March 2006Pneumatics & Hydraulics
Integrated Solutions
South African pneumatics specialist, Festo, has taken on the project of designing a pulley tensioning device for a Magni Gyro autogyro.
Festo was approached to develop and install a replacement device for a manually activated jockey pulley tensioning device on the autogyro. The tensioning device provides tension between two fan belts running on a set of pulleys leading from the crankshaft to the top rotor starting pulley. During start up the top rotor is brought into motion with the aid of engine power. After this initial start up, the forward motion of the autogyro keeps the rotor in motion and acts as a 'wing' to keep the autogyro in the air. The factory-fitted device comprised a lever similar to those used on a bicycle brake connected to a cable leading to the jockey pulley tensioning device. A solution was required that enabled the pilot to control this start up procedure via a switch located on the steering stick.
Figure 1. Air is delivered to the 16 mm diameter standard cylinder causing a slow pulling action
According to Bruce Rainbird, Festo internal sales, this was accomplished using pneumatic control.
"The operational control was the most challenging to design into the tensioning device as progressive tension on an incremental basis was required in order to ensure a smooth as well as incremental transfer of power to the main rotor pulley. Once the main rotor was at a desired speed, the power transmission (tension on v-belts) had to be immediately released that is, slow incremental and controlled tensioning with a spring return."
Figure 2: Festo utilised a normally open solenoid valve, normally closed solenoid valve, 16 mm diameter standard cylinder, non return valve, and one-way flow control valve as the main components of the design.
Festo used a normally open solenoid valve, normally closed solenoid valve, 16 mm diameter standard cylinder, non return valve, and one-way flow control valve as the main components of the design. Rainbird explains: "As soon as power is delivered to the system, the normally open valve would close allowing air-pressure from the pilot side of the non return valve to fall away ensuring air-flow in only one direction. By activating the normally closed valve (toggle switch), air is delivered via the one way flow control valve and the non return valve to the cylinder causing a slow pulling action."
If the toggle switch is released, air delivery is stopped and the piston position is retained by the non return valve. If more tensioning is needed the toggle switch is activated and air delivered to the cylinder. On completion of the start up procedure, the power to the system is switched off, the normally open solenoid returns to open and pressure is delivered to the pilot side of the non return valve allowing air to escape from the cylinder at a rapid rate ensuring the 'spring return'.
A major safety benefit from the switching off on de-activation is that the procedure cannot be activated in flight thus avoiding any possible damage.
An autogyro is so named because it is an aircraft that derives its lift from an un-powered main rotor that windmills freely under autorotation. To climb, or remain aloft, the autogyro is most often thrust forward by means of a pusher propeller at the rear of the machine. To shorten the take-off run, some autogyros are equipped with a pre-rotation mechanism that allows power from the pusher-engine to be used to get the main rotor up to speed before commencing the takeoff run. On a more trivial note, just as aeroplanes are called 'airplanes' by some folk, autogyros are also called 'gyrocopters', which loses the original derivation by dropping the 'auto' - Ed.
Supply chain attacks have become an industry of their own
Information Security Integrated Solutions Logistics (Industry)
Organisations face a fundamental change in supply chain risk. Opportunistic attacks are becoming increasingly systematic, with threat actors deliberately targeting trusted technologies and relationships that can give them access to multiple organisations at once.
Read more...One picture of the estate
Editor's Choice Integrated Solutions Security Services & Risk Management Residential Estate (Industry)
Bringing patrol, incident, and H&S reporting onto a single platform: a security operation should be able to show what happened, when it happened, and how personnel responded.
Read more...Electrically operated, energy-efficient double diaphragm pumps Bearing Man Group t/a BMG
Pneumatics & Hydraulics
BMG has introduced the EVO series 210 electric double diaphragm pump range from ARO, offering lower energy consumption and quieter operation than air-operated alternatives, with access from one side for both diaphragms, and optional electronic leak detection for critical applications.
Read more...Integrated Air Solutions opens KwaZulu-Natal branch
Pneumatics & Hydraulics
Integrated Air Solutions has opened a KwaZulu-Natal branch in Pinetown, establishing a local turnkey compressed air partner for the province with equipment, installation, servicing, rapid emergency response and rental offerings under one roof.
Read more...Connecting access control, logistics and asset tracking SA Technologies
Access Control & Identity Management Integrated Solutions Residential Estate (Industry) Logistics (Industry)
Physical barriers matter, but a site is not secure just because the gate is strong or the container is locked. True security requires verifying every movement, tracing handovers, making exceptions visible, and allowing intervention before minor issues become major losses.
Read more...Optimising access control and the right to privacy neaMetrics Suprema IDEMIA Technews Publishing SMART Security Solutions
Editor's Choice Access Control & Identity Management Integrated Solutions Residential Estate (Industry)
How can access be controlled more efficiently without disrupting the estate or creating endless queues in the visitor lane(s), while also adhering to the draft Code of Conduct?
Read more...Precision and durability in metal manufacturing and injection moulding Parker Hannifin - Sales Company South Africa
Pneumatics & Hydraulics
From 800 bar hydraulic circuits in metal presses to low-pressure cooling systems in injection moulding machines, Parker Hannifin’s fluid connector systems are engineered for the contrasting demands of high-pressure sealing, thermal resistance and rapid serviceability.
Read more...Turning compressed air into a strategic energy advantage
Pneumatics & Hydraulics
Compressed air accounts for up to 80% of a system’s lifecycle costs, yet often remains overlooked in energy strategies. CompAir’s Energy Check provides a data-driven analysis of the complete compressed air network to identify energy savings of 20 to 30% or more.
While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.
printer friendly version