Browse Topic: Transmissions

Items (7,003)
Due to manufacturing, assembly, and actuator wear, slight deviations between the actual and logical positions of various gears in a transmission system may accumulate, affecting shift quality, reducing shift accuracy, and causing operational anomalies. To address this issue, a self-learning method based on the top dead center (TDC) and lower dead center (LDC) was proposed, specifically for the hybrid gearbox of an electric torque converter (eTC) module and a double-input shaft gearbox (DIG). The linear active disturbance rejection control (LADRC) method was employed to estimate and manage the nonlinear resistance during the motion of the shifting motor. To simplify the controller parameter problem, the nutcracker optimization algorithm (NOA) was utilized to tune the LADRC parameters, thereby optimizing the position self-learning process. The control strategy was modeled using MATLAB/SIMULINK, and its reasonableness was verified through hardware-in-the-loop (HIL) tests. Based on these
Hong, HanchiQuan, Kangningd’Apolito, LuigiXu, Li
The SAE Formula prototypes are developed by students, where in the competition, various aspects of project definitions are evaluated. Among the factors evaluated for scoring is the braking system, in which the present work aims to present the development and design of the braking system of a vehicle, prototype of Formula SAE student competition. As it is a project manufactured mostly by students, where the chassis, suspension system, electrical, transmission and powertrain are developed, it is important to first pass the static and safety tests, where the brakes of the four wheels are tested during deceleration at a certain distance from the track. To enable such approval and also to demonstrate, for the competition judges, the veracity of the system’s sizing, all the parameters and assumptions of the choice of the vehicle’s braking system are presented, thus ensuring their reliability, efficiency and safety. Using drawing and simulation software such as SolidWorks and Excel for
Gomes, Lucas OlenskiGrandinetti, Francisco JoséMartins, Marcelo SampaioSouza Soares, Alvaro ManoelReis de Faria Neto, AntônioCastro, Thais SantosAlmeida, Luís Fernando
This study investigates the effects of replacing a 6-speed gearbox with a 5-speed gearbox in a sports vehicle, while keeping all other parameters constant. Through computational simulations, data is collected for comparative performance analysis. The study aims to understand the potential implications of this change on acceleration, fuel efficiency, engine response, as well as aspects such as driver comfort. The results may provide valuable insights for the automotive industry, guiding future transmission design and engineering decisions
Marinho, Gabriel Jannuzzide Campos, Josué QueirozLopes, Elias Dias RossiRodrigues, Gustavo Simão
Gear shift system in a gearbox is used to shift the power flow from one gear set to another gear set which enables manual transmission to maintain different torque and speed combination. Shift quality is determined by the response of the gear shift lever while changing the gears. Shift force over the entire travel event of engagement and disengagement for multiple gear sets is the key factor influencing gear shift quality. If the shift forces are higher, the effort required for shifting will also increase resulting in uncomfortable shifting. On the other hand, with lower shifting force, sudden jerk, vibration or change in vehicle condition may also cause shifting which is undesirable and may lead to safety issue. One of the important features of shift system is auto pull behavior observed while shifting. While shifting, driver starts displacing the shift lever and after threshold point the transmission itself pulls the shift lever to the end point, reducing driver effort. In the
Sabri, Salah AhmadBhimrao, Sachin AhirraoPinto, João PauloMussulini, Bruno CDias, Sebastião Joel
This SAE Recommended Practice describes two-dimensional, 95th percentile truck driver, side view, seated shin-knee contours for both the accelerator operating leg and the clutch operating leg for horizontally adjustable seats (see Figure 1). There is one contour for the clutch shin-knee and one contour for the accelerator shin-knee. There are three locating equations for each curve to accommodate male-to-female ratios of 50:50, 75:25, and 90:10 to 95:5
Truck and Bus Human Factors Committee
The purpose of this SAE Recommended Practice is to establish guidelines for the automatic transmission and hydraulic systems engineer to design rectangular cross section seals for rotating and static grooved shaft applications. Also included are property comparisons of polymeric materials suitable for these applications. Historically, material covered in this document is not intended to include aluminum contact applications
Automatic Transmission and Transaxle Committee
Re-refining of used lubricating oil is an economically attractive and effective recycling method that contributes significantly to resource conservation and environmental protection. The effective re-refining process of used lubricating oil undergoes thorough purification to remove contaminants and to produce high yield and good quality base oil suitable for reuse in lubricant formulation. Used lubricating oils have various hazardous materials, these can be processed with safe and efficient methods required to recover high-quality base oil products. Typically, used lubricating oil is a mixture of various types of additives, base oils, and viscometric grades as per the different types automotive and industrial applications. Re-refined base oils can be re-used to produce lubricants such as industrial and automotive lubricants like passenger car motor oils, transmission fluids, hydraulic oils, and gear oils. API classified base oils into two categories namely mineral base oils API Group I
Maloth, SwamyJoshi, Ratnadeep S.Mishra, Gopal SwaroopSamant, Nagesh N.Bhadhavath, SankerSeth, SaritaBhardwaj, AnilPaul, SubinoyArora, Ajay KumarMaheshwari, Mukul
Gear shifting effort or force especially in manual transmission has been one of the key factors for subjective assessment in passenger vehicle segment. An optimum effort to shift into the gears creates a big difference in overall assessment of the vehicle. The gear shifting effort travels through the transmission shifting system that helps driver to shift between the different available gears as per the torque and speed demand. The shifting system is further divided into two sub-systems. 1. Peripheral system [Gear Shift Lever with knob and shift Cable Assembly] and Shift system inside the transmission [Shift Tower Assembly, Shift Forks, Hub and sleeve Assembly with keys, Gear Cones and Synchronizer Rings etc.] [1]. Both the systems have their own role in overall gear shifting effort. There has been work already done on evaluation of the transmission shifting system as whole for gear shifting effort with typical test bench layouts. Also, work has been on assessment of life of the
Singh, ParamjeetYadav, Sanjay Kumar
Clutch wear is a significant factor affecting vehicle performance and maintenance costs, and understanding its dynamics is crucial for original equipment manufacturers (OEMs) to enhance product reliability and customer satisfaction. It is important to predict clutch wear to enable customers to understand the condition of their clutch and the remaining clutch life, to avoid sudden vehicle breakdowns. This paper explains the approach of measuring the clutch wear profile on an actual vehicle and simulating the same conditions on a powertrain test bench, with the establishment of a correlation in clutch wear profiles
Chopra, ChandanKumar, VarunMamidigumpula, Mohan Kumar Reddy
Cooling system for an IC engine, consisting of the Water pump (WP), Radiator and Fan, plays an important role in maintaining thermal efficiency of the engine and protects the engine from overheating. Based on the vehicle application requirement, Fan will be mounted directly either on Crankshaft or WP pulley. But wherever increase in Fan speed ratio are in demand, it is preferred to mount the Fan on WP pulley. So it important to understand the WP housing structural strength with respect to vibration loads contributed from Radiator Fan assembly. This paper presents investigation of Failure of WP Housing during engine validation at engine test bed with Electronic Viscous Fan, based on the different operating conditions of the engine and fan as per the validation cycle. While the accessories are loading and the corresponding stresses are high when the fan is engaged. But in the current case, the failure of WP housing happened only during Fan clutch disengaged condition. Experimental
R, Mahesh Bharathi
Gear shifting performance in vehicles is critical for smooth operation, especially under cold environment conditions or sub-zero conditions. In this comprehensive study, we delve into the multifaceted aspects that influence gear shifting behaviour during cold conditions especially after overnight vehicle soaking at low temperature below -8°C to simulate real world scenarios. Notably, our efforts on these bench trials focuses on isolating the synchronization load from the maximum block release force, a phenomenon arising from the interaction between synchronizer rings and gear cones in case of high drag of input and counter shafts. Our experimental trials involved multiple bench level testing for lower gear shifting case especially 2nd to 1st gear and 1st to 2nd gear shifting. Factors under study are focusing on changing the Oil (viscosity and quantity), different combination of synchronizer ring material, change of inertia etc. Shifting load in cold condition mainly includes two loads
Mishra, SubodhSiddharth, KumarSingh, Manoj
The stiffness and positioning of engine mounts are crucial in determining the powertrain rigid body modes and kinetic energy distribution. Therefore, optimizing these mounts is essential in the automotive industry to separate the torque roll axis (TRA) and minimize vibration. This study aims to enhance mount locations by isolating the engine rigid body modes and predicting the inter-component force (ICF) and transfer function of the vehicle. The individual ICFs for engine mountings are calculated by applying a unit force at the bearing location. Critical frequencies are identified where the amplification exceeds the unit force at the mounting interface between the engine and the frame. The transfer function approach is utilized to assess the vibration at the handlebar. Both ICF and transfer functions analyze the source and path characteristics linked to critical response frequencies. This understanding aids in enhancing mounting positions to minimize vibration levels, thereby enhancing
Jha, Niraj KumarYeezaku, Antony NeominVictor, Priyanka EstherKrishnamurthy, Govindasamy
In manual transmission, bearing preload is a vital factor for optimum durability and performance of tapered roller bearings (TRB). To achieve better optimization of bearing preload, a precise measurement method is a minimum requisite. This technical paper investigates multiple ideas and develops a novel methodology for accurate bearing preload measurement, overcoming the challenges produced by the complexity of transmission design. This paper provides a systematic approach to bearing preload measurement in manual transmission along with identification of key parameters responsible for influencing bearing preload, such as rigidity and fit of the components. A comprehensive experimental study at both part level and system level was conducted to quantify the effects of above-mentioned parameters on preload and transmission performance. Furthermore, the paper explores the effect of bearing preload optimization on the durability performance of the transmission unit
Gaurav, KumarKumar, ArunSingh, Maninder PalDhawan, SoumilSingh, KulbirKumar, KrishanSingh, Manvir
Front End Accessory Drive (FEAD) systems are used in automobiles to transfer power from the engine-to-engine accessory components such as the alternator, water pump, etc. using a Belt and Tensioner. The emergence of Mild hybrid technologies has led to the replacement of alternator with Belt-driven Integrated Starter-generator (B-ISG). In conventional configuration of FEAD, the power transfer is in single direction but in mild hybrid engine power transfer is bidirectional: tight and slack side of the Belt changes as per Torque assist or Regeneration mode. The presence of an integrated starter-generator (ISG) in a belt transmission places excessive strain on the FEAD System and necessitates checking the dynamic performance of FEAD System thoroughly. Study of Increase in Engine Torque in existing Vehicle was done to understand its effect on various system. This vehicle is Mild Hybrid and consists of Belt-driven Integrated Starter generator system. Increase in Engine torque lead to
Kumar, AdityaGupta, AvinashBharti, Anil Kant
The future of wireless technology - from charging devices to boosting communication signals - relies on the antennas that transmit electromagnetic waves becoming increasingly versatile, durable and easy to manufacture. Researchers at Drexel University and the University of British Columbia believe kirigami, the ancient Japanese art of cutting and folding paper to create intricate three-dimensional designs, could provide a model for manufacturing the next generation of antennas. Recently published in the journal Nature Communications, research from the Drexel-UBC team showed how kirigami - a variation of origami - can transform a single sheet of acetate coated with conductive MXene ink into a flexible 3D microwave antenna whose transmission frequency can be adjusted simply by pulling or squeezing to slightly shift its shape
ABSTRACT The paper presents the fuel economy and performance capabilities of a switchable P2/P3 Hybrid Transmission for commercial and military use cases through modeling and simulation. An overview of the simulation model developed to analyze the vehicle performance and fuel consumption for a specified drive cycle is presented. The model includes the key components of the electrified powertrain including engine, hybrid transmission, electric motor and battery. Use cases were identified to represent Commercial vocational applications and military analogues. The results of P2/P3 Hybrid Powertrain model simulation are compared with that obtained from a model of baseline Conventional Torque Converter Automatic Transmission (AT). The comparison is made for both vehicle performance and fuel economy, and the results indicate that the P2/P3 Hybrid Transmission demonstrates better fuel economy with same or better performance than the baseline heavy-duty automatic transmission. Opportunities to
Patil, ChinmayaThanom, WittDykes, ErikKreucher, JoshGenise, Thomas
ABSTRACT Fuel economy improvements were investigated for the FMTV platform considering alternative transmissions and final drive ratio. An FMTV-M1078 with Caterpillar C7 engine and Allison 3700SP transmission was the target vehicle of this study. Experimental data were collected while vehicle was operated over the FTP72 test cycle. Base vehicle data (vehicle weight, coast-down times, etc.) were collected to provide comparison data for establishing the baseline analytical vehicle model. Experimental data were processed to determine road load parameters, engine BSFC map, transmission shift schedule and similar for populating the analytical model. Modeling was performed using GT-Drive. The model was analyzed over the same defined drive cycle used to collect the experimental data. Once the model was correlated to the experimental data, updates were made for the variants in transmission and drive-line parameters to be used in the fuel economy study. The difference between experimental
Van Benschoten, MattNelson, Evan
ABSTRACT Traditional engineering concerns such as lubrication and cooling are still present even as vehicle functions become more complex. The established solution to monitor fluid levels has been a sight glass or a dipstick. More complex machines demand continuous knowledge of fluid levels without adding to operator workload. Remote monitoring of vehicle health will become normal and expected by owners and operators of evolving vehicle designs. This dual function fluid level sensor provides both electronic and operator monitoring of vehicle fluids, as well as redundancy in the event of electronic failure. Grouping of sensor components that are considered more likely to fail into one group, aids replacement when necessary. By incorporating a traditional dipstick into a continuous electronic monitoring solution, either method of level monitoring is facilitated
Swenson, David
ABSTRACT The HMPT500-3 is a split torque path hydrostatic / mechanical CVT used in the Bradley Fighting Vehicle. A previous paper detailed a linear algebraic approach to model forward operation of the HMPT500-3 without steering using a reduced equation set. This model was expanded to the full equation set to allow transmission operation with steering. The equations showed that opposite to a typical automotive “open” differential, the HMPT500-3 enforces a speed difference between the sprockets for steering, but does not have an inherent torque bias. The typical regenerative steering torque from the decelerated inside track must be provided by interfacing with a vehicle model. A simplified 2-D planar dynamics model of the Bradley was developed to explore vehicle performance and fuel consumption with steering. The integrated model showed that fuel consumption during minimum radius turns can double that of straight-ahead operation at the same speed. Commercial vehicle performance codes
McGough, Matthew G
ABSTRACT Variable displacement pumps have been used in automotive transmissions for decades. L3T had high confidence that a Variable Displacement Oil (VDO) pump would increase overall transmission efficiency. An off-the-shelf (OTS) or OTS modified pump in this pressure and flow range was not found. Therefore, a VDO pump is being developed with the known risk of replacing a highly reliable pump with a new better performing pump of unknown reliability. In this document the development of this VDO pump is discussed. Initial testing of the VDO pump demonstrated an average 25HP savings in pumping losses throughout the transmission operating ranges. At this point, durability testing has not been performed
Bol, Stephen
ABSTRACT The objective of Ker-Train Research Inc.’s 850hp, Gemini III transmission development program is to demonstrate leap ahead transmission technology utilizing a fully geared, highly efficient (>90%) 32-Speed Binary Logic transmission design which has unrivaled power density
Marquardt, BrentBrown, Michael
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