High speed grinding spindle
First Claim
1. An apparatus for grinding a workpiece comprising:
- a grinding wheel spindle assembly having a rotary wheel spindle, and a grinding wheel attached at one end of said wheel spindle;
a wheel spindle motor connected to rotationally drive said wheel spindle at a first revolution speed effective for feed grinding and at a value different from that corresponding to a first resonance frequency of said wheel spindle as determined when said grinding wheel is in pressure contact with the workpiece to thereby feed-grind the workpiece and to rotationally drive said wheel spindle at a second revolution speed lower than said first revolution speed and at another value different from that corresponding to a second resonance frequency of said wheel spindle as determined when said grinding wheel is in spark-out operation;
a speed controller coacting with said wheel spindle motor to effect rotation of said wheel spindle at said first revolution speed and responsive to a detecting signal to effect rotation of said wheel spindle at said second revolution speed;
workpiece supporting means for supporting a workpiece and being movable relative to said grinding wheel spindle assembly; and
feed sensing means for detecting spark-out or finish of the feed grinding and providing a corresponding detecting signal which is transmitted to said speed controller to accordingly lower the revolution speed of said wheel spindle to said second revolution speed.
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Accused Products
Abstract
An apparatus for feed grinding workpieces comprises a workpiece spindle assembly for supporting a workpiece and a grinding wheel spindle assembly for supporting a grinding wheel, the two spindle assemblies being movable relative to each other to enable movement of the workpiece into pressure contact with the grinding wheel. A variable speed drive system rotationally drives the grinding wheel relative to the workpiece at a first predetermined speed of rotation different than the resonant frequency of the grinding wheel spindle assembly to effect feed grinding of the workpiece. Completion of the feed grinding or spark-out is detected after which the rotational speed of the grinding wheel is lowered to a second predetermined speed different than the resonant frequency of the grinding wheel spindle assembly when operating in the spark-out mode. The high speed rotation during feed grinding assures good grinding quality and the low speed rotation during spark-out assures good surface finishing. By rotating the grinding wheel spindle assembly at speeds other than its resonant frequencies, damage due to large vibrations of the assembly is avoided.
87 Citations
11 Claims
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1. An apparatus for grinding a workpiece comprising:
- a grinding wheel spindle assembly having a rotary wheel spindle, and a grinding wheel attached at one end of said wheel spindle;
a wheel spindle motor connected to rotationally drive said wheel spindle at a first revolution speed effective for feed grinding and at a value different from that corresponding to a first resonance frequency of said wheel spindle as determined when said grinding wheel is in pressure contact with the workpiece to thereby feed-grind the workpiece and to rotationally drive said wheel spindle at a second revolution speed lower than said first revolution speed and at another value different from that corresponding to a second resonance frequency of said wheel spindle as determined when said grinding wheel is in spark-out operation;
a speed controller coacting with said wheel spindle motor to effect rotation of said wheel spindle at said first revolution speed and responsive to a detecting signal to effect rotation of said wheel spindle at said second revolution speed;
workpiece supporting means for supporting a workpiece and being movable relative to said grinding wheel spindle assembly; and
feed sensing means for detecting spark-out or finish of the feed grinding and providing a corresponding detecting signal which is transmitted to said speed controller to accordingly lower the revolution speed of said wheel spindle to said second revolution speed. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- a grinding wheel spindle assembly having a rotary wheel spindle, and a grinding wheel attached at one end of said wheel spindle;
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10. An apparatus for feed grinding a workpiece comprising:
- a rotatable grinding wheel spindle assembly having a grinding wheel;
workpiece supporting means for supporting a workpiece to be ground;
means for moving the workpiece into pressure contact with the grinding wheel;
driving means for rotationally driving said grinding wheel relative to the workpiece at a first predetermined speed of rotation different than the resonant frequency of said grinding wheel spindle assembly as determined when it is in pressure contact with the workpiece so as to effect feed grinding of the workpiece and responsive to a detecting signal for rotationally driving said grinding wheel relative to the workpiece at a second predetermined speed of rotation lower than said first and different than the resonant frequency of said grinding wheel spindle assembly as determined when it is not in pressure contact with the workpiece; and
detecting means for detecting completion of the feed grinding of the workpiece and developing a corresponding output detecting signal and applying said detecting signal to said driving means to thereby effect rotational driving of said grinding wheel relative to the workpiece at said second predetermined speed so as to effect surface finishing of the workpiece;
whereby the high speed rotation of the grinding wheel spindle assembly during feed grinding assures good grinding quality and the low speed rotation during finishing assures good surface finishing while avoiding damage to the grinding wheel spindle assembly by ensuring that it does not rotate at one of its resonant frequencies. - View Dependent Claims (11)
- a rotatable grinding wheel spindle assembly having a grinding wheel;
Specification