DE202016006904U1 - Rotary lifting actuator - Google Patents

Abstract

Rotary-stroke actuator, consisting of a fixed part that can be connected to a machine, and a moving part that hold objects, position along a stroke axis and can orient around a rotation axis.

Description

Technical application

The invention is a positioning system with a linear and an axis of rotation for the delivery and orientation of objects. The main application is in the area "Pick and Place", where z. B. electronic or micromechanical components recorded, positioned, oriented, pressed, contacted, stored and magaziniert. Another field of application is the automatic visual inspection of such components, which are measured and aligned in front of a camera.

• • der Dynamik des Antriebs zum Erreichen möglichst kurzer Positionierzeiten,
• • der Standzeit, um möglichst viele Positionierzyklen innerhalb eines Wartungsintervalls durchlaufen zu können.

The use of these rotary-stroke actuators within automated production processes usually leads to very high demands z. B. with respect

• The dynamics of the drive to achieve the shortest possible positioning times,
• • The service life in order to be able to go through as many positioning cycles as possible within a maintenance interval.

State of the art

There are a number of rotary-stroke actuators known to fulfill these tasks. Due to the high dynamic requirements, the actuators are usually based on electrodynamic drives, ie on the force effect of a magnetic field on a current-carrying conductor. A distinction is made between systems with moving coils and moving magnets.

Lifting and turning movements can also be detected with a measuring system. This means that defined positions and orientations can be approached. Alternatively, the actuators can be operated at a defined force and at a defined torque.

The actuators consist of a fixed part, which is connected to the machine, and a moving part, which holds, positions and orientates the component. The moving part must be stored and guided to the fixed part of the actuator. Are usually used high-precision bearings / bearings or rolling bearings / guides, such. B. ball bearings, ball bushes and profile shaft guides.

Pairings have the disadvantage of relatively high friction, which inhibits the movement of the actuator on the one hand and on the other hand leads to higher energy loss and wear. Pairing has advantages in this respect, but also there is a friction and wear-prone solid state contact. In both cases, lubricants are used which also wear out or degenerate over the period of use.

The recording of the objects to be positioned can be done by various grippers. Vacuuming with vacuum, which is used to pick it up and then turn it off again, is widely used. To grasp the objects, an auxiliary energy or the vacuum must be fed to the moving part of the actuator. The feed device may hinder the movement of the actuator in the direction of rotation and stroke as little as possible. Be used for this z. As flexible hoses and vacuum rotary joints, which have internal sealing surfaces and bearings. Also, these feeders do not come without the friction and wear-prone solid state contact.

Often required by rotary stroke actuators that they move in the de-energized state in a defined position and then remain there. This should be z. B. in the possible error or emergency case of the parent machine unnecessary collision points and unnecessary damage can be avoided. In order to achieve this, springs are sometimes placed between the fixed and movable parts of the actuators. Not infrequently, these springs limit the life of the entire actuators by fatigue fractures.

DE 10 2006 052 455 B4 shows a placement for loading substrates with electrical components with a rotary hub motor. Lifting and rotary actuator are combined or parallel. The lifting actuator has various soft magnetic materials to cause a constant restoring force. Not described are a measuring system for both directions of movement, the execution of the storage and the execution of a holding device.

DE 10 2008 038 758 A1 discloses a comparable arrangement that may include air bearings. A measuring system for both directions of movement and a non-contact transmission of the vacuum required for sucking the components are not provided.

Object of the invention

Invented was a rotary stroke actuator, which must have no friction and wear-prone solid state contacts between the fixed and moving Aktorteil.

approach

• 1. Der bewegliche Teil des Aktors basiert auf einer Hohlwelle (1).
• 2. Die Hohlwelle (1) wird vorn durch ein vorderes Luftlager (2) gelagert.
• 3. Der Hubantrieb (3) funktioniert nach dem elektrodynamischen Prinzip mit bewegten Magneten.
• 4. Sowohl der Hub als auch die Drehung des Aktors werden durch ein Messystem (4) detektiert, dessen Maßverkörperung bewegt wird, während die Signalaufnehmer still stehen.
• 5. Der Drehantrieb (5) funktioniert ebenfalls nach dem elektrodynamischen Prinzip mit bewegten Magneten.
• 6. Die Hohlwelle (1) wird am hinteren Ende durch ein hinteres Luftlager (6) gelagert, das zudem eine berührungsfreie Vakuumdurchführung enthält.
• 7. Der Magnetkreis der Antriebe ist so gestaltet, dass im stomlosen Zustand eine wegabhängige Kraft derart wirkt, dass der bewegliche Teil des Aktors in eine sichere Ruheposition bewegt und gehalten wird.
• 8. Die Hohlwelle (1) wird durch einen Blindstopfen (7) verschlossen.

The object is achieved by the in sketched arrangement solved:

• 1. The moving part of the actuator is based on a hollow shaft ( 1 ).
• 2. The hollow shaft ( 1 ) is forward through a front air bearing ( 2 ) stored.
• 3. The lifting drive ( 3 ) works according to the electrodynamic principle with moving magnets.
• 4. Both the stroke and the rotation of the actuator are controlled by a measuring system ( 4 ) detected, whose measuring scale is moved while the signal sensor stand still.
• 5. The rotary drive ( 5 ) also works according to the electrodynamic principle with moving magnets.
• 6. The hollow shaft ( 1 ) is at the rear end by a rear air bearing ( 6 ), which also contains a non-contact vacuum feedthrough.
• 7. The magnetic circuit of the drives is designed so that in the dead state, a path-dependent force acts such that the movable part of the actuator is moved and held in a safe rest position.
• 8. The hollow shaft ( 1 ) is replaced by a blind plug ( 7 ) locked.

The inventive combination of air bearings, drives with moving magnets, a measuring system with moving material measure and a non-contact vacuum feedthrough a rotary hub actuator is possible, the moving part has no solid contact with the fixed part. Thus, the lack of inhibiting friction minimum positioning times and the lack of solid contact maximum life is possible.

importance

The invention attains significance wherever objects have to be displaced along an infeed axis and rotated about an axis of rotation, and maximum dynamics and minimal wear are required.

embodiment

The embodiment in shows the overall structure of the actuator.

shows the front air bearing ( 2 ). The air bearing body ( 2.1 ) has a very precisely executed air gap to the hollow shaft ( 1 ), into which by an air supply ( 2.2 ) Compressed air flows into the hollow shaft ( 1 ) in the air bearing body ( 2.1 ) wearing. The air bearing body ( 2.1 ) through the air bearing housing ( 2.3 ) held.

shows the lifting actuator ( 3 ). Lifting Actuator Magnets ( 3.1 ) are annular around the hollow shaft ( 1 ) and firmly connected to this. Are the stationary lifting actuator coils ( 3.2 energized, forms a magnetic field, which generates an axial force on the Hubaktormagnete and causes the lifting movement. The lifting actuator coils ( 3.2 ) are in the Hubaktorgehäuse ( 3.3 ) held.

shows the measuring system ( 4 ). It contains on the movable Aktorteil a material measure for the rotation angle ( 4.1 ) as well as a material measure for the stroke ( 4.2 ) of the actuator. The localization or position of the material measures are detected by stationary sensors (not shown). The measuring system is designed in such a way that the part which measures the angle of rotation is insensitive to lifting movements and the part measuring the stroke is insensitive to rotational movements.

shows the rotary actuator ( 5 ). Rotary actuator magnets ( 5.1 ) are annular around the hollow shaft ( 1 ) and firmly connected to this. Are the stationary rotary actuator coils ( 5.2 energized, forms a magnetic field, which generates a torque on the rotary actuator magnets around the axis of rotation and causes the rotational movement. The rotary actuator coils ( 5.2 ) are in the rotary actuator housing ( 5.3 ) held.

The magnetic circuit of one of the two drives can be designed in such a way that a motion-dependent force keeps the movable part of the actuator in a safe rest position in the stomless state. This can z. B. by an asymmetrical structure of Hubaktorgehäuses ( 3.3 ) can be achieved.

shows the rear air bearing ( 6 ). The air bearing body ( 6.1 ) has a very precisely executed air gap to the hollow shaft ( 1 ), into which by an air supply ( 6.2 ) Compressed air flows into the hollow shaft ( 1 ) in the air bearing body ( 6.1 ) wearing. The air bearing body ( 6.1 ) through the air bearing housing ( 6.3 ) held.

The rear air bearing also has a vacuum chamber ( 6.4 ), z. B. can be evacuated by a hose connection. Via a vacuum cross-hole ( 6.5 ) in the hollow shaft ( 1 ) is the interior of the hollow shaft, which by a blind plug ( 7 ) is closed, also evacuated and sucked the object to be positioned. The sealing surfaces of the vacuum chamber can either be formed as an air gap of the air bearing or be decoupled from this by an outlet arranged between the two.

Add to this are optional and not shown are a control unit and the air distribution, air sensors, Vakkumzeugung and distribution. These can be integrated directly into the actuator, depending on the expansion variant, resulting in extremely compact and easily integrated actuator units in machine environments.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102006052455 B4 [0009]
• DE 102008038758 A1 [0010]

Claims (13)

Rotary-stroke actuator, consisting of a fixed part that can be connected to a machine, and a moving part that hold objects, position along a stroke axis and can orient around a rotation axis. Rotary-stroke actuator according to claim 1, characterized in that the bearing of the movable part is designed as an air bearing. Rotary-hub actuator according to one of the preceding claims, characterized in that the lifting drive contained operates on the elecrodynamic principle and contains at least one moving magnet. Rotary-stroke actuator according to one of the preceding claims, characterized in that the rotary actuator contained operates on the elecrodynamic principle and at least one moving magnet detenthes. Rotary lifting actuator according to one of the preceding claims, characterized in that the lifting drive and rotary drive are mounted on a common shaft and their movements can overlap. Rotary lifting actuator according to one of the preceding claims, characterized in that a multi-coordinate measuring system is used for measuring the lifting movement and for measuring the rotational movement. Rotary lifting actuator according to claim 6, characterized in that a measuring system is included with moving material measure. Rotary-stroke actuator according to one of the preceding claims, characterized in that via a vacuum chamber and recesses in the hollow shaft, the closed by a blind plug hollow shaft can be evacuated to suck objects. Rotary-stroke actuator according to claim 8, characterized in that the coupling of the intake vacuum takes place in the moving part without solid state contact. Rotary lifting actuator according to one of claims 8 or 9, characterized in that the sealing of the vacuum chamber takes place via a bearing surface of the air bearing. Rotary-stroke actuator according to one of the preceding claims, characterized in that one of the two electro-dynamic drives normally generates a restoring force that holds the rotary-stroke actuator in a defined rest position. Rotary-stroke actuator according to claim 11, characterized in that the current-setting adjusting force is constant or corresponds to a linear spring characteristic or any other Kurvenverlauft follows. Rotary-hub actuator according to one of the preceding claims, further comprising a control unit and / or an air distribution and / or a Vakkumzeugung and / or a switching unit for switching on and off of the vacuum.

Images