GB2105117A - Improvements in or relating to generators, particularly three-phase generators. - Google Patents

Abstract

A generator, particularly a three- phase generator, has an annular stator (1) and a winding which is sub-divided into two individual layer windings (4, 5) inserted into slots in the stator, and an annularly extending cooling tube (9) disposed between coil ends (7, 7) of the individual layer winding and connected to a cooling system. Alternatively, cooling may be effected by a plurality of tubes (11-14) disposed between the coil ends (7, 8), and connected to a cooling system. <IMAGE>

Description

SPECIFICATION Improvements in or relating to generators, particularly three-phase generators The present invention relates to generators, particularly three-phase generators for vehicles.

One form of three-phase generator has an at least approximately annular stack of stator laminations and the coil ends of the winding introduced into the stator project from the end faces thereof, with cooling tubes being provided at the coil ends.

German Utility Model 80 27 381.0 recommends the use of cooling rings and cooling fins inserted into the winding but these preclude the mechanical manufacture of the windings.

According to the present invention there is provided a generator, particularly a three-phase generator, having an at least approximately annular stack of stator laminations, in which windings disposed in the stator are sub-divided into two individual layer windings and the coil ends of the windings project from the end faces of the stator, and at least one cooling tube is disposed between coil ends associated respectively with the individual layer windings and extends annularly in the circumferential direction of the stator and substantially coaxially therewith and is connected to a closed cooling system.

The present invention can therefore provide a cooling arrangement which permits mechanical manufacture of the windings.

Preferably the cooling system has forced circulation of a liquid coolant.

The invention will be further described by way of example with reference to the accompanying draw inns which illustrate two embodiments of the invention and in which: Figure 1 is an axial longitudinal section through a wound stator of a three-phase generator, and.

Figure 2 is an axial plan view of the stator, partially in a unwound state and partially in section through the winding and a cooling tube.

The stator 1 illustrated in the drawings comprises a stack of stamped sheet-metal laminations and is held together at its outer circumference in a known manner by welding ribs or the like. Three threephase windings (not shown in detail) are circumferentially distributed around the bore side 2 of the stator 1. Each of these windings is sub-divided into two individual layer windings, that is to say, a first individual layer winding 4 resting on the bottoms of the slots 3, and a second individual layer winding 5 resting on the individual layer winding 4 in the slots.

The coil ends of these individual layer windings are designated 7 and 8 in Figures 1 and 2.

Referring to the left hand half of Figure 1, a cooling tube 9, originally having a circular cross section, is disposed between the two winding coil ends 7 and 8 and is bent to form a ring extending along the periphery of the stator 1 and concentrically surrounds the stator axis 10. The cross section of the tube 9 has been deformed to an oval to elliptical cross section by radial squeezing pressure, the longitudinal axis of the cross section, shown in Figure 1, extending parallel to the axis of rotation 10.

The tube 9 is connected to a forced circulation system, such as the oil circuit of an internal combustion engine which drives the three-phase generator.

The oil flowing in the tube 9 absorbes a considerable proportion of the heat produced by the current in the windings, so that the generator can be operated with a substantially higher output relative to the specific iron and copper volume.

A modified embodiment is illustrated in the right hand half of Figure 1 in which fourturns 11 to 14 of a copper tube 15 of uniform cross section are disposed between the coil ends, also designated 7 and 8, of the two individual layer windings 4 and 5. The copper tube 15 can be connected to the lubricating oil circuit of an internal combustion engine or to some other forced circulation system. The illustrated turns 11 to 14 have uniform diameters and, in a further modification, can comprise individual turns whose ends can be interconnected and which can be connected to a forced circulation system for a coolant.

1. A generator, particularly a three-phase generator, having an at least approximately annular stack of stator laminations, in which windings disposed in the stator are sub-divided into two individual layer windings and the coil ends of the windings project from the end faces of the stator, and at least one cooling tube is disposed between coil ends associated respectively with the individual layer windings and extends annularly in the circumferential direction of the stator and substantially coaxially therewith and is connected to a closed cooling system.

2. A generator as claimed in claim 1, in which the cooling system has forced circulation of a liquid coolant.

3. A generator as claimed in claim 1 or 2, in which the cooling tube has an oval or elliptical flow-through cross-section whose longitudinal axis extends substantially parallel to the axis of the stator.

4. A generator as claimed in claim 1 or 2, in which a plurality of turns of one of a plurality of cooling tubes are formed with substantially equal diameters coaxially of the stator axis and are disposed between the coil ends of the individual layer windings at each end face of the stator.

5. A generator, particularly, a three-phase generator, constructed and arranged and adapted to operate substantially as hereinbefore particularly described with reference to and as illustrated in the accompanying drawings.

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

Claims (5)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements in or relating to generators, particularly three-phase generators The present invention relates to generators, particularly three-phase generators for vehicles. One form of three-phase generator has an at least approximately annular stack of stator laminations and the coil ends of the winding introduced into the stator project from the end faces thereof, with cooling tubes being provided at the coil ends. German Utility Model 80 27 381.0 recommends the use of cooling rings and cooling fins inserted into the winding but these preclude the mechanical manufacture of the windings. According to the present invention there is provided a generator, particularly a three-phase generator, having an at least approximately annular stack of stator laminations, in which windings disposed in the stator are sub-divided into two individual layer windings and the coil ends of the windings project from the end faces of the stator, and at least one cooling tube is disposed between coil ends associated respectively with the individual layer windings and extends annularly in the circumferential direction of the stator and substantially coaxially therewith and is connected to a closed cooling system. The present invention can therefore provide a cooling arrangement which permits mechanical manufacture of the windings. Preferably the cooling system has forced circulation of a liquid coolant. The invention will be further described by way of example with reference to the accompanying draw inns which illustrate two embodiments of the invention and in which: Figure 1 is an axial longitudinal section through a wound stator of a three-phase generator, and. Figure 2 is an axial plan view of the stator, partially in a unwound state and partially in section through the winding and a cooling tube. The stator 1 illustrated in the drawings comprises a stack of stamped sheet-metal laminations and is held together at its outer circumference in a known manner by welding ribs or the like. Three threephase windings (not shown in detail) are circumferentially distributed around the bore side 2 of the stator 1. Each of these windings is sub-divided into two individual layer windings, that is to say, a first individual layer winding 4 resting on the bottoms of the slots 3, and a second individual layer winding 5 resting on the individual layer winding 4 in the slots. The coil ends of these individual layer windings are designated 7 and 8 in Figures 1 and 2. Referring to the left hand half of Figure 1, a cooling tube 9, originally having a circular cross section, is disposed between the two winding coil ends 7 and 8 and is bent to form a ring extending along the periphery of the stator 1 and concentrically surrounds the stator axis 10. The cross section of the tube 9 has been deformed to an oval to elliptical cross section by radial squeezing pressure, the longitudinal axis of the cross section, shown in Figure 1, extending parallel to the axis of rotation 10. The tube 9 is connected to a forced circulation system, such as the oil circuit of an internal combustion engine which drives the three-phase generator. The oil flowing in the tube 9 absorbes a considerable proportion of the heat produced by the current in the windings, so that the generator can be operated with a substantially higher output relative to the specific iron and copper volume. A modified embodiment is illustrated in the right hand half of Figure 1 in which fourturns 11 to 14 of a copper tube 15 of uniform cross section are disposed between the coil ends, also designated 7 and 8, of the two individual layer windings 4 and 5. The copper tube 15 can be connected to the lubricating oil circuit of an internal combustion engine or to some other forced circulation system. The illustrated turns 11 to 14 have uniform diameters and, in a further modification, can comprise individual turns whose ends can be interconnected and which can be connected to a forced circulation system for a coolant. CLAIMS

1. A generator, particularly a three-phase generator, having an at least approximately annular stack of stator laminations, in which windings disposed in the stator are sub-divided into two individual layer windings and the coil ends of the windings project from the end faces of the stator, and at least one cooling tube is disposed between coil ends associated respectively with the individual layer windings and extends annularly in the circumferential direction of the stator and substantially coaxially therewith and is connected to a closed cooling system.

2. A generator as claimed in claim 1, in which the cooling system has forced circulation of a liquid coolant.

3. A generator as claimed in claim 1 or 2, in which the cooling tube has an oval or elliptical flow-through cross-section whose longitudinal axis extends substantially parallel to the axis of the stator.

4. A generator as claimed in claim 1 or 2, in which a plurality of turns of one of a plurality of cooling tubes are formed with substantially equal diameters coaxially of the stator axis and are disposed between the coil ends of the individual layer windings at each end face of the stator.

5. A generator, particularly, a three-phase generator, constructed and arranged and adapted to operate substantially as hereinbefore particularly described with reference to and as illustrated in the accompanying drawings.