DD293697A5 - LOAD COMPENSATION FOR VERTICALLY MOVABLE LOADS - Google Patents

Abstract

The invention relates to a load balance for vertically movable loads in loading and processing machines, z. As handling devices and industrial robots in which loads in the vertical direction to accelerate, brake and hold in a defined position. It is essential to the invention that the stator of a three-phase linear motor (DLM) is guided on a carrier system as a secondary rail by means of guide rollers via a flexible element via a deflection roller, with a further movable part of a linear module, with a corresponding tool, d. H. a movable load is in WV. For acceleration, a servomotor is coupled to the DLM, with the exact position positioning primarily via a brake and secondarily via an associated electronic position control. The flexible element has a balancing effect. There is predominantly an angle of 90 between the stator, which can also be moved on two opposite secondary rails, and the movable load. The invention is best illustrated in FIG. Fig. 3 {three-phase linear motor (DLM); Traegersystem; Sekundaerschiene; guide roller; flexible element; deflection roller; Linear actuator; movable load; Servomotor; Acceleration; electronic position control; Brake; Stator; Corner}

Description

Explanation of the essence of the invention

The invention has for its object to develop a simple compact load balancing, especially for vertically movable loads, waiving additional drive media, the operation of two electric motors is coupled and support them in accelerating the load.

According to the invention the object is achieved in that a stator of the DLM, which is guided by means of guide rollers on a support system, which is a secondary rail for the DLM and which is arranged at an angle to the direction of action of the movable load and in a required for optimal thrust Actual distance is, by a guided over a pulley flexible element with a movable part of a linear module and thus in operative connection with the movable load, with a directed acceleration of the thrust force on the movable load in connection with a servomotor, and that the DLM over a brake is coupled to the carrier system, with exact positioning of the movable load via an electronic position control of the servomotor with correction options by the flexible element. Furthermore, the stator of the DLM is arranged via guide rollers in the carrier system, which is at an angle of about 90 ° to the movable load, and the operative connection between the stator and the movable load is made above the flexible element, wherein the deflection roller attached to the carrier system is and the stator of the DLM is designed so that it is in contact with two opposite secondary rails. Thus, when the system accelerates, the thrust force of the stator is transmitted almost without loss to the moving load and added to the acceleration force of the actuator located on the fixed part of the linear actuator. If the system is braked, se the stator of the DLM is de-energized and held by a corresponding braking device on the carrier system, while the moving part of the Linearmoc module and thus the moving load is held via an electronic position control of the servomotor in the predetermined 9xakten position, with the purpose necessary correction movements are absorbed by the internal flexibility of the flexible element. Also in this case, the stator of the DLM contributes with the help of the brake for holding the load and the holding force of the servomotor can be reduced accordingly.

embodiment

The invention will be explained in more detail below using an exemplary embodiment. In the accompanying drawings show

Fig. 1: Overall view of the load balance

2 shows a sectional view of the arrangement of the DLM in FIG. 1

Fig. 3: Alternatiwariante the load balance.

1 and 2 consists of a stator 1 of the three-phase linear motor (DLM), which is guided by means of guide rollers 2 on a support system 3 such that for thrust 4 of the stator 1, a favorable effective distance. 5 arises, this carrier system 3 acts simultaneously as a secondary rail 13 for the stator 1. This carrier system 3 is arranged so that its line of action is at an angle, preferably perpendicular to the line of attack of the movable load 6, said load 6 is usually located on the moving part 7 of a vertically arranged linear module. The connection between the stator 1 and the moving part 7 of the linear module by a flexible element 8, z. As a rope manufactured, while this flexible element 8 via a guide roller 9, which is located either on the carrier system 3 or on the fixed part 10 of the linear module out. Thus, an operative connection between the movable load 6 and the stator 1 is produced, whereby on the one hand the required acceleration moments of the DLM are transmitted almost lossless to the movable load 6 and on the other hand there is an internal flexibility, which allows the dos for the exact position determination moving part 7 of the linear module by c'er electronic position control to take corrective movements occur. The use of a plurality of deflection rollers 9 between the stator 1 and the moving part 7 has the consequence that the path and thrust 4 of the stator 1, e.g. can be halved, resulting in further advantages for the structural design of the system.

If the movable load 6 is to be accelerated, first the stator 1 of the DLM is supplied with three-phase current. The force of the DLM is not sufficient to transport the movable load 6. It is the servo motor 11 of the linear module is turned on and the movable load 6 can be accelerated only very quickly, since the forces of DLM and steep motor 11 add up. Upon reaching the predetermined position of the servo motor 11 remains in the electronic position control, the DLM is turned off and at the same time the stator 1 is blocked by a brake 12. Due to the elasticity of the flexible element 8, the electronic position control of the moving part 7 of the vertical linear module is ensured by the servomotor 11. The arrangement according to Figure 3 is based on the same active principle described with the advantage that it is structurally space-saving and can be accommodated within existing elements of a machine system. It should be noted that the guide rollers 2 of the stator 1 of the DLM are arranged so that the required effective distance 5 is made to an inner surface of the carrier system 3. In addition, it is possible with this arrangement to work with two or four opposite secondary rails 13 in order to achieve a better mass-performance ratio.

Claims (3)

1. load compensation for vertically movable loads by means of a three-phase linear motor DLM, characterized in that a stator (1) of the DLM, by means of guide rollers (2) on a support system (3) can be guided, which is a secondary rail (13) represents for the DLM and which is arranged at an angle to the direction of action of the movable load (6) and is in an effective distance (5) required for an optimal thrust force (4), by a via a deflection roller (9) guided flexible element (8 ) is in operative connection with a movable part of a linear module (7) and thus with the movable load (6), with a directed acceleration of the thrust force (4) on the bewegbara load (6) in connection with a servomotor (11), and the DLM is coupled to the carrier system (3) via a brake (12), with exact positioning of the movable load (6) via an electronic position control of the servomotor (11) with correction possibilities by the flexible element ment (8). 2. load compensation according to claim 1, characterized in that the stator (1) of the DLM via guide rollers (2) in a support system (3) which is at an angle of about 90 ° to the movable load (6), is arranged, and the operative connection between the stator (1) and the movable load (6) is produced via the flexible element (8), the deflection roller (9) being fastened to the carrier system (3) and the stator (1) of the DLM being designed that it is in contact with two opposite secondary rails (13). For this 3 pages drawings Field of application of the invention The invention relates to loading and processing machines, for. As handling devices and industrial robots in which loads by means of linear modules or other devices in the vertical direction (z-axis) to accelerate, brake and hold in a defined position, wherein the position reached during deceleration is specified by means of electronic position control exactly , In particular, this is the case with Cartesian portal robots in which one or more axes are arranged vertically. Characteristic of the known state of the art It is known that when operating perpendicularly operating linear modules in the simplest case their standstill under load is achieved in that self-locking gear or mechanical brakes are used. Both methods have the disadvantage that high energy losses occur, which are usually dissipated by heat. In the self-locking gearboxes, whose efficiency is usually below 50%, and thus correspondingly large drive motors must be selected, the associated mass Komenzationen lead just in those areas where lightweight constructions are required, to significant disadvantages. Another possibility is to dispense with such self-locking measures and fully load the selected servomotor when accelerating and braking with the resulting dynamic and static load moments. This has the consequence that correspondingly large servo motors must be selected, which alone by their own weight a kinematic system, such as industrial robots, so heavily burden that its stability is placed at the required positioning accuracies in question. In addition, there is an increased energy consumption. Another way to equalize or compensate for vertically moving loads in their individual positions, is to use as load compensation pneumatic or hydraulic tools (eg working cylinder). In addition to an increased expenditure on equipment by requiring special fittings, there is the further disadvantage that these cylinders do not reach the often required high acceleration values> 5 m / s ² . Thus, the Stf '! Motor is again loaded with the load torque and must additionally accelerate the piston of the working cylinder. Another disadvantage is that with such combinations different types of drive media are used. Object of the invention With the aim of the invention, the design of a vertically acting load balance, z. As in handling equipment and operating on the Cartesian principle gantry robots in the way that strongly energy consuming mechanical or hydraulic principles of load acceleration or load braking are replaced in favor of low-energy solutions, thereby avoiding an additional design load on robotics and significantly improve their functional properties.