SKF Explorer sealed spherical roller bearings enable new generation of gearless, direct drive elevators

The challenge

Switching from a geared motor to a direct drive, gearless elevator design, China’s Shanghai Mitsubishi Elevators faced a serious design challenge. With no gearbox and no gear oil, the open bearings supporting the rotating shaft would have to be regularly lubricated – a difficult and costly regimen that could potentially jeopardize brake function due to grease leakage.

The solution

SKF consultants recommended SKF Explorer sealed spherical roller bearings. Designed to accommodate very heavy radial and heavy axial loads in applications where misalignment or shaft deflection can occur, these virtually maintenance-free bearings can have a service life as long as that of the drive system itself, 20 years or more, depending on operating conditions.

Made of an extremely clean, reduced-oxygen level steel that provides greater strength, SKF Explorer spherical roller bearings even exceeded the customer’s requirements for heavy loads, low noise, effective lubrication, and protection against solid contaminants and moisture.

The results

After 3 months of endurance and function testing, the manufacturer was so impressed by the performance of the sealed spherical roller bearing that they switched their entire production to this type of bearing and entered into deeper development talks with SKF.

As a consequence, SKF and Shanghai Mitsubishi are partnering on the shaft system and bearing requirements for the development of the company’s newest elevator design. With a descending speed of 6 metres per second, it will be the fastest elevator in China.
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