JPH0625707Y2 - Oldham fittings - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an Oldham coupling for transmitting rotation between two parallel shafts.

[Conventional technology]

Recently, in order to facilitate the maintenance of various equipment, one or a plurality of equipment constituting the equipment has been unitized, and a configuration in which this is detachably attached to the equipment main body is actively adopted. Situation.

If there is any rotating body in such a unit,
When the unit is loaded, it is necessary to connect the rotating body to the drive unit on the main body side. The Oldham coupling has been widely used as such a drive connecting means.

Normally, the unit is inserted and removed from the main body with a guide rail etc., but at the time of this insertion and loading, the unit side shaft,
It is difficult to accurately align the respective shaft centers with the drive shaft on the main body side, and it is easy for the shaft centers to shift from each other.

The Oldham coupling is a type of shaft coupling that connects two axes, and is widely used as a device that can tolerate a slight deviation in the shaft center.

FIG. 10 shows an example of an Oldham's joint, which is composed of a drive disk 1, an intermediate transmission disk 2, a driven disk 3, etc., each of which is connected by an uneven joint as shown in the figure.

FIG. 11 shows a configuration example in which an Oldham coupling is used for driving connection of a developing device provided in an image forming apparatus such as an electrophotographic copying machine, a printer or a facsimile as a unit. is there.

A motor 15 provided on the side plate 14 of the image forming apparatus main body
Is a rotary drive source of this device example, and the gear 16 attached to the motor shaft 15a meshes with the gear 11A integrally formed on the drive disk 11 by plastic molding, for example.

A drive disk 11 is rotatably and axially slidably supported on a shaft 17 having one end fixed to the side plate 14, and the shaft 17 also has an intermediate transmission disk 12 as shown in FIG. Are fitted with a relatively large fitting clearance.

The intermediate transmission disc 12 and the drive disc 11 are given a habit of moving to the left on the shaft 17 in FIG. 12 by the compression spring 19, and the movement due to this habit is a retaining ring for preventing the intermediate transmission disc from coming off. Blocked by 20.

The driven disk 13 is integrally fixed to the other shaft 18 arranged in the axial direction of the shaft 17 at this end portion by, for example, a pin or the like. Although the shaft 18 is connected to the developing roller 23 provided in the developing unit 22 in this example, another shaft may be connected to the shaft 18 and the developing roller may be provided on the shaft 18.

As shown in FIG. 13, the drive disc 11 is formed with a joint protrusion 11 a, which engages with the joint recess 12 b of the intermediate transmission disc 12. Further, the driven disk 13 has a joint projection 13a of a suitable shape divided into both sides.
Is formed, which is the joint recess 1 of the intermediate transmission disc 12.
It is adapted to engage with 2c. Note that FIG. 12 is a sectional view of the assembled discs of FIG.

In FIG. 11, the component on the right side including the intermediate transmission disc 12 constitutes the apparatus main body side, and the intermediate transmission disc 1
2 is in a state of being engaged with the drive disk 11 at each joint.

When the developing unit 22 is inserted and loaded into the apparatus main body along a guide rail (not shown), the driven disk 13
The joint protrusion 13a of the joint is the joint recess 1 of the intermediate transmission disk 12.
If it is a good match with 2c, both will engage with each other as it is, and the connection of the unit to the drive unit will be completed.

When the motor 15 rotates in this state, the gear 16
The gear 11A, that is, the drive disk 11 rotates via the. This rotation is transmitted to the driven disc 13 via the intermediate transmission disc 12, and the developing roller 23 is rotated.

Even if the shaft 18 on the unit side slightly deviates from the shaft 17 on the device body side, the deviation is allowed due to the function of the Oldham's joint, and the rotational force from the drive side to the driven side can be smoothly changed. Will be transmitted.

Here, in FIG. 11, when the units are connected, the joint protrusion 13a of the driven disc 13 is not
It is extremely rare to directly engage with the joint recess 12c of the above, and normally, the end face of the joint protrusion 13a (Fig. 13) does not substantially mesh with each other, and the end face of the intermediate transmission disk 12 does not. There are many cases where it hits.

In such a case, the driven disk 13 pushes the intermediate transmission disk 12, the drive disk 11 and the like toward the apparatus main body side against the extension elasticity of the compression spring 19, and the drive disk 11 and the drive disk 11 are driven when the motor 15 is started. Intermediate transmission disk 12
Is rotated integrally with each other, the joint recess 12c of the intermediate transmission disc 12 is moved to the driven disc 13 as the rotation progresses.
When fitted to the joint protrusion 13a, the intermediate transmission disc 12 is moved together with the drive disc 11 by the extension elastic force of the spring 19, so that the joint protrusion 13a and the joint recess 12c are engaged with each other. After that, in this state, the transmission of the rotational force to the developing unit side starts.

Here, the intermediate transmission disc 12 is attached to the shaft 17 with a relatively large fitting clearance in order to perform the eccentric rotational movement due to its unique function as an Oldham's joint. Therefore, for example, as shown in FIG.
After the motor is started, the intermediate transmission disk 12 is
When the rotation position 2b is in the vertical position, the intermediate transmission disk 12 slides by the clearance and falls downward as shown in FIG. That is, the center of rotation of the intermediate transmission disk 12 is displaced below the axis of the shaft 17. Incidentally, FIG. 14 is a partial vertical cross-sectional view of the assembled intermediate transmission disc 12, drive disc 11 and the like shown in FIG.

At such a rotational position of the intermediate transmission disc 12, the joint recess 12c orthogonal to the joint recess 12b is aligned with the joint protrusion 13a of the driven disc 13 as shown in FIG.
When they both try to engage each other, the intermediate transmission disc 1
As shown in FIG. 14, the joint concave portion 12c does not mesh with the joint convex portion 13a of the driven disk 13 because the number 2 is lowered. As a result, the rotation cannot be transmitted from the driving side to the developing unit side.

[Problems to be solved by the device]

In order to prevent the above-mentioned inconvenience, conventionally, the joint protrusion 11a of the drive disc 11 and the intermediate transmission disc 12 are provided.
The friction coefficient of the slip surface of each part with the joint recess 12b is increased so that the intermediate transmission disk 12 does not slide downward. However, in this case, the shaft on the driven side is prevented. 18 generates vibrations and reduces transmission efficiency.

The present invention has been made in view of the above problems, and an object of the present invention is to provide an Oldham coupling that can smoothly and reliably engage the joint portion even if the intermediate transmission disc is eccentrically displaced downward. And

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a drive disk provided on an axis and a driven disk provided on another axis arranged substantially in the axial direction of the axis, between the two disks. An intermediate transmission disc fitted to one of the shafts is provided, and one of the joints of the discs can be freely engaged with and disengaged from the joint of the mating disc. An Oldham coupling for transmitting the rotation of the drive disc to the driven disc side through the intermediate transmission disc, wherein the difference in the widths of the distal end portions of the respective coupling portions to be engaged and disengaged is determined by any one of the above-mentioned intermediate transmission discs. The feature is that the clearance is set to be larger than the fitting clearance for one shaft.

[Action]

In this Oldham joint, the difference in the widths of the tips of the joints that are engaged and disengaged from each other is set to be larger than the fitting clearance with respect to the shaft of the intermediate transmission disk. When they match with each other, they are engaged with each other without being caught.

〔Example〕

Hereinafter, embodiments will be described with reference to the drawings. In addition,
In this description, members having the same functions as those of the conventional example will be designated by the same reference numerals for convenience, and duplicate description of the same parts will be omitted.

In FIG. ₁ , the diameter of the drive side shaft 17 is d ₁ , the diameter of the hole 12d through which the shaft 17 is inserted in the intermediate transmission disk 12 is d ₂ , the recess width of the joint recess 12c is t ₁ , and the driven disk 1 is shown.
The protrusion width of the joint protrusion 13a of No. 3 is t ₂ (see FIG. 13). The portion indicated by F (Fig. 13) in the joint convex portion 13a becomes the slip surface in the eccentric movement of the intermediate transmission disc, whereas the portion indicated by G (Fig. 13) in the joint concave portion 12c is the slip surface. Becomes In FIG. 1, the structure of the main body of the apparatus such as the drive disk and the motor is omitted (the same applies to FIGS. 2 to 4).

Here, the difference between d ₂ and d ₁ is the fitting clearance of the hole 12d with respect to the shaft 17, but when the intermediate transmission disk 12 slides down by this clearance, the joint projection 13a and the joint projection 13a In order to mesh with the recess 12c, the following conditions may be satisfied.

(t ₁ -t ₂ ) ≧ (d ₂ -d ₁ ) ... (1) where (t ₁ -t ₂ ) is the difference in width between the joint recess 12 c and the joint protrusion 13 a. is there. That is, it means the difference in the widths of the tips of the joints of the Oldham joint that are engaged and disengaged from each other. If such a difference is set to be larger than the fitting clearance described above, the two can be engaged with each other even if the intermediate transmission disc 12 is eccentrically displaced downward.

That is, as shown in FIG. 2, the intermediate transmission disk 12
It is sufficient to determine the recess width t ₁ of the joint recess 12c so that the joint recess 12c can be engaged with the joint protrusion 13a even if the clearance is lowered by the above clearance. Such a condition is the above formula (1).

With this configuration, the Oldham joint can be joined without fail, and there is no need to take measures to increase the friction coefficient of the sliding surface, so that there is no concern about the occurrence of vibration.

However, if t ₁ -t ₂ is set too large, uneven wear may occur in the protrusions 13a and the recesses 12c, or vibration may occur on the driven disk 13 side. Should be set. In the experiment, the outer diameter of the drive disc, intermediate transmission disc and driven disc was 20 mm.
At this time, setting t ₁ -t ₂ to 1 mm or less was advantageous because the above-mentioned problems did not occur.

Further, the above-described embodiment can be particularly advantageously adopted when the positional deviation between the shafts 17 and 18 is small.

Next, another embodiment will be described with reference to FIG.

This embodiment is characterized in that the portion indicated by the reference numeral 12c ₁ of the joint concave portion 12c and the portion indicated by the reference numeral 13a ₁ of the joint convex portion 13a are respectively chamfered portions. Here, the maximum width between the double-sided portions 12c ₁ is t ₃ , and the double-sided portion 13 is
Assuming that the minimum width between a ₁ is t ₄ , the following conditions may be set in order to ensure joint coupling.

(t ₃ -t ₄ ) ≧ (d ₂ -d ₁ ) That is, in this case as well, the difference in width (t ₃ -t ₄ ) between the tips of the joints of the Oldham couplings that are disengaged from each other is calculated as The fitting clearance (d ₂ −d ₁ ) of 12 or more is set.

If such conditions are set, as shown in FIG.
The chamfered portions first come into contact with each other, and then the joint convex portion 13a and the joint concave portion 12c are smoothly engaged with each other by the guide action of this portion and the action of the spring 19 (FIG. 11).

In this embodiment, the misalignment of the axes of the shafts 17 and 18 is
Even if it is quite large, the joint connection can be surely made.

As shown in FIG. 5, if the angle θ of the chamfered portion 13a ₁ is set in the range of 30 ° ≦ θ ≦ 70 °, the joint connection can be surely achieved. It will change. When θ <30 °, (t ₃ −t ₁ ) and (t ₂
-t ₄ ), the ease of fitting the convex portion 13a and the concave portion 12c is not so different from the case of FIG. 2, and θ>
If the angle is 70 °, slippage may not occur properly at the double-sided portion.

By the way, in the embodiments described so far, the driven disk 13
The intermediate transmission disc 12 and the intermediate transmission disc 12 are configured such that their joints are engaged and disengaged when the units are connected. As shown in FIG. 6, the driven disc 113 and the intermediate transmission disc 112 are combined with each other. Alternatively, the joint recess 112b of the intermediate transmission disc 112 and the joint protrusion 111a of the drive disc 111 may be engaged and disengaged from each other.

In this example, the intermediate transmission disk 112 is provided toward the shaft 18 on the unit side. In this example, the chamfering method is adopted, but a chamfering method may be omitted.

In addition, as shown in FIG. 7, with respect to the compression spring 19,
This may be provided on the shaft 18 on the unit side, and in this example, the spring 19 and the driven disk 113 may be provided.
Are respectively provided on the shaft 18, and the intermediate transmission disk 112 provided on the shaft 18 in the drawing is replaced by the drive disk 1
11 and 11, may be provided on the shaft 17 of the apparatus main body side. Further, in addition to the spring 19 on the driven disk 113 side, a spring for pushing this to the unit side may be provided on the drive disk 111 side.

In addition to the method of each of the embodiments described above, the combination example shown in FIGS. 8 and 9 can be adopted as the method of combining the joint convex portion and the joint concave portion of the Oldham joint, and in any case, Various combinations can be adopted.

Further, although the developing unit 22 is used as the object to be driven in the embodiments described so far, it may be a cleaning unit or a fixing unit in an image forming apparatus such as a copying machine. The present invention can be applied to a device having a predetermined rotation transmission system.

[Effect of device]

Since the present invention is configured as described above, even if the intermediate transmission disc is eccentrically displaced, the joint coupling between the discs can be reliably performed, and the reliability of this type of performance can be further enhanced. it can. Further, since it is not necessary to take measures such as increasing the friction coefficient of the joint portion, there is no need to worry about vibration.

[Brief description of drawings]

FIG. 1 is a dimensional specification relationship diagram of a driven disc and an intermediate transmission disc for explaining one embodiment of the present invention, and FIG. 2 is a diagram showing a halfway state when a joint between the driven disc and the intermediate transmission disc is connected. The figure is a dimensional specification relationship diagram of a driven disc and an intermediate transmission disc for explaining another embodiment, FIG. 4 is a diagram showing a joint coupling initial state of another embodiment, and FIG. 5 is for explaining an angle of a chamfered portion. FIG. 6, FIG. 6 is a view showing a joint connection initial state of yet another embodiment, FIG. 7 is a view showing a joint connection initial state of yet another embodiment, and FIGS. 8 and 9 are uneven combinations of joint portions. FIG. 10 is a diagram showing each example, FIG. 10 is a principle configuration diagram of an Oldham coupling, FIG. 11 is a unit drive configuration diagram used for explaining a conventional technique, and FIG. 12 is the same as the above unit drive configuration. Cross-sectional view showing the 3 FIG combination configuration perspective view of the disk, FIG. 14 is a longitudinal sectional view of a portion showing a state before a no connection of the Oldham coupling is made. 11, 111 ... Drive disk 12, 112 ... Intermediate transmission disk 13, 113 ... Driven disk 17, 18 ... Shaft t ₁ , t ₂ , t ₃ , t ₄ ... Width

Claims (1)

[Scope of utility model registration request] 1. A shaft mounted on one of the two shafts between a drive disk mounted on the shaft and a driven disk mounted on another shaft disposed substantially in the axial direction of the shaft. The intermediary transmission discs that are combined are provided, and one of the joints of the discs can be engaged with and disengaged from the joint of the disc on the other side.
An Oldham coupling for transmitting to the driven disc side through an intermediate transmission disc, wherein the difference in the widths of the tip portions of the respective coupling parts to be engaged and disengaged is fitted to one of the shafts of the intermediate transmission disc. An Oldham coupling that is set to have a clearance larger than that.