Electric Actuator: Characteristics of Rack and Pinion Motor (L Series)

The following are the 3 important characteristics of rack and pinion motors.

  • Rack Speed
  • Maximum Transportable Mass
  • Holding Force

Rack Speed

The rack speed can be calculated by the following formula, depending on the pulse speed from the controller.

\(\begin{align}V= f\ \cdot\ \Delta \ell\end{align}\)
Δℓ
Resolution [mm/pulse]
V
Rack travel speed [mm/s]
f
Pulse speed [Hz]

Maximum Transportable Mass

Refer to the product characteristics table.
The maximum transportable mass in the characteristics table is the value when the rack is moved horizontally. If the rack is moved vertically, subtract the rack mass (refer to the dimensions) or the force equivalent to the rack mass (rack mass × 9.807) from the value in the characteristics table.

Holding Force

Refer to the product characteristics table.

Rack Play (Initial value)

The rack is supported by rack bushings in 2 places on the rack case. Since there is a slight gap between the rack bushing and the rack to allow sliding inside the rack bushing, the rack moves in the direction shown in the figure.

A, B Direction 2 mm max.
C Direction (backlash) 0.5 mm max.
D Direction 0.5˚ max.
LAS Series
  • Play in the A and B directions is measured at 500 mm from the end face of the case.
  • Play in the rack will increase with continued use over time. For applications where play may be a problem, please provide an external guide.

Technical Reference