Product Overview
The 45M185A11C20 is a 45M-frame high-speed, high-pressure fixed-displacement vane motor from the Vickers (Eaton) M Series, featuring a geometric displacement of 193.2 cm³/rev (11.79 in³/rev) and a torque rating of 185 lb-in per 100 psi. The M Series spans 25M, 35M, 45M, and 50M standard-bearing models alongside 26M, 36M, 46M, and 51M heavy-duty bearing variants, all sharing a common design platform and mounting interface standard.
At the heart of the M Series is the drive cartridge — a self-contained assembly comprising a cam ring, rotor, ten vanes, and two pressure plates, bolted together as a single serviceable unit. This architecture enables cartridge replacement in approximately 10 minutes, typically without removing the motor from the machine or disconnecting hydraulic lines. Shaft rotation is reversed simply by reversing flow direction through the motor ports, and with proper valve protection, the motor can withstand rapid cycle reversing or stall conditions without damage.
As a direct interchange unit for the Vickers M Series, the 45M185A11C20 is dimensionally compatible with OEM Eaton/Vickers motors in mounting flange (SAE 2-bolt), shaft extension (Type 11 splined), and port connection (SAE 4-bolt flange). Every unit undergoes 100% simulated operating condition testing prior to shipment, verifying displacement accuracy, pressure integrity, and torque output consistency.
Technical Specifications
Model: 45M185A11C20
Brand Series: Vickers (Eaton) M Series 45M
Motor Type: High-speed high-pressure fixed-displacement vane motor
Displacement: 193.2 cm³/rev (11.79 in³/rev)
Torque Rating: 185 lb-in/100 psi (20.9 Nm/6.9 bar)
Rated Output Torque: 20.9 Nm (185 lbf-in)
Continuous Pressure: 155 bar (2250 psi)
Intermittent Pressure: 172 bar (2500 psi)
Maximum Continuous Speed: 2600 r/min @ 155 bar
Maximum Intermittent Speed: 3000 r/min @ 172 bar
Minimum Speed: Approximately 100 r/min
Rated Flow @ 1200 r/min: 232.0 L/min (61.3 USgpm)
Mounting Flange: SAE 2-bolt
Shaft Extension: Type 11 splined
Port Connection: SAE 4-bolt flange
Cover Position: Type C (cover port in line with body port)
Design Number: 20
Weight: Approximately 39 kg (85 lb)
Sources: Vickers M Series official technical data.
Key Technical Advantages
1. Replaceable Drive Cartridge — Core Overhaul in 10 Minutes
The M Series drive cartridge — comprising the cam ring, rotor, ten vanes, and two pressure plates — is bolted together as a self-contained module. Major overhauls require only removing the end cover, extracting the old cartridge, and installing the replacement. The motor typically does not need to be removed from the machine, nor do hydraulic lines need to be disconnected. This design reduces conventional hydraulic motor overhaul downtime from hours to approximately 10 minutes, delivering substantial operational value for continuous-production environments.
2. Hydraulically Balanced Radial Design — Long Life at High Pressure
The vanes and rotor in M Series motors are hydraulically balanced in the radial direction, with pressure forces on opposing sides of the rotor cancelling each other out. The bearings therefore carry pure torsional load rather than combined torsional and radial hydraulic loads. This balanced design enables sustained operation at 172 bar peak pressure while maintaining low noise levels. Vickers documentation explicitly states that M Series motors “start out with high efficiencies and operate at those levels throughout the life of the motor”.
3. Heavy-Duty Bearing Option — For Indirect Drive Applications
Standard 45M models are equipped with standard bearings, suitable for direct coupling drives. For applications involving gear, belt, or pulley drives — where significant radial loads are imposed on the shaft — the heavy-duty bearing variants (26M, 36M, 46M, 51M) offer substantially increased radial load capacity. This allows engineers to select the appropriate bearing configuration for the specific drive train.
4. Wide Speed Range and Rapid Reversal — Engineering Flexibility
M Series motors operate from as low as 100 r/min to 3000 r/min at maximum pressure, with higher speeds available (up to 4000 r/min) as system pressure decreases. Reversing is accomplished by simply changing flow direction through the ports, and with appropriate valve protection, the motor can tolerate rapid cycling and stall conditions. This combination of wide speed range and bidirectional capability allows a single motor model to serve multiple drive requirements, reducing motor specification diversity in equipment designs.
Application Areas
Marine & Offshore: Trawler winch drives, windlass motors, deck machinery
Construction Equipment: Mini excavator slew drives, crane hoist drives
Industrial Drives: Conveyor drives, mixer drives, metalworking feed drives
Agricultural Machinery: Harvester drive systems, irrigation equipment transmission
Material Handling: Forklift travel drives, winch drives
Heavy-Duty Indirect Drives: Gear drives, belt drives, pulley drives (heavy-duty bearing models 26M/36M/46M/51M recommended)
Expert Maintenance Tips
Installation Guidelines:
Verify the mounting flange face is clean and undamaged. Tighten SAE 2-bolt flange fasteners to Vickers-specified torque values using a calibrated torque wrench.
Apply a thin film of grease to the spline surfaces before coupling installation to prevent dry-assembly wear.
Use SAE 4-bolt flange standard fittings for port connections. Ensure O-rings are intact and correctly seated.
Commissioning & Operation:
Before first startup, fill the motor case with clean hydraulic oil and bleed air. M Series motors can tolerate simultaneous pressurization of case and inlet ports, but case pressure must not exceed shaft seal limits in series applications.
Maintain system fluid cleanliness at NAS Class 9 (ISO 18/16/13) or better. Vane motors are sensitive to particulate contamination, which accelerates vane and cam ring wear.
Avoid sustained operation below 100 r/min. Prolonged low-speed operation may result in inadequate lubrication and stick-slip behavior.
Maintenance Schedule:
Inspect drive cartridge performance every 1000 operating hours. If torque output declines or internal leakage increases, inspect vane-to-cam-ring clearance first.
When replacing the drive cartridge, inspect pressure plate sealing surfaces and bearing condition concurrently. Replace pressure plates if scoring is evident.
Use ISO VG 46 or VG 68 anti-wear hydraulic oil with viscosity range 20–300 cSt. Replace fluid at intervals not exceeding 2000 operating hours or 12 months, whichever comes first.
