motcom® BeCOMS® / BCom
Bearing Condition monitoring


The BeCOMS / BCom system can be used on engines and machines (turbines, pumps, etc.) where the shaft is not electrically isolated from bearing shells. It utilises the thermo-electrical (Seebeck) effect for monitoring the condition of the engine / machine, bearings and slip surfaces, allowing to recognise failures at an early point, which prevents large-scale part damages. For other machines than piston engines, a version of the system named BeCOMS® EM is available

On diesel engines, the BCom system measures and evaluates thermal voltage between the crankshaft and bearing shells, signalling changes that can be interpreted as dangerous.

Damages to bearings can be caused by metal particles within the bearing clearance, low oil pressure, overheated oil, etc. The result of such malfunctions is a breaking oil film between the sliding parts.

As soon as the oil film is broken a thermo voltage occurs due to the friction between the different metallic alloys.

Functional description

The BCom system is an online condition monitoring system which measures and analyzes the thermo voltage. The main parts of the system are the Slip Ring Encoder, the Evaluator and the specially designed Data_Log software.

One Slip Ring Encoder (SRE) is installed on the cover of the free end of the crankshaft. The rotating shaft of the SRE is mechanically attached to the free end of the crankshaft, usually with a vibration damper.

One BCom Evaluator is installed as the Local Control Panel where the measured values are displayed and the signal evaluation is performed. These values can also be displayed on a computer in the engine control room via RS485 communication cable with the help of BCom Data_Logger software which provides online visualization and storage of the signals transmitted by the Evaluator. Furthermore, stored measurement data can be viewed and analysed by Data_Indicator software and motcom loganalyser software.

Slip Ring Encoder (SRE)

The Slip Ring Encoder (SRE) contains a special slip ring with redundant carbon brushes which receives the thermo voltage signal from the crankshaft-engine system. The SRE is also equipped with an incremental encoder to bring the measured signal in relation to the rotation of the crankshaft.

See a picture sequence of installation step by step

The Evaluator is designed to withstand the environment in the engine room. Its vibration resistance allows an installation near the engine without any special support. For installation on the engine, a special vibration damping feature is available.

The Evaluator consists of a alloy case, a liquid crystal display (LCD), three LEDs indicating the system status and five membrane buttons for user interaction. A powerful micro controler inside the Evaluator analyzes the measured data continously, displays the data on the LCD and triggers the alarm relais in case of thermo voltage. The bargraph display makes recognizing the current measurement data easy.

Data_Log Software

The Data_Log software is capable of receiving measurement data of up to six connected BCom systems simultaneously. It is used to display and store the data for later analyzation.

The Data_Log software also supports the localization of the damage inside your engine. This is done by additionally using the cylinder firing sequence of the engine and the incremental encoder of the SRE. The result of all these information is the “Polar Diagram” of the Data_Log software. It shows the measured thermo voltage over the engine rotation. The diagram also contains the firing sequence of the engine so the operator is able to recognize easily which bearing is affected.

click to see BeCOMS / BCom functionality as video animation
BeCOMS® / BCom Advantages

- Easy installation
- Online and continuous monitoring
- Optimization of the availabilty and reliabilty of the engine
- Early and reliable detection of bearing anomalies
- No unnecessary bearing inspections
- Minimizing engine maintenance and service costs
- Maintenance free

Currently available certificates for BeCOMS® / BCom system:
Click here to see a BeCOMS / BCom demonstration video with the demo model