Browse Topic: Cardan joint

Items (19)
The following definitions and illustrations are intended to establish common nomenclature and terminology for driveshafts and their articulating joints used in various drivetrain applications. In addition, useful guidelines are included for the application of driveshafts and their joints. For more specific details, refer to AE-07.
Drivetrain Standards Committee
Rotational Vibration Test Apparatus for Laser Vibrometer Verification2021-01-10968/31/2021
Prior to making rotational vibration measurements with a laser vibrometer, it is good practice to establish that the instrument is operating properly. This can be accomplished by comparative measurement of a rotational vibration source with known amplitude and frequency. This paper describes the design and development of a rotational vibration apparatus with known amplitude and frequency to be used as a reference for comparison to concurrent and co-located measurements made by a rotational laser vibrometer (RLV). The comparative measurements acquired with the apparatus are helpful to verify proper laser vibrometer operation in between regular calibration intervals, and/or whenever the functionality of the vibrometer is suspect. In the subject apparatus, a Cardan shaft with variable input speed and angle is used to provide output torsional vibration with variable frequency and amplitude. Previously derived equations of motion for Cardan joints are used to estimate operating amplitude versus speed relationship for the apparatus. To provide an independent rotational vibration measurement for comparison to the laser, a ferromagnetic toothed wheel and magnetic pickup are used. The design of the Cardan shaft and adjustable support table are described, followed by the design of the variable speed electric drive system and controller. For the finished apparatus, example operating data from the reference sensor are compared to laser vibrometer data, and to the theoretical prediction of output torsional velocity from the Cardan joint equations of motion. Finally, suggestions for future work are provided. The development and verification of rotational tuned vibration absorbers is provided as a potential additional application of the apparatus.
Gehringer, Mark
Automotive vehicles equipped with Cardan joints may experience low frequency vehicle launch shudder vibration (5-30Hz) and high frequency driveline moan vibration (80-200Hz) under working angles and speeds. The Cardan joint introduces a 2nd order driveshaft speed variation and a 4th order joint articulation torque (JAT) causing the vehicle shudder and moan NVH issues. Research on the Cardan joint induced low frequency vehicle shudder using a Multi-Body System (MBS) method has been attempted. A comprehensive MBS method to predict Cardan joint induced high frequency driveline moan vibration is yet to be developed. This paper presents a hybrid MBS and Finite Element Analysis (FEA) approach to predict Cardan joint induced high frequency driveshaft moan vibration. The CAE method considers the elastically coupled driveshaft bending and engine block vibration due to Cardan joint excitation. Detailed driveshaft, joints, slip mechanism, differential, axle and wheels were modeled using a MBS modeling tool. The FEA engine block model was imported using the Craig-Bampton method. The CAE driveshaft bending frequency was verified with the Euler-Bernoulli beam equation and with a driveshaft impact test. CAE order cut vibrations at driveline attachment points were correlated with Dyno test-rig measurements as well as with vehicle test data under various operating conditions. This method was used to optimize the Cardan joint induced driveshaft moan performance up front in the development process, with the benefits of reducing hardware testing needs, avoiding late issues, and allowing a more cost effective design to be explored before hardware prototypes were built.
Liu, Jack S.P.Remisoski, NatalieIqbal, JavedEgenolf, Robert
The Cardan joint of a steerable beam front axle is a complicated mechanical component. It is subjected to drive torque, speed fluctuations, and joint articulation due to powertrain inputs, steering, and suspension kinematics. This combination of high torque and speed fluctuations of the Cardan joint, due to high input drive torque and/or high steer angle maneuvers, can result in premature joint wear. Initially, some observations of premature wear were not well understood based on the existing laboratory and road test data. The present work summarizes a coordinated program of computer modeling, vehicle Rough Road data acquisition, and physical testing used to predict the joint dynamics and to develop advanced testing procedures. Results indicate analytical modeling can predict forces resulting from Cardan joint dynamics for high torque/high turn angle maneuvers, as represented by time history traces recorded in rough road data acquisition. This new approach can then be used to size the joint for durability, thus improving the life of the Cardan joint and preventing premature wear.
Thom, GeraldSheets, AlanBrendel, Frederick F.Long, Kah Wah
Development of a Multi-Body Systems Approach for Analysis of Launch Shudder in Rear Wheel Driven Vehicles2009-01-20735/19/2009
Driveline shudder is a low-frequency (10 Hz - 30 Hz) vibration issue of vehicles that can occur under various test conditions. Specifically, launch shudder is an issue that can be prevalent under vehicle take-off conditions. Factors that typically contribute to launch shudder include stick-slip excitation of friction materials (clutches) and driveline excitations, in particular, on rear wheel drive (RWD) vehicles. Shudder caused by the driveline excitation is generally related to the universal joints (Cardan joints) in the driveline system. In this case, the u-joint forces and kinematics induce a 2nd order excitation when operated under a driveline angle. This document focuses on launch shudder phenomena resulting from driveline system excitation on a RWD vehicle. An initial treatment of the physics governing launch shudder and typical factors influencing the shudder levels in vehicle are provided. Following this, the development of a multi-body systems (MBS) based approach is described. The results from the model are shown to correlate well with experimental measurements on a test vehicle. Upon demonstrating good correlation, the MBS model is utilized to conduct sensitivity analyses with respect to key design factors that influence launch shudder. Finally, the results are summarized and suitable conclusions provided.
Wellmann, ThomasGovindswamy, Kiran
The following definitions and illustrations are intended to establish common nomenclature and terminology for universal joints and driveshafts used in various driveline applications. In addition, useful guidelines are included for the application of universal joints and driveshafts. For more specific details, see Universal Joint and Driveshaft Design Manual, AE-7.
Drivetrain Standards Committee
The following definitions and illustrations are intended to establish common nomenclature and terminology for universal joints and driveshafts used in various driveline applications. In addition, useful guidelines are included for the application of universal joints and driveshafts. For more specific details, see Universal Joint and Driveshaft Design Manual, AE-7.
Driveline Standards Committee
Simulation of Torque Characteristics in Drivelines with Universal Joints8210272/1/1982
The variations of torque in drivelines with single and double cardan U-joints in a 4-wheel-drive articulated farm machine in motion have been studied by computer simulation. A mass elastic model for an engine, power train and the machine is used for the simulation. The effects of tire slips and traction parameters on torque variation of drive shafts have also been included in the study. The torque in drive train input drive shaft with single U-joints having large angular unequality for 40 deg. articulation and 15 deg. oscillation about center pivot has shown severe fluctuations with reversals. The yoke accelerations are also beyond acceptable values. The power train output shaft does not show much of a torque variation because of lower speed and effective inertias and stiffnesses. The driveline torque variation is reduced when the angular unequality is made smaller. The use of double cardan joints with as high a joint angle as 32.5 deg. is found to have lowered the torque fluctuation and has eliminated the torque reversals in the drive train input shaft. The angular accelerations of yokes have also been drastically reduced. The effects of initial tire slips and coefficients of traction are found to be negligible on the torque characteristics of the drive train input shaft. The effects are larger on the torque variations of the front output shaft. The study has further shown that for the same degree of oscillation as above, a double cardan joint would be needed to reduce the torque fluctuation in the PTO input drive shaft.
Kar, Malay K.
Driveline Standards Committee
AC-9 Aircraft Environmental Systems Committee
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