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Precision Gearheads and Speed Reducers

Gearheads & Speed Reducers
We manufacture and design high-quality gears as well as complete speed-reduction systems. For build-to-print custom parts, assemblies, design, engineering and manufacturing services contact our engineering group.

Speed reducers and gear trains can be classified according to gear type as well as relative position of input and output shafts. SDP/SI offers a wide variety of standard catalog items:

  • Bu-Ord size gearheads and speed reducers
  • NEMA size planetary and spur gearheads
  • NEMA size right angle and dual output right angle planetary gearheads

We realize you may not be interested in selecting a ready-to-use speed reducer. For those of you who wish to design your own special gear train or speed reducer we offer a broad range of precision gears, types, sizes and material, available from stock.


Precision Bu-ord Size Gearheads

Precision Bu-ord Size Gearheads


SI Gearheads are designed for use in high-accuracy electromechanical systems. All gears are precision cut. The output gear and all stage pinions are made of hardened 416 Stainless Steel. All stage gears are made of aluminum bronze due to its excellent wear-in properties. Ball bearings are Stainless Steel. Housings are black-anodized aluminum alloy and are precision bored for exacting center distances. The cantilever design combined with wide bearing span results in extremely low backlash. The gearhead is attached easily and securely to the Bu-Ord frame size servomotor without modifications to the input pinion and without complicated adapters, screw threads, etc., by the versatile mounting clamp supplied. Consult the SDP/SI engineering staff for special applications.


Precision Synchro Clamps

Precision Synchro Clamps


Precision Synchro Mounting Clamps in a variety of styles, sizes and materials are available off-the-shelf. Commercial synchro mounting clamps are also offered, the difference being the material.


Precision Planetary Gearheads

Precision Planetary Gearheads


SDP/SI offers a large selection of Planetary Gearheads for a wide array of applications. A variety of styles and configurations are available as standard catalog items such as NEMA sizes, precision series, inline types, low backlash types, right-angle designs, dual-output, compact design and an economy series. If a standard catalog item doesn't meet your needs our engineering staff can provide alternative solutions through custom design and manufacturing.


Commercial Round Housing Gearheads

Precision Round Housing Gearheads


Many of the Gearheads offered are small, lightweight and a compact design. Decreased noise and smooth rotation are due to the use of high-precision gears. Sizes 12, 16, 20, 22, 27, 37, and 42 are available. See complete product specifications – download the data sheets available.


Precision Square Gearheads

Precision Square Housing Gearheads



Precision Spur Gear Type Gearheads

Precision Spur Gear Type Gearheads


Spur Gear Type Gearheads are a low-cost alternative to planetary type gearheads. Spur Gearheads are offered in a wide range of gear ratios in NEMA Sizes 23, 34 and 42. Other gear ratios and non-NEMA size mounting interfaces are available on special order.


Precision Bu-ord Type Speed Reducers

Precision Bu-ord Type Speed Reducers


The basic SI gearhead design is adapted to the double-ended Speed Reducers. The transition is accomplished by removing the motor and inserting the speed reducer input assembly using the same clamp to hold it securely and accurately in position. Either input or output end can be mounted in position since dimensions on both ends are identical. Models S9115A-T6123, S9115A-T6123A, and S9118A-T6128 single-end speed reducers use a compact reduction system whose input and output shafts are coaxially extended from the mounting end, enabling the design engineer to insert a large reduction at any location in the gear train with minimum space and backlash requirements. Consult the SDP/SI engineering staff for special applications.


Commercial Inline Shafts

Commercial Inline Shafts Speed Reducers



Commercial Parallel Shaft Speed Reducers

Commercial Parallel Shafts



Commercial and Precision Right Angle Speed Reducers

Commercial & Precision Right Angle Speed Reducers


Precision quality worm gear speed reducers for high-torque applications, input speeds up to 6000 rpm are available in multiple ratios. Speed reducers are available in other styles where special shaft diameters or extensions are required. Small to miniature sized commercial quality worm gear speed reducers are also offered in multiple ratios.