Cardan Shafts

Cardan shaft is a mechanical transmission device used to connect two axes that do not coincide but require the transmission of motion and torque. The uniqueness of this coupling lies in its ability to compensate for angular deviations between two shafts within a certain range of angles, while maintaining the continuity of power transmission. The core of a cardan shaft is a cross axis structure, with four shaft necks connected to two fork shaped joints through needle roller bearings. When the driving shaft rotates, the motion is transmitted to the driven shaft through the transmission of the cross shaft, and it can work normally even if there is a certain angle deviation between the two shafts.

Typical Structure and Types of cardan shafts

The common cardan shafts in modern engineering mainly have the following structural forms:

• Cross cardan shaft:
  The most basic form consists of two fork shaped joints and a cross axis
  Single use can cause speed fluctuations, usually used in pairs to eliminate this effect
  Widely used in automotive transmission systems

• Cage type constant velocity cardan shaft:
  Using a spherical cage and multiple steel balls to transmit torque
  Can achieve true constant speed transmission
  Standard configuration of modern front wheel drive vehicles

• Double cardan shaft:
  Combination of two single cardan shafts, connected through an intermediate shaft
  Can eliminate speed fluctuations, suitable for large angle transmission

• Flexible cardan shaft:
  Replacing metal hinges with elastic components
  Capable of absorbing vibrations and impacts, suitable for precision transmission applications

Key performance parameters of cardan shaft

Choosing a suitable cardan shaft requires consideration of the following key parameters:

• Allowable torque: The maximum torque value that the coupling can safely transmit
  

• Maximum speed: the maximum speed limit while ensuring reliable operation
  

• Compensation angle: The maximum angle between two axes that can work normally (usually 15 ° -25 ° per section)
  

• Transmission efficiency: generally above 98%, but slightly decreases with increasing angle
  

• Working life: usually calculated in hours or rotations, greatly affected by lubrication conditions

Application fields of cardan shaft

The unique performance of cardan shafts makes them widely used in many industrial fields:

• Automotive industry:
  The transmission shaft connects the gearbox and the drive axle
  Half axle connection of front wheel drive vehicles
  cardan shaft in steering system

• Industrial Machinery:
  Power transmission of large equipment such as rolling mills and paper machines
  Connection between machine tool spindle and drive motor
  Joint transmission of industrial robots

• Aerospace:
  Transmission device of aircraft control system
  Helicopter rotor transmission system

• Ship engineering:
  Connection between propeller shaft and main engine
  Power transmission of deck machinery

Selection considerations:

• Power and torque requirements of the transmission system
  

• Offset type between two axes (angle, radial or axial)
  

• Working environment (temperature, corrosiveness, dust, etc.)
  

• Do you need electrical insulation or explosion-proof characteristics
  

• Maintenance convenience and expected service life

Maintenance suggestions:

• Regular lubrication: Cross shaft bearings need to be regularly lubricated with high-temperature resistant grease
  

• Check for wear: Regularly inspect the wear of the cross shaft, bearings, and seals
  

• Dynamic balance: Ensure the dynamic balance performance of the coupling during high-speed applications
  

• Protective measures: Protective covers should be installed in harsh environments
  

• Alignment check: Regularly check the alignment of the two axes to avoid excessive deviation

As an important component in the field of mechanical transmission, the performance of cardan shafts directly affects the reliability and efficiency of the entire transmission system. The correct selection, installation, and maintenance of cardan shafts are of great significance for ensuring the long-term stable operation of equipment. With the development of Industry and intelligent manufacturing, cardan shaft technology will continue to innovate to meet increasingly stringent industrial application requirements.