A hydraulic support cylinder is an auxiliary pressing and shaping mechanism used in progressive dies for motor stator and rotor core production. It provides controlled support during the stacking of core laminations. By applying hydraulic force beneath the core stack, the cylinder works with the stamping mechanism to press and shape the laminations inside the die.
In conventional core manufacturing, some products require secondary pressing or reshaping after stamping to improve flatness and perpendicularity. An in-die hydraulic support system can integrate part of these operations into the progressive stamping process, reducing the need for subsequent manual work.
Main components of a hydraulic support system
A hydraulic support system generally consists of a hydraulic cylinder, a hydraulic power unit, and a control system. The actual arrangement depends on the die design and production process.
Hydraulic cylinder
The hydraulic cylinder is the system's actuating component. It is generally installed below the working area of the die and applies an upward supporting or preloading force to the laminations through a piston rod and supporting mechanism.
During continuous stamping, the cylinder works with the die's pressing action to support and pre-press the accumulating core laminations. Its stroke, output force, and operating sequence must match the die structure and stamping cycle.
Hydraulic power unit
The hydraulic power unit supplies pressure to the cylinder. It generally consists of an electric motor, hydraulic pump, reservoir, control valves, and pressure adjustment components.
It generates the required system pressure and regulates cylinder force and movement according to the process requirements.
Pressure stability affects the consistency of cylinder operation. The hydraulic settings must therefore be selected according to the core dimensions, stacking arrangement, and die operating conditions.
Control system
The control system coordinates the hydraulic support cylinder with the stamping press and die. Depending on the equipment configuration, it may use a PLC, pressure sensors, position sensors, and control valves to regulate cylinder pressure, stroke, and timing.
On more automated machines, the control system can adjust cylinder operation according to the stamping cycle and core stacking condition. This keeps the support and pre-pressing movements synchronized with lamination stacking.
How the hydraulic support cylinder works in a progressive die
The hydraulic support cylinder improves core stacking quality by providing support and pre-pressing force inside the die. Its operation generally involves the following stages.
Lamination feeding and stacking
The stamping press drives the upper and lower die sections through the stamping cycle. As the electrical steel strip passes through the progressive die stations, the stator or rotor laminations are formed.
For processes with in-die automatic stacking, the punched laminations enter a designated stacking area at the blanking station and are stacked in sequence.
Applying support force from below
As additional laminations enter the die cavity, the hydraulic cylinder applies supporting force from below through its supporting mechanism. This force works with the stamping pressure to maintain the position of the accumulating core stack.
The cylinder pressure and stroke must be determined according to lamination thickness, core structure, stacking method, and die cycle. Excessive pressure may deform the laminations, while insufficient support can result in unstable stacking.
Pre-pressing and shaping inside the die
During continuous stamping and stacking, the hydraulic support cylinder works with the die to pre-press and shape the core. This helps improve the flatness of the core end faces and its overall perpendicularity.
Compared with manual pressing or reshaping after stamping, in-die pre-pressing reduces the need to transfer and reposition the workpiece. It also limits positioning errors caused by repeated handling.
For products using in-die riveting or self-interlocking stacking methods, the cylinder must operate in coordination with the corresponding interlocking features and stacking structure.
Completing the stack and preparing for the next cycle
Once the core reaches the specified stacking condition, the machine performs the required separation, unloading, or subsequent processing operations. The cylinder then returns to its programmed position for the next production cycle.
The exact sequence depends on the progressive die design, core stacking method, and automatic unloading mechanism.
Benefits of hydraulic support cylinders in motor core manufacturing
Improved core flatness and perpendicularity
Motor stator and rotor cores consist of multiple layers of electrical steel laminations. Unstable positioning or compression during stacking can result in uneven end faces, local lifting, and dimensional deviations.
A hydraulic support cylinder applies controlled preloading force inside the die, helping stabilize the stacking process and improve core flatness and perpendicularity.
Reduced secondary pressing and shaping operations
For core designs suitable for in-die pre-pressing, some manual riveting and reshaping operations that would otherwise take place after stamping can be integrated into the progressive die process.
This reduces workpiece transfer, repeated positioning, and manual handling. The actual number of operations that can be eliminated depends on the original manufacturing process and die design.
More consistent production
The hydraulic support cylinder operates in coordination with the stamping press, reducing variations caused by differences in manual pressing force and operator handling.
By controlling pressure, stroke, and operating sequence, the system helps maintain a more consistent stacking process across production batches.
Adaptation to different core designs
Stator and rotor cores used in electric vehicle traction motors, servo motors, and household appliances differ in lamination geometry, material thickness, and stacking structure.
Hydraulic pressure, cylinder stroke, and die support arrangements can be adjusted for different products. However, suitability must be verified through die design and production testing.
Typical applications of hydraulic support cylinders
Hydraulic support cylinders can be used in motor core manufacturing processes that employ progressive stamping and in-die stacking.
Electric vehicle traction motor cores are one example. These products often have demanding requirements for flatness, perpendicularity, stack height, and assembly dimensions. For thin laminations, complex geometries, or core designs prone to stacking deformation, the manufacturing process requires careful control of lamination positioning, stacking pressure, and end-face condition.
In a suitable die design, the hydraulic support cylinder can be installed beneath the core stacking area. Its adjustable support force works with the stamping press to carry out continuous pre-pressing and shaping.
However, lamination gaps, edge lift, stacking factor, and concentricity must be evaluated according to the product drawings, die structure, and inspection results. Fixed values should not be applied to every motor core.
Hydraulic support cylinders versus servo electric cylinders
Some motor core in-die pressing and stacking systems use servo electric cylinders instead of hydraulic cylinders.
A hydraulic support cylinder uses fluid pressure to provide support and pressing force. A servo electric cylinder uses an electric motor and a transmission mechanism such as a ball screw to control movement and force.
The two systems differ in output force, response, positioning control, installation space, and maintenance requirements. Selection should be based on the stamping cycle, die structure, core dimensions, and production process.
Custom machining for motor core dies and related components
Hydraulic support systems and progressive dies for motor stator and rotor cores require various precision structural parts, mounting components, locating parts, and mechanical connectors. We provide custom precision machining based on customer drawings and technical specifications, supporting both individual components and small production batches.
Hansheng Automation also provides drawing-based machining services for components used in other industries. These include yacht structural parts, tobacco packaging machinery components, food filling equipment parts, and precision parts for remote-control racing cars. We manufacture components according to the specified dimensions, tolerances, and machining requirements for different applications.
