GB1588847A

GB1588847A - Rotary electric machine

Info

Publication number: GB1588847A
Application number: GB48545/77A
Authority: GB
Original assignee: Ducellier et Cie
Current assignee: Ducellier et Cie
Priority date: 1976-12-22
Filing date: 1977-11-22
Publication date: 1981-04-29
Also published as: ES464709A1; DE2757485A1; FR2375745A1; FR2375745B1

Description

(54) A ROTARY ELECTRIC MACHINE (71) We, DUCELLIER & CIE, a French Body corporate located at Echat 950, 94025 Creteil Cedex, France, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a rotary electric machine and more particularly an alternator for a motor vehicle, of the type including a shaft which turns within bearings held in a support, and which drives a rotor in rotation, a stator held by the support, a brush carrier, a regulator, a rectifying system and a pulley-fan located outside the support.

The majority of known alternator casings of this type are constituted by two casing portions of different shape made by moulding. It is thus necessary to have two different tools to make these two casing portions, and moreover it is indispensible to machine the operating surfaces in order to obtain a surface having suitable dimensions and qualities.

Other known casings are constituted by two identical casing portions obtained by moulding, which lessens the number of moulds and consequently the cost of the alternator, but which does not remove the necessity for subsequent machining of the operating surfaces and dimensions, which makes for high cost.

An object of the present invention is thus. to make a rotary machine, and particularly a vehicle alternator, which is more economic to manufacture than some conventional alternators.

According to the present invention, a rotary electric machine comprises a casing, a shaft which drives a rotor in rotation and which turns within bearings held in portions of the casing, at least one of which casing portions holds a stator and has a brush carrier, a regulator and a rectifying system, secured to the outside thereof, a pulley-fan secured to an end portion of the shaft, the casing portions being identical pressings, each of which has an end wall portion in the centre of which is formed a bearing housing open at both ends to permit the passage through the casing portion of the rotor drive shaft, one of the bearing housings serving to mount the brush carrier which is secured to the end wall of the associated casing portion, which casing portion also includes means for fixing the regulator and the rectifying system, the other casing portion providing an abutment for the pulley-fan, the casing portions including on the periphery of their end wall portions tongues which are bent back substantially perpendicular to the plane of the said end wall portions and which interdigitate with one another when the two casing portions are assembled, so as to constitute the said machine casing.

The invention will now be described, by way of example, with reference to the accompanying drawings in which: Figure 1 shows one form of alternator of the invention; Figure 2 shows in plan view one of the casing portions of the alternator of Figure 1, and Figure 3 shows the casing portion of Figure 2 along the section III-III of Figure 2.

The alternator of Figure 1 is constituted in known manner by a shaft 1 which turns in two bearings 2 and 3, held in casing portions 11 and 12, the shaft driving a rotor 4 in rotation. The shaft has towards one of its ends, collecting tracks 7 and 8 on which wipe brushes 5 and 6, and towards its other end a pulley-fan 9. A stator 10 is held by the two casing portions, and has apertures 26, 27 and 28, one of which acts as a support for a rectifyer system 13 and a brush carrier 14 in which is incorporated a regulator 15. A pair of brackets 16 and 17 are disposed on the outside of the casing portions 11 and 12 in order to permit the alternator to be fixed within a vehicle, and the drive belt to be tightened when the assembly is mounted on the vehicle.

The two casing portions 11 and 12 are made from sheets of steel or aluminium and are identical pressings. They are constituted by an end wall portion 18 which is circular and which may be hollow in shape at 18a as shown in Figure 3, so as to make the casing portion rigid. In the centre of the end wall portion 18 a boss is formed by pressing and serves as the housing 24 for one of the bearings 2 or 3. The housing 24 is open-ended in order to permit the passage of the shaft 1.

Tongues 19 are pressed on the periphery of the end wall portion 18, which are substantially perpendicular to the end wall portion and have two notches 20 and 21, between which the stator 10 is axially held. The free end 23 of the tongues 19 is slightly bent towards the outside of the casing portion. Between the notches 20 and 21 within the casing portion a magnetic screen is disposed between the casing portion and the stator when the pressing is made from a sheet of steel. This magnetic screen (not shown) may be a ring of a magnetic material, or a coating of plastics material such as Teflon (Registered Trade Mark). The fixing brackets 16 and 17 are located between the notches 20 and 21 outside the casing portion. A band 29 then clamps the assembly consisting of the brackets 16, 17 tongues 19 of the casing portions and stator 10. The bearings 2 and 3 are held by bonding or crimping within the housings 24.

The brush carrier 14, in which the regulator 15, preferably of the electronic type, may advantageously be incorporated, is located by the outside of the boss 24 of the casing portion 12 and is fixed by known means on the outer face of the cheek 18 of the casing portion 12. The rectifying system 13 is also fixed on the outer face of the end wall portion 18 of the casing portion 12. It may be advantageous to provide, by pressing on the outside of the end wall portion of the casing portions, indentations 30 in order to fix the negative diodes of the rectifier 13 directly on the casing portion 12. When assembled, the tongues 19 of the casing portion 11 are interdigitated with those of the casing portion 12 and secure the stator 10 between their notches 20 and 21 by snap-engagement. The brackets 16 and 17 are positioned and the band 29 is then tightened and rigidly holds the two casing portions 11 and 12, the stator 10 and the brackets 16 and 17. The casing portion 11 provides an abutment for a hub 9a of the pulley-fan 9 by way of the bearing 2 held in the portion 11. A cover 31 fits onto the casing portion 12 in order to protect the rectifying system 13 and the brush carrier regulator assembly 14-15.

The alternator is thus made is inexpensive to produce and may be adapted to any type of rotary electric machine, such as motors or electric dynamo machines.

WHAT WE CLAIM IS:- 1. A rotary electric machine comprising a casing, a shaft which drives a rotor in rotation and which turns within bearings held in portions of the casing, at least one of which casing portions holds a stator and has a brush carrier, a regulator, and a rectifying system, secured to the outside thereof, a pulley-fan secured to an end portion of the shaft, the casing portions being identical pressings, each of which has an end wall portion, in the centre of which is formed a bearing housing open at both ends to permit the passage through the casing portion of the rotor drive shaft, one of the bearing housings serving to mount the brush carrier, which is secured to the end wall of the associated casing portion, which casing portion also includes means for fixing the regulator and the rectifying system, the other casing portion providing an abutment for the pulley-fan, the casing portions including on the periphery of their end wall portions tongues which are bent back substantially perpendicular to the plane of the said end wall portions and which interdigitate with one another when the two casing portions are assembled, so as to constitute the said machine casing.

2. A rotary electric machine according to Claim 1 wherein a magnetic screen is interposed between the surfaces of the casing portions is in contact with the stator.

3. A rotary electric machine, according to Claim 1 or Claim 2 wherein the casing portions include, by pressing, indentations in order to fix the negative diodes of the rectifier directly on the outer face of the corresponding casing portion.

4. A rotary electric machine, substantially as hereinbefore described, with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. made from sheets of steel or aluminium and are identical pressings. They are constituted by an end wall portion 18 which is circular and which may be hollow in shape at 18a as shown in Figure 3, so as to make the casing portion rigid. In the centre of the end wall portion 18 a boss is formed by pressing and serves as the housing 24 for one of the bearings 2 or 3. The housing 24 is open-ended in order to permit the passage of the shaft 1. Tongues 19 are pressed on the periphery of the end wall portion 18, which are substantially perpendicular to the end wall portion and have two notches 20 and 21, between which the stator 10 is axially held. The free end 23 of the tongues 19 is slightly bent towards the outside of the casing portion. Between the notches 20 and 21 within the casing portion a magnetic screen is disposed between the casing portion and the stator when the pressing is made from a sheet of steel. This magnetic screen (not shown) may be a ring of a magnetic material, or a coating of plastics material such as Teflon (Registered Trade Mark). The fixing brackets 16 and 17 are located between the notches 20 and 21 outside the casing portion. A band 29 then clamps the assembly consisting of the brackets 16, 17 tongues 19 of the casing portions and stator 10. The bearings 2 and 3 are held by bonding or crimping within the housings 24. The brush carrier 14, in which the regulator 15, preferably of the electronic type, may advantageously be incorporated, is located by the outside of the boss 24 of the casing portion 12 and is fixed by known means on the outer face of the cheek 18 of the casing portion 12. The rectifying system 13 is also fixed on the outer face of the end wall portion 18 of the casing portion 12. It may be advantageous to provide, by pressing on the outside of the end wall portion of the casing portions, indentations 30 in order to fix the negative diodes of the rectifier 13 directly on the casing portion 12. When assembled, the tongues 19 of the casing portion 11 are interdigitated with those of the casing portion 12 and secure the stator 10 between their notches 20 and 21 by snap-engagement. The brackets 16 and 17 are positioned and the band 29 is then tightened and rigidly holds the two casing portions 11 and 12, the stator 10 and the brackets 16 and 17. The casing portion 11 provides an abutment for a hub 9a of the pulley-fan 9 by way of the bearing 2 held in the portion 11. A cover 31 fits onto the casing portion 12 in order to protect the rectifying system 13 and the brush carrier regulator assembly 14-15. The alternator is thus made is inexpensive to produce and may be adapted to any type of rotary electric machine, such as motors or electric dynamo machines. WHAT WE CLAIM IS:-

1. A rotary electric machine comprising a casing, a shaft which drives a rotor in rotation and which turns within bearings held in portions of the casing, at least one of which casing portions holds a stator and has a brush carrier, a regulator, and a rectifying system, secured to the outside thereof, a pulley-fan secured to an end portion of the shaft, the casing portions being identical pressings, each of which has an end wall portion, in the centre of which is formed a bearing housing open at both ends to permit the passage through the casing portion of the rotor drive shaft, one of the bearing housings serving to mount the brush carrier, which is secured to the end wall of the associated casing portion, which casing portion also includes means for fixing the regulator and the rectifying system, the other casing portion providing an abutment for the pulley-fan, the casing portions including on the periphery of their end wall portions tongues which are bent back substantially perpendicular to the plane of the said end wall portions and which interdigitate with one another when the two casing portions are assembled, so as to constitute the said machine casing.