Device for rotatable mounting of work pieces, in particular crankshafts

Abstract

The invention relates to a device for receiving workpieces to be balanced in a machine for performing an unbalance compensation having a bearing device (2) arranged on a machine frame for rotatable mounting of the workpiece (3) around a bearing axis (L), wherein the bearing device (2) has at least one bearing block (10) having two bearing shells (18, 19) differing in diameter and lying adjacent to each other in a direction transverse to the bearing axis (L). The bearing block (10) is movable transversely to the bearing axis (L) of the bearing device (2) into two bearing positions and another one of the two bearing shells (18, 19) is aligned centrally to the bearing axis (L) in each of the two bearing positions.

Claims

1. A device for receiving workpieces to be balanced in a machine for performing an unbalance correction, with a bearing device arranged on a machine frame for supporting the workpiece for rotation about a bearing axis L, wherein the bearing device includes at least one bearing block having two bearing elements differing in diameter and lying next to each other in a direction transverse to the bearing axis, wherein the bearing block is movable transversely to the bearing axis of the bearing device into first and second bearing positions, wherein in each of the first and second bearing positions another one of the two bearing elements is aligned centrally to the bearing axis, wherein the at least one bearing block is adjustable relative to the machine frame in the direction of the bearing axis, wherein the at least one bearing block is arranged on a slide movable along a straight-line guide provided on a slide carrier, and wherein the slide carrier mounts a drive mechanism enabling the slide to be moved into the bearing positions.

2. The device according to claim 1, further comprising a first stop limiting movement of the at least one bearing block relative to the machine frame in a first direction of movement and a second stop limiting movement of the at least one bearing block relative to the machine frame in a second direction of movement, wherein the bearing position of the at least one bearing block is adjustable by the first stop and the second bearing position of the at least one bearing block is adjustable by the second stop.

3. The device according to claim 1, wherein the bearing elements of the at least one bearing block are replaceable bearing shells.

4. The device according to claim 1, wherein the drive mechanism includes a pneumatic working cylinder and a lever transmission to transmit the movement of the working cylinder to the slide.

5. The device according to claim 1, wherein the slide carrier is carried for movement in a straight-line guide arranged on the machine frame parallel to the bearing axis.

6. The device according to claim 1, wherein the machine frame mounts an actuator for moving the slide carrier in the direction of the bearing axis.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be explained in more detail in the following with reference to an embodiment illustrated in the accompanying drawing. In the drawing.

(2) FIG. 1 is a perspective view of a device for receiving and positioning a crankshaft in a machine for performing an unbalance correction;

(3) FIG. 2 is a side view of a unit comprised of bearing block, slide and slide carrier of the device of FIG. 1;

(4) FIG. 3 is a perspective view of the unit of FIG. 2; and

(5) FIG. 4 is a view of a section of the bearing block of FIG. 3 showing a bearing element arranged therein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(6) FIG. 1 shows, as seen looking from above, a plate-shaped upper part 1 of a machine frame mounting a bearing device 2 for supporting a workpiece 3, in this Figure a crankshaft, and a rotary positioning mechanism 4. The upper part 1 includes parallel guide rails 5, 6 forming a straight-line guide on which the bearing device 2 and the rotary positioning mechanism 4 are held and carried for movement in the guide direction.

(7) The bearing device 2 comprises two identical units 2a, 2b in side-by-side arrangement. The units 2a, 2b are movable longitudinally to the guide rails 5, 6 independently of each other. Each unit 2a, 2b includes a plate-shaped bearing block 10, a slide 11 carrying the bearing block 10, and a slide carrier 12 on which the slide 11 is mounted for movement in a straight line. On its underside, the slide carrier 12 is provided with guide elements 13 holding and guiding it on the guide rails 5, 6. On its upper side, the slide carrier 12 includes a guide rail 14 aligned parallel to a plane perpendicular to the guide rails 5, 6. The slide 11 is movably carried on the guide rail 14 by means of guide elements 15.

(8) The plate-shaped bearing block 10 is aligned parallel to a plane perpendicular to the guide rails 5, 6 and has on its upper side two relatively spaced bearings 16, 17 of different size with bearing shells 18, 19.

(9) To move the slide 11 longitudinally to the guide rail 14, the slide carrier 12 mounts a pneumatic working cylinder 20 having its longitudinal axis aligned normal to the plane of movement of the slide carrier 12. The working cylinder 20 has the exit end for its piston rod 21 secured to the underside of the slide carrier 12 by means of an angle bracket 22, such that the piston rod 21, in the extended position shown in the drawing, protrudes upwardly beyond the slide carrier 12.

(10) The end of the piston rod 21 is connected with the end of a two-armed lever 23 of a lever transmission 24 transmitting the movement of the piston rod 21 to the slide 11. For this purpose, the slide 11 includes a fork 25 having its free ends pivotally jointed to the other end of the lever 23. In its middle, the lever 23 is rotatably mounted on the ends of lever supports 26 whose opposite ends are rotatably secured to the slide carrier 12.

(11) The Figures show the slide 11 in its end position with the piston rod 21 extended in which the bearing 16 of the bearing block 10 is in the bearing position for unbalance correction. To move the bearing block 10 into the other bearing position in which the bearing 17 occupies the position of the bearing 16, the piston rod 21 is retracted into the working cylinder 20. As this occurs, the lever 23 and the lever supports 26 are rotated in opposite directions, and the lever 23 moving away from the piston rod 21 pulls the slide 11 close to the piston rod 21. The end position of the slide 11 is defined by a stop screw 28 provided on the slide 11, which makes abutment with the bearing element protruding from the slide carrier 12 for rotatably carrying the lever support 26.

(12) The opposite end position is limited by an adjustable stop screw 29 arranged in an upright end plate 30 of the slide carrier 12.

(13) The rotary positioning mechanism 4 arranged on the upper part 1 is mounted on a slide 32 equally movably carried on the guide rails 5, 6. Arranged on the slide 32 is a spindle housing 33 receiving a rotary positioning spindle 34 capable of being rotated into any presettable angular position by a servo motor 35. The slide 32 mounts in addition a linear drive mechanism 36 which is connected to the slide carrier 12 of the unit 2a by a drive rod 37 and serves to advance the rotary positioning mechanism 4 to the workpiece 3 carried in the bearing device 2 to enable the rotary positioning spindle 34 to be coupled to the workpiece 3.

(14) FIG. 1 shows the bearing device 2 in a position in which the bearing blocks 10 of the units 2a, 2b are at the proper relative distance for receiving the workpiece 3 which in this instance is a crankshaft for a three-cylinder engine, and in which their bearings 16, in the bearing position, are provided with bearing shells the diameters of which correspond to the diameters of the workpiece bearings.

(15) In this position, the bearings 16 of the bearing blocks 10 define with their center points a bearing axis L which coincides with the axis of rotation of the seated workpiece 3. The rotary positioning mechanism 4 is arranged on the upper part 1 such that the axis of rotation of the rotary positioning spindle 34 coincides with the bearing axis L. In this way, it is possible for the rotary positioning spindle 34 to be coupled directly to the flange of the workpiece 3. For unbalance correction, the rotary positioning spindle 34 rotates the workpiece 3 into the prior established correction position. Using a drilling device, not shown, which is arranged above the correction position the unbalance correction can then be performed by the removal of stock from the workpiece 3.

(16) When it is desired to receive in the device a workpiece whose bearings differ in diameter from the workpiece 3, the bearings 17 of the bearing blocks 10 are provided with bearing shells 19 of a bearing diameter suitable for this other workpiece and with center points lying in a plane containing the bearing axis L and arranged parallel to the linear movement of the slide 11. For seating the other workpiece following removal of the workpiece 3, the working cylinders 20 are controlled such that the piston rods 21 are moved into a retracted position, which causes the bearing blocks 10 to be moved into the other position closer to the piston rods 21. In this position of the bearing blocks 10, the bearing axis L now defined by the bearing shells 19 is at the same place as previously the bearing axis L of the bearing shells 18. As described in the foregoing, the workplace held in the bearing shells 19 may then be coupled to the rotary positioning spindle, rotated into the proper position and balanced.

(17) To seat relatively long or short workpieces or workpieces with different spacing between bearings, the units 2a, 2b of the bearing device 2 may be displaced relative to each other longitudinally to the guide rails 5, 6. Such displacement may be accomplished fully automatically by means of actuators, not shown, using predetermined or prior collected position data.

(18) FIG. 4 shows the fastening of a bearing shell 18 in the bearing 16 of a bearing block 10. The bearing shell 18 rests with a cylinder surface concentric with the bearing center in a concentric cylindrical recess 38 of the bearing block 10. Grooves 39 provided at the ends of the bearing shell 18 are engaged by projections 40 formed on a shoulder 41 of the bearing block 10 and on a detachable holding element 42. The projections 40 fixedly hold the bearing shell 18 in axial direction. To replace the bearing shell 18, the holding element 42 held by a screw is removed. The fastening of the bearing shell 19 is constructed in like manner.