Highly Flexible Bearing Grinder
We recenty supplied a new Usach 200-T4 grinding machine to an leading U.S. manufacturer of power generating technology.
The new machine allows this customer to grind all required ID and OD feautes of their bearing rings on one machine rather than running them on multiple machines as they did in the past. This high level of flexibility was accomplished by equipping the machine with the following features:
- High precision indexing turret with two high frequency spindles for ID grinding and one motorized spindle for OD grinding with wheels up to 16" diameter
- Rigid radius dresser with CNC swivel movement for single point or rotary dressing for radius and gothic ball races
- Dresser turret to efficiently swutch between radius dresser, stationary single point and stationary rotary dressers
- CNC workhead swivel axis with high precision Heidenhain rotary encoder feedback allowing for angular positioning of workhead, taper grinding and automatic taper corrections
CNC Radius Grinding
CNC Workhead Swivel Axis
Helical Blade Grinding
We supplied new grinding machines to an industrial turf maintenance equipment manufacturer. This manufacturer has long been known as a builder of the finest quality mowing equipment for the turf maintenance industry used on golf courses around the world.
The technology resulting from this collaboration produces reels with larger angles on each blade, which allows them to stay sharper for up to three times longer than reels available from competitors.
During operation these reels generate less friction which in turn produces less heat and wear compared to those of other manufacturers. This significantly extends the life and performance consistency of each reel.
As is typical of Usach projects, in addition to the machines, we provided process development, wheel specifications and implementation of CBN technology. The resulting new technologies allow for a single clamping process eliminating the need for multiple set-ups and grinding cycles per part.
Screw Compressor Rotor Grinding
The required grinding operations for screw compressor rotors consist of OD grinding all journals on both sides (some of which are tight tolerance bearing journals), the major OD and one shoulder adjacent to the major OD.
Prior to the purchase of our machines the customer used conventional OD anglehead grinders. The anglehead approach produced a poor geometrical part quality for the shoulder grinding operation. In addition, using their previous machines required that the part be turned around in mid cycle (no small feat considering that some of the rotors weigh up to 600 lbs.). Furthermore, these machines used conventional grinding wheels that required frequent dressing (at least once per cycle).
Our customer was looking for a new solution that would allow the rotors to be processed in one operation while improving part quality and cycle times. All of these requirements were accomplished with two new Usach machines.
To eliminate the need to turn the part around in mid-cycle, the grinding is accomplished with the use of a single vitrified CBN wheel. Since the parts are made of cast iron, which is a soft material, a special bond structure was developed to be able to withstand the bond erosion typically seen when grinding soft materials using vitrified CBN wheels. Using a straight wheel approach, this wheel can perform both OD and shoulder grinding operations. With its large diameter of 24”, the wheel clears the major OD allowing to reach the smaller diameter journals on both sides of the rotor.
A high pressure wheel scrubber is used to clean the wheel during the grinding operation allowing grinding of up to 150 rotors between wheel dressings. When dressing is required, only very small amounts of CBN are removed providing for a very long wheel life.
The cycle times have been improved with the ability to grind all operations in one clamping, the elimination of frequent dressing and the fact that material can be removed faster with the use of CBN wheels.
Since the installation of the two Usach machines, the customer has been able to not only maintain the new process but to further improve it by reducing the cycle time thus increasing production without adding more machines.
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