EP2423151B1 - Rotary encoder assembly with radial clearance compensation - Google Patents

Description

The invention relates to a radial play compensating Drehwinkelgeberanordnung for the crane slewing connection, in particular for a rotary connection to working machines, in particular for a ball slewing connection or roller slewing connection between the upper and lower chassis of a mobile crane.

The turntable of a superstructure is usually rotatably connected to a mobile crane via a ball slewing or roller slewing with the undercarriage. If the rotary connection is not exactly centered on the turntable, a certain radial tolerance between the rotary joint and turntable may occur during the initial assembly of the rotary joint on the turntable. If a rotary encoder is arranged on the turntable of the superstructure, it then comes to the intervention of the rotary encoder on the rotating ring gear of the rotary joint also to an unwanted radial tolerance. In the prior art, therefore, assigns the rotary encoder at one end of a bendable arm, which is fixed at its other end to the turntable of the superstructure and holds the rotary encoder under bias to the sprocket. The elastic deformation of the bendable arm compensates the radial tolerance. Since the rotary joints have very large diameters, it often comes due to manufacturing tolerances to tolerances in the concentricity of the ring gear, which are also compensated by the bendable arm.

A rotary encoder mounted on one end of a bendable Am is in document DE 10 2004 022 770 A1 disclosed.

However, when turning the superstructure, the bendable arm projecting beyond the turntable can be easily damaged together with the rotary encoder, for example by lifting means such as belts or chains deposited on the undercarriage, which hang on the arm and bend it.

The present invention is therefore an object of the invention to provide a rotary encoder, which compensates for the radial play occurring at the rotary joint and at the same time avoids damage to the rotary encoder.

This object is achieved by the subject of the protection claim 1. The dependent claims define preferred embodiments of the present invention.

The rotary encoder arrangement according to the invention is provided for a crane turning connection, which allows a rotation between two rotary elements, for example a top and an undercarriage of a mobile crane. However, it would of course be possible to apply the basic idea of the invention to other rotary joints, in particular to rotary joints on any mobile machines.

The rotation angle sensor arrangement according to the invention comprises an elastic rolling element, which rotates coupled to the rotary encoder via its peripheral surface on the first rotary element, the rotary encoder detects the rotational movement about the axis of rotation of the rolling element and the rolling element is held translationally and / or rotationally adjustable by the second rotary member by means of a bearing, so as to vary the distance of the rolling element to the first rotary element.

In other words, the rotation angle sensor arrangement comprises a rolling element which can be deformed in the elastic region, which, for example, like a friction wheel, can have a smooth circumferential rolling surface. To avoid slippage between rolling element and rotating element, however, it may also have a toothing or the like. This rolling element rolls over its peripheral surface on a corresponding surface of a first rotary member and is thereby supported or supported by a second rotary member, which is relative to the first Rotary element is rotationally movable. The axis of rotation of the rolling element is fixed to the second rotary element and the rotational movement of the rolling element is transmitted to a rotary encoder, so that the Abrollweg the rolling element can be determined.

According to the present invention, the rolling element is not supported directly by the first rotary member, but rather a bearing is provided, which is interposed between the rolling element and the rotary element and so coupled rolling element and second rotary element to each other. This storage allows rotation and / or translation of the rolling element relative to the first rotary element. In this way, the distance between the rolling element and the first rotary element can be changed.

Preferably, however, the rolling element is held by means of a substantially disposed within the first rotary member storage and thus protected from damage.

More preferably, the bearing supports the rolling element so that it can be rotated about a different axis of rotation of the rolling element second axis of rotation. Since the second axis of rotation is not different from the first axis of rotation caused by the rolling movement of the rolling element, a change in distance between the rolling element and the first rotary element, on which the rolling element rolls off, results when the rolling element is rotated about the second axis of rotation.

As a result of this change in distance, according to the present invention, the elastic rolling element is pretensioned with respect to the first rotary element or the sprocket. Subsequently, only by any manufacturing / assembly tolerances of the rotary joint or the ring gear of the rotary joint must be compensated. According to the present invention, this is done by the elastic rolling element, which compensates to a certain extent concentricity tolerances, while the axis of rotation of the rolling element relative to the turntable / second Rotary element does not change its position and orientation. It can therefore be said that the present invention provides a double radial tolerance compensation, wherein coarse adjustment takes place by rotating the rolling element in the bearing about the second axis of rotation and the tolerances caused by the manufacture of the rotary joint or the ring gear of the rotary joint by the elastic configuration of the rolling element be compensated.

According to a preferred embodiment of the present invention, the rolling element is a pinion which engages and rolls in the peripheral teeth of a rotary joint sprocket on the first rotary member. The advantage of a corresponding toothing of pinion and ring gear is that no slip between the rolling element and the first rotary element with the ring gear and consequent measurement inaccuracies must be feared.

According to a further preferred embodiment of the present invention, the second axis of rotation extends parallel to the axis of rotation of the rolling element about which the rotation caused by the rolling takes place. Consequently, the movement which the rolling element performs by turning about the second axis of rotation is directed perpendicular to the first axis of rotation and, if the peripheral surface of the rolling element is aligned parallel to the first axis of rotation, also perpendicular to this peripheral surface. Furthermore, it is possible for the second axis of rotation to be parallel to the axis of rotation between the first and second rotary elements, so that the movement which the rolling element makes when rotating about the second axis of rotation is perpendicular to the axis of rotation between the rotary elements, and if so corresponding rolling surface or toothing on the second rotary element / undercarriage runs parallel to the axis of rotation between the rotary elements, also perpendicular to this rolling surface or sprocket teeth of the undercarriage. Run all three axes of rotation parallel, so the rolling element when turning about the second axis of rotation perpendicular to the axes of rotation in the outer teeth of the ring gear on or extended, so that in this way any radial play can be compensated in a simple manner. This is according to the present invention after assembly of the Rotary connection made on the turntable, wherein the desired position of the rotary encoder is then fixed, so that the rotary encoder from this time is positionally correctly adjusted to the rotary joint. Therefore, in the present invention, to compensate for large tolerances, the rotary encoder need not be attached to a fault-prone bendable arm.

To compensate for further smaller tolerances, the elastic rolling element may comprise an elastic material according to another preferred embodiment. This can be about an elastic plastic, in particular rubber. The rolling element can in this case be made entirely of elastic material, so that there is a kind of rubber gear. On the other hand, it would also be possible to form the rolling and peripheral surface or the rolling toothing on an inelastic element, which surrounds an elastic element circumferentially. In this way, the rolling surface or toothing of the rolling element can be made hard, pressure and wear-resistant, without losing the elastic properties of the rolling element as a whole. This is particularly advantageous when the risk of icing on tooth profile surfaces are to be feared. The inelastic element can be configured as a ring, in which a toothing is incorporated and which rotates a rubber element as an insert. The internal elastic member then couples the inelastic ring member to a drive member of the rotary encoder to relay the rotation of the rolling member to the rotary encoder.

Preferably, the bearing comprises a receptacle for an eccentric, wherein the bearing itself may be formed on or in the second rotary member. The accommodated eccentric then supports the rolling element so that the axis of rotation of the rolling element in the eccentric is different from the axis of rotation of the eccentric in the receptacle of the rotary element.

In particular, the receptacle may be a through-hole in the second rotary element or in the turntable of a mobile crane. In this embodiment, the storage and thus also the rolling element sits more or less in the massively built Turntable and is advantageously no longer so vulnerable to damage outside the turntable attached to a bendable arm.

According to a further preferred embodiment of the present invention, the eccentric supports the rolling element coupled to the rotary encoder together with the rotary encoder itself, in such a way that the eccentric circumferentially surrounds the rotary encoder and holds.

In principle, however, it would also be conceivable if the rotary encoder is arranged at a location other than on or in the storage and receives the rotational movement of the rolling element via a drive element, for example via a rigid or flexible shaft.

In order to fix the desired position of the rolling element and, if necessary, the rotary encoder relative to the first rotary element or ring gear of the undercarriage after assembly and subsequent positioning of the rotary encoder, the Drehwinkelgeberanordnung invention may comprise a locking device with which the adjustable support of the rolling element and, if necessary. the Drehwinkelgebers can be locked, so that no further rotation of the rolling element and, if necessary. The rotary encoder to the second axis of rotation is possible. Also, the rolling element can thereby be biased play-balancing with a certain force against the sprocket, which is made possible by the use of an elastic rolling element.

It is also conceivable that the locking device comprises a clamping ring which is screwed to the eccentric and thereby clamps a clamping ring between the eccentric and arranged, elongated holes for screwing and fixed to the second rotary element base. Once the desired position of the rolling element has been adjusted relative to the first rotary element, the screw is tightened from clamping ring to eccentric and clamps a base between clamping ring and eccentric, wherein the base itself firmly connected to the turntable, for example, can be screwed. By the Screwing between the clamping ring and eccentric is guided in slots of the base, a simple adjustment of the rotary encoder arrangement is possible.

The present invention is based on an embodiment of the FIGS. 1 to 4 explained in more detail. The invention may include features shown here individually as well as in any meaningful combination.

Fig.1

eine Seitenansicht der erfindungsgemäßen Drehwinkelgeberanordnung im eingebauten Zustand

Fig. 2

die Ausführungsform aus Figur 1 in einer perspektivischen Ansicht

Fig. 3

die Ausführungsform aus Figur 1 in einer Draufsicht

Fig. 4

die Ausführungsform aus Figur 1 im aus der Figur 3 ersichtlichen Schnitt

Show it:

Fig.1

a side view of the rotary encoder assembly according to the invention in the installed state

Fig. 2

the embodiment of FIG. 1 in a perspective view

Fig. 3

the embodiment of FIG. 1 in a top view

Fig. 4

the embodiment of FIG. 1 im out of the FIG. 3 apparent cut

In the FIG. 1 a turntable 2 of a superstructure and a ring gear 1 of a lower carriage is shown, wherein the turntable 2 about the rotational axis D relative to the ring gear 1 is rotatably movable. If such a rotation takes place, the screwed firmly on the turntable 2 Drehwinkelgeberanordnung is moved in its storage 5 about the rotation axis D, wherein the rolling element 3 rolls with its peripheral surface 3 a on a corresponding peripheral surface 1 a of the ring gear 1. The peripheral surfaces 1a and 3a are in this case corresponding Stirnradverzahnungen.

The rolling element 3 rotates about the axis of rotation R and is screwed to the rotary encoder 4 so that only a rotational movement about the axis R is possible. The housing of the rotary encoder 4 is firmly held by the eccentric 10. It can also be seen that the turntable 2 also has a through hole 9, in which the eccentric 10 is embedded. By means of the screw 14, the base 15 is clamped by the clamping ring 12 and the eccentric 10, so that the eccentric together with the clamping ring 12 relative to Base 10 can not be twisted. Since the base 15 is screwed to the turntable 2, and the eccentric is fixedly mounted in the turntable 2.

The FIG. 2 shows a perspective view of the rotary encoder assembly with the eccentric 10, the base 15, which is rotatable about the rotation axis R rolling element 3 with the circumferential toothing 3A. Also to be seen is the screw 8 of the elastic rolling element 3, wherein a further not designated inelastic disc allows the screwing of the elastic rolling element 3 to the input shaft of the rotary encoder.

From the FIG. 3 , a plan view of the Drehwinkelgeberanordnung invention is the eccentricity e between the first axis of rotation about which the rolling element 3 rotates when rolling over its teeth 3A, and the second axis of rotation E, by which the eccentric 10 can rotate in the bore 9, unless this is clamped against rotation with the clamping ring 12 and the screw 14 on the base 15. Also visible are the elongated holes 13, which allow a rotation of the eccentric together with the clamping ring 12 and the screw 14, if the screw 14 has been solved.

From the FIG. 4 is a sectional view along AA from the FIG. 3 to see. In particular, it can still be seen that the rolling element 3 here has no inelastic, circumferential ring, but the elastic part 7 extends to the rolling teeth 3A and comes into direct contact with the teeth 1A of the ring gear. Furthermore, it can be seen that the housing of the rotary encoder has a kind of key surface which engages in a further not designated corresponding holding surface of the eccentric 10 and prevents rotation of the rotary encoder 4 relative to the eccentric 10. This is supported by a further unspecified screw.

Claims (11)

1. A rotary position transducer array for a rotary connection on a work machine, in particular for a crane rotary connection, between two rotary elements (1, 2), comprising an elastic roll-off element (3) which, coupled to the rotary position transducer (4), rolls off on the first rotary element (1) via its circumferential area (3a), wherein the rotary position transducer (4) detects the rotational movement about the rotational axis (R) of the roll-off element (3), and the roll-off element (3) is held, such that it can be translationally and/or rotationally adjusted, by the second rotary element (2) by means of a bearing (5), so as to vary the distance between the roll-off element (3) and the first rotary element (1).
2. The rotary position transducer array according to Claim 1, wherein the roll-off element (3) is held such that it can be adjusted about a second rotational axis (E), which is different from the rotational axis (R), by means of a bearing (5) which is in particular arranged substantially within the first rotary element (1).
3. The rotary position transducer array according to Claim 1 or 2, wherein the roll-off element (3) is a pinion (3) which engages the circumferential toothed gearing (1a) of a rotary connection toothed ring on the first rotary element (1) and rolls off on it.
4. The rotary position transducer array according to Claim 2 or 3, wherein the second rotational axis (E) is aligned parallel to the rotational axis (R) of the roll-off element (3) and/or parallel to the rotary axis (D) between the first and second rotary elements (1, 2).
5. The rotary position transducer array according to any one of Claims 1 to 4, wherein the roll-off element (3) comprises an elastic material, in particular a synthetic material, specifically rubber.
6. The rotary position transducer array according to Claim 5, wherein the circumferential area (3a) of the roll-off element (3), which is in particular part of an inelastic annular part, is coupled to a drive element (8) by means of an elastic element (6), in particular an inlay (6), wherein the drive element (8) transmits the rotational movement of the roll-off element (3) onto the rotary position transducer (4).
7. The rotary position transducer array according to any one of Claims 1 to 6, wherein the bearing (5) comprises a receptacle (9) for an eccentric (10) on or in the second rotary element (2), wherein said receptacle (9) supports the eccentric (10) about the second rotational axis (E), and wherein the eccentric (10) supports the roll-off element (3) about the rotational axis (R) of the roll-off element (3).
8. The rotary position transducer array according to Claim 7, wherein the receptacle (9) is a transit bore in the second rotary element (2), in particular in the turntable (2).
9. The rotary position transducer array according to Claim 7 or 8, wherein the eccentric (10) supports the roll-off element (3), which is coupled to the rotary position transducer (4), by means of the rotary position transducer (4), and in particular wherein the eccentric (10) circumferentially encompasses the rotary position transducer (4).
10. The rotary position transducer array according to any one of Claims 1 to 9, wherein the bearing (5) comprises a fixing device (11) using which the adjustable mounting of the roll-off element (3) can be locked in position.
11. The rotary position transducer array according to Claim 10, wherein the fixing device (11) comprises a clamping ring (12) which is screwed to the eccentric (10) and thus clamps a base (15) which is arranged between the clamping ring (12) and the eccentric (10), comprises elongated holes (13) for the screw connection (14) and is fixed to the second rotary element (2).

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