Double-bearing support group for a fan for cooling vehicles

Abstract

Support group (100) for supporting a fan (101) for cooling the engine of a vehicle, comprising a coupling (102) for coupling with the fan (101), a rotor (104) designed to rotate about a longitudinal axis (AV) so as to rotationally drive the coupling, and a support (106); the support comprises a base (106) rigidly fastened to a fixed part of the engine and an axial extension (106a) extending projecting from the base towards the coupling (102) for coupling with the fan (101). Wherein the group further comprises a first bearing (105a) keyed onto the axial extension (106a) of the support, in a position proximal to the base (106) and distal, in use, from the coupling (102) and a second bearing (105b) keyed onto the axial extension (106a) of the support in a position proximal to the coupling. The rotor (104) is coaxially mounted on the axial extension of the support and comprises a first section (104a), axially distal from the coupling (102) and keyed onto the outer ring of the said first bearing (105a), and a second section (104b) which extends axially and an end part of which, distal from the base, is mounted on the second bearing (105b) and coupled to the coupling for coupling with the fan.

Description

[0001] DOUBLE-BEARING SUPPORT GROUP FOR A FAN FOR COOLING VEHICLES

[0002] DESCRIPTION

[0003] The present invention relates to a support group for supporting a fan for cooling the engine of a vehicle and to an assembly comprising a rotating drive shaft, a damper and the support group.

[0004] It is known, in the technical sector relating to internal-combustion engines for automotive vehicles, that there exists the need to associate said engines with devices for dissipating the heat generated during operation.

[0005] As shown in Figure 1, relating to the state of the prior art, said devices include a fan 1 which is designed to force air towards the engine or a radiator and is mounted on a support 3 connected to a pulley 4 for taking up the movement from the drive shaft, mounted on a bearing 5 keyed onto a support 6 fastened to the fixed base of the engine. The support 3 is coupled at the front to a viscostatic coupling 2 or the like which is axially arranged between the fan 1 and the support 3 connected to the pulley and performs variable rotational coupling of the pulley 4 and the fan 1.

[0006] In the known configuration, the movement take-up pulley 4 for driving the fan 1 is moved by a further pulley 10 moved by the drive shaft 11, there being arranged between the drive shaft and the pulley 10 a damper 12 designed to absorb and dampen the torsional stresses generated by the internalcombustion engine.

[0007] In general terms, the damper 12 may be in the form of a large-diameter disc with which a pulley may be combined if required.

[0008] Owing to the small volumes available in the engine compartment, it is envisaged that the fan axis AV is offset with respect to the engine axis AM and that the bearing 5 which supports the movement take-up pulley 4 is located in the zone of the pulley 4 itself, being designed with dimensions depending on the space available.

[0009] In the arrangement shown in Fig. 1 , the support 3 which supports the viscostatic coupling 2 is therefore fixed to the pulley 4 in a position axially upstream of the damper 12 (namely proximal to the base 6 and distal from the fan 1) and the bearing 5 is also upstream of the damper 12. The support 3 is also arranged axially upstream of the viscostatic coupling 2. With this configuration, the bearing 5 must support the loads resulting both from the belt pulling force for driving the fan and from the projecting weight of the fan assembly and the viscostatic coupling.

[0010] It happens, however, that the more recent generations of internalcombustion engines need to dispose of increasingly greater amounts of heat, which results in the need for a significant increase in the dimensions of the fan and the associated viscostatic coupling associated with it, which results in a consequent increase in the loads acting on the bearing 5 which, being subject to greater stress, has a shorter working life, thus requiring costly replacement, with the consequent costs and machine downtime.

[0011] The technical problem which is posed, therefore, is that of providing a support group for supporting cooling fans of vehicle engines which is able to provide a solution to the aforementioned drawbacks of the prior art in order to obtain a longer working life of the said group.

[0012] In connection with this problem it is also required that this support group should be easy and inexpensive to produce and assemble and have a low weight.

[0013] These results are obtained according to the present invention by a support group for supporting a fan according to the features of Claim 1.

[0014] According to a first aspect, the invention therefore relates to a support group for supporting a cooling fan for the engine of a vehicle, comprising a connection coupling for coupling with the fan, a support and a rotor designed to rotate about a longitudinal axis so as to rotationally drive the coupling, which coupling performs a variable rotational coupling together of the rotor and fan.

[0015] The support comprises a base designed to be rigidly fastened to a fixed part of the engine and an axial extension extending cantilevered from the base to an end situated proximal to the coupling for coupling with the fan.

[0016] A first bearing is keyed onto the axial extension of the support, in a position proximal to the base and distal, in use, from the coupling, and a second bearing is keyed onto the axial extension of the support in a position proximal to the coupling. The rotor is coaxially mounted on the axial extension of the support and comprises a first section, axially distal from the coupling and mounted on the outer ring of the said first bearing, and a second section which extends axially and has a terminal end part, distal from the base, coupled to the coupling for coupling with the fan. The first section of the rotor may comprise an element for taking up the rotational movement, designed to be connected to movement generating means driven by a drive shaft; said movement take-up element is preferably in the form of a pulley.

[0017] The support group also has a connection piece which is rigidly connected to the terminal end part of the second section of the rotor and connects the rotor to the coupling; the connection piece is connected axially downstream of the rotor and axially upstream of the connection coupling and is therefore axially situated between said terminal end part of the rotor and the connection coupling. Said connection piece is preferably in the form of a cover fastened to the end part of the second rotor section by fastening means.

[0018] According to the invention, the terminal end part distal from the base and / or the connection piece is / are mounted on the second bearing.

[0019] Further preferred embodiments are described in the dependent claims which are herein incorporated in their entirety.

[0020] The present invention relates furthermore to an assembly comprising a drive shaft assembly, a damper and a support group according to the attached claims.

[0021] Further details may be obtained from the following description of a nonlimiting example of embodiment of the subject of the present invention provided with reference to the attached drawings in which:

[0022] Figure 1 : shows a partially sectioned view of a fan support group according to the prior art; and

[0023] Figure 2: shows a partially sectioned view of a fan support group according to the present invention.

[0024] As shown in Fig. 2 and assuming solely for the purposes of easier description a pair of reference axes, namely a longitudinal axis X-X coinciding with or parallel to the fan axis AV and a transverse / radial axis Y-Y perpendicular to the preceding axis, a preferred example of embodiment of the support group 100 for supporting a fan 101 according to the invention is connected to a viscostatic coupling 102 coupled with the fan 101 and comprises a fixed support which includes a base 106 designed to be rigidly fastened to fixed parts of the engine or engine compartment, and an extension 106a extending in the longitudinal / axial direction X-X towards a distal end facing, during use, the fan 101. A first bearing 105a is keyed onto the axial extension 106a of the base 106, in a position proximal to the base 160 and distal from the coupling 102 and therefore the fan 101.

[0025] A second bearing 105b is keyed onto the axial extension 106a in a position distal from the base and, in use, proximal to its end facing the fan.

[0026] A rotor 104 is coaxially mounted on the extension 106a of the support and is designed to rotate about a longitudinal axis, in the example coinciding with the axis of rotation AV of the fan 101.

[0027] The rotor 104 comprises:

[0028] -- a first section 104a axially distal from the fan 101, keyed onto the outer ring of said first bearing 105a and comprising means for taking up the movement, in the example consisting of a pulley;

[0029] -- a second section 104a extending axially from the first section 104 towards the coupling 102 and the fan 101 and having a terminal end part 104b1, axially proximal to the coupling 102, which is mounted on the second bearing 105b.

[0030] The rotor 104 is designed to be rotationally driven by means of the pulley of the first section 104a which may be connected, by means of a belt, to a pulley for generating the movement, driven by the drive shaft.

[0031] A connection piece 107 is rigidly connected to the terminal end of the second section 104b and designed to connect the rotor 104 to the viscostatic coupling 102. The connection piece 107 is in particular coaxial with the rotor and is for example in the form of a cover fastened to the end part of the second rotor section 104b by fixing means.

[0032] The presence of two bearings 105a, 105b spaced from each other in the longitudinal axial direction allows the loads acting on the support group to be divided up so that the first bearing 105a supports mainly the belt pulling force, while the second bearing supports mainly the overall cantilevered weight of the viscostatic coupling 102 and of the fan 101, thus reducing the load acting on the bearings and therefore their wear, while increasing the duration over time of the group, with a consequent reduction in the maintenance operations, thus favouring lower costs and the efficiency of the engine.

[0033] In the arrangement shown in Fig. 2, the support for connection to the coupling 102 is fixed to the rotor 104 in a position axially downstream of the damper 112. The first bearing is arranged in a position axially upstream of the damper 112, while the second bearing is arranged axially downstream of the said damper 112.

[0034] Owing to the particular configuration and dimensional design of the support with base 106 and axial extension 106a it is moreover possible to keep unchanged the axial position of the viscostatic coupling and the interaxial distance between the fan axis AV and engine axis AM, allowing housing of the damper 112 and any pulley integral therewith (not always present). Advantageously, the arrangement of drive shaft, damper 112 and fan support group according to the present description does not require structural modifications of the engine compartment and the various devices housed therein.

[0035] Furthermore, in the preferred embodiment shown, the rotor 104 has a cross- sectional form in which the first section 104a is formed with a radially outer axial arm 104a1 formed as the movement take-up element such as a pulley, a radially inner axial arm 104a2, which is fastened to the outer race of the first bearing 105a, and a radial arm 104a3 extending from the outer axial arm towards the axis of rotation AV. The radial arm connects together the two axial arms and has a radially inner end connected to the second section 104b of the rotor.

[0036] The second section 104b has said terminal end part, which is formed as an axial end arm 104b1 proximal to the coupling 102, and an axial arm 104b2 which is distal from the coupling 102 and connected to the first rotor section 104a, in particular to said radially inner end of the radial arm 104a3. Preferably, the distal axial arm 104b2 is arranged radially internally with respect to the end arm 104b1 proximal to the coupling. In this preferred embodiment, a radial arm 104b3 extending from the end arm towards the axis of rotation connects together the two axial arms 104b1,104b2.

[0037] This configuration advantageously allows further radial space to be gained between the first and second bearings, allowing the housing of larger-size auxiliary elements, such as the damper 112.

[0038] In alternative embodiments, the connection piece 107 could be mounted on the second bearing 105b, or the second bearing 105b could be arranged in an axial position such that both the terminal end part of the second rotor section 104b and a part of the connection piece fastened to it are simultaneously mounted on the second bearing. As is known, the viscostatic coupling is generally configured for coaxial frontal coupling with a rotating cover or shaft, for example by means of a flanged or threaded joint. The present invention is likewise applicable to other types of coaxial coupling which can be frontally connected, axially downstream of the connection piece, so as to provide variable rotational coupling together of rotating connection piece / rotor and fan.

[0039] 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.

Claims

CLAIMS1. Support group (100) for supporting a cooling fan (101) for the engine of a vehicle, comprising a coupling (102) for coupling with the fan (101), a rotor (104) designed to rotate about a longitudinal axis (AV) so as to rotationally drive the coupling, and a support (106); wherein the support comprises a base (106) designed to be rigidly fastened to a fixed part of the engine and an axial extension (106a) extending cantilevered from the base to an end proximal to the coupling (102) for coupling with the fan (101); and wherein the group comprises:- a first bearing (105a) keyed onto the axial extension (106a) of the support, in a position proximal to the base (106) and distal, in use, from the coupling (102);- a second bearing (105b) keyed onto the axial extension (106a) of the support in a position proximal to the coupling; and wherein the rotor (104) is coaxially mounted on the axial extension of the support and comprises a first section (104a), axially distal from the coupling (102) and keyed onto the outer ring of the first bearing (105a), and a second section (104b) which extends axially and has a terminal end part, distal from the base, that is rigidly connected to a connection piece (107) which connects the rotor (104) to the coupling (102), said connection piece (107) being arranged in an axial position situated between the terminal end part of the rotor and the coupling (102); wherein the terminal end part of the rotor distal from the base and / or the connection piece (107) is / are mounted on the second bearing (105b) and wherein the coupling performs variable rotational coupling between said terminal end part and the fan.

2. Support group according to Claim 1 , wherein the first section (104a) of the rotor (104) comprises a movement take-up element for taking up the rotational movement, designed to be connected to movement generating means driven by a drive shaft.

3. Support group according to Claim 2, wherein said movement take-up element is in the form of a pulley.

4. Support group according to one of the preceding claims, wherein the connection piece (107) rigidly connected to the end part (104b1) of the second section (104b) of the rotor is in the form of a coaxial cover fastened to the end part of the second rotor section (104b) by fastening means.

5. Support group according to one of the preceding claims, wherein the first rotor section (104a) has a cross-sectional shape formed with a radially outer axial arm (104a1) shaped according to said movement take-up element, and a radial arm (104a3) extending from the outer axial arm towards the longitudinal axis of rotation (AV) and having a radially inner end connected to the second section (104b) of the rotor.

6. Support group according to the preceding claim, wherein the first rotor section (104a) also has a radially inner axial arm (104a2) keyed onto an outer race of the first bearing (105a) and wherein the radial arm connects the two axial arms of the first section.

7. Support group according to one of the preceding claims, wherein the second section (104b) has a cross-sectional shape formed with said terminal end part which comprises an axial end arm (104b1) proximal to the coupling (102) and with an axial arm (104b2) distal from the coupling (102) and connected to the first rotor section (104a), in particular to said radially inner end of the radial arm (104a3) of the first section (104a).

8. Support group according to the preceding claim, wherein the distal axial arm (104b2) of the second section (104b) of the rotor (104) is arranged radially internally with respect to the axial end arm (104b1) proximal to the coupling, and a radial arm (104b3) extending from the end arm (104b1) towards the axis of rotation connects the two axial arms (104b1,104b2).

9. Support group according to Claim 7 or 8, wherein the second bearing (105b) is arranged in an axial position such that the axial end arm (104b1) proximal to the coupling is keyed onto the outer race of the second bearing (105b).

10. Support group according to one of the preceding claims, wherein the coupling is a viscostatic coupling.

11. Support group according to one of the preceding claims, wherein the coupling is coaxially coupled frontally to the connection piece (107).

12. Assembly comprising a drive shaft rotating about a driving axis (AM) and a support group according to one of the preceding claims, wherein the drive shaft is coaxially coupled to a damper (112) arranged downstream of the drive shaft along the driving axis, wherein the longitudinal axis of rotation of the rotor is parallel and axially offset with respect to the drive shaft and wherein the damper (112) is arranged in an axial position situated between the first and second bearings of the support group.

13. Assembly according to the preceding claim, wherein an element for generating the movement for the rotor, in particular a pulley, is rotationally driven by the drive shaft and is connected via transmission means to a movement take-up element of the rotor (104) of the support group.

14. Assembly according to the preceding claim, wherein said movement generating element is arranged axially upstream of the damper (112).

Images