JPH1151051A - Air guide roller with touchdown bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the direct contact of a guide roller and a bearing surface. SOLUTION: A touchdown bearing 4 is fittingly installed on the outer peripheral surface of a shaft 2, and its main body is composed of an inner ring 4a positioned and fixed by the shoulder of the shaft 2, and a fastening nut 6; an outer ring 4b opposing through the inner peripheral surface 1a of a guide roller 1 (the area 1a2) and a touchdown clearance S2 ; and plural balls 4c provided between the inner ring 4a and the outer ring 4b. The size Cr2 of the touchdown clearance S2 is set smaller a specific amount than the size Cr1 of a radial bearing clearance S1 (Cr2<Cr1).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air guide roller for winding and guiding a tape or the like in a tape or film manufacturing process.

[0002]

2. Description of the Related Art A guide roller used in the manufacturing process of tapes and films is required to have high-speed rotation, low torque, and good rotational runout accuracy. It is often used (air guide roller).

[0003] The air guide roller inserts a shaft through the inner peripheral surface of a cylindrical guide roller, and supplies compressed air to a bearing gap between the guide roller and a bearing surface provided on the shaft side, thereby providing a guide. The roller is rotatably supported in a non-contact manner with respect to the bearing surface. A radial air bearing supports the guide roller in a non-contact manner in the radial direction, and a radial air bearing and a thrust air bearing support the guide roller in both the radial and thrust directions.

[0004]

The air guide roller is
Since the load of the guide roller is received by the pressure distribution of the thin air film formed in the bearing gap, the members constituting the hydrostatic air bearing are used in combination with a material having good seizure resistance. However, if an excessive impact load is applied during operation, or if driving is performed for a long time with the supply of compressed air cut off for some reason, the guide rollers may directly contact the bearing surface and seizure may occur. Yes. Also, when handling the product in a state where compressed air is not supplied, such as during product transportation or assembly adjustment, fix the guide roller and shaft with a fixing jig or the like so that the radial bearing surface is not damaged by contact with the guide roller. It had to be fixed firmly. Therefore, the work of packing, transporting, unsealing, and assembling and adjusting the product is complicated. Furthermore, since the material selection of the components of the hydrostatic air bearing is performed with priority given to seizure resistance,
In some cases, processing costs and material costs are increased, and there is room for improvement from the viewpoint of cost reduction.

An object of the present invention is to solve the above-mentioned problems.

[0006]

According to the present invention, a touch-down bearing fixed to a shaft and having a touch-down clearance smaller than a bearing clearance is provided between the touch-down bearing and a guide roller. The internal clearance of the touch-down bearing may be negative (preload applied).

[0007]

Embodiments of the present invention will be described below.

As shown in FIG. 1, the air guide roller of this embodiment is fixed to a cylindrical guide roller 1, a shaft 2 inserted through an inner peripheral surface 1 a of the guide roller 1, and an outer peripheral surface of the shaft 2. The paired bearing sleeves 3 and the paired touchdown bearings 4 are main components.

At least an area 1a1 facing the bearing sleeve 3 and an area 1a2 facing the touchdown bearing 4 on the inner peripheral surface 1a of the guide roller 1 are finished smoothly. The region 1a2 is located at both ends of the guide roller 1,
Its inner diameter is larger than the inner diameter of the inner region 1a1. The outer peripheral surface 1b of the guide roller 1 is finished smoothly so that a tape, a film or the like can be guided. In addition, the touchdown bearing 4 is not limited to the both ends, but may be arranged on the inner side.

A series of air supply passages 2a are formed in the shaft 2.
An air supply hose 5 is connected to one end of the air supply passage 2a.

Each bearing sleeve 3 has a small radial bearing gap S between the inner peripheral surface 1a (region 1a1) of the guide roller 1 and
A bearing surface 3a opposed to the first bearing member 1 and a plurality of nozzles 3b opened in the bearing surface 3a are formed. Each nozzle 3b
Communicates with an air supply passage 2 a formed in the shaft 2.

As shown in FIG. 2 (part A in FIG. 1), the touch-down bearing 4 is fitted on the outer peripheral surface of the shaft 2.
The inner ring 4a positioned and fixed by the shoulder of the shaft 2 and the tightening nut 6 and the inner peripheral surface 1a of the guide roller 1 (region 1a)
Outer ring 4b opposed to 2) via touchdown gap S2
And a plurality of balls 4c interposed between the inner ring 4a and the outer ring 4b. Touchdown gap S2 dimension Cr
2 is set smaller than the dimension Cr1 of the radial bearing gap S1 by a predetermined amount (Cr2 <Cr1). Regarding the setting of the dimension Cr2 of the touch-down gap S2, when a touch-down bearing 4 having a negative bearing internal gap (preload application) is used, the run-out of the outer diameter surface of the outer ring 4b with respect to the shaft 2 is suppressed, and the guide roller 1 Inner surface 1a (region 1a)
Since the circumferential variation of the gap with 2) becomes small,
The dimension Cr2 can be set with high accuracy. Also, a step 1a between the end surface of the outer race 4b and the inner peripheral surface 1a of the guide roller 1
3 (a boundary between the region 1a1 and the region 1a2), an interval h is provided. The touch-down bearing is not limited to a deep groove ball bearing as shown in the figure, but may be another type of ball bearing such as an angular ball bearing. Further, the present invention is not limited to the ball bearing, and may be a roller bearing such as a cylindrical roller bearing and a tapered roller bearing. Furthermore, the bearing is not limited to a single-row bearing, and may be a double-row bearing. Further, the present invention is not limited to the rolling bearing, but may be a sliding bearing.

When compressed air is supplied from the air supply hose 5 shown in FIG. 1, the compressed air enters each nozzle 3b of the bearing sleeve 3 through the air supply passage 2a of the shaft 2, and from each nozzle 3b to the bearing gap S1. It is spouted toward. Then, due to the pressure distribution of the air film formed in the bearing gap S1, the guide roller 1 floats by the dimension Cr1 of the bearing gap S1, and is rotatably supported in a non-contact manner with respect to the bearing surface 3a.

On the other hand, if an excessive load exceeding the load capacity of the hydrostatic air bearing is applied during operation or the supply of compressed air is interrupted for some reason, the guide roller 1 is moved to the shaft 2 side. At this time, since the touch-down gap S2 is set smaller than the radial bearing gap S1 (Cr2 <Cr1), the touch-down bearing 4 (the outer diameter surface of the outer ring 4b) corresponds to the inner peripheral surface of the guide roller 1. 1a (area 1a2), and supports the load of the guide roller 1. Therefore, even if the above-mentioned disturbance factors occur during operation, the bearing surface 3a of the bearing sleeve 3 is always kept in a non-contact state with the inner peripheral surface 1a (region 1a1) of the guide roller 1, and therefore, both There is no seizure due to direct contact. Further, even when handling in a state in which compressed air is not supplied, such as during product transportation or assembly adjustment, the guide roller 1 is supported by the touch-down bearing 4 and is always kept in a non-contact state with the bearing surface 3a. Therefore, there is no need to securely fix the guide roller and the shaft with a fixing jig or the like as in the related art. Therefore, the handling of the product at the time of packing, transporting, opening the product, and adjusting the assembly is facilitated. Also, the components (shaft, bearing sleeve) of the hydrostatic air bearing are
The material cost and the processing cost can be reduced by using a material that is not restricted by the seizure resistance and gives priority to the workability and the dimensional accuracy when processing the nozzle and the bearing surface.

When the guide roller is supported in a non-contact manner not only in the radial direction but also in the thrust direction by a static pressure air bearing, for example, the interval h shown in FIG. 2 is smaller than the dimension of the thrust bearing gap of the thrust air bearing. By setting, direct contact between the thrust bearing surface and the guide roller can be prevented. That is, the present invention can be similarly applied to a touch-down structure of a thrust air bearing in addition to a touch-down structure of a radial air bearing, and in this case, the same effect as described above can be obtained.

[0016]

The present invention has the following effects.

(1) Since the bearing surface of the hydrostatic air bearing is always kept in a non-contact state with the guide roller, the problem of seizure due to direct contact between the two does not occur.

(2) Packing, transporting, unsealing work and assembling adjustment work of the product are facilitated.

(3) The constituent members of the hydrostatic air bearing are made of a material which is not restricted by seizure resistance and gives priority to workability and dimensional accuracy when machining nozzles and bearing surfaces. Cost and processing cost can be reduced.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view of a portion A in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Guide roller 1a Inner peripheral surface 2 Shaft 3a Bearing surface 4 Touchdown bearing S1 Bearing clearance S2 Touchdown clearance

Claims (2)

[Claims] 1. A guide shaft is inserted into an inner peripheral surface of a cylindrical guide roller, and compressed air is supplied to a bearing gap between the guide roller and a bearing surface provided on the shaft side, thereby forming the guide roller. An air guide roller rotatably and non-contactingly supported on a bearing surface, comprising: a touch-down bearing fixed to the shaft and having a touch-down gap smaller than the bearing gap between the guide roller and the air guide roller. Air guide roller with touchdown bearing. 2. The air guide roller with a touch-down bearing according to claim 1, wherein the internal clearance of the touch-down bearing is negative.