Dodge Para-Flex Coupling Selection (PH131)

A customer was changing the existing motor to one from a different manufacturer in a pump drive arrangement and he needed a Dodge Para-Flex coupling to suit the new setup. The Dodge Para-Flex high speed coupling utilizes a rubber tyre type element as the power transmission link between driving and driven shafts. This permits a little flexibility during operation as well as offering good vibration damping characteristics and crucially it allows combined misalignment between shafts. Specifically; 1° angular misalignment, 1/16” parallel offset and 3/16” total maximum axial displacement.

The PH131 Para-Flex high speed coupling consists of: -
• Flexible rubber element – 011231.
• Disc assembly – 011311.
• Flange – 010607.
To ensure the coupling fits the new motor, attention must be given to the shaft diameters, which need to fit precisely into the coupling disc and flange using a taper lock bush in this example.
If the taper lock fitting option is selected for both coupling halves, use the suffix TL for bushing ref 2517 to suit this specific coupling. The bush is available in over thirty different bore sizes to suit shaft diameters ranging from 1/2” to 2 11/16” and each bush has its own unique reference number. See table below or speak to MROSupply service representatives or coupling manufacturer’s technical staff.

This coupling is the high-speed variant and can operate at rotational speeds up to 3750 rpm. Its rated torque transmission value is 5985 in-lbs (676 Nm). It has a mass of 60lbs (27 kg) and an inertia value of 8.87 lb-ft2 (0.37 kg m2).
If the new drive arrangement is transmitting more power and torque or the speed or service factor has changed, then the given coupling may become overloaded and result in a short service life. To ensure the coupling is still capable of transmitting the drive safely and reliably, a calculation and coupling selection check will need to be performed by a mechanical engineer or a coupling manufacturer’s technical representative.
During coupling installation always follow the manufacturer’s recommended assembly procedure to ensure safety and reliability of the coupling in service.