Drive System

Sustainable and cost effective operation with minimal maintenance in wet and contaminated environments.

To achieve sound, sustainable and cost-effective rail operations

Driving systems for railway trains, such as gearboxes or traction motors, must have features that are powerful, sustainable, cost-effective and require low maintenance. These requirements are becoming more and more important because of the longer maintenance intervals and the increasing weight of rolling stock.

Traction motors must provide high speeds and withstand impact loads, and must also resist low load conditions, such as in coasting or cruise control mode. In addition, the sensitivity to discharge also makes traction motor bearings face unique design challenges.

Gearbox design requirements also put forward high requirements for gearbox bearings and bearing configuration. Specific challenges include a wider operating temperature range, high impact loads, and an increase in the overall load combined with the drive to reduce friction in the gearbox and reduce energy consumption.

We work with customers and operators to implement the latest requirements, innovate and deliver high quality products and services. We have rich experience in bearing design for railway drive systems. Our drive system bearings are designed to cope with highly polluted environments and operate in humid environments and under varying conditions such as speed, temperature, load, vibration and impact. In addition to developing new and innovative solutions, our extensive field experience provides a variety of commonly used bearings and bearing units, as well as drive system references, to make it easier to select the right product at the design stage.

Traction motor bearing unit

Bearing solutions that reduce maintenance requirements and extend maintenance intervals

Drive systems for railway applications such as gearboxes and traction motors must be robust, reliable, cost effective and have low maintenance requirements. This requires the use of special bearings and bearing units.

The SKF Traction motor bearing Unit (TMBU) is based on a compact and space-saving design that reduces maintenance requirements and extends service intervals. Thus, lower life cycle costs can be achieved.

The TMBU is a sealed pre-lubricated bearing unit designed for flange mounting on the motor housing. This unit uses a special grease, even at high temperature operation conditions also have a long lubricating life. The bearing unit is also equipped with non-contact labyrinth seals that do not wear out.

To reduce the risk of damage caused by current passing through the bearings, electrical insulation can be achieved using a hybrid design of INSOCOAT coating or ceramic rolling body. Overall, friction, friction heat and wear can be significantly reduced with the use of TMBU and properly installed machinery.

Electrically insulated coated INSOCOAT bearings

Prevent electric corrosion and improve the reliability of railway bearings

Harmful high frequency stray currents are inevitable in most applications in the railway industry. When the current passes through the rolling bearing, it will pose a threat to the reliability of the machine. Electrical erosion can damage and degrade bearings in traction motors, motors, and generators, resulting in costly downtime and unplanned maintenance.

Charged insulated coated INSOCOAT bearings are an extremely cost effective solution designed to provide high levels of reliability and uptime in electrical applications. The sealing protective coating on the outer ring or inner ring adds insulation properties to the bearing, thus protecting the bearing from the influence of harsh or even wet environment.

We used a precision plasma spraying process to coat the alumina insulation layer. There are two types of coating available: standard coating and premium coating. The standard layer provides a minimum resistance of 200 [mω], while the advanced layer provides a minimum resistance of 400 [mω].

INSOCOAT VL0241 and VL0246 are ideal for small and heavy traction motors:

Its design is based on cylindrical roller bearings and deep groove ball bearings.

The outer surface of the outer ring is electrically insulated by aluminum oxide coating

VL0241 standard layer 200 [mω]; VL0246 Advanced Layer 400 [Mω]

INSOCOAT VL2071 and VL2076 are perfect for larger traction motors:

Alumina coating is applied to the outer surface of the inner ring: holes, chamfers and end faces

Because the coating surface area is small, the capacitance is reduced

Improved electrical impedance

Compared with the coated outer ring design VL0241, the electrical insulation characteristics are improved

VL2071 standard layer 200 [mω]; VL2076 Advanced Layer 400 [Mω]