Browse Topic: Driveshafts

Items (28)
This SAE Aerospace Recommended Practice (ARP) is an application guide for fixed and variable displacement hydraulic motors. It provides details of the characteristics of fixed and variable displacement hydraulic motors, architectures, circuit designs, controls, and typical applications. The applications include airborne and defense vehicles with emphasis on high performance applications.
A-6C4 Power Sources Committee
A system of passive balancing devices could potentially be used to suppress vibrations in helicopter tailrotor driveshafts. Passive balancing devices for rotary shafts consist of masses restricted by concentric guides about the shaft axis. At supercritical shaft speeds, the balancing masses automatically adjust to counter imbalance due to uneven load distribution. The problem is highly nonlinear and requires comprehensive modeling to achieve satisfactory prediction of the balancing behavior. A frequency-scaled tailrotor driveshaft test rig was fabricated to test the performance of a passive balancing device and to validate a comprehensive model. The model includes balancing mass collisions and balancing mass interaction with the balancer track through friction. Experimentally, the passive balancing device on average reduced driveshaft transverse vibrations by 62% at steady-state. Models available in the literature predicted vibration amplitudes to within 68% of the experimental values. The new balancing model improved the prediction of shaft vibration amplitudes by a factor of 3.9 when compared to published models (18% vs. 68%). This suggests that friction and mass collisions cannot be ignored in passive balancer modeling and that passive balancing is a viable solution for suppressing driveshaft vibrations.
Haidar, AhmadPalacios, Jose
ABSTRACT Thermoplastic composite driveshafts have demonstrated a 35% weight reduction and over 150% greater post ballistic damage survivability over legacy aluminum designs. This was achieved through the joint efforts of Automated Dynamics, NAVAIR, SURVICE Engineering, UTAS, and Sikorsky under a Small Business Innovation Research (SBIR) Phase II effort. An evolution of previous efforts, this paper describes subsequent work to optimize laminate architecture, materials, and structural qualifications to meet new performance requirements. SURVICE Engineering optimized the design of the driveshafts to meet new performance requirements supplied by Sikorsky. Automated Dynamics used its recently updated additive manufacturing process using high performance thermoplastic composites to rapidly manufacture prototype driveshafts. UTAS assembled and tested the composite driveshafts. The end goal is a high performance composite driveshaft that is a drop-in replacement for the legacy aluminum driveshaft. Driveshafts were tested to advance the program to a Technology Readiness Level (TRL) of 6.
Michasiow, JohnAugust, ZacharyHauber, David
ABSTRACT Testing was recently performed on a new tail rotor drive shaft (TRDS) technology developed under the Future Advanced Rotorcraft Drive System (FARDS) program. The FARDS TRDS operates above its third critical speed, has a curved shaft centerline, and utilizes a novel damper design, advanced materials, and advanced manufacturing technologies. This TRDS design allows for a reduction from seven shaft segments to only two, which reduces system weight and cost. The endurance, low cycle fatigue, and high cycle fatigue testing performed on this drive shaft design was successful, and demonstrated a Technology Readiness Level (TRL) 6.
Baker, TrevenChavez, AndreaFetty, JasonSpears, Steven
Product for which data is to be available is for class 6 and larger, i.e., gross vehicle weight > 9.6 kg (19 500 lb).
Truck and Bus Powertrain Committee
A recent Phase II SBIR program focused on improving the survivability of driveshafts in rotorcraft applications while decreasing their weight. Thermoplastic composites were identified as a candidate material for achieving the goals of the program and a design was developed utilizing data from many previous sources and designs. Driveshafts were manufactured and validated against predicted static torque loads after withstanding a ballistic impact. The shafts showed a significant improvement in post-damaged strength over the legacy aluminum design with a weight reduction greater than 30%, exceeding all program goals. Automated Dynamics utilized recent process advancements in manufacturing both test coupons and driveshafts. This process takes advantage of unique aspects of in-situ composite consolidation to improve the bond affected between subsequent plies of pre-impregnated fiber reinforced thermoplastic materials on a continuous basis. Coupon test results demonstrated a 52% reduction in void content and greatly improved mechanical properties, further improving the performance over aluminum and thermoset composite driveshafts.
Michasiow, JohnAugust, Zachary
Passenger Car and Light Truck Automatic Transmission and Automatic Transaxle Test CodeJ651_200506 (Historical)6/22/2005
To provide a means of obtaining the performance characteristics of automatic transmissions and automatic transaxles. It outlines dynamometer tests that map the steady-state characteristics over a range of operations of an automatic transmission/automatic transaxle and provides a method of presenting test data. This procedure must be followed, with similar test facilities so that results obtained from different laboratories are comparable. For this SAE Recommended Practice, the transmission is defined as the complete automatic transmission or transaxle assembly between the engine and the driveshaft(s) used to effect a ratio change in transmitting power. This test procedure deals with the aspect of conducting complete transmission and transaxle assembly testing. However, by its very nature a transmission should be viewed as a compilation of three major component systems: pump, torque converter, and gearbox (all ratio change elements). From a design perspective, it is important that the losses associated with each of these components be determined by conducting separate tests of each component under controlled test conditions that simulate the in-transmission operating conditions. Torque converter testing is described in SAE J643. If done with strict attention to detail it is possible to subtract off the pump and torque converter losses from the transmission assembly losses in order to obtain gearbox losses only, eliminating the need to conduct a separate gearbox test.
Automatic Transmission and Transaxle Committee
A case study of the application of shape optimization technique to the design of the third cross-member of an automotive chassis has been presented. Its fundamental frequency is only marginally higher than the maximum operating frequency of the transmission and drive shaft, which are mounted on this cross-member. The objective is to raise the cross-member frequency as high as possible so that there is no resonance and resulting fatigue damage. A sizing optimization indicated that the mass was a predominant factor. Shape optimization using approximate direct linearization method was performed and a number of design directions were obtained. The fundamental frequency of the cross-member was raised by about 4 Hz.
Krishna, Murali M.R.
Passenger Car and Light Truck Automatic Transmission and Automatic Transaxle Test CodeJ651_199601 (Historical)1/1/1996
To provide a means of obtaining the performance characteristics of automatic transmissions and automatic transaxles. It outlines dynamometer tests that map the steady-state characteristics over a range of operations of an automatic transmission/automatic transaxle and provides a method of presenting test data. This procedure must be followed, with similar test facilities so that results obtained from different laboratories are comparable. For this SAE Recommended Practice, the transmission is defined as the complete automatic transmission or transaxle assembly between the engine and the driveshaft(s) used to effect a ratio change in transmitting power. This test procedure deals with the aspect of conducting complete transmission and transaxle assembly testing. However, by its very nature a transmission should be viewed as a compilation of three major component systems: pump, torque converter, and gearbox (all ratio change elements). From a design perspective, it is important that the losses associated with each of these components be determined by conducting separate tests of each component under controlled test conditions that simulate the in-transmission operating conditions. Torque converter testing is described in SAE J643. If done with strict attention to detail it is possible to subtract off the pump and torque converter losses from the transmission assembly losses in order to obtain gearbox losses only, eliminating the need to conduct a separate gearbox test.
Automatic Transmission and Transaxle Committee
Analysis of an Automotive Driveline with Cardan Universal Joints9508952/1/1995
A detailed methodology is presented in this paper for a complete assessment of various forces, torques, and kinematic effects due to universal joint angularities and shaft yoke phasing. A modular approach has been adopted wherein constitutive equations represent each of the key elements of a driveline namely the driveshaft, coupling shaft, universal joint, and the transmission/axle shafts. Concentrated loads are used wherever loads are being transferred between the elements of a driveline. Local matrices are developed for the equilibrium of the respective driveline members. The local matrices are then assembled into a global matrix and solved for the kinematic state of the complete driveline. A 6x15 matrix has been developed to represent a general shaft in the system and a 6x10 matrix has been developed for a universal joint cross. This gives us a complete picture of all the loads on all driveline members. The calculated bearing loads can then be used to appropriately design or select the trunnion and center bearings. The developed approach can accommodate angularity changes in three dimensions. Thus a very general algorithm has been developed to address driveline issues encountered in practice. Experimental studies have been conducted on a truck driveline and the vibratory response of the driveline was recorded. In addition, computer simulations have been undertaken to predict the vibratory response of the same driveline. Results from both the studies are presented in this paper.
Szadkowski, AndrewPrange, EdwardVedam, KumarNaganathan, Nagi G.
Efficiency of Constant Velocity Universal Joints9309063/1/1993
Efficiency of Driveshafts have not been analyzed in great detail in the past due to their relatively high efficiency. However, it is possible to obtain about a 0.1 percent increase in fuel economy by decreasing driveshaft torque losses by about 20 percent, owing to the combination mode fuel calculation. In order to improve fuel economy it is necessary to increase the efficiency of the constant velocity universal joint (C.V.J.) used for driveshafts. Additionally, propeller shafts with improved heat characteristics are required. It is for these reasons that this project is conducted. In this paper, the motion of two typical joint used for front-engine, front-drive passenger cars is analyzed geometrically and efficiency formulas are derived. One of the joints is a Rzeppa joint, used on the wheel side of the driveshaft and the other is a tripot joint, used on the differential side. These formulas are then verified by experiment. It is found that about 70 percent of frictional induced losses in a Rzeppa joint are due to internal friction caused by contact of the inner and outer spherical surface with the cage. Similarly 70 percent of frictional induced losses in a tripot joint are caused by internal friction which is a result of contact between the balls and the grooves of the housing. Therefore, the motivation to improve fuel economy and heat characteristics can be seen.
Yamamoto, TakeoMatsuda, TakashiOkano, Nobuhiko
Passenger Car and Light Truck Automatic Transmission and Automatic Transaxle Test CodeJ651_199101 (Historical)1/23/1991
To provide a means of obtaining the performance characteristics of automatic transmissions and automatic transaxles. It outlines dynamometer tests that map the steady-state characteristics over a range of operations of an automatic transmission/automatic transaxle and provides a method of presenting test data. This procedure must be followed, with similar test facilities so that results obtained from different laboratories are comparable. For this SAE Recommended Practice, the transmission is defined as the complete automatic transmission or transaxle assembly between the engine and the driveshaft(s) used to effect a ratio change in transmitting power. This test procedure deals with the aspect of conducting complete transmission and transaxle assembly testing. However, by its very nature a transmission should be viewed as a compilation of three major component systems: pump, torque converter, and gearbox (all ratio change elements). From a design perspective, it is important that the losses associated with each of these components be determined by conducting separate tests of each component under controlled test conditions that simulate the in-transmission operating conditions. Torque converter testing is described in SAE J643. If done with strict attention to detail it is possible to subtract off the pump and torque converter losses from the transmission assembly losses in order to obtain gearbox losses only, eliminating the need to conduct a separate gearbox test.
Automatic Transmission and Transaxle Committee
Passenger Car and Light Truck Automatic Transmission and Automatic Transaxle Test CodeJ651C_197906 (Historical)6/1/1979
To provide a means of obtaining the performance characteristics of automatic transmissions and automatic transaxles. It outlines dynamometer tests that map the steady-state characteristics over a range of operations of an automatic transmission/automatic transaxle and provides a method of presenting test data. This procedure must be followed, with similar test facilities so that results obtained from different laboratories are comparable. For this SAE Recommended Practice, the transmission is defined as the complete automatic transmission or transaxle assembly between the engine and the driveshaft(s) used to effect a ratio change in transmitting power. This test procedure deals with the aspect of conducting complete transmission and transaxle assembly testing. However, by its very nature a transmission should be viewed as a compilation of three major component systems: pump, torque converter, and gearbox (all ratio change elements). From a design perspective, it is important that the losses associated with each of these components be determined by conducting separate tests of each component under controlled test conditions that simulate the in-transmission operating conditions. Torque converter testing is described in SAE J643. If done with strict attention to detail it is possible to subtract off the pump and torque converter losses from the transmission assembly losses in order to obtain gearbox losses only, eliminating the need to conduct a separate gearbox test.
Automatic Transmission and Transaxle Committee
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