JPH05126136A - Roller support device and roller - Google Patents

Abstract

PURPOSE:To provide a roller supporting device, with which an initial torque as well as a torque in durability will not be increased. CONSTITUTION:The opening width of an opening end part of a casing 1 having a U-shaped groove part is controlled by a stopper 11 formed on a pressure bearing supporting plate 9. Even when a pair of rollers supported by the side of the casing 1 and by the side of the pressure bearing supporting plate 9, are pressurized by a pressure means, the opening end part will not be narrowed, and the opening width is maintained at a predetermined value (a).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supporting device and a roller for a paper carrying roller used in an LBP (laser beam printer), a copying machine, a facsimile or the like.

[0002]

2. Description of the Related Art As shown in FIG. 16, a supporting device for a paper conveying roller in a conventional copying machine or the like has a U-shaped bearing 4 fitted in a U-shaped casing 1 which is a bearing support.
The roller 2 is fitted to the roller. The reason why the bearing is U-shaped in this way is mainly because the assemblability is improved.
Since bearings such as fixing rollers must slide on the aluminum shaft at high temperatures, it is necessary to use very expensive materials such as PPS and PBT bases. By making them U-shaped, the material is reduced and the cost is reduced. It is also to suppress.

As the bearings for the fixing roller and the like, round ball bearings and slide bearings are also used.
Materials based on PPS and PBT are also used for these materials. These are because PPS or PBT-based materials have self-lubricating properties, and wear particles of these materials are transferred to the surface of the roller, whereby good sliding can be obtained. Therefore,
In order to secure the generation of wear particles for a long period of time, it is necessary to reduce the surface roughness of the sliding surface on the roller side to suppress the wear on the sliding surface on the bearing side to some extent. It is managed to a certain degree.

The numerical value of 3.2S indicates the degree of finishing, meaning that the range of surface roughness is Rmax = 3.2 μm or less, and generally finishing is performed at about Rmax = 3.0 μm (FIG. 17). reference). In addition, the surface roughness here refers to the third peak from the highest convex portion and the third valley from the deepest convex portion of the straight line parallel to the average line of the part where the surface is extracted by the reference length. This is a representation of this interval, which is based on the JIS surface roughness B0601 standard.

[0005]

However, when the U-shaped bearing is used as in the above-mentioned conventional example, the casing 1 for receiving the bearing 4 is molded and the size of the bearing fitting portion of the casing 1 is small. In the case of being deformed in the direction of tightening by the force of the pressure spring, that is, in the direction of tightening the bearing 4 as shown in FIG. There was a problem that it became very unstable.

Further, even when the round bearing is used, there is a problem that the bearing sliding torque of the roller does not exhibit the original performance of the bearing due to the surface roughness of the roller.

That is, since the paper passing surface of the fixing roller is finished by applying Teflon and polishing the surface, the bearing sliding surface of the fixing roller is also polished at the same time, and as a result, the surface roughness of the bearing sliding surface is reduced. It was sometimes finished to about Rmax = 1.0 μm (see FIG. 19). Further, recently, as a low-cost fixing roller, a roller having an anodizing treatment on the roller surface and a PFA tube bonded to the toner fixing surface has been used, but this roller becomes very hard due to the anodizing treatment. There is. When such a roller is used, for example, when the friction coefficient of the bearing is about 0.1 to 0.15, the sliding torque of the fixing roller is supposed to be about 1 kgf · cm, but in reality, it is 1 A torque of 5 times to 2 times or more is generated, and as shown in FIGS. 20 and 21, not only the initial torque is large, but also the sliding torque in durability is not stable. This is because the surface roughness of the bearing sliding surface of the roller is Rmax.
= 2 μm or less, wear powder of the bearing material is less likely to be generated, and the surface anodized, that is, anodized is very hard, so the surface roughness maintains the initial roughness due to durability, and It is difficult for the abrasion powder to enter, resulting in an increase in torque.

An object of the present invention is to solve the above problems and to provide a roller supporting device and a roller which do not increase the initial torque and the torque in durability.

[0009]

According to the present invention, the above-mentioned problems are as follows. First, regarding a roller supporting device, a bearing having a U-shaped groove portion, into which the roller is fitted, or a roller in the groove portion is provided. A bearing support into which the bearing is fitted, a roller support that supports the bearing or a roller that is disposed so as to face the roller supported on the bearing support side, the bearing or the bearing support side or the roller support side A roller supporting device for pressing at least one of the rollers so as to press the rollers against each other. An opening width regulating member for regulating the width of the opening end of the U-shaped groove of the bearing or the bearing support. It is achieved by having Regarding the roller, in the roller whose both ends are supported by the bearing having self-lubricating property,
The bearing sliding surface of the roller has a surface roughness Rmax = 3 μm.
It is achieved by being set to ˜8 μm.

[0010]

According to the present invention, the roller is supported by the bearing having the U-shaped groove portion, or the bearing supporting the roller is fitted to the bearing support, and the other roller is supported by the roller support so as to face the roller. To form a roller pair and press both rollers from the bearing or at least one of the bearing support side and the roller support side by a pressing means, the opening width regulating member is U-shaped in the bearing or the bearing support. Since the width of the opening of the groove is regulated to a predetermined width, the width of the opening of the U-shaped groove is prevented from being narrowed by the pressing force of the pressing means. As a result, the bearing or the bearing support does not tighten the roller or the bearing more than necessary, and an increase in the sliding torque of the roller is prevented. Further, the surface roughness of the bearing sliding surface of the roller is Rmax = 3 μm
Since it is set to ˜8 μm, when both ends of the roller are supported by self-lubricating bearings, an appropriate amount of friction powder is generated from the bearings and the friction powder is reliably retained on the roller surface. As a result, the sliding torque between the roller and the bearing can be stably maintained at a low value both in the initial stage and during durability.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First to fifth embodiments of the present invention will be described with reference to the drawings.

<First Embodiment> First, a first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a diagram showing a schematic configuration of the apparatus of the present embodiment. In FIG. 1, reference numeral 1 denotes a casing (bearing support) which is a main frame of a fixing device, and a U-shaped groove portion which is open in one direction is formed. There is. A fixing roller 2 having a halogen heater 3 therein is attached to the casing 1 via a fixing roller bearing 4 having a U-shaped groove portion which is open in one direction like the casing. The surface temperature of the fixing roller 2 is set to a predetermined temperature by turning on and off the halogen heater 3 while detecting it with a thermistor (not shown).

A pressure roller 6 having a shaft 5 is arranged above the fixing roller 2 so as to be pressed against the fixing roller 2 by a roller support. The roller support includes a pressure bearing 7 that supports the shaft 5 of the pressure roller 6, and a pressure bearing support plate 9 that supports the pressure bearing 7.
The pressure bearing 7 is biased by a pressure spring 8 as a pressure means to keep the contact pressure of the pressure roller 6 against the fixing roller 2 at a predetermined value. The end portion of the pressure bearing support plate 9 is engaged with the support shaft 10 of the casing 1 so as to be openable and closable with respect to the casing 1, and the fixing roller 2 and the pressure roller 6 in the closed state. It is designed to form a roller pair.

As shown in FIG. 2, the pressure bearing support plate 9 is provided with a stopper 11 which is an opening width regulating member which fits into the open portion of the casing 1. The stopper 11 serves as an open portion. The width of the open portion in the radial direction is kept at the design value a by abutting on both side wall surfaces.

In the apparatus of the present embodiment as described above, as shown in FIG. 3, first, the fixing roller bearing 4 is fitted into the casing 1, and then the fixing roller 2 is fitted therein. Then, as shown in FIG. 4, the pressure bearing 7 and the pressure spring 8 are temporarily assembled to the pressure bearing support plate 9, and one of the support plates 9 is engaged with the support shaft 10 to press the pressure roller 6. Fit into the bearing 7. After that, the support plate 9 is rotated around the support shaft 10 to screw the support plate 9 to the casing 1 as shown in FIG. Then, the stopper 11 enters the open portion of the casing 1 and abuts against both wall surfaces of the open portion to prevent the deformation of the casing 1.

Therefore, the U-shaped fixing roller bearing 4
However, since it is not tightened by the casing 1, the sliding torque does not increase as shown in FIG. 6, and good roller support can be performed.

<Second Embodiment> Next, a second embodiment of the present invention will be described with reference to FIG. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as shown in FIG.
1 is configured to have only one side, and the side without the stopper is different from the first embodiment in that the projection 12 provided on the casing 1 and the hole of the pressure bearing support plate 9 are fitted together. In this way, even if the stopper 11 has only one side, the same effect as that of the first embodiment can be achieved.

<Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted.
The present embodiment is an example in which the present invention is applied to the case where the bearing 7'is directly pressed by the spring 8.

When the bearing 7'having a U-shaped groove is directly pressed by the spring 8 as shown in FIG. 22, the bearing 7'is easily deformed in the direction of the arrow. Therefore, in the present embodiment, as shown in FIG. 8, a stopper 13 serving as an opening width regulating member is fitted into the bearing 7 '. As a result, the deformation of the bearing 7'is prevented and the sliding torque is not increased. Further, according to the present embodiment, the stopper 13 also serves as a lid, which has an effect of preventing foreign matter from entering the inside of the bearing 7 '.

<Fourth Embodiment> Next, a fourth embodiment of the present invention will be described with reference to FIG. The same parts as those of the first embodiment are designated by the same reference numerals and the description thereof will be omitted. The present embodiment is an example in which the present invention is applied to the case where the fixing roller bearing is a round bearing 14 as shown in FIG.

As described above, even when the round bearing 14 is used, the stopper 11 prevents the casing 1 from being deformed, and the deformation of the bearing does not increase the sliding torque.

<Fifth Embodiment> Next, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 10 is a view showing the fixing device of this embodiment, and in FIG. 10, reference numeral 15 is a fixing roller. The surface of the fixing roller 15 is a PFA tube 16
Are adhered and are supported by round shafts 17 at both ends. A gear 18 having a retaining member 19 is attached to one end of the fixing roller 15 and is rotatable by a drive source (not shown). Further, the halogen heater 2 is provided inside the fixing roller 15.
0 is provided to heat the surface of the fixing roller 15 to a predetermined temperature.

A pressure roller 21 is supported by a bearing 22 below the fixing roller 15 and a pressure spring 23.
Is pressurized by. In this embodiment, the total pressure by the pressure spring 23 is 7 kg.

The bearing sliding portion of the fixing roller 15 has a surface roughness of Rmax = 3 to 8 μm. The surface roughness is processed so as to fall within the above range by adjusting the roller rotation speed and the bite feed speed during roller cutting. It may also be roughened by blasting or sanding. Further, when the Teflon surface is polished and finished as in the conventional case, it is necessary to polish only the Teflon surface so that the bearing sliding surface maintains the above surface roughness.

Next, the sliding torque of the fixing roller in the above structure is shown in FIGS. 11 to 13. 11 and 12
Is the initial torque when the surface roughness is Rmax = 3.0, 6.0, 8.0 μm for aluminum and alumite rollers (these surface roughness values are shown in FIGS. 17, 14 and 15, respectively). See). The horizontal axis represents the surface temperature of the fixing roller, and the vertical axis represents the sliding torque of the fixing roller. As is clear from the figure, the rougher the surface roughness, the smaller the torque. This is because the actual contact area between the roller surface and the bearing is smaller as the surface roughness is smaller.If the actual contact area is smaller, the shearing force generated by adhesion on the contact surface will be smaller and the resulting frictional force will be smaller. Because it will be. ． Next, FIG. 13 shows changes in torque during durability. The horizontal axis shows the durability time, and the vertical axis shows the sliding torque of the fixing roller. Bearings for aluminum shafts are designed to exhibit excellent sliding characteristics by transferring wear powder to the surface of the mating shaft to form a lubricating film. Is stable.

In the present embodiment, as shown in FIG. 13, it can be seen that the sliding torque decreases as the durability advances regardless of the surface roughness of the roller, whether aluminum or alumite.

It should be noted that if the surface roughness of the roller-side bearing sliding surface is rough, the bearing-side sliding surface is likely to wear, but in this embodiment, the wear is 20 to 30 μm even after endurance, which is a practical problem. Absent.

In the present invention, the alumite roller is more effective than the aluminum roller. This is because in the case of an aluminum roller, the sliding surface is easily roughened due to durability because aluminum is soft, but the anodized surface is very hard and the initial surface roughness is maintained even when sliding on the bearing.

[0030]

As described above, according to the present invention,
Since the width of the opening end of the U-shaped groove in the bearing or the bearing support is restricted by the opening width restricting member, even when the roller pair is formed together with the roller support and pressure is applied by the pressing means, U The width of the V-shaped groove is not narrowed, and the sliding torque of the roller is not increased even at the beginning of use or during durable use. Further, since the U-shaped bearing is used, it is possible to improve the assembling property and reduce the cost by reducing the material even when the bearing is formed of an effective material.

The surface roughness of the bearing sliding surface of the roller is R
Since max = 3 to 8 μm is set, stable sliding characteristics can be obtained from the initial stage of durability. Further, the toner fixing surface of the roller can be applied to the roller to which the PFA tube is adhered by anodizing the surface, and the cost can be reduced. Further, since the surface roughness is obtained by controlling the roller rotation speed and the bite feed speed during the roller cutting process, it is possible to stably obtain the predetermined surface roughness without increasing the cost.

[Brief description of drawings]

FIG. 1 is a front view showing a schematic configuration of a first embodiment device of the present invention.

FIG. 2 is a perspective view showing a schematic configuration of a bearing support body and an opening width regulating member of the apparatus shown in FIG.

FIG. 3 is a diagram illustrating a method of mounting a bearing and a roller on the bearing support of the apparatus of FIG.

FIG. 4 is a diagram illustrating a method of mounting a pressure roller on a roller support of the apparatus of FIG.

5 is a diagram illustrating a method of combining a roller support and a bearing support of the apparatus of FIG.

FIG. 6 is a diagram comparing a roller sliding torque of the apparatus of FIG. 1 with a conventional roller sliding torque.

FIG. 7 is a front view showing a schematic configuration of a second embodiment device of the present invention.

FIG. 8 is a front view showing a schematic configuration of a third embodiment device of the present invention.

FIG. 9 is a front view showing a schematic configuration of a fourth embodiment device of the present invention.

FIG. 10 is a side view showing a schematic configuration of a fifth embodiment device of the present invention.

11 is a diagram showing a sliding torque with respect to a roller surface temperature when an aluminum roller is used as a fixing roller of the apparatus shown in FIG.

12 is a diagram showing a sliding torque with respect to a roller surface temperature when an alumite roller is used as a fixing roller of the apparatus shown in FIG.

13 is a diagram showing a sliding torque during durable use of the fixing roller of the apparatus of FIG.

14 is a diagram showing the surface roughness (Rmax = 6 μm) of the fixing roller in the apparatus shown in FIG.

15 is a diagram showing the surface roughness (Rmax = 8 μm) of the fixing roller in the apparatus shown in FIG.

FIG. 16 is a front view showing a schematic configuration of a conventional device.

17 is a diagram showing the surface roughness (Rmax = 3 μm) of the fixing roller in the conventional device and the device of FIG.

FIG. 18 is a diagram for explaining the deformation of the bearing support of the conventional device.

FIG. 19 shows the surface roughness (Rma) of the fixing roller of the conventional example device.
It is a figure explaining x = 1 micrometer.

FIG. 20 is a diagram showing a sliding torque with respect to a roller surface temperature of a fixing roller of a conventional example device.

FIG. 21 is a diagram showing a sliding torque during durable use of a fixing roller of a conventional device.

FIG. 22 is a diagram for explaining deformation of a bearing in a conventional roller supporting device that directly pressurizes a U-shaped bearing.

[Explanation of symbols]

Reference Signs List 1 casing (bearing support having U-shaped groove) 2 fixing roller (roller supported on bearing supporting side) 4 bearing (bearing having U-shaped groove) 6 pressure roller (roller supported on roller supporting side) 7 Pressure bearing (roller support) 7'bearing (bearing having U-shaped groove) 8 pressure spring (pressurizing means) 9 pressure bearing support plate (roller support) 11, 13 stopper (opening width regulating member) 15 Fixing roller (bearing sliding surface has surface roughness Rmax = 3
Roller set to 8 μm) 17 bearing (bearing having self-lubricating property)

Claims (7)

[Claims] 1. A bearing having a U-shaped groove portion, in which a roller is fitted in the groove portion, or a bearing support body in which a roller bearing is fitted in the groove portion, and a bearing supported on the bearing or the bearing support body side, are opposed to each other. A roller supporting member for supporting the roller arranged so as to perform pressing, and a pressurizing means for pressurizing the respective rollers from at least one of the bearing or the bearing supporting member side or the roller supporting member side so as to press the rollers against each other. A roller supporting device, wherein the supporting device has an opening width regulating member that regulates a width of an opening end of the U-shaped groove of the bearing or the bearing support. 2. The roller support device according to claim 1, wherein the opening width regulating member is formed so as to abut on at least one inner wall in the width direction of the opening end of the U-shaped groove. 3. The roller support device according to claim 1, wherein the bearing fitted to the bearing support having the U-shaped groove is a U-shaped bearing. 4. The roller supporting device according to claim 1, wherein the opening width regulating member is a lid that fits into an opening end of the U-shaped bearing. 5. A roller having both ends rotatably supported by a self-lubricating bearing, wherein a bearing sliding surface of the roller has a surface roughness of Rmax = 3 μm to 8 μm. roller. 6. The roller according to claim 5, wherein the roller surface is anodized. 7. The roller according to claim 5, wherein the surface roughness is set to a desired value by setting the roller rotation speed and the tool feed speed at the time of cutting the roller to predetermined values.