Apparatus and method for twisting wires applied to an electric machine

Abstract

A device (20) for twisting wires (9) used in an electric motor (8), comprising: a device (1) having a housing (10); a fork (12) supported by the housing (10) and comprising a pair of tines (12a) extending in a direction perpendicular to the axis of rotation of the fork (12), between which one or more wires can be inserted in a direction parallel to the axis of rotation of the fork (12), so that rotation of the fork (12) causes the wires to be twisted; and a transmission mechanism (14) housed in the housing and adapted to rotate the fork (12).

Description

Technical Field

[0001] The present invention is generally in the field of electric machines; more particularly, the present invention relates to an apparatus, device, and method for twisting wires used in electric machines. Background Art

[0002] Apparatus for applying electrical windings to slots in metallic components of electrical machines, such as stators and rotors, are known.

[0003] After being wound around two parallel vertical supports, the conductors are inserted into the slots of the motor. However, in this configuration, the windings are difficult to handle, especially as they have frayed ends and are difficult to converge and insert into the insulating sheath.

[0004] A device for inserting and twisting conductors into slots of an electric machine is known from document EP 1 376 828 A1.

[0005] However, the conductors described in the document are in the form of strips or mats. Therefore, they are not wires (which, in the application described in this document, should be clearly understood as conventional, round-cross-section, filamentary, flexible elements, which are wound around each other and inserted into a tubular insulating sheath).

[0006] Furthermore, the above-mentioned prior art document describes a process for inserting these strips into the slots of the stator, whereas the problem underlying the present invention is essentially to facilitate the insertion of the wiring harness into the insulating sheath. Summary of the Invention

[0007] To achieve this, the twisting device according to the invention includes a rotating fork with which the taut wire bundle can be grasped and, by rotating the fork, twisted to converge and appropriately compact the wires before cutting. This makes it easier to handle the wire ends after insertion into the stator slots and cutting, as the wire ends are spread out and dispersed, since there is no need for an operator to converge and twist the individual wire bundles.

[0008] However, in the aforementioned prior art documents, the conductors are already cut and sheathed, and those skilled in the art would not twist them to allow them to be inserted into the insulating sheath. In fact, the only way to insert the strip into the machine is that it has already been cut and pre-formed, and thus, when the strip is inserted, it is already sheathed in its corresponding insulator. It is also obvious that twisting the strip before inserting it into the insulator will not allow the strip to fit over the insulator.

[0009] Thus, the device and the method according to the invention allow easier handling of the wire once it has been inserted into the slot of the electric machine, for example into the corresponding insulating sheath.

[0010] According to an aspect of the invention, the above and other objects and advantages are achieved by means of an apparatus, a device and a method having the features defined in the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The functions and structural features of some preferred embodiments of the apparatus, device, and method according to the present invention are now described. Please refer to the accompanying drawings, in which:

[0012] Figure 1 is a schematic perspective view of a device including a fork for twisting electric motor winding wires according to an embodiment of the present invention;

[0013] Figure 2 According to an embodiment of the present invention Figure 1 Schematic cross-sectional view of the device in which the transmission gear of the rotational movement of the fork is visible;

[0014] Figure 3 is included Figure 1 and Figure 2 A schematic perspective view of an apparatus of the invention, wherein, during a step of the twisting process, the apparatus is retracted to a distal position relative to a wire bundle tightened from a winding to be placed in an electric machine component;

[0015] Figure 4 It is a step in the twisting process Figure 3 a schematic perspective view of the apparatus in which the device is moved to a proximal position relative to the tensioned wire bundle; and

[0016] Figure 5 It is a step in the twisting process Figure 3 Schematic perspective view of the apparatus in which the device is engaged with a tensioned wire bundle. DETAILED DESCRIPTION

[0017] Before describing various embodiments of the present invention in detail, it should be understood that the present invention is not limited in its application to the structural details and component arrangements presented in the following description or illustrated in the accompanying drawings. The present invention may adopt other embodiments and may be implemented or realized in various ways in practice. It should also be understood that the wording and terminology are for descriptive purposes only and should not be construed as limiting.

[0018] With reference to the figures by way of example, an apparatus 20 for twisting wires used in electric machines comprises a device 1 for twisting wires 9 used in electric machines 8 , the device 1 comprising a housing 10 and a fork 12 rotatably supported by the housing 10 .

[0019] The fork 12 includes a pair of tines 12a extending in a direction perpendicular to the rotation axis of the fork 12. One or more wires 9 can be inserted between the pair of tines 12a in a direction parallel to the rotation axis of the fork 12, so that rotation of the fork 12 causes the wires to twist. In other words, a slot is provided between the tines 12a, and one or more wires can be inserted into the slot, so that rotation of the tines 12 causes the wires to twist.

[0020] The gaps between the tines 12a are narrow enough to allow the fork 12 to grip the wire. Suitably, the tines 12a are elastically expandable so that forcibly inserting the wire widens the gaps between the tines 12a, which in turn exert a gripping force on the wire.

[0021] The device 1 further comprises a transmission mechanism 14 housed in the housing and adapted to rotate the fork 12 .

[0022] According to a preferred embodiment (by Figure 2 ), the fork 12 can rotate together with the first gear 14a that meshes with a plurality of intermediate gears 14b, which receive the rotational motion from the pinion 14c.

[0023] Suitably, the pinion 14 c is driven in rotation by a motor 16 integral with the housing 10 .

[0024] According to a preferred embodiment, the tines 12a of the fork 12 each have a beveled end in order to create a guide facilitating the insertion of a wire between these tines 12a.

[0025] The device 20 further includes: a support structure 22, which is fixed relative to a reference plane (e.g., a floor plane); and a sliding member 24, which moves integrally with the device 1 relative to the support structure 22 in a direction perpendicular to the rotation axis of the fork 12, so that the device 1 can move vertically relative to the wire to be twisted.

[0026] Suitably, the slide 24 is movable in three spatial dimensions.

[0027] The method for twisting a wire for use in an electric motor comprises the following steps: providing a device 20 according to one embodiment described above; and providing a component (rotor or stator) of an electric motor 8 and an associated winding 9. The winding 9 is arranged to protrude from a slot of the component of the electric motor 8, i.e., it has not yet been definitively installed.

[0028] Subsequently, one or more wires forming these windings 9 are stretched in a first direction (e.g. Figures 3 to 5 As shown in the embodiment in FIG, it is hooked and pulled in the first direction).

[0029] The device 1 is thus moved in such a way that it is arranged transversely relative to the first direction (e.g. by Figure 4 ), and one or more wires are inserted into the fork 12 of the device 1, which is rotated one or more times around an axis x parallel to the first direction to twist the one or more wires onto itself.

[0030] Suitably, the twisting step is followed by a step of cutting the wire or wires. Due to the special configuration of the apparatus 20, the twisting step can be performed before the cutting step.

[0031] Various aspects and embodiments of the apparatus, device, and method according to the present invention have been described. It should be understood that each embodiment may be combined with any other embodiment. Furthermore, the present invention is not limited to the described embodiments, but may be modified within the scope of the appended claims.

Claims

1. A method for twisting a conductor for use in an electric motor, comprising the following steps: a) providing a device (20), the device comprising: - a device (1), comprising: housing (10); a fork (12) rotatably supported by the housing (10) and comprising a pair of tines (12a) extending in a direction perpendicular to the rotation axis of the fork (12), one or more wires being insertable between the pair of tines (12a) in a direction parallel to the rotation axis of the fork (12), such that rotation of the fork (12) causes the wires to twist; and a transmission mechanism (14) housed in the housing and adapted to rotate the fork (12); - a support structure (22), fixed relative to a reference plane; and - a slide (24) movable integrally with the device (1) relative to the support structure (22) in a direction perpendicular to the axis of rotation of the fork (12), so that the device (1) can be moved perpendicularly relative to the wires to be twisted; b) providing a motor component (8) and associated winding (9) such that the winding (9) extends from a slot in the motor component (8) and is not permanently in place; c) stretching a plurality of conductive wires forming the winding (9) in a first direction; d) moving the device (1) in a manner arranged transversely relative to the first direction; e) inserting the plurality of wires into the fork (12) of the device (1); f) rotating the fork (12) one or more times about an axis parallel to the first direction to twist the one or more wires onto itself; g) cutting the plurality of wires; and h) inserting the plurality of wires into the insulating sheath.

2. The method according to claim 1, wherein Step b) is preceded by the following step: after being wound around two parallel vertical supports, the conductor is inserted into the slot of the electric machine.

3. The method according to claim 1 or 2, wherein: The slide (24) is movable along three spatial dimensions.

4. The method according to claim 1 or 2, wherein: The fork (12) is movable integrally with a first gear (14a) meshing with a plurality of intermediate gears (14b) which receive their rotational motion from a pinion (14c).

5. The method according to claim 4, wherein The pinion (14c) is driven to rotate by a motor (16) integrated with the housing (10).

6. The method according to claim 1 or 2, wherein: The tines (12a) of the fork (12) each have a beveled end to create a guide for facilitating insertion of the wire between the tines (12a).

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