Fluid Power Research Group
Institute of Machines Design and Operation Wroclaw University of Technology, Poland


Location Wroclaw, Poland
Contact Persons Univ.-Prof. Dr. Hab. Ing. Jaroslaw Stryczek
Address Ul. Lukasiewicza 7/9
50-371 Wroclaw, Poland
Telephone number +48 71 320 20 70
Fax number +48 71 322 76 45
Email jaroslaw.stryczek@pwr.wroc.pl
Internet Site http://www.ikem.pwr.wroc.pl

From Editor

International Journal of Fluid Power would like to introduce the fluid power research and education centres with their expertise and particular interests in this column. Jumping from continent to continent we like to offer every research centre the opportunity to present itself.


FLUID POWER RESEARCH CENTRES WORLD-WIDE


General Information

Wroclaw University of Technology (WUT) was founded in 1945. It was housed in the buildings of the former Technische Hochschule Breslau, established in 1910. Nowadays, the University has 12 faculties and over 2,000 academic teachers, which are providing education for more than 32,000 students.

The Faculty of Mechanical Engineering (W10) has existed at the WUT from the very beginning. It is currently one of the largest and most important faculties at the University. Over 3,000 are studying in four fields of study:



Fig. 1:Wroclaw University of Technology

A part of the Faculty of Mechanical Engineering is the Institute of Machine Design and Operation (I16). The staff of the Institute consists of more than 100 academic teachers, including 25 professors and assistant professors. The Institute's didactics and research concern the design and operation of the following machine types:

The didactics and research concern the following areas:
As a part of the Institute, the Fluid Power Research Group is active in such teaching and research fields as fundamentals of machine design and fluid power.

1. Fluid Power Research Group

Education and research in the field of fluid power were initiated in the 1960s by Prof. Stefan Stryczek (1921-1997), fig. 2. He founded The Department of Hydrostatic Drive and Control and he organized the didactic specialization of Hydrostatic Machines. For almost forty years he delivered lectures on fluid power, promoted ten PhDs and dozens of M.Scs. Prof. Stefan Stryczek very closely co-operated with Polish industry. In 1976, he received the State Award for research on Polish loaders. He incorporated his experience in the two volumes entitled "Fluid Power Elements and Systems" (fig 2). The book has appeared in five editions thus far.



Fig. 2:Prof. Stefan Stryczek


In this scientific environment and tradition, the Fluid Power Research Group (fig. 3) formed itself in the beginning of the 1990s. The group is a part of the Institute of Machine Design and Operation. The head of the group is Prof. Jaroslaw Stryczek, and the members are:





Fig. 3:Fluid Power Research Group (from left: P. Antoniak, S. Bednarczyk, J. Stryczek, T. Greczanik, M. Banas)



2. Research Fields

The group's main fields of activity are:


2.1. Cycloidal gearings

The activity of Fluid Power Research Group began in the early 90s with two projects for KBN on the design and technology of cycloidal gearings used in hydraulic pumps and motors. This theoretical basis was utilized for manufacturing several sets of cycloidal wheels (fig 4), which were then applied in hydraulic machines produced by Polish industry. One of the industrial partners was Pilmet Company in Wroclaw, for which the group devised the design and technology of gerotor sets applied in Orbitrol steering units and Orbit hydraulic motors. At the end of the 90s Pilmet Company joined Sauer Danfoss Poland, and the new company still uses the design and technological solutions devised by the Fluid Power Research Group.



Fig. 4:Cycloidal gear sets



2.2. Gerotor pump

Utilizing the knowledge of cycloidal gears, the group systematically continued research on the development of hydraulic machines, such as gerotor pumps and low-speed motors. Part or this research was the project for KBN on the gerotor pump with axial clearance compensation (fig. 5). The prototype of this pump was manufactured and tested in PZL Hydral Company in Wroclaw. The pump has reached the operating pressure p=20 MPa and the total efficiency of = 0.8.




Fig. 5:Prototype of a gerotor pump with axial clearance compensation

2.3. Low-speed motor

The next research project for KBN included the design and testing of a low-speed high-torque motor with a double cycloidal gearing (fig. 6). The general idea of the motor came from Ing. Czeslaw Bald, who co-operated with the FPRG and manufactured the prototype in Pioma Company in Piotrkow Trybunalski. The motor is very compact, and its weight and dimensions are relatively small. Prof. Andrzej Balawender tested it at Gdansk University of Technology. The tests showed that its stoke displacement is high, with q=10000 cm³/rev, that it can operate with a low speed of n=1-40 min-1, and with a high torque of M=6500 N·m.



Fig. 6:Model of low-speed high-torque motor Max 11

2.4. Satellite motor

In co-operation with Prof. Balawender the FRPG performed computer simulations of case deformations and changes of axial clearance in the HS type hydraulic motors (fig 7). As a result of this research, detailed design recommendations concerning HS satellite motors were formulated.

2.5. Internal gearing pump

The symbol of fluid power is the gear pump. High hopes for development can be placed in gear pumps with involute internal gearing pumps. The FPRG in co-operation with WPH Company in Wroclaw has launched an innovative research concerning such pumps (fig. 8). They are expected to achieve high operating pressures and efficiencies combined with low noise emission.



Fig. 7:HS motor with compensation plates




Fig. 8:Internal gear pump


2.6. Multifunction Hydrostatic Machine

Another research project for KBN concerned the Multifunction Hydrostatic Machine. As fig. 9 shows, it consists on a gear unit and a rotary spool valve. A rigid coupling connects it to a driving motor and an operating machine. The machine co-operates with a fluid power system and can perform the following functions:


The machine was manufactured by PZL Hydral Company in Wroclaw. Fig. 10 presents the machine assembled into a drive system, during the experimental testing.





Fig. 9:Multifunction Hydrostatic Machine with the drive system




Fig. 10:Test stand of Multifunction Hydrostatic Machine



2.7. Mining machine

Recently, the FPRG has initiated a co-operation with a mining machines producer ZANAM, with the objective of devising an innovative design of a new fluid power system for a mining machine (fig. 11). The research is currently in progress.



Fig. 11:Fluid power system of mining machine


3. PhD theses of the FPRG members

In connection to scientific research projects and innovative design projects the members of the group work upon their PhD theses.

In the year 2000 S. Bednarczyk has completed a thesis entitled "Gerotor Pump with Axial Clearance Compensation". The same year he presented the results of this work on the 1st FPN-PhD Symposium in Ham-burg.

M. Banas has completed a thesis entitled "Forming of Static Characteristic of Multifunction Hydrostatic Machine Through Change of Its Design Parameters". He presented the results of his work on the 2nd and 3rd FPN-PhD Symposiums in Modena and Terrassa (fig.12).



Fig. 12:Mention of the paper in 3rd FPN-PhD Symposium


P. Antoniak is currently working on a thesis entitled "Forming of Flow Channel in Displacement Machines According to Gerotor Pump" and presented results of his work on the 3rd FPN-PhD Symposium in Terrassa. Fig. 13 displays some results of the research.



Fig. 13:Three dimensional graph of the pressure in the flow channel in gerotor pump


Greczanik is preparing a PhD thesis entitled "The Process of Designing Involute Internal Gearings for Hydraulic Machines" (fig. 8).

4. Co-operation with Polish and foreign scientific centers

The FPRG co-operates closely with the Universities of Technology in Gdansk, Warszawa, Poznan and Krakow.
The members of the group publish their papers in the 'Hydraulics and Pneumatics' scientific magazine, which has served the fluid power branch of Polish engineers for 25 years. Prof Jaroslaw Stryczek is the head of the Editorial Board of the magazine.

The FRPG members actively participate in organizing the Polish Fluid Power Conference, which has taken place in Wroclaw for 40 years. The FRPG collaborates with Prof. J. Nevrly (Brno, Czech Rep.), Prof. B. Pavlok (Ostava, Czech Rep.), Prof. M. Ivantysynova (Hamburg, Germany), Prof. E. Codina (Terrassa, Spain) and Prof. B. Jachno (Kiev, the Ukraine).


 

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