JP2614430B2 - Spherical bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spherical bearing applicable to precision measuring instruments, precision processing machines, precision positioning mechanisms and the like.

[0002]

2. Description of the Related Art As shown in FIGS. 6 and 7, a conventional spherical bearing 1 is a so-called sliding bearing. Alternatively, a pair of outer peripheral members 3a, 3
b, and fixed with the fastening screw 4, and the rod 2
Is configured to be rotatable.

[0003]

However, in such a spherical bearing 1, since a gap is required between the distal end portion 2a of the rod 2 and the outer peripheral member 3, play is produced, and the accuracy is accordingly reduced. descend. Also, if you reduce this gap,
There is a disadvantage that the contact resistance between the distal end portion 2a of the rod 2 and the outer peripheral member 3 becomes large, and the movement becomes slow. Further, since the gap may cause the distal end portion 2a of the rod 2 to come off from the outer peripheral member 3, the allowable inclination angle cannot be set large. The present invention has been proposed in view of the above background, and an object of the present invention is to provide a spherical bearing having a rolling bearing structure, which has no backlash, a small friction coefficient, and a relatively large allowable inclination angle. I do.

[0004]

In order to solve the above-mentioned problems, the present invention relates to a spherical bearing for holding a rod so as to be pivotable within a predetermined angle range. Part, and this tip part is
It is configured to surround and support through a number of rolling elements, and to support the retainer on an outer peripheral member attachable to the apparatus main body. The retainer is provided with a through hole for rotatably holding a number of rolling elements. The through hole for holding the rolling element is slightly larger than the outer diameter of the rolling element on the inner peripheral surface side of the retainer, while the outer diameter of the rolling element is When the rolling element is disposed in the through hole, the rolling element protrudes to both the inner peripheral surface and the outer peripheral surface, and inside the through hole on the outer peripheral surface side of the retainer, The retainer has a slope portion that abuts rotatably, and the opening angle of the retainer with respect to the center of the tip spherical portion of the rod is set to approximately twice the opening angle with respect to the center of the tip spherical portion of the rod of the outer peripheral member. I do. In the above-described configuration, the retainer is composed of a plurality of divided bodies that are divided in a direction perpendicular to the outer circumference, and the divided bodies are provided with through holes that hold a large number of rolling elements so as to freely roll. It is characterized by the following. Further, the rod is constituted by a neck supporting the distal end portion and a shaft portion, and the diameter of the distal end portion is set to be approximately twice as large as the diameter of the neck portion.

[0005]

Since the distal end of the rod is fitted to the outer peripheral member through the retainer holding the rolling element without any gap, there is no backlash, and the distal end of the rod and the outer peripheral member are rolled. Because of the contact, a smooth turning motion is obtained. Furthermore, since the diameter of the neck connected to the tip of the rod is much smaller than the diameter of the tip of the rod, the neck is attached to the end of the retainer from the position where the rod is supported vertically. The angle until contact, that is, the allowable inclination angle, can be made larger than that of the plain bearing.

[0006]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a spherical bearing according to the present invention. 1 and 2 show a spherical bearing 10. FIG. The spherical bearing 10 holds a rod 11 so as to be pivotable within a predetermined angle range. The rod 11 has a distal end 11 a having a spherical outer shape.
It is supported via a number of steel balls 13 and the cage 1
2 is sandwiched between the first outer peripheral member 14a and the second outer peripheral member 14b, and is integrally fixed by the fastening screw 15.

The rod 11 has a spherical tip 11.
a, a neck 11b, and a shaft 11c,
The size of the diameter is: tip part 11a> shaft part 11c> neck part 11b
There is a relationship. Also, the tip 11a> (the neck 11
b) × 2.

As shown in FIG. 3, the retainer 12 bulges the outer peripheral portion outward in a spherical shape, while the inner peripheral surface
The whole is formed in a cylindrical shape corresponding to the outer peripheral surface of the front end portion 11a, and has a cylindrical tube shape as a whole. The retainer 12 is, for example, a molded body of a well-known engineering plastic, and includes a plurality of divided bodies which are divided in a direction perpendicular to the outer periphery of the cylindrical ring, as described later. In these divided bodies, a plurality of rows (here, three rows) of through holes 16 for holding the steel balls 13 so as to be able to roll freely are provided in a direction perpendicular to the outer periphery.

The first outer peripheral member 14a and the second outer peripheral member 1
4b is an annular shape, and the inner surface 17 is a steel ball 13b.
, A spherical surface is formed so that the distal end portion 11a of the rod 11 comes into contact with the same pressure state and fits and clamps. Also, the first outer peripheral member 14a and the second outer peripheral member 14b
This means that a convex portion 18 is provided on one surface of the first outer peripheral member 14a and a concave portion 19 into which the convex portion 18 of the first outer peripheral member 14a is to be fitted, so that the first outer peripheral member 14a can be stacked in close contact. Has formed. Further, the first outer peripheral member 14a has
A stepped hole 20 for accommodating a head and a screw portion of the tightening screw 15 penetrating from one surface where the convex portions 18 are formed on both sides of the inner side surface 17 to the other surface is formed, while the second outer peripheral member 14b is provided.
A screw hole 21 is threaded.

Here, the cage 12 will be described in more detail. That is, as shown in FIGS. 4 and 5, the retainer 12 includes a first divided body 12a to a sixth divided body 12f divided in a direction perpendicular to the outer periphery. In the first to sixth divided bodies 12a to 12f, the steel balls 1
The through hole 16 for holding the first through sixth divided bodies 12a through 12a
The inner peripheral surface of 2f has an opening slightly larger than the outer diameter of the steel ball 13, while the outer peripheral surfaces of the first to sixth divided bodies 12a to 12f are compared with the diameter d of the steel ball 13. It has a small opening. The thickness t of each of the first to sixth divided bodies 12a to 12f is smaller than the diameter d of the steel ball 13;
When the steel balls 3 are arranged in the through holes 16, the steel balls 13 project from both the inner peripheral surface and the outer peripheral surface. Further, inside the through hole 16 on the outer peripheral surface side of each of the first to sixth divided bodies 12a to 12f, a slope portion 22 is formed, which is in rolling contact with the steel ball 13, and the steel ball 13 is formed from the outer peripheral surface side. I do not get out. In this state, the steel ball 13 contacts the distal end 11a of the rod 11 on the inner peripheral surface side of the first to sixth divided bodies 12a to 12f, and on the outer peripheral surface side, the first outer peripheral member 14a and the second outer peripheral member 14a. It comes into contact with the inner side surface 17 of the member 14b.

Next, the spherical bearing 1 constructed as described above.
0, the dimensional relationship of each component will be described. That is, in the spherical bearing 10, as shown in FIG. 2, the rod 11 moves with respect to the first outer peripheral member 14 a and the second outer peripheral member 14 b which are integrally fixed to each other by the tightening screw 15.
From the state where the rod 11 is supported vertically, the neck 11b
Is in contact with the end of the retainer 12, that is,
It is a structure that can be displaced and inclined to the allowable inclination angle H. In addition, the retainer 12 and the tip 11 of the rod 11
The contact relationship between the first outer peripheral member 14a and the second outer peripheral member 14b is defined by the angle F between the coupling surface of the first outer peripheral member 14a and the second outer peripheral member 14b to the lower end of the retainer 12. The opening angle E from the coupling surface to the end of the inner surface 17, which is the rolling surface of the steel ball 13, of the first outer peripheral member 14 a is set to be approximately twice as large as the center of the tip 11 a of the rod 11. The angle GF between the neck 11a and the retainer 12 is set to be larger than E. That is, a preload is applied between the distal end 11a of the rod 11 and the first and second outer peripheral members 14a and 14b, and the distal end 11
a, the radius of the steel ball 13 and the radius of the steel ball 13 are R and r, respectively, assuming that no slippage occurs between the steel ball 13 and the first and second outer peripheral members 14a and 14b. G =
Since it is ideal to be 3E + 2Er / R, it is sufficient to increase it by 2Er / R.

According to the spherical bearing 10 as described above, it is possible to eliminate a gap by applying a preload, and moreover, a large number of steel balls 1 are required.
The leading end 11a of the rod 11 is fitted to the first and second outer peripheral members 14a, 14b via the third member 3 and is not a so-called sliding bearing as in the conventional case, but a rolling bearing by the steel ball 13, so that the preload is reduced. The movement becomes smooth even when the device is provided. Furthermore, if the standard dimensions are set so as to satisfy G = 3E + 2Er / R and 11a> 2 × 11b, the allowable inclination angle H can be increased, and the tip of the rod 11 without rattling and without falling off. Since the portion 11a can be supported, it can be said that the bearing is more suitable for a precision measuring instrument, a precision processing machine, a precision positioning mechanism, and the like.

[0013]

As described above, according to the present invention, since the rod tip and the outer peripheral member are fitted without any gap by applying a preload through a number of rolling members, there is no backlash and high precision is achieved. It can be said that the bearing is more suitable for the required precision measuring instrument, precision processing machine, precision positioning mechanism and the like.
In addition, since the rod tip and the outer peripheral member come into rolling contact, a smooth turning motion is obtained, and the diameter of the neck connected to the rod tip is much smaller than the diameter of the rod tip. Therefore, the angle from the position where the rod is vertically supported to the point where the neck comes into contact with the end of the retainer, that is, the allowable inclination angle can be made larger than that of the existing slide bearing.

[0014]

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional explanatory view showing one embodiment of a spherical bearing according to the present invention.

FIG. 2 is an abbreviated cross-sectional explanatory view showing an allowable inclination angle of a rod in the spherical bearing shown in FIG. 1;

FIG. 3 is an exploded configuration view of the spherical bearing shown in FIG. 1;

FIG. 4 is an explanatory plan view showing a configuration of a retainer in the spherical bearing shown in FIG. 1;

FIG. 5 is an explanatory view of the arrangement of through holes for holding rolling members in the cage shown in FIG. 4;

FIG. 6 is an abbreviated cross-sectional view showing an example of a current sliding bearing.

FIG. 7 shows another example of a current plain bearing;
It is an abbreviated sectional explanatory view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Spherical bearing 11 Rod 11a Tip 11b Neck 11c Shaft 12 Cage 12a-12f Dividing body 13 Steel ball 14a, 14b Peripheral member 15 Tightening screw 16 Through hole 17 Inner surface 18 Convex portion 19 Recess 20 Stepped hole 21 Screw hole 22 Slope

Claims (3)

(57) [Claims] 1. A spherical bearing for holding a rod so as to be pivotable within a predetermined angle range, wherein said rod has a tip portion having a spherical outer shape, and said tip portion is provided on a retainer with a plurality of rolling elements. And surrounding and supporting the retainer on an outer peripheral member attachable to the apparatus body,
The retainer is provided with a through-hole for rotatably holding a number of rolling elements, and the through-hole for holding the rolling elements is on the inner peripheral surface side of the retainer as compared with the outer diameter of the rolling elements. While the opening is slightly large, the opening is smaller than the outer diameter of the rolling element on the outer peripheral surface side of the retainer, and when the rolling element is disposed in the through hole, the rolling element projects on both the inner peripheral surface and the outer peripheral surface. As described above, inside the through hole on the outer peripheral surface side of the retainer, there is a sloped portion that is in rolling contact with the rolling element, and the opening angle of the rod of the retainer with respect to the center of the spherical end of the rod is set to A spherical bearing characterized in that the angle is set to approximately twice the opening angle with respect to the center of the spherical portion at the tip of the rod. 2. The retainer is composed of a plurality of divided bodies divided in a direction perpendicular to the outer periphery, and through holes are provided in these divided bodies to hold a large number of rolling elements so as to freely roll. The spherical bearing according to claim 1, wherein: 3. The rod according to claim 1, wherein the rod comprises a neck supporting the distal end and a shaft, and the diameter of the distal end is set to be approximately twice as large as the diameter of the neck. 2. The spherical bearing according to 1.