SK2122011U1 - Actuator with artificial muscles - IV. - Google Patents

Abstract

Actuator with artificial muscles - IV. It consists of a base plate (1) firmly attached to the two pillars (2), which are firmly attached bearing housings (11). Through them is inserted shaft (3) firmly attached to the cam roller (4), after which it is passing through the flexible belt (5), whose ends are connected with artificial muscles (6) and these are attached to opposite ends of the rear bracket (7). At the same time the shaft (3) attached firmly round the arm (12), which is connected to the arm (8) and is associated with loading (9).

Description

The technical solution concerns the actuator with artificial muscles - IV. Artificial muscle actuator is an automation and robotics device where light, powerful and movable drives are usually used.

BACKGROUND OF THE INVENTION

Current rotary motion generating devices using artificial muscles are designed as mechanical systems with two rigidly anchored artificial muscles that are connected by opposite ends with a flexible bending band. This belt is threaded onto the circumference of the rotary roller which is slid onto the actuator shaft and is mounted in bearings. These are located at the ends of the actuator support posts. The actuator thus constitutes an assembly where the columns are mounted on the support plate and at their ends there are bearings, a shaft and a load arm, with the artificial muscles positioned along the columns. Such an actuator forms a relatively long and slender unit with satisfactory weight and size characteristics. In the case of the application of pneumatic artificial muscles, this device significantly exhibits a non-linear relationship between the varying air pressure entering the artificial muscles and the angle of rotation of the arm attached to the (output) shaft of the actuator. This characteristic has a shape similar to a logarithmic curve, the nature of such a non-linearity (type of saturation) causes a decrease in the actuator torque at larger position values (rotation). This phenomenon is caused by the properties of the artificial muscles used, mainly because the constructors of the actuators are trying to utilize the extent of contraction (contraction) of the artificial muscles to the full. This also fully manifests the non-linear properties of artificial muscles, which are very pronounced in these circumstances. The drive with such an actuator has insufficient and asymmetric stiffness at larger turns. Accurate position control of such a system is complicated and its capabilities are limited.

The essence of the technical solution

The above-mentioned drawbacks are eliminated by the proposed technical solution, which is based on the concept of generating a constant (or to a small extent varying) torque on the actuator shaft by applying an axially symmetrical eccentric (pulley with a shifted center of rotation outside the pulley center) hitherto used circular-shaped pulleys with a center of rotation identical to the geometric center.

The actuator in the previous solution works that way. that the initial position of the arm is adjusted by filling both artificial muscles to a certain (maximum) pressure of the gaseous medium (air). Muscles, due to the same contraction, define the position of the actuator arm to the reference (initial) position (parallel to the longitudinal axis of the actuator). By discharging the gas from one artificial muscle, it is prolonged and at the same time the other artificial muscle contractions, which is still under initial pressure. This action causes the bending of the flexible belt and at the same time the roll of the pulley accompanied by the rotation of the shaft. Each rotation of the shaft (caused by the loss of a certain volume of air from the respective artificial muscle) is given by the torque equality between the artificial muscles. As the torque decreases from both artificial muscles with increasing rotation, the stiffness of the actuator in both directions decreases as well. This is a consequence of a non-linear decrease in the strength of artificial muscles depending on their contraction. Due to the constant radius of the pulley, the torque characteristic of the actuator is also non-linear (depending on the angle of rotation of the shaft). Remove, respectively. suppression of this phenomenon is possible when, instead of a constant-radius roller rotating around its geometric center, we apply a constant-radius roller rotating around a point lying outside its geometric center (on the longitudinal axis of the actuator) with a radius of rotation increasing as the shaft rotates, t. j. an eccentric roller. In this way, it is possible to achieve a smaller decrease in the torque on the actuator shaft relative to the prior art solution and thus a greater and symmetrical stiffness of the actuator. The proposed technical solution envisages the use of an eccentric roller with any surface, i. j. toothed for chain or toothed belt drives, eventually smooth for flat, V-belts, for cable ducts and the like.

BRIEF DESCRIPTION OF THE DRAWINGS

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows the overall arrangement of the functional parts of the device in front view, and FIG. 2 shows the overall arrangement of the functional parts of the device in a side view.

EXAMPLES

In FIG. 1 and FIG. 2 shows an embodiment of the invention. It shows the overall arrangement of the functional parts of the device. Actuator with artificial muscles - IV. it consists of a base plate 1 with two columns 2 fixedly connected to which the bearing bushes 11 are fixedly connected. A shaft 3 is fixedly connected to the eccentric pulley 4 by means of which the flexible belt 5, whose ends are connected to artificial muscles 6 and these are secured to the rear brackets 7 at the opposite end.

Industrial usability

The device according to the proposed solution can be used in short and long term application of functional units in which pneumatic or other artificial muscles are used in individual, antagonistic or other connection. The system of the device can also be used on other actuators (electric, hydraulic), their dimensions and performance depend on the size of the equipment used. The device can be used individually, but can be mechanically interconnected into more complex units (eg in robotics).

Claims (1)

PROTECTION REQUIREMENTS Artificial muscle actuator, characterized in that it consists of a base plate (1) with two columns (2) fixedly connected to which the bearing bushes (11) are fixedly connected, through which the inserted shaft (3) is fixedly connected to the eccentric roller (4), after which the flexible band (5) is threaded, the ends of which are connected to the artificial muscles (6) and these are attached to the rear supports (7) by opposite ends and at the same time the arm hub (12) is fixed ) which is connected to the arm (8) and this is associated with the load (9).