Core Summary
A hydraulic rotary actuator is a device that converts the linear motion of a hydraulic cylinder into rotational output, commonly used for angular positioning of turntables, fixtures, and valves. The rack-and-pinion type is a common structure, where two hydraulic cylinders push the rack, which in turn drives the gear to output torque. Conforti's HR/MR series falls into this category, with a working pressure of 100 bar, torque up to 120 daNm, and a rotational angle coverage of 90°–270°.
1. Basic Operating Principle
Linear motion to rotary motion
The rack-and-pinion rotary actuator features two parallel hydraulic cylinders inside, with the piston connected to the rack. When hydraulic oil pushes the piston, the rack translates and drives the gear meshed with it to rotate, thereby outputting rotary motion and torque. Compared to directly using a cylinder to push the rocker arm, this structure offers controllable angles and stable force output.
Corner travel limit
The rotation angle is determined by the piston stroke and the number of gear teeth. Common angles include 90°, 180°, 270°, etc. The end of the stroke is usually equipped with a buffer to reduce impact upon reaching the position.
II. Main Structural Features
Rack and pinion type
The Conforti HR/MR series features a compact structure, high output torque, and excellent angular repeatability, making it ideal for applications where space is limited but substantial output is required. This series adopts this structure and can be equipped with a magnetic piston to facilitate position detection with proximity switches.
Blade Type (Comparison)
Another common structure is the vane type, which relies on the rotation of vanes oscillating within a cavity to output torque. It has a small size but poses high sealing challenges. The gear and rack type often has advantages in terms of torque and lifespan, making it one of the mainstream choices in the industrial sector.
III. Key Parameters
Torque and Pressure
The output torque increases as the supply pressure rises. For HR/MR operating at a pressure of 100 bar, the torque is approximately 120 daNm. When selecting a model, allow for a margin based on the peak torque under harsh operating conditions, rather than relying on the average value.
Rotation angle and buffering
Commonly used angles range from 90° to 270°, with a buffer at the end of the travel. When a larger angle is required, it is necessary to confirm whether the structure can support it, to avoid damaging the seal by forcibly exceeding the limit.
Installation and Loading
The output shaft has limited capacity to withstand radial and axial loads. External loads should be borne primarily by the bearings, rather than being fully imposed on the output shaft. Otherwise, it will accelerate wear and affect angular accuracy.
IV. Typical Applications
Turntable and indexing
Rotating actuators are commonly used to achieve directional rotation on machining center turntables and assembly line indexing disks, and are paired with proximity switches for position detection.
Clamps and Valves
The clamping and flipping of fixtures, as well as the opening and closing of pipeline valves, can all be achieved through the angular movement of rotary actuators. These actuators are more resistant to impact and better suited to oily environments than systems that utilize motors combined with speed reducers.
Parameter Table (Terminology Comparison)
> The above content is based on the Conforti HR/MR rotary actuator product information. Specific parameters are subject to the original manufacturer's documentation. QN TECHNOLOGY provides support for HR/MR series selection.
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