Rotary joint

Abstract

A rotary joint which, in order to limit the mutual rotation of the outer bearing ring (2) with respect to the inner bearing ring (2), is provided with a raceway (11), which is limited by one or two stops (14) and in which a projection connected to the outer bearing ring engages. In order to ensure that a rotation greater than 360° is possible, the raceway is of helical design.

Claims

1. A rotary joint comprising a bearing inner ring, a bearing outer ring, rolling bodies that roll between the bearing rings, a path limiting device that limits a mutual rotation of the bearing outer ring relative to the bearing inner ring and comprises a helical raceway with stops and a tab that projects radially into the raceway circumferentially between the stops.

2. The rotary joint according to claim 1, wherein the helical raceway extends in a direction of a rotational axis (D) of the rotary joint.

3. The rotary joint according to claim 2, wherein the raceway is provided with a plurality of threaded holes and the stops are screwable into the threaded holes.

4. The rotary joint according to claim 3, wherein the plurality of the thread holes are circumferentially arranged around an entire periphery of the raceway.

5. The rotary joint according to claim 2, wherein the bearing inner ring and the bearing outer ring each have two end sides, the rotary joint further comprising a braking device that prevents mutual rotation on the two end sides of the bearing inner ring and the bearing outer ring pointing in a same direction, wherein the braking device includes one of the bearing rings having a brake disk and the other of the bearing rings having a brake pad displaceable in an axial direction against the brake disk.

6. The rotary joint according to claim 1, wherein the rotary joint is for a medical device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 a detail of a rotary joint with braking function,

(2) FIG. 2 a rotary joint with braking function, and

(3) FIG. 3 a side view of a bearing inner ring according to FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) The detail of the rotary joint 1 shown in FIG. 1 is essentially of a bearing inner ring 2 and a bearing outer ring 3, wherein the bearing outer ring 3 coaxially surrounds the bearing inner ring 2. Rolling bodies 4 roll between the bearing inner ring 2 and bearing outer ring 3.

(5) The end sides 5.1 and 5.2 of bearing inner ring 2 and bearing outer ring 3 that point to the left along the rotational axis D in FIG. 1 are provided with a brake device 6. This brake device 6 is formed essentially by a brake disk 7 that is connected to the end side 5.1 of the bearing outer ring 3 and a brake pad 8 that is arranged movable in the axial direction in front of the end side 5.2 of the bearing inner ring 2. Furthermore, a spring 9 is provided that is set into the bearing inner ring 2 and presses the brake pad 8 against the brake disk 7. If the friction lock between the brake disk 7 and brake pad 8 is to be disengaged, an electromagnet 10 also set in the end side 5.2 of the bearing inner ring 2 is energized, which then acts on the brake pad 8, which is made at least partially from ferromagnetic material, and moves this brake pad to the right in FIG. 1.

(6) The rotary joint 1 shown in FIG. 2 is also provided with a brake device 6 that provides for a mutual, temporary fixing of the bearing inner ring 2 relative to the bearing outer ring 3 and corresponds to the brake device 6 according to FIG. 1.

(7) It can be clearly seen from the representation in FIG. 2 that a helical raceway 11 is formed on the bearing inner ring 2. For the sectional view selected in FIG. 2, this is visible especially in the lower part of the bearing inner ring 2 in the figure, where two sections 12 of the single-track raceway 11 are arranged one next to the other in the axial direction.

(8) The helical form of the raceway 11 is also especially clear in FIG. 3 that shows a bearing inner ring 2 according to FIG. 2 in side view. There it is also visible that, for the axial extent of the helical form of the one-track raceway 11, with a view in the direction of the rotational axis D, the raceway 11 is at least partially covered.

(9) As further shown in FIG. 2, a plurality of holes open into the raceway 11, wherein these holes are formed as threaded holes 13. A stop 14 in the form of a threaded pin is screwed into one of these threaded holes 13. The length of this threaded pin is dimensioned so that this projects in the screwed-in state into the raceway 11 (not shown in FIG. 2). Only for the sake of completeness it is noted that another stop 14 in the form of a threaded pin is also present, which, however, is not visible due to the section view in FIG. 2.

(10) A tab 15 connected to the bearing outer ring 3 also engages in the raceway 11, wherein this tab is arranged in FIG. 2 on a slide 15.1. To guarantee that the tab 15 or the slide 15.1 can follow the path specified by the helical raceway 11 extending in the axial direction for the rotation of the bearing outer ring 3 and bearing inner ring 2, the tab 15 or the slide 15.1 is arranged in a guide 16 that allows the tab 15 or the slide to move in the axial direction in the bearing outer ring 3.

(11) While the embodiments here show rotary joints 1 with a brake device 6, this brake device 6 is not absolutely required. Instead, the helical raceway 11 could also be inserted into a rotary joint that has no brake device 6 in another, not shown embodiment.

(12) Rotary joints 1 according to the invention can be especially advantageous in medical technology, for example, for use in rotating mounts for examination tables or ceiling stands.

LIST OF REFERENCE NUMBERS

(13) 1 Rotary joint 2 Bearing inner ring 3 Bearing outer ring 4 Rolling body 5.1, 5.2 End side 6 Braking device 7 Brake disk 8 Brake pad 9 Spring 10 Electromagnet 11 Raceway 12 Section 13 Threaded hole 14 Stop 15 Tab 15.1 Slide 16 Guide