jsburger wrote:Thanks Everett! I am sure someone will reply that has more knowledge than you or I.
John, As I said, I have never worked with 3 Phase Motors before, but here’s some DVR data from Teknatool about the DVR technology...
http://teknatool.com/dvrm/WhatIs.htm
POWERFUL AND EFFICIENT:
The DVR’s micro-computer automatically detects the load on the output shaft, and adjusts power extraction according to the load. As a result, the DVR motor has its highest torque at lowest speed and has a flatter torque curve over a wide range of speeds.
This unique characteristic means the DVR motor can be mounted directly to the output shaft, which allows it to achieve better output by eliminating the power lost in a traditional gears/belts and pulley drive system. (Typically, a belt driven machine has about 20% power loss just in the belt system alone!) When the shaft is under a light load, the micro-computer will reduce the power extraction to save energy. Combine this with the energy saving from eliminating the belt and pulley system, and the DVR motor can save up to 80% energy over a conventional AC motor.
EXTENSIVE SPEED RANGE:
A key advantage of this motor is its wide speed range. DVR Motor Technology has the capability to handle speeds from as little as 100rpm, right through to 10,000rpm, all in a versatile, compact package. (AC motor with inverter is only optimized at 1,500rpm).
SAFETY:
The DVR motor is monitored by the micro-computer constantly. In case of a sudden spindle lock, or unexpected sharp increase in load, the motor will automatically shut down power to the spindle to avoid any injury. There is further potential with this DVR motor to implement many more safety features determined by each customer’s requirements.
CUSTOMIZABLE:
Our standard DVR motor will be able to be used unmodified for many different applications straight off the shelf. But our DVR Motor Technology can also be customized to suit your individual requirements. Adjustments such as Power Rating, Human Machine Interface (HMI), Speed Range, Safety Features, and much more.
RELIABLE:
The Teknatool International group has already been researching and using this motor technology for over 10 years. Sold as a Wood lathe Motor under the reputable NOVA brand name, the DVR motor has had proven success in dusty and demanding conditions in all kinds of environments in all corners of the globe; from freezing Alaska and Iceland, to tropical Australia and Central America.
John,
Also in reading through their data some of the key points in DVR not present in AC or DC motors are:
Max Torque on the spindle over the entire speed range
No need to use belts or pulleys to achieve desired speed changes
Extremely efficient power performance
No rotor windings to overheat and fail – the rotor has no current flow thus no heat
No brushes to wear out
Quiet and vibration free
Computerized motor can fault sense and shutdown
Standard drives available in 1250W & 2500W shaft output and other sizes from 50w to 500KW
Models available that can run 30,000 RPM
Very green technology that runs 80% more efficient than an AC motor, and that would track just as well to 3 phase I suspect.
In essence: The Rotor (the rotating part of the motor) is just solid steel laminations, pressed onto the spindle. The Stator (the outside power coils) provide intense magnetic force to turn the spindle.
Read more on the topic at
http://teknatool.com/dvrm/
You will find it used also in the NOVA DVR Wood lathe… This is where Shopsmith excels… 7 in 1 tool with DVR across the board, opposed to a dedicated lathe… it’s where Shopsmith always has shined brilliantly…
Everett
Shopsmith DVR Motor Case Study by OEM Maufacturer Teknatool USA.pdf