Engineering and Design Characteristics

Cleveland worm gear speed reducers are designed for fixed ratio applications with 90^o drive.  Compared to helical speed reducers, worm gear speed reducers offer three advantages: lower cost, more compact dimensions, and the ability to achieve deep ratios in a single unit.  Because of their differences in efficiency mechanical capacity, selection of worm gear reducers over helical gear units require analysis of the application.

These units incorporate many Cleveland Gear engineering and manufacturing features not found in other worm gear reducers.  The result is a competitively priced speed reducer that we are proud to compare with any in the world.

Cleveland Gear stocks various styles of Cleveland worm gear speed reducers.  Available units include standard Worm Top and Worm Bottom designs, with or without c-face adapters.  Ratios from 10:1 to 3600:1 and shaft center distances from 1 ¹/₃" to 8 ²⁷/₃₂" are ready for immediate shipment from our extensive inventories.  More specialized units are available on request.

Lifetime Identification

Should the unit nameplate become illegible or lost, there are permanent indicators to help identify for reorder.  The gearbox size is cast into the housing, and ratio is stamped into end of output shaft.  The gearbox model can be easily described or chosen from photographs.

Housing

Standard one-piece main housing of close-grained cast iron is heavily ribbed and finned in the bearing and gear areas.  This provides rigid support to maintain proper gear mesh alignment.  One low speed cover is blind, which strengthens the case to prevent deflection and eliminates a large joint which others must seal against leakage.  The gearbox size is cast into the housing (except on Universal units).  The housing is painted with a primer and non-toxic styrene alkyd resin finish coat and units need no further painting.  Housings for footed units have only one single fill and drain plug openings, minimizing possible leakage points.  All holes in the housing (except sizes 34 and 45) are blind drilled and tapped to eliminate avenues for oil leakage.

Worm Shaft

The integral worm and input shafts are manufactured from solid bar stock and heat treated to achieve mechanical strength, toughness and shock resistance.  The worm is precision cut, then induction hardened, and finally precision ground.  Induction hardening provides a deeper and more uniform effect for toughness and service life as compared to case hardening heat treatment processes.  Oil seal seats, bearing seats, shoulders and shaft extensions are ground.  The stepped dimensions of the oil seal and bearing seats eliminate the pressing of bearings over the oil seat, thus preventing damage and possible leakage.

Worm Shaft Material

Oil Seal

All seals are nitrite, spring loaded, single or double lip type.  Nitrite is used because of its good oil resistance, wear resistance and low temperature properties.

Worm Gear (Wheel)

On sizes 34 and 50, the wheel is cut from a solid bronze alloy.  On other units, the gear is double chill cast bronze alloy on high tensile strength cast iron central hub.  Chill casting provides desirable mechanical properties to the gear related to wear resistance and strength not obtainable with a forged gear.  The cast assembly is double locked--both rotationally and laterally--to ensure permanent joining.  The gear's alloyed bronze has 50% higher tensile strength than pure bronze to better withstand shock loads and efficiently transmit normal load with a minimum of friction loss.

    Worm Wheel Material

Shafting

All shafts through size 250 are AISI 1045 steel.  Oversized shafts help prevent deflection and the resulting misalignment at the gear mesh.  Shaft tolerances are: