1. Field of the Invention
The present invention relates to a testing device for conducting various tests of a thin-walled large bearing used in, for example, a CT scanner device which is a medical examination device.
2. Description of Related Art
A CT scanner device (for example,
Generally, the bearing for supporting the rotating mount of the CT scanner device is required to have the following performances.
(1) Silence. This prevents an organ from being contracted due to patient's tension, and gives a sense of ease to the patient, to keep the organ acting normally.
(2) Low vibration. The lower the vibration is, the higher the quality of a captured image is.
(3) High speed. Shortening a time needed for imaging reduces the X-ray exposed dose.
In order to assure the above performances of the bearing for supporting the rotating mount, it is necessary to conduct a performance evaluation test before the bearing is incorporated into the CT scanner device. An example of such testing devices is disclosed in Patent Document 2. This testing device holds the bearing such that the bearing can be tilted at any angle, by a bearing holding mechanism, and allows an inner ring of the held bearing to be rotated at any rotation speed, thus enabling a performance evaluation test of the bearing under various conditions.
[Patent Document 2] JP Laid-open Patent Publication No. 2005-315681
Patent Document 2 describes that, since the baring can be tilted at any angle, the testing device is capable to make “the attachment orientation of the bearing be the same as that of, for example, a rolling bearing used for supporting a CT scanner gantry head”. However, the specification of Patent Document 2 does not disclose that the bearing can be held horizontally. In addition, since the testing device is such a type that the bearing is fixed by being fitted into a depressed portion of a housing, the bearing can be fixed to the housing even when the bearing is in a vertical orientation. Thus, it is considered that, in this testing device, the bearing is attached to the bearing holding mechanism in a state in which the bearing is set in a vertical orientation or in a tilted orientation. Since the bearing used in the CT scanner device is large and heavy, it is not easy to attach the bearing to the bearing holding mechanism while a person supports the bearing in an appropriate orientation. In addition, when the bearing is in a vertical orientation or in a tilted orientation, a gap between the bearing holding mechanism and the bearing becomes uneven in the circumferential direction due to the influence of the weight of the bearing, and therefore it is difficult to attach the bearing at the center of the bearing holding mechanism.
An object of the present invention is to provide a testing device for a thin-walled large bearing, that allows the thin-walled large bearing as a test target to be easily and accurately installed and allows a performance evaluation test to be conducted with the installed thin-walled large bearing tilted in any orientation.
A testing device for a thin-walled large bearing of the present invention includes: a face board configured to allow the thin-walled large bearing as a test target to be installed thereon; a face board support mechanism configured to support the face board such that the face board can be tilted around a tilting central shaft set to be horizontal, the tilting central shaft coinciding with or being parallel with a diameter line of the bearing installed on the face board; an angle change drive device configured to change a tilt angle of the face board; and a bearing rotation motor installed on the face board and configured to rotate an inner ring of the bearing. The face board support mechanism and the angle change drive device are capable of changing an orientation of the face board in a range from a horizontal orientation through a vertical orientation to a tilted orientation. The face board is provided with a bearing installation mechanism configured to install the bearing such that the bearing is placed on the face board and an outer ring of the bearing is fixed. The “thin-walled large bearing” as the test target in the present invention refers to a bearing in which a difference between an inner diameter and an outer diameter thereof with respect to the inner diameter is smaller than that of a general bearing, and the inner diameter is great, for example, a bearing in which a value of (outer diameter−inner diameter)/(inner diameter) is 0.3 or smaller and the inner diameter is 600 mm or greater.
According to the above configuration, the face board is set in the horizontal orientation by the face board support mechanism and the angle change drive device, and the bearing is installed by the bearing installation mechanism in a state in which the bearing is placed on the face board set in the horizontal orientation. Since the face board is horizontal, it is only necessary to lower the bearing set in the horizontal orientation from above onto the face board in installation of the bearing, and it is not necessary to support the bearing in a proper orientation by a person. Therefore, even if the bearing is the thin-walled large bearing, the bearing can be easily installed on the face board. In addition, when the bearing is placed on the face board set in the horizontal orientation, the weight of the bearing is uniformly applied to the face board. Therefore, position adjustment of the bearing along a bearing placement surface of the face board can be easily performed, and the bearing can be accurately installed at the center of the face board. Further, since the installation is performed in a state in which the bearing is placed on the face board, application to bearings having various outer diameters is easy, unlike a method in which a bearing is fitted into a face board.
After the bearing is installed on the face board, the face board is set in the vertical orientation or the tilted orientation, and the inner ring of the bearing installed on the face board is rotated by the bearing rotation motor, whereby a performance evaluation test of the bearing is conducted. Since the angle of the face board can be changed to any tilt angle or a predetermined tilt angle, the performance evaluation test of the bearing can be conducted in a state close to a usage state.
In the present invention, the bearing installation mechanism may include: a ring-shaped general-purpose frame which is detachably provided on the face board and is capable of selectively and concentrically fixing each of bearings having plural types of outer diameters; and a frame fixing module configured to fix the general-purpose frame to the face board. In this case, application to plural types of bearings having different outer diameters is enabled with a single bearing installation mechanism. In addition, the bearing can be fixed to the general-purpose frame at a place separated from the testing device, and the general-purpose frame to which the bearing is fixed can be fixed to the face board. Even if the type of the outer diameter of the bearing fixed to the general-purpose frame differs, operation for fixing the general-purpose frame to the face board is the same, and therefore work for installing the bearing on the face board is simplified.
The frame fixing module may include: a bolt insertion hole formed in the general-purpose frame or the face board; and a fixation bolt to be inserted into the bolt insertion hole so as to form an adjustment gap therebetween, to fix the general-purpose frame to the face board. A positioning mechanism may be provided which is configured to cause a center of the general-purpose frame to coincide with a center of the face board before fastening by the fixation bolt is performed. The positioning mechanism may be composed of: eccentric contact members rotatably provided at an eccentric position around a central axis perpendicular to the face board, to contact with respective plural positions of an outer circumferential surface of the general-purpose frame; and a rotation preventing module configured to switch the eccentric contact member between a rotation prevented state and a rotation allowed state.
In this case, the general-purpose frame is fixed to the face board through the following procedure. First, the general-purpose frame to which the bearing as the test target is fixed is placed roughly at a target installation position on the face board. At this stage, the general-purpose frame has not been fixed to the face board yet, and the general-purpose frame can be moved within a range of the adjustment gap between the bolt insertion hole and the fixation bolt. In this state, the center of the general-purpose frame is caused to coincide with the center of the face board by the positioning mechanism. Then, the fixation bolt is fastened to fix the general-purpose frame to the face board. The positioning mechanism is composed of plural sets of the eccentric contact member and the rotation preventing module, and is configured to cause the eccentric contact members to contact with the respective plural positions of an outer circumferential surface of the general-purpose frame, thereby positioning the general-purpose frame. Therefore, the mechanism is simple, and the positioning operation is easy.
In the present invention, a weight may be provided which is detachably attached to the inner ring of the bearing, to generate a moment load to the bearing. By providing the weight, the same moment load as that would be applied to the bearing in a usage state can be applied to the bearing.
In the present invention, a face board fixing mechanism configured to fix the face board to the face board support mechanism at any tilt angle or a predetermined tilt angle may be provided separately from the angle change drive device. By providing the face board fixing mechanism, the tilt angle of the face board can be prevented with high accuracy from being unintentionally changed during a test or the like.
Thus, the testing device for the thin-walled large bearing of the present invention is suitable for conducting a performance evaluation test of a bearing for supporting a rotating mount of a CT scanner device.
Any combination of at least two constructions, disclosed in the appended claims and/or the specification and/or the accompanying drawings should be construed as included within the scope of the present invention. In particular, any combination of two or more of the appended claims should be equally construed as included within the scope of the present invention.
In any event, the present invention will become more clearly understood from the following description of preferred embodiments thereof, when taken in conjunction with the accompanying drawings. However, the embodiments and the drawings are given only for the purpose of illustration and explanation, and are not to be taken as limiting the scope of the present invention in any way whatsoever, which scope is to be determined by the appended claims. In the accompanying drawings, like reference numerals are used to denote like parts throughout the several views, and:
An embodiment of a testing device for a thin-walled large bearing according to the present invention will be described with reference to
In
The angle change drive device 4 is a device for changing a tilt angle of the face board 2 around the central axis C1 of the tilting central shaft 12. The angle change drive device 4 includes a rotation transmission mechanism 16 composed of: a rotated element 14 fixed on one (in the example shown in the drawings, right one) of the right and left side surfaces of the face board 2; and a rotating element 15 provided on the frame 10. The angle change drive device 4 tilts the face board 2 together with the rotated element 14 by rotating the rotating element 15 by a rotational drive source 17 such as a motor provided on the frame 10. The rotation of the rotational drive source 17 is transmitted to the rotating element 15 via a reduction gear (not shown) such as a worm reduction gear so that the speed of the rotation is reduced. For example, the rotated element 14 is formed by attaching a chain 14a in a fixed manner to the outer circumference of a fan-shaped plate material centered on the central axis C1 of the tilting central shaft 12. The rotating element 15 is a sprocket having a claw 15a formed on the outer circumference thereof and to be engaged with the chain 14a. The rotated element 14 and the rotating element 15 may be gears having teeth engaged with each other.
As shown in
The face board fixing mechanism 5 is a mechanism for fixing the face board 2 to the face board support mechanism 3, at any tilt angle or a predetermined tilt angle.
Instead of the above configuration, the screw shafts 21A, 21B, and 21C may be provided in a fixed state to the face board 2, and a nut (not shown) screwed to each screw shaft 21A, 21B, 21C may be fastened to fix the face board 2 to the fixation plate 20 by means of a friction force between the nut and the fixation plate 20. In the example in
The bearing installation mechanism 6 is a mechanism for installing the bearing 60 as the test target in a state in which the bearing 60 is placed on the face board 2, and includes: a general-purpose frame 30 to which an outer ring 60a (
As shown in
The frame fixing module 31 is composed of: a bolt insertion hole 36 formed along the axial direction in the general-purpose frame 30; a screw hole 37 formed in the face board 2 so as to correspond to the bolt insertion hole 36; and a fixation bolt 38 to be inserted through the bolt insertion hole 36 and screwed into the screw hole 37. When the fixation bolt 38 is inserted into the bolt insertion hole 36, an adjustment gap 39 is formed therebetween at least in the radial direction. In order to form the adjustment gap 39, the bolt insertion hole 36 is formed to be a circular hole having a greater hole diameter than the diameter of the fixation bolt 38, or a long hole elongated in the radial direction.
The fixation bolt 38 inserted through the bolt insertion hole 36 is screwed into the screw hole 37 to fix the general-purpose frame 30 to the face board 2, and here, a positioning mechanism 41 (
As shown in
As shown in
In
As shown in
A usage method of the testing device 1 will be described. By the face board support mechanism 3 and the angle change drive device 4, the face board 2 is set in the horizontal orientation as shown in
In detail, the installation of the general-purpose frame 30 on the face board 2 is performed through the following procedure. First, the general-purpose frame 30 to which the bearing 60 as the test target has been fixed is placed roughly at a target installation position on the face board 2, using a crane or the like. Then, the fixation bolt 38 is inserted into the bolt insertion hole 36 of the general-purpose frame 30, and the fixation bolt 38 is screwed into the screw hole 37 of the face board 2. At this stage, the fixation bolt 38 is not completely screwed into the screw hole 37. Therefore, the general-purpose frame 30 has not been fixed to the face board 2 yet, and the general-purpose frame 30 can be moved within a range of the adjustment gap 39 between the bolt insertion hole 36 and the fixation bolt 38.
In this state, by the positioning mechanism 41, the general-purpose frame 30 is positioned such that the center of the general-purpose frame 30 coincides with the center O of the face board 2. The positioning method is as follows: the eccentric contact member 42 of each of the positioning mechanism portions 41A and 41B is set in a rotation allowed state, and is rotated so that the largest radius portion of the eccentric contact member 42 is directed toward the center O of the face board 2 as shown by a solid line in
After the general-purpose frame 30 is fixed to the face board 2, the rotation prevented state of the eccentric contact member 42 is cancelled, and the eccentric contact member 42 is rotated to direct the smallest radius portion thereof toward the center O of the face board 2, so that the eccentric contact member 42 does not contact with the general-purpose frame 30. Thus, during a test, wearing of the bearing 60 as the test target due to fretting of the eccentric contact member 42 can be prevented.
Thus, in the case where the general-purpose frame 30 is installed on the face board 2 set in the horizontal orientation, it is only necessary to lower the general-purpose frame 30 from above onto the face board 2 in installation of the bearing, and it is not necessary to support the general-purpose frame 30 in a proper orientation by a person. Therefore, even if the bearing 60 as the test target is the thin-walled large bearing with a great weight, the general-purpose frame 30 can be easily installed on the face board 2. When the general-purpose frame 30 is placed on the face board 2 set in the horizontal orientation, a load from the bearing 60 as the test target and the general-purpose frame 30 is uniformly applied to the face board 2. Therefore, position adjustment of the general-purpose frame 30 along a bearing installation surface 2b of the face board 2 can be easily performed, and the bearing 60 as the test target can be accurately installed at the center of the face board 2.
After the general-purpose frame 30 is installed on the face board 2, the driven pulley 55 and the weights 58A, 58B, and 58C are attached to the inner ring 60b of the bearing 60 as the test target. The driven pulley 55 and the weights 58A, 58B, and 58C may be attached to the inner ring 60b of the bearing 60 as the test target before the general-purpose frame 30 is installed on the face board 2. Finally, the belt 56 is wound around the driving pulley 54 and the driven pulley 55, whereby test preparation is completed.
After the test preparation is completed, the face board 2 is set in the vertical orientation or the tilted orientation, to conduct a performance evaluation test of the bearing 60 as the test target. At this time, the face board 2 is fixed at a determined tilt angle by the face board fixing mechanism 5. Thereby, the tilt angle of the face board 2 can be reliably prevented from being unintentionally changed during a test or the like, thus ensuring security. The performance evaluation test is conducted by rotating the inner ring 60b of the bearing 60 as the test target by the bearing rotation motor 52 and then reading a value detected by each of the above sensors. Since the face board 2 can be changed at any tilt angle or a predetermined tile angle, the performance evaluation test of the bearing 60 as the test target can be conducted in a state close to the usage state.
The CT scanner device 70 shown in
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings which are used only for the purpose of illustration, those skilled in the art will readily conceive numerous changes and modifications within the framework of obviousness upon the reading of the specification herein presented of the present invention. Accordingly, such changes and modifications are, unless they depart from the scope of the present invention as delivered from the claims annexed hereto, to be construed as included therein.
Number | Date | Country | Kind |
---|---|---|---|
2013-152397 | Jul 2013 | JP | national |
This application is a continuation application, under 35 U.S.C. §111(a), of international application No. PCT/JP2014/068673, filed Jul. 14, 2014, which claims priority to Japanese patent application No. 2013-152397, filed Jul. 23, 2013, the entire disclosure of which is herein incorporated by reference as a part of this application.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/JP2014/068673 | Jul 2014 | US |
Child | 15001870 | US |