Hydraulic Traction Drive Systems Modernize Railway Vehicles
Since 1977, Chvalis, a premier distributor of Parker Hannifin based in the Czech Republic, has been focusing on the development and construction of hydraulic systems for the needs of general industry and mechanical engineering, working toward modernizing the Czech Republic. One specialty of the company is providing technical solutions and delivery of hydraulics for railway vehicles such as diesel locomotives and railcars. This includes not only new hydraulic systems but also modernization and reconstruction of obsolete vehicles.

About Chvalis

Chvalis is an expert on delivering turnkey solutions according to rail manufacturer’s specifications, including delivery, installation and commissioning. Chvalis has been using Parker’s products since 1992 in its systems for their unmatched quality, reliability and security. Components also meet the most demanding certifications. In the railway industry, Chvalis is the holder of the Certification of Technical Competence of the Czech Railways supplier and the SŽDC Supplier’s Certificate.

Thanks to its extensive network of local branches, which are always associated with the ParkerStore service and ParkerStore sales hydraulics and tires, Chvalis is able to provide rolling stock operators 24-hour warranty and post-warranty service. The ParkerStore retail locations are fully equipped for the production of hydraulic hoses and are certified by the “ParkerStore Hose Certification Workshop.” 

Exceptional order for CZ LOKO

Until 2013, Chvalis supplied hydraulic systems only for auxiliary drives, such as compressor drives for compressed air production; the drive for the combustion engine cooling fans and the electric alternator drive for the production of electric motors. In 2013, the company received a call for a comprehensive design and solution for the supply of a complete hydraulic traction drive, including auxiliary drives for 35 units of MUV series 74.02 001-035 series, for CZ LOKO, the manufacturer and supplier of Czech Railways – SŽDC. 

Innovative open hydraulic system

Chvalis has developed a technical solution for its own drive – an unconventional way of using its own innovative, open-circuit hydraulic system instead of competing with a preferred closed circuit. The system, while technically more demanding, precisely and comfortably addresses all the requirements of all traction control conditions controlled by the parent electronic control system of the vehicle. In addition, the circuit allows for hydraulic braking, which was used for the cruise control system. This makes the work of the drivers more efficient and saves the cost of the vehicle operators, reducing the wear of the brake discs of the standard pneumatic braking system of the vehicle. The standard brake is used most of the operating time, using this circuit for braking, until the vehicle stops. 

Hydraulic circuits are built using the Parker product portfolio, including Ermeto E02 pipe systems and hose systems from certified hoses for rolling stock. These hydraulic circuits, mainly PV-plus piston control pumps in conjunction with the  F11, F12, F1, F2, and F14 hydraulic motors of the V14 series, deliver a minimum fault, provide high reliability and long service life.

Thanks to previous experience with the 35-piece MUV74.02 series, Chvalis was asked by CZ LOKO’s customer for the design and delivery of a complete hydraulic traction drive and auxiliary drives for a new series of 50 MUV 75.00 Universal Motor Vehicles. This new unit had the requirement to maintain the same hydraulic traction drive that has proven itself in the past series. In addition, the requirement to increase the hydraulic proportional brake power and increase the number of auxiliary hydraulic circuits has been accepted: hydraulic hand, grass mower, hydraulically independent trolley tipping system, and suspension lock. 

After the demanding testing of the first prototype in December 2017, the production of a 50-piece series of cars was launched in January 2018, again using the innovative Chvalis hydraulic system with proven hydraulic components from Parker.

Headed to InnoTrans?

InnoTrans is the leading international trade fair for transport technology and takes places every two years in Berlin, Germany. Sub-divided into the five trade fair segments Railway Technology, Railway Infrastructure, Public Transport, Interiors, and Tunnel Construction, InnoTrans occupies all 41 halls available at Berlin Exhibition Grounds. The InnoTrans Convention, the event’s top-level supporting programme, complements the trade fair.

A unique feature of InnoTrans is it’s outdoor and track display area, where everything from tank wagons to high-speed trains is displayed on 3,500 metres of track. Visit Parker at Booth 206, Hall 10 or learn about our innovations to keep you on track on our solutions page.

Related Articles:

What Every Design Engineer of Rail Vehicles Should Know About EN 45545

Key Cold Weather Design Factors for Connector Technology in Rail

Pneumatics Technology Enhances Profitability in Rail Applications

Source: Parker Feed