JP2006258267A - Electromagnetic clutch unit and image-formation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electromagnetic clutch unit which can transmit high torque and which can increase life-span by transmitting power without sliding or friction. <P>SOLUTION: The electromagnetic clutch unit is provided with an output shaft 1 having gear teeth 1a at the periphery, gear teeth 2a around the output shaft 1, and rotating input member 2. Then, a magnetic circuit is generated by an electromagnetic coil member 3, and the input member 2 and the output shaft 1 are connected to each other, thus the gear teeth 1a and 2a are engaged with each other. Then the energization of the electromagnetic coil member 3 is interrupted, and the connection between the input member 2 and the output shaft 1 is released by centrifugal force. The input member 2 may be split in three or four. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electromagnetic clutch used for various units in an image forming apparatus such as a digital PPC (plain paper copier) and a laser printer, and an image forming apparatus using the electromagnetic clutch.

Conventionally, an electromagnetic clutch transmits torque by forming a magnetic circuit around an amateur and a rotor by an electromagnetic coil. Further, the electromagnetic clutch disclosed in Japanese Patent Application Laid-Open No. 2000-257653 attracts the armature and the rotor by energizing the electromagnetic coil, and further overcomes the reaction force of the spring so that the output member of the rotor faces the input member. The rotation of the input member is transmitted to the output member by engaging the meshing gear of the input member and the meshing gear of the output member.
JP 2000-257653 A

  However, conventional electromagnetic clutches generally require high-accuracy machining and surface treatment on the armature and rotor, and are limited in torque to be transmitted because movement and rotation are transmitted only by a magnetic circuit for connection. There is. Further, the conventional spring clutch has a problem that the square spring and the pipe material need to be processed with high accuracy, and the pipe material is scraped due to the difference in hardness between the square spring and the pipe material, so that there is a limit in the life. Moreover, in the thing of Unexamined-Japanese-Patent No. 2000-257653, since an amateur and a rotor are separated by a spring, there exists a problem in durability of a spring.

  The present invention has been made in view of the above-described problems, and the purpose thereof is that high-precision processing and surface treatment are not required, and high torque can be transmitted without using a friction member. It is an object of the present invention to provide an electromagnetic clutch unit that can achieve a long life by transmitting power without sliding or friction.

  The invention of claim 1 comprises a rotated input member, an output shaft, and an electromagnetic coil member for generating a magnetic circuit, the output shaft having gear teeth around the input member side, The input member is disposed around the output shaft and has gear teeth around the output shaft, and the input member moves relative to the output shaft.

  A second aspect of the present invention is the electromagnetic clutch unit according to the first aspect, wherein the input member approaches the output shaft by a magnetic field generated from a magnetic circuit by the electromagnetic coil member.

  A third aspect of the present invention is the electromagnetic clutch unit according to the first aspect, wherein the input member is moved away from the output shaft by a centrifugal force due to rotation.

  A fourth aspect of the present invention is the electromagnetic clutch unit according to the third aspect, wherein the gear of the input member and the gear of the output shaft are triangular.

  According to a fifth aspect of the present invention, there is provided an image forming apparatus comprising the electromagnetic clutch unit according to any one of the first to fourth aspects.

  According to the first aspect of the present invention, the electromagnetic clutch unit includes an input member to be rotated, an output shaft, and an electromagnetic coil member for generating a magnetic circuit, and the output shaft is disposed around the input member. It has gear teeth, the input member is arranged around the output shaft and has gear teeth around the output shaft side, and the input member moves relative to the output shaft. Therefore, by connecting with the gear teeth of the shaft, the area of the connecting surface can be increased, and higher torque can be transmitted.

  According to the invention of claim 2, in addition to the effect of claim 1, the input member is configured to approach the output shaft by a magnetic field generated from the magnetic circuit by the electromagnetic coil member, and the input member and the output are output by electric energy. The shaft can be connected.

  According to the invention of claim 3, in addition to the effect of claim 1, the input member is configured to move away from the output shaft by a centrifugal force due to rotation, and can be easily disconnected without using any parts. It becomes composition.

  According to the invention of claim 4, in addition to the effect of claim 3, the gear teeth of the input member and the gear teeth of the output shaft have a triangular shape, and can be reliably connected and released.

  According to the invention of claim 5, the image forming apparatus can achieve the effect of any one of claims 1 to 4, and a high-quality image forming apparatus can be obtained.

  Hereinafter, embodiments of the present invention will be described. 1 is a partially cutaway side view of an electromagnetic clutch unit of the embodiment, FIG. 2 is a cross-sectional view taken along line A-A in FIG. 1, and FIG. 3 is an enlarged view of a portion surrounded by an ellipse P in FIG. In FIG. 1, reference numeral 1 denotes an output shaft, 2 denotes an input member, 3 denotes an electromagnetic coil member, 4 denotes a rotary gear, and 5 denotes an input member holding mechanism disposed below the rotary gear 4. The output shaft 1 has gear teeth 1a on the outer periphery, and the input member 2 is disposed around the output shaft 1 and has gear teeth 2a around the output shaft 1 side.

  The input member 2 has a shape obtained by vertically dividing a cylindrical member into two, and the two input members 2 are disposed on the outer periphery of the output shaft 1. Further, the input member 2 is rotated by a mechanism (not shown), and the input members 2 and 2 are movable so as to be separated / approached from the output shaft 1 as indicated by arrows in FIG. ing.

  As shown in FIG. 4, the input member holding mechanism 4 has an input member holding material 5, and a square rod 5 a is formed on the input member holding material 5. Further, the input member 2 is provided with a hole 21, and the rectangular rod 5 a of the input portion holding member 5 is penetrated into the hole 21 of the input member 2 as shown in FIG. 5. Further, the output shaft 1 passes through the input member holding member 5 through the sliding object 7.

  With the above configuration, the input members 2 and 2 are connected to the output shaft 1 by the magnetic field of the electromagnetic coil member 3, and the gear teeth 2a of the input member 2 and the gear teeth 1a of the output shaft 1 are engaged. When the energization of the electromagnetic coil member 3 is stopped and the magnetic field is eliminated, the input member 2 is separated from the output shaft 1 by the centrifugal force due to the rotation, and the connection is released.

  Thus, by connecting with the gear tooth 1a of the output shaft 1 and the gear tooth 2a of the input member 2, the area of a connection surface can be enlarged and transmission of higher torque can be performed. Further, the input members 2 and 2 are configured to approach the output shaft 1 by a magnetic field generated from a magnetic circuit by the electromagnetic coil member 3, and the input member and the output shaft can be connected by electric energy. Furthermore, the input member 2 is configured to move away from the output shaft 1 by a centrifugal force due to rotation, and can be easily disconnected without using any parts, resulting in a simple configuration. Further, as shown in FIG. 3, the gear teeth 2a of the input member 2 and the gear teeth 1a of the output shaft 1 have a triangular shape, and can be reliably connected and released.

  By the way, the image forming apparatus includes a sheet conveying apparatus that conveys a sheet (paper). In this sheet conveying apparatus, the sheet is conveyed with the driving roller and the driven roller sandwiched. At this time, for example, the input member 2 driven roller is connected using, for example, the electromagnetic clutch of the embodiment, and a force that prevents rotation is applied to the driven roller, thereby controlling the sheet conveyance speed. Is called. Since the electromagnetic clutch unit of the embodiment has good durability, a high-quality image forming apparatus can be obtained.

  In the embodiment, the example in which the cylindrical member is divided into two as the input members 2 and 2 has been described, but it may be divided into three, four, and so on.

  Furthermore, in carrying out the present invention, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the object of the present invention.

It is a partially broken side view of the electromagnetic clutch unit of the embodiment of the present invention. It is A-sectional drawing of FIG. FIG. 3 is an enlarged view of a portion surrounded by an ellipse P of an alternate long and short dash line in FIG. 2. It is a figure which shows the input member holding mechanism of embodiment. It is a PP arrow line view of an input member and each FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Output shaft 1a Gear tooth 2 Input member 2a Gear tooth 3 Electromagnetic coil member 5 Input member holding mechanism

Claims (5)

An input member to be rotated, an output shaft, and an electromagnetic coil member for generating a magnetic circuit;
The output shaft has gear teeth around the input member side, the input member is disposed around the output shaft and has gear teeth around the output shaft side,
The electromagnetic clutch unit, wherein the input member moves relative to the output shaft.   The electromagnetic clutch unit according to claim 1, wherein the input member approaches the output shaft by a magnetic field generated from a magnetic circuit by the electromagnetic coil member.   The electromagnetic clutch unit according to claim 1, wherein the input member is moved away from the output shaft by a centrifugal force due to rotation.   The electromagnetic clutch unit according to claim 3, wherein the gear of the input member and the gear of the output shaft are triangular.   An image forming apparatus comprising the electromagnetic clutch unit according to claim 1.

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