The ability of Barbour Stockwell, Inc’s drive systems to provide ultra-high rotational speeds with precise speed control is the company’s key advantage in powering spin tests or driving the components in other test rigs. Whether an air turbine or electric motor drive, tests are conducted under the precise control of our TC4 controller with the test programming convenience provided by our SPIN3 software.

The air turbine system is generally a less costly investment than the electric motor; particularly if an air system already exists. However, the electric drive will be more economical to operate since there are fewer energy conversions required in driving and the energy stored in the rotor at speed can be returned to the mains when braking. Nonetheless, each system has its place depending on the application requirements and economics.

 

Air Turbines

In addition to the Tangential Turbines historically supplied for spin testing, BSi has developed a line of Radial Inflow Turbines for meeting the demands of applications requiring very high power at very high speeds.

Types of Air Turbines

The Tangential Turbine has buckets milled into the periphery of the disk – flow enters and exits tangentially.   Since there is no exposed blading the rotors are virtually indestructible and allow for bi-directional operation.

Radial Inflow Turbines are just that.  Flow enters radially and exits axially.

TANGENTIAL

  • EXTRAORDINARILY ROBUST – WELL SUITED TO THE RIGORS OF SPIN TESTING
  • CAN BE BIDIRECTIONAL
  • BIDIRECTIONAL CONFIGURATION YIELDS VERY EFFECTIVE BRAKING
  • LOW SPECIFIC SPEED MACHINES – GOOD PERFORMANCE ONLY AT RELATIVELY LOW POWER LEVELS.

RADIAL INFLOW TURBINES (RIT)

Radial Inflow Turbine Cross-Section

  • HIGHER EFFICIENCY
  • HIGH PERFORMANCE AT HIGH POWER LEVELS. E.G.:
    • 130 HP AT 130,000 RPM
    • 800 KW AT 50,000 RPM

The Radial Inflow Turbines are generally designed specifically for each application. Standard models exist, on the other hand, for the company’s Tangential Turbines. They are categorized by the diameter of the turbine rotor disk. Standard models exist for spin test service and for driving other rigs.

As can be seen in the cross-section below, BSi’s Radial Inflow Turbine design employs a two-sided turbine wheel.   This unique configuration provides some important advantages.

  • Typical single-sided RIT wheels are subject to generating thrust loads due to the differences in pressure between the wheel gas path and backface. These loads can be very large and will fluctuate wildly through the operating envelope. The symmetry of BSi’s design eliminates the possibility of any thrust loading at all.
  • The RIT efficiency is enhanced. There are no backface windage losses since there is no backface!
Size
(in.)
Maximum Speed
(rpm)
Rig Drive Model Spin Test Models Max. Spin Test
Weight (kg)
1.25 200,000 2100 deriv. 2100 2
1.5 150,000 1500 deriv. 1500 4
2 100,000 7890 deriv. 7890 50
4 60,000 6000 2775 / 9552 100
5 50,000 5500 deriv. 5500 400
6 40,000 6700 6100 / 7700 400
8 30,000 8700 4146 / 7950 700
14 18,000 8000 7000 1800
20 12,000 9100 9000 3600

 

Electric Drive Systems

BSi Electric Motor High-Speed Drive systems employ High Speed, High-Efficiency Motors with sophisticated Direct Torque Control Drives. When required, speed is increased with the BSi engineered gearing. Spot on speed control is assured by virtue of our TC4 controller working with the motor drive.

BSi electric drive systems meet all CE Standards and Norms. Moreover, they reduce utility demand charges and introduce less harmonic distortion in the power supply than conventional DC drives.

AC MOTORS

  • HIGHEST EFFICIENCY – OVER 90% AT BASE SPEED
  • DEVELOP FULL POWER AT 50% RATED SPEED
  • PRECISE SPEED CONTROL
  • DIRECT TORQUE CONTROL DRIVES
  • PROPRIETARY TC4 CONTROLLER WITH PROPRIETARY SPEED CONTROL ALGORITHMS

GEARBOXES DESIGNED AND BUILT BY BSi

  • DUAL RATIO – MAXIMUM TORQUE FOR THE LARGE, LOW-SPEED TEST ARTICLES
  • HELICAL FOR QUIET OPERATION AND LONG GEAR LIFE
  • DOUBLE HELICAL – ELIMINATES THRUST LOADS TO EXTEND BEARING LIFE

Drive Systems from Barbour Stockwell Inc.

The air turbine drive system should be considered when the application is not particularly energy-intensive; e.g., testing very small test particles at very high speeds, particularly if the throughput is not great.  The electric drives are clearly superior, on the other hand, for operations requiring the testing of very large test pieces or for Low Cycle Fatigue testing.

For additional information, please contact us today!