JPH06109082A - Drive - Google Patents

Abstract

(57) [Abstract] [Purpose] It is an object of the present invention to provide a drive device capable of pressing the thrust backlash of a gear with a uniform force independent of load. [Structure] In a series of gear trains for transmitting driving force, 1
A mechanism for urging the gears in the thrust direction by an elastic member is added to one or more gears. [Effect] Vibration and rotation unevenness of the high-speed rotation gear can be suppressed to a low level, backlash can be reduced, and noise during a light load, start-up, and stop can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving device, and more particularly to a driving device for a copying machine, a printer, a facsimile, a printing machine and the like.

[0002]

2. Description of the Related Art A drive unit in a conventional laser beam printer has, for example, a structure as shown in FIG.

In FIG. 4, reference numeral 1 denotes a drive side plate for supporting a motor, a shaft and gears which will be described later, and a shaft 2 is caulked to the drive side plate 1, and the shaft 2 is connected to the gears 31, 32 and 3.
The gear train 3 is formed by inserting the gear trains 3 and 34. Further, 4 is a motor which is a drive source, and the driving force of the motor 4 is applied to the gear train 3
Thus, the final stage gear 34 drives the gear 52 that is coaxial with the roller 51 that conveys the sheet.

The drive unit shown in FIG. 4 is attached to a body frame (not shown) so that the gear train 3 is sandwiched. The gap formed between the main body frame (not shown) and the driving side plate 1 is made slightly larger than the thickness of the gear.
The gear has rattle in the thrust direction and can move freely within this range.

[0005]

However, the above-mentioned conventional example has the following problems with respect to noise and uneven rotation.

[0006] First, there is uneven play in the thrust direction,
Contributes significantly to noise. In other words, this is particularly noticeable at high rotational speeds, and some motors are equipped with springs that urge the shaft in one direction to prevent thrust by the shaft and pinion. Is known. Regarding gears, it is common to use tighter dimensional tolerances to hold back or to use helical gears.
However, at light load, even the helical gear does not exert the biasing effect.

Secondly, the fact that no restraining force acts on the gear may cause noise. In particular, there are impact sounds at the time of starting and stopping and rattling sounds at the time of light load. As described above, even if the helical gear is used, the effect is less likely to occur because the biasing effect is small at light load. If the torsion angle is increased to increase the biasing force, the biasing force at high load is too strong. If the amount of change in load is large, the helical gear cannot exert its effect, but rather has a drawback.

The present invention is intended to solve the above problems. That is, an object of the present invention is to provide a drive device capable of pressing the thrust backlash of a gear with a uniform force independent of load.

[0009]

In order to achieve the above object, the present invention provides one or more gears in a series of gear trains for transmitting a driving force in the thrust direction by elastic members. It is assumed that a mechanism for energizing is added.

[0010]

According to the present invention, one or more gears in a series of gear trains are provided with a mechanism for biasing them in the thrust direction using elastic members. Thrust is suppressed by.

[0011]

FIG. 1 shows a first embodiment of the present invention.

In FIG. 1, the fact that the gear is engaged with the shaft crimped to the drive side plate is the same as in the conventional example shown in FIG. The represented sectional view is shown.

In FIG. 1, reference numeral 1 denotes a drive side plate made of a metal plate which is attached to the main body frame 9 by screws and constitutes one wall surface for sandwiching the gear. 11 is a shaft 21, 22, 2
Reference numerals 3 and 24 denote drive sub-side plates made of sheet metal that are swaged, and are on the side opposite to the gear with respect to the drive-side plate 1. Drive sub side plate 11
The shaft which has been swaged to penetrate the hole on the drive side plate and the hole on the other drive sub side plate 12 made of sheet metal and extends into the hole of the main body frame 9.

The gears 31, 32, 33, 34 are provided on the shaft 21,
It is sandwiched between the drive side plate 1 and the drive sub-side plate 12 so as to be engaged with 22, 23 and 24. Two drive sub side plates 11
And 12 are attracted to each other by the force of the springs 61 and 62, and this force presses the gear in the thrust direction. Among the gears pressed by the side plates 11 and 12 in the drive sub, the thrust size of the gear is slightly larger in the most downstream one (not shown), and the most downstream gear supports the force of the springs 61 and 62 and drives one side plate 1. And the distance between the drive sub side plate 12 is defined.

The driving force generated by the motor 4 is the pinion 4
It is transmitted to the gears 31 and 32 and the gears 33 and 34 via 4 and reaches the drive unit final end gear (not shown). As in the conventional example, the final gear is transmitted to a gear coaxial with the roller and the like.

In this embodiment, there are three final gears. These three final gears are the drive sub side plates 11 and 12
Is further urged to the drive side plate 1, is urged to the drive side plate 1 from the thrust sliding surface, and receives a frictional force from the thrust sliding surface. Therefore, even if the roller or the like to be driven has a light load, the rattling noise due to backlash is suppressed low.

Further, in this structure, the shafts 21, 22, 2 which receive the impact of the meshing of the motor 4 as the oscillation source and the gears.
3 and 24 are attached to the drive sub side plate 11, and the main body and the drive side screwed are only pressed by the springs 61 and 62.

Therefore, it is in a floating state in which the vibrations of these oscillation sources are not directly transmitted to the main body.

Positional accuracy of each gear including the motor in the drive unit is ensured in the drive sub side plate. The shaft of the gear at the final end (not shown) is dimensioned to engage when the tip of the gear jumps into the main body, and this positioning provides positional accuracy with respect to the gear coaxial with the roller and the like. In addition, the gear at the final end and the gear coaxial with the roller and the like have a large module and a large latitude for displacement.

FIG. 2 shows a second embodiment of the present invention.

The second embodiment is an example in which the present invention is applied to the drive portion shown in the conventional example, and the point different from the first embodiment described above is that a thrust biasing force is applied to each gear. . Therefore, the same parts as those in the conventional example are designated by the same reference numerals, and the description of those parts will be omitted.

Reference numeral 6 denotes a pressure unit which is engaged with the shaft 2 and is sandwiched between a gear and a body frame (not shown) to urge the gear toward the drive side plate 1. The pressure unit is composed of bushes 63, 64 made of a resin material having good slidability and a compression spring 65. The bush 64 contacts the thrust sliding surface of the gear, and the bush 63 contacts the sliding surface of the body frame.

FIG. 3 is an enlarged view of the pressure unit 6. In this embodiment, each pressurizing unit 6 urges each gear.

Since a uniform biasing force is applied to each gear regardless of the load, backlash occurs when the power source of the motor, which is the drive source, is turned off (especially remarkable for stepping motors). Are held to a minimum by frictional resistance.

Therefore, the impact at the time of starting and stopping the motor can be suppressed low. It is possible to suppress noise and vibration due to the thrust backlash of the high-speed rotating gear near the motor pinion that rotates at high speed.

[0026]

As described above, according to the present invention,
Since one or more gears in the series of gear trains are provided with a mechanism for biasing them in the thrust direction using an elastic member,
The thrust rattle is pressed by a constant load that does not depend on the driving load. Therefore, vibration and rotation unevenness of the high-speed rotation gear can be suppressed to a low level, backlash can be reduced, and noise during light load, start-up, and stop can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is a perspective view showing a second embodiment of the present invention.

FIG. 3 is an enlarged sectional view showing the pressure unit of FIG.

FIG. 4 is a perspective view showing an example of a conventional technique.

[Explanation of symbols]

1 ... Drive side plates 21, 22, 2
3, 24 ... Shaft 31, 32, 33, 34 ... Gear 6 ... Pressurizing unit 61, 62 ... Spring

Claims (1)

[Claims] 1. A drive device, wherein in a series of gear trains for transmitting a driving force, a mechanism for urging the gear in the thrust direction by an elastic member is provided to one or more gears.