H2136173 - Hydraulic Gear Pump With 1 Inch Keyed Shaft And 1-3/4 Inch Diameter Gear

The H21 Series Hydraulic Gear Pump with Keyed Shaft from Buyers Products is a sturdy, durable bi-rotational pump that can be 2- or 4-bolt mounted in an SAE B mount. The pump is built tough of cast iron with Teflon-coated bronze thrust plates. Four internal dowels work to protect its structural integrity. Its input shaft is supported by a heavy duty bearing. Choose from a range of models with flow rates from 11.3 to 15.3 at 1000 RPM. The pumps are capable of higher pressures, taking up to 2500 or 3000 PSI. All of the models feature a 1 in. keyed shaft.

Specifications

The H21 Series Hydraulic Gear Pump from Buyers Products stands as a pinnacle of robust engineering and reliable performance within the demanding field of hydraulic power transfer. Specifically engineered for heavy-duty applications requiring consistent, high-pressure fluid delivery, this pump is characterized by its superior construction, precision components, and versatile operational capabilities. Its design focuses on delivering exceptional durability, sustained efficiency, and broad compatibility, making it an indispensable component for mobile and industrial hydraulic systems alike.

Advanced Engineering and Design Principles

At the core of the H21 Series pump's exceptional performance is a meticulously engineered design. As an external gear pump, it operates on the principle of fluid displacement between two meshing gears. One gear, typically driven by an external power source via the input shaft, drives the other (idler) gear. As the gears rotate, fluid from the inlet port is carried within the spaces between the gear teeth and the pump housing, then forced out through the outlet port as the teeth mesh, creating pressure. The H21 Series specifically features a 1-3/4 inch diameter gear with an equivalent gear width, contributing to a displacement of 3 cubic inches per revolution (CIR). This substantial displacement ensures robust fluid transfer rates, which are critical for powering various hydraulic actuators efficiently.

A key attribute of the H21 Series is its bi-rotational capability. This design flexibility allows the pump to be driven in either clockwise or counter-clockwise directions, simplifying inventory management and offering greater adaptability in system integration. This feature is particularly valuable in diverse applications where the prime mover's rotation direction may vary or where a single pump model needs to serve multiple system configurations. The choice of a 1-inch keyed shaft further reinforces this adaptability, providing a standard, highly reliable mechanical interface for torque transmission from various power take-offs (PTOs) or electric motors. The keyed shaft ensures a positive, slip-free connection, capable of handling significant torque loads without compromise.

Uncompromising Material Selection for Durability

The H21 Series pump’s structural integrity and longevity are largely attributed to its strategic material selection. The pump housing is constructed from high-grade cast iron, a material renowned for its inherent strength, rigidity, and excellent damping characteristics. In high-pressure hydraulic applications, cast iron effectively resists deformation under stress, minimizing internal leakage and maintaining critical component alignment. Its superior fatigue strength ensures that the pump can withstand continuous cyclic loading encountered in demanding operational environments. Furthermore, cast iron exhibits good vibration absorption properties, contributing to quieter operation and reduced wear on associated components.

Internal wear components are equally critical. The H21 Series incorporates Teflon-coated bronze thrust plates. These plates serve a vital function in controlling axial clearances and providing low-friction surfaces between the rotating gears and the stationary housing. Bronze, an alloy of copper and tin, is selected for its excellent bearing properties, corrosion resistance, and compatibility with various hydraulic fluids. The Teflon coating significantly enhances these properties by reducing friction, which translates directly to improved mechanical efficiency and reduced heat generation. This coating also provides superior wear resistance, extending the pump's operational life even when exposed to contaminants or marginal lubrication conditions. The combination of bronze and Teflon is a testament to the pump's design philosophy of maximizing performance and durability.

Reinforcing the internal structure and dimensional stability are four strategically placed internal dowels. These dowels are crucial for maintaining precise alignment of the pump's internal components, particularly the gear set and thrust plates, under varying pressure and temperature conditions. By preventing housing distortion and ensuring consistent internal clearances, the dowel system significantly contributes to the pump's volumetric efficiency and overall structural integrity. This engineering detail is paramount in mitigating potential internal leakage paths and maximizing the useful life of the pump in rigorous operational scenarios.

Precision Performance Specifications

The H21 Series Hydraulic Gear Pump is designed to deliver consistent and powerful hydraulic output. With a nominal displacement of 3 cubic inches per revolution, the pump generates impressive flow rates across a range of operational speeds. For instance, at a moderate 600 RPM, it delivers 7.8 GPM. Increasing the rotational speed to 1000 RPM yields a flow of 13 GPM, and at its maximum recommended speed of 2000 RPM, the pump can produce flows proportional to its displacement. Specifically, at 1200 RPM, it achieves 15.6 GPM; at 1500 RPM, 19.5 GPM; at 1800 RPM, 23.4 GPM; and at 2100 RPM, it can reach 27.3 GPM. These flow characteristics provide ample hydraulic power for rapidly actuating cylinders, driving hydraulic motors, and performing other work functions in heavy machinery.

Pressure capability is another critical performance parameter. The H21 Series is engineered to operate at maximum pressures of 2500 PSI, with certain configurations capable of reaching up to 3000 PSI. This high-pressure rating ensures that the pump can generate sufficient force to overcome substantial loads, making it suitable for demanding applications such as dump truck hoist systems, snowplow operations, and various industrial presses. The synergy between robust cast iron construction, precise gear meshing, and effective sealing mechanisms ensures that these high pressures are sustained reliably throughout the pump's operational life. The maximum rotational speed of 2000 RPM further underscores its capability for high-performance applications, maintaining mechanical and volumetric efficiency even under continuous duty cycles.

Advanced Shaft and Bearing System

The input shaft, a critical interface between the prime mover and the pump, is a 1-inch keyed shaft. This configuration is standard across the H21 Series, offering broad compatibility and ease of integration into existing systems. The keyed design facilitates direct, positive torque transfer, preventing slippage and ensuring maximum power delivery from the drive source to the pump's internal gears. The shaft material is carefully selected and often heat-treated to withstand torsional stresses, bending moments, and wear from coupling components.

Supporting this robust input shaft is a heavy-duty bearing system. Bearings are pivotal in maintaining the concentricity of the shaft, absorbing radial and axial loads, and minimizing friction. The use of a "heavy-duty" bearing implies a design choice that prioritizes longevity and performance under strenuous conditions. This typically involves bearings with higher load capacities, improved lubrication pathways, and often precision-machined races to ensure smooth, efficient operation. A superior bearing system significantly contributes to the pump's overall reliability, reducing wear and tear on the shaft and gears, and extending the service interval of the unit.

Versatile Mounting and Porting Configurations

The H21 Series offers exceptional versatility in system integration through its standardized mounting and porting options. It features an SAE B 2- or 4-bolt mount, providing a universally accepted interface for direct coupling to various power take-offs (PTOs), transmissions, or auxiliary drive systems. The ability to utilize either a 2-bolt or 4-bolt pattern enhances its adaptability to a wider array of equipment without requiring costly adapters or custom mounting solutions. Furthermore, the pump is designed for both direct and remote mounting, with an integral bracket for flexible installation within a hydraulic circuit. The 4.00-inch pilot diameter ensures precise alignment with the prime mover, which is crucial for preventing premature bearing and shaft wear due caused by misalignment.

For fluid connection, the H21 Series provides flexible porting options. The primary inlet (suction) port and outlet (pressure) port sizes are 1 1/4 NPT. NPT (National Pipe Taper) threads are a common standard, facilitating easy connection with readily available hydraulic fittings and hoses. The generous sizing of these ports is critical for minimizing pressure drop and preventing cavitation on the suction side, which can severely damage a pump. Additionally, the pump features a 1 NPT rear port and side port options, allowing for diverse plumbing configurations to suit specific application layouts and spatial constraints. This multi-port flexibility simplifies hydraulic system design and installation.

Broad Spectrum of Applications

The H21 Series Hydraulic Gear Pump is engineered for a diverse range of demanding applications where reliability and performance are paramount. In mobile hydraulics, it is an ideal choice for municipal and construction vehicles such as dump trucks, refuse compactors, snowplows, salt spreaders, and utility trucks. Its robust construction and high-pressure capabilities make it suitable for powering hydraulic cylinders, motors, and other actuators that perform heavy lifting, pushing, or pulling tasks. Agricultural machinery, including tractors and harvesters, can also benefit from its consistent fluid delivery for implements and attachments.

Within industrial settings, the H21 Series finds utility in various power units, material handling equipment, presses, and specialized machinery. Its ability to operate reliably under continuous duty cycles and challenging environmental conditions makes it a preferred component in manufacturing plants, mining operations, and marine applications. The bi-rotational feature further expands its applicability, allowing for seamless integration into systems that require directional flexibility without complex valve arrangements or multiple pump configurations.

Installation, Operation, and Maintenance Best Practices

To ensure optimal performance and longevity of the H21 Series Hydraulic Gear Pump, adherence to proper installation, operation, and maintenance procedures is essential. During installation, meticulous attention must be paid to alignment between the pump shaft and the prime mover to prevent excessive radial or axial loads on the heavy-duty bearing. The use of clean, high-quality hydraulic fluid, meeting or exceeding ISO cleanliness standards, is paramount. Contaminants are the leading cause of hydraulic pump failure, making robust filtration (both suction and pressure line filters) an indispensable part of any hydraulic system utilizing this pump.

Before initial startup, proper priming of the pump is critical to ensure that fluid is drawn into the pump body and air is expelled, preventing dry running and subsequent damage. During operation, routine monitoring of system pressure, temperature, and noise levels can provide early indicators of potential issues. Periodic preventative maintenance, including fluid analysis, filter replacement, and inspection of seals and fittings, will significantly extend the pump's service life and prevent costly downtime. The H21 Series is designed for straightforward maintenance, facilitating ease of service for hydraulic technicians.

Conclusion

The H21 Series Hydraulic Gear Pump with its 1-inch keyed shaft and 1-3/4 inch diameter gear from Buyers Products represents an exemplary solution for high-performance hydraulic applications. Its deliberate engineering choices, including a cast iron body, Teflon-coated bronze thrust plates, and a heavy-duty bearing, collectively ensure superior durability, efficiency, and reliability. Offering versatile bi-rotational operation, broad flow rate capabilities from 7.8 GPM at 600 RPM up to 27.3 GPM at 2100 RPM, and robust pressure handling up to 2500 PSI (and in some models, 3000 PSI), it meets the rigorous demands of mobile and industrial hydraulic systems. The standardized SAE B mounting and flexible NPT porting further enhance its ease of integration. For engineers and operators seeking a robust, long-lasting, and high-performing hydraulic pump that delivers consistent power in the most challenging environments, the H21 Series is an investment in unwavering operational excellence.