More Than Just a Gearmotor Expert

Bodine offers improved safety for caregiver and patient in assisted mobility markets

To cater to all the baby boomers who are now becoming seniors, mobility-enhancing products have expanded in demand. Products One of the most significant devices for achieving interior access and egress is motorized stairlifts. In such systems, reliability is key — all the parts have to work consistently, even if there’s a power failure.

The Problem: Industry Safety Compliance

When an original equipment manufacturer of chair lifts had problems meeting demanding industry safety requirements, they turned to Bodine Electric Company. Namely, the stairlift had to satisfy regulations relating to stopping time in case of power failure.

The original design used a Bodine right-angled RPM gearmotor with self lock worm gearing and fail-safe braking. In principle, these features should have kept the stairlift in position and slowed it to a gentle stop when power failed. However during trials, it did not comply with the stopping requirements.

Understanding the Application Issues

Bodine engineers soon figured out two major problems when it came to performance:

Self-locking gearing limitations

Worm gearing is excellent for holding a load when the motor stops, but poor for dynamic braking. It is ineffective to entirely offset the inertial momentum torque of the motor armature.

Improper brake wiring

The safety brake had been connected in series with the motor. The manufacturer wanted the brake to go on immediately when power was removed. But because of the DC motor physics, it continued to be a generator until it finally halted rotating. The brake would only then apply, the stairlift not stopping within an acceptable timeframe.

Bodine’s Engineering Solution

To solve these problems, Bodine engineers suggested separating the power connections for the motor and brake. By decoupling the two systems, there could be no delay for power-off brake to set from any remaining motor rotation.

For the parameters of design changes, after these modifications are met, the OEM can achieve compliance to industry braking performance standards. The remanufactured units did not just stop the lifts safely and gently – it also helped regain trust in the stairlift’s reliability.

Benefits of Bodine’s Stairlift Motor and Brake Design

• Better compliance with industry stopping time standards for safety
• Independent braking provides instant stopping power
• Wormgearing in right-angle gearmotor ensures secure load holding
• Brake design provides fail-safe reliability in case of power loss
• Proven engineering expertise from Bodine to help solve custom application problems

Durable Gearmotors Ideal for Assisted Mobility

This application is not only another example of Bodine more than just a gearmotor supplier, we also provide the engineering power so that our OEM customers can built systems according to the highest safety and performance requirements. For stair lifts and patient lifts to myriad other assistive mobility devices, Bodine custom gearmotor and brake solutions give you confidence where safety is paramount.