WO2015079383A1

WO2015079383A1 - Electric motor

Info

Publication number: WO2015079383A1
Application number: PCT/IB2014/066323
Authority: WO
Inventors: Andrea BOLLETTA
Original assignee: Motovario S.P.A.
Priority date: 2013-11-27
Filing date: 2014-11-25
Publication date: 2015-06-04
Also published as: ITBO20130652A1

Abstract

An electric motor which comprises a casing (2), a driving shaft (3), at least partly housed in the casing (2), which extends outside the casing (2) at least at a first end (4) of the shaft (3) and at least one accessory unit (6) connected to the first end (4) of the driving shaft (3); the electric motor also comprises disassemblable connecting means (10) for connecting the accessory unit (6) to the first end (4) of the shaft (3) to allow removal and/or fitting of the accessory unit (6), passing from at least a first to a second configuration.

Description

DESCRIPTION

ELECTRIC MOTOR

Technical field

This invention relates to an electric motor.

Background art

It is known that electric motors comprise a casing for containing a rotor and a respective stator winding.

The rotor is supported by a driving shaft, rotating about its own main axis of rotation, which extends outside the casing to drive the rotation of auxiliary devices connectable to it, in particular at one of the ends of the shaft.

To implement the functional capacities of an electric motor manufacturers install various types of accessory units which characterise the electric motor. For example, a cooling fan, motor brake, encoder, etc. These are usually installed at the end of the driving shaft opposite to the end which is used for connection to the auxiliary devices.

The accessory units are normally coupled to the driving shaft by interference fit or by rigid connections, to prevent accidental uncoupling of the accessory units during rotation of the driving shaft.

However, such couplings do not allow any possibility of variation of the accessory units of the electric motor, constraining its use.

Therefore, the need is felt to make an electric motor which can be either customisable by the user, that is to say, whose accessory units can be fitted or removed depending on user requirements.

Disclosure of the invention

One aspect of this invention is that of making an electric motor comprising a casing, a driving shaft, at least partly housed in the casing, which extends outside the casing at least at a first end of the shaft, and at least one accessory unit connected to the first end of the driving shaft. The electric motor is characterised in that it comprises disassemblable connecting means for connecting the accessory unit to the first end of the shaft, for allowing removal and/or fitting of the accessory unit for passing from at least a first to a second configuration.

Advantageously, using the disassemblable connecting means it is possible to easily vary the configuration of the electric motor, removing or fitting one or more accessory units. Brief description of drawings

Further features and advantages of this invention are more apparent in the detailed description below, with reference to a preferred, non-limiting, embodiment of an electric motor as illustrated in the accompanying drawings, in which:

- Figure 1 is a schematic perspective view of an electric motor in accordance with this invention;

- Figure 2 is a schematic lateral section of the electric motor of Figure 1 with some parts cut away to better illustrate others;

- Figure 3 is a schematic lateral section of a first embodiment of the electric motor in accordance with this invention;

- Figure 4 is a schematic lateral section of a second embodiment of the electric motor in accordance with this invention.

Detailed description of preferred embodiments of the invention

With reference to the accompanying drawings, the numeral 1 denotes an electric motor according to this invention.

The electric motor 1 comprises a casing 2 and a driving shaft 3 at least partly housed in the casing 2.

The driving shaft 3 rotates about its own axis 3a of rotation.

The electric motor 1 comprises a stator winding or stator 19 and a rotor 20 surrounded by the stator 19, which are housed inside the casing 2. The rotor 20 surrounds the driving shaft 3 which in that way is driven to rotate about its own axis 3a of rotation.

The driving shaft 3 extends outside the casing 2.

In particular, at least a first end 4 of the shaft 3 extends outside the casing 2.

Preferably, the driving shaft 3 comprises respective first and second ends 4 and 5 which extend outside the casing 2 from respective lateral faces 2b of the casing 2, one opposite to the other, as shown in Figure 2.

The term lateral faces 2b refers to the faces of the casing 2 which are transversal to the axis 3a of rotation of the shaft 3.

The second end 5 of the shaft 3 is designed to transmit the rotary motion of the driving shaft 3 to an auxiliary device, not illustrated, connectable to the second end 5.

The electric motor 1 comprises at least one accessory unit 6 connected to the first end 4 of the driving shaft 3.

The term accessory unit 6 refers to a mechanical or electronic unit which implements the potential of the electric motor 1 , in addition to simple transmission of the motion of the driving shaft 3.

In particular, with reference to Figures 3 and 4, electric motors 1 according to the first and second embodiments both have a first accessory unit 7 formed by a cooling fan of the electric motor 1 .

The first accessory unit 7 defines a first configuration of the electric motor 1 .

The first embodiment of the electric motor 1 comprises a second accessory unit 8 formed by a braking unit of the driving shaft 3.

The second accessory unit 8 defines a second configuration of the electric motor 1 .

The second embodiment of the electric motor 1 is distinguished from the first embodiment in that it comprises a third accessory unit 9 formed by an encoder of the driving shaft 3.

The third accessory unit 9 defines a third configuration of the electric motor 1 .

It should be noticed that in alternative embodiments the electric motor 1 may also comprise only one accessory unit 6, for example the cooling fan 7, or it may comprise further accessory units not illustrated.

Advantageously, the electric motor 1 comprises disassemblable 10 connecting means for connecting the accessory unit 6 to the first end 4 of the shaft 3 to allow removal and/or fitting of the accessory unit 6 and to pass at least from a first configuration to a second configuration.

In this way, the user of the electric motor 1 can modify the configurations of the electric motor 1 according to his requirements.

For example, it is possible to pass from the first to the second embodiment by removing the braking unit 8 of the driving shaft 3 and fitting the encoder 9 in place of the braking unit 8.

Advantageously, the electric motor 1 may be used for a plurality of uses, by varying its accessory units 6.

The disassemblable connecting means 10 comprise at least one extension element 1 1 for extending the driving shaft 3, connectable to the first end 4 of the driving shaft 3.

The extension element 1 1 connected to the driving shaft 3 is coaxial with the shaft 3.

Consequently, the extension element 1 1 , once connected to the driving shaft 3, extends along the axis 3a of rotation of the shaft 3.

Advantageously, the extension element 1 1 allows the length of the driving shaft 3 to be extended at the outfeed of the casing 2, allowing the fitting of one or more accessory units 6.

To connect the extension element 1 1 to the driving shaft 3, one out of the two parts that are the first end 4 of the driving shaft 3 and the extension element 1 1 comprises a seat 12 for receiving at least part of the other. The receiving seat 12 is in the form of a hole made in the first end 4 of the driving shaft 3.

In particular, in the embodiment illustrated, the first end 4 of the driving shaft 3 comprises the receiving seat 12 for receiving at least part of the extension element 1 1.

The size of the receiving seat 12 is greater than that of the portion of the extension element 1 1 inserted in the seat 12.

In other words, the extension element 1 1 and the driving shaft 3 are connected by means of a coupling with play.

To lock the coupling of the driving shaft 3 with the extension element 1 1 , the disassemblable connecting means 10 comprise at least a fixing element 13 for fixing the extension element 1 1 to the first end 4 of the driving shaft 3.

In particular, the fixing element 13 acts along a direction orthogonal to the direction of the axis 3a of the driving shaft 3 and of the extension element 1 1 .

Advantageously, the fixing element 13 takes up the radial play between the receiving seat 12 of the first end 4 of the driving shaft 3 and the extension element 1 1.

The extension element 1 1 , in particular the portion inserted in the receiving seat 12, and the driving shaft 3 respectively comprise insertion elements 14, 15 for insertion of the fixing element 13 which are aligned with one another.

In particular, the extension element 1 1 comprises a respective insertion seat 14 for insertion of the fixing element 13.

The driving shaft 3 comprises a respective insertion hole 15 for insertion of the fixing element 13.

The insertion hole 15 in the driving shaft is a through hole. In particular, it is in communication with the hole 12 for receiving the extension element 1 1 .

The seat 14 and the insertion hole 15 form the above-mentioned insertion elements

In particular, the insertion elements 14 and 15 are threaded. More precisely, the fixing element 13 is connected by a male-and-female screw type coupling to the extension element 1 1 and the driving shaft 3. In this way, the possibility of the extension element 1 1 slipping out of the driving shaft 3 is avoided.

In the preferred embodiment, the fixing element 13 is in the form of a grub screw which engages by screwing in the respective hole 15 and in the respective seat 14 which are aligned with each other.

To prevent spontaneous unscrewing of the fixing element 13 following rotation of the driving shaft 3, the electric motor 1 comprises a locking sleeve 16 for locking the fixing element 13.

The sleeve 16 is coupled at least to the portion of the first end 4 of the driving shaft 3 comprising the insertion hole 15 for insertion of the fixing element 13, in such a way as to radially retain the fixing element 13 inserted in the hole 15.

In other words, the locking sleeve 16 extends at least on the portion of the first end 4 of the driving shaft 3 so as to lock the fixing element 13 in such a way as to prevent it from coming out radially by means of the part of its inner surface 16b.

More precisely, the locking sleeve 16 is connected to the first end 4 of the driving shaft 3 and to the extension element 1 1 by a coupling with a tab 17.

Advantageously, the coupling with a tab 17 allows removal or fitting of the locking sleeve 16 every time the user need to uncouple or couple the extension element 1 1 at the first end 4 of the driving shaft 3 so as to pass from one configuration to the other.

The locking sleeve 16 comprises a receiving recess 19 for receiving the tab 17.

The first end 4 of the driving shaft 3 and the extension element 1 1 respectively comprise portions of a seat 18 for housing the tab 17.

Preferably, the seat 18 for housing the tab 17 is positioned on a side diametrically opposed to the insertion elements 14 and 15 for insertion of the fixing element 13.

The tab 17 is inserted in the recess 19 in the sleeve 16 and in the housing seat 18 made on the first end 4 of the driving shaft 3 and on the extension element 1 1 .

With reference to the first embodiment of the electric motor 1 illustrate in Figure 3, the cooling fan 7 is supported by the extension element 1 1 .

Advantageously, the user who owns an electric motor which is not ventilated can make a ventilated electric motor 1 by coupling the cooling fan 7 to the extension element 1 1 and fitting the extension element 1 1 on the first end 4 of the driving shaft 3 by means of the disassemblable connecting means 10.

Advantageously, according to the first embodiment of the electric motor 1 the braking unit 8 of the driving shaft 3 comprises said locking sleeve 16. With reference to the second embodiment of the electric motor 1 illustrated in Figure 4, the encoder 9 is supported by the extension element 1 1 .

Advantageously, the user who wants to install the encoder 9 in an electric motor 1 couples the encoder 9 to the extension element 1 1 , then fits the extension element 1 1 on the first end 4 of the driving shaft 3 by means of the disassemblable connecting means 10.

Finally, it should be noticed that both the first and second embodiments of the electric motor 1 comprise a cap 21 for covering the accessory units 6, in particular for the first and second accessory units 7 and 8 according to the first embodiment and for the first and third accessory units 7 and 9 according to the second embodiment.

Advantageously, the disassemblable connecting means 10 allow the passage at least from a first configuration of the electric motor 1 to a second configuration by fitting or removing one or more accessory units 6 at the first end 4 of the driving shaft 3.

The disassemblable connecting means 10 also allow significant limiting of the longitudinal dimensions of the electric motor 1 , according to the direction of the axis 3a of rotation of the driving shaft 3. Advantageously, the electric motor according to this invention allows the operations for removal and/or fitting of the one or more accessory units 6 to be carried out while avoiding the use of presses or automatic screwing devices, since the couplings between the accessory units 6 and the connecting means 10 are couplings with play and if necessary unscrewing of the fixing element 13 is prevented geometrically.

Claims

1 . An electric motor comprising a casing (2), a driving shaft (3), at least partly housed in the casing (2), extending outside the casing (2) at least at a first end (4) of the shaft (3) and at least one accessory unit (6) connected to the first end (4) of the driving shaft (3); the electric motor being characterised in that it comprises disassemblable connecting means (10) for connecting the accessory unit (6) to the first end (4) of the shaft (3) to allow removal and/or fitting of the accessory unit (6), passing from at least a first to a second configuration of the electric motor (1 ).

2. The electric motor according to claim 1 , characterised in that the disassemblable connecting means (10) comprise at least one extension element (1 1 ) for extending the driving shaft (3) connectable to the first end (4) of the driving shaft (3).

3. The electric motor according to claim 2, characterised in that one out of the two parts that are the first end (4) of the driving shaft (3) and the extension element (1 1 ) comprises a seat (12) for receiving at least part of the other.

4. The electric motor according to claim 3, characterised in that the first end (4) of the driving shaft (3) comprises a seat (12) for receiving at least part of the extension element (1 1 ).

5. The electric motor according to any one of claims 2 to 4, characterised in that the extension element (1 1 ) and the driving shaft (3) are connected by means of a coupling with play.

6. The electric motor according to any one of claims 2 to 4, characterised in that the disassemblable connecting means (10) comprise at least a fixing element (13) for fixing the extension element (1 1 ) to the first end (4) of the driving shaft (3).

7. The electric motor according to claim 6, characterised in that the fixing element (13) acts along a direction orthogonal to the direction of the axis (3a) of the driving shaft (3) and of the extension element (1 1 ).

8. The electric motor according to claim 6 or 7, characterised in that the extension element (1 1 ) and the driving shaft (3) respectively comprise insertion elements (14, 15) for insertion of the fixing element (13) which are aligned with one another.

9. The electric motor according to any one of claims 6 to 8, characterised in that the fixing element (13) is connectable by means of a male-and- female screw type coupling to the extension element (1 1 ) and the driving shaft (3).

10. The electric motor according to any one of claims 6 to 9, characterised in that it comprises a locking sleeve (16) for locking the fixing element (13).

1 1 . The electric motor according to claim 10, characterised in that the locking sleeve (16) is coupled at least to the portion of the first end (4) of the driving shaft (3) comprising the insertion element (15) for insertion of the fixing element (13) in such a way as to radially retain the fixing element (13) inserted in the hole (15).

12. The electric motor according to claim 1 1 , characterised in that the locking sleeve (16) is connected to the first end (4) of the driving shaft (6) and to the extension element (1 1 ) by a coupling with a tab (17).

13. The electric motor according to any one of claims 2 to 12, characterised in that it comprises a first accessory unit (7) comprising a cooling fan supported by the extension element (1 1 ); the first accessory unit (7) defining a first configuration.

14. The electric motor according to any one of claims 10 to 13, characterised in that it comprises a second accessory unit (8) comprising a braking unit of the driving shaft (3) comprising said locking sleeve (16); the second accessory unit (8) defining a second configuration.

15. The electric motor according to any one of claims 2 to 14, characterised in that it comprises a third accessory unit (9) comprising an encoder supported by the extension element (1 1 ); the third accessory unit (9) defining a third configuration.