Title of Invention

"ROTOR AND METHOD OF MANUFACTURING THEREOF"

Abstract Rotor, comprising a transmission element (39), a vane carrier (37, 137) and at least one vane, said transmission element (39, 139, 239) transmitting a torque to said vane carrier (37, 137, 237), wherein the vane carrier (37, 137, 237) comprises interposed elements (1, 101, 201) immovable radially with respect to the vane carrier and arranged in the region of bearing surfaces between the transmission element and the vane carrier in order to transmit the bearing force of the transmission element of the vane carrier, and in that said interposed elements (1, 101, 201) are resistant to wear caused by the friction of the transmission element, characterized in that said interposed element secures the transmission element secures the transmission element to the vane carrier.
Full Text present invention relates to rotor and method of manufacturing thereof.
The present invention relates mainly to a rotor with reduced wear and to a pump comprising such a rotor, such. a pump being used particularly in the motor vehicle industry as an air vacuum source for brake boosting devices. The present invention also relates to combined pumps used, for example, both as a vacuum source and in order to feed fuel to a thermal engine.
Pumps of a known type, in particular used as an air vacuum source, are vane pumps comprising at least one vane and a rotor connected to a drive device, for example a shaft driven in rotation, for example a camshaft. The rotor comprises a vane carrier, at least one vane and an element for the transmission of a drive torque to the camshaft. The vane carrier" comprises a cavity located at a first axial end oriented toward the drive shaft and at"a second end opposite the first end, at least one slot extending axially and partially from the second end toward the first end, the vane being mounted movably in translational motion in said slot.
At least one pump of the type described above is arranged at one end of the camshaft, and the rotor is driven in rotation by means of the transmission element driven by the shaft, thus ensuring the extraction of the air and the generation of a vacuum.
In a known way, the rotor is produced from steel. However, in order to reduce its weight and its cost, the vane carrier is produced from plastic, although the transmission element is still produced from steel since it directly receives the torque from the drive device. Problems of reliability may then arise, to be precise the contact between the transmission element and the vane carrier may cause the wear of the vane carrier.

In actual fact, in a known way, the axis of the vacuum pump and the axis of the drive means, for example an electric motor, are not perfectly coaxial, and, consequently, the transmission element arranged at the end of the drive shaft and transmitting the rotational movement to the vane carrier likewise has a radial displacement with respect to the body of the vane carrier, this displacement being liable to cause wear as a result of the friction of the vane carrier.
There is no possibility of envisaging the use of special materials resistant to frictional wear in order to produce the vane carrier and affording the same advantages as plastic, since the latter have a high cost price.
Consequently, one object of the present invention is to provide a pump having a long useful life.
An object of the present invention is also to provide a reliable pump.
An object of the present invention is also to offer a lightweight pump.
An object of the present invention is also to offer a pump having low cost.
It has always been thought that, to avoid damage to the rotor caused by the friction of the transmission element, the rotor had to be produced from materials with much greater resistance to wear or the connection between the transmission element and the rotor had to be modified accordingly, which, in both cases, presents problems of high cost. The Applicant, then, realized that, without the pump of the known type having to be modified, the addition of a part of simple manufacture in the pump in the region of the transmission element/vane carrier connection, said part being fixed
with respect to the vane carrier, appreciably reduced the wear of the' rotor.
These objects are achieved by means of a pump comprising a rotor comprising an element for the transmission of a torque received by a drive shaft, a vane carrier driven by the transmission element, and at least one vane, said vane carrier likewise comprising an element interposed between the transmission element and the body of the vane carrier, the interposed element being radially immovable with respect to the vane carrier.
In other words, the first element drives a second element in rotation, the second element comprising an insert means immovable radially with respect to the second element in contact with the first transmission element and resistant to the frictional wear caused by the radial displacement of the first element.
The subject of the present invention is, mainly, a rotor comprising a transmission element, a vane carrier and at least one vane, said transmission element transmitting a torque to said vane carrier, characterized in that the vane carrier comprises interposed elements immovable radially with respect to the vane carrier and arranged in the region of bearing surfaces between the transmission element and'the vane carrier in order to transmit the bearing force of the transmission element to the vane carrier, and in that said interposed elements are resistant to the wear caused by the friction of the transmission element.
The- subject of the present invention is also a rotor, characterized in that the interposed elements comprise two parallel wings.
The subject of the present invention is also a rotor, characterized in that the two wings are connected by means of a plate.
The subject of the present invention is also a rotor, characterized in that the wings extend perpendicularly to the plate and on the same side of the plate.
The subject of the present invention is also a rotor, characterized in that the wings are symmetrical with respect to a longitudinal axis of the plate.
The subject of the present invention is also a rotor, characterized in that the interposed elements are secured to a central rod carried by the vane carrier.
The subject of the present invention is also a rotor, characterized in that the plate comprises an orifice, into which issue at least two tabs cooperating with the central rod carried by the vane carrier.
The subject of the present invention is also a rotor, characterized in that the plate comprises fastening means cooperating with second fastening means carried by the vane carrier.
The subject of the present invention is also a rotor, characterized in that the fastening means carried by the plate comprise an orifice of smaller diameter edged with a sleeve, and in that the fastening means comprise a rod of larger diameter carried by the vane carrier, said rod being equipped with an annular bead which projects on the periphery and is formed after the force mounting of the plate around the rod, and in that the sleeve is arranged between the bead and the transmission element after mounting.
The subject of the present invention is also a rotor, characterized in that the plate comes to bear on a
bearing surface formed in the periphery of said rod perpendicularly to the axis of the rod.
The subject of the present invention is also a rotor, characterized in that the transmission element is made from metallic material and the vane carrier is made from plastic.
The subject of the present invention is also a rotor, characterized in that the transmission element is produced from steel.
The subject of the present invention is also a rotor, characterized in that the interposed element is produced from metallic material.
The subject of the present invention is also a rotor, characterized in that the interposed element is produced from spring steel.
The subject of the present invention is also a rotor, characterized in that the interposed element is produced by bending.
The subject of the present invention is also a rotor, characterized in that the fastening means carried by the plate of the interposed element are produced by stamping.
The subject of the present invention is also a rotor, characterized in that the interposed elements are incorporated into the plastic vane carrier during the manufacture of the vane carrier by molding, the interposed elements being formed by wings arranged in the region of the bearing surfaces between the transmission element and the body of the vane carrier.
The subject of the present invention is also a pump forming at least one vacuum source, characterized in
that it comprises at least one rotor according to the present invention.
The subject of the present invention is also a pump, characterized in that the element is driven by a camshaft.
The subject of the present invention is also a pump, characterized in that the element is driven by an electric motor.
The subject of the present invention is also a pump, characterized in that the element is driven by a pulley driven by a belt.
The subject of the present invention is also a method for manufacturing of a rotor according to the present invention, comprising the step of manufacturing the vane carrier by plastic molding, characterized in that it comprises, furthermore, the step of
arranging the wings, before the injection of the plastic into the mold for manufacturing the vane carrier, . in such a way that said wings are arranged in the region of the bearing surfaces between an element for the transmission of a rotation torque and the vane carrier, and in such a way that they are made immovable from the body of the vane carrier during the removal of the vane carrier from the mold.
The present invention will be understood more clearly from the following description and from the accompanying Figures in which:
Figure 1 is a three-quarter view of a pump according to the present invention,
Figure 2 is a three-quarter view of a first embodiment of a bearing element according to the present invention,
Figure 3 is an isometric perspective view of a rotor comprising the element of Figure 2,
Figure 4 is a top view of Figure 3 without the bearing element,
Figure 5 is a three-quarter view of a second embodiment of a rotor according to the present invention,
Figure 6 is a sectional view of a bearing element/transmission element assembly according to the present invention,
Figure 7 is a view of a detail of Figure 6,
Figure 8 is a three-quarter view of a third embodiment of a rotor according to the present invention.
An interposed element 1 comprising at least two wings 3, 5, advantageously in one piece and connected by means of a plate 7, can be seen in Figures 1 and 2. The plate 7 is substantially plane in terms of a first longitudinal dimension 1 and a second transverse dimension L, which are much greater than a third dimension e, and has a longitudinal axis XX', the plate 7 comprising two longitudinally opposed branches 9, 11. The wings 3, 5 extend from the branches 9, 11 in the direction of the arrow F perpendicularly to the plane of the plate, said wings being opposite to one another with respect to the axis XX' .
The plate 7 likewise comprises means 13 for fastening the part 1 to a rotor. The fastening means comprise at least two tabs 15, 17 issuing into an orifice 21 formed at the center of the plate 7. The tabs 15, 17 are
delimited by four slots 23 formed in the plate 7 and extending radially from the orifice 21 in the direction of the outer periphery of the plate 3 and advantageously parallel to one another. Advantageously, the slots form a non-zero angle with the longitudinal axis XX' of the plate 3.
The part 1 is fastened, blocked, to the rotor by being force-fitted onto a rotor part cooperating with .the orifice 21 by means of the tabs 15, 17 which are elastic in a transverse direction to the plane of the plate 7.
The part 1 is advantageously produced from a metallic material, for example from spring steel.
The part 1 is advantageously produced by bending.
A vane pump 33 according to the present invention can be seen in Figure 1, said pump comprising a rotor 35
(Figures 3 and 4) mounted in a pump body and driven, for example, by a camshaft of a motor vehicle engine
(not illustrated). The rotor comprises a vane carrier 37, an element 39 for the transmission of the torque of the vehicle engine to the vane carrier, a vane (not illustrated) and a bearing part 1. The vane carrier 37 comprises a body 37' advantageously produced from plastic and equipped at a first longitudinal end with a first portion 36 of smaller outside diameter and with an axis YY' , formed by a blind sleeve 41, and, at a second end opposite the first end, with a cylindrical second portion 38 of larger outside diameter, coaxial to the first portion 36 and connected to the first portion 36 of smaller outside diameter by means of a shoulder 40. The sleeve 41 has an internal shape with a cruciform cross section, advantageously with four branches. The branches of the cross are separated, advantageously by means of spherical segments 43, and the inner surface of the branches comprise faces 61
extending radially and parallel to the axis YY' . The cylindrical portion 38 of larger outside diameter is equipped with a slot 42 capable of receiving a vane, the slot 42 extending axially along YY' from a first longitudinal end to a second longitudinal end formed partially by the shoulder 40, and passing radially through the sleeve 41.
The body 37' of the vane carrier 37 likewise comprises a rod extending from the bottom of the sleeve 41 toward the open end of the sleeve and parallel to the axis YY1 .
The transmission element 39 comprises a base 50 of axis YY' with four branches 51, 53, 55, 57 arranged in the form of a cross and connected by means of portions of an arc of a circle 47, and an advantageously oblong central orifice 49 allowing the passage of the rod 45. The transmission element 39 likewise comprises, on one face of the base 50, radially opposite dogs 56 which project and which extend axially from the branches 51, 53 along the axis YY' .
The branches 55, 57 of the transmission element 39 comprise faces 59, 60 respectively extending in a radial direction and in a direction parallel to the axis YY' and opposite to one another with respect to the axis YY'.
The transmission element 39 is arranged in the inner recess of the sleeve 41 of the body 37' of the vane carrier, the portions of an arc of a circle 47 opposite the spherical segments 43, the rod 45 penetrating into the orifice 49, the face comprising the dogs 56 being oriented toward the outside, and the faces 59, 60 each cooperating respectively with a face 61 of the inner surface of the sleeve.
The transmission element is advantageously produced from metallic material, for example from steel.
The vane carrier 37 comprises an interposed element 1 according to the present invention, in such a way that the wings 3, 5 of the element 1 are inserted between the transmission element 39 and the body 37' of the vane carrier 37 between the surfaces 59, 60 and the faces 61 and transmit the bearing force of the transmission element 39 to the vane carrier 37. The element 1 is mounted on the vane carrier 37 in such a way that there is no radial movement of the wings with respect to the vane carrier 37, thus preventing wear caused by the friction of the vane carrier. According to the first embodiment, the element 1 is secured to the body 37' of the vane carrier by the snapping of the plate 7 connecting the wings 3, 5 in the direction of the arrow onto the free end of the rod by means of the tabs 15, 17.
The element 1 is resistant to frictional wear during the displacement of the transmission element with respect to the vane carrier, and the body of the vane carrier then does not experience the wear caused before by the friction of the transmission element 39 on the body 37' of the vane carrier 37, without the transmission of the to.rque being modified. Consequently, a pump having a prolonged useful life is obtained.
Moreover, the element 1 advantageously makes it possible to secure the transmission element 39 to the vane carrier 37, thus preventing the separation of the transmission element 39 from the vane carrier 37 during manipulations of the pump comprising such a device.
A second embodiment of an element 101 according to the present invention can be seen in Figure 5, this differing from the element 1 according to the first
embodiment in the means for securing the element to the vane carrier.
We shall therefore describe in detail only the securing means.
The element 101 comprises first means 113a for securing the element 101 to the body 137' of the vane carrier without radial movement, said first securing means cooperating with second means 113b for securing the element to the body of the vane carrier, said second securing means being carried by the body of the vane carrier. The first means 113b comprise an orifice 121 arranged substantially at the center of the plate 107 and a sleeve 123 edging the orifice 121 and extending perpendicularly to the surface of the plate 107 in the opposite direction to that in which the wings 103, 105 extend.
In Figure 6 and in Figure 7, which ••• illustrates an enlarged detail, designated by A, of Figure 6, can be seen the rotor of axis YY' according to the second embodiment, comprising the second means 113b. The second means 113b are formed by a . central rod 145 carried by the body of the vane carrier 137 of an outside diameter D greater than the diameter of the orifice 121 formed in the plate 107 of the element 101.
The rod 145 advantageously comprises a bearing surface 150 for the bearing element 101, the surface 150 being formed by an annular offset formed on the periphery of the rod 145 substantially perpendicularly to the axis YY' , in such a way that, when the transmission element 139 and the bearing element are arranged in the vane carrier, a part of the plate 107 which surrounds the orifice 121 rests on the offset 150.
The element 101 is then secured to the vane carrier, after the installation of the transmission element 139,
by the sleeve 123 being force-fitted around the rod 145. During assembly, owing to the difference in diameter between that d of the orifice 121 and that D of the rod 145, there is a temporary elastic reduction in the diameter D of the rod 145. Then, when the plate 107 comes to bear against the annular bearing surface 150, the rod 145 expands elastically, at the same forming an annular bead 146, in such a way that the sleeve 123 is arranged between the transmission element 139 and the bead 146 after mounting.
Moreover, the first securing means 113a, more specifically the sleeve 123, is advantageously produced by stamping, thus giving the connection 148 between the plate 7 and the sleeve 123 a substantially rounded shape, which, when the pump is in operation, has the advantage of reducing the risks of wear of the central rod 145 and also of avoiding the formation of chips during the mounting of the element 101 on the vane carrier.
Furthermore, the means 101 advantageously makes it possible to secure the transmission element 139 to the vane carrier 137, thus preventing the separation of the transmission element 139 from the vane carrier 137 during manipulations . of the pump comprising such a device.
In Figure 8 can be seen a third embodiment of an element 201 according to the present invention, which is fixed with respect to the vane carrier, is resistant to frictional wear attributable to the radial movement of the transmission element and is incorporated in the body of the vane carrier 337 made from plastic or the like during the molding operation. The interposed element 201 is formed by two independent wings 203, 205 having substantially the same shape as those of the first and second embodiments and arranged in the mold, before the injection of the plastic, said wings being
secured to the body of the vane carrier during the solidification of the plastic.
The wings 203, 205 are arranged in the mold in such a way that, after the mounting of the vane carrier 237/transmission element 239 assembly, they are interposed between the body of the vane carrier 237 and the transmission element 239 in the direction of rotation of the transmission element 239.
The interposed element according to the third embodiment is, for example, manufactured from metal, from plastic reinforced with glass fibers or from ceramic.
It goes without saying that the present invention is not limited to a rotor with a single vane, the rotor according to the present invention being capable of comprising a plurality of vanes by virtue of a simple modification of the present invention by a person skilled in the art.
It also goes without saying that the pump according to the .present invention may be driven by a camshaft with a thermal engine, but also by any device capable of supplying a rotational movement.
It likewise goes without saying that the pump according to the present invention forms at least one vacuum source, but is also capable of feeding liquid, for example fuel, to an engine.
The present invention applies particularly to the motor vehicle industry.
The present invention applies mainly to the brake industry and, more particularly, to brake boosting devices.











We Claim:
1. Rotor, comprising a transmission element (39), a vane carrier (37,137) and at least one vane, sakl transmission element (39, 139, 239) transmitting a torque to said vane carrier (37, 137, 237), wherein the vane carrier (37, 137, 237) comprises interposed elements (1,101, 201) immovable radially with respect to the vane carrier and arranged in the region of bearing surfaces between the transmission element and the vane carrier in order to transmit me bearing force of the transmission element of the vane carrier, and in mat said interposed elements (1,101, 201) are resistant to wear caused by the friction of the transmission element, characterized in that said interposed element secures the transmission element to the vane carrier..
2. Rotor as claimed in claim 1, wherein the interposed elements (1, 101, 201) comprise two parallel wings (3,5,103,105,203,205).
3. Rotor as claimed in claim 2, wherein the two wings (3,103, 5,105) are connected by means of a plate (7,107).
4. Rotor as claimed in claim 3, wherein the wings (3, 103, 5, 105) extend perpendicularly to the plate (7,107) and on the same side of the plate (7,107).
5. Rotor as claimed in claim 3 or 4, wherein the wings (3, 5, 103, 105) are symmetrical with respect to a longitudinal axis (XX') of the plate (7,107).
6. Rotor as claimed in any one of claims 3 to 5, wherein the interposed elements are secured to a central rod (45,145) carried by the vane carrier (27,137).
7. Rotor as claimed in the preceding claim, wherein the plate (7) comprises an orifice (21), into which issue at least two tabs (15, 17) cooperating with the central rod (45) carried by the vane carrier (37).
8. Rotor as claimed in claim 6, wherein the plate comprises fastening means (113a) cooperating with second fastening means (113b) carried by the vane carrier.
9. Rotor as claimed in claim 8, wherein the fastening means (113a) carried by the plate (107) comprise an orifice (121) of smaller diameter (d), edged with a sleeve (123), and in mat the fastening means (113b) comprise a rod (145) of larger diameter (D), carried by the vane carrier, said rod being equipped with an annular bead (146) which projects on the periphery and is formed after the force mounting of the plate (107) around the rod (145), and in that the sleeve is arranged between the bead (146) and the transmission element after mounting.
10. Rotor as claimed in the preceding claim, wherein the plate (107) comes to bear on a bearing surface (150) formed in the periphery of said rod (145) perpendicularly to the axis of the rod
11. Rotor as claimed in any one of the preceding claims, wherein the transmission element (39, 139, 239) is made from metallic material and the vane carrier (37, 137, 237) is made from plastic.
12. Rotor as claimed in the preceding claim, wherein the transmission element is produced from steel.
13. Rotor as claimed in any one of the preceding claims, wherein the interposed element (1,101,201) is produced from metallic material.
14. Rotor as claimed in the preceding claim, wherein the interposed element is produced from spring steel.
15. Rotor as claimed in claim 13 or 14, wherein the interposed element (1, 101) is produced by bending.
16. Rotor as claimed in either one of claims 9 or 10, wherein the fastening means (113a) carried by the plate of the interposed element (101) are produced by stamping.
17. Rotor as claimed in claim 11 in combination with claims 1 or 2, wherein the interposed elements (201) are incorporated in the plastic vane carrier during the manufacture of the vane carrier by molding, the interposed elements (201) being formed by wings (203, 205) arranged in the region of the bearing surfaces between the transmission element and the body of the vane carrier.

18. Pump, forming at least one vacuum source, wherein it comprises at least one rotor as claimed in one of the preceding claims.
19. Method for manufacturing a rotor as claimed in claim 1, comprising the step of manufacturing the vane carrier by plastic molding, wherein it comprises, furthermore, the step of
arranging the wings (203,205), before the injection of the plastic into the mod for manufacturing the vane carrier (237), in such a way that said wings are arranged in the region of the bearing surfaces between an element for the transmission of a torque and the vane carrier, and in such a way that they are made immovable from the body of the vane carrier during the removal of the vane carrier from the mold.


Documents:

2055-DELNP-2003-Abstract-(04-09-2009).pdf

2055-delnp-2003-abstract.pdf

2055-DELNP-2003-Claims (18-09-2009).pdf

2055-DELNP-2003-Claims-(04-09-2009).pdf

2055-DELNP-2003-Claims-(25-11-2009).pdf

2055-delnp-2003-claims.pdf

2055-DELNP-2003-Correspondence-Others-(04-09-2009).pdf

2055-DELNP-2003-Correspondence-Others-(07-09-2009).pdf

2055-DELNP-2003-Correspondence-Others-(14-09-2009).pdf

2055-DELNP-2003-Correspondence-Others-(18-09-2009).pdf

2055-DELNP-2003-Correspondence-Others-(25-11-2009).pdf

2055-delnp-2003-correspondence-others.pdf

2055-DELNP-2003-Description (Complete)-(04-09-2009).pdf

2055-delnp-2003-description (complete).pdf

2055-DELNP-2003-Drawings-(04-09-2009).pdf

2055-delnp-2003-drawings.pdf

2055-DELNP-2003-Form-1-(04-09-2009).pdf

2055-delnp-2003-form-1.pdf

2055-delnp-2003-form-18.pdf

2055-DELNP-2003-Form-2-(04-09-2009).pdf

2055-delnp-2003-form-2.pdf

2055-DELNP-2003-Form-3-(14-09-2009).pdf

2055-delnp-2003-form-3.pdf

2055-delnp-2003-form-5.pdf

2055-DELNP-2003-GPA-(04-09-2009).pdf

2055-delnp-2003-gpa.pdf

2055-DELNP-2003-Petition-137-(14-09-2009).pdf

2055-DELNP-2003-Petition-138-(14-09-2009).pdf

abstract.jpg


Patent Number 237505
Indian Patent Application Number 2055/DELNP/2003
PG Journal Number 01/2010
Publication Date 01-Jan-2010
Grant Date 23-Dec-2009
Date of Filing 02-Dec-2003
Name of Patentee VHIT S.P.A. VACUUM & HYDRAULIC PRODUCTS ITALY
Applicant Address VIA CAVALLI 53/A, I-26013 CREMA, ITALY
Inventors:
# Inventor's Name Inventor's Address
1 LEONARDO CADEDDU VIA STAZIONE 23, I-26013 CREMA, ITALY
2 EMILIO SAMANNI VIA SEVERGNINI 49/A, I-26010 IZANO, ITALY
3 ALBERTO ANASTASI VIA PASTRENGO 20, I-10128 TORINO, ITALY
4 ALESSANDRO FAUDA VIA MOLINETTO, CISLIANO, I-20080 MILAN, ITALY
PCT International Classification Number F04C 2/344
PCT International Application Number PCT/IB02/03448
PCT International Filing date 2002-05-29
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 2001A 000521 2001-06-01 Italy