We define “SCR Rated” as a permanent magnet DC gearmotor that is designed to operate with an unfiltered SCR speed control while delivering similar speed and torque performance as a PMDC gearmotor that is designed to be operated from a filtered DC speed control or from a PWM speed control. SCR rated PMDC gearmotors or motors are designed to remain within their safe operating temperature range while delivering full rated torque over the entire speed range (when operated with an unfiltered SCR speed control). This is in contrast to PWM-rated PMDC gearmotors or motors which would need to be operated at reduced torque if they were operated with an unfiltered SCR speed control.
The majority of our standard stock 130V PMDC motors and gearmotors are rated for operation with a filtered speed control (FF = 1.0) at an armature speed of 2500 rpm. When operated with an unfiltered SCR control (90VDC off 115VAC), these stock motors will run at an armature speed of approx. 1725 rpm and would have to be proportionally derated. Hence, offering 90V or 180VDC “SCR Rated” gearmotors with an armature speed of 2500rpm allows the user to use the same gearmotor and gear ratio with either a winding for a filtered (PWM) or unfiltered SCR controls.
Form Factor for a DC speed control is a measure of the amount of current (ampere) filtering (smoothing) provided by the control to a motor. Form Factor cannot be determined until a motor and control combination are driving a load. However, most control manufacturers catalog their controls with a FF rating. Most small motor and control combinations exhibit FF= 1.0 to 1.05 with a filtered control and FF= 1.6-1.8 with an unfiltered control at rated torque.
Bodine permanent magnet DC motors in this catalog are rated for continuous duty on 130 VDC, FF=1.05 current as supplied by Bodine type FPM and WPM controls. These motors and gearmotors can be successfully operated from unfiltered controls at FF=approximately 1.6, at speed not less than 1700 rpm. For intermittent duty operation, full nameplate torque may be available. The designers should test for each individual application.
All motors and gearmotors shown in our catalog are reversible. To prevent gearing damage, most gearmotors require a full stop before reversing.
Obtainable torque is the maximum output torque (peak torque) for a gearmotor. Gearmotors may be operated at these levels only for brief periods due to thermal or mechanical limitations.
All rated torques shown in our catalog are for continuous operation. Continuous duty products can be used intermittently. Operation at loads higher than nameplate ratings is possible for short periods as long as there are rest periods for cooling. Loads higher than obtainable torque for gearmotors are never recommended. The temperature of the motor should be monitored during testing to make sure it is not overheating
The winding type is shown on the heading of each selection table for each product. It is also included in the Bodine Frame Type as a 2 letter code. On a motor, it is the last 2 characters. For example, Bodine Frame Type 42A5BEPM is a "PM" or Permanent Magnet. On a gearmotor, it is the 2 characters before the dash (-). For example, Bodine Frame Type 34R6BFCI-W2 is a "Cl" or Permanent Split Capacitor Motor. The Technical Discussions at the beginning of each section in our catalog provide more information on the characteristics of the winding types in the section.
Three phase (PP), 3 phase synchronous (YP), and some Permanent Split Capacitor (Cl) designs may be operated as adjustable speed with suitable controllers.
Adjustable speed systems are sometimes appropriate for single speed applications. If the desired speed is not known or not offered in a single speed product, an adjustable speed system may be set to the desired speed. For a low volume requirement, this approach will normally be more cost effective than changing ratios or making up special gearing.
A synchronous motor is an induction motor that operates directly from AC power and rotates at an exact multiple of the line frequency. Common synchronous induction motor speeds on 60 Hz are 1800 and 3600 RPM.
IP number is an international system for rating enclosures. An IP-44 rating is roughly equivalent to NEMA 12 for dust and water resistance.
Self locking refers to the tendency of some gearing to resist movement when the gearmotor is at rest and the load is attempting to move. An example is a load on a conveyer belt trying to drive the system backwards.
Parallel shaft gearheads and right angle gearheads with low ratios are generally not considered to be self locking. Right angle gearheads with ratios greater than 20:1 are often considered to be self locking. They will resist movement up to their torque rating. As the gearing nears the end of its useful life or if it is subjected to overload conditions, it may wear to the point where it is no longer self locking. Self locking gearing is not a recommended method for preventing movement in applications where this movement may cause injury or damage. An external brake is recommended for those applications.
Motors without gearing and K-2 gearmotors may be operated in any position. Standard Bodine gearmotors are designed for universal horizontal mounting with the motor portion or the drive shaft horizontal. Other mounting positions are possible, depending on the gearmotor type (and lubricant). Some gearmotors are oil lubricated. If these gearmotors are mounted in a position other than horizontal, the oil might find its way out of the gearbox as the motor shaft or the shaft seal wear out over time. When in doubt, please consult our technical support staff in Northfield (Chicago area).
A motor designed for 60 Hz operation will run at 5/6 rated speed on 50 Hz. For example, a motor rated 1700 RPM on 60 Hz will run at 1400 RPM on 50 Hz. Bodine 60 Hz type Cl motors will run hotter on 50 Hz. The motor temperature should be monitored during testing to make sure it is not overheating. 60 Hz versions of Bodine type Sl motors should not be operated on 50 Hz.
Operation of more than one motor from a single control is not normally recommended (PMDC or BLDC). However, when cost is a primary concern, a multiple motor/single control system with either permanent magnet motors and control or 3 phase motors and control may be successfully implemented. More than one AC three-phase, inverter duty motor/gearmotor may be operated with a single AC speed control (=inverter, = adjustable speed drive), as long as the sum of the motor currents does not exceed the rated output current of the control. Motor speeds should not fluctuate as long as the motors are not overloaded and the sum of the motor currents does not exceed the rated output current of the control.
Radial load is a force pushing or pulling the side of the output shaft. It is shown in the diagram (at right) as Fr. Exceeding the allowable radial load for a motor or gearmotor will cause premature wear of output shaft bearings and gearing and could cause the shaft to break. Fr may be the result of a weight on the shaft, belt tension or torque transmitted through a belt, chain, gear, or certain flexible couplings.
- The radial load is in the worst case direction, i.e. pushing or pulling the shaft sideways.
- The motor or gearmotor is delivering rated torque.
- The radial load was applied at distance "d" from the hub or mounting surface. Higher radial loads may be applied closer in on the shaft. Lower radial loads are permitted further out on the shaft.
- Radial loads for our new “SCR Rated” 24A-Z and 33A-Z gearmotors are calculated 0.5” from the drive shaft end.
Flexible couplings are often used to avoid radial load. Most flexible couplings are designed so that they do not transmit radial load, however this should be verified by the coupling manufacturer.
Axial load is a force on the output shaft into or out of the motor or gearmotor. It as shown in the diagram (at right) as Fa. Exceeding the allowable axial load for a motor or gearmotor will cause premature wear of output shaft bearings and gearing.
Bodine Electric sells both painted and unpainted products through distribution and directly to OEMs. For a given product type, the motor parts are likely the same, but paint on external surfaces will add to the overall dimensions. The paint thickness is not reflected in the dimensions on our online CAD drawings, and it could be up to .003 inches thick on each painted surface.