Nippon Pulse’s Linear Shaft Motor (LSM) is a brushless, high-precision direct drive linear servo motor with a tubular design. The motor consists of a magnetic shaft and coil assembly (forcer), and is driven and controlled by the flow of current. The Linear Shaft Motor can replace ball-screws, pneumatics, U-shaped motors and other linear motion systems.
NPM’s LSM series produces high precision, high payload linear servo motors used by creators of advanced machines across the high tech landscape. Nippon Pulse’s Linear Shaft Motor is a brushless, high-precision direct drive linear servo motor with a tubular design. The motor consists of a magnetic shaft and coil assembly (forcer), and is driven and controlled by the flow of current.
NPM’s simple, high-efficiency, high-precision Linear Shaft Motor is unique in that it requires no maintenance over its lifetime. The servo motor consists of only two parts: a magnetic shaft, and a “forcer” of wound coils. The Linear Shaft Motor offers ultra-high precision because it has no iron in the forcer or shaft, giving you the precision and zero cogging expected in a coreless design while providing the stiffness expected in an iron-core motor. Because the forcer coil completely wraps around the shaft’s internal magnets, all the motor’s magnetic flux is efficiently used. This allows for a 0.5mm to 2.5mm nominal annular air gap between the shaft and forcer. This air gap is non-critical, meaning there is no variation in force as the gap changes over the stroke length of the device.
Design Concepts of the Linear Shaft Motor
- Simple: Two parts and a non-critical air gap
- Non-Contact: No wearing and maintenance free
- High Precision: Ironless design so all the magnetic flux is used efficiently
Linear Shaft Motor Specification Overview
- Variety of shaft diameters, ranging from 4mm to 100mm
- Stroke lengths of 20mm to 4.6M
- Achievable peak force of 2340N
- Maximum continuous force of 585N
In addition to linear servo motors, Nippon Pulse also offers two types of linear stages – Acculine SLP stages and Nano-positioning SCR stages – both of which are high-precision, single-axis linear stages. Both include an integrated Linear Shaft Motor and encoder (though the encoder resolution is different between the two series). Due to their compact size, both are ideal for small-scale applications or applications with space limitations. Most importantly, both types of NPM stages provide the speed and performance expected of servo stages.
When designing any linear motion system, one of the main considerations in selecting a stage series will be the level of precision required for the application. The main difference between NPM’s two linear stage platforms is position accuracy. For the absolute maximum resolution, the SCR stage series has performance specifications that compare strongly to any platform in the industry. For high precision motion, but more comparable to ballscrew-type position accuracy, the SLP stage series is frequently the better choice.
NPM’s SCR stages include an optical linear encoder to enable sub-nanometer resolution, along with an integrated cross-roller guide and motor cables. This stage series produces extremely accurate results with no loss in stability.
NPM’s SLP stages include a 1-micron resolution encoder, along with integrated bearings and a linear guide. The SLP series is perfect for simplifying the transition from ball-screw systems, and provides an unmatched force-to-volume ratio. In addition, the dramatic improvement in maintenance costs compared to ballscrew-based motion platforms makes the SLP series a contender for most system designs.
