AGMA 948-A26 The New Guideline for Electrified Vehicle Drivetrains

Electrified vehicles are reshaping the automotive industry, demanding new standards to ensure performance, reliability, and safety. Our Colleagues at The Motion + Power Manufacturers Alliance (MPMA) recently introduced AGMA 948-A26, a comprehensive guideline focused on electrified vehicle drivetrains. This document addresses the unique challenges and requirements of these systems, providing engineers and manufacturers with clear direction.

Why AGMA 948-A26 Was Needed

Electrified vehicle drivetrains differ significantly from traditional internal combustion engine drivetrains. They involve complex interactions between electric motors, gears, bearings, seals, and lubrication systems. Existing standards did not fully cover these aspects, especially considering the noise, vibration, and harshness (NVH) characteristics unique to electric drivetrains.

The new guideline fills this gap by offering a broad framework that supports the design, manufacturing, and maintenance of electrified drivetrains. It helps ensure that components work together efficiently and reliably under various operating conditions.

What the Document Covers

AGMA 948-A26 is a wide-ranging document that touches on multiple critical areas:

• Terminology: Establishes clear definitions to avoid confusion across different stakeholders.

• Duty Cycles: Describes typical operating conditions and load profiles for electrified drivetrains.

• Configurations: Covers various drivetrain layouts and system architectures.

• System Operating NVH: Addresses noise and vibration issues specific to electric drivetrains, which differ from combustion engines.

• Prime Movers: Discusses electric motors and their integration with mechanical components.

• Gear Design: Provides guidelines for gear geometry, materials, and performance criteria tailored to electric vehicle needs.

• Bearings and Seals: Details requirements for components that support smooth and durable operation.

• Conductance and Lubrication: Explains thermal management and lubrication strategies to maintain efficiency and longevity.

• Manufacturability and Maintenance: Offers advice on production processes and service considerations to support quality and ease of repair.

Abstract

"This document is a guideline for electrified drivetrains for vehicles. These drivetrains can be hybrid electric (HEV), battery electric (BEV or EV) or plug-in hybrid electric (PHEV) vehicles, with the prime mover power source or sources as any combination of battery, fuelled ignition engine, and/or fuel cell. These can generally be referred to as xEVs. The drivetrains covered include ground and marine applications such as passenger vehicle car or light truck, heavy duty/commercial, construction, agricultural, mining, tracked, propeller/waterjet, and similar drivetrains. Refer to notes below for exclusions. The prime movers may propel the vehicles in series and/or parallel power flow operation"

This guideline is available free of charge to AGMA members or can be purchased from their website directly: AGMA 948-A26