The balancing machine factory developed a universal balancing machine for RZD trains

A leading Russian manufacturer in the field of development and delivery of balancing machines and vibration measuring equipment for enterprises in various industries, Scientific and Technical Center "Factory of Balancing Machines" in 2020 will complete the development of a universal balancing machine under the technical specification agreed with Russian Railways (project "RIF"). Pilot samples of the device will be tested in 2021.

Replacement of obsolete balancing machines

A modern train includes a large number of rotating mechanisms and units that excite vibration during train movement: main generators, traction motors, crankshafts and cardan shafts, fans, wheelsets, turbochargers, gearboxes, etc. Reducing vibration of these mechanisms and units increases the safety of train movement, increases service life and improves passenger comfort in the train.

The main way to reduce vibration of rotor mechanisms is qualitative balancing of rotors on machines, which is performed during repairs of rolling stock at locomotive repair plants (LRZ) and operational depots. Earlier LRZ and depots were equipped with balancing machines produced in Minsk, which have worked more than 40 years, became obsolete morally and physically and no longer meets the increased requirements for modern balancing equipment.

Now the "Balancing machines factory" carries out a mass replacement of out-of-date Minsk machines 9716, 9718 and 9719 by the machines BM-300R, BM-3000R and BM-8000R of resonance type, which are specially designed for balancing of rotors of the rolling-stock of RZD.

Basic units of the new machines are the objects of intellectual property and are patented by the "Balancing machines factory". High-quality antifriction bearings are used in the machines, which provide high service life of the moving elements and support rollers of the machine.

Most up-to-date technological solutions are used in the machines: hydraulic dampers for compensation of the limit radial displacement of the support legs in case of large initial unbalance of the rotor, pneumatic tensioning device for drive belt, pneumatic or hydraulic stackers for smooth placing of the rotors on the machine, roller guides for ensuring precise running of the machine support and axial movement of the roller equipment.

State-of-the-art solutions for balancing rotors on RZD rolling stock

The measuring-balancing unit (BCU) with highly sensitive vibration sensors provides high accuracy of measurements, good controllability, convenient operation of the operator during the balancing process.

BM-3000R machines are equipped with the special technological frame for balancing of anchors of traction motors. Universal design of the frame allows the balancing of all the range of traction motors on one frame.

Rotors of main generators are also balanced on balancing machines of model BM-8000P by means of special tooling - false shafts.

Diesel turbocharger compressors are balanced on BM-300R machines without the use of a tooling.

Wheel pairs of locomotives and railcars can be balanced on BM-3000P machines, but in connection with a great variety of wheel pairs designs, the presence on them of a large number of attachment units and parts in the form of gear wheels, bearings, brake discs, rotating reducers and the formation as a consequence of large initial unbalance, preference is given to the use of rigid type (pre-resonance) machines for their balancing, as evidenced by international practice. As a driving element for providing rotation of wheel pairs instead of the belt the cardan shaft is used, that is the optimum solution.

The peculiarity of balancing of compressor cooling fans and traction electric motors after their repair and restoration of parts and units is the necessity of their resonance tests. In this case the rotor rotation is carried out in the frequency range of 2100-2500 rpm, so the working area of the machine is enclosed by special protective screens which protect the operator from the accidental ejection of the part which has come off the rotor. Machines of this series have been supplied to the enterprises of the Russian Railways since 2020.

Specialized machines of rigid type are produced for balancing cardan shafts. Both two- and four-support driveshafts up to 4000 mm long can be balanced on these machines. The prototype of such a machine was manufactured and delivered to Russian Railways in 2019.

About the company

STC Balancing Machine Plant LLC is a leading Russian manufacturer in the field of design, development, delivery and implementation of balancing machines and vibration measuring equipment for enterprises in various industries.

The company provides the most complete range of products and services in this field: economic justification of implementation of the diagnostics and balancing systems, development of technical specifications, equipment installation, its adjustment, technical support, warranty repair, modernization, training of the operating personnel. At the same time, the plant performs modernization and service of both balancing machines of its own production and all balancing machines of third-party manufacturers.