Gates and barriers driving mechanism.

Filipoiu, Ioan Dan ; Seiciu, Petre Lucian ; Morariu, Zaharie 等

1. INTRODUCTION

The driving mechanism is the main component element of the closing system of some precincts with gates, barriers, doors (commercial centers, public institutions, companies head quarters, garages and parking places).

Figure 1-3 present three different mechanisms (1 is the driving mechanism and 2 is the gate, Hamrock et al., 2005).

The actual systems use several types of driving mechanisms: gear, chain drive, belt drive mechanisms, screw-nut systems etc. Usually these systems are expensive and less reliable due to many expensive parts they have (Decker, 2007). There are several companies that produce such systems, but they are CC powered and they have large overall sizes.

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2. THE MECHANISM FUNCTIONS

The driving mechanism has the following functions:

* horizontal rotation of gateways and doors and/or vertical rotation of barriers;

* maximum angle between normal closed and normal open working positions: 90[degrees];

* working speed range: 6...12 m/min;

* functioning reliability: 100%;

* switch or remote commands to be performed from maximum 10 m;

* manual operating when electrical power is shut-down;

* IP54 protection level;

* total security of the open/close system.

3. DRIVING MECHANISM CONSTRUCTION

The mechanism (Filipoiu et al., 2006) consists in a gear reducer A and an articulated driving mechanism for the barrier or a quadrilateral mechanism articulated with levers for gates and doors (figure 4).

The decelerator A consists in a worm gear and two helical gears.

The open/close system with gear and supplementary lever transmission, can work in closed or open environment, heated or not, at temperatures between--20...+ 70[degrees]C. It can be placed in or out of buildings and has easy and safe access to the open/close system in case of malfunction.

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In case of power shut-down, the system can be manually driven by cutting-off the cinematic chain.

The open/close system has an IP54 protection level against dust and water according with SREN 60529-95.

The open/close system consists of the following parts presented in figures 4 and 5.

The electrical Motor (2MA 63--90 W and 860 rpm) has a special construction, different from the standard version. The gear worm is cantilevered on motor's shaft, for minimum size.

The driving mechanism (three speed reduction ratio) has one cylindrical worm gear and two coaxial helical gears, is case mounted with a vertical separation section (Filipoiu & Tudor 2004).

The two bronze bearings of shaft III are mounted in the driving mechanism semi-cases. Due to overall size reasons, shaft I and tubular shaft IV are mounted on ball bearings.

The tubular shaft IV is mounted inside the free shaft II. The exit shaft V has two free ends and it is mounted inside the tubular shaft IV, forming with this a channeled assembly. The shaft's free end in the driving lever area is channeled while the other end is ridged in order to be manually driven.

In extreme situations of malfunction or electrical power failure, the gate has to be manually actuated. In these situations, the cinematic chain is interrupted by moving the key that releases gear [z.sub.4] from shaft III. In these conditions it is possible to free rotate the intermediary shaft III. This way, shaft's V striated end can be manually rotated, together with shaft IV, gear [z.sub.5]-[z.sub.6] and shaft III. The helical gear [z.sub.3] is fixed.

4. CINEMATIC ASPECTS

Figure 6 presents the synthesis of the quadrilateral articulated mechanism (with the gate shown in two positions).

This diagram is used for computing the lengths, the speeds and the accelerations of all the elements of the system. Figure 7 presents the speed poligon (Seiciu & Stanciu 2002).

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Figure 8 presents the acceleration polygon.

Figure 9 presents the force poligon. All the values in figures 6-9 are computed considering the respective scales. The figures 6-9 are drawn for the initial possition: gate is closed and starts to open (Uicker et al., 2003).

The force polygon is used as input data for the resistance calculus (design and verification) of the mechanical parts.

5. CONCLUSIONS

The system is an original product and was developed as a prototype. The innovative features are:

* the system has multiple use;

* small overall size, high efficiency;

* low mass weight;

* switch or remote opening and closing command;

* easy and safe handling and use in emergency cases (i.e. power shut-down).

The manufacturing price is competitive face to other similar systems. The system was produced and tested as part of an innovation project.

6. REFERENCES

Decker, K.-H. (2007). Machine Elements (in German), Carl Hanser Verlag, ISBN: 978-3-446-41054-0

Filipoiu, I. D. & Tudor, A. (2004). Design of the Mechanical Transmissions (in Romanian), BREN Ed., ISBN: 973-814326-8, Bucuresti

Filipoiu, I. D.; Morariu, Z.; Barbu, V. & Chesnoiu, A. (2006). Driving Mechanism for Door Open/Close Systems (in Romanian). Inovative Tehnology -CMRevue, Vol. 58, No. 1, January 2006, pp. 13-18, ISSN: 0573-7419

Hamrock, B. J.; Schmid, S. R. & Jakobson, B. (2005). Fundamentals of Machine Elements, McGraw Hill, ISBN: 0-07-246532-8

Seiciu, P. L. & Stanciu, S. (2002). Planar Mechanisms (in Romanian), BREN Ed., ISBN 973-648-074-7, Bucuresti

Uicker, J. J.; Shigley & Pennock, G. R. (2003). Theory of Machines and Mechanisms, Oxford Univ. Pr., ISBN: 97801-95-15598-3, New York