Bosch Rexroth Hägglunds CA series hydraulic motor

The Hägglunds CA series is a line of low-speed, high-torque radial piston hydraulic motors manufactured by Bosch Rexroth under the Hägglunds brand. It's designed to deliver direct-drive rotational power without the gearboxes, couplings, and maintenance overhead that mechanical or electromechanical drivetrains typically require.

Where the Hägglunds Name Comes From

The brand traces back to Hägglund & Söner, a Swedish engineering company headquartered in Örnsköldsvik. Bosch Rexroth acquired the hydraulic motor business formerly owned by Hägglund & Söner in 2011, and the company still manufactures products under the Hägglunds brand at the original Örnsköldsvik manufacturing base. That heritage matters in practice: the CA series inherits decades of radial piston motor design experience originally developed for demanding Scandinavian forestry, mining, and marine equipment.

Where CA Fits in the Broader Hägglunds Lineup

Bosch Rexroth organizes its Hägglunds motors into several families by torque class and application — the CA (Compact) series sits alongside the larger CB, CBM, and Quantum (QMX/QM) series. The CA line is generally the more compact, mid-torque option, while larger Quantum and CB motors handle the heaviest-duty, highest-torque jobs like mine hoists and large mixers.

How a Hägglunds CA Motor Actually Works

Unlike an axial piston motor or a standard gear motor, the CA series is a radial piston motor: pistons are arranged around a central shaft in a star pattern rather than parallel to it. Hydraulic fluid pressurizes each piston in sequence, pushing against a cam ring or eccentric to generate rotational torque directly at low speed — no reduction gearbox required.

Built-In Symmetry and Shock Tolerance

One of the defining traits of the design is a built-in ability to withstand shock loads, combined with perfect internal symmetry. That symmetry isn't a cosmetic detail — it ensures consistent torque throughout each revolution and a balance of internal forces that minimizes noise and vibration. In a mill, crusher, or winch that experiences constant load spikes, that internal balance is what keeps bearings and seals alive for years instead of months.

Full Torque and Full Speed, Simultaneously

Most drive technologies force a trade-off: you get full torque or full speed, rarely both, and rarely indefinitely. The CA series is built so full speed and full torque are available simultaneously, and both can be sustained for an indefinite period of time — a property that matters enormously in continuous-duty industrial processes where the motor never really gets to idle.

Where CA Series Motors Are Used

Plastics and Injection Molding

The initial market focus for the redesigned CA 10–40 series was injection molding machinery in the plastics industry, since a large share of that market's demand sits at 50 Nm/bar of specific torque and below — squarely inside the compact motors' new operating window. In practice, this means clamping and injection units that once relied on hydraulic cylinders or electric servo drives can use a CA motor to deliver precise, high-force rotary motion in a much smaller footprint.

Marine, Offshore, and Mobile Machinery

Beyond plastics, Bosch Rexroth identified marine and offshore equipment, mobile machinery, and recycling as future application areas for the expanded CA line. Winches, thrusters, and deck machinery all benefit from a motor that can take shock loading from waves and cargo handling without a gearbox failure derailing an entire vessel's operation.

Heavy Process Industries: Rolling Mills and Mixers

Perhaps the clearest real-world proof point comes from the rubber processing industry. At its Berlin facility, Freudenberg Sealing Technologies retrofitted a roll mill's electromechanical drive with a speed-controlled direct drive from Bosch Rexroth using a Hägglunds hydraulic motor, working with system integrator MaTech. According to Marek Semrau, Senior Global Process Engineer at Freudenberg, the performance characteristics required for the application were a strong argument in favor of the hydrostatic direct-drive approach, even as energy-efficiency pressure has pushed some competitors toward electromechanical alternatives in recent years.

Installation and Maintenance Considerations

A few practical points worth flagging for anyone specifying or maintaining a CA series motor:

Fluid cleanliness is non-negotiable. Radial piston motors have tight internal tolerances; contamination control (filtration, regular oil analysis) has an outsized effect on service life.

Mounting interface selection matters early. Since torque can be configured via different mechanical interfaces, confirm the mounting and shaft configuration against the driven equipment before ordering — retrofitting later is far more expensive than specifying correctly up front.

Match displacement to duty cycle, not just peak torque. Continuous full-torque, full-speed operation is a strength of this series, but pump sizing and system pressure still need to be matched to the actual duty cycle to avoid running the hydraulic power unit inefficiently.

Plan for periodic seal and bearing inspection, especially in shock-load-heavy applications like mills and crushers, where wear is cumulative even if the motor itself rarely fails outright.

For more information on the CA hydraulic motor, please visit https://www.baolilaihydraulic.com/product/.

Specifications

1) Calculated as: Metric= Ts·(350-15)· 0,98

2) Viton seals are recommended for speeds above 280 rpm

3) The motors are designed according to DNV-rules. Test pressure 420 bar. Peak pressure 420 bar maximum, allowed up to 10000 times.

4) Flushing of motor case is required. See section 4.10: Flushing

Selection Table