JP3452256B2 - 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 which is a mechanical element related to a bearing that pivots around three orthogonal axes and is applicable as a joint for connecting parallel mechanisms.

[0002]

2. Description of the Related Art Conventionally, a rod having a spherical tip portion, a housing having an inner surface formed with a spherical concave portion for accommodating the spherical tip portion of the rod, and a gap between the spherical tip portion and a spherical concave portion in the housing. There is known a rolling type three-degree-of-freedom rotating pair (hereinafter, spherical bearing) constituted by a retainer that holds a large number of balls interposed therebetween.

[0003]

In such a spherical bearing, although it has high accuracy and high rigidity, when it is swiveled around the shaft portion connected to the spherical tip portion, the relative positional relationship between the retainer, the spherical tip portion and the housing is obtained. Has the drawback that it changes significantly. The present invention has been proposed in order to improve such an inconvenience, and the relative positional relationship between the retainer, the spherical tip end, and the housing changes significantly when the retainer, the spherical tip end, and the housing are swung around the shaft portion connected to the spherical tip end. It is an object of the present invention to provide a spherical bearing that is free from the above.

[0004]

In order to solve the above-mentioned problems, according to the present invention, in claim 1, a retainer in which a rod having a spherical tip portion holds a large number of rolling elements through the spherical tip portion is provided. In a spherical bearing in which the retainer is mounted on a housing while being surrounded and supported by the retainer, and the rod can be swung within a range of a predetermined angle through the retainer, the rod is inserted into the spherical tip portion, The rod is rotatably held around the rod axis via bearing means in the vicinity of the rod loading side in the spherical tip and the tip of the rod, and the spherical tip is pierced in the radial direction, and A pin is provided so as to be orthogonal to the axial direction of the rod, and the pin is in a direction orthogonal to the longitudinal side with respect to the receiving opening surface of the retainer that receives the spherical tip end portion through the rod. Is directed to inserted into the elongated hole formed proposes the pin shaft around the rod, the spherical bearing in which a displaceable around the axis perpendicular to the pin axis. Further, according to the present invention, in claim 2, the rod having the spherical tip portion is surrounded and supported by the retainer holding a large number of rolling elements via the spherical tip portion, and the retainer is attached to the housing to retain the retainer. In a spherical bearing in which the rod can be swung within a range of a predetermined angle through the rod, the rod is loaded in the spherical tip portion, and bearing means is provided in the spherical tip portion near the rod loading side and the tip of the rod. The rod is rotatably held around the rod axis, and the housing is provided with a pin.
The spherical tip of the retainer through the rod.
In the direction orthogonal to the long side of the receiving opening surface
Insert the rod into the elongated hole formed by pointing it
We propose a spherical bearing that is displaceable around the pin and orthogonal to the pin axis .

According to the first aspect, when the rod turns, the rod is rotated about the rod axis by the bearing means inside the spherical tip portion, and the retainer follows the tilting movement of the rod.

According to the second aspect, when the rod rotates, the rod rotates about the rod axis by the bearing means inside the spherical tip portion, and the rod spherical tip portion rotates about the axis with respect to the housing. Since the retainer does not rotate, the retainer receives no force around the shaft due to the protrusion in the housing, and the retainer merely follows and displaces in response to the tilting movement of the rod.

According to the third aspect, the rod can be displaced around the axis of the protrusion.

According to the fourth aspect, the rod can be displaced around the axis of the protrusion fitted in the elongated hole, while the rod can be displaced so that the protrusion extends along the forming direction of the elongated hole.

According to the fifth aspect, regardless of the structure of the main body of the apparatus, the degree of freedom in installing the apparatus is high.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a spherical bearing according to the present invention will be described below with reference to the accompanying drawings by way of one embodiment. FIG. 1 shows a spherical bearing 1. The spherical bearing 1 has a structure in which a rod 2 is held by a housing 3 via a retainer 4 so as to be rotatable within a predetermined angle range. The rod 2 has a spherical tip portion 2a having a spherical outer shape, and the spherical tip portion 2a is held by the retainer 4 via a large number of steel balls 5. Further, a male screw portion 2b is provided on the proximal end side of the rod 2 so that the rod 2 can be screwed into and mounted on an apparatus main body (not shown).

The spherical tip 2a of the rod 2 is
The diameter of the rod 2 is set to be at least twice the diameter of the rod 2, and the rod 2 is supported in a vertical state with respect to the housing 3 integrally fixed to each other by tightening means (described later). Is a structure capable of displacing and tilting to an angle until the end contacts the end of the housing 3. In addition, the spherical tip portion 2a is provided with pins 6, which penetrate the spherical tip portion 2a in the radial direction and are orthogonal to the axial direction of the rod 2.
6 is projected. These pins 6 and 6 are inserted into elongated holes (described later) formed in the retainer 4. And
The rod 2 is inserted into the spherical tip 2a,
The rod 2 is held near the tip of the rod 2 and in the vicinity of the rod 2 loading side in the spherical tip 2 a via bearing means 7, 7.

The contact relationship between the retainer 4 and the spherical tip 2a of the rod 2 is determined by the angle from the connecting surface of the housing 3 (described later) to the lower end of the retainer 4 and the connecting surface of the housing 3. It is set so that an appropriate relationship is established between the opening angle of the housing 3 up to the end of the inner surface 8 which is the rolling surface of the steel ball 5.

The housing 3 is the first housing 3
a and the second housing 3b, and the first housing 3a and the second housing 3b are integrally fixed by a fastening means, that is, a fastening screw 9. The inner side surfaces 8 formed on the first housing 3a and the second housing 3b contact the spherical tip portion 2a of the rod 2 with the retainer 4 via the steel ball 5 in an equal pressure state, and hold the fitting together. The spherical surface is processed so that Further, the first housing 3a is formed with an opening portion 10 which is continuous with the inner side surface 8 and has an inclined edge E for determining a swing allowable range of the rod 2, while the second housing 3b side is also provided with an inner side surface. A cylindrical opening 11 is formed so as to be continuous with 8.

Next, the retainer 4 has its outer peripheral portion bulging outward in a spherical shape, while its inner peripheral surface is formed in a spherical shape corresponding to the outer peripheral surface of the spherical tip portion 2a of the rod 2. It has a spherical shape with the facing surfaces opened. Further, the retainer 4 is, for example, a well-known molded body of engineering plastic, and has a surface formed by opposed openings,
That is, the receiving opening surface 12a that receives the spherical tip portion 2a via the rod 2 of the rod 2 and the receiving opening surface 1
It is divided into first and second horizontal division bodies 4a and 4b in parallel with the opening surface 12b facing 2a (see FIGS. 2 and 3), or the first opening is divided into the receiving opening surface 12a and the opening surface 12b. The first and second vertical divisions 4c and 4d can be divided (see FIG. 4). In the divided body of the retainer 4, through holes 13 that hold the steel balls 5 in a rollable manner are concentrically arranged with respect to the centers of the receiving opening surfaces 12a and 12b in a plurality of rows at equal angles. The through hole 13 has an opening on the inner surface side of the split body of the retainer 4 which is slightly larger than the outer diameter of the steel ball 5, while the outer circumferential surface side of the split body is on the outer diameter of the steel ball 5. It has a small opening in comparison. In this state, the steel ball 5 comes into contact with the tip portion 2a of the rod 2 on the inner peripheral surface side of the divided body, and contacts the inner side surface 8 of the housing 3 on the outer peripheral surface side. When the spherical tip 2a of the rod 2 is held through the steel ball 5, the retainer 4 is provided with elongated holes 14 through which the pins 6 protruding from the spherical tip 2a are inserted.
14 is formed. In this case, the long holes 14, 14 are
The retainer 4 is oriented in a direction orthogonal to the receiving opening surface 12a and the opening surface 12b.

In the spherical bearing 1 as described above, while the housing 3 side is attached to the movable member (not shown) side,
The operation when the male thread portion 2b side of the rod 2 is attached to the apparatus body will be described. In addition, conversely, the operation when the male screw portion 2b side of the rod 2 is attached to the movable member and the housing 3 side is attached to the apparatus main body is similar, and therefore the description of this structure is omitted. First housing 3a and second housing 3
b is screwed into the first housing 3a side from the second housing 3b side with the tightening screw 9 to fix the housing 3 integrally, and the housing 3 side is attached to the movable member.

Now, when the movable member is displaced relative to the main body of the apparatus, the rod 2 is pivotally displaced relative to the housing 3 side. At that time, the operating range of the rod 2 is determined by the inclined edge E of the opening 10 in the first housing 3a. Following the movement of the rod 2, that is, the movement of the spherical tip portion 2a, the retainer 4 moves the inner surface 8
The receiving opening surface 12a and the opening surface 12b of the retainer 4 project and retract from the opening 10 in the first housing 3a and the cylindrical opening 11 in the second housing 3b by moving and displacing through the steel ball 5.

Here, too, the rod 2 is attached to the housing 3
On the other hand, when the spherical tip 2a is displaced about the axis passing through the pins 6 and 6 and along a plane orthogonal to this axis,
The pins 6 and 6 of the spherical tip portion 2a do not hit the side surfaces of the elongated holes 14 and 14 of the retainer 4,
The pins 6 and 6 move along the long holes 14 and 14,
The retainer 4 is appropriately displaced in accordance with the movement of the rod 2 simply by rotating around the axis penetrating the pins 6 and 6 in the elongated holes 14 and 14.

On the other hand, in the case where the rod 2 swings with respect to the housing 3 around the axis penetrating the pins 6 and 6 in the spherical tip portion 2a and the plane orthogonal to this axis, the rod 2 is placed in the spherical tip portion 2a. The loaded rod 2 has the bearing means 7, 7
The rotation of the retainer 4 causes the retainer 4 to be displaced in accordance with the movement of the rod 2 only by inclining the rod 2 with respect to the housing 3.

The spherical bearing according to the present invention can be implemented as follows. That is, although not shown in the drawings, the pins 6, 6 protruding from the spherical tip 2a of the rod 2 are provided.
Can be provided on the housing 3 side from the inner side surface 8 toward the center of the spherical tip 2a.

The spherical bearing according to the present invention may have a structure in which a pair of rods 2 and 2 are provided so as to be in a straight line so as to sandwich the spherical tip 2a. With such a structure, the degree of freedom of attachment to the apparatus main body is increased, and accordingly, it is possible to greatly contribute to the apparatus having various functions.

[0021]

As described above, according to the present invention, the retainer can be made to follow the movement of the rod, and the relative positional relationship between the retainer, the spherical tip portion, and the housing does not greatly change, and thus the rod is not changed. It can be said that the bearing is suitable for precision measuring instruments, precision machining machines, precision positioning mechanisms, etc., which require no high backlash in the supported state.

[0022]

[Brief description of drawings]

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

FIG. 2 is a cross-sectional explanatory view of the retainer in the spherical bearing shown in FIG. 1, taken in a direction that divides an elongated hole of the retainer.

3 is an explanatory plan view of the retainer shown in FIG. 2. FIG.

FIG. 4 is a cross-sectional explanatory view of the retainer in the spherical bearing shown in FIG. 1, taken from another direction.

[Explanation of symbols]

1 Spherical bearing 2 rod 2a spherical tip 3 housing 3a first housing 3b Second housing 4 retainer 5 steel balls 6 pin 7 Bearing means 8 inner side 9 Tightening screw 10 openings 11 Cylindrical opening 12a receiving opening surface 12b Opening surface 13 through holes 14 slot

Continuation of the front page (56) References JP-A-8-338422 (JP, A) JP-A-6-249232 (JP, A) JP-A-2000-304039 (JP, A) Actual development Sho-57-182632 (JP, U) Actual development Sho 49-136937 (JP, U) Actual public Sho 33-4912 (JP, Y1) Actual public Sho 18-3907 (JP, Y1) Utility model registration 338613 (JP, Y2) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16C 11/06-11/08 F16C 23 / 04,23 / 08

Claims (2)

(57) [Claims] 1. A rod having a spherical tip portion is surrounded and supported by a retainer holding a large number of rolling elements through the spherical tip portion, and the retainer is mounted on a housing, and the rod is attached through the retainer. In a spherical bearing that can rotate within a range of a predetermined angle, the rod
Is loaded into the spherical tip and the
Via bearing means in the vicinity of the loading side and the tip of the rod.
The rod to be rotatable about the rod axis.
The spherical tip so that it penetrates radially and
Pin so that it is orthogonal to the axial direction of the
The spherical tip of the retainer through the rod.
In the direction orthogonal to the long side of the receiving opening surface
Insert the rod into the elongated hole formed by pointing it
A spherical bearing characterized in that it is displaceable around the axis orthogonal to the pin axis . 2. A rod having a spherical tip portion is surrounded and supported by a retainer holding a large number of rolling elements through the spherical tip portion, and the retainer is mounted on a housing, and the rod is attached through the retainer. In a spherical bearing which can be swung within a range of a predetermined angle, the rod is loaded into the spherical tip portion, and the rod is inserted through bearing means in the vicinity of the rod loading side in the spherical tip portion and the tip of the rod. was configured to turnably held to the rod axis around, the pin is provided on the housing, the pin, the
Retainer accepts spherical tip through rod
Orient the long side in a direction orthogonal to the receiving opening surface
Inserted through the elongated hole formed by, the rod around the pin axis,
A spherical bearing characterized by being displaceable around an axis orthogonal to the pin axis .