Original Fan Cooled Gear Drive

This Drive may be used as a Double Engine Drive or as a Combination Drive using a horizontal electric motor and engine. When used as a Combination Drive, over-running clutches should be provided for disengaging the idle driver. When used as a Dual Drive with the two input loads equal, the transmission capacity is 150% of the standard rating of the G40 through G200A only. Dual Drives are not available in the Model F30. Contact the factory for the maximum rating of the G250 through G400.


The Randolph Right Angle Pump Drive may be used with straight belt, either V or flat; however, a pulley designed to centre the pull of the belt over the outside horizontal bearings must be used or excessive wear on the bearings could result.

OTHER SPECIAL DRIVES Randolph Manufacturing Company has manufactured many specialised drives, and will be pleased to receive your enquiries regarding drive applications not covered in this catalogue. Ratios not shown in Table 4 and Table 6 will be quoted on request, if available. Please contact the factory if there are any specific specifications that are not covered in this catalogue. Randolph Manufacturing Company will make changes or additions where possible to accommodate special specifications.

FAN COOLED GEAR DRIVES NOTE: All Models with the suffix “R” have no fan; therefore, the M80R, M100R, G100R and larger must be water cooled. Our air cooled heat exchanger was designed to meet a need in areas where cooling water and ambient temperatures created a problem when cooling coils were only the only way to cool the oil in the gear drive. The Models F30 through G200A, with fan cooling only, should require no other means of cooling. The Models M100, M200 and G250 through F1500 have cooling coils included and must be connected for any extended use or high ambient conditions. All propeller pump drives require no water cooling. Oil temperatures of 93°C (200°F) are not dangerous. Best temperatures would range between 57°C (135°F) and 82°C (180°F).

GEAR DRIVE CONSTRUCTION High tensile strength castings are used throughout for rigidity. An outstanding feature of Randolph Gear Drives is anti-friction ball or taper bearings, which are engineered for long life and rugged service. There is a large oil level sight gauge glass on all drives except the Model F30. The air cooled heat exchanger, for control of oil temperature rise, eliminates clogged cooling coils, expensive cooling water hook-ups, and the use of undesirable types of cooling water. Alloy steel spiral bevel gears and pinions are case hardened and lapped in pairs to ensure perfect contact and long life. Positive type non-reverse available on all models. Pressure type lubrication systems on all drives, except the Model F30. (Lubrication systems are available for very low speed applications upon request). The permissible loading varies with the speed. In borderline cases, a maximum of 10% overloading is permitted before the warranty is voided. This overloading condition should be used with the knowledge that a corresponding reduction at 20% to 30% in bearing life may be expected.

RANDOLPH GEAR DRIVE EFFICIENCIES Randolph Manufacturing Company recommends a design value of 96% efficiency in all applications. The actual efficiency, will depend on operation loads, speeds, temperatures, and other parameters. The 96% value can be taken as a minimum value throughout the life of the unit. If unusual conditions exist, consult the factory for your specific application.