JP2008133869A - Motor shaft gear, motor unit and image formation device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that when displacement (rocking) of a motor shaft gear in a radial direction can not be inhibited only by the rigidity of a motor shaft, there is possibility that failure of a motor itself, gears arranged near the motor shaft and the like will be caused. <P>SOLUTION: A motor unit 40 has: the motor shaft gear 163 provided with a stud tubular part 163b rotatably supporting a gear stud 53 which is arranged coaxially with the motor shaft 63; a flapper motor 62 with the motor shaft gear 163 fixed to the motor shaft 63; a flapper motor frame 61 supporting the flapper motor 62; and a drive frame 51 having a gear stud 53 and fixed to the flapper motor frame 61. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor shaft gear, a motor unit including the motor shaft gear, and an image forming apparatus including the motor unit.

Conventionally, there is a motor unit in which a motor and a gear for transmitting a rotational driving force output from the motor are integrally assembled.
In a motor unit including such a motor, the output of the motor is transmitted through meshing of gears. Specifically, a gear is formed on the motor shaft itself, or a gear is fixed to the tip of the motor shaft, and a plurality of gears that freely rotate in parallel with the motor shaft are arranged. The power is transmitted by engaging with each other.

An example of such a motor unit is a motor unit disclosed in Patent Document 1.
In FIG. 3 of Patent Document 1, the motor 7 is fixed to the holding bracket 10, and the first output gear 11 is fixed to the motor shaft of the motor 7, and the first output gear 11 is arranged in parallel with the motor shaft. The state of meshing with the gears 13 and 17 is shown.
JP 2001-147469 A

When a high load is applied to the motor in the motor unit, the force (radial load) acting in the radial direction by the motor shaft gear fixed to the motor shaft cannot be ignored due to the rotational torque. More specifically, when the motor shaft gear that is cantilevered by the motor shaft is subjected to a load such that the motor shaft gear cannot be prevented from being displaced in the radial direction only by the rigidity of the motor shaft, means.
A case where such a high load is applied is, for example, a case where a motor provided in a motor unit is used as a drive source for raising a flapper supporting a recording sheet in a printer to a standby position.
Due to this radial load, the motor shaft tilts the gear stud (gear mounting shaft) arranged in parallel with the motor shaft, or the motor shaft itself is tilted by the reaction of the force with which the motor shaft presses the gear stud. Or the gear may be damaged by the force acting between the motor shaft and the gear stud.
Also, in a motor with a resin case or resin motor shaft, the motor shaft may tilt and the case and the motor shaft may come into contact with each other and wear abnormally. As a result, the motor may be damaged. There is sex.

  In other words, the problem to be solved is that if the rigidity of the motor shaft is not sufficient to suppress the positional deviation (swing) in the radial direction of the motor shaft gear, the motor itself, gears arranged around the motor shaft, etc. There is a possibility that it may cause damage.

  The problems to be solved by the present invention are as described above. Next, means for solving the problems will be described.

The motor shaft gear according to claim 1,
A motor shaft gear fixed to the shaft end of the motor shaft,
A bearing that rotatably supports a shaft member disposed on the same axis as the motor shaft is provided.

The above configuration has the following effects.
The motor shaft gear can be supported at both ends by the motor shaft and the shaft member.

The motor unit according to claim 2 is:
A motor shaft gear according to claim 1;
A motor in which the motor shaft gear is fixed to the motor shaft;
A first frame that supports the motor;
A second frame having the shaft member according to claim 1 and fixed to the first frame;
It is what has.

The above configuration has the following effects.
The motor shaft and the shaft member that support the motor shaft gear at both ends are securely fixed in position.

The image forming apparatus according to claim 3,
The motor unit according to claim 2 is provided.

  As effects of the present invention, the following effects can be obtained.

  Since the motor shaft gear is supported at both ends by the motor shaft and the shaft member, even if a load is applied to the motor shaft gear, not only the rigidity of the motor shaft but also the rigidity of the shaft member is utilized. Misalignment in the radial direction is suppressed.

  Embodiments of the present invention will be described with reference to the drawings.

A schematic configuration of a printer (image forming apparatus) 1 will be described with reference to FIG.
The printer 1 includes a printer main body 2 in which an apparatus related to an image forming process is accommodated, and a paper feed cassette 3 that supplies recording paper.
In particular, the paper feed cassette 3 of the printer 1 is provided with a motor unit 40 for raising the flapper 35.

In the printer 1, a recording paper conveyance path R is formed in a gap such as a frame.
The transport path R is a path for transporting the recording paper supplied from the paper feed cassette 3 via an apparatus related to an image forming process provided in the printer main body 2.
Note that although the printer 1 also has a conveyance path for reverse conveyance when performing double-sided printing, illustration is omitted.

In the printer main body 2, various rollers for conveying the recording paper and each means related to the image forming process are arranged along the conveyance path R.
Specifically, along the transport path R, from the upstream side to the downstream side in the transport direction, as various rollers related to transport, the registration roller pair 4, the photosensitive drum 5 and the transfer roller 6, the heat roller 7, A press roller 8, a transport roller pair 9, and a discharge roller pair 10 are provided. Some of these rollers also serve as means relating to the image forming process. The photosensitive drum 5 is a photosensitive means, the transfer roller 6 is a transfer means, and the heat roller 7 and the press roller 8 are fixing means.
Further, around the outer periphery of the photosensitive drum 5, along the rotation direction of the photosensitive drum 5, a developing roller (developing unit) 11, a charger (charging unit) 12, an LED ( Exposure means) 13 and the like are arranged.

The paper feed cassette 3 includes a flapper 31 on which recording paper is placed, a pickup roller 32, a separation roller 33, and a retard roller 34.
When the pickup roller 32 brought into contact with the upper surface of the recording paper on the flapper 31 rotates, the recording paper on the flapper 31 is fed out toward the rollers 33 and 34.
The pickup roller 32 and the separation roller 33 are means for sending out only one sheet of recording paper to the conveyance path R. The separation roller 33 rotates in a direction in which the recording paper fed out by the pickup roller 32 is sent out to the conveyance path R, and the retard roller 34 rotates so as to send the recording paper back to the flapper 31 side. Even when a plurality of recording sheets are simultaneously fed out by the pickup roller 32, only the recording sheet in contact with the separation roller 33 is supplied to the conveyance path R side, and the other recording sheets are supplied to the retard roller 34. Is returned to the flapper 31 side.
The rollers 33 and 34 constitute the starting end of the transport path R.

Further, the sheet feeding cassette 3 has a flapper arm 35 that contacts the bottom surface of the flapper 31, a drive shaft 36 that rotates the flapper arm 35, and a rotational driving force applied to the drive shaft 36 as means for raising the flapper 31. And a motor unit 40 to be supplied.
Here, the flapper 31 is supported on the casing of the paper feed cassette 3 so as to be rotatable around the rotation shaft 37 at the end on the side opposite to the pickup roller 32. Further, the flapper arm 35 is disposed so as to abut the end portion of the bottom surface of the flapper 31 on the pickup roller 32 side. In addition, the position at which the flapper arm 35 contacts the bottom surface of the flapper 31 by the rotation of the drive shaft 36 is made closer to the end on the pickup roller 32 side. With the above configuration, when the drive shaft 36 supplied with power from the motor unit 40 rotates, the flapper arm 35 rotates and rises, and the flapper 31 is raised around the rotation shaft 37.

The motor unit 40 will be described with reference to FIG.
The motor unit 40 is configured by combining a drive assembly 50 and a flapper motor assembly 60. Each of these assemblies 50 and 60 is a collective part configured by combining a frame and a group of parts supported by the frame. In particular, the flapper motor assembly 60 is provided with a flapper motor 62 as a drive source for raising the flapper 31.
In FIG. 2, the viewpoint shown by the arrow A is a viewpoint when the operator assembles the motor unit 40 to the printer 1. Therefore, the right side in FIG. 2 is the front side of the motor unit 40, and the left side in FIG.

FIG. 2 shows a part of the drive assembly 50.
The drive assembly 50 includes a drive frame 51, a drive motor (not shown), and a gear group (gears 152, 153, 154, etc.) driven by the rotational driving force from the drive motor. Yes.
The drive frame 51 is formed by bending a plate-like member, and includes a mounting plate portion 51a to which a gear or the like is mainly attached, and a plurality of plate portions that are bent with respect to the mounting plate portion 51a. It has. In a state where the drive assembly 50 is attached to the printer 1, the plate surface of the attachment plate portion 51 a is a surface perpendicular to the direction of arrow A.

  A plurality of gear studs (gear mounting shafts) are provided on the front surface of the mounting plate portion 51a so as to protrude in a direction (front side) perpendicular to the mounting plate portion 51a. FIG. 2 shows gear studs 52, 53, and 54 as gear studs provided in the drive frame 51. A double gear 152 is rotatably supported on the gear stud 52, a gear 153 is rotatably supported on the gear stud 53, and a dual gear 154 is rotatably supported on the gear stud 54.

2 and 3 show the flapper motor assembly 60. FIG.
The flapper motor assembly 60 includes a flapper motor frame 61, a flapper motor 62, and a plurality of gears 163, 164, and 165 (described later in detail) that are driven by the rotational driving force from the flapper motor 62. Is provided.
The flapper motor frame 61 is formed by bending a plate-like member, and includes a mounting plate portion 61a to which a gear or the like is mainly attached, and a plurality of plate portions that are bent with respect to the mounting plate portion 61a ( Plate portion 61b and the like). In a state where the flapper motor assembly 60 is attached to the printer 1, the plate surface of the attachment plate portion 61a is a surface perpendicular to the direction of arrow A.

A flapper motor 62 is fixed to the front surface (right end surface in FIG. 2) of the mounting plate portion 61a. The attachment plate portion 61a is formed with an insertion hole for inserting the motor shaft 63 of the flapper motor 62. The motor shaft 63 passes through the attachment plate portion 61a and protrudes rearward of the attachment plate portion 61a. A motor shaft gear 163 is fixed to the tip of the motor shaft 63.
Further, on the rear surface of the mounting plate portion 61a, a plurality of gear studs 64 and 65 are provided in parallel with the motor shaft 53 so as to protrude in a direction perpendicular to the plate surface of the mounting plate portion 61a (rear surface side). . A double gear 164 is rotatably supported on the gear stud 64, and a flapper coupling gear 165 is rotatably supported on the gear stud 65.

  The double gear 164 is formed with a large diameter gear portion 164a and a small diameter gear portion 164b having different outer diameters. And the large diameter gear part 164a and the gear part 163c of the motor shaft gear 163 mesh, and the small diameter gear part 164b and the flapper coupling gear 165 mesh. Thus, when the flapper motor 62 is driven and the motor shaft 53 rotates, the rotational driving force is transmitted to the flapper coupling gear 165 via the motor shaft gear 163 and the double gear 164.

The flapper coupling gear 165 is connected to a drive shaft 36 provided in the paper feed cassette 3 via a coupling mechanism (not shown).
. When the paper feed cassette 3 is pulled out from the printer body 2, the connection between the flapper coupling gear 165 and the drive shaft 36 is released, and when the paper feed cassette 3 is stored in the printer body 2, the flapper coupling gear is removed. 165 and the drive shaft 36 are connected. During this connection, power is transmitted from the flapper coupling gear 165 to the drive shaft 36.

The motor shaft gear 163 will be described with reference to FIGS.
The motor shaft gear 163 is roughly divided into the following three parts having the same axial direction: a motor shaft tube portion 163a into which the motor shaft 63 is inserted, a stud tube portion 163b into which a gear stud is inserted, and a gear portion 163c. And.
The motor shaft cylinder portion 163a and the stud cylinder portion 163b are coaxially arranged at different positions in the axial direction. In particular, in a posture in which the motor shaft gear 163 is fixed to the motor shaft 63, the stud tube portion 163b is located on the tip side of the motor shaft 63 relative to the motor shaft tube portion 163a.
Moreover, the gear part 163c is arrange | positioned at the radial direction outer side of the motor shaft cylinder part 163a.

The motor shaft cylinder portion 163 a is a part for fixing the motor shaft 63 to the motor shaft gear 163 in the motor shaft gear 163.
When the motor shaft 63 is inserted into the motor shaft cylindrical portion 163a, the motor shaft 63 is fixed to the motor shaft cylindrical portion 163a. Specifically, the configuration is as follows. Both the shaft cross-sectional shape of the motor shaft 63 and the shaft cross-sectional shape of the internal space of the motor shaft tube portion 163a into which the motor shaft 63 is inserted (the space surrounded by the inner peripheral surface of the motor shaft tube portion 163a) are both cruciform. And are formed to have substantially the same size. With such a configuration, when the motor shaft 63 is inserted into the motor shaft cylindrical portion 163a, the motor shaft 63 cannot rotate relative to the motor shaft cylindrical portion 163a.
With the above configuration, the motor shaft 63 inserted into the motor shaft cylindrical portion 163a is fixed to the motor shaft gear 163 (incapable of relative rotation around the shaft).

  The stud cylinder part 163b is a part (bearing) that rotatably supports a gear stud arranged coaxially with the motor shaft 63 in the motor shaft gear 163.

  The gear stud arranged coaxially with the motor shaft 63 means a gear stud arranged coaxially with the motor shaft 63 in a state where the motor shaft, the motor shaft gear 163 and its peripheral devices are assembled. In the present embodiment, in a state where the motor unit 40 is configured by combining the drive assembly 50 and the flapper motor assembly 60, the gear stud 53 is arranged on the front end side (rear side) of the motor shaft 63 on the same axis as the motor shaft 63. Is located. That is, the gear stud 53 is a gear stud arranged coaxially with the motor shaft 63.

Moreover, the stud cylinder part 163b functions as means for rotatably supporting the gear stud 53 with the following configuration.
The shaft cross-sectional shape of the gear stud 53 and the shaft cross-sectional shape of the internal space of the stud cylinder portion 163b into which the gear stud 53 is inserted are both circular and have the same size. And if the gear stud 53 is inserted in the stud cylinder part 163b, the gear stud 53 will be supported rotatably with respect to the stud cylinder part 163b.
The axial cross-sectional shape of the gear stud 53 and the axial cross-sectional shape of the internal space of the stud cylindrical portion 163b are substantially the same size, but the axial cross-sectional shape of the internal space of the stud cylindrical portion 163b is slightly larger. ing. In addition, the inner peripheral surface of the stud cylinder portion 163 b is made difficult to be a resistance to rotation of the gear stud 53.

The gear portion 163c is a portion for engaging with another gear adjacent to the motor shaft gear 163 in the motor shaft gear 163 and transmitting the rotational driving force to the other gear.
The gear portion 163c has an annular shape, and is arranged on the outer side in the radial direction of the motor shaft tube portion 163a and fixed to the motor shaft tube portion 163a.

As shown in FIGS. 2 and 6, the motor shaft gear 163 is supported at both ends by the motor shaft 63 and the gear stud 53. The direction in which the motor shaft 63 is inserted into the motor shaft gear 163 and the direction in which the gear stud 53 is inserted are opposite to each other in the axial direction.
The motor shaft 63 is supported by the flapper motor frame 61. This is because the flapper motor 62 having the motor shaft 63 is supported by the flapper motor frame 61. Similarly, the gear stud 53 is supported by the drive frame 51. This is because the gear stud 53 is directly fixed to the drive frame 51.
In addition, when the motor unit 40 is configured and the flapper motor frame 61 is fixed to the drive frame 51, the rear surface of the mounting plate portion 51a and the front surface of the mounting plate portion 61a face each other, and the motor shaft 63 and the gear stud 53 is arranged on the same axis as the opposite. Of course, at k, the flapper motor frame 61 is fixed to the drive frame 51.

As described above, the motor shaft gear 163 has a shape that can be supported at both ends in the axial direction. In the state where the motor shaft gear 163 is supported at both ends by the motor shaft 63 and the gear stud 53, the motor shaft gear 163 is stably supported as compared with the case where the motor shaft 63 is supported by only the cantilever.
Furthermore, because the load applied to the motor shaft gear 163, the motor shaft gear 163 receives a force (radial load) in the radial direction, and the motor shaft gear 163 is displaced (swings) in the radial direction. In this case, because of both-end support, not only the rigidity of the motor shaft 63 but also the rigidity of the gear stud 53 can be used to suppress this positional deviation. For this reason, the rigidity of only the motor shaft 63 can cope with the rigidity of the gear stud 53 even when the displacement of the motor shaft gear 163 in the radial direction cannot be suppressed.

In the present embodiment, the three main parts constituting the motor shaft gear 163, the motor shaft cylinder portion 163a, the stud cylinder portion 163b, and the gear portion 163c are integrally formed of a resin material. Instead of the integrally molded configuration, these three portions may be configured separately and fixed and integrated with each other.
In the present embodiment, the stud cylinder portion 163b is smaller in the radial direction than the motor shaft cylinder portion 163a. This is because the size of the shaft section of the motor shaft 63 is smaller than that of the gear stud 53. It is only because it is larger than the cross section. You may change suitably the magnitude | size of the motor shaft cylinder part 163b and the stud cylinder part 163b.

It is side surface sectional drawing of a printer. It is a side view of a motor unit. It is a rear view of a flapper motor assembly. It is a perspective view of a motor shaft gear. It is a perspective view of a motor shaft gear. It is a principal part perspective view inside a motor unit which shows a mode that a motor shaft gear is supported at both ends.

Explanation of symbols

1 Printer (image forming device)
40 Motor unit 50 Drive assembly 51 Drive frame (second frame)
53 Gear stud (shaft member)
60 flapper motor assembly 61 flapper motor frame (first frame)
62 Flapper motor 163 Motor shaft gear 163a Motor shaft cylinder 163b Stud cylinder (bearing)
163c Gear part

Claims (3)

A motor shaft gear fixed to the shaft end of the motor shaft,
A bearing that rotatably supports a shaft member disposed coaxially with the motor shaft;
A motor shaft gear characterized by that. A motor shaft gear according to claim 1;
A motor in which the motor shaft gear is fixed to the motor shaft;
A first frame that supports the motor;
A second frame having the shaft member according to claim 1 and fixed to the first frame;
A motor unit. The motor unit according to claim 2 is provided.
An image forming apparatus.

Images