To understand the forces acting on a starter motor let us first consider a single conducting wire in a magnetic field.
New developments in starting systems
Gates, well known as manufacturers of drive belts, are working on a starter-generator concept that is belt driven. This work has been carried out in conjunction with Visteon. It is known as the Visteon/ Gates E-M DRIVE System. It is an electromechanical system made up of a high efficiency induction motor, long-life belt-drive system and sophisticated electronic controls. The belt-driven starter-generator replaces the current alternator and has a similar space requirement.
One of the key components of this system, in addition to the starter-generator is a hydraulic tensioner. This must be able to prevent significant movement during starting but also control system dynamics during acceleration and deceleration of the engine. A dual pulley tensioner concept is shown below.
Addition to the starter-generator is a hydraulic tensioner. This must be able to prevent significant movement during starting but also control system dynamics during acceleration and deceleration of the engine. A dual pulley tensioner concept is shown below.
The starter-generator concept is not new but until recently it could not meet the requirements of modern vehicles. These requirements relate to the starting torque and the power generation capabilities. The biggest advantage of the system under development is that it can be fitted to existing engine designs with only limited modifications.
Multiple choice questions
The purpose of the pull-in winding in the operating solenoid of a pre-engaged starter motor is to:
- Hold the pinion in mesh
- Pull the pinion out of mesh
- Hold the pinion out of mesh
- Pull the pinion into mesh
Technician A says a spring is used to hold a reengaged starter pinion in mesh when cranking the engine. Technician B says a holding coil holds the pinion in the engaged position during starting.
Who is right?
- A only
- B only
- Both A and B
- Neither A nor B
A one-way clutch in a pre-engaged starter motor:
- Prevents the engine driving the motor
- Prevents the motor driving the engine
- Stops the motor when the engine starts
- Starts the motor to turn the engine
Technician A says permanent magnet starter motors are suitable for large diesel engines because of their low speed and high torque. Technician B says permanent magnet starter motors are suitable for small petrol engines because of their high speed and low torque.