small-diameter portion and enters the center hole. A boss portion for a bearing through which the rotation center shaft is inserted is provided, and the boss portion for the bearing is provided in a form extending to an outside position from an end opening of the small diameter portion, and the restriction member is A configuration including a flange portion projecting radially outward and abutting on an end face of the small-diameter portion, and a positioning boss portion projecting in the axial direction to a position substantially the same as the tip of the bearing boss portion; To do.

  According to this, the tip of the positioning boss part, together with the bearing boss part of the gear member, comes into contact with the member that defines the axial position thereof, and the axial position on one end side of the regulating member is defined. When the flange portion abuts on the end surface of the small diameter portion, the axial position of the other end side of the restricting member is defined, whereby the restricting member is positioned in the axial direction, and the bending of the small diameter portion can be reliably restricted. it can.

  A sixth invention made to solve the above-mentioned problem is that, in the fifth invention, the restricting member is mounted on the side opposite to the positioning boss portion in a reverse orientation with respect to the gear member. The gear member includes a boss portion for preventing reverse attachment that protrudes in the axial direction to a position ahead of the tip of the boss portion for bearing of the gear member.

  According to this, when the restriction member is attached to the gear member in the reverse direction, the boss portion for preventing reverse attachment protrudes from the boss portion of the gear member, so that it cannot fit in a predetermined attachment space and is difficult to assemble. Therefore, the operator can easily recognize the error and prevent the wrong assembly.

  A seventh invention made to solve the above-described problems is that, in the first to sixth inventions, the restricting portion of the restricting member corresponds to a contact portion with a mating gear that meshes with the small-diameter gear of the gear member. It is set as the structure arrange | positioned at an axial direction position.

  According to this, excessive deformation at the contact portion with the mating gear in the small diameter portion can be accurately limited, so that tooth skipping can be reliably prevented.

  In this case, when the mating gear is arranged with its center line inclined with respect to the center line of the small-diameter gear so that the tip of the mating gear contacts the small-diameter portion with high pressure, What is necessary is just to arrange | position a control part in the axial direction position corresponding to a front-end | tip part.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing an image forming apparatus to which the present invention is applied. The image forming apparatus includes an image forming unit 1 that forms an image on a sheet through charging, exposure, development, transfer, and fixing processes. The image forming unit 1 is accommodated in sheet feeding cassettes 4a to 4d. The sheet S is sequentially fed through the sheet transport unit 2, and the sheet S on which a required image is formed by the image forming unit 1 is discharged to the sheet discharge unit 5.

  The image forming unit 1 includes a plurality of process units 11 to 14 that form toner images for respective colors of yellow, magenta, cyan, and black, and the photosensitive drums 11 a to 14 a in the process units 11 to 14. A laser scanning unit (hereinafter referred to as “LSU”) 16 that scans an image surface with a light beam for exposure, and a toner for each color formed on each of the photosensitive drums 11 a to 14 a in each of the process units 11 to 14. It has an intermediate transfer belt 17 on which images are sequentially transferred and combined, and has a tandem structure in which the photosensitive drums 11 a to 14 a for each color are arranged along the intermediate transfer belt 17.

  In each of the process units 11 to 14, the electrostatic latent image is obtained by scanning the light beam for exposure from the LSU 16 on the image forming surfaces of the photosensitive drums 11a to 14a uniformly charged by the chargers 11b to 14b. An image is formed, and the electrostatic latent images on the respective photoconductive drums 11a to 14a are developed with the respective color toners supplied from the respective developing units 11c to 14c, and single color toner images for the respective colors are formed on the respective photoconductive drums 11a to 11a. 14a is formed on the image forming surface.

  The intermediate transfer belt 17 is supported by being wound around a driving roller 21 and a driven roller 22. Inside the intermediate transfer belt 17, the intermediate transfer belt 17 is pressed to form a toner image on each of the photosensitive drums 11 a to 14 a. Are provided with primary transfer rollers 24 to 27 for each color for transferring the toner image to the intermediate transfer belt 17. Further, a secondary transfer roller 28 for transferring the toner image on the intermediate transfer belt 17 onto the paper S is disposed on the side of the end of the intermediate transfer belt 17.

  The sheet S on which the toner image is transferred by the secondary transfer roller 28 is conveyed to the fixing device 19 and is subjected to a process of fixing the toner image to the sheet S by heat and pressure.

  In the paper transport unit 2, the paper in the first to fourth paper feed cassettes 4a to 4d is taken out by the first to fourth pickup rollers 31a to 31d, respectively, and further the first to fourth paper feed rollers 32a. After being sent out by -32d, it is guided to the registration roller 38 through the first to fourth intermediate rollers 36a-36d. The registration roller 38 synchronizes with the image on the intermediate transfer belt 17 and It is sent to the secondary transfer roller 28.

  The first and second paper feed cassettes 4 a and 4 b are provided in the main body 7, and the third and fourth paper feed cassettes 4 c and 4 d are provided in the optional paper feed stand (extension unit) 8. Further, the registration roller 38 and the first and second intermediate rollers 36a and 36b provided in the main body 7 are driven by a driving mechanism provided in the main body 7, and are provided in third and second optional paper supply stands. The four intermediate rollers 36c and 36d are driven by a drive mechanism provided in an optional paper feed stand.

  As shown below, the drive mechanism on the option paper supply stand 8 side can be switched between standard conveyance at the first speed and high-speed conveyance at the second speed higher than this. The drive mechanism on the main body 7 side can also be switched between standard transport and high-speed transport in conjunction with the drive mechanism on the optional paper feed stand 8 side.

  FIG. 2 is a perspective view showing a drive mechanism on the side of the optional paper feed stand 8 shown in FIG. 3 and 4 are schematic perspective views for explaining the operating state of the drive mechanism shown in FIG.

  The drive mechanism provided in the optional paper supply stand 8 includes a motor 41, a first intermediate roller clutch 42 for intermittently transmitting power from the motor 41 to the third and fourth intermediate rollers 36c and 36d, and the first intermediate roller clutch 42. The one-way clutch 43 provided between the intermediate roller clutch 42 and the intermediate rollers 36c and 36d, and the transmission of power from the shaft 56 on the driving side of the one-way clutch 43 to the intermediate rollers 36c and 36d are intermittently interrupted. The second intermediate roller clutch 44 and a speed reduction mechanism (transmission mechanism) 45 that decelerates and transmits power from the rotor 59 on the driven side of the one-way clutch 43 to the intermediate rollers 36c and 36d.

  The first and second intermediate roller clutches 42 and 44 are electromagnetic clutches, and the shafts 55 and 56 and the rotors 57 and 58 cannot be rotated relative to each other by applying a voltage to the exciting coil. The power transmission between the rotors 57 and 58 is possible, and the power transmission is intermittently performed according to an on / off instruction from a controller (not shown). The one-way clutch 43 is configured to transmit power to the rotor 59 when the shaft 56 rotates in the locking direction.

  The power from the motor 41 is transmitted to the first intermediate roller clutch 42 via a first transmission mechanism 47, and the first transmission mechanism 47 is connected to a gear 62 provided on the output shaft 61 of the motor 41. The gear member 65 includes a small-diameter gear 63 that meshes with the large-diameter gear 64 provided coaxially with the small-diameter gear 63, and the large-diameter gear 64 of the gear member 65 is a first intermediate roller clutch. It meshes with a gear formed on 42 rotors 57.

  The power from the first intermediate roller clutch 42 is transmitted to the one-way clutch 43 and the second intermediate roller clutch 44 via the second transmission mechanism 48, and the second transmission mechanism 48 includes a pair of pulleys. 71 and 72, and a belt 73 wound around the pair of pulleys 71 and 72. One pulley 71 is connected to a shaft 55 penetrating the center of the first intermediate roller clutch 42. The other pulley 72 is connected to a shaft 56 that passes through the central portions of the one-way clutch 43 and the second intermediate roller clutch 44.

  The interlocking mechanism 46 includes a pair of pulleys 75 and 76 and a belt 77 wound around the pair of pulleys 75 and 76. The pulleys 75 and 76 are respectively third and fourth intermediate rollers 36c. Gears 83 and 84 that mesh with gears 81 and 82 that are coaxially connected to the rotation shafts 51 and 52 of 36d are connected to shafts 53 and 54 that are connected to one end.

  The speed reduction mechanism 45 includes a small-diameter gear 67 that is coaxially connected to the rotor 59 of the one-way clutch 43, and a large-diameter gear 68 that meshes with the gear 67. 4 is connected to a shaft 54 that transmits rotation to the intermediate roller 36d. Further, a gear 69 that meshes with a gear formed on the rotor 58 of the second intermediate roller clutch 44 is coaxially connected to the shaft 54.

  In this second drive mechanism, as shown in FIG. 3, when the first intermediate roller clutch 42 is turned on and the second intermediate roller clutch 44 is turned off, the rotational force of the motor 41 causes the transmission mechanisms 47 and 48 to move. At this time, the rotational force of the shaft 56 acts on the one-way clutch 43 in the locking direction and is transmitted to the rotor 59, and is further decelerated via the gears 67 and 65 constituting the reduction mechanism 45. The rotational force is transmitted to the shaft 54, and the third and fourth intermediate rollers 36c and 36d rotate at the first speed.

  At this time, the rotational force of the shaft 54 is input to the rotor 58 of the second intermediate roller clutch 44 via the gear 69. Since the second intermediate roller clutch 44 is off, the second intermediate roller clutch 44 is turned off. The rotor 58 of the roller clutch 44 is idle with respect to the shaft 56.

  As shown in FIG. 4, when both the first and second intermediate roller clutches 42 and 44 are turned on, the rotational force of the motor 41 is transmitted to the shaft 56 through the transmission mechanisms 47 and 48, and the first The second intermediate roller clutch 44 is transmitted from the rotor 58 to the shaft 54 via the gear 69, and the third and fourth intermediate rollers 36c and 36d rotate at the second speed.

  At this time, the rotational force of the shaft 54 is input to the rotor 59 of the one-way clutch 43 via the gear 68 and the gear 67, but the rotation of the rotor 59 is faster than the shaft 56. Since the relative rotation occurs in the free direction, the one-way clutch 43 is idled.

  FIG. 5 is a side view showing the first transmission mechanism 47 shown in FIG. 6 is an exploded perspective view of the first transmission mechanism 47 shown in FIG. FIG. 7 is a cross-sectional view showing the gear member and the regulating member shown in FIG. 5 cut along a plane along the axis. FIG. 8 is a cross-sectional view of the main part shown by cutting the gear member and the regulating member shown in FIG. 7 along a plane perpendicular to the axis. FIG. 9 is a cross-sectional view showing a normal attachment state and an incorrect attachment state of the gear member and the restriction member shown in FIG.

  As shown in FIGS. 5 and 6, the intermediate roller clutch 42 includes a frame (support member) 103 and a bracket (support member) 104 at both ends of a shaft (power transmission shaft) 55 passing through the center via bearings 101 and 102. The bracket 104 is fixed to the frame 103 with screws 105. The shaft 55 is pulled out to the opposite side through a hole formed in the frame 103, and a pulley 71 is attached to a tip portion thereof.

  The gear member 65 is formed by integrally molding a small-diameter portion 111 where the small-diameter gear 63 is formed and a large-diameter portion 112 where the large-diameter gear 64 is formed using a synthetic resin material, and is fixed to the frame 103. A shaft (rotation center axis) 107 is rotatably supported. The tip of the shaft 107 is supported by the bracket 104. A regulating member 113 that regulates the bending of the small diameter portion 111 is internally provided in the small diameter portion 111 of the gear member 65.

  The gear member 65 is a polymer alloy in which a synthetic resin material excellent in mechanical properties such as strength and wear resistance and an elastomer material imparting flexibility are mixed, for example, POM / elastomer, that is, POM (polyacetal) and polyurethane. A mixture of these elastomer materials is preferred. According to this, both mechanical properties and flexibility can be achieved.

  The motor 41 is disposed on the side opposite to the gear member 65 and the intermediate roller clutch 42 with the frame 103 interposed therebetween, and is fixed to the frame 103 with screws 109. The output shaft 61 of the motor 41 protrudes to the gear member 65 side through a hole formed in the frame 103, and a gear 62 provided on the output shaft 61 meshes with the small diameter gear 63 of the gear member 65. The gear 62 of the output shaft 61 is created by gear cutting directly on the metal output shaft 61. The gear 62 of the output shaft 61 and the small diameter gear 63 of the gear member 65 are helical gears.

  The large-diameter gear 64 of the gear member 65 meshes with the gear of the rotor 57 provided at the end of the intermediate roller clutch 42, and the small-diameter portion 111 formed with the small-diameter gear 63 is disposed on the main body 114 side of the intermediate roller clutch 42. The main shaft 114 is elongated in the axial direction so that the gear 62 of the output shaft 61 protrudes from the motor 41 disposed on the side opposite to the large diameter portion 112 with the small diameter portion 111 interposed therebetween. The required meshing length is secured between the small-diameter gear 63 and the small-diameter gear 63.

  As shown in FIG. 7, the small diameter portion 111 of the gear member 65 is formed in a hollow shape so as to protrude in a cylindrical shape from the side surface of the large diameter portion 112. At the center of the gear member 65, a boss portion 117 for a bearing projecting from the side surface of the large diameter portion 112 toward the small diameter portion 111, and a boss portion projecting from the side surface of the large diameter portion 112 to the side opposite to the small diameter portion 111. 118 is provided, and a center hole 116 into which the shaft 107 is loosely inserted is formed so as to penetrate the boss portions 117 and 118 and the large diameter portion 112. In particular, here, no rib is provided to connect the small diameter portion 111 and the central boss portion 117 in the radial direction.

  The restricting member 113 has a restricting portion 121 that restricts the bending of the small diameter portion 111 of the gear member 65. The restricting portion 121 extends in the axial direction from the annular portion 121a and the outer peripheral portion of the annular portion 121a. The cylindrical portion 121b forms an L-shaped cross section. A central hole 122 into which the boss 117 on the small diameter portion 111 side of the gear member 65 is loosely fitted is formed at the center of the restricting member 113, and the restricting member 113 is supported by the boss 117 so as to be relatively rotatable. .

  The restricting member 113 includes a positioning boss 123 protruding in the axial direction from the side surface of the restricting portion 121, and an anti-reverse attachment protruding in the axial direction from the side surface of the restricting portion 121 to the side opposite to the boss portion 123. A boss portion 124 is provided, and a central hole 122 is provided so as to penetrate the boss portions 123 and 124 and the restriction portion 121, and the restriction portion 121 of the gear member 65 when it is externally mounted on the boss portion 117. The fall is regulated by the boss parts 123 and 124. A flange portion 125 that protrudes radially outward and contacts the end surface of the small diameter portion 111 of the gear member 65 is provided on the outer peripheral portion of the restriction portion 121.

  As shown in FIG. 8, the outer peripheral surface forming the circular cross section of the restricting portion 121 of the restricting member 113 is formed to have a slightly smaller diameter than the inner peripheral surface forming the circular cross section of the small diameter portion 111 of the gear member 65. The inner peripheral surface forming the circular cross section of the center hole 122 of the member 113 is formed to have a slightly larger diameter than the outer peripheral surface forming the circular cross section of the boss portion 117 for the bearing of the gear member 65. A gap having a required dimension is formed between the outer peripheral surface of the small diameter portion 111 and the inner peripheral surface of the small diameter portion 111.

  The width d of the gap is set to a dimension that allows the bending of the small-diameter portion 111 required to reduce abnormal noise and limits the bending of the small-diameter portion 111 within a range that does not cause tooth skipping. By appropriately bending, the gear 62 of the output shaft 61 of the motor 41 and the small diameter gear 63 are held in an appropriate meshing state, and noise can be effectively reduced. Since excessive deformation of 111 is limited, a sufficient amount of meshing can be ensured, and tooth skipping can be prevented.

  As shown in FIG. 9, the boss portion 117 on the small diameter portion 111 side of the gear member 65 extends to a position where the boss portion 117 protrudes outward from the end opening of the small diameter portion 111, and the tip of the boss portion 117 contacts the frame 103. In contact therewith, the axial position on one end side of the gear member 65 is defined. Further, the boss portion 118 on the side opposite to the small diameter portion 111 abuts on the bracket 104, and the axial position on the other end side of the gear member 65 is defined, whereby the gear member 65 is greatly displaced in the axial direction. Thus, stable power transmission between the gear of the output shaft 61 of the motor 41 and the small diameter gear 63 and between the large diameter gear 64 and the gear of the rotor 57 of the intermediate roller clutch 42 can be ensured.

  In the restricting member 113, as shown in FIG. 9A, the positioning boss portion 123 protrudes in the axial direction to a position where it is substantially the same as the tip of the boss portion 117 of the gear member 65 in the normal mounting state. The tip of the positioning boss 123 abuts the frame 103, and the axial position on one end side of the regulating member 113 is defined. In addition, since the flange portion 125 abuts against the end surface of the small diameter portion 111, the axial position on the other end side of the regulating member 113 is defined, thereby preventing the regulating member 113 from being greatly displaced in the axial direction. Can be reliably controlled.

  On the other hand, as shown in FIG. 9B, in a state where the regulating member 113 is mounted in the reverse direction, the flange portion 125 abuts on the end surface of the small diameter portion 111, and the axial position on the other end side of the regulating member 113. However, since the boss portion 124 for preventing reverse attachment protrudes in the axial direction to a position ahead of the tip of the boss portion 117 of the gear member 65, the entire state in the assembled state of the gear member 65 and the regulating member 113 is determined. Since the axial dimension becomes larger than that in the normal mounting state and does not fit in the mounting space between the frame 103 and the bracket 104, the assembly becomes difficult and the operator can easily recognize the error.

  10 is a cross-sectional view showing another example of the regulating member shown in FIG. In this restricting member 131, the restricting portion 132 that restricts the bending of the small-diameter portion 111 of the gear member 65 corresponds to the contact portion with the gear 62 of the output shaft 61 of the motor 41 that meshes with the small-diameter gear 63 of the small-diameter portion 111. Placed in position. The restricting portion 132 is formed in a state of projecting in a flange shape outward in the radial direction from a tubular portion 134 having a center hole 133 into which the boss portion 117 of the gear member 65 is loosely inserted.

  A positioning boss portion 135 that abuts the frame 103 and defines an axial position on one end side of the restricting member 131 is formed so as to protrude in the axial direction, and further abuts against the end surface of the small diameter portion 111. A flange portion 136 that defines an axial position on the other end side of the regulating member 113 is formed in a state of projecting radially outward from the tubular portion 134.

  In this configuration, the output shaft 61 is disposed such that the center line thereof is inclined with respect to the center line of the gear member 65, and the tip end portion of the gear 62 of the output shaft 61 contacts the small diameter portion 111 with the highest pressure. In this case, since the restricting portion 132 is disposed at the axial position corresponding to the tip end portion of the gear 62 of the output shaft 61, the end portion of the small diameter portion 111 of the gear member 65 as in the example of FIG. Compared with the configuration in which the restricting portion 121 is disposed, excessive deformation of the small-diameter portion 111 caused by the pressing force of the gear 62 of the output shaft 61 can be accurately limited to prevent tooth skipping with certainty. .

  The gear mechanism and the image forming apparatus using the gear mechanism according to the present invention have an effect of reducing abnormal noise and preventing tooth skipping, and the small diameter gear and the large diameter gear are integrated with a synthetic resin material. The present invention is useful as a gear mechanism having a gear member formed on the image forming apparatus and an image forming apparatus using the gear mechanism.

1 is a schematic configuration diagram showing an image forming apparatus to which the present invention is applied. The perspective view which shows the drive mechanism by the side of the optional paper supply stand shown in FIG. FIG. 2 is a schematic perspective view for explaining the operation state of the drive mechanism shown in FIG. FIG. 2 is a schematic perspective view for explaining the operation state of the drive mechanism shown in FIG. Side view showing the first transmission mechanism shown in FIG. The perspective view which decomposes | disassembles and shows the 1st transmission mechanism shown in FIG. Sectional drawing which cut | disconnects and shows the gear member and control member which were shown in FIG. 5 by the plane along an axis line FIG. 7 is a cross-sectional view of the main part showing the gear member and the regulating member shown in FIG. 7 cut along a plane orthogonal to the axis. Sectional drawing which shows the regular attachment state and incorrect attachment state of the gear member and regulation member which were shown in FIG. Sectional drawing which shows another example of the control member shown in FIG.

Explanation of symbols

8 Optional paper feed stands 36a to 36d Intermediate roller 41 Motor 42 First intermediate roller clutch 43 One-way clutch 44 Second intermediate roller clutch 47 First transmission mechanism 55 Shaft 57 Rotor 61 Output shaft 62 Gear 63 Small diameter gear 64 Large Diameter gear 65 Gear member 101/102 Bearing 103 Frame (support member)
104 Bracket (support member)
107 Shaft (Rotation center axis)
111 Small-diameter portion 112 Large-diameter portion 113 Restriction member 114 Main body 116 Center hole 117 Bearing boss portion 121 Restriction portion 122 Center hole 123 Positioning boss portion 124 Reverse-prevention boss portion 125 Flange portion 131 Restriction member 132 Restriction portion 133 Center hole 135 Boss part 136 for positioning Flange part

Claims (8)

In a mode in which a small diameter portion and a large diameter portion formed by a small diameter gear and a large diameter gear on the outer periphery are integrally formed of a synthetic resin material, and the small diameter portion protrudes in a cylindrical shape from a side surface of the large diameter portion. A gear member formed hollow;
A regulating member provided with a regulating part that is internally mounted in the small-diameter part and regulates the bending thereof;
The outer peripheral surface of the restricting portion is formed to have a smaller diameter than the inner peripheral surface of the small diameter portion of the gear member, and the small diameter required for reducing abnormal noise between the outer peripheral surface of the restricting portion and the inner peripheral surface of the small diameter portion. A gear mechanism characterized in that a gap having a dimension capable of restricting the bending of the small-diameter portion is provided in a range in which the bending of the portion is allowed but the tooth skip does not occur.   The gear mechanism according to claim 1, wherein the small-diameter gear of the gear member meshes with a gear formed on an output shaft made of a metal material of a motor that is a drive source. The large-diameter gear of the gear member meshes with a gear provided at an end of an electromagnetic clutch that intermittently transmits power to the driven side,
A small diameter portion of the gear member is disposed on the main body side of the electromagnetic clutch, and the gear of the output shaft protruding from the motor disposed on the side opposite to the large diameter portion across the small diameter portion and the gear 3. The gear mechanism according to claim 2, wherein the gear mechanism is long in the axial direction so as to ensure a required meshing length with the small-diameter gear. The gear member includes a boss portion for a bearing that protrudes from the side surface of the large-diameter portion toward the small-diameter portion, and into which a rotation center shaft is inserted,
The regulating member includes a center hole into which a bearing boss portion of the gear member is inserted, and an inner peripheral surface of the center hole is formed to have a larger diameter than an outer peripheral surface of the bearing boss portion. The gear mechanism according to any one of claims 1 to 3. The gear member includes a boss portion for a bearing that protrudes from the side surface of the large-diameter portion to the small-diameter portion side, and a rotation center shaft is inserted into the center hole. The boss portion for the bearing is the small-diameter portion. Provided in a manner extending from the end opening of the part to a position that protrudes outward,
The restricting member includes a flange portion protruding outward in the radial direction and abutting against an end face of the small diameter portion, and a positioning boss portion protruding in the axial direction to a position substantially the same as the tip of the bearing boss portion. The gear mechanism according to any one of claims 1 to 4, wherein the gear mechanism is provided.   The regulating member is reversely projected in the axial direction to a position ahead of the tip of the bearing boss portion of the gear member in a reverse mounting state with respect to the gear member on the side opposite to the positioning boss portion. The gear mechanism according to claim 5, further comprising a boss portion for preventing attachment.   The restricting portion of the restricting member is disposed at an axial position corresponding to a contact portion with a mating gear that meshes with a small-diameter gear of the gear member. Gear mechanism.   An image forming apparatus comprising the gear mechanism according to claim 1.

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