In-wheel clutches as axle torque differential compensators

Abstract

Vehicles have long faced the problem of wheel speed differences between the two sides of the vehicle, especially when facing winding roads, and in this regard, various inventions and methods have been presented in the field of dealing with the problems arising from it. These methods are usually accompanied by limitations. In the present invention, the connection point of the drive axle with the wheels is designed in such a way that it creates a disconnectable connection based on friction. This connection is designed in such a way that it can transfer the torques applied for normal vehicle movement in different road conditions from the drive axle to the wheels, but when faced with the double torque applied when the vehicle passes through curves, it loses its resistance and allows the drive axle to move freely at its connection to the wheel, preventing problems caused by the application of this double torque.

Description

Description of the invention Title of the invention (as stated in the declaration) In-wheel clutches as axle torque differential compensators in wheel clutches as axle torque difference compensators Technical background of the relevant invention Vehicles are among the oldest and most important inventions of mankind, which have been at the forefront of the technologies of their time from very distant times until now, and in a way, vehicles can be considered a selection of all human technologies. Vehicles have been progressing and evolving since their initial invention, which was in the simplest possible form, and it can be predicted that this evolution will continue indefinitely and vehicles will become more advanced every day and every year. In the present invention, which is a small step in the field of progress and evolution of vehicles, an attempt has been made to solve a small part of the problems that some vehicles face. Technical problem and stating the objectives of the invention Vehicles with more than two wheels (three-wheelers, four-wheelers, and vehicles with more wheels) have always faced the problem of the difference in the speed of rotation of the wheels on both sides of the vehicle. This problem arises in some road conditions, the most acute of which is when encountering curves in the road. When a vehicle passes through a curved road, the wheels located on the center side of the curve move at a lower speed than the wheels located on the outside of the curve. This speed difference causes a difference in the torque applied to the two sides of the vehicle's drive axle, which can cause problems. These problems include 1- creating problems in the movement of the vehicle by disrupting its balance 2- creating serious technical defects in the mechanical parts of the vehicle. In order to solve this problem, several solutions have been proposed, each of which has solved this problem in some way, but most of them are accompanied by problems and sometimes create new restrictions for the vehicles.Among the most important problems caused by these proposed solutions are: 1- increasing the production cost and mechanical complexity of the vehicle and 2- creating problems when the vehicle encounters rough surfaces. In this way, most current vehicles, when the wheels of one side are placed on a rough surface, transfer all the power produced by the engine to that wheel and the vehicle loses its ability to move. Despite its mechanical simplicity, the present invention reduces the cost and also shows acceptable performance when encountering rough surfaces. A description of the state of the prior art and the history of developments related to the claimed invention. Vehicles have long faced the problem of wheel speed differences between the two sides of the vehicle, especially when facing winding roads, and in this regard, various inventions and methods have been proposed to deal with the problems caused by it. In general, the methods proposed to solve these problems can be placed in the following three general categories: 1- Using a rigid axle system 2- Fixing the problem using the geometry of the wheel and axle assembly 3- Use of different types of differentials The following is a description and explanation of how each of the above works, as well as the history of each of the above. Rigid axle system This system is the simplest system that can be designed for the final part of the power transmission system, which has been used since the invention of the first vehicles, and in which the power generated by the engine, after passing through systems such as the clutch and gearbox system, is transferred directly to the drive axle and directly to the wheels of the vehicle. In this system, which can be considered as a solution to the problems mentioned in the previous section, the set of wheels and the drive axle act as a rigid piece and the wheels on both sides of the vehicle rotate at the same speed in all road conditions. In this system, the strength of the mechanical parts is considered as high as possible to prevent mechanical problems as much as possible, but most of the problems mentioned remain unsolved. In such vehicles, when passing through curves, the wheel that is located on the center side of the curve starts to spin and the wheel that is located on the outside side of the curve starts to drag on the road, and thus, the curve is passed.It is clear that this performance is associated with a lot of wear and tear on the vehicle's tires as well as its other mechanical parts. The advantages of this system include the following: 1- Low mechanical complexity 2- No problem in dealing with rough surfaces 3- Low cost The disadvantages of this system include the following: 1- Inefficiency in compensating for the torque difference between the wheels on both sides of the vehicle 2- Causing problems in the movement of the vehicle and disrupting its dynamic balance. 3- Causes wear and tear on various parts of the vehicle, including the drive axle, the connection point between the drive axle and the wheels, the wheel rims, the tires, the bearings connecting the drive axle to the body, etc. Current applications of this system include the following: 1- Light vehicles, especially recreational vehicles such as three-wheeled and four-wheeled motorcycles, go-karts, drift trikes, etc. 2- Toys like most small-sized control cars 3- Some agricultural equipment such as tillers, harvesters, etc. Wheel and axle assembly geometry Among the systems available to address the problems mentioned in the previous section is the use of wheel and axle geometry for this purpose. Perhaps the most important example of this system can be seen in the wheels and axles of rail vehicles. The history of this system can be attributed to the emergence of rail vehicles. In this system, the vehicle's wheel and axle assembly is one piece and rigid, and the wheel geometry is designed to compensate for the speed difference between the two sides of the axle when passing through winding paths. In this system, the wheels of the vehicle that move on rail tracks are designed in the shape of an incomplete cone. These wheels, which are designed in one piece with their connecting axle, have a small amount of movement in the distance between the two rails, which allows the wheel and axle assembly to move laterally. When passing through turns, due to centrifugal force and the conical geometry of the wheels, the wheel and axle assembly is moved outward from the center of the turn, causing the wheel located on the center side of the turn to have a smaller diameter and the wheel located on the outside of the turn to have a larger diameter. In this way, the wheels on both sides of the vehicle travel different distances despite the same rotational speed, and thus there is no difference in the torque on the two sides of the drive axle. The advantages of this system include the following: 1- Lack of mechanical complexity 2- Low total cost Among the disadvantages of this system are the following: 1- Exclusive use in rail vehicles 2- The need to use rail lines and metal wheels Among the applications of this system are its use in various rail systems as well as in some new robotic vehicles. Differentials The use of differentials can be considered the most intelligent action of mankind in facing the problems presented in the previous section. Although this action has brought new limitations and problems, it has been widely used and has been accompanied by progress and evolution day by day. The history of this system and its types will be discussed below. There are various views on the invention of the differential. Some historical milestones for the differential include: 70-100 BC: The Antikythera mechanism dates back to this period. Scientists discovered the mechanism in 1902 in the wreckage of a shipwreck, and new research suggests that it used a type of differential to determine the angle between the ecliptic positions of the sun and moon, and thus the position of the moon. 227–239 AD: Ma Jun of the Wei Dynasty in China invented the first historical south-facing chariot. This south-facing chariot used a non-magnetic compass mechanism as well as a type of differential. 658-666 AD: Two Chinese engineers and Buddhist monks built south-facing chariots for Tenji, the then Emperor of Japan, which used a type of differential. 1027–1107 AD: Reproduction of the south-facing chariot by Yan Su and then Wu Deren, which described details of the mechanical operation and gear ratios of the device far more detailed than any other known in China. 1720: Joseph Williamson used a differential in a watch. 1810: German Rudolf Ackermann used a four-wheel steering system for carriages, which some later mistakenly reported as a differential. 1827: The current differential, used in contemporary automobiles, was first invented by Oncifou Picouer, a French watchmaker, for use in a steam engine. 1832: Richard Roberts invented a device called the compensating gear, which was used as a differential in road locomotives. 1874: Owing and Porter used a Rochester type differential for the rear axle in a locomotive. 1876: James Starley designed a differential for use in bicycles, an invention later used in automobiles by Karl Benz. 1897: David Shearer in Australia first used a differential in a steam engine. 1958: Vernon Gleizman invented the Torsen differential. This was a type of limited-slip differential that relied solely on gears instead of a clutch and gear combination. Definition of differential In general, a differential can be defined as a system whose main function is to transfer torque generated by a vehicle's engine to its wheels. The differential receives the power generated by the engine, divides it between the right and left wheels of the vehicle, and simultaneously allows each wheel to move at different speeds. When passing through a curve on the road, the wheel on the outside of the curve travels a greater distance than the wheel on the inside of the curve, and therefore must rotate at a higher speed. In the meantime, the differential plays a fundamental role by being located in the path of transmitting engine power to the wheels and by creating a balance between the wheels on both sides of the vehicle, it allows it to pass through curves on the road. Differentials are divided into several main types, which are listed below: 1- Open differential 2- Locking differential 3- Limited slip differential (types of clutch, viscous coupling and Torsen) 4- Welded differential 5- Active differential 6- Torque distribution differential 7- Differentials with non-rotating gears As mentioned in the previous sections, the main function of a differential system is to balance the force distributed between the wheels on both sides of a vehicle, and this function is achieved by the gear-shifting mechanism. Despite its high efficiency, this function also comes with limitations that make its use in some vehicles difficult. The advantages of using differentials include the following: 1- Fully effective compensation of torque difference between the two sides of the vehicle's drive axle 2- Ability to run on most vehicles 3- Ability to transmit high torques The disadvantages of using differentials include the following: 1- Lack of proper performance when dealing with rough surfaces, especially in cases where the friction of the wheels on one side of the vehicle with the ground is very different from that on the opposite side. 2- High mechanical complexity (especially for new systems and anti-slip systems) 3- High manufacturing costs, which increase the total cost of the vehicle. Some of the uses of differential-based systems include the following. 1- Types of light and heavy vehicles 2- Professional sports vehicles 3- Professional control toys Providing a solution to an existing technical problem along with an accurate, sufficient, and integrated description of the invention The present invention, by presenting a different perspective than other solutions presented, focuses its attention on the connection of a vehicle's wheels to its drive axle and uses a fundamental point, which is mentioned below. The fundamental point in the problem of torque differentials on both sides of the vehicle drive axle, which is the main cause of the problems mentioned in the previous sections, is that in a typical vehicle with a rigid drive axle, when the vehicle is going around a curve on a road, the wheels of this vehicle are subjected to an additional torque that can be significantly greater than the torque applied to the wheels by the power transmitted to them by the engine. This additional torque can cause mechanical defects in the axle and wheel assembly, including breakage at the connection point between the drive axle and the wheels. In the present invention, the connection point of the drive axle to the wheels is designed to create a friction-based disconnectable connection. This connection is designed to transfer the torques applied for normal vehicle movement in various road conditions from the drive axle to the wheels, but when faced with the additional torque applied when the vehicle passes through curves, it loses its resistance and allows the drive axle to move freely at its connection point to the wheel, preventing the problems presented in the previous sections. In this invention, the connection of the drive shaft (1) to the wheels of the vehicle (6) is provided with a set consisting of one or two friction plates (4 and 8) and friction pads (5 and 7), which makes this connection a disconnectable connection. The mechanical connection of the drive shaft to the wheels is provided by the friction between the friction plates and the friction pads. It is worth noting that the amount of this friction must be adjusted according to the size of the vehicle and the amount of torque produced by it. This amount of friction can be adjusted by increasing or decreasing the contact area of ​​the discs and friction pads, as well as the amount of spring force used. The advantages of using this system include the following: 1- Effective compensation of torque difference between the two sides of the vehicle's drive axle 2- Fixing the problem of inefficiency in encountering rough surfaces even in cases where one side of the vehicle is on rough surfaces. In such a case, this system operates almost similarly to a rigid axle system and transfers engine power equally to the wheels on both sides of the vehicle, allowing for smooth movement in such conditions. 3- Low mechanical complexity 4-Low manufacturing cost and reduced vehicle cost Among the shortcomings of this system are the following: 1- Since the connection between the drive axle and the wheels in this system relies solely on friction, this system is not capable of transmitting high torques (used in heavy vehicles) and can only be used in light vehicles, sports vehicles, medical assistance vehicles, etc. Explanation of shapes, maps and diagrams Part 1: Main drive shaft Part 2: Spring retaining plate Part 3: Spring Part 4: Inner friction plate Part 5: Inner friction pad Part 6: Rim and tire set Part 7: External friction lining Part 8: External friction plate with retaining tube A clear and precise statement of the advantages of the claimed invention over prior inventions. -Effective performance in dealing with various road conditions -The mechanical simplicity of the present invention compared to existing complex designs -Easier and cheaper to manufacture than existing designs -Less possibility of technical errors due to simplicity of design Description of at least one implementation method for implementing the invention This invention can be implemented and used in the power transmission system of all types of light vehicles. Explicit mention of the industrial application of the invention The present invention is used in the transportation industry and in the production of various light vehicles, including sports vehicles such as three-wheeled and four-wheeled motorcycles, medical aids such as wheelchairs and scooters, as well as light personal cars. Brief description of the invention Vehicles have long faced the problem of wheel speed differences between the two sides of the vehicle, especially when facing winding roads, and in this regard, various inventions and methods have been presented in the field of facing the problems caused by it. These methods are usually accompanied by limitations. In the present invention, the connection point of the drive axle with the wheels is designed in such a way that it creates a friction-based disconnectable connection. This connection is designed in such a way that it can transfer the torques applied for normal movement of the vehicle in different road conditions from the drive axle to the wheels, but in the face of the double torque applied when the vehicle passes through the bends of the roads, it loses its resistance and allows the drive axle to move loosely at its connection to the wheel, preventing the occurrence of problems caused by the application of this double torque.

Claims

Claim What is claimed: Claim 1) Design of in-wheel clutches as axle torque difference compensators that create a disconnectable connection with a friction mechanism at the point where the wheels connect to the vehicle's drive axle and give the axle and wheel assembly the ability to absorb the additional torque applied to the wheels when the vehicle passes through curves and prevent problems with the vehicle's balance and mechanical defects. This mechanism also distributes the force generated by the engine equally between the wheels on both sides of the vehicle when the vehicle encounters slippery surfaces and prevents the wheel that has the highest slip from slipping. This system consists of the following main parts: -Rim and tire assembly -Friction plate assembly -Spring Claim 2) Based on claim (1), the rim and tire assembly forms the central part of the system and itself acts as the central friction surface. Claim 3) According to claim (1), friction plates comprising metal friction plates and friction pads are located on one or both sides of the rim and tire assembly and are mechanically connected to the drive axle of the vehicle. By changing the size of these friction plates, the amount of friction can be adjusted for vehicles of different power. Claim 4) Based on claim (1), the spring is another essential part of this system that applies the necessary pressure to the friction plates and pads and causes friction between them. By changing the compressive force of the spring, the amount of friction can be adjusted for vehicles with different powers.