Visit the Procter Machinery Guarding web site

Speed detection at half the price of alternatives

A Rowe Hankins Components product story

Edited by the Engineeringtalk editorial team May 14, 2004

A new range of speed detection devices is available from Rowe Hankins Components.

A new range of speed detection devices is available from Rowe Hankins Components.

Half the cost of optical speed detection technology, the new equipment is easier to install and more reliable.

In addition, it can be integrated into on-train management and recording systems.

Why use speed detection devices? By monitoring speed accurately at each powered axle, it is possible to synchronise speed from each wheel set to ensure smooth and balanced power delivery.

This gives rapid acceleration and braking without wheel spin or slide.

Positive benefits include avoiding excessive power use, damage to wheel sets or track and a reduction in downtime for service attention.

All Rowe Hankins speed monitoring systems use magnetic disturbance - the Hall-effect - to generate a pulse that is directly proportional to speed.

This produces a strong signal that cannot be degraded by EMC, RFI and other forms of interference.

The company offers both Hall-effect speed probes and pulse generators.

Speed probes are often installed as a retrofit directly to the gearbox, using the teeth on a gearwheel as the target to create the pulsed signal.

These probes cope well with this environment, the magnetic pulse being unaffected by oil, grease or other contaminants.

Service experience with this equipment confirms their extreme reliability with in excess of 10million hours mean time between failures.

However, engineering problems may prevent this solution in some cases.

For these situations, Rowe Hankins have an alternative, its pulse generator.

The Rowe Hankins pulse generator eliminates the engineering difficulties that can occur when retrofitting probes into gearboxes.

They use a precision-engineered target that is fitted, like a top hat, over the end of the powered axle or on the motor shaft.

This target is easy to install and requires no special tools.

It provides a highly reliable and accurate signal that is detected by a Hall-effect sensor that can be located up to 10mm away.

Unlike optical pulse generators, this device is unaffected by contamination, motion or vibration and has a wide band of tolerance to misalignment.

The pulse detector can detect both forward and backwards motion, and therefore provides the signalling for rollback protection.

The target also has the capacity for other sensors to be fitted to monitor functions such as vibration and temperature.

Data from these sensors is vital input for on-train monitoring and recording systems that give early warning of potential problems.

This allows timely action to prevent costly long-term damage or component failure.

Rowe Hankins speed monitoring products are winning friends around the world; metro systems in Shanghai, New York, Washington and Sacramento use them.

They can also be found on French freight locos and on stock in Brazil, Australia and in the UK on the London Underground.

The company has an active research and development department that works with train builders, operators and leasing companies to provide practical solutions to improve safety, maximise uptime and extend service life.