DESCRIPTION

The present invention relates to an integrated apparatus for the simultaneous control and operation of a pump for recirculating the cooling fluid of a vehicle and a fan for cooling the said fluid .

It is known in the sector for the production of engines that there exists the need to cool said engines by means of recirculation of a cooling fluid which is conveyed by means of a corresponding recirculation pump, the impeller of which is operated by a shaft driven by movement transmission means for example consisting of a pulley and a belt connected to the shaft of the combustion engine. It is also known that the recirculation of the cooling fluid must be performed at a rate which corresponds to the actual cooling requirement determined by the real conditions of use and by the external temperature so as to avoid the constant and unnecessary operation of devices which draw upon useful power increasing the consumption levels of the vehicle.

In addition it is also required that the rotation of the fan which forces air for cooling the said cooling fluid should be controlled in a similar manner .

Also known are devices for controlling the said rotational movements, which actuate a spindle common to the pump impeller and the cooling fan; these devices, although fulfilling their function, do not envisage however the possibility of defining a sufficient number of different rotational speeds of the two parts and in particular do not envisage an idle condition of at least one of the two parts, said condition being instead necessary for all uses in periods of cold weather when cooling is not necessary and, on the contrary, would reduce the efficiency of the engine.

These results are obtained according to the present invention by an integrated apparatus for simultaneous control and operation of a fan and a pump of vehicles according to the characteristic features of Claim 1 and a pump unit according to Claim 15.

The integrated apparatus comprises in combination a first friction coupling comprising a driving part for transmitting a rotational movement having means suitable for connection to the vehicle engine for receiving the rotational movement, and an eddy current or Foucault coupling operated by the first friction coupling; the first coupling and the eddy current or Foucault coupling being configured for three-speed rotational operation of the fan; and a second ON/OFF friction coupling for rotationally operating or stopping the pump impeller, said second coupling comprising a wrap spring for connecting the driving part for transmitting the movement to a driven part suitable for connection to the pump shaft.

The driving part comprises preferably a single rotor for transmitting the movement respectively to the driven part of the second coupling and to a driven part of the first coupling.

The rotor may comprise an axial extension elongated towards a front part of the apparatus and provided with an annular edge, a support for connection to the fan being mounted on the axial extension. Preferably, the rotor is in the form of an "overturned E".

Preferably the means for receiving the rotational movement comprise a radially outer axial extension of the rotor formed in the manner of a pulley.

According to a preferred embodiment the apparatus comprises a bearing on which the rotor is mounted, the bearing being configured to be mounted on the pump body such that the rotor is supported idle on the pump body.

The first coupling (300) preferably comprises a fixed first electromagnet inserted inside a first seat of the rotor; a first armature arranged in a position radially coinciding with the electromagnet and axially on the opposite side to the rotor and connected to the support of the fan by means of an elastic membrane; a second armature radially more inner with respect to the first armature and connected by means of a further elastic membrane to a flange mounted idle, via a bearing, on the axial extension of the rotor.

The Foucault coupling may comprise a driving part with permanent magnets fastened to said flange and a driven part consisting of electrical conducting elements inserted in the support of the fan.

According to a preferred configuration the second coupling comprises a second electromagnet extending axially towards the front part and designed to remain, during use, fixed relative to the body of the pump, an associated armature axially arranged on the front side of the electromagnet, and a flange fastened to the annular edge of the axial extension of the rotor from which it receives movement .

The armature of the second coupling may be fastened to a cup member, with an open bottom end, displaceable in both senses of the axial direction and connected to a first end of the wrap spring, the other end thereof being fastened onto a hub integral during use with the pump shaft.

Preferably the wrap spring is kept in position by a bush which has, axially force-fitted inside it, an axial tooth of a flange fastened by screw means to the annular edge of the axial extension of the rotor. The apparatus may comprise a ring, one end of which is rigidly connected to the hub and the other end of which forms the guide for axial sliding of the cup member and the armature towards/away from the magnet.

Preferably, the second coupling comprises an axial spring arranged between a stop surface formed at the rear end of the ring and the cup member and stressed so as to push against the latter and therefore the armature integral therewith.

The integrated pump unit according to the invention comprises a body, a shaft and an impeller of the pump and a support for connection to a cooling fan; and is characterized in that it comprises an apparatus according to the invention.

Preferably the first and second friction coupling and the eddy current or Foucault coupling are mounted on the pump body.

Greater details may be obtained from the following description of a non-limiting example of embodiment of the subject of the present invention provided with reference to the attached drawings in which: Figure 1 : shows a view cross-sectioned along an axial vertical plane of an embodiment of the apparatus according to the present invention;

Figure 2 : shows a view on a larger scale of the details of the second friction coupling; and

Figure 3: shows a view on a larger scale of a variation of embodiment of the second friction coupling .

As shown in Fig. 1 and assuming solely for the sake of easier description and without a limiting meaning a pair of reference axes in the longitudinal/axial direction X-X and transverse/radial direction Y-Y as well as a front part corresponding to the part for connection to the cooling fan and a rear part opposite to the front part, the impeller 101 of a pump 100 for recirculating the cooling fluid of vehicles and the like is mounted on a first end of a shaft 103 supported by a fixed assembly 10 comprising the body 102 of the pump rigidly connected to the base 10 of the vehicle engine.

A sealing gasket 103b is also fitted onto the shaft 103 and is arranged on the rear part of said shaft

103.

At the end opposite to that of the impeller 101 there is also a fan 220 designed to force air onto the radiator (not shown) containing the fluid moved by the pump 100 so as to obtain cooling of the said fluid .

The integrated control and operating apparatus according to the present invention is arranged between the impeller 101 of the pump, the blades 201 of the cooling fan 200 and the movement generating means schematically shown as a belt 3 connected to the shaft of the combustion engine (not shown) and comprises essentially a first friction coupling 300 and a second friction coupling 400 and an eddy current or Foucault coupling 500 operated by the first friction coupling 300.

Said fan 200 is schematically shown with its blades 201 and a support 202 mounted on an axial extension 315 of the rotor 310 of the first coupling 300 via a bearing 202a so as to be idle with respect to the said rotor; the axial extension is axially elongated towards the front part A of the apparatus .

The axial extension comprises a coaxial annular edge 315 extending radially outwards.

In greater detail:

- the first friction coupling 300 comprises:

-- a rotor 310 mounted idle on the body 102 of the pump via a bearing 310a; the rotor 310 is in the form of an "overturned E" and has a radially outer axial extension 311 formed in the manner of a pulley 311a designed for coupling with said belt 3 for transmitting the movement received from a shaft connected to / coinciding with the vehicle driving shaft .

The rotor 310 also has axial openings 312 designed to interrupt the flux lines of the electromagnet field in order to force them along preferential paths as will become clearer below.

The first friction coupling 300 further comprises: a first electromagnet 3200 fixed to the pump body in turn fastened to the base 10 and inserted inside a first seat 313 of the rotor 310; the electromagnet 320 is preferably formed by two independent windings for causing excitation of the electromagnet at different values of the current supplied;

-- a first armature 321 arranged in a position radially coinciding with the electromagnet and axially on the opposite side to the rotor 310; the armature 321 is connected to the support 202 of the fan 200 by means of an elastic membrane 321a which, being elastically deformable in the axial direction, but radially rigid, allows axial displacement of the armature 321 towards/away from the rotor 310, but prevents relative rotation with respect to the support 202 of the fan;

-- a second armature 322 which is radially more inner with respect to the first armature is connected by means of a further elastic member 322a to a flange 510 mounted idle via a bearing 510a on the axial extension 315 of the rotor 310 on which the support 202 of the fan is mounted; the axial extension is elongated towards the front part A of the apparatus and is provided with an annular edge 315a;

-- the flange 510 forms the support for permanent magnets 511 forming the first part of the Foucault coupling 500, the other part of which is formed by conducting members 512 inserted in the support 202 of the fan.

the second coupling 400 is of the ON/OFF type and comprises in turn

a second electromagnet 410 (Fig. 2) extending axially towards the front part A and fixed to the body 102 of the pump 100, and a corresponding armature 420 axially arranged on the front A of the electromagnet 410;

the armature 420 is displaceable in both senses of the axial direction X-X together with a cup member, with an open bottom end, to which it is fastened; the cup member 450 (Fig. 2) is connected to a first end 452a of a wrap spring 452, the other end 452a of which is fixed onto a hub 453 rigidly connected to the shaft 103 of the pump 100;

the wrap spring is positioned on a bush 454 which has axially force-fitted inside it, an axial tooth 455a of a flange 455 fastened by screw means 455b to the annular edge 315a of the axial extension 315 of the rotor 310 of the first coupling 300; the flange 455 supports friction material 455c in a radial position corresponding to that of the armature 420;

preferably it is envisaged that a ring 456 is arranged on the outside of the wrap spring 452 and concentrically therewith, one end 465a of said ring being rigidly connected to the hub 453 and the other end 456b thereof forming the guide for axial sliding of the cup member 450 and the armature 410 towards/away from the magnet 410 in order to keep the said cup member 450 and armature 420 concentrically centred.

With this configuration the integrated apparatus according to the invention is able to control and operate both the fan 200 and the pump 100 as follows :

FAN

a) with first electromagnet 300 deactivated both the respective armatures 321, 322 are detached from the rotor 310 operated by the pulley 3 and the fan consequently remains in the idle condition; bl) by energizing the first electromagnet 320 with a first amount of current the second armature 322 is recalled against the rotor 310, causing rotation of the driving part 510 of the Foucault coupling 500 which, transmitting the movement without contact, introduces a relative slipping of the driving part 510 and the driven part 512, resulting in a lower speed of the fan compared to that of the rotor 310 as a result of the dimensional characteristics of the said coupling 500;

b2) by energizing the first electromagnet 320 with a second amount of current greater than the first amount both the armatures 321,322 are recalled against the rotor 310, resulting in rotation of the fan 200 with a speed of rotation equal to that of the said rotor 310;

PUMP

at the same time two further controlling and operating operations of the shaft 103 of the pump 100 may be carried out:

dl) in conditions where the electromagnet 410 is de-energized, the armature 420 is free to keep its axial position towards the flange 455, coming into contact with the friction material 455c; the flange is rotated so that it rotates together with the rotor 310 to which it is fastened by means of the axial extension 315;

in this condition the cup member 450 is in turn displaced towards the flange 455 and, rotating together with the armature 420 in a predefined direction, rotationally drives the end 452a of the spring 452, causing it to grip on the hub 454 and thus rotationally constraining the driving part (rotor + flange) together with the driven part (cup member + hub) so as to cause rotation of the shaft 103 of the pump for operation of the impeller and recirculation of the fluid;

d2 ) in conditions where the electromagnet 410 is energized, the armature 420 is recalled against the said electromagnet 410, being disengaged from the flange 455; during displacement towards the rear part P the armature drives the cup member 450 which, slackening the turns of the spring, disengages the driving bush 454 and therefore the driven hub 453 which remains in the idle condition together with the shaft 103 of the pump 100.

As shown in Fig. 3 it is envisaged that the second coupling 400 is actuated according to a variation of embodiment which comprises an axial spring 470 arranged between the cup member 450 and a stop surface 456c formed at the rear end of the ring 456; the spring is tensioned so as to press against the cup member and therefore the armature integral therewith.

In conditions where the electromagnet is de- energized the spring helps keep the armature pressed against the driving flange 455, causing rotation of the pump shaft; in conditions where the electromagnet is energized, said electromagnet recalls the armature and therefore the cup member, overcoming the thrusting force of the spring, resulting in the idle condition of the pump shaft as already mentioned above.

It is therefore clear how with the integrated apparatus according to the invention for controlling and operating the fan and the pump of a vehicle it is possible to obtain five speeds of rotation distributed between the fan and the pump and in particular an idle condition of the fan and/or pump.

In addition, as a result of the particular configuration of the pump coupling, it is possible to obtain a fail-safe operating mode since, in the event of an electrical failure, the armature of the second coupling remains in contact with the friction material of the flange connected to the rotor and consequently the pump always remains mechanically operative.

It is also pointed out how the two couplings, i.e. the fan coupling and the pump coupling, use a single rotor, allowing a reduction of the component parts, costs and both axial and radial dimensions of the assembly.

Although described in connection with a number of embodiments and a number of preferred examples of implementation of the invention, it is understood that the scope of protection of the present patent is determined solely by the claims below.