OA SERIES GEAR PUMPS

Our OA Series Gear Pumps integrate precision-engineered external spur gears matching strict ISO tolerances. The internal thrust plates feature hydrostatically balanced floating bushings that automatically compensate for axial clearances during load cycles. This specialized design reduces fluid blow-by between gear teeth faces, maintaining volumetric efficiency above 90% across long service periods.

The distinction lies in the mechanical interface specified by global commercial truck chassis builders. The DIN Configuration utilizes a standardized 4-bolt rectangular mounting flange paired with an 8x32x36 splined drive shaft. Conversely, the UNI Configuration incorporates a classic 3-bolt triangular pattern combined with a specialized 6x21x25 splined input shaft, ensuring accurate replacement for varied PTO types.

This series is widely recommended for medium-to-heavy mobile vehicle setups. Key implementations include semi-trailer tipping chassis, rigid dump truck tippers, light-to-medium hydraulic truck cranes, refuse compaction vehicles, recovery tow trucks, and public utility service equipment requiring reliable PTO-driven oil flow.

The structural parameters of the Hayneks OA Series accommodate extensive capacity requirements. Depending on the internal gear width, displacements span from 17 cc/rev up to 82 cc/rev or 100 cc/rev. Continuous working pressure envelopes operate safely up to 200-290 bar, securely absorbing sudden pressure spikes during peak tipping loads.

External gear pumps feature dedicated suction and pressure ports determined by gear rotation; running a pump backward will pressurize the shaft seal, causing immediate blowout failure. Hayneks supplies specified Left-Hand (Counter-Clockwise) and Right-Hand (Clockwise) models, alongside dual-rotation variants that can be calibrated by reversing the internal rear cover configuration.

Our gear pump cores feature heavy-duty, anti-friction DU Teflon-lined bushings that absorb radial loads from high-pressure gear engagement. The front drive shaft is secured by premium reinforced Nitrile (NBR) or optional high-temperature Viton (FKM) shaft lips, backed by secondary shaft wipers to prevent environmental dust ingress and cross-fluid contamination.

Angular misalignment between the gear pump shaft and the truck's internal PTO drive splines generates intense structural radial loads. Over time, this mechanical fatigue scores internal thrust plates, ruins front bearings, and compromises the main shaft seal. Every Hayneks unit matches strict geometric machining tolerances to ensure perfectly concentric flange mating.

Micro-abrasive particulate debris suspended in hydraulic fluid acts as an industrial grinding agent, scratching the pump’s internal aluminum track walls and decreasing pressure performance. Fleet operators must maintain a strict system cleanliness level matching ISO 4406 20/18/15, backed by high-capacity suction strainers and 25-micron return filtration blocks.

Absolutely. Every pump housing matches international dimensional standardizations for commercial transport hydraulics. They function as high-performance, cost-effective 1:1 mechanical drop-in replacements for standard components utilized by major global body builders and European truck equipment manufacturers.

To avoid severe mechanical breakdown, fleet maintenance teams should check mounting bolt torques and port fitting sealing boundaries every 250 operating hours. Additionally, replacing hydraulic oil seasonally prevents fluid thinning at high running temperatures, safeguarding the oil film boundary inside gear meshes.