Browse Topic: Splines
As environmental concerns have taken the spotlight, electrified powertrains are rapidly being integrated into vehicles across various brands, boosting their market share. With the increasing adoption of electric vehicles, market demands are growing, and competition is intensifying. This trend has led to stricter standards for noise and vibration as well. To meet these requirements, it is necessary to not only address the inherent noise and vibration sources in electric powertrains, primarily from motors and gearboxes, but also to analyze the impact of the spline power transmission structure on system vibration and noise. Especially crucial is the consideration of manufacturing discrepancies, such as pitch errors in splines, which various studies have highlighted as contributors to noise and vibration in electric powertrains. This paper focuses on comparing and analyzing the influence of spline pitch errors on two layout configurations of motor and gearbox spline coupling structures
As part of the development of its new powertrain consisting of two electric motors, a combustion engine and a gearbox, Renault SAS followed an original approach to achieve an assembly with an optimized, robust, and reliable link between the main electric motor and the gearbox. The running operation optimization as well as the high reliability is achieved by processing the following topics: filtration of vibrations and operating jolts; solving of tribological problems specific to splined connections, such as fretting corrosion and abrasive tooth wear; avoidance of potential seizure of elements with cyclic relative slippage under load; and eventually, control of wear and tear on the sealing and damping O-rings, which must accept oscillating translational movements at the same time as torque transfer. The aim of this article is to retrace the main steps taken to achieve the desired reliability and performance targets for this type of product. The most remarkable points of this approach
In the present amplifying automobile industry, the usage of modern manufacturing technology for splines has been enhanced extensively in conjunction with the conventional manufacturing process. Axial Forming process is specifically a cold bulk deforming technology for metals that is adequate for manufacturing of the High quality internal/external splines. The Aim of this paper is to study and optimize the process parameters of axial forming process to improve the Overall process performance. Axial Forming process characteristics like forming forces, surface quality, Spline Forming efficiency and Stress-Strain behavior are considered as prima facie to elaborate the process performance. Axial Forming Process is mathematically has to be modelled for Spline with Base Material- 42CrMo4 steel with feed speed in aforesaid encapsulated manufacturing process. The optimum value range of the process parameters helps in achieving the comprehensive optimum effect of small forming force, high
As the main power form of new energy vehicles, e-axle systems are has been widely used in passenger vehicles and commercial vehicles. A passenger car equipped with an e-axle, in constant speed and low torque conditions, there is a noticeable rattle noise, through experimental investigation and comparative analysis, it is confirmed that the connection spline of motor and reducer is the main influencing factor. Then, Through the qualitative analysis of simulation, it is found that both spline clearance and misalignment have an amplification effect on the motor speed, thereby stimulating the gear pair of the reducer to produce rattle. The amplification effect of spline clearance is stronger than that of spline misalignment. Therefore, improving the stiffness and application amount of lubricating grease while controlling the spline sample to meet the design requirements can effectively solve the problem of rattle, improve the accuracy of spline alignment, and significantly reduce the
The Tractors are inevitable in the world due to its remarkable contribution majorly in farming process and other applications. the farming equipment needs to perform multiple applications to enhance the productivity and increased horsepower demands all-wheel drive (Refer fig. 1) or four-wheel drive option in the tractor. So, it is becoming a mandatory feature. The main objective of this study is, improving the torsional fatigue life in front axle spindle shaft by modifying the spline design and optimizing induction hardening heat treatment process in such a way that the other part of the system will have a minor or no design change. It helps us to reduce the part count variability, lower manufacturing cost and development time. The spindle shaft with undercut design and profile modified design were subjected to tortional fatigue test with same loading conditions to understand the fatigue life cycle difference between two designs at the load of 700kgm as per DVP, the current spline
This paper addresses the uncertainty quantification of time-dependent problems excited by random processes represented by Karhunen Loeve (KL) expansion. The latter expresses a random process as a series of terms involving the dominant eigenvalues and eigenfunctions of the process covariance matrix weighted by samples of uncorrelated standard normal random variables. For many engineering appli bn vb nmcations, such as random vibrations, durability or fatigue, a long-time horizon is required for meaningful results. In this case however, a large number of KL terms is needed resulting in a very high computational effort for uncertainty propagation. This paper presents a new approach to generate time trajectories (sample functions) of a random process using KL expansion, if the time horizon (duration) is much larger than the process correlation length. Because the numerical cost of KL expansion increases drastically with the size of time horizon, we partition it into multiple subdomains of
In recent years, research on car-like robots has received more attention due to the rapid development of artificial intelligence from diverse disciplines. As essential parts, path planning and lateral path tracking control are the basis for car-like robots to complete automation tasks. Based on the two-degree-of-freedom vehicle dynamic model, this study profoundly analyzes the car-like robots’ path planning and lateral path tracking control. Three objectives: path length, path smoothness, and path safety, are defined and used to construct a multi-objective path planning model. By introducing an adaptive factor, redefining the selection of reference points, and using the cubic spline interpolation for path determination, an improved NGSA-III is proposed, which is mostly adapted in solving the multi-objective path planning problem. Furthermore, the chattering problem of sliding mode control is eliminated by introducing fuzzy control, and a sliding mode controller with fuzzy control is
In electric-powertrains, noise and vibration can be generated by components such as gears and motors. Often a noise phenomenon known as rumble or droning noise can occur due to low shaft order excitation at the spline. In this study, we identified the excitation source for spline induced rumble noise and developed a novel analysis method. First, a detailed spline model, believed to be the key factor for rumble noise, has been developed and verified by comparison with Finite Element Method(FEM) analysis. In order to identify an excitation source, a typical electric-powertrain assembly model including the developed spline model was constructed and simulated. Results according to changes of key factors including spline pitch errors and shaft alignment errors were analyzed. Spline radial force has been identified as an excitation source of spline induced rumble noise. This was verified through comparison with the forced vibration analysis result and time domain analysis result. This paper
This ARP applies to turbine engines that are to be used in helicopters. It provides the engine designer guide lines in achieving a satisfactory turbine engine drive shaft connection.
High-performance vehicle wheel bearings experience high lateral loading during racetrack testing. Due to higher loads, the wheel bearings are more susceptible to structural and or preload failures. Structural failures can occur in the hub flange, spline and/or roll form. The increased loading and cycling requirements, drives the need to adjust historical evaluation methods. The wheel bearing design for a high-performance vehicle must find the optimum balance between strength, drag, packaging, and mass. The objective of this paper is to cover the methodology to evaluate wheel bearings using the predicted loads before the actual vehicle testing. Initially, the predicted load data consists of many data points and is not suitable for either CAE analysis and/or physical testing. This paper is planned to cover the approach to condense the large number of short duration steps into small number of large duration steps which can be used for CAE and bench test evaluations without changing the
This paper takes a review of fretting phenomenon on splines of the engaging gears and corresponding splines on shaft of automotive transmission and how it leads to failure of other components in the gearbox. Fretting is a special wear process which occurs at the contact area of two mating metal surfaces when subject to minute relative oscillating motion under vibration. In automotive gearbox, which is subjected to torsional vibrations of the powertrain, the splines of engaging gears and corresponding shaft may experience fretting, especially when the subject gear pair is not engaged. The wear debris formed under fretting process when oxidizes becomes very hard and more abrasive than base metal. These oxidized wear particles when comes in mesh contact with nearby components like bearings, gears etc. may damage these parts during operation and eventually lead to failure. In this paper, a case study is presented wherein fretting has been identified as the root cause of failures of some
This specification establishes the requirements for the following types of self-locking nuts: a Wrenching nuts: that is, hex, double hex, spline drive b Anchor nuts: that is, plate nuts, gang channel nuts, shank nuts The wrenching nuts and shank nuts are made of low alloy steels, and the nut elements of plate and gang channel nuts are made of carbon steels or low alloy steels and having MJ threads to ISO 5855/2. Nuts have 1100 MPa tensile strength class at room temperature. Maximum test temperature of parts at 235 °C.
This SAE Standard applies to hydraulic pumps and motors used on off-road self-propelled work machines as described in SAE J1116.
The advancement in embedded systems and positional accuracy with base station GPS modules created opportunity to develop high performance autonomous ground vehicles. However, the development of vehicle model and making accurate state estimations play vital role in reducing the cross track error. The present research focus on developing Linear Quadratic Gaussian (LQG) with Kalman estimator for autonomous ground vehicle to track various routes, that are made with the series of waypoints. The model developed in the LQG controller is a kinematic bicycle model, which mimics 1/5th scale truck. Further, the cubic spline fit has been used to connect the waypoints and generate the continuous desired/target path. The testing and implementation has been done at APS labs, MTU on the mentioned vehicle to study the performance of controller. Python has been used for simulations, controller coding and interfacing the sensors with controller. From the results, it has been confirmed that, the vehicle
This paper presents an optimal cooperative path planning method considering driver’s driving intention for shared control to address target path conflicts during the driver-automation interaction by using the convex optimization technique based on the natural cubic spline. The optimal path criteria (e.g. the optimal curvature, the optimal heading angle) are formulated as quadratic forms using the natural cubic spline, and the initial cooperative path profiles of the cooperative path in the Frenet-based coordinate system are induced by considering the driver’s lane-changing intention recognized by the Support Vector Machine (SVM) method. Then, the optimal cooperative path could be obtained by the convex optimization techniques. The noncooperative game theory is adopted to model the driver-automation interaction in this shared control framework, where the Nash equilibrium solution is derived by the model predictive control (MPC) approach. Finally, the proposed framework is tested with
A real-time obstacle-avoidance trajectory planner for on-road autonomous vehicle is proposed in this paper. A cubic B spline core is parametric to generate path with continuous curvature as well as taking the extreme curvature limited by steer system into account. By sampling the target sets via offsetting along the reference path, lots path sets are produced with same heading. As embedded with collision checker and path evaluator, a path selector could pick out the best one to planning speed profile for coupling trajectory to track. Finally, according to the change of path curvature, the speed profile scheduler addresses the conflict of curvature and deceleration. Referencing to the ISO3888-2:2011, a collision avoidance scenario was design to validate the planner. The test results of ten cycles test illustrate that the planner has high enough real-time performance as mean plan time less than 100ms with success rate about 100%.
This concept for measuring worn splines provides a direct wear depth dimension by utilizing the unworn involute surface as a contact point from which to measure the depth of wear on the spline tooth at the pitch diameter. Fig. 1 shows spline wear patterns and pitch diameter gaging points.
This SAE Recommended Practice covers passive torque biasing axle and center differentials used in passenger car and light truck applications. Differentials are of the bevel gear, helical gear, and planetary types, although other configurations are possible.
This standard covers the design, performance, and test requirements for high strength, thin wall, commercial sockets, universal sockets, and box wrenches used for the attachment and detachment of metric spline drive, high strength, and high temperature aircraft fasteners. Inclusion of dimensional data in this standard is not intended to imply that all of the products described herein are stock production sizes. Consumers are requested to consult with manufacturers concerning lists of stock production sizes. This standard is based on, but not limited to, the following external spline wrenching system:
This study addresses the adequacy of sockets, wrenches, and torque adapters conforming to AS954 to wrench 12 point fasteners with wrenching configurations conforming to AS870C. Reported wrenching problems with smaller sizes are investigated through examining the combined tolerances on the fasteners and wrenches, conducting torque testing on typical high strength lock nuts. Possible solutions to correct these wrenching problems are presented.
To fully define the following requirements for bolts with spline and hexagon heads of strength class up to but not including 1250 MPa: a Head dimensions (see 3.1) b Shank dimensions (see 3.2) c Geometric control (see 3.3) d Surface texture (see 3.4) This document is based on one class of thread after all processing, including coating or plating, has been completed as follows: tolerance class 4h6h. For particulars of thread, see AS1370. For thread runout and lead threads, see AS3062. To fully define the following requirements for nuts with spline, plain hexagon and castellated configurations of strength class up to and including 1100 MPa: a Nut dimensions (see 4.1) b Geometric control (see 4.2) c Surface texture (see 4.3) For particulars of threads, see AS1370. This document is based on the following classes of internal threads after all processing, including coating or plating, has been completed: Tolerance class 4H6H for sizes up to and including 5 mm Tolerance class 4H5H for size 6
This SAE Aerospace Standard (AS) is intended for use by those involved in the design of aircraft, missile, or space systems, and their support equipment to define the various types of fastener torque.
This standard specifies the areas to be used in calculating stress or load values to be used in externally and internally threaded fastener procurement specifications for bolts, screws, nuts, and studs and for the information of designers.
To fully define the following requirements for bolts with spline and hexagon heads of strength class up to but not including 1250 MPa: a Head dimensions (see 3.1) b Shank dimensions (see 3.2) c Geometric control (see 3.3) d Surface texture (see 3.4) This document is based on one class of thread after all processing, including coating or plating, has been completed as follows: tolerance class 4h6h. For particulars of thread, see AS1370. For thread runout and lead threads, see AS3062. To fully define the following requirements for nuts with spline, plain hexagon and castellated configurations of strength class up to and including 1100 MPa: a Nut dimensions (see 4.1) b Geometric control (see 4.2) c Surface texture (see 4.3) For particulars of threads, see AS1370. This document is based on the following classes of internal threads after all processing, including coating or plating, has been completed: Tolerance class 4H6H for sizes up to and including 5 mm Tolerance class 4H5H for size 6
This specification establishes the requirements for self-locking wrenchable nuts with thread sizes 0.7500 thru 1.5000 inches. The nuts are made of corrosion and heat resistant precipitation hardenable iron base alloy of the type identified under the Unified Numbering System as UNS S66286 and of 160,000 psi axial tensile strength at room temperature, with maximum conditioning temperature of parts at 800 °F.
In the emerging commercial vehicle sector, it is very essential to give a product to customer, which is very reliable and less prone to the failures to make the product successful in the market. In order to make it possible, the product is to be validated to replicate the exact field conditions, where it is going to be operated. Lab testing plays a vital role in reproducing the field conditions in order to reduce the lead time in overall product life cycle development process. This paper deals with the design and fabrication of the steering column slip endurance test rig. This rig is capable of generating wear on the steering column splines coating which predominantly leads to failure of steering column. The data acquired from Proving Ground (PG) was analyzed and block cycles were generated with help of data analyzing tools. Those block cycles were run with the help of this rig it consists of Variable Frequency Drive (VFD) to change the velocity of steering column, and torque applied
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