RESEARCHES REGARDING THE MANUFACTURING TECHNOLOGY … · Researches regarding the manufacturing technology of a profiled rotor used in fluid circulation The Romanian Review Precision

Researches regarding the manufacturing technology of a profiled rotor used in fluid circulation

The Romanian Review Precision Mechanics, Optics & Mechatronics, 2016, Issue 49 7

RESEARCHES REGARDING THE MANUFACTURING

TECHNOLOGY OF A PROFILED ROTOR USED IN FLUID

CIRCULATION

Lecturer Daniel Besnea, PhD Eng., As. Mihaela Constantin PhD Eng., Evelina Donisan, PhD Student Eng., Roxana

Mechno, PhD Student Eng., Prof. Nicolae Băran, PhD Eng.

Affiliation: Politehnica University of Bucharest

Post address: Splaiul Independenței nr. 313, sector 6, Bucharest

E-mail: [email protected], [email protected], [email protected],

[email protected], [email protected]

Abstract - The paper has the following objectives: The rotor constructive solution presentation, that, in

conjunction with an adjacent rotor may form a reversible machine; The manufacturing technology

development of a rotor in two versions:

I. By processing on C.N.C I;

II. By using quick prototyping (manufacturing technology with material addition).

The end of the paper presents the results obtained in version I and II.

Keywords: Profiled rotors, rotating pistons, 3D printer.

1. Introduction

To achieve results concerning new constructive

solutions to any mechanism or machine, it must be

designed, developed and built as a model in the

laboratory. The theory underlying any machines are the

results obtained on the model in the laboratory.

Using the similarity theory of the results obtained in

the laboratory, it will be applied to the "natural model",

ie the prototype.

The paper presents a rotor model which will be used

to create a prototype.

The model constructive solution is original, it can be

applied in the field of rotating machines in the following

two model versions I and II:

If note: pa - aspiration fluid pressure; pr - discharge

fluid pressure, then, two versions follows [2]:

Version I: pa> pr, as force machine:

- Steam engine;

- Pneumatic engine or hydrostatic motor.

Version II: pa <pr, as working machine:

- Pump;

- Fan;

- Low pressure compressor.

The concept of the reversible machine refers to the

fact that the same construction can be used as:

- Pump (hydrostatic motor)

- Compressor (steam engine)

There are several possibilities to build the rotor

model:

- By machining

- By working on a numerical control center (C.N.C.)

- Using quick prototyping

2. The rotor framing in a fluid circulation system

The papers [2] [3] presented a mathematical model

for calculating the rotor contour, ie specifying the

coordinates (xi, yi) in xOy orthogonal system of the

rotor profile contour.

If now, the two rotors are assembled in a case, a

fluid circulation system (fig. 1) or a metering fluid

volume system results.

The fluid is transported to the discharge and after a

90° rotation of both rotors, the situation in Figure 1. b

and thereafter in Figure 1. c is reached.

After a 180° rotation the fluid contained in the useful

volume Vu (Fig. 1. b.), ie in the space between the

pistons 3’ and 4’, will be transported to discharge.

The two rotors are identical, tangent and rotates in

reverse.

Each rotor is symmetrical to Ox and Oy axis.

In order that the rotating pistons (1) and (2) of the

upper rotor (5) to enter into the cavities (1 ') and (2') of

the lower rotor (6), a cylindrical gear was performed

outside the machine comprising two gear wheels whit

the same division diameter.

This cylindrical gear ensures a synchronous rotation

of the two rotors.

mailto:[email protected]





Effects of immersion duration in water on strength of instrumented composite materials


a. b. c.

Figure 1. The operating principle of the volumetric meter 1, 2, 3’, 4’- rotating pistons; 1’, 2’, 3, 4- cavities in which the rotating pistons enters; 5-upper rotor; 6-

lower rotor; 7- upper case; 8- lower case; 9-upper shaft; 10-lower shaft

2. The manufacturing technology of the profiled

rotor

In this situation two constructive solution are

distinguished:

2.1. The rotor construction using a C.N.C.

2.2. The rotor construction with a manufacturing

technology with material addition.

Further, the two versions will be analyzed:

2.1. The rotor construction using a C.N.C.

CAD designing and execution CAM for numerically

controlled machines having 3 to 5-axis was performed

using the CATIA V5 software package which features a

powerful post –processing engine that allows the

coverage of the entire manufacturing process, from the

machining tool trajectory generation up to NC Code

software generation [4] [5]. Based on the coordinates,

using the Sketcher mode in the Profile toolbar Point by

Using Coordinates is selected and the points are inserted

into sketch by entering the Cartesian coordinate’s

Figure 2. The rotor execution precision on C.N.C. is

0.01 mm [6].

Figure 2. The profile defining through Cartesian

coordinates and the Spline application use

The defined points are merged with the Spline toolkit

and by Transformation tool using the Symmetry

controls the full rotor profile is defined (Figure 3).

Figure 3. The rotor profile defining

The extrusion on the Z axis can be achieved using a

drawn profile (Sketcher) in closed contour and by

activating the Pad Definition command enables the

extrusion on a normal direction to the drawing plan or,

by activating the Mirrored extend option, the extrusion

can be done in both senses of the normal, figure 4.

Figure 4. The rotor three dimensional model created

with the Pad option



After defining the rotor geometry, the working area

opens for the NC manufacturing process in a document

CAT Product that will determine the initialization of a

new executions within the manufacturing process and

the addition of a new entity to the Operation Part

structure (Figure 4).

The access to the operation parameters can be done

through the Part Operation dialog box where the

machine tool type can be choose (Machine - editor) and

where the specific parameters of the processing machine

can be defined (numerical command parameters, the

rotation parameters, the changing tool parameters, etc.)

[7] [8].

The Axis Machine icon activates to assign a

reference axis to the processing system in operation, the

Product icon is presses to associate an existing product

to a certain operations [9] (Figure 5):

Figure 5. Selecting the processing machine depending on the axes number

The Manufacturing Program mode allows the distinct

and different technological operations defining on

surfaces categories and according to the processing

type, roughing respectively finishing.

Depending on the rotor geometrical particularities the

ZLevel option is choose (processing a vertical surface)

with an end mills (Figure 6).

Figure 6. Milling operation simulation using the Video Mode



Figure 7. The machining tool trajectories in Photo Mode

The code language software generation, the machine is

achieved by activating the Generate NC Code icon

opening the active window in Figure 7 and, on the page

IN / Out The Document CAT Process is selected; the

file path that will be generated is specified, Output File,

in the NC date Type menu, the NC Code is selected

(Figure 8), and in the NC Code page the appropriate

postprocessor type corresponding to the numerical

control machining center (Fanuc 0) is selected.

Figure 8. The NC Code software generation

The rotors were constructed of duralumin, on C.N.C. Figure 9, 10.

Figure 9. Plan view of a profiled rotor Figure 10. . Plan view of the two profiled rotors



From Figure 10 one observes that the seal between the

two rotors is provided by:

- A contact between the lower rotor piston top and the

upper rotor cavity;

- Two contacts between the curved sides of the lower

rotor piston and the upper rotor cavity.

2.2. The rotor construction with a manufacturing

technology with material addition

Rapid Prototyping technology (Rapid Prototyping -

R. P.) is used for prototypes achievement or a reduced

number of parts, their architecture is given as CAD

(Computer Aided Design). The first rapid prototyping

machines development was due to Charles W. Hull,

who made the first machine SLA (Stereo Litographic

Apparatus).

Rapid prototyping stages, in order to achieve a rotor

prototype are [10]:

Step 0: Creating a CAD file;

Step 1: Creating STL file (Standard Triangulation

Language To Layer);

Step 2: STL files processing;

Step 3: Building the prototype layer by layer;

Step 4: Post processing operations

Rapid prototyping process for manufacturing the

profiled rotor, essentially, consist of the following:

The thermoplastic material (PLA), in filament form, Ø

1.75 mm, is heated to a temperature of 215oC and it is

deposited on the work surface using an extrusion head

which has at the top, a dose with Ø 0.2 mm.

Figure 11. The rotor of the Maker Bot Replicator machine platform

The dose is able to perform movements on all three

axes, above the rotor fixed on the machine platform

(Figure 11).

Unlike the conventional manufacturing processes,

the R.P. processes is based on building prototypes by

adding material; a prototype can be considered as

consisting of a sequence of layers of very small

thickness.

The prototype is built layer by layer; the material is

deposited on the previous layer at the calculated level

position, by the computer.

The construction of each layer, first, begins through

submitting thermoplastic material on the rotor contour.

Figure 12 shows the two rotors constructed of plastics

materials.

Figure 12.Rotors built with the R.P. technology



3. Conclusions

- For the rotor manufacturing, a computing program

specifying the coordinates (xi, yi) of the rotor profile

contour must be achieved; subsequently, this program is

used to achievement of the profiled rotor.

- The rotor can be easily constructed because the

execution technology of the rotor and the case is based

on a numerical command program and their execution is

performed using a C.N.C. or rapid prototyping.

- The C.N.C. accuracy ensure a satisfactory sealing

between the two rotors and between the rotors and the

case.

- The execution accuracy of the rotors is:

I. By processing on C.N.C.: - 0.01 mm;

II. By using Rapid prototyping: 0.1 mm.

Obviously, the first method is more advantageous.

- In operation, at the speed of 300 rpm and assuming

that warm fluids circulates, version I is preferred, within

which the rotors are built of duralumin, not plastics.

4. References

[1] A. Motorga, „Influența parametrilor constructive și

funcționali asupra performanțelor mașinilor rotative cu

rotoare profilate”, Teză de doctorat, Facultatea Inginerie

Mecanică și Mecatronică, Universitatea,

POLITEHNICA din București, București, 2011.

[2] A. Detzortzis, „Influența arhitecturii rotoarelor

asupra performanțelor compresoarelor volumice rotative

cu rotoare profilate” Teză de doctorat, Teză de doctorat,

Facultatea Inginerie Mecanică și Mecatronică,

Universitatea POLITEHNICA din București, București,

2014.

[3] N. Băran, D. Besnea, A. Motorga, ,,Elements of

computing the architecture and manufacturing

technology for a new type of profiled rotor”,

PROCEEDINGS International Conference, 6th

Workshop on European Scientific and Industrial

Collaboration on promoting Advanced Technologies in

Manufacturing, WESIC’08 Bucharest 25-26, 2008, pp.

233-241.

[4] N. Băran, O. Donțu, D. Besnea, A. Costache,

„Constructive elements and technological procedures

used in the construction of a new type of rotating

compressor”, Romanian Review Precision Mechanics,

Optics & Mechatronics, nr. 2/2004, București, pp. 261-

268.

[5] D. Besnea, N. Băran, A. Costache ,

,,Manufacturing Technology for a New Type of Profiled

Rotor Used in the Construction of Rotating Machines”

,Proceedings of the 2nd International Conference on

Innovations, Recent Trends and Challenges in

Mechatronics , Mechanical Engineering and New High-

Tech Products Development MECAHITECH 10, ISSN

2068-648x, Bucharest, 23-24 September 2010 , pp. 18-

27.

[6] V. Tcacenco, Centre de prelucrare cu ax vertical

„Alzmetall” Rev. Tehnică și Tehnologie nr. 4, 2005, pp.

16-17.

[7] A. Zaid, N. Băran, D. Duminică, ,,Research

Regarding the construction of a new type of profiled

rotor” Romanian Review Precision Mechanics, Optics

& Mechatronics”, Nr.30, 2006, București, pp.721-724.

[8] N. Băran, D. Besnea, A. Detzortzis, A. Bărăscu,

,,Manufacturing technology of a new type of profiled

rotor used by a rotating volumetric pump”, Proceedings

in Manufacturing Systems, Vol. 7, Iss.2, 2012, pp. 105-

110.

[9] N. Băran, D. Besnea, A. Detzortzis, C. Cărnaru,

„Manufacturing Technology for a new type of a new

type of Profiled Rotor”, Trans Tech Publications,

Switzerland, Advanced Materials Research, Vols. 655-

657, 2013, pp. 235-240.

[10] P. Bercea și col., „Tehnologii de fabricație prin

adăugare de material și aplicațiile lor”, Editura

Academiei Române, București, 2015.

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RESEARCHES REGARDING THE MANUFACTURING TECHNOLOGY … · Researches regarding the manufacturing technology of a profiled rotor used in fluid circulation The Romanian Review Precision