10.08.2026

Precision gearbox solution for radiation therapy patient positioning

When precision is critical, a standard gearbox is not always enough. For a patient positioning system used in radiation therapy, BJ-Gear was asked to develop a gearbox solution capable of meeting exceptionally high requirements for accuracy and performance. Based on an initial concept from the customer’s engineers, BJ-Gear carried out the engineering calculations and developed the final design of a compact, double-acting ball screw gearbox. The complete solution integrates the specially designed gearbox with a servomotor and holding brake. Following extensive static and dynamic testing, the gearmotor was approved for serial production. Today, BJ-Gear is responsible for manufacturing the components as well as assembly, testing and commissioning of the complete gearbox solution.

Benefits

High positioning accuracy

The specially developed gearbox provides the high level of precision required for accurate patient positioning during radiation therapy.

Compact custom design

A double-acting ball screw principle makes it possible to combine high performance and precision in a compact gearbox designed specifically for the application.

Complete tested solution

BJ-Gear handles component manufacturing, assembly and testing of the complete solution, including the gearbox, servomotor and holding brake, ensuring consistent performance for serial production.

Company profile

Elekta is a global medical technology company specialising in precision radiation therapy and cancer care. The company develops advanced systems and software that help clinicians deliver highly accurate and personalised cancer treatments.

Versa HD® is Elekta’s advanced linear accelerator platform for radiation therapy, designed to combine high treatment precision with efficient clinical workflows.

Problem Statement

The patient positioning system required a gearbox with exceptionally high levels of precision and performance.

The requirements were beyond what could be achieved with a standard or modified gearbox. At the same time, the solution had to be sufficiently compact to integrate into the patient table while providing the accurate and controlled movement required for patient positioning during radiation therapy.

A gearbox therefore had to be developed specifically for the application.

Solution

Working from the initial concept developed by the customer’s engineers, BJ-Gear performed the necessary calculations and engineering work to determine the final gearbox design.

The resulting solution is based on a double-acting ball screw gearbox, providing the required precision and performance within a compact design.

The gearbox was integrated with a servomotor and holding brake and subjected to extensive static and dynamic testing before being released for serial production.

BJ-Gear subsequently took responsibility for manufacturing the gearbox components as well as assembly, testing and commissioning of the complete gearbox solution.

Elekta — solution
Technical drawing 1