DUNKES – Experience on which
I can rely

  • Press stability
  • High availability of presses
  • Core competencies press construction
  • Reliable and robust press technology

Hydraulic wheel set press 

Wheel pressing and pulling press simplifies and speeds up the repair or assembly of rail-based vehicles.

 

Vehicles only make money when they are on the track! This fact also applies to a special degree for rail-based transportation equipment used by rail operators. Repair workshops are therefore particularly intent on repairing disabled vehicles with the greatest possible speed, so that these can be returned to passenger or freight service. In addition to qualified staff, this requires careful logistical planning, and also a workshop that is organised and equipped based on the latest considerations. The latter specifically applies when the repair components involve difficult to handle parts, such as entire wheel sets.

 

"Wheel assembly and repair" was also a topic of concern for a repair workshop operated by Bahn AG [Germany's public railway operator]. The shop was looking for a solution to simplify and speed up processing and handling of the wheelsets with weights up to 6 tonnes. In addition to the supply of a special wheelset press, the specification document included other deliverables, ranging from digging foundations to handling of repair components, and including an electronic measurement system with a quality inspection capability.

 

After intensive negotiations with potential suppliers, the proposal from Dunkes (Kircheim/Teck) prevailed. This Swabian machinery builder has many years of experience building hydraulic presses, and was able to provide quality references for its wheel set presses used by repair shops and railcar factories worldwide. Various custom plants also demonstrated that the mid-sized company has sufficient know-how and engineering capabilities to plan and build the forward-looking concept in the general contractor role.

 

The rail vehicle is lifted by crane for repair or routine inspection. The now freely accessible axle is secured by a custom bogie that also travels on the rails, which then transports the axle to the wheelset press after a washing cycle. When the feed rail and the wheelset press are not in line – for instance in multitrack repair shops – the tool bogie is first rotated on a turntable, for instance by 90°, in order to travel to the press. The delivered scope also includes a crane system. it removes the wheel sets from the tool bogie and positions them in the centre support of the press. The exterior shape and receivers of the support essentially correspond to the contour of the wheelsets. The exact shape of the respective wheel and disc brakes are formed by toolsets, which are included as a type specific deliverable, and ensure that the wheelset is supported on centre. The centre support has a very solid configuration, since it also functions as a counter support during the pressing operation. The casting weighs in at approximately 35 tonnes,and travels under motor power in the longitudinal axis, rendering it adjustable to the various wheel sets and the press-on or pull-off operations.
 

Before the pressing process, the axle is hydraulically set between centre stocks. The exact position of the wheelset is determined by a measurement system that swings in from above. Depending on the assembly task, it records the axle length, wheel gauge, wheelbase, distance between brake and wheel discs, etc., and forwards these dimensions to the control, which then controls the hydraulic cylinder feed motions.

The press cylinder then presses with a maximum force of 5000 kN against the axle and presses the wheel off the shaft. Inserts that match the axle cross section and the wheel to be pressed off are used as compression elements. A precision ram stroke and accurate ram motion control are of decisive significance for a controlled press-on or pull-off operation. The two servo controlled press cylinders are positioned at tolerances of +/- 0.02 mm in spite of the large compression forces. During the press operation, the wheel is held by a crane belt and subsequently transported from the workspace of the machine with the help of a gantry crane.

The plant is operated with a modern PC control based on Windows NT, which is integrated into a mobile operator panel. A printer that is also integrated into the operator panel logs and documents all quality control measurement values relevant for the pressing process. This log must be prepared for each operation, so that the category 1 safety component  can be returned to operational service.

The wheelset press with an overall weight of 120 tonnes is secured approximately 1.5 m below ground, and has been working to the customers full satisfaction. In connection with the transport, handling, and measurement facilities that were also planned and supplied by Dunkes, the overall wheel press-on and pull-off press concept was implemented in accordance with customer needs and placed into service approximately 12 months after order award, largely due to the delivery from a single source.

 

 

Dunkes hydraulic wheelset press of type RP 500 during assembly.
Wheelsets of various sizes are secured by the tool manipulator and brought to the press.
Associated products