Linear actuators
The universally usable linear drives from Nanotec offer a multiplicity of new, low-priced and powerful possible applications.
- Simple and flexible motor construction considerably reduces the system costs
- Stroke-independent movement to any position
- Highly reproducible resolutions (<1?m) and fast feeds (>1000 mm/sec.) for the same construction volume achieve uniform construction platforms
- Direct force coupling to the load requires no additional components, thus offering rigid and light mechanics
- Static spindles enable highly dynamic and rigid machine constructions as well as multimotor operation
- Due to low energy requirements, even high forces can be delicately regulated
- Partly self-locking so no additional brake is necessary
- Stroke is only dependent on the available spindle length
- Replacement for hydraulic and pneumatic cylinders with considerably higher flexibility
| Series | Size (mm) | Thrust, max. (N) | Resolution (mm/Step) |
|---|---|---|---|
| PM stepper motor linear actuators | 25-55 | 25-100 | 0.025-0.0417 |
| Linear actuators with fine-pitch screw threads | 28-56 | 40-100 | 0.001-0.005 |
| Linear actuators with trapezoidal spindle | 28-56 | 15-1000 | 0.01-0.05 |
| Linear actuators with ball screw | 28-56 | 350-1800 | 0.005-0.01 |
| PM stepper motor linear positioning drives | 8-35 | 3-40 | 0.008-0.01 |
| Linear positioning drives (standard) | 20-42 | 15-300 | 0.0005-0.005 |
Further important information on the use of linear actuators
The achievable resolution, precision feed control speeds and forces are calculated on the basis of the pitch of screw (p in mm), propelling torque flow characteristics (Md in Ncm) and efficiency as follows:
- Resolution in mm/step =/(360°/step angle) e.g. 1 mm/(360°/0.9°) = 0.0025 mm/step
- Feed rate = f • resolution e.g. 2000 1/s • 0.0025 mm = 5 mm/sec
- Thrust in N = MdMot • 2? • efficiency/p e.g. L5609X approx. 15 Ncm at 2 kHz = 15 • 6.28 • 0.1/0.1 cm = 94 N (peak torque)
- Efficiency = According to DIN 267 - Sheet 1; the efficiency is: fine-pitch screw thread approx. 0; trapezoidal spindle approx. 0.4 ; ball screw spindle approx. 0.9. In addition, the static and rolling friction (0.9 to 0.7), the surface structure (roughness/hardness of the spindle and nut), material pairing (steel/steel), (steel/copper bronze), (steel/POM plastic), pollution severity and concentric spindle guide must be taken into account in the calculation of the service life estimate. It is imperative to determine the operational stability and possible service life in a real trial. (An empirical efficiency for the overall system of approx. 0.3 results for the trapezoidal spindle and approx. 0.7 for the ball screw)
The force and power ratings specified in the datasheets are based on a power-up time of approx. 10% - 20% and must be reduced accordingly for higher values.
The axial play in the direction of the motor is approx. 0.1 to 0.7 mm for 20N.
With various procedures for surface treatment (e.g. from Balzers, Mifa, Ikos) in the meantime coefficients of friction can be greatly reduced and the resistance to abrasion considerably improved.
Normally the spindles are wedged or fixed into the moving part.
For all other applications in which this fixing is not possible or a free spindle end must move the load, appropriate antirotational devices are offered by Nanotec and delivered in part already mounted on the motor. (The traveled distance must then be specified.)
Linear adjusting mechanisms and movements are a frequent task definition for many constructors. For quite some time the linear actuator and stepper motor family L.... has been successfully deployed in numerous applications (such as control, dosing, leveling, stroke, positioning, adjustment and closing tasks, path independent pressure and tractive force adjustment and many more) due to their versatility as related to force and positioning speeds.
