JP2508616Y2 - Gear coupling device - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to a gear coupling device that is detachable.

[Conventional technology]

5 and 6, the upper casing 1 is arranged to be openable and closable with respect to the lower casing 2, and the process cartridge 3 is detachably attached to the upper casing 1 and the upper casing 1 is closed. 1 shows an image forming apparatus used in this state. In this image forming apparatus, the drive shaft 5 of the photoconductor 4 of the process cartridge 3 is provided in the lower housing 2 with the upper housing 1 thereof being closed. In this state, the driven gear 8 rotatably fixedly supported by the drive shaft 5 is engaged with the support groove 7 provided on the support member 6 so as to be opened upward, and is supported by the lower housing 2 side. It is adapted to mesh with the drive gear 9.

As described above, the coupling between the driven gear 8 and the drive gear 9 in the image forming apparatus is disengaged each time the upper casing 1 is opened and closed. It is desirable to connect smoothly every time the closing operation of.

Therefore, conventionally, in the gear coupling device, for example,
As shown in (1) JP-A-60-4646 and (2) JP-A-58-25646, various ideas have been proposed.

In the first conventional example, the moving gear is supported without play of the moving frame body, and the fixed gear is pushed by the tooth tip hitting when the moving gear is connected. It moves only against the spring, and then connects by rotating the gear.

Further, in the second conventional example, both gears to be connected are connected via an elastic member.

[Problems to be Solved by the Invention] In any of the above-mentioned conventional devices, the drive-side gear has a play in the rotational direction. In the case of the device, there is a problem that unevenness occurs in the image.

In addition, it is conceivable to process the tooth tips of the gears that are connected to each other, but this is not a problem in the case of spur gears, but it is difficult to implement it in helical gears.

Now, in the above image forming apparatus, the ease of meshing of the driven gear 8 and the drive gear 9 when the upper housing 1 is closed is as follows.
The positional relationship between both gears 8 and 9 is greatly related.

For example, module 1, pressure angle 20 °, helical angle 20 °
As shown in FIG. 7, when the relative angle between the two gears 8 and 9 is 20 °, the tooth tip of the driven gear 8 comes to the tooth tip of the drive gear 9 with a probability of 20/100. It abuts. Further, as shown in FIG. 8, when the relative angle between both gears 8 and 9 is 30 °, the probability is 50/100. As an ideal state in which the tooth tips of both gears 8 and 9 do not come into contact with each other, as shown in FIG. 9, a positional relationship in which the relative angle is 90 ° is good, but with this, with respect to the rotation of the drive gear 9, As a result, the driven gear 8 is allowed to escape, resulting in a large loss of power transmission.

In addition, increasing the relative angle in this way is not possible due to the internal structure of the machine.

The present invention has been made in view of the above, and the gear supported on the lower housing side is the drive side gear, and the gear supported on the upper housing side is the driven gear. The driven gear can be smoothly engaged with this drive gear without play, and when the driven gear meshes with the drive gear, the lower housing side does not become misaligned via the support member. It can be supported and does not generate vibration when meshing with both gears, and when this gear coupling device is used in a process cartridge type image forming apparatus, it is possible to prevent the occurrence of image unevenness due to the pitch change of the gear of the gear coupling device, It is another object of the present invention to provide a gear coupling device having a simple structure.

[Means for solving the problem]

In order to achieve the above-mentioned object, a gear coupling device according to the present invention comprises a gear rotatably fixedly supported on a lower housing, and a gear which is opened and closed in parallel with the axis of the gear of the lower housing. It is provided in the upper case that can be opened and closed around the axis,
In addition, in the gear coupling device including the gear that engages with the gear on the lower housing side by the closing operation of the upper housing, play the gear on the upper housing side in a direction perpendicular to the opening / closing axis of the upper housing. A support member that supports the support shaft of the gear on the upper housing side in a state in which both gears are normally engaged, is provided with the support shaft being releasable from above. Also, it is provided on the lower casing side so as to be supported from the lower side, and the shape of the upper side of the support shaft support position of this support member is such that the gear on the upper casing side is perpendicular to the opening / closing axis and horizontal. And the amount of this movement is perpendicular to the opening / closing axis of the addendum width of the facing portions of both gears during the closing operation of the upper housing, and the horizontal component dimension. It is getting bigger.

[Action]

When the upper casing is closed with respect to the lower casing, the gear on the upper casing side that moves downward together with the lower casing is supported by the support shaft support portion of the support member while being engaged with the gear on the lower casing side. Then, at this time, if the tooth top surface of the gear on the upper housing side abuts on the tooth surface of the gear on the lower housing side, the gear on the upper housing side moves along this abutting tooth surface to move the tooth tip. The surfaces are disengaged from each other, and the gear on the upper casing side is supported by the support shaft supporting portion of the support member while being engaged with the gear on the lower casing side.

[Embodiment] A first embodiment of the present invention will be described with reference to FIGS. 1 to 4. It should be noted that this embodiment and a second embodiment to be described later will be described in the case of being applied to the image forming apparatus shown in FIGS.

The drive gear 9 arranged on the lower housing 2 side is rotatably fixed to the lower housing 2. On the other hand, the driven gear 8 supported on the upper housing 1 side is provided with some play in a direction perpendicular to the upper housing 1 and is spring-biased downward.

That is, the driven gear 8 is provided in the process cartridge 3 as shown in FIGS. The process cartridge 3 is supported with respect to the upper casing 1 with some play in the direction perpendicular to the axis of the driven gear 8 whose axis is parallel to the opening / closing axis of the upper casing 1. And the frame 19 of the process cartridge 3 is attached by the spring 19 provided in the upper casing 1 with the upper casing 1 closed.
By pushing the side downward, the driven gear 8 is spring-biased downward together with the process cartridge 3.

Reference numeral 10 is a support member for supporting the support shaft 8a of the driven gear 8 at a predetermined position, that is, at a position where the driven gear 8 is properly engaged with the drive gear 9 by moving the upper casing 1 downward. It is fixed to the case side. The support member 10 is provided with a V groove 11 for supporting the support shaft 8a of the driven gear 8 at a predetermined position, and the upper side of the V groove 11 is a parallel groove 12 having a width W wider than the diameter d of the support shaft 8a. It is connected to. This parallel groove 12 and spindle 8a
As shown in Fig. 4, the play size A on one side of
In the relationship with the component dimension B ′ in the direction perpendicular to the opening / closing axis of the upper casing having the tooth tip width B when the tooth tips of 8 and 9 contact, A
≧ B ′.

In the above structure, when the upper casing 1 is closed with respect to the lower casing 2, the driven gear 8 moves downward together with the upper casing 1 and the supporting shaft 8a of the driven gear 8 is fitted into the parallel groove 12 of the supporting member 10. To do.
At the same time, the addendum of the driven gear 8 and the addendum of the drive gear 9 on the lower housing 1 side engage with each other. At this time, the fourth
As shown in the drawing, when the tooth tops do not engage with each other and the tooth top surfaces abut each other, the driven gear 8 can move laterally by the play dimension A with respect to the parallel groove 12, so that the driven gear 8 is driven in this state. When the gear 8 is biased downward by the spring, the driven gear 8 tilts along the inclination of the contact surfaces of the tooth tips and moves downward smoothly until the tooth tips of the driven gear 8 are engaged with each other. In this state, the support shaft 8a of the driven gear 8 fits into the V groove 11 of the support member 10 and is positioned and supported.

Next, a second embodiment will be described with reference to FIGS.

In FIG. 2, the support groove 13 of the support member 10 'for positioning and supporting the support shaft 8a of the driven gear 8 is inclined upward from the support position and toward the drive gear 9 at a clearance angle β. The upper portion of the groove 13 is opened upward.

FIG. 3 shows another aspect of the second embodiment, in which the side wall of the drive groove 9'above the support position of the support groove 13 'is inclined by the clearance angle .beta. Wide upper opening.

In the above structure, the driven gear 8 moves downward to support the supporting shaft.
When the tooth tip of the driven gear 8 is not engaged with the drive gear 9 but abuts against the tooth tip of the driven gear 8 when the 8a is fitted in the bearing grooves 13, 13 ', the support shaft 8a is supported by the supporting groove 13, Moving downward along the clearance angle β of 13 ′ while moving away from the drive gear 9,
Due to this movement, the tooth tips of both gears 8 and 9 are smoothly engaged.

[Effect of device]

According to the present invention, the gear supported on the lower housing side is the drive side gear, and the gear supported on the upper housing side is the driven gear. The driven gear can be smoothly engaged with the drive gear, and the driven gear can be supported on the lower housing side through the support member without any misalignment in the meshed state with the drive gear. When the gear coupling device is used in a process cartridge type image forming apparatus without causing vibration during meshing, it is possible to prevent the occurrence of image unevenness due to the pitch variation of the gear of the gear coupling device. further,
The configuration capable of obtaining the above-described effects can be made extremely simple without increasing the number of parts.

[Brief description of drawings]

FIG. 1 is a schematic configuration explanatory view of a main part showing a first embodiment of the present invention, and FIGS. 2 and 3 are schematic views of a main part showing different aspects of the second embodiment of the present invention. 4 is an enlarged explanatory view showing a state in which the tooth crests are in contact with each other.
5 and 6 are schematic vertical sectional views of the image forming apparatus. FIG. 5 shows a state in which the upper casing is closed, and FIG. 6 shows a state in which the upper casing is opened. FIG. 7, FIG. 8 and FIG. 9 are explanatory views showing an example of arrangement of the fixed gear and the movable gear. 1 is an upper housing, 2 is a lower housing, 8 is a driven gear, 8a is a support shaft, 9 is a drive gear, and 10 is a support member.

Claims (1)

(57) [Scope of utility model registration request] 1. A gear rotatably fixedly supported by a lower housing, and an upper housing which can be opened and closed with respect to the lower housing around an opening / closing axis parallel to the axis of the gear of the lower housing. In a gear coupling device that is provided on the body and that engages with the gear on the lower housing side by the closing operation of the upper housing, the gear on the upper housing side is attached to the opening / closing axis of the upper housing. A support member that supports the shaft of the gear on the upper housing side in a state in which both gears are properly engaged with each other is provided from the upper side while providing play in the right angle direction and spring biasing downward. It is provided on the lower casing side so as to be detachable and supported from the lower side, and the shape of the upper side of the support shaft support position of this support member is such that the gear on the upper casing side is perpendicular to the opening / closing axis. Direction and horizontal shape, and the amount of Gear connecting apparatus characterized by in the direction perpendicular to the opening axis of the tip width of the opposing portions of both gears during the closing operation of the upper housing, and was made to be larger than the horizontal component dimensions.