There is a tremendous amount of innovation in the blades and the rotor. There also is a huge amount of industrial design in the appearance of the machine.
They do look good—warm, inviting, and as green as a green bean casserole. The blades are designed for maximum power, minimum swept area, and likely minimal air disturbance near the tips. If the machine delivers maximum power at 19 rpm, and the radius of the blades is 147.5 feet, the velocity at the tip of the blade is then 293 feet/second at full power.
The big question then becomes what’s next. How can power electronics and machine innovation impact these wonderful machines? The yaw actuators, blade pitch actuators, and prime mover seem like fertile ground for improvement if we look at the rotating machines. They all have large gear reduction ratios that source (or sink in the case of the prime mover) very high torque. But I don’t think that’s grounds to simply swing the gavel of innovation and demand that all of these machines go toward high pole count, permanent magnet (PM) synchronous machines, or any other solution for that matter.
The Yaw And Blade Pitch Actuators
Perhaps a direct drive PM machine is heavier than the existing technology. That sounds okay on the ground. But 300 feet in the air when you’ve crawled into the rotor and are breaking loose the bolts on a blade pitch actuator, lowering something that weighs less than the 300-lb actuator to the ground would be a welcomed advantage (about 150 lb of motor, about 150 lb of gearhead). Lowering a heavier load may lead to a few more expletives. The yaw actuators are similar in proportionalthough slightly heavier.
For the lightweight solution we can give credence to the aviation industry, which has mastered generating high torque with minimal weight in actuator applications. The aviation industry does this with very high-speed machines, perhaps with a Ke corresponding to 10,000 rpm or higher at maximum driven amplitude. The fast, lightweight machine then ties to a gearhead that delivers proper reduction.
Both the yaw and blade pitch actuators could see innovations along these lines. The motor would become much lighter, and the gearbox would stay about the same or perhaps get slightly heavier. The net weight loss would be a positive attribute, in addition to offering a more efficient system than the prior technology. But the reliability doesn’t take that quantum leap forward. Torque is still multiplied by the output gearing, so the main failure mechanism is still in play.
The high-pole-count PM machine could certainly deliver more torque in these applications and be more reliable since it requires no gears, but the weight of the machine (often driven by the back metal needed to contain the flux) would be prohibitive. This is where the argument comes in that the high-pole-count PM machine needs no gears and thereby doesn’t share the primary failure mechanism of the gearhead motor. For the added weight of the back metal, the failure rate drops substantially, perhaps to near ideal. One technology could be easily debated over the other: lightweight versus high reliability. If the machines truly live up to the 30-year serviceable lifetime, perhaps the heaver solution will dominate.
Read the full story at www.careel-laser-engraving-machine.com web! Four product lines to meet your Laser engraving, Laser cutting, Laser marking, welding and carving application. If need any help, please contact our Sales Team or Technical Team, they can support you well.