Seminar of ATSS

In January 25-th 2007 in 7:00 PM

Address: 4600 Bathurst Street (Lipa Green Building), Room 421 1

The first speech was delivered by Dr. Alexander Tchouvakov , the subject is “Development of small size pneumatic machine with turbine drive gears”

Authors:

Yuriy Kuznsov, Dr. Sc. in Techniques, Professor

Alexander Tchouvakov, Ph.D. in Techniques

Vladimir Himich, Dr. Sc. in Techniques, Professor

State Technical University of Nizhniy Novgorod

FORMULA (The Innovation Company), Russia

Pneumatic tools have various purposes and parameters such as their mass, capacity and idling speed. Air turbines may be considered to be optimal drive gears for grinding and polishing manual machines operating at rotation frequency from 60,000 to 120,000 rpm with abrasive wheels having 3…10 mm diameter.

Small size turbines differ from regular ones, first and foremost, with aerodynamic configuration of their stages. Thus, working fluid, having three-dimensional structure into axial turbines, yields to modeling and computation very poorly. Moreover, turbine’s nozzle channels of small turbines have very little square area. It renders impossible to study structure of the gas stream into the stages by measuring their local parameters.

Small axial turbines possess the following distinguishing features: Relatively big axial gap between nozzle diaphragm and turbine wheel Relatively thick edges and small heights of nozzles and working blades Relatively big angular length of the nozzles (up to 30^°)

Our design solutions based on analysis of merits and demerits of existing pneumatic tools with turbine drive gears. Relatively large efficiency of supersonic nozzle blades was achieved by enforcing their directional influence in the developed turbine stages. Testing of our machines revealed that they outmatched existent tools with balance of the main characteristics: power and air consumption. Moreover, consumer appeals of our machines, namely: small mass and size, convenience for operation and adaptability to mass production were achieved by unique aerodynamic configurations of turbine stages.

Advantages of the proposed turbine pneumatic tools determinate by: Compact centrifugal entrance of gas to the turbine stage through inside part of the nozzle diaphragm combined with axial flow exit from it

Combination of gas consumption regulator an nozzle diaphragm as an integral unit in tiny size machine (Patents of Israel No. 138482)

Arrangement two working blade crowns on one integral turbine wheel in small and regular size machines (Patents of Russia No. 34643 and 34644)

Possibility to make almost all parts of the machines by casting

Project status

Prototypes of the tools were made and successfully tested

Unique units of the machines were defended with patents

1. MACHINE OF TINY SIZE: Patent of Israel No. 138482

The described turbine was designed for application in tiny size tools. Proposed machine includes (see fig. 1) nozzle diaphragm 2 having a form of a ring inside front casing 1 and rotor 6 with axial turbine wheel 4 inside back casing 5. Inlet assembly includes fluid entrance hole 3 disposed inside nozzle channel 7. The nozzle diaphragm possesses ability to tangential moving relatively mentioned hole in order to gas consumption regulation.

Fig. 1

Estimated characteristics of small size machine:

Weight is 0.09 kg, maximal casing diameter is 0.95” and casing length is 4”

2. MACHINES OF SMALL AND REGULAR SIZE: Patent of Russia No. 34643

The described turbine was designed for application in small and regular size tools. Proposed machines include (see fig. 2) back casing with inlet channel having a device of gas consumption adjustment; front casing; double rimmed turbine stage. The radial turbine stage included double rimmed turbine wheel 1, centrifugal nozzle diaphragm 2 and directing diaphragm with axial blade crown 5. The turbine wheel had first (centrifugal) blade crown 3 situated on its back side and second (centripetal) blade crown 4 situated on its front side. Inlet assembly is situated inside the nozzle diaphragm.

Fig. 2

Estimated characteristics of small size machine (see fig. 3): Weight is 0.12 kg, maximal casing diameter is 1.4” and casing length is 4.2” Estimated power is about 200 Wt when inlet air pressure is 6 At Estimated idling frequency (in no-load operation) is 80,000-100,000 rpm

Estimated characteristics of regular size machine (see fig. 4):

Weight is 0.35 kg, maximal casing diameter is 2.1” and casing length is 4.7”

Estimated power is about 500 Wt when inlet air pressure is 6 At

Estimated idling frequency (in no-load operation) is 50,000-60,000 rpm

Fig. 4

3. PROSPECTIVE TURBINE DRIVE GEAR: Patent of Russia No. 34644

This turbine stage differs from the stage of the Patent No. 34643 with aerodynamic configuration of its outlet part. The second working blade crown of double rimmed turbine wheel is situated on cylindrical surface of the wheel opposite the axial blades of the directing diaphragm. This stage (see fig. 5) should possess bigger torque then the stage (fig. 2). Its application in relatively powerful tools seems very effective.

Fig. 5

The second speech was delivered by Eng. Maik Korol , the subject is: “Magnets and magneto therapy devices”. He has presented the different kind of production of Japanese company “…” such as: magnetic bracelets, massage tools, mattress, insole, etc.