The workbook contains 21 project exercises designed for equipment sets TP 801, TP 802 and TP 803 together with the corresponding exercise sheets and sample solutions. It thus provides a comprehensive course companion conveying the essential knowledge and basic principles of the hydraulic systems of mobile machines.
The workbook contains:
- Basic information
- Exercise sections comprising project exercises and sample solutions for TP 801, TP 802 and TP 803
- Training notes
- Worksheets for students
- Courseware on data storage media/download
The basic level contains the following topics:
- Definition of terms and basic principles of hydraulics
- Closed hydraulic circuit
- Load-sensing systems and variable displacement pumps
- Flow divider
- Mobile control blocks
- 6/3-way proportional valves and valve configurations
- Pressure balances
- Holding and lowering loads
- Hydraulic pilot control (joystick)
- Priority valves
- Steering systems
Exercise section TP 801
Working hydraulics 1
This training section, made up of 9 project exercises, is designed for the equipment set TP 801.
Each project exercise begins by presenting the training objectives which can be achieved. Next, the vehicle or application under discussion is presented. Parameters are provided to ensure a uniform starting point, and the project goal ensures a structured approach.
- Of flow control
- Of open centre load sensing
- Of a proportional valve (supply)
- Of a proportional valve (supply and discharge) with and without open centre load sensing
- Of a proportional valve with pump bypass with and without loaded cylinder
Holding load, lowering load
- Holding load (piloted non-return valves)
- Lowering load (counter pressure)
- Lowering load (counterbalancing valve)
Circuits with multiple loads
- Features of parallel connection
- Features of tandem connection
- Features of series connection
Exercise section TP 802
Hydrostatic steering system
This training section, made up of 5 project exercises, is designed for the equipment set TP 802.
During all project exercises, trainees set up a circuit as per the instructions and the relevant circuit diagram, and carry out measurements and calculations. Each project exercise ends with a series of questions are asked to test trainees' understanding. The measurements, calculations and answers can then be compared with the sample solutions and discussed.
Basic principles of hydrostatic steering
- Structure of a steering system with through-rod cylinders
- Structure of a steering system with two differential cylinders
- Displacement of the steering valve
- Emergency steering characteristics of the steering valve
- Loads and overloads in the steering system
- Torque dependency of the steering valve
- Priorities of the steering system and secondary loads
Exercise section TP 803
Working hydraulics 2
This training section, made up of 7 project exercises, is designed for the equipment set TP 803.
The content builds on the training content of TP 801, Working hydraulics 1 and expands it to include the complex topic of systems with a variable displacement pump with load sensing control. However, the complexity is kept to a manageable level because the project exercises are progressive, each building on the one before.
- Design and function of a control block
- Control block with closed centre load sensing
- Control block with two loads
- Flow rate limitation on the control block
- Pilot control of a control block
- Dependencies of load and flow
- Functioning of an upstream pressure balance
- Pressure compensation for load sensing
- Characteristics of upstream pressure balances when there is more than one load
- Characteristics of downstream pressure balances when there is more than one load
L. Unan, U. Schedel, C. Löffler
Edition 2013, 540 pages, in colour, in folder.