Various gear pumps for construction machinery

4 week ago

4 0 

4 year

Product details

Various Gear Pumps for Construction Machinery: A Comprehensive Overview

I. Introduction to Gear Pumps in Construction Machinery

Gear pumps, as a type of positive displacement pump, play a crucial role in the hydraulic systems of construction machinery. They are known for their simple structure, compact size, and reliable performance, making them widely used in various construction equipment such as excavators, loaders, bulldozers, and cranes. Gear pumps work by using the meshing of gears to create a vacuum at the inlet, drawing in fluid, and then forcing it out through the outlet under pressure.

II. Types of Gear Pumps for Construction Machinery

1. External Gear Pumps

• Structure: Consist of two external gears that mesh with each other. One gear is driven by a power source, and the other gear rotates in the opposite direction due to the meshing action. The fluid is trapped between the gear teeth and the pump casing and is carried from the inlet to the outlet.

• Applications: Commonly used in the hydraulic systems of small to medium-sized construction machinery, such as mini-excavators and small loaders, for tasks like steering, lifting, and tilting operations. They are suitable for applications with relatively low flow rates and moderate pressures.

• Advantages: Simple design, easy to manufacture and maintain, and cost-effective. They can handle a wide range of fluids, including those with moderate viscosity.

2. Internal Gear Pumps

• Structure: Feature an internal gear (a gear with teeth on the inside) and an external gear (a gear with teeth on the outside). The internal gear is usually driven, and the external gear rotates inside it. The fluid is trapped in the spaces between the gear teeth and the pump casing and is transported from the inlet to the outlet.

• Applications: Often used in construction machinery that requires higher flow rates and pressures, such as large excavators and cranes. They are suitable for applications where a smooth and continuous flow of fluid is required, such as in hydraulic cylinders for lifting heavy loads.

• Advantages: Provide a more uniform flow compared to external gear pumps, reducing pulsation and vibration. They can handle higher pressures and are more efficient at higher speeds.

3. Lobe Pumps (a variant of gear pumps)

• Structure: Similar to gear pumps but use lobes instead of gears. The lobes are designed in a way that they do not touch each other during rotation, reducing wear and tear. The fluid is trapped between the lobes and the pump casing and is moved from the inlet to the outlet.

• Applications: Used in construction machinery where high-precision fluid delivery is required, such as in concrete pumps for precise control of concrete flow during construction projects. They are also suitable for handling abrasive fluids.

• Advantages: Offer high volumetric efficiency, low noise levels, and long service life. They can handle fluids with high solid content without significant damage to the pump components.

III. Key Features and Specifications of Gear Pumps for Construction Machinery

1. Flow Rate: The amount of fluid that the pump can deliver per unit of time, usually measured in liters per minute (L/min) or gallons per minute (GPM). Construction machinery requires different flow rates depending on the application. For example, a small excavator may require a flow rate of 20 - 50 L/min for its steering system, while a large crane may need a flow rate of several hundred liters per minute for its lifting operations.

2. Pressure Rating: The maximum pressure that the pump can generate, typically measured in bars or pounds per square inch (psi). Construction machinery often operates under high-pressure conditions. For instance, hydraulic systems in excavators may require pressures up to 350 bar (5000 psi) to perform heavy-duty tasks.

3. Viscosity Range: The range of fluid viscosities that the pump can handle effectively. Construction machinery may use different types of hydraulic fluids with varying viscosities depending on the operating temperature and application. Gear pumps are generally capable of handling fluids with viscosities ranging from low (such as water-based fluids) to high (such as thick greases).

4. Material Construction: The materials used to manufacture the pump components, such as the gears, casing, and seals. In construction machinery, where the pumps are exposed to harsh operating conditions, including dirt, dust, and high temperatures, durable materials like cast iron, steel, and high-performance plastics are commonly used to ensure long service life and reliable performance.

IV. Selection Considerations for Gear Pumps in Construction Machinery

1. Application Requirements: Determine the specific flow rate, pressure, and fluid type required for the construction machinery application. For example, if the equipment is used for precise lifting operations, a pump with high pressure rating and uniform flow is preferred.

2. Compatibility: Ensure that the gear pump is compatible with the existing hydraulic system of the construction machinery, including the fluid type, temperature range, and connection sizes.

3. Reliability and Durability: Consider the reputation of the pump manufacturer and the quality of the materials used. Construction machinery often operates in demanding environments, so a reliable and durable pump is essential to minimize downtime and maintenance costs.

4. Cost-Effectiveness: Evaluate the initial cost of the pump as well as the long-term operating costs, including maintenance and energy consumption. While a high-quality pump may have a higher initial cost, it can offer better performance and lower overall costs over its service life.

V. Maintenance and Troubleshooting of Gear Pumps in Construction Machinery

1. Regular Maintenance

• Fluid Inspection: Check the hydraulic fluid regularly for contamination, such as dirt, water, or metal particles. Contaminated fluid can cause wear and tear on the pump components and reduce performance. Replace the fluid as recommended by the manufacturer.

• Seal Inspection: Inspect the seals for leaks. Leaking seals can lead to fluid loss and contamination of the surrounding environment. Replace any damaged seals promptly.

• Gear Inspection: Check the gears for signs of wear, such as pitting, scoring, or excessive clearance. Worn gears can cause noise, vibration, and reduced flow rate. Replace the gears if necessary.

2. Common Troubleshooting Issues

• Low Flow Rate: This can be caused by a clogged inlet filter, worn gears, or a low fluid level. Check and clean the inlet filter, inspect the gears for wear, and ensure that the fluid level is sufficient.

• High Noise Level: Excessive noise may be due to worn gears, misaligned components, or cavitation. Inspect the gears for wear, check the alignment of the pump components, and ensure that the fluid viscosity is appropriate to prevent cavitation.

• Leakage: Leaks can occur at the seals, connections, or pump casing. Check the seals for damage, tighten the connections, and inspect the pump casing for cracks or defects.