The constructional detail / skeleton of a typical automobile (heavy-duty-vehicle) tyre is as shown in figure (1). With c/s of tyre construction is shown in figure (2). The main parts of the tyre are in the figure.
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| Fig 1: Tyre construction_heavy-duty_radial-tyre [1] |
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| Fig 2: Tyre construction_c/s view [1] |
A tyre is made of three
basic elements viz. thread, body and beads. These elements are composed of
three incompatible materials - rubber, fabric and steel. The tread is meant to
take load, the beads provide a firm footing for the tyre one, the rim and the
body is a joining link between tread and the beads.
A tyre tread’s design is composed of five basic elements; tread blocks, grooves, sipes, cross slots and ribs. And have different thread patterns according to the purpose of application or use. To know more about tyre thread pattern, we discuss on the article "Tyre thread patterns or design" to learn more.
Several fabric layers or
plies are impregnated with special hard rubber. The outer edges of the plies on
either side are rolled over two thick steel wire beads which hold the plies
tight across the tread. The ends of the plies are impregnated with rubber to
keep them tight over the tread. The beads are, in fact, wire ropes with
individual wires wound and twisted to form a strong anchoring for the fabric
plies inside the body of rubber. The beads fit around the wheel rim on either
side and are properly reinforced to stay tight on the rim without loosening by
stretching. The plies are further bonded with the side walls of the tyre.
Cushioning layer: Also called cushion, this is
a layer or middle piece made of thin rubber between the tread plies and the
tread and acts as a cushion or damper.
Reinforcement: The reinforcement is made of woven
fabric, it is around the beads as a strengthening member ill the region of the
beads.
Chafer: Chafers are made of fabric with a
coating of rubber. They are placed around the outside of the beads to prevent
the rubber tyre from being chafed or abraded by the metallic rim.
Sidewall: Sidewalls of a tyre are like its
cheeks and made of special rubber compound with a good resistance against
abrasion. They are strong enough to resist flexing also.
Tread: The tyre tread is the contact surface
rolling on the road surface. It provides the traction necessary to propel the
vehicle forward by virtue of the friction between the two said surfaces. The
tread is moulded from relatively son, but tough rubber or an elastomer material
capable of withstanding the severe loads during travel. Special compounds are
used to improve the qualities of natural or even the elastomers in respect of
wear, heat resistance and better adhesion for the sake of improved traction
Depending on the application and severity of duty, tyres are given different
types of tread patterns which are provided in the tyre moulding process itself.
Tyre Constitutes: Basic elements of tyre viz. thread, body and beads. The fundamental materials of modern
tyres are synthetic rubber, natural rubber, fabric and steel wire (high tensile
steel / HTS for beads), along with other chemical compound. They consist of a
tread and a body. The tread provides traction while the body ensures support.
Tyres are made up of a naturally white rubber in which carbon black (pigment) is added to increase the strength and durability of the rubber. It also resists hot spots on the tyres. Also, tyres constitute have various metals such as titanium and cobalt along with fabrics such as nylon, rayon, and polyester for tyre body. [2]
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