 |
| Powered by phpBay Pro |
why does an electric knife have a nylon gear and a steel worm?
All the previous answers miss the salient reason for the design engineer's choice of materials.The worm is usually of a small diameter, but designer often wishes the knife to able cut in arduous situations [though frozen meat for example] the loading imposed on a small diameter nylon worm gear would cause elevated wear rates and hence failure of the drive very quickly. Steel is a cheap and strong, always the production engineer's favourite choice, minimising cost and maximising profit.
The driven gear is of a much larger diameter and the loading it experiences is less. The design engineer must consider the safety of the user of the knife and in this case he is worried about what would happen to the knife and its user if the knife blades where to jam. So for safety he chooses to use nylon [ or possibly PTFE, Tufnol or similar materials, even wood in some cases ] so that in a jam fault situation, the loading exceeds the maximum designed working load and the gear teeth strip protecting the user from kickback or injury from the knife. This also prevents the electric motor from overheating as the motor is now allowed to free run.
On the better quality and usually more expensive knives there is usually also thermal fuse close to the motor in the power supply line, such that if the motor overheats under fault conditions the fuse blows and the power is removed from the motor.
|
 Brook Electric 15 HP AC Gear Motor FREE SHIPPING  US $1,857.00
|
 Cam Spray 2000 PSI Cold Water Electric Base Pressure Washer 2000GEAR US $1,789.99
|
 BOSTON GEAR ELECTRIC MOTOR 3HP US $1,700.00
|
 SEW DFT71 2 HP Electric Motor SEW Reduction Gear NEW US $1,075.00
|
 SEW DFT80 1HP Electric Motor SEW Reduction Gear NEW US $1,020.00
|
 12V DC 15 RPM High Torque Gear Box Electric Motor New US $1,012.99
|
 12V 15RPM High Torque Gear Box Electric Motor New US $1,011.99
|
 12V 15 RPM High Torque Gear Box Electric Motor Small US $1,011.99
|
 12V DC 60RPM High Torque Gear Box Electric Motor 60 RPM US $1,010.49
|
 SEW DFT71 2HP Electric Motor SEW Reduction Gear NEW US $999.00
|
 SEW DFT80K Electric Motor SEW Reduction Gear NEW US $999.00
|
 SEW DFT71 75 HP Electric Motor Reduction Gear NEW US $999.00
|
 Baldor Electric Motor 1 hp 230 460 Volts 3 Phase With Ironman Gear Reducer US $625.00
|
 Sterling Electric 425B0015182 151 Gear Speed Reducer Power Transmission US $600.00
|
| Powered by phpBay Pro |