Danfoss planter S45 series open pump
Danfoss S45 Series Open Circuit Pump for Seeders
1. Overview
The Danfoss S45 Series Open Circuit Pump is a high-performance axial piston variable pump specifically engineered for seeding machinery and other agricultural equipment. As a core component of the hydraulic system, it efficiently converts the mechanical energy of the engine into hydraulic energy, providing reliable power transmission for the key operations of seeders, such as sowing depth adjustment, seed metering, and row spacing control. The S45 Series is designed to exceed the performance requirements of the mobile machinery market, with optimized performance, compact size, and cost-effectiveness, making it an ideal choice for modern high-efficiency seeding equipment .
2. Key Design Features
- Single Servo Piston Design: Equipped with a cradle-type swashplate mounted on polymer-coated radial plain bearings. The bias spring and internal force act to increase the swashplate angle, while the servo piston is responsible for reducing it, enabling precise control of pump displacement .
- High-Efficiency Oil Distribution: The valve plate in contact with the cylinder block adopts a bimetallic structure, which effectively improves volumetric efficiency and reduces operating noise. Computer-modeled optimized oil suction pipelines maximize the pump’s operating speed .
- Robust Construction: Features heavy-duty tapered roller bearings for the main shaft support, extending the service life of the pump. The integrated rigid housing design reduces noise and leakage, while lip-type fluororubber seals at the shaft end prevent oil leakage .
- Multiple Control Options: Offers a variety of control modes to adapt to different seeding working conditions, including load sensing control, pressure compensation control, electrical proportional pressure control, remote pressure control, and on/off electrical control via PC/LS .
- Compact and Versatile Installation: The compact design minimizes the installation space required. It provides multiple options for mounting flanges, input shafts, and oil ports, and supports through-shaft drive configuration for multi-circuit systems, facilitating integration with various seeder models .
3. Technical Specifications
| Parameter | Value Range |
|---|---|
| Displacement | 25 cm³/rev – 147 cm³/rev (1.53 in³/rev – 8.97 in³/rev); Rated displacement for S45 F: 74 cm³/rev – 90 cm³/rev (4.52 in³/rev – 5.49 in³/rev) |
| Maximum Pressure | 400 bar (5800 psi) |
| Continuous Pressure | 260 bar – 310 bar (3770 psi – 4495 psi) |
| Maximum Speed | 3600 rpm |
| Control Options | Load Sensing, Pressure Compensation, Electrical Proportional Control (Pressure), Remote Pressure, On/Off Electrical Control via PC/PC/LS |
| Shaft Seal | Lip-type Fluororubber Seal |
| Shaft Bearing | Tapered Roller Bearing |
4. Application Advantages in Seeders
- Energy Efficiency: The variable displacement design adjusts output flow according to the actual load demand of the seeder. When the seeding operation load is low, the pump reduces displacement to save engine power, which helps to use smaller-sized engines and meet strict emission standards .
- Precise Operation Control: The integrated control system shortens the response time of the hydraulic system, ensuring accurate control of seeding depth and seed metering volume. The load sensing control maintains a stable pressure difference, making the seeding operation more uniform and improving seeding quality .
- High Reliability: Undergoes rigorous laboratory and field verification, with strict quality control in production. The design with fewer parts and gasketless connections reduces failure points, and the high-strength bearings can withstand large external loads, adapting to the harsh working environment of agricultural fields .
- Easy Maintenance: Equipped with integrated test oil ports for convenient monitoring of pump operation status. The simple structure and standardized parts facilitate maintenance and replacement, reducing downtime of seeding machinery .
- System Compatibility: Works seamlessly with Danfoss PVG series load-sensing directional control valves and RDM piston motors, forming an efficient hydraulic system. It can also be integrated with angle sensors to realize real-time monitoring of swashplate angle and displacement information, supporting intelligent seeding operation management .
5. System Integration
In seeder hydraulic systems, the S45 Series Open Circuit Pump draws oil directly from the fuel tank through the suction line, with a filter screen on the suction line to prevent large particle contamination. The pump supplies pressure oil to the PVG series directional control valves, which control the flow direction of hydraulic oil to hydraulic cylinders and motors for seeding mechanism adjustment. The return oil from the control valve is cooled by a heat exchanger and filtered by a return filter before returning to the tank. The load sensing pressure signal (LS signal) is directly connected to the pump displacement control system, which adjusts the swashplate angle by comparing the pump outlet pressure and the load sensing circuit pressure, thereby precisely controlling the output flow .
6. Quality and Reliability Assurance
The Danfoss S45 Series Open Circuit Pump is designed and manufactured in accordance with strict international standards. It adopts Quality Function Deployment (QFD) and Design for Manufacturing (DFM) technologies to optimize product quality and production efficiency. The product has a long service life and is supported by Danfoss’s global after-sales service network, providing reliable technical support and spare parts supply for agricultural users .
