ABB HMB/AHMA Hydraulic Charging Gear

Replacement hydraulic charging gear for ABB HMB and AHMA oil circuit breakers. Bevel gear machined to OEM tooth count and dimensions — reverse-engineered from a sample when the OEM part is discontinued. Material certification available on request.

OEMABB

Part typeGear

EquipmentABB HMB, AHMA oil circuit breakers

DocumentationMaterial certification on request

AvailabilityBuilt to order / short lead times

Overview

The ABB HMB and AHMA hydraulic circuit breakers use a bevel gear in the spring-charging mechanism. When the gear wears or breaks, the spring can no longer charge and the breaker will not operate. Southern Switch machines a direct replacement to OEM tooth count and dimensional specification — reverse-engineered from a sample. Lead times are short; material certification is available on request.

Why this part fails

The charging gear is a high-cycle component. Each close-open operation drives the charging motor, which loads the gear teeth repeatedly under spring preload. Plastic or composite OEM gears are particularly susceptible to tooth shear in cold weather or after years of compressed spring cycles. A broken gear leaves the breaker unable to charge — typically discovered during a routine trip test or after a fault clears and the breaker fails to reclose.

Made to your sample or print

When a part is obsolete or unavailable, we reverse-engineer it from a sample, a drawing, or a model number and machine a precise replacement.

Stock, lead time & reverse engineering

Common items are produced on short lead times; discontinued or hard-to-find parts are reverse-engineered from a sample, a drawing, or a model number. Based in Palm Harbor, FL, Southern Switch & Contacts manufactures and ships replacement parts to utilities nationwide, and has served the industry since 1982.