EP2700820A1

EP2700820A1 - Motor-securing system

Info

Publication number: EP2700820A1
Application number: EP11863904.6A
Authority: EP
Inventors: Antonio FERNÁNDEZ-ESCANDÓN ORTIZ
Original assignee: Talleres Zitron SA
Current assignee: Talleres Zitron SA
Priority date: 2011-04-20
Filing date: 2011-04-20
Publication date: 2014-02-26
Also published as: WO2012143580A1; EP2700820A4

Abstract

The present invention relates to a system for securing a motor to the casing of a fan in the roofs of road tunnels, said system comprising a B30-type motor (3) including 8 radially and longitudinally distributed securing elements, with 4 angularly equidistant securing elements being located in the front portion of the motor (3) and 4 angularly equidistant securing elements being located in the rear portion of the motor (3), the casing (1) being provided with 8 perforations. The invention also comprises 8 adjustable tensioning members (4, 5) which are connected at one end to the securing elements of the motor (3) and, at the opposite end, to the casing (1) by means of the aforementioned perforations.

Description

OBJECT OF THE INVENTION

The present invention, as indicated in the wording of this specification, relates to a system for securing a motor, specially designed for its attachment to the inner face of the casing of a fan. Said fan is intended for its installation inside road tunnels for the ventilation thereof. In order to achieve the objective stated, the system comprises a number of adjustable tensioning elements which, by means of mechanical connections, enable a firm connection of the motor to the casing of the fan, reducing the weight and avoids being an obstruction to the air that flow through the casing.

BACKGROUND OF THE INVENTION

In the state of the art known, the casings are manufactured with a motor bracket welded to the outer shell thereof. This motor bracket could be welded fundamentally in two positions; in the upper area, or in the lower area of the casing. This type of construction caused an ovalization in the casing due to the weight of the motor and the bracket, since all this weight was held on a small part of the casing. Furthermore, the lack of rigidity of the bracket caused vibrations in the structure due to, in addition to the little rigidity of the motor bracket mentioned, the limited surface of the connection between said bracket and the casing. When the ovalization was significant enough, it could even cause the friction of the rotor blades with the shell of the casing, with the consequent problems that these bring about, such as the destruction of the casing and the rotor, or a greater friction, and thus, an increased electric consumption and a reduced performance of the fan.
The attachment between the casing and the motor bracket is carried out conventionally by means of welding beads. In this type of constructive solution each one of the parts that compose the securing system, outer shell, motor bracket and welds, were resistant elements, each of which cannot be removed or lightened without affecting the rest.
In addition to the mechanical problems of this constructive solution, it also generated aerodynamic problems. The motor bracket produced a significant aerodynamic obstruction of the air flow in both directions. The construction itself of the bracket requires it to be welded to the casing radially in a longitudinal direction, which causes an interference with the direction of rotation of the stream of air, thus causing turbulences and then reducing the performance of the fan.
Another well known constructive solution is the addition of motor brackets that have the same shape as the rotor blades. These blades are welded to the motor and to the shell of the casing. This solution, although it reduces the instability problems generated by the existence of obstructions in the air flow, causes, on the other hand, a significant obstruction in the air flow since these fixed blades are in the entire air flow passage and furthermore, generate a considerable increase in weight of the fan, which results in the need to provide much more robust fan support systems.
The securing system described in the present application overcomes the previously indicated problems; specifically, it overcomes the mentioned mechanical problems as well as the mentioned aerodynamic problems.
The present invention, due to an improved distribution of the loads inside the casing of the fan, allows the reduction of the amount of manufacturing material of all parts that comprise the casing, furthermore, it turns the outer shell principally into a "container" element, reducing significantly its thickness and obtaining, therefore, a significant reduction of the material used for its manufacture. The elimination of the motor bracket itself reduces the weight of the invention considerably. In addition, its elimination implies the elimination of the aerodynamic problems generated, since the tensioning elements that are used in the present invention are small enough for the instabilities in the air flow generated by these, to be negligible and not affect the performance of the fan.

DESCRIPTION OF THE INVENTION

In order to achieve the objectives and avoid the disadvantages previously indicated, the invention consists in a system for securing the motor to the casing of the fan, comprising at least 8 tensioning elements, at least 4 of which are inclined tensioning members. These tensioning members will preferably be adjustable tensioning members enabling the perfect centered of the motor in the casing of the fan and, in turn, the elimination of the motor bracket, which has a great aerodynamic impact and generates instabilities in the outward air flow that moves the rotor of said fan. In this way, the air flow that the fan generates is clean in both directions and does not have interferences, minimizing the turbulences generated in the air stream and consequently the aerodynamic efficiency is improved and the electric consumption of the fan is reduced whilst improving the thrust.
Thus the motor securing system of the present invention is intended for the support and securing of motors located inside the casing of a fan, these fans being specially designed for installation in roofs of road tunnels. The system object of the invention comprises securing a B30 or "pad mounting" type motor, including 8 radially and longitudinally distributed securing elements, with 4 angularly equidistant securing elements being located in the front portion of the motor, at angular distances of 90°, and with 4 angularly equidistant securing elements located in the rear portion of the motor, at angular distances of 90°.
The casing of the fan will comprise 8 perforations to house one of the ends of each one of the tensioning members. Said perforations will be located angularly equidistant, four by four, in two transversal sections of the casing and in the same way each one of them will be separated by angular distances of 90°.
Thus the present invention will comprise 8 adjustable tensioning members which are connected at one end to the securing elements of the motor and at the opposite end to the casing, by means of the perforations made, being 4 of these adjustable tensioning members inclined. The other 4 adjustable tensioning members will be selected among 4 straight tensioning members and 4 inclined tensioning members.
In an embodiment of the invention where there are 4 inclined tensioning members and 4 straight tensioning members, the tensioning members are arranged in a way selected among:

the 4 inclined tensioning members in the front portion of the motor and the 4 straight tensioning members in the rear portion of the motor;
the 4 straight tensioning members in the front portion of the motor and the 4 inclined tensioning members in the rear portion of the motor;
2 straight tensioning members and 2 inclined tensioning members in the front portion of the motor; and 2 straight tensioning members and 2 inclined tensioning members in the rear portion of the motor, all of these located as opposite pairs;

When there are 8 inclined tensioning members, the 4 tensioning members of the front portion of the motor will be inclined in an opposite way to the 4 inclined tensioning members of the rear portion of the motor.
Thus, and depending on the different possible embodiments, there will always be 2 or 4 straight tensioning members in the front portion of the motor and 2 or 4 inclined tensioning members in the rear portion thereof, except in the cases in which the 8 tensioning members are inclined. When there is a mixed design of tensioning members, that is, when there are two straight tensioning members and two inclined tensioning members in the front portion or the rear portion of the motor, these will be arranged in opposite pairs to best compensate the thrust generated by the motor.
The straight tensioning members provide a greater robustness to the attachment or securing of the motor, while the inclined tensioning members provide a better absorption of the thrust of the motor, therefore the combination of both types of tensioning members improves the performance of the attachment. Therefore, the most preferred embodiment has foreseen the installation of two straight tensioning members and two inclined tensioning members, in the front portion of the motor, arranged in opposite pairs; and two straight tensioning members and two inclined tensioning members in the rear portion of the motor. Furthermore, said tensioning members will be arranged in such a way that one straight tensioning member of the front portion of the motor corresponds with one inclined tensioning member of the rear portion in the same longitudinal plane of the securing element. With this arrangement of the tensioning members, the absorption of forces is maximized assuring a sufficiently robust attachment of the motor to the casing at the same time.
In a preferred embodiment of the invention, the casing of the fan includes in its outer face, at least 4 welded omega profiles along the width of the casing. Each omega profile is welded onto the line set by each pair of perforations, one corresponding to a front tensioning member and another to a rear tensioning member. Each omega profile comprises at least two perforations on each one of which a cap is welded to provide a greater robustness to the subsequent attachment of the tensioning member. In addition, the four omega profiles will be arranged in such a way that the perforations made in them coincide with those made in the casing so that the ends of the tensioning members pass through the casing and the profiles and are attached by means of the previously mentioned omega profiles, making the attachment more robust. The profiles also provide a greater structural robustness to the casing.
In another preferred embodiment of the invention, the straight tensioning members comprise a straight thread bar which is secured by one end to the securing element of the motor by means of a nut and a locknut and that is secured by the opposite end of the thread bar to the casing by means of a nut on the outer face of the casing, more specifically, on the outer face of the corresponding omega profile, and one with a locknut on the inner face of the casing.
In another preferred embodiment of the invention, the inclined tensioning members are designed to be comprised in three sections. A first section is a straight thread bar that articulates respect with a second section at one of its ends and that is joined to the casing at the end that is not connected, by means of a nut on the outer face of the casing and by means of a locknut on the inner face of the casing. A second straight section, that connects on both ends to the first thread section and to a third thread section. And a third thread section that joins to the securing element of the motor by means of a nut and a locknut on the end that does not connect and that connects to the second section on the other end.
In another preferred embodiment of the invention, the articulated ends of the first and third section will be flattened and will have a threaded through hole for fitting a pin into, located on each one of the connected ends of the second section. Furthermore, the connected ends of the second section will comprise a fork with a threaded through hole in which each one of the flattened sections of the first and third section will be inserted and through which a thread stud is inserted for the complete attachment of the connection. These studs that are used for attaching the connections are attached to said connection by means of a nut and a locknut located one on each side of the fork.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1.- Shows a general view of the invention with the tensioning members distributed in one of the possible embodiments of the invention.
Figure 2.- Shows a detailed view of a straight tensioning member.
Figure 3.- Shows a detailed view of an inclined tensioning member.
Figure 4.- Shows a cut view of an omega profile as those used in the present invention.
Figure 5.- Shows a cut of the omega profile whereby the caps through which the tensioning members are fixed to the outer shell of the casing are shown.
Figure 6.- Shows a detailed view of the join between the tensioning members to the motor and to the casing by means of the omega profiles.

DESCRIPTION OF VARIOUS EXAMPLES OF EMBODIMENT OF THE INVENTION

The following, by way of non-limitative example, is a description of the various examples of embodiment of the invention, making reference to the numeration adopted in the figures.
Figure 1 shows a first example of embodiment of the invention. It should be noted that the arrangement of the tensioning members is only one of the possible embodiments, as they can be positioned in any other arrangement provided that en each one of the 4 support planes (support plane being understood as the plane formed by each pair of the tensioning members joined to the omega profile itself (2)) has one straight tensioning member (4) and one inclined tensioning member (5) or two inclined tensioning members (5). Said Figure 1 shows the casing (1) to which the 4 omega profiles (2) have been welded in each one of the 4 support planes, to which the motor (3) is secured, by means of 8 adjustable tensioning members (4, 5). Said tensioning members (4, 5) are positioned in such a way that in the front portion of the motor (3) there are two straight tensioning members (4) and two inclined tensioning members (5) and in the rear portion of the motor (3) there are two straight tensioning members (4) and two inclined tensioning members (5). All of these are positioned in opposite pairs. Furthermore, the inclined tensioning members (5) are inclined towards the central part of the casing (1). In other possible embodiments, the inclined tensioning members (5) can be inclined towards the outer part of the casing (1). As observed in Figure 1, the tensioning members (4, 5) are joined to the motor (3) by means of a screw connection (6) and are joined to the casing (1) through some holes made in the casing itself (1) and in the omega profiles (2) and are held using nuts (7) placed on the outer face of the omega profiles (2).
Figure 2 shows a straight tensioning member (4) in detail. Said straight tensioning member is a thread bar (the thread is not shown in the figure) which has a locknut (9) on the end that connects to the motor (3) to secure the screwing of the screw connections (6). On the opposite end, the straight tensioning member comprises a locknut (8) to secure the connection on the inner face of the casing (1) and a nut (7) on the outer face of the omega profile (2). Due to the screwing of the entire straight tensioning member (4) the diameter of the casing can be adjusted with no more than by moving the nut (7) and the locknut (8) through said tensioning member (4).
Figure 3 shows an inclined tensioning member (5) in detail. Said inclined tensioning member comprises 3 sections (14, 15, 16). The central section (14) is smooth and has a fork (10) in each one of its ends, for supporting the other two end sections (15, 16) allowing the tilting thereof. The two end sections (15, 16) are threaded (it should be noted that the thread is not shown in the figure) having, at the ends that are in contact with the forks (10), some flattenings (11) to be inserted into said forks (10). Both the froks (10) and the flattenings (11) have a through hole through which a stud (12) is inserted in order to attach the sections (14, 15, 16) of the inclined tensioning member (5) together. The stud is attached by means of a nut (13) and a locknut (the locknut is not shown in the figures). In the same way as the straight tensioning member (4), the inclined tensioning member (5) has a locknut (9) on the end section (15) screw connected to the motor (3), for securing the screwing of the screw connections (6). On the opposite end (16), the inclined tensioning member (5) comprises a locknut (8) to secure the connection on the inner face of the casing (1) and a nut (7) on the outer face of the omega profile (2). Due to the screwing of the two ends (15, 16) of the tensioning member (5), the diameter of the casing (1) can be adjusted with no more than moving the nut (7) and the locknut (8) through said end sections (15, 16).
Figures 4 and 5 show a view of the omega profile and its longitudinal cut. Specifically, Figure 4 shows an omega profile (2) on which two perforations (18) have been made in the upper face for passing the thread ends of the tensioning members (4, 5) through and securing them with nuts on said external face of the profile. The omega profiles have their ends adapted to the shape of the casing to which they are welded, the casing shown in this figure being one of the possible embodiments. The figure shows the omega profile (2) welded to the casing on its lower face and on its ends. On the perforations, (18) some welded caps (19) are inserted in order to reinforce the joining of the tensioning members (4, 5) to the casing (1) and to make the structure more rigid.
Figure 6 shows the connection of the tensioning members (4, 5) to the casing (1) and to the motor (3) in detail, the casing being connected in turn to some noise absorbers (20).

Claims

Motor-securing system located inside the casing of a fan for installation in roofs of road tunnels, characterized in that it comprises a pad mounting type motor including 8 radially and longitudinally distributed securing elements, with 4 angularly equidistant securing elements being located in the front portion of the motor, and 4 angularly equidistant securing elements being located in the rear portion of the motor, the casing having 8 angularly equidistant perforations being located four by four on two cross sections of the casing, and comprising 8 adjustable tensioning members which are connected at one end to the securing elements of the motor, and at the opposite end, to the casing, by means of the perforations made, being 4 of the adjustable tensioning members articulated and axially inclined tensioning members and the other 4 adjustable tensioning members being selected among 4 straight tensioning members and 4 articulated and axially inclined tensioning members.
Motor-securing system, according to claim 1, characterized in that when there are 4 articulated and axially inclined tensioning members and 4 straight tensioning members, the tensioning members are arranged in a way selected among the following:
• the 4 inclined tensioning members in the front portion of the motor and the 4 straight tensioning members in the rear portion of the motor;

• the 4 straight tensioning members in the front portion of the motor and the 4 inclined tensioning members in the rear portion of the motor;

• 2 straight tensioning members and 2 inclined tensioning members in the front portion of the motor; and 2 straight tensioning members and 2 inclined tensioning members in the rear portion of the motor, all of these located as opposite pairs;
the inclined tensioning members being positioned in any one of the described arrangements with an inclination selected among an inclination towards the center of the casing and an inclination towards the outside of the casing and always having one straight tensioning member and one inclined tensioning member in each one of the 4 longitudinal planes of the motor where the securing elements are located.
Motor-securing system, according to claim 1, characterized in that when there are 8 articulated and axially inclined tensioning members, the 4 tensioning members in the front portion of the motor are inclined in an opposite way to the 4 inclined tensioning members in the rear part of the motor.
Motor-securing system, according to claim 1, characterized in that the casing includes at least 4 omega profiles welded on its outer face, each one of which comprises at least two perforations in each one of which a cap has been welded, at least 4 omega profiles arranged in such a way that the perforations coincide with those made in the casing for the tensioning members to pass through and attach to the casing by means of the omega profiles, making the attachment more robust.
Motor-securing system, according to claim 2, characterized in that the straight tensioning members comprise a straight thread bar that is secured at one end to the securing element of the motor by means of a nut and a locknut and that is secured at the opposite end of the thread bar to the casing by means of a nut on the outer face of the casing and with a locknut on the inner face of the casing.
Motor-securing system, according to claim 1, characterized in that the articulated and axially inclined tensioning members comprise a first section of thread bar that articulates with a second section and that is connected to the casing on the end that is not articulated by means of a nut on the outer face of the casing and by means of a locknut on the inner face of the casing, a second section, that articulate on both ends with the first thread section and with a third thread section, and a third thread section that connects to the securing element of the motor by means of a nut and a locknut on the end that does not connect.
Motor-securing system, according to claim 6, characterized in that the articulated ends of the first and third section are flattened and have a threaded through hole to fit a fork into, located in each one of the connected ends of the second section.
Motor-securing system, according to claim 7, characterized in that the forks of the articulated ends of the second section comprise a threaded through hole in which each one of the flattened sections of the first and third section will be inserted and through which a thread stud is inserted for the attachment of the connection.
Motor-securing system, according to claim 8, characterized in that the studs that attach the connections, attach the connections by means of a nut and a locknut located one of each side of the fork.