A torsion spring assembly for a wheel suspension of a motor vehicle, including two torsion bars arranged coaxially one inside another and also a spring element, which is arranged axially-parallel to the two coaxial torsion bars, and can be mounted on the motor vehicle body via a bearing position, wherein the radial outer hollow-cylindrical torsion bar can be mounted on the motor vehicle body side and is connected in a rotationally-fixed manner to an output lever fastenable on a wheel guiding element and the radial inner torsion bar is connected in a rotationally-fixed manner to the outer torsion bar and is connected in a rotationally-fixed manner via a coupling to the spring element.

An elastic member is an elastic member formed of a wire having a cross section that is substantially circular, the cross section being orthogonal to a longitudinal direction, and the elastic member being expandable and contractible in a predetermined direction; and including: a first alloy portion that is made of an aluminum alloy having a tensile strength larger than 950 MPa and equal to or less than 1100 MPa at room temperature; and a second alloy portion configured to cover the first alloy portion, the second alloy portion having a thickness in a radial direction smaller than a radius of the first alloy portion, and being made of an aluminum alloy having a tensile strength of 100 MPa to 650 MPa at room temperature.

A trailer for towing by a power vehicle is provided and generally includes a frame and a tandem wheel assembly. The frame forms an undercarriage chassis and the tandem wheel assembly positioned under the undercarriage chassis. The tandem wheel assembly includes a rear wheel assembly and a front wheel assembly. An extension assembly is provided and moves the front wheel assembly between trailing position and a self-propelled position where the rear wheel assembly and the front wheel assembly are positioned to equally support the undercarriage chassis.

An axle cartridge member receives a pair of torsion stub axles at opposite lateral sides thereof. The torsion stub axles include elongated axle housings, which are sandwiched between two parallel plates to align the torsion stub axles with respect to one another. The cartridge member includes a central arch extending between the two torsion stub axles, which can provide additional ground clearance when the axle cartridge member is mounted to a trailer.

A removable spindle axle improvement using a cap attached to a rim formed along an inside surface of a torsion arm, wherein the cap seals a threaded fastener. The rim used for attachment can be a groove, collar, or a collared washer. In an alternative embodiment, a first O-ring is positioned along an end of a spindle axle tapered body and a second O-ring groove is positioned along an opposite end of the spindle axle tapered body to hermetically seal an area of the spindle axle therebetween. In a further embodiment, a first O-ring is positioned along one end of a spindle axle socket and a second O-ring is positioned along a second end of the spindle axle socket to hermetically seal an area of the spindle axle therebetween.

An elastic member is an elastic member formed of a wire having a cross section that is substantially circular, the cross section being orthogonal to a longitudinal direction, and the elastic member being expandable and contractible in a predetermined direction; and including: a first alloy portion that is made of an aluminum alloy having a tensile strength larger than 950 MPa and equal to or less than 1100 MPa at room temperature; and a second alloy portion configured to cover the first alloy portion, the second alloy portion having a thickness in a radial direction smaller than a radius of the first alloy portion, and being made of an aluminum alloy having a tensile strength of 100 MPa to 650 MPa at room temperature.

An overload suspension system configured for operative engagement to a vehicle having a first leaf spring and second leaf spring to provide auxiliary support to the vehicle when overloaded. A first control arm attached to a first torsion bar has a distal end positioned a separation distance from the first leaf spring. A second control arm attached to the second control arm has a distal end positioned substantially the same separation distance from the second leaf spring. The suspension system operates as an auxiliary suspension only when added weight to the vehicle deflects both leaf springs to contact a respective one of the control arms, thereby preserving the ride and suspension characteristics of the vehicle when the added weight is not present.

The present invention relates to a suspension arrangement for a tracked vehicle. The suspension arrangement includes a road wheel arm having a wheel axle portion for supporting a wheel of the vehicle and a pivot axle portion. The road wheel arm is pivotably journalled at the pivot axle portion to a housing that is fixable to the vehicle body. A torsion bar is connected to the pivot axle portion and a torsion tube is arranged to be connected to the vehicle body, with the torsion bar running through the torsion tube and arranged to be connected to the torsion tube. The modulus of elasticity of the torsion tube material is lower than the modulus of elasticity of the torsion bar material such that the maximum suspension travel is increased.

A wheel suspension for a two-track vehicle having at least one stabilizer formed as a stabilizer torsion spring rod, with the stabilizer extending in the vehicle's transverse direction and having a drive lever on at least one vehicle side, which acts upon a wheel guidance element of the wheel suspension, and having at least one suspension spring, which is tensioned with a spring preload between the vehicle body and a wheel guidance element of the wheel suspension. The suspension spring is at least partially formed as a suspension spring/torsion spring rod. The suspension spring/torsion spring rod is arranged radially within the stabilizer torsion spring rod designed as a hollow rod.

A hollow stabilizer production method of a hollow stabilizer used for a vehicle includes attaching a first mounting member and a second mounting member respectively to one end and another end of a formed steel tube and heating the steel tube. The method includes feeding a carburizing gas into the interior space of the heated steel tube through the first mounting member, and collecting the air and/or the surplus carburizing gas from the interior space through the second mounting member to thereby carburize the steel tube inner surface. The method includes rapidly cooling the heated steel tube to thereby quench the steel tube continuously from the carburization.