FR2654272A3 - FILTER DEVICE FOR THE COOLING SYSTEM OF AN ELECTRIC MOTOR. - Google Patents

Abstract

The object of the invention is to provide low-maintenance yet safe operation of an electric motor in an atmosphere containing ink mist and dust. The electric motor (2) is equipped with a fan (3) preceded by a filter housing (1) in which chambers (4, 5 and 6) are formed. The inlet opening (10), the outlet opening (12) and passage openings (7, 8) between successive chambers are arranged so that the air flow created by the fan (3) undergo a change of direction in each of the chambers (4, 5, 6). One of the chambers (5) is enlarged by a dead space (5a) for the separation of dust. The invention is particularly applicable to the drive motors of rotary printing presses.

Description

The invention relates to a filter device

  for the cooling system of an electric motor

  motor, in particular of a drive motor on a rotary printing press, with a fan for supplying the electric motor with cooling air

  and a filter provided upstream of the fan.

  It is known to cover the opening of

  a fan to power an electric motor

  cooling air, simply by a grid in some cases, for the protection against accidental contact, and by a mat (tablecloth) filtering

  in other cases to purify the cooling air.

  When the suction opening is exclusively protected by a grid, the motor is strongly at risk

  to be damaged especially when operating at

  high erection and is used for training on a rotary printing press In the environment

  immediately of such a machine reigns an atmosphere of

  with a certain fraction of ink mists containing solvents The direct consequences in

  are the clogging of the meshes of the grid, the

  fan blade profile, clogging of the cooling channels provided in the electric motor and the risk of damage to the brushes by deposits on the collector of a DC motor, for example, especially the aforementioned phenomena occurring directly on the electric motor, are

  aggravated by a high operating temperature

  because, in this case, the solvent evaporates very quickly from a liquid film formed by the ink mist, which leads to the formation of a crust and,

  in the end, the clogging of cooling channels

  An indirect consequence is the consequent overheating of the motor as a result of

  insufficient cooling air.

  Although the risk of clogging cooling channels in the electric motor and damaging brushes by the mentioned use of filter mats is resisted, this advantage is obtained at the cost of frequent replacement of the filter mats, which, by their very nature are clogged even faster than grid meshes or, even more so, that cooling channels in the engine In particular

  when filter mats are used, simple monitoring

  engine temperature rush is not enough to get safe operation Instead, it takes

  perform an expensive measurement of a different pressure

  to maintain a sufficient amount of cooling air when the electric motor is continuously

  of warming up, since an exact measure of the temperature

ture on the engine is difficult.

  For cooling electrical distribution equipment cabinets, enclosures containing electronics or the like to be

  ventilated during operation while maintaining them

  Being protected from dust and foreign bodies, it is known to mount a labyrinth filter in front of a fan supplying such an apparatus with cooling air, which filter is essentially divided in two and consists of a part lower and upper parts which can be separated from one another and provided with comb-like lamellae

  and interlocking with one another (German patent

3, No. 34 23 047).

  With such a filter, the degree of pollution given by the cooling air must be taken into account.

  through the filter, by the proper choice of space-

  the number and slope of the different lamellae facing each other In the case of heavy pollution, efforts should be made, at the very least, to incorporate a relatively large number of lamellae. to be exercised on the result of the purification by the proper choice of the slope of the lamellae, leads, that if the degree of pollution is important, an attempt is also made to give as great an inclination as possible to the lamellae relative to the bottom and lid of the labyrinth filter housing, if possible in addition so that the free ends of the lamellae are directed towards 0 o the gold inlet opening, these two measures considerably increase the loss of charge in the filter, so the fan must have a capacity

  relatively large suction to obtain an

  The same applies if, in order to adapt to the degree of pollution of the cooling air, a distance of

small between the slats.

  The object of the invention is to ensure the func-

  an electric motor with low maintenance,

  so that it is nevertheless safe and with a

  energy as low as possible.

  For this purpose, according to the invention, a filtering device as defined at the beginning is characterized in that it comprises a filter housing whose interior is partitioned by partitions into an air inlet chamber, an interconnected intermediate chamber. through a first passage opening to the air inlet chamber, and an air outlet chamber connected through a second passage opening to the intermediate chamber, the first passage opening, the second opening of the air inlet chamber, passage, an inlet opening provided in a first wall of the filter housing, an outlet opening provided in a second wall of the filter housing, and the partitions are arranged such that a flow of air, created by the fan penetrating through the intake opening

  in the air inlet chamber and exiting through the

  exit of the air outlet chamber, is subjected to a change of direction in the intermediate chamber and in the air outlet chamber, the change of direction in at least the intermediate chamber corresponding essentially to a reversal of the direction flow, and

  part of the intermediate chamber

  both the first passage opening and the second passage opening, is connected, in the direction of the first wall of the housing, a part of the chamber

  intermediate forming a dead space.

  With the filter device according to the invention, there is obtained a certain separation of the dust

  flying and dust or flock of paper

  which are not harmful to the electric motor -

  cooling air polluted by such

  and an ink mist. An essential advantage

  This is because the ink mist, separated from such cooling air and retained in the filtering device, can have no detrimental effect.

on the engine.

  The ink mist is retained in the filter device because it is precipitated in particular on walls forming impact surfaces and on wall or wall surfaces located near an outer path of a curved portion of the filter. air flow Precipitation is produced on a partition forming an impact surface as a result of the retaining effect thereof and, on a partition surface located near an outer path of a curved portion of the current of air, as a result of centrifugal forces acting on ink droplets of the

  ink mist contained in the cooling air

ment.

  In this way, we already obtain a separa-

  between, on the one hand, ink mists held in the filter device and, on the other hand, flying dust and paper wad some of which then passes through the electric motor more or less unhindered. the filtering device

  according to the invention not only retains scrambles

  In this respect, it is also advantageous that the fog retained on the one hand and the dust retained on the other hand,

  are essentially deposited in different places.

  In fact, while a precipitation of

  Ink blot occurs in the manner described above on some surfaces of partitions or walls of

  chambers, an essential part of the dust

  The cooling air accumulates in a part of the intermediate chamber forming a dead space, in which a quiet flow zone is established. Another part of the dust is captured in the precipitated ink mist. The filter housing thus also considerably reduces the load of the electric motor by the dust. A filter device according to the invention also has the advantage that a simple monitoring is sufficient

  engine temperature to monitor the cooling

  loss of it, even in the case of electric motors operated near their maximum power,

  therefore operating at a relatively high temperature.

  Such a monitoring method could be risky for an electric motor thus operated if the intervals until the maximum permissible temperature is reached, as a result of clogging of filter mat by

  for example, were relatively short.

  The filter device according to the invention serves at the same time as a protection against accidental contact, so that a protective grille can not be dispensed with for the suction opening of the fan.

  In addition, the flow sections of the

  filtering device according to the invention can be rendered if

  large, without the need for special expenditure.

  that a cooling air flow rate is

  high and a relatively small pressure loss

in the device.

  One embodiment of the filter device according to the invention is characterized in that the second passage opening and the outlet opening are arranged relative to one another so that it occurs in the outlet chamber. air also a change of direction corresponding essentially to a reversal of the direction of flow, just as, following this inversion, an additional deviation

of the air stream.

  This embodiment represents an optimum

  in that the centrifugal forces generated during the reversal of the flow direction of the air stream into the air outlet chamber cause precipitation of ink droplets as the air stream still contains after the passage of the intermediate chamber and in that the consequent deviation of the air flow produces a

again a similar effect.

  Another embodiment is characterized in that the air chamber, the intermediate chamber and the air outlet outlet are arranged in such a way that the air stream is guided between parallel side walls of the filter housing, which the changes of direction are made in vertical planes and that the air inlet chamber is located above the

intermediate room.

  Thus, we further promote, by gravity

  The precipitation of ink droplets in the intermediate chamber especially, and the air inlet chamber, the intermediate chamber and the air outlet chamber can be formed in a particularly simple manner, as explained in more detail in FIG. what will follow. To increase centrifugal forces

  mentioned and thus to further improve the

  of ink droplets, another characteristic

  of the invention provides that the first passage opening has a smaller cross section than

the admission opening.

  In addition, a particular structure is obtained.

  simply a filter device according to the invention

using flat partitions.

  However, the precipitation of ink droplets on the partitions is promoted by one embodiment of the filter device according to the invention, which is characterized by the provision of curved partitions to form the air inlet chamber and the air chamber.

  outlets, which partitions favor the changes

  direction of the air flow.

  Since it is advantageous to be able to

  to kill without much difficulty the maintenance work required

  after obtaining by the invention of a function-

  Although a low-maintenance electric motor is required, even though the intervals between the interviews are very long, another feature is that a side wall of the filter housing is removably connected to this housing. In combination with the arrangement described above of the air inlet chamber, the chamber

  intermediate and air outlet chamber, pro-

  a guide of the air flow between the parallel side walls of the filter housing, the connection

  removable side wall allows easy access-

  the entire interior of the housing, from which the deposits of ink and dust,

  so that the interview is very easy.

  A further improvement in serviceability is obtained by an embodiment which is characterized in that a lower part of a

  side wall of the filter housing has an opening

  normally formed by the front of a drawer that

we can extract from the case.

  In combination with a side wall

  of the filter housing, it thus becomes possible to easily remove the accumulated dust and ink deposits, possibly detached by

  scraping and that can be gathered in the drawer.

  Other features and benefits of

  the invention will become clearer from the description of

  The following description of several nonlimiting exemplary embodiments, as well as the appended drawings, in which:

  l Figure 1 is a simplified overview of

  fice an electric motor equipped with a fan and a filter device according to the invention upstream of the fan, the filter housing being shown in section;

  FIG. 2 is a simplified representation

  a filter device according to the invention with partitions whose conformation differs from those according to Figure 1; and FIG. 3 is a partial section taken along the line III-III of the filter device of FIG.

figure 1.

  Figure 1 shows an example embodiment

  according to which a filter housing 1 connects directly

  to a fan 3 surmounting an electric motor

  The filter housing is divided into an inlet chamber 4, an intermediate chamber 5 and a

  air outlet chamber 6 The entrance chamber 4

  with the intermediate chamber 5 by a first

  opening 7, and the outlet chamber 6

  with the intermediate chamber 5 by a second passage opening 8 An inlet opening 10 is

  provided in a first wall of the housing, and an opening

  12 is provided in a second wall of the housing The first wall is a first transverse wall 9 and the second is a second transverse wall 11, located opposite the first, the filter housing 1 The fan 3, is connecting directly to the outlet opening 12, creates during its

  a flow of air entering through the opening

  intake 10 in the inlet chamber 4 and out

  through the outlet opening 12 of the outlet chamber 6.

  On its way through the filter housing 1, this air stream undergoes a change of direction in each of the chambers formed by the air inlet chamber 4, the intermediate chamber 5 and the air outlet chamber 6 The change of direction in the inlet chamber 4, indicated by an arrow 13, is imposed by the relative provision of the opening

  inlet 10 and first passage opening 7.

  In the example discussed here, the sections of the inlet opening 10 and the first through opening 7 are located in substantially perpendicular planes. A first partition 14 for the subdivision of the interior of the filter housing 1 constitutes a rear delimitation of the inlet chamber 4 and an impact surface for the air flow inside this chamber. the air inlet 4 is further delimited by an anterior section 15 directed towards the inlet opening 10 of a third transverse wall 15, as well as by a second partition 16 situated opposite the third transverse wall 15 and in which is also formed the first

passage opening 7.

  The second partition 16 at the same time forms a delimitation of the intermediate chamber 15 which follows the air inlet chamber 4 and is delimited further by

  a section 9a connecting to the second partition 16 -

  of the first transverse wall 9 of the filter housing

  1, by a third partition 17 constituting a delimitation

  ta-ion rear of the intermediate chamber, and an anterior section 18a, extending from the first transverse wall 9 to the third partition 17, a

  fourth transverse wall 18 of the filter housing 1.

  A rear portion 5b of the intermediate chamber 5 has the second passage opening 8 next to the first passage opening 7; the two sections of

  these openings are preferably located

  in one and the same plane, but at least in substantially parallel planes Thus, it imposes the flow of air in the rear part 5b of the chamber

  intermediate 5 a change of direction corresponding to

  substantially causes a reversal of the direction of flow of the air entering through the first passage opening 7 and out through the second passage opening 8 under the action of centrifugal forces acting thereby on the ink droplets of an ink mist contained in the air stream, these rods are precipitated especially on a portion of the anterior section 18a of the fourth transverse wall 18 located opposite the first 7 and second passage openings 8 With it prediction of the latter in the rear part 5 b

  of the intermediate chamber 5, so close to

  diate of the third partition 17, which delimits the intermediate chamber 5 at the rear, a precipitation of ink droplets also occurs, especially on the third partition 17 This is due in part to the centrifugal forces mentioned and partly to the action of the third partition 17 as an impact surface. At the rear portion 5b is connected a front portion 5a of the intermediate chamber which extends towards the first wall of the housing, constituting the first transverse wall 9 By this front part a, a dead space has been created in the Intermediate Chamber 5, space in which is essentially established

  a vortex indicated by the arrow 19.

  Although the zone where this vortex 19 is established, it must be considered as a flow zone

  tranquilized compared to the current of air passing through

  In the case of the filter housing 1, the centrifugal forces mentioned here also produce some precipitation of ink droplets. However, a large part of the dust entrained in the air stream is separated at the same time in this zone.

calm flow.

  The second passage opening 8 is situated in the rear part 5b of the intermediate chamber and at the same time in the front part 6a of the air outlet chamber 6. The first partition 14 constitutes a

  previous delimitation of this front part 6 a.

  This is followed by a rear portion 6b forming an enlargement delimited at the front by the third partition 17 The air outlet chamber 6 is delimited

  in addition, by a posterior section 15b of the third

  sth transverse wall 15, a rear section 18b of the fourth transverse wall 18, and the second transverse wall 11 The planes of the second through opening 8 and the outlet opening 12 are located in substantially perpendicular planes Moreover, the outlet opening, provided in the second transverse wall 11, is located behind the third partition 17 to the air flow in the outlet chamber 6 is thus imposed a change of direction substantially corresponding to a reversal of the

  direction of flow followed by additional deviation.

  The first partition 14, the second partition 16 and the third partition 17 each extend from a first removable side wall 20 to a second

  side wall 20 '(not visible in FIG.

  lends to the first of the filter housing 1, both

  side walls 20 and 20 'being oriented vertically

  A horizontal arrangement of these walls is

  however conceivable also within the framework of

  By the aforementioned coordination of the partitions and the side walls, the extremely simple division already mentioned in the foregoing from the inside of the filter housing 1 is obtained in the air inlet chamber 4, the intermediate chamber 5 and the outlet chamber As has been mentioned, it is advantageous for the inlet chamber 4 to be located above the intermediate chamber 5. The passage openings 7 and 8 are also extremely simple in shape since they are delimited by the first side wall 20 and the opposite side wall 20 'and, on the one hand, by a free edge of the second partition 16 or the third partition 17 and, on the other hand,

  on the other hand, by a free edge of the first partition 14.

  Compared to a very simple configuration illustrated in FIG. 1 of the flat partition 14, FIG. 2 shows an embodiment in which the contours of the upper boundaries of the inlet 4 and outlet 6 chambers are adapted to the changes in direction of the current. In place of the first partition 14 illustrated in FIG. 1, curved guide surfaces 21 and 22 constituted by, for example, partitions 26, 27 in the form of a guide, are provided in this case according to FIG. sheet baffles having adequate curvature and placed between the walls

laterals 20 and 20 '.

  In order to allow the easy removal already mentioned of the deposits of the filter housing, the lower part of the side wall 20 'according to Figure 2 has an opening normally closed by the front of a drawer 23 that can be extracted from the housing of

filter 1.

  FIG. 3 shows a removable arrangement of a side wall 20. For this purpose, the lower end of the side wall is provided with flanged tabs 24 which are inserted in corresponding slots of a raised edge of the fourth transverse wall 18. while the upper end of the

  side wall 20 is provided with a lock 25.

Claims (7)

  1 Filtering device for the heating system   cooling of an electric motor, in particular of a drive motor on a rotary printing press, with a fan for supplying the electric motor with cooling air and a filter provided upstream of the fan, characterized in that it comprises a filter housing (1) whose interior is partitioned by partitions (14, 16, 17, 26, 27) in   an air inlet chamber (4), an intermediate chamber   diary (5) connected through a first passage opening (7) to the air inlet chamber (4) and an air outlet chamber (6) connected through a second passage opening ( 8) to the intermediate chamber (5), the first passage opening (7), the second passage opening (8), an inlet opening (10) provided in a first wall (9) of the filter housing (1). ), an outlet opening (12) provided in a second wall (11) of the filter housing (1), and the partitions (14, 16, 17, 26, 27) are arranged in such a way that a current of air, created by the fan (3), penetrating through the inlet opening (10) into the air inlet chamber (4) and exiting through the outlet opening (12) of the outlet chamber air (6), is subjected to a change of direction in the intermediate chamber (5) and in the air outlet chamber (6), the change of direction in at least the intermediate chamber (5) corresponds to essentially reverses the direction of flow, and a portion (5b) of the intermediate chamber (5) having the first passage opening (7) and the second passage opening (8) is connected in the direction of flow. of the first wall (9) of the housing, a portion (5a) of the intermediate chamber (5) forming a dead space.   Filter device according to Claim 1, characterized in that the second passage opening (8) and the outlet opening (12) are arranged relative to one another so as to occur in the chamber. air outlet (6) also a change   direction corresponding essentially to an inversion   the direction of flow, as well as, following this inversion, a further deflection of the air flow. Filtration device according to Claim 1, characterized in that the air chamber (4), the intermediate chamber (5) and the air outlet chamber (6) are arranged in such a way that the flow of air is guided. between parallel side walls (20, 20 ') of the filter housing (1), that changes of direction take place in vertical planes, and that the air inlet chamber (41 is located above bedroom intermediate (5).   4 filter device according to claim 1, characterized in that the first passage opening   (7) has a smaller cross-section than the opening intake (10).   5 filter device according to claim 1, characterized in that it comprises planar partitions (14, 17).   Filter device according to Claim 1, characterized in that curved partitions (26, 27) are provided for the formation of the inlet chamber (4) and the air outlet chamber (6). the   changes of direction of the air flow.   Filter device according to claim 3, characterized in that a side wall (20) of the filter housing (1) is detachably connected to this housing (18).   Claims 1 to 7, characterized in that a part   lower side wall (20 ') of the filter housing (1) has an opening normally closed by the front of a drawer (23) which can be removed from the filter housing (1).