Theoritical analysis of macpherson suspension system ijsart. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. The macpherson strut page 4 of 4 ate up with motor. Figure 17 antiroll bar connection to doublewishbone suspension 54 32. Install the strut in the compressor j340b, then install the compressor adapters, if used.
The mac pherson strut is a type of car suspension system which uses the axis of a telescopic damper as the upper steering pivot. With a macpherson design, the strut is an critical piece in the suspension assembly. Since the strut governs the king pin axis as well as the camber of the tire, these two parameters are linked the adjustability of the macpherson strut is limited, due to its simplicity most adjustability of the suspension is achieved by modifying the location of the upper strut mounting location. Many production cars especially if they have frontdrive use the macpherson strut suspension. The piston rod, which is strengthened from 11 mm to 18 mm up to 25 mm diameter on passenger cars and up to 28 mm on light commercial vehicles, can absorb longitudinal and lateral forces and replaces the upper suspension link, including its three mountings. Common problems with macpherson struts and how to make them. Macpherson struts and coil springs repair guide autozone. Within those books, an assumption was made that the roll center of a suspension system was fixed along a vertical axis. However depending on how it is set up they can be effective.
Foamed oil reduces the dampening capacity and results in. The system was invented in 1955 and used on the first ford consul. The macpherson strut and spring are under extreme pressure. Synthesis lectures on advances in automotive technology. Free the damper from the strut by unfastening the large gland nut between its two telescopic sections. Check the threads on the strut tube for damage, and clean them. The history of the macpherson strut can be traced back to an earlier system that was originally used by fiat.
The macpherson strut is a further development of the double wishbone suspension. There are myriad irs systems, including swing arm, macpherson strut, trailing arm, semitrailing arm, harm, double aarmsla, fivelink, and so on. It is widely used in the front suspension of modern vehicles and is named for american automotive engineer earle s. Common problems with macpherson struts and how to make. Substituting a new side load spring with curved centerline for the conventional coil spring has been proven able to solve these problems and multibody dynamics combining. Macpherson strut suspension is a simple independent suspension design used by just about every mainstream car maker in the world, normally for front wheels. The purpose of this book is to cover essential aspects of vehicle suspension.
Macpherson suspension strut this is the most widely used front suspension system today, but most especially by european brands. Vehicle suspension system technology and design amir khajepour and avesta goodarzi. However, there is also a modified macpherson strut design. Mount the compressor tool j340b in the holder j328920. Why is a macpherson strut used as a front suspension in most. Novel was the original macpherson coil spring over shock absorber strut that sat in a tower just like todays and the fact that the 3speed transmission sat under the front seat and utilized. There are several moving parts to the front strut suspension and, as its subjected to a relatively hard life, failures do occur. Drag race use only for hub mount wheelschoice of 4 12. Techtips replacing and upgrading macpherson struts and. Geometric design of independent suspension linkages deep blue. It is widely used in modern vehicles and named after earle s. For doublewishbone or unequal length aarm types, the camber change created by lowering can be reduced. Macpherson suspension system contains upper mounting point, shock absorber, spring, spring leaf and lower control arm.
The design uses a lower aarm and the springshock absorber. The double wishbone suspension provides the engineer more design choices than some other types do. Macpherson strut front suspension system design skedsoft. If lowering your vehicle, the suspension geometry should be considered. Most modern cars use macpherson struts in their front suspension and some in the rear as well for their simplicity and predictable handling. Just because a car has double wishbone suspension doesnt mean its going to be good round corners. Substituting a new side load spring with curved centerline for the conventional coil spring has been proven able to solve these problems and multibody dynamics. Both parallel arm and macpherson strut systems are independent suspensions. Jan 29, 2018 suspension geometry part 1 camber, toe, caster, kpi, scrub radius. Suspension ppt suspension vehicle steering free 30.
In the 1970s, general motors published a book, which included information on suspension design and dynamics. Macpherson of general motors in 1947, is the most widely used front suspension system, especially in cars of european origin. In this setup, the front wheels are allowed to move independently. Suspension geometry part 1 camber, toe, caster, kpi, scrub. This system, which dates to the 1920s, and another similar leaf springbased design that was employed by french automaker cottindesgouttes, are early examples of designs that unified the steering pivot and suspension into a single component. These incorporated the first macpherson strut independent suspension both in front and rear. The macpherson strut is a type of automotive suspension system that uses the top of a telescopic damper as the upper steering pivot.
Mcpherson suspension geometry tentenths motorsport forum. It also provides least camber change at bump and rebound condition. Design characteristics of mcpherson suspensions 973067 the macpherson strut is an excellent solution for front wheel drive suspensions that has been used worldwide by car manufacturers. The macpherson strut is a type of car suspension system commonly used in many modern motor vehicles. Suspension geometry part 2 roll center, double wishbone, macpherson strut.
Topology based optimization of suspension and steering. For macpherson strut types, the camber change may be too negative to provide a proper contact patch from the tire. Undesired lateral force inevitably exists in a macpherson suspension system, which is liable to damper rods side wear and promotes the dampers inner friction decreasing the ride performance from the suspension system. If you do not have a spanner that fits the nut, put it in the vice and turn the strut. Optimized design for a macpherson strut suspension with side. Front suspension systems introduction, suspension system components, shortandlong arm front suspension systems, macpherson strut front suspension system design, modified macpherson strut suspension, high performance front suspension systems, torsion bar suspension, curb riding height, front spring sag curb riding height and caster angle. I this video you will find everything you need to know about front suspension. Suspension geometry part 1 camber, toe, caster, kpi, scrub radius.
All bmw 1234series models use a macpherson front strut. If the nut is rusty, penetrating oil will help to free it. Macpherson strut suspension written by editor on 20140616, posted in car chat, technical talk 0 comments now lets take a look at the third type of automobile suspension. The macpherson strut combines a shock absorber and a coil spring into a single. A macpherson strut consists of a piston connected to a rod in a tube of oil. Our sources on the life of earle macpherson, the origins of the chevrolet cadet, and the origins of the macpherson strut suspension included herb adams, chassis engineering hp1055 new york. A series of valves control the oil flow to control the pitching and rebound in the suspension system. There are many flavours of double wishbone suspension, some good and some bad.
Depending on the type of racing for race cars, the road surface and evolution of the vehicles, the suspension is designed to accommodate multiple requirements. Explain the construction and working of macpherson strut. Jul 08, 2019 novel was the original macpherson coil spring over shock absorber strut that sat in a tower just like todays and the fact that the 3speed transmission sat under the front seat and utilized. The piston rod, which is strengthened from 11 mm to 18 mm up to 25 mm diameter on passenger cars and up to 28 mm on light commercial vehicles, can absorb longitudinal and lateral forces and replaces. Aluminum strut package, stud mount externally adjustable, heavy duty brake kit for hub mount wheels. Pdf kinematic and dynamic analysis for a new macpherson strut. Assembling the pieces with the proper geometry was essential to. Macpherson struts are the most important element of the suspension system in many modern vehicles, and should be replaced, on average, every 50, 000 to 80.
Lightweight macpherson strut suspension front lower control. What is macpherson strut suspension and why is it so popular. By 1946 three prototypes of the cadet design had been produced. Likewise even a car with a good design of double wishbone suspension wont necessarily be faster than a welldesigned macpherson strut set up. Oct 11, 2019 macpherson suspension strut this is the most widely used front suspension system today, but most especially by european brands. This includes both front and rear suspensions, but usually located at the front of the car. In the modified design, the coil spring is separate from the strut assembly. The mcpherson strut also carries and controls the wheel. A hydraulic dampening system is subject to foaming due to heat helping air to mix with the oil in the tube. Lightweight macpherson strut suspension front lower control arm design development 2011010562 the paper will discuss the results of a study to develop lightweight steel proofofconcept front lower control arm flca designs that are less expensive and achieve equivalent structural performance relative to a baseline forged aluminum flca assembly. This was the basis for several books on racecar suspensions in the years following its publication. This tool is very limited to the number of strut springs it will work with.
Similar to other suspension systems, irs has gone through a long designdevelopment process and not all of the designs are created equal. The type of suspension macpherson strut or double wishbone suspension. The macpherson suspension is a technology for front and rear suspension. Camber matters optimizing track performance for strut. Besides the advantages of this suspension it presents many difficulties due to the characteristic of being a bending structure. The mcpherson strut is a very popular mechanism for. The macpherson strut version of the original suspension calculator with the same easy to use drag and drop interface. Vehicle suspension system technology and design morgan. In macpherson strut type suspension system,only lower wishbone are used. The designs, which are known today as mcpherson struts, are divided into two groups. Macpherson strut is used in most cars because of its simplicity and advantages in placement for compact cars and it is commonly used for passenger cars. Never remove the center strut nut without first installing an approved macpherson strut spring compressor.
It is best described as a shock absorber built inside a coil spring to function as a single cohesive unit. This type of independent suspension got its name from earle s. However, in most vehicle dynamics textbooks, toe angle plays a significant role in the stability of. For the front suspension the following need to be considered. Severe personal injury may result if this procedure is not followed correctly. A macpherson strut compressor tool j340b or the equivalent must be used. Nov 11, 2011 however, there is also a modified macpherson strut design. It is an independent suspension type, including a single suspension arm spring and damper, an antiroll bar and a lower arm. Although a mcpherson strut maybe not the best design for ultimate road holding it is at least simple and easy to replace. Most problems with positive camber arise because the suspension has been lowered past the fulcrum change of the lower arm and the inner mounting should be fitted. The main advantage of the the macpherson is that all the parts providing the suspension and the wheel control can be combined into the one assembly.
Also supports iso 8855 and sae j670e coordinate formats. Mar 25, 2017 i this video you will find everything you need to know about front suspension. Suspension tools free delivery possible on eligible purchases. Working with suspension parts is dangerous, so if youre accident prone, perpetually drunk, or have never heard of a macpherson strut, dont try to do this job yourself. Steering error optimization of the macpherson strut. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray.
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