suspension 2B

Discussion on the treacherous nature of BC's terrain in North America.
Heavy loads are characteristic of operations in this region, leading to significant equipment wear and challenges.
Importance of proper testing for equipment in severe conditions.

Definition: Elements that work in coordination with air suspension systems to maintain desired ride height of vehicles.
Components associated with height control valves:
- Pressure Protection Valve:
- Maintains air pressure in the system to prevent leaks.
- Opens to deliver air supply only when reaches $80 ext{ PSI}$ .
- Closes when there is a loss of pressure in the supply system, maintaining sufficient air pressure at the height control valve.
- Airbags: Adjust height depending on the load and road conditions.

Visual explanation of the valve's operation:
- Arm linked to the differential of the axle, influenced by axle movement (up/down) in relation to the frame rail.
- Axle movement causes the arm to pivot, managing air pressure in airbags:
- If axle drops: arm pivots down, causing air to exhaust from airbags.
- If axle raises (i.e. load removal): arm pivots up, allowing air inflow to airbags.
Constant adjustment to maintain parallel alignment with the frame rail regardless of the load and terrain effects.

Consists of three ports:
1. Supply Port: Connected to the air supply tank or air dryer.
2. Delivery Port: Sends air to airbags.
3. Exhaust Port: Allows air release from airbags.
Ride Height Definition: Distance specified by manufacturers from the frame rail to the axle or bump stop. Critical for vehicle stability and performance.
Adjustability: The linkage can be adjusted to change ride height:
- Longer linkage increases ride height.
- Shorter linkage decreases ride height.

Electronic sensors, similar to optical sensors, communicate with the Electronic Control Unit (ECU) to maintain ride height automatically.
Examples of vehicles with such systems include GMC Yukons and Cadillac Escalades, where electric motors function to adjust suspension based on ride height requirements.

Discussion on poor suspension designs:
- Example: Kenworth eight-bag suspension, which consists of two airbags per axle in tandem trucks.
- Risks associated with suspension design failures, particularly axle alignment issues at high speeds, potentially leading to severe accidents.
Emphasis on the normal operations and maintenance related to these suspension designs and the frequent breakage due to shock and load.

Varieties of trailer suspensions, including:
- Leaf Pack Suspension: A standard tandem axle trailer configuration. It rides on equalizers which allow leaf springs to pivot freely.
- The role of equalizers in maintaining stability and ride quality is critical as they absorb shocks and adjust the load between leaf springs.
Mechanics of the spider suspension design highlighted to show how it deflates and inflates airbags to manage ride height effectively.

Overview of Hendrickson's Innovations:
- The history of innovation from early suspension systems to modern advancements in lift axles.
- The pursuit of weight reduction and efficiency in design exemplified by the composite ST series suspension.
Key features of the SC series suspension:
- Reduction of system weight up to $69 ext{ lbs}$ per axle.
- Enhanced installation flexibility and compact design (22.1 inches of package space).
- Emerging technologies such as the compliant tie rod (CTR) that provides an effective dampening system and self-centering mechanism.

Explanation of vehicle load impact on air pressure in the suspension bags:
- An increase in load leads to an increase in air pressure within the bags to maintain proper ride height.
Understanding these systems is crucial for effective vehicle performance and safety under varying load conditions.

Understanding of the suspensions and height control mechanisms is essential for maintenance and operation of heavy-load vehicles in challenging environments. The integration of advanced technologies, pressure-sensitive systems, and proper adjustments is crucial for effective vehicle functionality and safety.