Linear actuator with energy storage

Abstract

Linear actuator with energy storage, which enables movements to be transmitted quickly and precisely, without motion errors and with high dynamics.

Description

[0001] Linear actuators are used in motion platforms in the automotive industry for new developments and in the entertainment gaming industry for sim racing, commonly known as “motion simulators”.

[0002] This “actuator with energy storage” is a technical development that is new and unique on the market.

[0003] To simulate vehicle movements as realistically as possible in a simulator, it is necessary to use good software. Today's state-of-the-art technology allows for the recording of race tracks with millimeter precision using laser scanners. This allows even the smallest changes in the race track to be represented in the simulation, provided the simulator allows it.

[0004] Four actuators on a 3-DOF (Degree of Freedom) cockpit enable up and down, roll, and pitch movements. The simulation software sends a motion command to the actuator's control unit, which then transmits the command to the actuator (servo motor) as a motion signal. The motion signal (step, direction) consists of two pulses: step (encoder pulse) and direction (+ / -). How quickly an actuator reacts (extends and retracts) also depends on the amount of mass being moved.

[0005] During fast actuator movements with constant changes in direction under high load, it can quickly happen that movement signals are not fully executed, resulting in movement errors.

[0006] With my “linear actuator with energy storage” there are hardly any, if any, movement errors because it can implement movement signals faster and more precisely.

[0007] A "state-of-the-art" search yielded no results using a wide variety of search criteria. For example, "actuator with energy storage," "actuator with auxiliary springs," "actuator with kinetic energy recovery," "actuator with tension spring support," and other combinations.

[0008] One problem with linear actuators for driving simulations is that they are required to move large amounts of mass very quickly and precisely. The forces to be overcome are inertial forces. Inertial forces, also called mass inertia forces, always act in the opposite direction to acceleration. They occur as actual forces in accelerating reference systems such as the Earth. In my invention, the mass to be moved is supported by tension springs.

[0009] In the resting position, without load, the tension springs are relaxed, and the push-pull shaft is fully extended. The vertical load (the mass of the cockpit and the user) stretches the tension springs, and the shaft is retracted until equilibrium is achieved. The tension springs are designed so that the forces balance approximately at the actuator's center stroke position. This can be adjusted by slightly preloading the springs. Furthermore, the measurable motor load can be used to determine the optimal, load-neutral extension length, which can then be set on the motor controller as the starting position (standby position) for the simulation.

[0010] In a typical actuator movement, the cockpit descends, and the movement is supported by the mass of the cockpit and the user. The tension springs expand further, storing the energy, which then reduces the inertial forces during the next upward movement and supports the actuator motor acceleration. This results in the actuator motor responding much faster to changes in direction, thus transmitting more detail about the travel path. One can also assume a higher motion resolution of the actuator.

[0011] In addition, measurably faster and more precise movement dynamics can be achieved with lower motor power.

[0012] The problem underlying the invention is, as stated, to create an actuator that enables movements to be transmitted quickly and precisely, without movement errors and with high dynamics.

[0013] The problem is solved by the feature in claim 1 of the invention: To reduce the energy required by an actuator to move a mass (lift), tension springs are arranged around the push-pull shaft. The attachment to the base plate and the sliding slide of the revolving nut ensures the extension of the tension springs when the push-pull shaft retracts. In the rest position, the force of the tension springs is equal to the mass to be moved; a (rough) equilibrium exists, and the motor load is at its lowest. Up and down movements from this starting position can be performed much faster and more precisely by a servo motor.

[0014] An advantageous property is achieved by the feature in claim 2 of the invention: To ensure accurate and precise tension spring arrangement, receiving openings are placed in the base plate, and on the sliding slide of the rotating nut there is a receiving cross with a fine adjustment of the tension spring.

[0015] An advantageous property is achieved by the feature in claim 3 of the invention: The servomotor's thermal energy is conducted through the motor shaft into the coupling. To prevent the coupling from loosening due to thermal expansion and to also dissipate the motor heat, fan impellers are integrated into the motor mount. The required rotary motion is dissipated by a slip clutch on the motor shaft and transmitted via a bevel gear to the fan impellers, which are mounted on their outer edges.

[0016] Because the engine heat is dissipated in this way, the available engine power under load is also increased. In summary, the advantage of this invention is: “Linear actuator with energy storage”

[0017] The integration of the tension springs enables an actuator with energy storage that can transmit movements under relatively high loads much faster and more precisely and requires less energy than actuators of the same size without energy storage.

[0018] The following features are evident from the drawing and the further explanations. Drawing #1 shows:

[0019] A side view and a cross-sectional view of the “linear actuator with energy storage”.

[0020] The servomotor (1) on the motor mount (3) with the bevel gear (2) and the fan wheels (4) for heat control of the servomotor and the coupling (5). The threaded spindle (9) with recirculating nut required for linear movement in the slide valve with a mounted crosshead (6) for attaching the tension springs (7). The push / pull shaft (8), screwed into the slide valve and the spherical bearing (11), for fixing to a mounting frame. The base plate (10) for accommodating the tension springs and the linear end bearing (12) for guiding the push / pull shaft. List of designations 1 servo motor 2 bevel gear 3 Engine mount 4 fan wheels 5 Clutch 6 Mounting cross 7 tension springs 8 push-pull shaft 9 threaded spindle 10 Base plate 11 spherical bearings 12 Linear repository

Claims

[1] Linear actuator with energy storage that allows movements to be transmitted quickly and precisely, without movement errors and with high dynamics. [2] characterized by that tension springs create an energy storage device that reduces the mass inertia forces and thus supports acceleration. [3] characterized by that the tension springs are precisely mounted in the base plate at the lower end and on a cross-shaped support with fine adjustment at the upper end. [4] characterized by that fan wheels for cooling the motor and the clutch are integrated into the motor mount and are moved via a slip clutch on the motor shaft.

Images