BG0405CA050AAAB Parker Torqmotor BG Brake Motor

Product Overview

The Parker Torqmotor™ BG Series BG0405 is a fixed-displacement, low-speed high-torque hydraulic motor designed for demanding hydraulic drive applications. The BG Brake Motor combines the BG hydraulic motor with a wet-disc, spring-applied, hydraulically released brake, providing integrated drive and parking-hold functionality. Parker specifies a standard brake holding capacity of 12,000 lb-in, while the brake release port is rated for pressures up to 3000 psi.

The configurations BG0405CA050AAAB, BG0405CA050AANH, BG0405BS030AAAB and BG0405BS620AAAA share the BG0405 displacement platform, but their mounting, port and shaft codes differ. The complete Parker ordering code must therefore be matched when sourcing a replacement unit. Parker defines the BG configuration through series, displacement, mounting, ports, shaft, rotation and options.

The BG0405 frame provides 405 cm³/rev displacement, up to 172 bar continuous differential pressure, and a maximum operating speed of 232 rpm. Parker data specifies approximately 942 Nm continuous torque and 1342 Nm intermittent torque for the documented BG0405 BS configuration.

Technical Specifications

BG0405 Engineering Data

• Brand: Parker Hannifin
• Product Family: Torqmotor™ BG Series Brake Motor
• Type: Fixed Displacement LSHT Hydraulic Motor
• Primary Model: BG0405CA050AAAB
• Related Models: BG0405CA050AANH
• Related Models: BG0405BS030AAAB
• Related Models: BG0405BS620AAAA
• Geometric Displacement: 405 cm³/rev
• Displacement: 24.7 in³/rev
• Maximum Continuous Differential Pressure: 172 bar / 2500 psi
• Maximum Intermittent Differential Pressure: 241 bar / 3500 psi
• Maximum Supply Pressure: 300 bar / 4350 psi
• Maximum Continuous Oil Flow: 76 L/min / 20 gpm
• Maximum Intermittent Oil Flow: 95 L/min / 25 gpm
• Maximum Operating Speed: 232 rpm
• Maximum Continuous Torque: 942 Nm / 8336 lb-in
• Maximum Intermittent Torque: 1342 Nm / 11877 lb-in
• Minimum Continuous Starting Torque: 791 Nm / 7002 lb-in
• Minimum Intermittent Starting Torque: 1145 Nm / 10133 lb-in
• Maximum Side Load: 16,000 N / 3,597 lb
• Maximum Performance: 27 kW / 37 HP
• Brake Type: Wet-disc, spring-applied, hydraulically released
• Standard Brake Holding Capacity: 12,000 lb-in
• Brake Release Port: Up to 3000 psi
• Displacement Control: Fixed displacement
• Rotation: Determined by complete model code; 0 = Standard Rotation
• Shaft Code 03: 1-1/4″ Keyed Shaft
• Shaft Code 05: 1-1/4″ 14-Tooth Spline
• Shaft Code 62: SAE 14-Tooth Spline
• AAAB: No Paint
• AAAA: Black Paint

BG0335 Reference Data

For the BG0335 model listed in your original product title:

• Displacement: 337 cm³/rev / 20.6 in³/rev
• Maximum Continuous Pressure: 207 bar / 3000 psi
• Maximum Operating Speed: 277 rpm
• Maximum Continuous Output Torque: 965 Nm
• BG Series Brake Holding Capacity: 1000 Nm
• Standard BG Motor Weight: 16.3 kg

The standard BG motor weight should not be confused with the weight of a complete BG Brake Motor assembly, because the integrated brake and mounting configuration add significant mass. Parker provides separate dimensional and weight data for the brake-motor mounting configurations.

Key Technical Advantages

High-Displacement LSHT Architecture

With 405 cm³/rev displacement and a maximum operating speed of 232 rpm, BG0405 is optimized for low-speed, high-torque hydraulic power transmission rather than high-speed operation. This makes it suitable for heavy-duty rotational mechanisms where controlled low-speed movement is required.

High Starting Torque

The documented BG0405 configuration provides 791 Nm continuous starting torque and up to 1145 Nm intermittent starting torque. This characteristic is particularly valuable when starting against static friction, high inertia or transient mechanical loads.

High-Pressure Capability

BG0405 supports up to 172 bar continuous differential pressure and 241 bar intermittent differential pressure, while Parker specifies a maximum supply pressure of 300 bar. These limits must be evaluated separately during hydraulic system design to prevent overstressing the motor.

Integrated Wet-Disc Brake

The BG Brake Motor incorporates a spring-applied, hydraulically released wet-disc brake. Hydraulic pressure releases the brake during operation, while loss of release pressure allows the spring mechanism to reapply the brake. This architecture is well suited to machinery requiring parking or holding capability.

High Side-Load Capability

The BG0405 documentation specifies a maximum side load of 16,000 N. Parker also provides bearing-life guidance based on ISO 281 L10 calculations, making side-load analysis essential in sprocket, pulley and external gear applications.

Flexible Shaft and Mounting Configurations

Parker provides several shaft configurations, including keyed and spline arrangements. The different shaft and mounting/port combinations explain the configuration differences between BG0405CA050AAAB, BG0405BS030AAAB and BG0405BS620AAAA.

Application Areas

Typical applications for the Parker BG0405 Brake Motor include:

• Heavy-duty construction machinery
• Hydraulic wheel-drive systems
• Winches and hoisting equipment
• Heavy-duty conveyors
• Material handling machinery
• Agricultural machinery
• Forestry equipment
• Road construction machinery
• Industrial rotary drives
• Hydraulic wheel-drive applications
• Machinery requiring parking or holding capability

Final selection should always be based on actual pressure, flow, speed, torque, starting load, duty cycle and shaft side-load requirements.

Expert Maintenance Tips

Verify the Complete Model Code

Do not select a replacement based only on BG0405. Confirm the complete code, including mounting, ports, shaft, rotation and option suffix. Parker’s ordering system explicitly defines the motor through these configuration blocks.

Match the Shaft Configuration

The 03, 05 and 62 shaft codes represent different output-shaft configurations. Keyed and spline connections require different mechanical interfaces, so the shaft must be physically matched with the driven component.

Verify Brake Release Pressure

The brake-release circuit must be checked independently from the main motor circuit. Insufficient release pressure can cause brake drag, excessive friction and unnecessary heat generation.

Control External Radial Loads

When using a sprocket, pulley or external gear, calculate the radial shaft load and the distance from the mounting face. Torque capacity alone is not sufficient for bearing-life verification. Parker’s bearing guidance should be incorporated into the mechanical design.

Verify Brake Re-Application

After installation or service, confirm that the brake fully releases under hydraulic pressure and properly reapplies when release pressure is removed. This is especially important on machines carrying suspended or elevated loads.

Perform 100% Simulated Operating-Condition Testing

For replacement BG0405 units, a professional QA procedure should include 100% simulated-condition testing under the customer’s intended pressure, flow, speed, torque and brake-release conditions. Functional inspection should also verify shaft rotation, hydraulic sealing, abnormal noise, temperature rise and configuration compatibility.