Valve Grinding Machine

for valves with stem diameter
up to 40mm


Due to its solid construction, the VKM4A is particularly suitable for continuous operation in maintenance factories.


   Valve stem diam.      9 - 40mm
   Max. valve head diam. 320mm
   Valve seat angle 0°- 90°
Grinding spindle:  
   Grinding wheel diam.   250mm
   Speed at 50Hz 2800rpm
Work spindle  
   Speed at 50Hz 5 - 50rpm
Coolant system:  
   Coolant capacity 12 liters
Power requirement:  
   Supply voltage 400V±10%
   (3ph 50/60Hz)             or 230V±10%
   Power input 2kW
   Length 1550mm
   Width 900mm
   Height max. 1250mm
   Net weight 300kg


Machine base:
Heavily ribbed cast iron structure for vibration free performance.
The machine base houses an industrial type flood pump for delivering coolant to the grinding site and a baffled coolant tank which can be drawn out for ease of cleaning.

Wheel head:
Box type monobloc casting noted for its excellent vibration damping characteristics.
The precision grinding spindle is permanetly sealed and lubricated for lifetime accuracy.
The powerfull spindle drive motor in combination with the 250 mm diameter grinding wheel allows fast stock removal. The wheel guarding system is designed to the prevailing safety regulations.

Cast iron monobloc for vibration free performance. Rigid support of the work spindle on precision bearings. The work spindle is fitted with a collet chuck for use of high precision collets.
The variable speed work spindle drive unit is mounted on top of the workhead.

Swivel plate:
The workhead rests on an elongated swivel plate mounted on the work table.
The swivel plate can be set to the required angular position by means of a widely spaced scale.
Index stops with micrometer adjustment are provided at 30° and 45° positions.
The swivel plate has a dovetailed slideway allowing the workhead to be adjusted along the swivel plate to chuck the valve at that part of the valve stem which normally travels in the valve guide.

Work table:
The infeed slide on top of the work table is guided by a dovetailed slideway provided with an adjustable strip for long term accuracy.
The worktable itself is guided on slide bars to ensure smooth traversing of the valve face across the grinding wheel.

Dressing attachment:
The dressing attachment is housed in the wheelhead for rapid wheel dressing, also during grinding with the valve chucked in the work spindle. An individual handwheel is provided for traversing the diamond along the grinding wheel.

Selfcentering steady:
Selfcentering steady rests are available to fit on the swivel plate slideway for additional support of long stem valves.
Both the workhead and the stready rest are adjustable along the swivel plate to clamp each valve on that part of the valve stem which normally travels in the valve guide.
The combination of collet chucking and the unique Hunger steadying provides double support of long valves to ensure the ultimate in valve refacing accuracy.

Oscillating equipment, mechanically operated:
An oscillating equipment for automated power traverse of valve face across the grinding wheel is available to ensure efficient stock removal and superior finish.
The stroke of oscillation is infinitely adjustable.
Not applicable when installing the digital automated infeed and oscillating system.

Ball Bearing Spindle System (Option):
for heavy-duty use of oscillating grinding. The ball bearing spindle performs the precise longitudinal movements of the workhead.
Required for digital automated infeed and oscillating system.

Digital automated infeed and oscillating system (Option), since 2023 a new version is available:
Power infeed is available for automatic grinding according to a preselected program.
The feed rate, the total infeed, the stroke of oscillation and the sparkout time can be easily selected.

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