Excavator 705-51 705-95 705-58 Series 705-51-20440 Hydraulic Oil Gear Pump D575A-2

1. Technical parameters
Since this model is a part number, its specific parameters are entirely dependent on the host equipment to which it belongs. The following parameters are estimates based on the main hydraulic pumps of Caterpillar medium excavators or large loaders (such as Cat 336D, 340D or 966K, etc.) that are commonly used:Type: Variable axial piston pump
Displacement: Approximately 50-60 cm³/rev (displacement per revolution)
Rated working pressure: approximately 34.5 MPa (5000 psi)
Peak pressure: approximately 38 MPa (5500 psi) or above
Drive mode: Directly connected to the engine, through spline transmission
Control mode: Load sensitive control, power limit control (working in coordination with the main controller ECM)
Recommended viscosity: ISO VG 46 or hydraulic oil in compliance with Cat HYDO standards
Operating temperature range: -40°C to 100°C
Note: The above parameters are for reference only. Please be sure to obtain the most accurate specific equipment parameters through the equipment nameplate, maintenance manual or by contacting an official Caterpillar dealer.

2. Product features and advantages
As a core component of Caterpillar’s original hydraulic system, the design of this pump embodies the following features and advantages:

High power density: Achieving large flow and high pressure output within a compact structure, the main equipment is endowed with powerful digging force and lifting force.
Outstanding efficiency: With precise plunger and distribution plate design, it features high volumetric efficiency and mechanical efficiency, effectively reducing fuel consumption and heat generation.
Intelligent control: Integrated with an advanced load sensing system, it can automatically adjust the flow and pressure according to the actual working conditions, achieving “on-demand fuel supply” and avoiding energy waste.
Outstanding reliability & long service life: Utilizing high-strength materials and world-class manufacturing processes (such as high-quality bearings and specially treated friction pairs), it features excellent wear resistance and impact resistance, ensuring a long service life.
Excellent compatibility: Specifically designed for Caterpillar’s hydraulic systems, it perfectly matches and works in coordination with the electronic control module (ECM), pilot system and other hydraulic components of the equipment.
Maintenance convenience: As an original factory part, it comes with a complete maintenance Kit (Seal Kit), technical support and diagnostic tools, facilitating later maintenance and refurbishment.

3. Usage functions
In the hydraulic system, the core function of this pump is:
Convert the mechanical energy output by the engine into hydraulic energy to provide a continuous and stable high-pressure oil source for the entire hydraulic system. It is the “heart” of the hydraulic system, driving the hydraulic cylinder (to perform actions such as digging, lifting, and tilting) and the hydraulic motor (to drive functions such as walking and rotating).

4. Product detail description
Structure: A typical swashplate axial piston pump. The main components include:
Shell: High-strength cast iron, providing solid support and integrated oil passage.
Cylinder block: It contains multiple precision plunger holes.
Plunger slipper assembly: Converts rotational motion into reciprocating motion and is the core power-doing component.
Swash plate: With variable Angle, it is used to change the plunger stroke and thereby regulate the pump’s displacement.
Distribution plate: Precisely ground, used for the distribution and isolation of high and low pressure oil.
Control piston: In response to the pilot oil pressure, it pushes the swash plate to change its Angle.
Servo valve/regulator: The brain, controls the movement of the control piston based on the load feedback signal.

5. Applicable machines and scenarios
Applicable machines: Mainly used for medium and large-sized construction machinery equipment of Caterpillar.
Hydraulic excavators: such as models 336D, 336F, 340D, 340F, etc.
Wheel loaders: such as models 966K, 972K, etc.
It may also be applied to some large bulldozers, material handling equipment, etc.
Application scenarios: Suitable for various heavy-load and continuous working conditions.
Mining
Large-scale earthwork and stonework projects
Infrastructure construction (road building, bridge construction, dam building)
Quarry
Port logistics

6. Relevant models