Star with round inner core

Overview

Star with Round Inner Core is a specially designed transmission shaft structure that combines the dual advantages of a star profile and a round inner core. This design improves the bending stiffness and installation compatibility of the shaft while ensuring high torque transmission capacity. It is widely used in high-precision transmission, heavy-load machinery, aerospace and other fields.

Structure and Features

(1) Star Profile

The outer surface adopts a **polygonal star (such as 6 stars, 8 stars, 12 stars, etc.)** design to increase the contact area and improve the torque transmission capacity.

The star structure optimizes stress distribution, reduces torsional deformation, and is suitable for high-load conditions.

(2) Round Inner Core

The center part of the shaft maintains a circular cross-section, which is compatible with standard bearings, couplings or hydraulic/pneumatic systems.

The round inner core provides better bending stiffness and reduces vibration during high-speed rotation.

(3) Materials and manufacturing

Material: High-strength alloy steel (such as 42CrMo, 30CrNiMo8), stainless steel (such as 17-4PH) or titanium alloy (such as Ti-6Al-4V) are usually used, suitable for different working conditions (such as corrosion resistance, high temperature environment).

Manufacturing process:

Cold forging/hot forging: improve material density and mechanical properties.

Precision machining: ensure high-precision matching of the star-shaped outer profile and the round inner core.

Surface treatment: such as carburizing and quenching, chrome plating, DLC coating (diamond-like carbon coating) to improve wear resistance.

Core Advantages

Features Traditional solid star shaft Star with round inner core

Torque transmission capacity High Higher (star outer profile optimizes contact surface)

Bending stiffness Average Stronger (round inner core enhances stability)

Weight Heavier Lighter (hollow or composite structure reduces weight)

Compatibility Customized bearings/couplings required Better (round inner core adapts to standard parts)

High-speed balance Dynamic balancing may be required Better (round inner core reduces vibration)

Main applications

(1) Aerospace

Aircraft servo drive shaft: requires high precision, lightweight, and withstands complex loads.

UAV rotor drive: combines high torque and vibration resistance requirements.

(2) Automotive industry

High-performance racing drive shaft: lightweight design, improves power transmission efficiency.

Electric vehicle motor shaft: adapts to high speed and high torque requirements.

(3) Industrial machinery

Robot joint shaft: precision transmission, reduce return error.

CNC machine tool spindle: high rigidity and dynamic balance requirements.

(4) Energy equipment

Wind turbine pitch system: corrosion-resistant and fatigue-resistant design.

Oil drilling tools: withstand extreme torque and impact loads.