WO2010109309A1

WO2010109309A1 - Device for making electric windings

Info

Publication number: WO2010109309A1
Application number: PCT/IB2010/000664
Authority: WO
Inventors: Stefano Giachi
Original assignee: G.S. Engineering Di Stefano Giachi
Priority date: 2009-03-26
Filing date: 2010-03-24
Publication date: 2010-09-30
Also published as: ITFI20090061A1

Abstract

A device for making electric windings, comprising: a movable body (2) having a guide portion (3) for guiding at least a wire of conductive material (4) and placing said wire (4) around a support holding a plurality of turns; driving means (7) for driving said body (2) into a combined motion of translation and rotation; the driving means (7) comprise a motorized shaft (8) coupled to a first cam member (9) and to a second crank member (10); the first cam member (9) being engaged to a rotary unit (17) for the rotation of the movable body (2), and the second crank member (10) being engaged to a translatory unit (25) for translating the movable body (2).

Description

"DEVICE FOR MAKING ELECTRIC WINDINGS" Technical field of the invention

The object of the present invention is a device for making electric windings, in particular for forming windings onto stators or rotors of electric motors.

As it is known, electric windings are made by forming a series of turns onto a respective support such as a ferromagnetic core, for example.

In greater detail, the device for making electric windings are provided with a kinematic chain able to convey a wire of conductive material, for example copper, along a predetermined path and in a repeated manner to form a succession of turns.

One end of the wire is at first anchored to said support and, thereafter, it is wound several times around the support by a guided drive of the kinematic chain.

Background art

The known devices have a hollow shaft thereinside for housing at least a conductive wire. Developing at one end of the shaft is a bored beak, generally designated with the term "needle", to allow the wire to exit therefrom.

The hollow shaft is driven by the kinematic chain into a combined motion of translation and rotation to cause a first reciprocating motion thereof along its longitudinal axis, and a second rotational motion about the said longitudinal axis.

In this way, the needle is moved in a first straight direction, rotated in a first direction of rotation through a preset angle, moved in a second straight direction opposite to the first, and finally rotated in a second direction of rotation opposite to the first. Such succession is repeated so as to wind the wire many times around the said support. The hollow shaft may also be provided with two needles, opposite to each other, so as to form windings at the same time over two different supports.

The kinematic chain for driving the shaft is generally made up of an electric motor connected, via suitable transmission belts or toothed wheels, to a sleeve coaxially fitted to the hollow shaft. In this way, according to the rotation of the driving shaft, the transmission members provide for rotating the hollow shaft through the preset angle about its longitudinal axis. The driving shaft is also connected to a translatory unit, generally consisting of a cam mechanism, to transform the rotary motion of the driving shaft into a straight translation.

The cam mechanism is directly connected to an annular support which is coaxially associated externally to the shaft and is able to transmit the translatory motion to the same hollow shaft.

The known devices above described exhibit however major drawbacks . A first major drawback is due to the excessive weight and dimensions of the kinematic chain roughly described above.

Such kinematic chain, which results also constructionally complex owing to the particular combined motion to be impressed to the hollow shaft, comprises a series of mechanical components having large dimensions, being particularly heavy and, therefore, exhibiting a considerable inertia.

Consequently, the energy consumption for the operation of same kinematic chain is considerable, and the production costs and times are very high.

A further drawback of the above described devices stems from the large quantity of oil necessary to ensure an optimal lubrication and a suitable cooling of the kinematic components of same device. Yet another major drawback of the above described devices is given by the poor adaptability of the kinematic chain to various constructional requirements. It should be noted, in fact, that the stroke of the hollow shaft, as well as the rotation thereof, cannot be modified according to the sizes of the wire, of the support, or of the particular winding to be obtained. Disclosure of the invention

In this context, the technical task on which the present invention is based, is to propose a device for making electric windings able to overcome the above cited drawbacks of the prior art.

In particular, the object of the present invention is to provide a device for making electric windings able to limit the overall dimensions and weight of the wire-driving mechanical members.

A further object of the present invention is to provide a versatile device for making electric windings able to modify the combined motion of the needle carrying the electric wire. The indicated technical task and the specified objects are substantially achieved by a device for making electric windings comprising the technical characteristics disclosed in one or more of the appended claims. Further characteristics and advantages of the present invention will appear more clearly by the indicative, and thus non-limitative, description of a preferred, but nonexclusive, embodiment of a device for making electric windings, as illustrated in the accompanying drawings, wherein: - Fig. 1 is a partially sectioned plan view from above of a device for making electric windings according to the present invention;

- Figs. 2a-2c are partially sectioned side elevation views of the device of Fig. 1 taken on line II-II, with some parts removed for a better illustration of others, showing three different operating positions;

- Figs. 3a and 3b are partially sectioned side elevation views of the device of Fig. 1 taken on line III-III, with some parts removed for a better illustration of others, showing two different operating positions; and

- Figs. 4a and 4b are schematic side elevation views of a constructional detail of the device according to the present invention.

With reference to the attached drawings, numeral 1 indicates as a whole a device for making electric windings. In particular, present invention is adapt to make windings of rotors and stators of respective electric motors As shown in Fig. 1, the device 1 comprises a movable body 2 having a guide portion 3 for guiding at least one wire of conductive material 4, for example copper, and being able to receive the wire 4 around a support.

In particular, present invention is adapt to make windings of rotors and stators of respective electric motors It will be noted that the support is not shown in the attached figures since it is of known type and does not make part of the present invention. Such support may consist, for example, of a ferromagnetic core of a respective spool onto which the electric winding is to be formed. Preferably, the movable body 2 comprises a tubular hollow element 5, preferably a hollow shaft, extending along a respective longitudinal axis X.

Advantageously, the hollow shaft 5 receives therein two wires of conductive material 4, each of which extends along the longitudinal development of same shaft 5.

It should be noted, that the guide portion 3 exhibits two protruding sections 3a, 3b, extending perpendicularly from one end 5a of the hollow shaft 5 and each having a hole for the exit of a respective wire 4. The movable body 2 is partially received within a box- shaped frame 6 provided with an aperture for the hollow shaft 5 to go through. In this situation it can be noted that the end 5a of shaft 5 results outside the box-shaped frame 6. Developing from the opposite side of end 5a is a tail portion 5b of the hollow shaft 5, also exiting from the frame 6 and apt to the insertion of the two wires of conductive material 4.

Housed within the frame 6 are drive means 7 able to drive the body 2 into a combined motion of translation 100 along the axis X and of rotation 101 about the axis X.

In particular, the driving means 7 comprise a motorized shaft 8 driven by a suitable motor which can rotate the shaft 8 about a respective longitudinal axis Y. The motor may consist, for example, of an electric motor, the latter being not shown as being of known type and making no part of the present invention.

Again with reference to Fig. 1, it can be noted that the motorized shaft 8 exhibits a first end 8a able to be coupled to said motor, and a middle region 8c on which a first cam member 9 is keyed.

Developing from opposite side of the first end 8a of shaft 8 is a second end 8b engaged to a second crank member 10. In this situation, it can be noted that the first cam member 9 results disposed between the first and second ends 8a, 8b of the motorized shaft 8.

By referring in particular to Figs. 3a and 3b, it can be seen that the first cam member 9 is made up of a cam 11 rotating about the longitudinal axis Y of the motorized shaft 8. The cam 11 is keyed to the motorized shaft 8 to rotate therewith and is received within a sliding arched space 13 defined by a respective cam-follower element 12. Advantageously, two roller bearings are mounted on the inner surface of the arched space 13 for the engagement of cam 11. More in particular, the cam-follower element 12 has a substantially C-shaped portion 12a which defines internally the said arched space 13 for the cam 11 to slide therein. Developing from the opposite side of the arched space 13 is a coupling portion 14, provided with a sliding skid 15.

The cam-follower element 12 is also fitted to a vertical guide 16 to allow a reciprocating straight translation of same element 12. In this way, owing to the rotation of cam 11, the cam- follower element 12 is driven into a reciprocating motion, that is, a periodic alternate rectilinear motion along a respective direction D perpendicular to the longitudinal axis Y of the shaft. Consequently, as illustrated in Figs. 3a and 3b, the cam- follower element 12 translates between a lifted position (Fig. 3a) and a lowered position (Fig. 3b) .

The first cam member 9 is also engaged to a unit 17 for the rotation of the movable body 2 able to rotate the hollow shaft 5 about the respective longitudinal axis in two directions opposite to each other.

As illustrated in Fig. 1, the rotary unit 17 comprises a rod 18 pivoted in correspondence of a respective median region 18c to rotate about an axis Z parallel to the axis of rotation X of hollow shaft 5. By referring in particular to Figs. 4a and 4b in which the rod 18 is illustrated in detail, it can be seen that the rod 18 exhibits a first end 18a provided with an arched surface 19 having a toothing 20, and a second end 18d opposite to the first end 18a. The coupling portion 14 of the cam-follower 12 and, in particular, the sliding skid 15, is housed in a seat 21 formed on the second end 18d of rod 18. In particular, the seat 21 is shaped as a slotted hole to allow the skid 15 to axially slide during the motion of the cam-follower 12. Consequently, owing to the motion of the cam-follower 12 along the said direction D, an oscillatory motion is imposed to the rod 18 along the arched direction indicated by A in Figs. 4a and 4b.

The toothing 20 of the arched surface 19 is made to mesh all the time with a toothed crown 22, externally fitted to said hollow shaft 5, so as to be rotated by the oscillation of rod 18 along the direction A.

Advantageously, the motion of rod 18, transmitted via the surface 19 and toothed crown 22, is cause for the rotation of the hollow shaft 5 about the axis of rotation X in one of the directions indicated with numeral 101 in Fig. 1. It should be noted that the excursion of skid 15 within the seat 21 determines the oscillation of the hollow shaft 5. Consequently, by changing the position of skid 15 within the seat 21 it is possible to adjust the amplitude of oscillation of rod 18 and, therefore, also the angle of rotation of the toothed crown 22 and hollow shaft 5. By referring in particular to Figs. 1 and 2a to 2c, it can be seen that the motorized shaft 8 comprise a dovetail portion 23 having its longitudinal axis of development perpendicular to the longitudinal axis Y of the same motorized shaft 8.

Developing from opposite sides of portion 23 are respective ends 23a, one of which is provided with a sliding shoe 24. As a result, the shaft 8 rotates about the said axis Y to move the sliding shoe 24 along a respective circular path. The second cam member 10 is engaged to a unit 25 for the translation of the hollow shaft 5 and is able to move the same shaft 5 along the said axis X in the direction indicated by numeral 100 in Fig. 1.

In particular, the translatory unit 25 comprises a guide element 26, preferably made up of a sliding link, provided with a receiving slot 27 having substantially a straight development and able to hold therein the shoe 24 of motorized shaft 8. As can be seen in the sequence shown in Figs. 2a, 2b and 2c, during the rotation of the motorized shaft 8, the shoe 24 slides within the slot 27 so as to drive the guide element 26 into a reciprocating motion with variable velocity.

In other words, by following the path of shoe 24 along its circular path, the guide element 26 is moved alternately toward the end 5a (Fig. 2b) and then toward the tail portion 5b of hollow shaft 5. Advantageously, the guide element 26 is rigidly associated with the movable body 2 to translate the latter along the straight direction 100 in a reciprocating motion and at variable speed. Consequently, during the rotation of motorized shaft 8, the hollow shaft 5 is rotated and contemporarily translated by driving into motion said guide element 26.

Advantageously, the shoe 24 is mounted on an adjustable saddle 24a, so as to change the position of shoe 24 onto the support 23. In other words, the saddle 24a allows varying the distance between the shoe 24 and the central region of portion 23 corresponding to the axis of rotation Y of motorized shaft 8. In this way, it is possible to change the circular path 24 during the rotation of portion 23 with a consequent change in displacement of guide 26 and of hollow shaft 5 connected thereto.

Advantageously, by displacing the shoe 24 it is possible to either increase or decrease the stroke of hollow shaft 5 along the respective direction of translation 100.

Preferably, the hollow shaft 5 is provided with at least one slotted guide 28, interposed between the toothed crown 22 and the external surface of hollow shaft 5. Such slotted guide 28 allows the hollow shaft 5 to translate along the straight direction 100 with respect to the crown 22 and, at the same time, to transmit the rotational motion imposed by the crown 22.

The slotted guide 28 is preferably made up of a series of radial projections 28a extending from the external surface of hollow shaft 5 and having a development corresponding to the longitudinal development of same shaft 5. The radial projections 28a slide within suitable cavities 28b formed in an internal annular region of crown 22, as best visible in the section view of Fig. 1. Provision may also be made for a hydraulic lubrication system (not described nor shown as of known type) able to facilitate the sliding of mechanical moving parts. In particular, such lubrication system may include a basin for collecting and recirculating the lubrication liquid by means of a pump, for example.

Advantageously, a device according to the present invention may also comprise a heat exchanger to cool all the mechanical moving parts by means of the lubricating oil. It is to be pointed out that, in use, the motorized shaft 8 imposes the combined motion of the movable body 2 by means of two members 9, 10.

In fact, the first cam member 9 provides for the oscillation of the hollow shaft 5 about its axis X; at the same time, the second crank member 10 drives the hollows shaft 5 into a traslation motion along axis X.

Consequently, the hollow shaft 5 moves the two protruding portions 3a into a straight motion up to a limit position away from the frame 6. Thereafter, the hollow shaft 5 is rotated to change the angular position of the protruding portions 3a. At this point, the protruding portions are again translated close to frame 6 to be rotated again in a direction opposite to the previous one. The rotation in the two directions, indicated by numeral 101 in Fig. 1, is due to the oscillation in the direction A of rod 18, whereas the motion close to/away from the frame 6 is determined by the reciprocating motion of guide 26.

Advantageously, as can be noted, the whole device exhibits particularly contained dimensions. Such advantage is due to the construction of cam member 9 and crank member 10 as well as of rotary and translatory units connected thereto. The kinematic chain for driving the hollow shaft 5 results in fact of limited dimensions and weight. As a consequence, there is obtained also a considerable saving of energy consumption and production cost. A further major advantage is due to the particular versatility of driving means 7, which allow them to change the stroke (motion 100) and the angle (motion 101) of the hollow shaft 5 according to the size of wire 4 and the type of support onto which the windings are to be formed. Actually, as above described, by adjusting the position of the skid 15 within the seat 21 it is possible to change the excursion of rod 18 and, therefore, also the rotation of crown 22. In this way, the rotation of hollow shaft 5 is adjusted. Moreover, by adjusting the position of shoe 24 within the slot 27 it is possible to change the excursion of guide 26 and, therefore, also the stroke of hollow shaft along the direction 100.

Claims

1. Device for making electric windings, comprising:

- a movable body (2) having a guide portion (3) for guiding at least a wire of conductive material (4) and placing said wire (4) around a support holding a plurality of turns;

- means (7) for driving said body (2) into a combined motion of translation and rotation; characterized in that said driving means (7) comprise a motorized shaft (8) coupled to a first cam member (9) and to a second crank member (10); said first cam member (9) being engaged to a unit (17) for the rotation of the movable body (2), and said second crank member (10) being engaged to a unit (25) for the translation of the movable body (2) .

2. Device according to the preceding claim, characterized in that said motorized shaft (8) comprises a first end (8a) apt to be coupled to a respective motor for rotating the same shaft (8) about a respective longitudinal axis (Y), and a second end (8b) opposite to the first (8a) and engaged to said second crank member (10); said first cam member (9) being associated with a portion (8c) of the motorized shaft (8) intermediate between said first and second ends (8a, 8b).

3. Device according to claim 1 or 2, characterized in that said first cam member (9) comprises: a cam (11) rotating about said longitudinal axis (Y) of the motorized shaft (8); and a cam-follower element (12) coupled to said cam (11) and movable with a reciprocating motion in a respective direction (D) perpendicular to the longitudinal axis (Y) of shaft (8) .

4. Device according to the preceding claim, characterized in that said cam-follower element (12) comprises: a portion (12a) substantially C-shaped and defining an arched space (13) for the sliding of said cam (11); and a coupling portion (14), extending opposite to said arched space (13), and associated with said rotary unit (17).

5. Device according to the preceding claim, characterized in that said rotary unit (17) comprises a rod (18) pivoted in correspondence of a respective median region to pivot about an axis (Z) parallel to the axis of rotation (X) of the movable body (2); said rod (18) exhibiting a first end

(18a) provided with an arched surface (19) having a toothing (20), and a second end (18d) opposite to the first

(18a); said coupling portion (14) of the cam-follower element (12) being received in a seat (21) formed on the second end (18b) of said rod (18) to drive the same rod

(18) into an oscillatory motion during the reciprocating motion of the cam-follower element (12).

6. Device according to any of the preceding claims, characterized in that said motorized shaft (8) comprises a portion (23) having axis of longitudinal development perpendicular to the longitudinal axis (Y) of shaft (8); said portion (23) exhibiting, at a respective end (23a) , a sliding shoe (24) movable along a circular path during the rotation of shaft (8) .

7. Device according to the preceding claim, characterized in that said translatory unit (25) comprises a guide element (26) having a housing slot (27) of substantially straight shape; said shoe (24) being slidable within said slot (27) as it is driven along the circular path to drive the guide element (26) into a reciprocating motion.

8. Device according to the preceding claim, characterized in that said guide element (26) is rigidly associated with said movable body (2) for the translation thereof in a straight direction (100) with a reciprocating motion and at a variable speed.

9. Device according to any of the preceding claims, characterized in that said movable body (2) comprises a hollow shaft (5) extending along a respective longitudinal axis (X) corresponding to said straight direction of movement (100); said wire (4) being housed within the hollow shaft (5) and projecting out of one end (5a) of same hollow shaft (5) .

10. Device according to the preceding claim, when dependent on claim 5, characterized in that said movable body (2) further comprises a toothed crown (22) externally keyed to said hollow shaft (5) and meshing with the toothing (20) of the first end (18a) of said rod (18); said rod (18), during its oscillatory motion, rotating the toothed crown (20) and the hollow shaft (5) about said axis of rotation (X) .

11. Device according to the preceding claim, characterized in that it further comprises at least a slotted guide (28) interposed between said toothed crown (22) and hollow shaft (5) to allow the hollow shaft (5) to translate in straight direction (100) with respect to said crown (22) and to transmit the rotation from the crown (22) to said hollow shaft (5) .