JP3283189B2 - Driving force transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force in which a joint gear is engaged with a driven member to transmit a driving force of a motor or the like to the driven member, and the joint gear can move in a direction of contacting and separating from the driven member. It relates to a transmission device.

[0002]

2. Description of the Related Art As a driving force transmitting device for transmitting a driving force of a motor or the like to a driven member, various types capable of absorbing a change in an interval between the driven member and the driven member have been adopted.

For example, as shown in Japanese Utility Model Laid-Open No. 7-23742 and Japanese Utility Model Laid-open No. 7-9844, in a transmission device for transmitting a rotational driving force to a copy paper lifting shaft of a paper feed tray of a copying machine, When the copy paper is refilled, the paper feed tray is pulled out from the copying machine main body, and after the copy paper is refilled, the paper feed tray is pushed in and loaded into the copier main body. By this pushing operation, the end of the copy paper lifting shaft pivotally supported in the paper feed tray is pressed coaxially to the joint in the driving force transmission device of the copy paper main body. It is necessary that the joint distal end engaging portion engages with the distal end of the copy paper lifting shaft and can move in the axial direction while being movable in the loading direction of the paper feed tray. Therefore, the joint for transmitting the motor driving force to the copy paper lifting shaft must be able to retreat in the axial direction against the urging force and transmit the motor driving force.

[0004] Referring to FIG. 3, the output rotation of the motor 106 attached to the assembled upper case 102 and lower case 104 is transmitted to an output shaft 110 via a transmission gear 108. A joint 112 is slidably fitted to the tip of the output shaft 110, and is pushed toward the tip of the output shaft 110 by the urging force of a compression coil spring 114. For this reason, loading operation of the paper feed tray (direction of arrow A)
The copy paper lifting shaft (not shown) is connected to the output shaft 110.
To push the joint 112 against the compression coil spring 114 and
Engage with 2.

If the unevenness between the copy paper lifting shaft and the joint at the leading end of the joint does not engage due to the rotational phase difference, the joint temporarily retreats against the urging force, and then the motor rotates. Thereby, the joint can be retracted so that the concave and convex can be engaged and engaged.

[0006]

Such a driving force transmitting device includes an output shaft 110 which rotates by receiving a driving force, a joint 112 slidably attached to the output shaft 110, and an output shaft of the joint 112. Teeth washer 116 from 110, joint 112
Various components such as a compression coil spring 114 for urging the protruding member in a direction protruding from the output shaft 110 are required.

An object of the present invention is to provide a driving force transmission device capable of reducing the number of parts in consideration of the above fact.

[0008]

According to a first aspect of the present invention, there is provided a driving force transmitting device including a pair of opposing walls, and a support shaft protruding from the other opposing wall toward a through hole formed in one opposing wall. A case, a transmission gear rotatably supported in the case in a state parallel to the support shaft and receiving a driving force, and a shaft to the support shaft;
The transmission gear is supported and meshes with the transmission gear.
Provided movably along the support shaft in a state, and
A joint gear engagement means to the driven member is formed at the tip portion protruding from the through hole, the permeability before Symbol Case
It biases the joint gear to the projecting direction through the hole transmural
Biasing means is characterized by having a stopper for restricting the movement amount of the support projecting direction along the axis of the joint gear.

In the driving force transmission device having the above structure, the engagement means at the tip of the joint gear is engaged with the driven member. Also, depending on the state of engagement with the driven member, the joint gear is pushed in against the urging force of the urging means while maintaining engagement with the transmission gear during engagement, so that the rotational force from the transmission gear is applied to the joint gear. It is transmitted.

According to a second aspect of the present invention, in the driving force transmitting apparatus according to the first aspect, the stopper is configured such that a periphery of the through- hole of the case abuts on the joint gear, and the joint gear is connected to the joint gear. It is characterized by restricting the protruding direction movement amount.

In the driving force transmission device having the above structure, the stopper for limiting the amount of protrusion of the joint gear from the case is formed by the joint gear and the periphery of the through hole of the case.
The movement amount of the joint gear is limited without using a separate part as the stopper.

[0012] driving force transmission device according to claim 3 is the driving force transmission apparatus according to claim 1 or claim 2, wherein the case has a lower case and upper case, the in the lower case The support shaft is characterized in that the through hole is formed in the upper case.

In the driving force transmission device having the above structure, the lower case and the upper case can be assembled by fitting them together with the joint gear and the urging means interposed therebetween.

[0014]

FIG. 1 is a sectional view of a motor device 10 as a driving force transmitting device according to an embodiment of the present invention. The motor device 10 is generally installed so that FIG. 1 is a plan view, but the installation position is not limited to the state shown in FIG. Also, for convenience of explanation, the upper and lower parts of FIG. 1 will be simply described as upper and lower parts.

As shown in FIG.
The case 12 is composed of two members, that is, a lower case 14 as a case component having walls facing each other and an upper case 16 as a case component. The lower case 14 has a box shape opened upward, and has a bottom 1
4A, a plurality of bearing portions 18, 20, 22 opened upward.
Are formed. Further, a support shaft 24 is formed integrally with the bottom 14A so as to protrude vertically upward from the side of the bearing 22 on the bottom 14A. The support shaft 24 has a cylindrical shape as a whole, has an upper end closed and a lower end opened, and has substantially the same thickness as the lower case 14.

On the other hand, the upper case 16 is formed in a box shape whose opening is substantially downward and the upper wall portion 16A is opposed to the bottom portion 14A. It is fixed. Also, the upper wall 16 of the upper case 16
A is formed with a plurality of bearing portions 26, 28, 30 which are open downward. These bearings 26, 28, 30
The bearing portion 26 is formed coaxially with the bearing portion 18 and the bearing portion 2
8 are formed coaxially with the bearing portion 20,
Are formed coaxially with the bearing portion 20. A circular hole 32 is formed in the upper wall 16A of the upper case 16 as a through hole. The circular hole 32 is formed coaxially with the support shaft 24 and has a large diameter.
2 and project outside the case 12. Further, a thrust receiving portion 34 as a stopper protruding toward the inside of the case 12 is formed at a peripheral portion of the circular hole 32.

A motor 36 is housed inside the case 12 having the above configuration. Although a part of the lower case 14 accommodating the motor 36 is a bulging portion 14B, the motor 36 may be partially exposed to the outside or may be attached to the outside of the case 12. A worm gear 40 is fixed to a drive shaft 38 of the motor 36. This worm gear 40
The first gear 42 is arranged on the side of the first gear 42. In the first gear 42, both ends of a rotary shaft 44 are rotatably supported by bearings 18 and 26. The rotating shaft 44 is formed with a pair of gear portions 46 and 48 having different diameters along the axial direction. The large-diameter gear portion 46 is located below the small-diameter gear portion 48 and is engaged with the worm gear 40.

A second gear 50 is disposed on the side of the first gear 42 opposite to the worm gear 40. In the second gear 50, both ends of a rotating shaft 52 are rotatably supported by bearings 20 and 28. The rotating shaft 52 is formed with a pair of gear portions 54 and 56 having different diameters along the axial direction. The large-diameter gear portion 54 is located above the small-diameter gear portion 56 and is engaged with the gear portion 48 of the first gear 42.

Further, a third gear 58 as a transmission gear is disposed on the side opposite to the first gear 42 of the second gear 50. The third gear 58 is configured such that both ends of the rotating shaft 60
It is rotatably supported to 2, 30. The rotating shaft 6
0 has a pair of gear portions 62 having different diameters along the axial direction,
64 are formed. The large-diameter gear portion 62 is located below the small-diameter gear portion 64 and is engaged with the gear portion 56 of the second gear 50. On the other hand, the gear portion 64 is formed uniformly from the upper end side of the gear portion 62 to the space between the bearing portions 30 and has a longer shaft length (tooth width dimension) than the other gear portions.

An output shaft 70 as a joint gear is arranged on the third gear 58 on the side opposite to the second gear 50. The output shaft 70 has a small-diameter portion 78 on the upper end side and a stepped portion 7.
It has a convex shape in cross section integrated with the large-diameter portion 74 on the lower end side through 0A, and a circular through hole 72 penetrating along the axial direction is formed in the center in the radial direction. The inner diameter of the through-hole 72 is set to be fit into the support shaft 24 of the lower case 14, and the output shaft 70 is rotatably supported by the support shaft 24 by fitting the through-hole 72 into the support shaft 24. In addition, it is slidable along the support shaft 24 in the vertical direction (that is, the axial direction of the support shaft 24). A gear portion 76 is formed on the outer peripheral portion of the large diameter portion 74 on the lower end side of the output shaft 70, and is engaged with the gear portion 64 of the third gear 58. Here, the shaft length (tooth width dimension) of the gear portion 76
Is formed smaller than the gear portion 64 of the third gear 58, and the gear portion 76 maintains the engagement with the gear portion 64 even when the output shaft 70 moves along the support shaft 24.

On the other hand, the small diameter portion 78 on the upper end side of the output shaft 70
Has an outer diameter corresponding to the inner diameter of the circular hole 32, penetrates the circular hole 32 while being supported by the circular hole 32, and protrudes outward from the case 12. The distal end of the small-diameter portion 78 is a joint 80 as an engagement means.
The cylindrical protrusion protruding coaxially with 0 is divided by a plurality of radial cuts 80A (four in this embodiment). The joint part 80 can transmit a rotational force by fitting to a driven member (not shown) of another device installed outside the case 12. That is, the driven member is inserted coaxially with the output shaft 70 in the direction of the arrow A, and the non-circular engaging projection (cross-shaped or-shaped projection as viewed from the axial direction) at the tip enters the cut 80A, and Engage with. In addition, a lightening portion 71 is formed on the output shaft 70 from below,
Although the output shaft 70 has a double cylinder structure connected to each other at the upper end, this lightening structure is not an essential requirement.

A compression coil spring 82 is disposed around the support shaft 24 between the output shaft 70 and the bottom 14A of the lower case 14, and the output shaft 70 is connected to the support shaft 24 by the compression coil spring 82. is biased in a direction away from the bottom portion 14A of the lower case 14 along, pressure to the output shaft 70
The upper end surface 74A of the large-diameter portion 74 of the output shaft 70 is in contact with the thrust receiving portion 34 unless a force against the urging force of the compression coil spring 82 acts.

Although each of the above-mentioned gear portions is a spur gear, other kinds of tooth shapes such as a helical gear can be applied.

Next, the operation of the present embodiment will be described. The motor device 10 is attached to, for example, a paper feed tray loading section of a copying machine main body. Paper tray (not shown)
When loading the tray to the copier main body copy sheet after replenishment to a copy sheet lifting shaft in the tray (not shown) the axial direction of the output shaft 70 shown by the arrow A (i.e., the support shaft 24 (In the axial direction), and the engaging projection at the tip is cut into the engaging projection 80A of the joint portion 80.
Is fitted to Here, since the gear portion 76 of the output shaft 70 is engaged with the gear portion 64 uniformly formed between the bearing portion 30 and the upper end side of the gear portion 62 of the third gear 58, the joint portion 80 Is slidable in the direction of arrow A against the urging force of the compression coil spring 82 to absorb the difference in the loading stroke of the paper feed tray and ensure engagement with the copy paper lifting shaft. Also in this case, the gear 76 and the gear 6
The engagement with 4 has been maintained.

As described above, when the motor 36 is driven in a state where the joint portion 80 is fitted to the driven member, the driving force of the motor 36 is changed from the worm gear 40 to the first gear 42,
The output shaft 70 is transmitted to the gear portion 76 of the output shaft 70 while being reduced through the second gear 50 and the third gear 58, and is supported around the support shaft 24 while the output shaft 70 is supported by the support shaft 24 and the circular hole 32. Rotate. This driving force of the motor 36 is transmitted to the driven member, lifted the copy paper leading end of the paper feed tray copy sheet lifting upper up shaft is rotated in contact with the copy paper take-out roller, and unloading preparation state Become. In this state, if the engaging projection of the copy paper lifting shaft, which is the driven member, does not match the notch 80A of the joint portion 80 due to the variation of the rotation stop position, the output shaft 70 is compressed by the tray loading operation. 82 is deflected and pushed downward from the state shown in the drawing to be in a retracted state. After that, when the joint portion 80 is slightly rotated by the rotational force of the motor 36, the rotational phase difference between the joint portion 80 and the copy paper lifting shaft is eliminated, and the engagement protrusion coincides with the cut 80A.
The output shaft 70 is raised by the urging force of the compression coil spring 82, and the joint 80 is securely engaged with the copy paper lifting shaft.

Here, in the motor device 10, the output shaft 70
A joint portion 80 is formed at the end of the output shaft 70, and the thrust receiving portion 34 of the upper case 16 prevents the output shaft 70 from coming off. Compared to the case where the joint is prevented from being removed by mounting, tooth washer, etc.
The number of parts can be reduced, the number of assembly steps can be reduced, and the cost can be reduced.

In the present embodiment, the output shaft 70 is supported on the outside of the support shaft 24, and the output shaft 70 is integrally formed with the joint portion 80, so that there is no extremely thin portion. , In terms of strength. On the other hand, in the conventional example shown in FIG.
Since both ends have a large diameter with the joint 112 and the gear portion that meshes with the transmission gear 108, the load torque at the intermediate portion of the small-diameter output shaft is large, causing fatigue. Also,
In the conventional example, the bearing that supports the lower end of the output shaft 110 is formed in a part of the lower case 104, so
However, the bias of the compression coil spring 114 (displacement of the coil with respect to the output shaft 110) is also a factor that increases the bend. However, in the above embodiment, the bias is integrated with the lower case 14. Is used as a bearing, the compression coil spring 82
Also around the support shaft 24 without any deviation, the output shaft 70
Verticality is maintained.

In the present embodiment, the retaining means for the output shaft 70 is configured as the thrust receiving portion 34 of the upper case 16. However, for example, as in the motor device 90 shown in FIG. A stopper such as a tooth washer 92 may be fitted to the end of the output shaft 70, and the outer periphery of the stopper may be applied to the inner step 70B of the output shaft 70 to serve as an axial stopper for the output shaft 70.

[0029]

According to the present invention, the number of parts can be reduced and the number of assembling steps can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view of a driving force transmission device according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a modification of the driving force transmission device according to one embodiment of the present invention.

FIG. 3 is a sectional view showing a conventional driving force transmission device.

[Explanation of symbols]

Reference Signs List 10 motor device (driving force transmission device) 12 case 14 lower case 16 lower case 24 support shaft 32 circular hole (through hole ) 34 thrust receiving portion (stopper) 36 motor 58 third gear (transmission gear) 70 output shaft (joint gear) 70A Step (stopper) 80 Joint (engaging means) 82 Compression coil spring (biasing means) 90 Motor device (driving force transmission device)

Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F16H 1/20 B65H 1/14 H02K 7/116

Claims (3)

(57) [Claims] 1. A case having a pair of opposing walls, and a support shaft protruding from the other opposing wall toward a through hole formed in one of the opposing walls; and a shaft in the case parallel to the support shaft. A transmission gear that is supported and rotates by receiving a driving force; and a transmission gear that is supported by the support shaft and meshes with the transmission gear.
To be movable along the support shaft in the engaged state.
Provided, and, the job and the joint gear engagement means to the driven member is formed at the tip portion protruding from the through hole, the projecting direction through transmural said hole from the front Symbol Case
And biasing means urges Intogiya, driving force transmission apparatus characterized by having a stopper for restricting the movement amount of projecting direction along the support shaft of the joint gear. 2. The stopper according to claim 1, wherein the stopper is provided in the through hole of the case.
2. The driving force transmission device according to claim 1, wherein a periphery of the driving gear is in contact with the joint gear to limit a movement amount of the joint gear in a protruding direction. Wherein the case has a lower case and upper case, the support shaft in the lower case, before the upper case
Claim 1 or claim, characterized in that KiToruana is formed
Item 3. The driving force transmission device according to Item 2.