Right Angle Gear Motor for Residential Elevator Door

Overview

We were approached by a residential hydraulic elevator manufacturer that was feeling the effects of supply chain disruptions from an incumbent motor supplier. The motor’s function was to open and close the doors to the residential elevator cab. Our customer could no longer tolerate the inconsistent lead-times and late deliveries, as most of their projects are planned months in advance and require custom fabrication.

Like any growing industry, residential elevator and automated door manufacturers rely heavily on their supply chain. For any OEM, a disruption in the supply chain can have top-to-bottom impacts on their ability to operate and get finished goods delivered to customers.

To further complicate matters, the right angle gear motor the customer had been using was a completely unique design by the prevision manufacturer. Since this specific right angle motor design was proprietary to that manufacturer, it was impossible for our customer to source a drop-in replacement. This customer decided to reach out to ISL Products, for our expertise in dc motors and gear motors as well as our dedicated engineering and design support.

Challenge

We were faced with two major challenges with this project, time and space.

Time was of the essence; our customer had a limited supply on hand and new orders were coming in. The incumbent gear motor supplier had production lead times of more than 6 months. In addition to the long lead times, many times the supplier was late on the agreed upon deliveries, furthermore, causing additional stress and interruptions.

The other challenge for ISL Products was to design a right angle gear motor that met the customers’ required performance while fitting into their confined space. This meant that the gearmotor had to have a high peak efficiency. The incumbent gear motor had a unique design, and the clients’ other components and systems had been designed around this unique motor. The previous design was a large permanent magnet motor with integrated worm gears, which provided the right angle output.

Since the client knew that they were going to need to redesign some mating components and housings, they challenged us with downsizing the overall gear motor package to optimize space in their elevator door mechanism. The gear motor had to fit within a narrow channel, and the mechanism that the motor was actuating was perpendicular to the DC motor body, preventing them from using an inline gear motor.

Solution

For the geared motor design, we knew one of our ⌀ 42mm brushed planetary gear motors with a 24:1 reduction gear ratio would provide adequate starting torque, while being slim enough to fit within the narrow channel. The gearbox is equipped with a ball bearing to help accommodate loads and output torque. We then added an additional bevel gearbox to the output shaft of the planetary gearbox to provide the 90° output. Our right angle gearbox consists of two bevel gears with a 1:1 ratio, therefore not affecting the overall gear motor performance.

Our straight-forward approach allowed us to meet the dimensional and on load performance requirements for this application without significant impacts to manufacturability. We made a custom output shaft to mate with preexisting gearing in their assembly, to reduce the number components that needed to be changed. Additionally, to streamline the installation process for the customer we assembled the gear motors with lead wires, stripped and tinned. We were able to turn around these samples in just under 3 weeks.

In the effort to mitigate the effects of lengthy lead-times, ISL Products provides logistics and supply chain services through a million square foot storage facility. This is free of charge to all customers. Our initial lead time for this item, including freight transit, is around 14 – 16 weeks. This reduced the customer’s lead time by more than 30%.  We manufacture the entire blanket order and release them on a quarterly basis, per the customer’s schedule. Our lead times only affect the initial release. Since we manufacture the complete lot together, all remaining releases are in stock and ready to ship out at a moment’s notice from our conveniently located warehouse in Missouri.