Vehicle Wheel and Tire Characteristics

Posted on Jan 11, 2025 in Electromechanical Engineering

Main Characteristics

  1. Pavement: Dampens irregularities encountered by a vehicle wheel.
  2. Functions: Bear vehicle weight, transmit power, secure the wheel, and facilitate braking.

Rim and Tire Terminology

The rim is the metal part of the wheel that supports the tire. It connects to the vehicle’s hub.

Types of Rims:

  • Deep Base Rim: One-piece rim with a deep center for easy tire mounting and removal. Features inclined seats.
  • Removable Wheels:
    • Semi-Deep: Less deep with a removable base for tab assembly.
    • Flat Base with Inclined Heel Seats: Primarily flat base with inclined heel seats. Multi-part construction.
    • Flat Heel Seats: Flat seats with at least one removable tab.
    • Sectorized: Dismantled into two halves along its longitudinal plane.

Terminology:

  • Width: Elevation of the rim profile between the inside of the tabs, measured in inches.
  • Tab Height: Maximum height of the flange from the nearest point on the heel seat.
  • Nominal Diameter: Diameter of the rim on the heel seat, measured in inches.
  • Rim Profile: Indicates the type of profile (e.g., tubeless, wide array, standard series).

Types of Tires (Disc Wheels)

Basic types include disc, radio, or portallantas wheels.

Wheel Drive:

The rim is connected to the hub via a disc at the center, attached by rivets or beads. Parts include:

  • Apollo Surface: Part of the disc that couples to the wheel bushing holes.
  • Fixing: Allows passage of fixing screws with conical seats for proper centering.
  • Diameter: Diameter of the circumference through the middle of fixing holes.
  • Central Hole: Hole in the center of the disc for the hub.
  • Pumping: Distance between the apollo surface and the longitudinal plane through the rim.
  • Valve and Ventilation Windows: Found in stamped steel and alloy wheels.

Tubeless Tires

Tubeless tires have an inner lining of butyl rubber for protection. Benefits include:

  • Slower air loss in case of puncture.
  • Better heat dissipation.
  • Lighter weight.
  • Easier assembly and disassembly.

Tires with Safety Valve:

Ordinary tires with a tube valve sealed by tightening.

Tire Construction

Components of a tire:

  • Rolling Band (Tread):
    • Contact Area: Part of the tire in contact with the ground.
    • Sculpture or Drawing: Grooves on the tread.
    • Indicators: Bands in the tread.
  • Heel Rings: High-resistance steel wire coated in rubber.
  • Shoulders: Joint between the tread and sidewalls.
  • Sidewalls: Sides of the tire from the tread to the heel.
  • Cord-Centered: Protrusion at the top of the heel for centering.
  • Rubber-Coated Interior: Airtight rubber layer vulcanized inside the tire.
  • Case or Frame: Provides resistance to the tire.

Types of Tires by Construction

  • Diagonal Tires
  • Radial Tires

Radial Tire Features

Features include:

  • Working independence between sidewalls and tread.
  • Less deformation of the contact surface.
  • Reduced friction.
  • Insulated flooring with vertical flexibility.

Advantages:

  • Minor increase in performance.
  • Reduced fuel consumption.
  • Better adhesion.