JP2017029648A - Rolling bearing unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing unit which does not cause support deviation of a rail such as a C-arm of X-ray equipment due to a support roller.SOLUTION: A rolling bearing unit B supports a C-arm 4 movably, and supports the aluminum C-arm 4 by plural pulley built-in tensioners 10. These tensioners are formed of a roller follower and an auto tensioner (torsion spring and the like), the roller follower can always support and move the C-arm 4 at proper contact pressure by the auto tensioner. Therefore, a correct X-ray imaged image can be acquired, and it is possible to easily cope with improvement of resolution of the X-ray equipment in recent years. Since a resin coating is employed on an outer ring exterior cladding of the roller follower, so that, rolling contact between the aluminum and the resin is achieved, so that injection of a lubricant such as a grease required in rolling contact between irons, is not required, in which smooth movement of the C-arm 4 can be secured over a long term, and there is no probability of contamination in a surrounding environment, due to scattering of the lubricant.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rolling bearing unit that supports a rail having a rolling groove such as a C arm of an X-ray apparatus as a medical device so as to be movable in its length direction.

For example, an X-ray apparatus will be described with reference to FIG. 1 showing an embodiment of the present invention. An X-ray source (X-ray tube) 5 which is a heavy object and an image receiver at both ends of the C-arm 4. An (X-ray detector) 6 is attached, and the C arm 4 operates around the human body while supporting the X-ray tube 5 and the image receiver 6 and takes an X-ray photograph.
The C-arm 4 in this X-ray apparatus normally constitutes a supporting rolling member by arranging a plurality of roller followers, and these support the C-arm 4 by rolling in a rail groove (rolling groove). (See Patent Document 1 FIGS. 1 and 5).

The rolling member of the C-arm 4 of the conventional X-ray apparatus has a structure in which a radial follower roller follower and an axial receive roller follower are combined. In this structure, the rail on which the roller on the outer diameter of the roller follower rolls has a curvature, there is a machining error in the machining curved surface, and there is a machining error in the support hole of the eccentric shaft of the roller follower. It is necessary to adjust the contact between the roller follower (the roller) and the rail by an eccentric shaft or shim.
In addition, this C-arm rolling member is attached to one X-ray apparatus and is composed of several roller followers. The roller follower is eccentrically supported so as to be swingable, and the swing angle is adjusted. It also adjusts the contact with the rail.

JP 09-238931 A No. 07-49106 JP 2011-106483 A

The adjustment of the contact between the roller follower and the rail is a complicated operation, which causes a decrease in work efficiency and requires skill.
If the adjustment work is not performed well and the contact state between the roller follower and the rail is not appropriate, a backlash occurs each time the roller rolls in the support portion of the C arm by the rolling member, and the moving body (X-ray tube and image) The center of gravity of the receiver will shift.

In addition, since this X-ray apparatus is diagnosed with the patient located in the C arm, the radius of curvature of the rail (C arm) is approximately 1 to 2 m, and the rail cross section is also 200 mm × 200 mm. In addition to its high rigidity, the moving body (X-ray tube etc.) is also a heavy object of about 5 to 10 kg. Therefore, at the initial stage of assembly, the outer ring outer diameter surface of the roller follower and the rail can be adjusted by adjusting shims. Even if the contact is adjusted, it is difficult to always maintain the optimum contact state between the roller follower and the rail. If the contact state is not appropriate, the roller will be rattled each time the roller rolls. The center of gravity of the body will shift.
Further, the roller follower itself usually has a radial gap of 10 to several tens of μm, and when the roller follower moves from the load area to the anti-load area, the gap of the moving body is increased by the gap. The displacement of the center of gravity.

When these center-of-gravity shift | offset | difference arises, a shift | offset | difference will arise in a X-ray picked-up image, and a picked-up image will become unclear. When this center-of-gravity shift occurs, the contact adjustment between the roller follower and the rail is adjusted each time to correct the shift. In the meantime, the X-ray imaging examination will be stopped and the patient will wait.
It is necessary to improve the environment in which such a shift occurs, and since the resolution of the X-ray apparatus has been improved in recent years, there is a high demand for eliminating the play due to the shift.

  This invention makes it a subject to eliminate the backlash adjustment by the said shift | offset | difference under the above actual condition.

In order to achieve the above object, according to the present invention, the roller follower is always pressed against the rolling surface of the rail rolling groove such as the C arm by pressing means such as a spring.
As described above, if the roller follower is constantly pressed against the rolling surface, no deviation occurs, and stable rail movement can be ensured.

According to the present invention, there is provided a rolling bearing unit that supports a rail having a rolling groove so as to be movable in its length direction, a plurality of roller followers that are movably fitted in the rolling groove, and the roller follower. It is possible to adopt a configuration having pressing means for bringing the roller into contact with the rolling surface of the rolling groove.
In this configuration, if the outer surface of the roller follower is coated with a resin, the rolling noise can be reduced, the frequency of injection of the lubricant can be reduced, or the injection can be eliminated. Further, it is more durable than the resin roller itself.
There are various modes for the configuration of the rail, for example, as an arc shape, both side surfaces of the rolling groove are rolling surfaces, and the roller follower rolls on both rolling surfaces. It can be. In the case of this arc, it can be the C arm of the X-ray device.
The pressing means may have various modes. For example, the pressing means may have an auto tensioner in which the roller follower is swingable and a spring that is pressed against the rolling surface of the rolling groove is attached. .

  In the present invention, as described above, since the roller follower is constantly pressed against the rolling surface of the rolling groove by pressing means such as a spring, the rail can be moved stably without play. In particular, when the rail is a C-arm of an X-ray apparatus, the frequency of adjustment due to the play is extremely low, and X-ray imaging without the adjustment becomes possible, leading to a reduction in patient examination time and more precise examination. Is possible.

Schematic diagram of one embodiment of an X-ray apparatus employing a rolling bearing unit according to the present invention Main part enlarged schematic view of the same embodiment 2 is a cross-sectional view of FIG. 2, (a) is II line, (b) is II-II line.

1 to 3 show an embodiment of an X-ray apparatus employing a rolling bearing unit according to the present invention. The X-ray apparatus A of this embodiment can be rotated on a fixed support (arm, leg, etc.) 1. A support arm 2 is attached to be rotatable about a horizontal axis, and a support member 3 having a rolling bearing unit B according to the present invention is attached to the support arm 2. An aluminum C-arm 4 is supported on the support member 3 so as to be movable in the length direction, and an X-ray tube 5 and an image receiver 6 are attached to both ends of the C-arm 4.
In the X-ray apparatus A, the C arm 4 is rotated (in the direction of the arrow of the support arm 2) or moved in the length direction (in the direction of the arrow) in the same manner as in the past. X-ray imaging. Its movement is computer controlled.

As shown in FIGS. 2 and 3, the C arm 4 has a U-shaped cross section (grooved steel / channel shape), and the flange inner surfaces on both sides thereof are rolling surfaces 4a and 4b.
The supporting member 3 that supports the C-arm 4 so as to be movable in the length direction has two sets of rolling bearing units B according to the present invention. Three or more pairs can be used.
Each rolling bearing unit B has three pulley built-in tensioners 10 along the length direction of the C arm 4 in a boulder 7 constituting a part of the casing of the support member 3. There may be a plurality of tensioners 10 with a built-in pulley, and two, three, four or more, etc. are optional.

As shown in FIG. 3, the pulley built-in type tensioner 10 includes a roller follower 11 and an auto tensioner.
The roller follower 11 includes an inner ring 11a, an outer ring 11b, and a ball 11c therebetween. The outer ring 11b is rotatable with respect to the inner ring 11a via the ball 11c. The eccentric shaft 11d of the inner ring 11a is fixed to the boulder 7 with its screw portion 14, and the roller follower 11 swings (rotates) around the eccentric shaft 11d by fixing the eccentric shaft 11d to the boulder 7. Move).
A resin coating 13 is applied to the outer peripheral surface of the outer ring 11a.

  The auto tensioner includes, for example, a torsion spring 12 (see Patent Document 2, FIG. 2 and the like). One end of the spring 12 is fixed to the eccentric shaft 11d and the other end is fixed to the inner ring 11a. Is always biased in one direction of rotation. The urging force is set such that the roller follower 11 (outer ring 11b, resin coating 13) is pressed against the rolling surfaces 4a and 4b and the resin coating 13 is not deformed, for example, about 100 kgf.

As shown in FIGS. 2 and 3A, one of the boulders 7 and 7 having the pulley built-in type tensioner 10 of this configuration is such that the outer ring 11b (resin coating 13) of each roller follower 11 is located inside the C arm 4. 2 and 3B, the outer ring 11b of each roller follower 11 is in contact with the outer rolling surface 4b of the C arm 4, as shown in FIGS. Is attached.
In this mounted state, the support surface formed by each roller follower 11 of each boulder 7 is circular and has the same curvature as the rolling surface 4 a or 4 b of the C arm 4. Therefore, the support member 3 having both the boulders 7 and 7 supports the C arm 4 so as to be movable on the same arc in the length direction.

  The X-ray apparatus A of this embodiment has the above-described configuration. Now, with the patient positioned at the center of rotation of the C-arm 4, the C-arm 4 is rotated or moved in the length direction as in the prior art. X-ray imaging at a required position.

  At this time, if the C arm 4 is displaced due to the bending of the C arm 4 or the like, each pulley built-in type tensioner 10 causes the roller follower 11 to be optimal for the rolling surfaces 4a and 4b by the auto tensioner (spring 12). Contact is made by pressing force (arrow in FIG. 2). By this action, the optimum contact state between the roller follower 11 and the rail (the rolling surfaces 4a and 4b of the C arm 4) is maintained, and stable movement of the C arm 4 is ensured. For this reason, the center-of-gravity shift of the moving body due to the movement of the C arm 4 is eliminated, and the captured image is not blurred.

  Further, since the resin coating 13 is employed for the outer ring 11b of the roller follower 11, the outer ring 11b and the rolling surfaces 4a, 4b are rolling contact rolling between the resin and aluminum, and iron and iron In addition, it is not necessary to inject lubricating oil such as grease as in the case of rolling between the two, ensuring smooth movement of the C-arm 4 over a long period of time, and there is no possibility of contaminating the surrounding environment due to scattering of the lubricating oil.

  As described above, since the C-arm 4 moves stably, an accurate X-ray image can be obtained, and it is possible to easily cope with the recent improvement in resolution of the X-ray apparatus.

In the above embodiment, the urging mechanism (auto tension) of the roller follower 11 by the auto tensioner has various conventional configurations, for example, a free arm integrated type described in Patent Document 3 and a pulley built-in type by an elastic body other than a torsion spring. Etc. can be adopted as appropriate. Further, the roller follower 11 is not limited to the illustrated configuration, and other configurations such as a configuration using needle rollers instead of the balls 11c may be employed.
Although the X-ray apparatus A is a ceiling suspension type, the present invention can be applied to various types of X-ray apparatuses such as a ceiling traveling type, an installation type, and an installation movement type.
Of course, the present invention is not limited to the X-ray apparatus, and can be applied to a rolling bearing unit that supports a rail having a rolling groove so as to be movable in its length direction.
Thus, it should be thought that embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

A X-ray device B Rolling bearing unit 1 Support body 2 Support arm 3 Support member 4 C arm 4a, 4b Rolling surface 5 of C arm X-ray tube 6 Image receiver (X-ray detector)
7 Bolder 10 Pulley built-in tensioner 11 Roller follower 11a Roller follower inner ring 11b Same outer ring 11c Same ball 11d Eccentric shaft 12 Torsion spring 13 of auto tensioner Resin coating 14 of outer ring of roller follower 14 Eccentric shaft mounting thread of roller follower

Claims (5)

  A rolling bearing unit (B) that supports a rail (4) having a rolling groove movably in its length direction, and a plurality of roller followers (11) that are movably fitted in the rolling groove, A rolling bearing unit having pressing means for bringing the outer ring (11b) of the roller follower (11) into contact with the rolling surfaces (4a, 4b) of the rolling groove.   The rolling bearing unit according to claim 1, wherein an outer peripheral surface of the outer ring (11 b) of the roller follower (11) is resin-coated (13).   The rail (4) is arc-shaped, and both side surfaces of the rolling groove are rolling surfaces (4a, 4b), and the outer ring of the roller follower (11) is formed on both rolling surfaces (4a, 4b). The rolling bearing unit according to claim 1 or 2, characterized in that (11b) rolls.   4. The roller follower (11) according to any one of claims 1 to 3, wherein the roller follower (11) has a spring (12) which can swing and presses against a rolling surface (4a, 4b) of the rolling groove. The rolling bearing unit according to claim 1.   5. A rolling bearing unit according to claim 1, wherein the rail is a C arm (4) of an X-ray apparatus (A).

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