SPECHT

An innovative bistable solenoid.

RHEFOR has developed a new concept for bistable solenoids and applied for a patent. Compared to conventional solutions this new technology SPECHT exhibits:

  • up to 3x higher force at a given volume
  • shorter operating time
  • shorter delay time
  • lower power consumption due to high efficiency

Within certain dimensions SPECHT allows the avoidance of expensive rare earth magnets. If not a proportional but a pure switching function is required, SPECHT may in many cases replace pneumatic cylinders. Thus, by avoiding expensive compressed air, SPECHT can help lowering operating costs.

SPECHT is easily scalable. It can be build rotationally symmetric or in the form of cuboid from sheet metal packages.

The actuator is under continuous development and will be adapted to customer specific requirements.

The possibilities are demonstrated by the following FEM-simulation results.

  1. example-actuator ⌀=50 mm, l=59 mm with 3 mm stroke and >400 N force
    • Simulation assuming conventional materials (free machining steel) and direct 24 V supply with a coil resistance of 12 Ω.
      • stationary characteristics of the actuator:

        SVG-fig. of a stationary simulation of SPECHT
      • transient simulation of the actuator in the unloaded case (no external mass, no external restoring forces), energy loss per cycle 0.5 J (η=4.9%):

        SVG-fig. of a transient simulation of SPECHT
      • transient simulation of the actuator with a constant counter force of 200 N, energy loss per cycle 2 J (η=0.9%):

        SVG-fig. of a transient simulation of SPECHT
    • With soft magnetic composites and added electronics much improved timings and energy conversion efficiency are possible.
      • transient simulation of the actuator in the unloaded case, energy loss per cycle 0.02 J (η=97%):

        SVG-fig. of a transient simulation of SPECHT
      • transient simulation with a constant counter force of 200 N, energy loss per cycle 0.8 J (η=35%):

        SVG-fig. of a transient simulation of SPECHT
  2. example-actuator 35 mm x 35 mm x 71 mm with 6 mm stroke and ≈50 N force
    • stationary characteristics of the actuator:

      SVG-fig. of a stationary simulation of SPECHT

       A variation of the SPECHT-actuator allows for the optimization towards a particularly low velocity in the end position. Thereby a exceedingly low noise level and low material wear during operation can be achieved.
  3. example-actuator 92 mm x 92 mm x 174 mm from laminated sheets with 10 mm stroke and ≈3 kN force
    • stationary characteristics of the actuator:

      SVG-fig. of a stationary simulation of SPECHT
    • transient simulation with a load of 25 kg and energy losses of 4.4 J per cycle (η=71%); direct 100 V supply with a coil resistance of 5 Ω, the actual transient peak power is only 500 W:

      SVG-fig. of a transient simulation of SPECHT
  4. example-actuator ⌀=24 mm, l=16 mm with 500 µm stroke; monostable layout
    • stationary characteristics of the actuator:

      SVG-fig. of a stationary simulation of SPECHT
    • transient simulation of the unloaded actuator with direct 24 V supply and a coil resistance of 58 Ω; actual transient peak power 8.5 W; energy losses per cycle of 43 mJ (η=0.3%):

      SVG-fig. of a transient simulation of SPECHT
    • transient simulation of the unloaded actuator with 24 V-capacitor as power supply and a coil resistance of 2.6 Ω; actual transient peak power 60 W; energy losses per cycle of 29 mJ (η=41%):

      SVG-fig. of a transient simulation of SPECHT
  5. example-actuator 157 mm x 115 mm x 135 mm from laminated sheets
    • transient simulation with a load of 50 kg and energy losses of less than 70 J per cycle:

      SVG-fig. of a transient simulation of SPECHT
  6. example-actuator ⌀=26 mm, l=40 mm
    • transient simulation of the unloaded actuator with energy losses of less than 47 mJ per cycle

      SVG-fig. of a transient simulation of SPECHT