JP3932075B2 - Slide unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a slide unit having both functions of rotation with respect to a shaft and sliding in an axial direction.
[0002]
[Prior art]
For example, a spindle of a CMP (Chemical Mechanical Polishing) apparatus or the like requires a rotation function on one axis and a slide function in the axial direction. In order to satisfy such a rotation and slide function with one unit, conventionally, a large number of cages are held at regular intervals by a cage between a shaft and an outer cylinder arranged to surround the circumference. Stroke bearings with balls inserted (see, for example, JP-A-54-137542) and special-purpose units, helical grooves are formed on the outer peripheral surface of a shaft-shaped slider, and the slider is placed in a cylindrical case. The guide that engages with the helical groove is rotatably arranged on the inner surface of the case, and when the slider slides in the axial direction with respect to the case, the slider generates a rotational motion corresponding to the torsion angle of the helical groove. A helical guide device (see Japanese Patent Application Laid-Open No. 47-23972) is known.
[0003]
[Problems to be solved by the invention]
However, none of the conventional units described above is suitable for use in a spindle of a CMP apparatus or the like. In other words, the stroke bearing can perform rotation and slide in the axial direction independently, and can be used only for rotation, only for slide, or both at the same time. Since the ball is in contact with the cylindrical surface of the shaft and the inner cylindrical surface of the outer cylinder, the ball basically has almost point contact with each surface, and the surface pressure is inevitably high. Therefore, there is a drawback that the load capacity is insufficient.
[0004]
Further, the helical guide device proposed in Japanese Patent Application Laid-Open No. 47-23972 is one in which the slider slides in the axial direction and simultaneously rotates by an amount corresponding to the helical angle of the helical groove. However, it is not versatile and cannot be used for a spindle of a CMP apparatus.
[0005]
The present invention has been made in view of such circumstances, and has a function of rotating around an axis and sliding in the axial direction in one unit, and has a high load capacity, and is capable of rotating and sliding. The object is to provide a versatile slurry unit that can function independently of each other without interfering with each other.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, a slide unit of the present invention includes a cylindrical housing portion that is rotatably disposed around a shaft via a bearing, and a plurality of rollers that are in rolling contact with the outer peripheral surface of the housing portion. A cylindrical slider that is slidably disposed in the axial direction around the housing portion via the housing, and a guide slot that protrudes radially from the outer peripheral surface of the housing portion and extends in the axial direction formed in the slider It is characterized by having a rotation prevention member inserted in the inside (Claim 1).
[0007]
Here, in the present invention, each roller described above is constituted by a ball bearing, and the ball bearing is rotatably supported by a plurality of shafts mounted on the slider, and each shaft is supported with respect to the slider. As an eccentric shaft that is mounted so as to be adjustable in rotation, it is possible to adopt a configuration in which the clearance between the outer ring outer peripheral surface of each ball bearing and the outer peripheral surface of the housing portion can be adjusted by the rotation of each eccentric shaft. (Claim 2).
[0008]
In the present invention, the rotation preventing member that protrudes in the radial direction from the outer peripheral surface of the housing portion can be a rolling bearing that is in rolling contact with the inner surface of the guide hole.
[0009]
In the configuration of the invention according to claim 1, the housing portion is supported so as to be relatively rotatable with respect to the shaft by a normal bearing such as a radial ball bearing. Although the slider does not slide, a slider is provided outside the housing part so as to be slidable in the axial direction via a plurality of rollers, and the slider is prevented from rotating relative to the housing part by a rotation preventing member. By arranging in this manner, the slider can rotate relative to the shaft and can slide in the axial direction. In this configuration, the housing portion is supported on the shaft via a normal bearing, and the slider is supported on the housing portion via a plurality of rollers. Compared with the case where the outer cylinder is supported on the shaft via the ball, the load capacity is greatly improved.
[0010]
In addition, when a ball bearing is employed as a roller interposed between the housing portion and the slider, and each ball bearing is mounted on an eccentric shaft provided on the slider, the roller and its A high load capacity can be obtained without using special parts as the support mechanism, and at the same time, the clearance between the housing portion and each ball bearing can be easily adjusted, and high slide accuracy can be easily realized.
[0011]
Further, if the rotation preventing member protruding from the outer peripheral surface of the housing portion is a rolling bearing that is in rolling contact with the inner surface of the long guide hole of the slider, the sliding of the slider with respect to the housing portion is adopted. It is possible to reduce and equalize the dynamic resistance.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
1 is an external perspective view of an embodiment of the present invention, FIG. 2 is a longitudinal sectional view thereof, and FIG. 3 is an AA sectional view thereof.
[0013]
As shown in FIG. 2, the housing portion 1 has a cylindrical shape. Large diameter portions 1a and 1b are formed on the inner peripheral surfaces of both ends, and ball bearings are respectively formed on the large diameter portions 1a and 1b. 2 and 3 are fitted. As shown in FIGS. 1 and 3, the housing portion 1 is provided with female screws 1c at two locations facing the radial direction (only one location is shown in FIGS. 1 and 3). A bolt 5 into which a ball bearing 4 as a rotation preventing member of the moving part 6 described later is fitted is screwed, and the ball bearing 4 projects outward from the outer peripheral surface of the housing part 1 in the radial direction. In FIG. 2, reference numeral 1d denotes a collar that regulates the distance between the ball bearings 2 and 3 in the axial direction.
[0014]
A slider 6 having a substantially cylindrical shape as a whole is disposed outside the housing portion 1. For example, about 20 through windows 6a are formed in the slider 6, and miniature or small-diameter ball bearings 7 are supported in the through windows 6a. The outer ring of each ball bearing 7 protrudes from the through window 6 a to the inner peripheral surface side of the slider 6 and is in rolling contact with the outer peripheral surface of the housing portion 1. Further, as shown in FIG. 1, the slider 6 is formed with guide long holes 6c corresponding to the respective ball bearings 4 as rotation preventing members protruding outward from the outer peripheral surface of the housing portion 1 described above. The ball bearings 4 are fitted into the guide long holes 6 c so that the outer peripheral surface of the outer ring is in rolling contact with either one of the inner surfaces on both sides of the guide long hole 6. Accordingly, the slider 6 is prevented from rotating relative to the housing portion 1 due to the presence of the ball bearings 4, and can slide in the axial direction via the ball bearings 7.
[0015]
Each ball bearing 7 for sliding disposed in each through window 6 a of the slider 6 has a clearance adjusting function with respect to the outer peripheral surface of the housing portion 1. That is, as shown in FIG. 3, each through window 6 a is formed with a hole 6 b that is orthogonal to each through window 6 a and extends between both side surfaces, and an eccentric shaft 8 is formed in each hole 6 b. Are inserted at both ends. The eccentric shaft 8 has a small-diameter distal end portion 8a and a large-diameter base end portion 8b, which are respectively inserted into the holes 6b on both side surfaces of the through window 6a with the same axial center. These are composed of an eccentric portion 8c whose axis is shifted by a predetermined dimension, and the ball bearing 7 is fitted into the eccentric portion 8c. The end surface of the base end portion 8b of the eccentric shaft 8 faces the outside through a counterbore-shaped cutout portion 6d formed on the outer peripheral surface of the slider 6 so as to correspond to each through hole 6a. A hexagonal hole 8d is formed on the end surface of the portion 8b. Further, the distal end portion 8 a and the proximal end portion 8 b of the eccentric shaft 8 can be tightened by a set bolt 9 screwed from the outer periphery of the slider 6. The eccentric amount of the eccentric portion 8c is slightly smaller than ½ of the dimensional difference between the small-diameter distal end portion 8a and the large-diameter base end portion 8b, whereby the eccentric shaft 8 enters the hole 6b from the notched portion 6d. Can be inserted.
[0016]
With the above configuration, when the eccentric shaft 8 is rotated with the set bolt 9 loosened, the ball bearing 7 advances and retreats with respect to the outer peripheral surface of the housing portion 1 in the through window 6a, and the clearance between the two is adjusted. can do. By setting the clearance between each ball bearing 7 and the outer peripheral surface of the housing portion 1 to a uniform appropriate amount and tightening each set bolt 9, the slider 6 and the housing portion 1 are relatively moved with high accuracy. Can be slid.
[0017]
As shown in FIG. 2, the slide unit of the above embodiment has the inner ring inner peripheral surfaces of the two ball bearings 2, 3 arranged at both ends of the housing portion 1 as the outer peripheral surface of the shaft S passing through them. Used in a fixed state. In this use state, the housing part 1 can rotate relative to the shaft S via the bearings 2 and 3, the slider 6 cannot rotate relative to the housing part 1 as described above, and the shaft Since the slider 6 can be slid in the direction, the slider 6 can rotate relative to the axis S and can slide in the axial direction, and both functions of rotation and sliding can be satisfied by one unit.
[0018]
In addition, since the rotation operation of the housing part 1 with respect to the axis S and the sliding operation of the slider 6 with respect to the housing part 1 do not interfere with each other independently, only rotation, only slide, and rotation and sliding simultaneously Any of these operating states can be adopted. In addition, the housing portion 1 is supported by the two ball bearings 2 and 3 with respect to the shaft S, and the slider 6 is supported by the housing portion 1 through a plurality of ball bearings 7. The load capacity with respect to is large and can be sufficiently used for the spindle portion of the CMP apparatus. Furthermore, the sliding stroke of the slider 6 with respect to the housing portion 1 can be arbitrarily set according to the length of the guide long hole 6c.
[0019]
Here, in the above embodiment, the shaft S is used as a fixed shaft, the housing portion 1 is rotatably supported around the shaft S, and the slider 6 is rotated and slidable. A method of using a slider 6 that is rotatably supported and a slider 6 that does not rotate around the rotating shaft S is slidably arranged, and the slider 6 is fixed and the shaft S can be rotated relative to the slider 6. Of the usage methods for slidably arranging the supported housing portion 1, any method can be employed.
[0020]
In the above embodiment, an example in which a plurality of ball bearings 7 are interposed between the housing portion 1 and the slider 6 has been described. However, instead of this ball bearing, the ball bearing 7 is rotatably supported by the slider 6. A roller may be interposed.
[0021]
In addition, when the sliding resistance of the slider 6 with respect to the housing portion 1 does not cause a problem, a simple protrusion may be provided as a rotation preventing member instead of the ball bearing 4.
[0022]
【The invention's effect】
As described above, according to the present invention, a plurality of rollers that are in rolling contact with the outer peripheral surface of the housing portion are provided around the cylindrical housing portion that is rotatably disposed around the shaft via a bearing. In addition, a cylindrical slider that is slidable in the axial direction is provided, and the slider is provided with a long guide hole into which the rotation prevention member protruding from the outer peripheral surface of the housing portion is provided. Are relatively rotatable and slidable in the axial direction, so that one unit can have a rotation function and a slide function independent of each other. Moreover, since the slider is supported on the housing part via a plurality of rollers, and the housing part is supported on the shaft via a bearing, a point contact ball is interposed like a conventional stroke bearing. As compared with the above, the load capacity can be greatly improved.
[0023]
In addition, by adopting a structure in which the roller interposed between the housing part and the slider is a ball bearing and each ball bearing is mounted on the slider via an eccentric shaft, the clearance between the ball bearing and the housing part is easy. A unit having a highly accurate slide function can be obtained without using special parts and with a simple configuration.
[0024]
Furthermore, if a structure using a rolling bearing that is in rolling contact with the inner surface of a long hole provided in the slider is employed as a rotation prevention member for the slider housing, the sliding resistance against the slider housing is reduced based on an inexpensive structure. Reduction and equalization can be achieved.
[Brief description of the drawings]
FIG. 1 is an external perspective view of an embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of an embodiment of the present invention.
3 is a cross-sectional view taken along the line AA in FIG.
[Explanation of symbols]
1 Housing parts 2, 3 Ball bearings (for rotation)
4 Ball bearing (rotation prevention member)
6 Slider 6a Through window 6b Hole 6c Long slot for guide 7 Ball bearing (for slide)
8 Eccentric shaft

Claims (3)

A cylindrical housing portion that is rotatably disposed around a shaft via a bearing, and a plurality of rollers that are in rolling contact with the outer peripheral surface of the housing portion, and are slidable in the axial direction around the housing portion. A slide unit comprising: an arranged cylindrical slider; and a rotation prevention member that protrudes in a radial direction from the outer peripheral surface of the housing portion and is inserted into an elongated guide hole formed in the slider in the axial direction. Each roller is a ball bearing and is rotatably supported by a plurality of shafts mounted on the slider, and each shaft is an eccentric shaft mounted so as to be rotatable and adjustable with respect to the slider. 2. The slide unit according to claim 1, wherein a clearance between an outer ring outer peripheral surface of each ball bearing and an outer peripheral surface of the housing portion can be adjusted by rotation of each eccentric shaft. The slide unit according to claim 1 or 2, wherein the rotation preventing member is a rolling bearing that is in rolling contact with the inner surface of the guide hole.

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