7/29/2019 topic 18c

1/5

1994 by Alexander H. Slocum

18-50

Aesops1 Surface Self Compensated Profile

The HydroSpindleTM

Very high accuracy, very low spindle error motions (sub-micron).

High stiffness and load capacity. No wear, potentially infinite life. Self cleaning bearing surfaces. High damping: excellent vibration and shock resistance. Patented shaft-surface groove geometry eliminates

cavitation and minimizes turbulence.

7/29/2019 topic 18c

2/5

1994 by Alexander H. Slocum

18-51

Belt-Driven Grinding Spindle

Shaft Diameter 3.5 inchesFluid CoolantSupply Pressure 600 psigClearance on Radius 0.0008Radial Stiffness at the Wheel 1.3 lbf/minAxial Stiffness 2.1 lbf/minMeasured Dynamic Run-Out 14 min

ShaftSpeed(rpm)

ShearPower(kW)

FrontBearing

Temp Rise(C)

0 0 1.02000 0.3 1.54000 1.5 3.46000 3.7 6.78000 7.0 11.5

7/29/2019 topic 18c

3/5

1994 by Alexander H. Slocum

18-52

Integral Motor-Driven Milling Spindle

Spindle Characteristics

Fluid Coolant

Maximum Operating Speed 50,000 rpm

Tool Holder HSK-A 40

Shaft Diameter on Radial Bearings 45 mm

Thrust Bearing Outer Diameter 56 mm

Radial Bearing Clearance 0.0008 on radiusThrust Bearing Clearance 0.0007 per side

Supply Pressure 1000 psig

Radial Bearing Temp. Rise @ 50,000 rpm 17C

Thrust Bearing Temp. Rise @ 50,000 rpm 8C

Total Bearing Drag @ 50,000 rpm 4.5 kW

Total Bearing Drag @ 40,000 rpm 9.5 kW

Total Bearing Drag @ 50,000 rpm 17.5 kW

Radial Stiffness at front spindle face 1.4 lb/minAxial Stiffness 2.0 lb/min

7/29/2019 topic 18c

4/5

1994 by Alexander H. Slocum

18-53

Spin-Off Application: TurboToolTM2

Advantages: Disadvantages:

Higher speed enabled. Tool holder eliminated. Reduced cost of machine crashes. Higher machining accuracies

achievable. Spindle thermal sensitivity and

thermal errors greatly diminished.

Through-tool cooling is possible. Reduced tool chatter and increased

depth of cut are expected.

Higher Acc/Dec rates enabledbecause the spindle is light.

High speeds and powers arepossible that are not otherwiseachievable.

Fluid supply system isexpensive ($90k - $130kfor a 100,000 rpm, 100kW system).

Overall power deliverysystem is not as efficientas an electric motor drive.

Reduced speed control (ifvalve system is not used).

Bulky hoses if lowpressure, high flow ratesystem is used.

2 U.S. Patent awarded, number not assigned yet. Other patents pending.

7/29/2019 topic 18c

5/5

1994 by Alexander H. Slocum

18-54

Power Capability of the TurboToolTM

Tool is 25 mm diameter, 100 mm long. 100 kW of net machining power available at 100,000

rpm.