Rafamet UBB 112 CNC wheel lathe

Rafamet CNC WHEEL LATHE
COMMERCIAL INDUSTRIAL PARTNERS
CNC Double saddle Wheel Lathe for machining of wheel sets.
Application
The lathe type is a double saddle special purpose lathe designed for machining of profiles of wheels used in the rail vehicles. Rolling in and off the wheel sets
from the machine is carried out only from one side.

Basic dimensions and technical data
Track gauge
Max. wheel tread diameter
Min. wheel tread diameter
Max. length of wheelset axle
Min. length of wheelset axle
Max. tyre width.
Infinitely variable feeds of saddle
Speed of set up motions of saddles
Max. weight of wheelset
Power of main drive motor of infinitely variable speeds
Machine weight
Track gauge

Accuracy of profile machining
Ovality of wheel tread. max. 
Run out of wheel tread. max. 
Run out of inner side surfaces of wheel rim. max.
Difference of diameters of wheel tread of one wheelset max. Clearance between the gauge and machined surface of wheel profile. max. 
Achievable roughness of the machined surface. 

Machining capabilities
On the machine, the following jobs can be performed
Turning of profile on wheels according to the technological program.
Turning of inner side surfaces of wheel rim.
By adaptation of the machine and us of additional optional equipment, the following operations and works are possible. Turning of outer side surfaces of the wheel rim and turning of limit machining groove beyond the technological program by means of manual control from CNC panel.
Maching of tyre for dismantling of clamp ring beyond the technological program by means of manual control from CNC panel. Turning of outer friction side surfaces of brake discs, located on the inner part of the axle, near the wheels beyond the technological program by means of manual control from CNC panel.

Work in automatic cycles
The machine is adapted for work in the following subsequent cycles
Clamping of wheelset on the machine.
Positioning of saddles.
Measurement of profile.
Turning of profile.
Measurement of profile after machining.
Unclamping of wheelset.
Apart from working in automatic cycles, the machine can be manually controlled, cycle after cycle from CNC panel.
Technical description of machine
Body system the bed, made of cast iron, is provided with flat longitudinal guideways on which the headstocks travel. The bed guideways are made of steel blocks hardened and ground. The headstocks bodies are made of cast iron. The longitudinal travel along the bed guideways is carried out by means of motor through permanent transmissions and units screw nut. In working position, the headstocks are clamped against bed guideways by means of hydraulic clamps. The machine is equipped with two saddles, which by means of CNC system allow for turning the wheel profiles in an automatic cycle according to pre set technological program. Feed drive is carried out by means of motors of infinitely variable speeds and system of screw ball nut. The upper bodies of saddle are provided with compound double edge cutters for turning of wheel profiles. The cutters are adapted for mechanical fixing of with exchangeable cutting tips e.g. of SANDVIK COROMANT, PLANSEE makes.

System of wheelset clamping
The machine is equipped with hydraulic system
Lifting jack centring device for shifting the wheelset to the level of machine centres axis. After clamping the wheelset in the centres, the lifting jack and centring device retract automatically to initial position. The centred wheelset in the machine centres is clamped by means of three drivers with jaws. The jaws clamp the wheelset, displacing radially under the action of hydraulic cylinder. The jaw pin has exchangeable clamping inserts. The drivers are adapted for work in automatic cycles of wheelset clamping and unclamping, can also be controlled beyond the cycles, manually from control panel. The control and coordination of units motion is carried out by means of system of stops and electrical switches. The machined wheelset can be clamped and unclamped also beyond the cycle, by manual control from control panel.

Control system
The machine is fitted with control system, built on the basis of central unit of CNC system of SIEMENS make, type SINUMERIK 840 D. The system controls both saddles, from which each executes two travels, perpendicular one to another. Apart from controlling the saddles, the system controls all other operations of the machine, which are connected with the turning of wheel profıle. The machine is equipped with drive units for saddles of infinitely variable speeds. The saddle drives consist of AC asynchronous motors with pulse rotary transducers. Adjusting units. Control contact relay apparatus etc. is housed in control cabinet, located near the machine. The machine is provided with electrical interlockings, protecting particular sub units against accidental defects and emergency during the operation of the lathe.

Control panel
The central control panel, located on swivable pendant, is provided with CRT, necessary push buttons, light indicating system and indicators, necessary for safe
servicing of the machine. The values displayed on the CRT include L.h and r.h wheel tread diameter. Measured width and height of wheel flange. Cutting speed in m min.
Spindle speed in rpm. There is a possibility of loading the following other values
Number of machined profile.
Working feed.
Cutting depth for one pass.
Tyre width.
Off set of measuring heads.
Offset of cutting tools.
Max. and min. spacing of inner side surfaces of wheel rim. Value of machined tread diameter or depth of cutting layer. The control system is also equipped with diagnostics of machine work condition which inform also on disturbances in its operation. The diagnostic messages are displayed in text format on the CNC CRT.

Measuring positioning heads
Each saddle is fitted with measuring positioning head, through which the following is carried out setting of saddles in relation to the wheel. Measurement of wheel tread diameters. Measurement of thickness and height of flange. Measurement of wheel base. Others.

Hydraulic system
The machine is equipped with power hydraulics system which performs the following
Supply of lifting jack and centring device,
Clamping of headstock against bed guideways.
Radial pressing of driver jaws
Extension of ineasuring positioning heads.
The hydraulic system is supplied from separate pack, provided with two gear pumps. The operation of hydraulics is constantly controlled. Possible faults are signalled on the control panel. Adequate interlockings can stop the machine work and in danger, switch off the machine.

Additional equipment
Turn table for wheelsets
Totally enclosed guarding system