L2F12R2P4 Liyuan Hydraulic Motor 12cc 32MPa Bent Axis

Product Overview

The L2F12R2P4 is a bent-axis fixed displacement axial piston motor built on the Liyuan L2F series platform, in the 12 cc displacement size. The motor features a bent-axis design with fixed displacement configuration, specifically engineered for hydrostatic drives in both open and closed circuits. It offers a nominal pressure of 32 MPa, an operating temperature range of 30–90°C, a displacement of 12 mL/r, and flange mounting.

The L2F series is a representative product line of Liyuan Hydraulic (Shandong AVIC Liyuan) fixed displacement piston pumps/motors. The cylinder block and port plate utilize spherical porting that self-centers during rotation, minimizing circumferential velocity and maximizing efficiency. The drive shaft is designed to withstand radial loads, and the motor operates with low noise, making it suitable for hydraulic systems in construction machinery, mining equipment, cranes, and petroleum machinery.

The model code L2F12R2P4 decodes as follows: L2F designates the Liyuan fixed displacement piston pump/motor series, 12 is the displacement size (12 mL/r), R2 is the rotation direction and structural code (right-hand rotation), and P4 is the mounting flange and port configuration code. The motor’s fixed displacement design eliminates the need for complex variable adjustment mechanisms, reducing system integration complexity and minimizing maintenance risks associated with adjustment mechanism wear or failure.

Technical Specifications 

• Model: L2F12R2P4

• Series: Liyuan L2F fixed displacement piston pump/motor series

• Motor Type: Bent-axis axial piston fixed displacement motor

• Design Feature: Bent-axis configuration, spherical porting, fixed displacement

• Displacement: 12 mL/r (12 cc/rev)

• Nominal Pressure: 32 MPa (320 bar / 4,641 PSI)

• Operating Temperature: 30–90°C

• Material: Cast iron

• Mounting: Flange mounting

• Hydraulic Fluid: Hydraulic oil

• Rotation: Right-hand (R)

• Circuit: Open circuit / Closed circuit

• Flow Characteristic: Output speed proportional to input flow, inversely proportional to displacement

Key Technical Advantages

1. Spherical Porting with Self-Centering Design for High Efficiency

The L2F12R2P4 employs a spherical porting design between the cylinder block and port plate, which self-centers during rotation, minimizing circumferential velocity and effectively reducing friction losses and leakage in the porting pair. Compared to flat port plate designs, spherical porting provides superior sealing performance and thermal stability under high-speed and high-pressure conditions, maintaining high volumetric and mechanical efficiency at the nominal pressure of 32 MPa.

2. Drive Shaft Radial Load Capacity

The motor’s drive shaft is specially designed to withstand radial loads, making it suitable for applications with direct belt, gear, or sprocket drives without additional bearing support structures, simplifying system integration. This characteristic offers significant advantages in travel drives and winch drives for construction and mining machinery.

3. Fixed Displacement Simplicity with Low Maintenance Risk

The L2F12R2P4 features a fixed displacement design with constant displacement, simple control logic, and stable operating characteristics. The absence of complex variable adjustment mechanisms reduces system integration complexity and minimizes maintenance risks associated with adjustment mechanism wear or failure. It delivers stable power output under continuous duty conditions, suitable for open and closed hydraulic systems requiring high flow stability.

4. Low Noise Operation with Wide Temperature Adaptability

The motor is designed and manufactured with a focus on reducing operating noise. The spherical porting structure and precision-machined piston pairs effectively reduce pressure pulsation and mechanical vibration. The operating temperature range of 30–90°C enables stable operation across diverse environmental conditions, suitable for outdoor construction machinery and industrial hydraulic systems under continuous duty requirements.

Application Areas

• Construction Machinery: Mini excavator swing drives, skid steer loader travel drives, road maintenance equipment

• Mining Equipment: Coal mine drills, underground transport equipment, drill power heads

• Crane Machinery: Compact winch mechanisms, swing mechanisms

• Petroleum Machinery: Drilling equipment auxiliary drives

• Industrial Hydraulics: Hydraulic power units, hydrostatic transmission systems, test bench drives

Expert Maintenance Tips

1. Hydraulic Fluid Cleanliness Control: The L2F series motor features precision clearances in the porting and piston pairs. Maintain hydraulic fluid cleanliness at NAS Level 9 or better. Replace hydraulic fluid regularly (every 1,000–3,000 operating hours or six months) to prevent contaminant particles from accelerating port plate wear.

2. Shaft Alignment Requirements: During flange mounting, ensure the coaxiality deviation between the motor shaft and drive-end coupling does not exceed 0.05 mm. Although the drive shaft can withstand radial loads, excessive radial forces will accelerate bearing and shaft seal wear.

3. Initial Startup Preparation: Fill the motor housing with clean hydraulic fluid during initial installation to prevent dry friction on piston and porting pairs during startup. The drain port must be connected separately to the reservoir with back pressure not exceeding 0.5 MPa.

4. Temperature Monitoring: Maintain case temperature below 80°C during operation. If temperature rises abnormally, check for system pressure overload or sudden increases in case drain leakage.

5. Periodic Efficiency Testing: Test the motor’s volumetric efficiency every 1,000 operating hours. When overall efficiency drops below 72%, the motor must be taken offline for repair. A leakage increase exceeding 50% of normal value requires inspection of piston pair and port plate wear.