JP2002521994A - Electric machine - Google Patents

Abstract

(57) Abstract: In an electric machine, such as an electric motor or a generator, having a casing holding rotatable components, air structured and arranged to allow a flow of air over the outside of the machine. An introduction means is provided. The air introduction means may be an extension of the fan housing or in the form of a protective hood that may be secured to the fan housing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

【Technical field】

The present invention relates to the technology of electric machines, and in particular, to AC motors. It is known that electric machines generate unwanted heat during operation, for example, due to the resistance of the windings and due to friction in the bearings. It is also known to provide a cooling means, such as a fan, for blowing air through a cooling duct. For example, GB 215987B discloses an AC motor having a cooling duct partially through the stator and another portion through the rotor.

One object of the present invention is to allow for alternative or additional cooling. According to the invention, the electric machine is provided with air introduction means arranged and arranged so as to be able to send a flow of air over the outside of the machine.

[0003] The air introduction means may cover at least a part of the outside of the machine and may be an extended part of the fan housing or comprise a protective hood (cowl) secured to the fan housing. The protective hood extends from a fan housing located at one end of the machine and over at least a portion outside the machine, and
For example, a gap such as a passage is provided between the protective hood and the outside.

[0004] The protective hood can be secured to any suitable part of the machine. For example, if the machine consists of an AC motor having a stator and a rotor each with a stack, the protective hood may be mounted on the stator stack at one end of the motor, on a pressure plate holding the stator stack together, or on a bracket. Can be fixed.

[0005] The air introduction means may comprise a frusto-conical or cylindrically shaped air deflector disposed within the fan housing. The baffle can be integrally formed in the housing or attached to the housing.

[0006] The air introduction means, in particular the protective hood or the baffles, also feed air, for example through the at least one hole formed in the stator stack, in the rotor stack and / or between the stator and the rotor. be able to.

[0007] The air introduction means may comprise at least one projection fixed to or formed on the outside of the machine, or arranged immediately adjacent to the outside of the machine, so that the cooling air is provided on its outer surface. To "rub". The projections define one or more passages for air to pass through, which passages may be integrally formed with a vent cap, end bracket, pressure plate, or a portion or all of the laminate.

For example, a ventilation cap for protecting the winding of the stator can be provided so that the winding can be covered at each end of the stator. This vent cap can be connected to a bracket, pressure plate or the stator itself at one end.

A terminal board can be provided that is completely enclosed within one of the two brackets. The terminal board is supported by one of the two brackets and can be internally secured to a portion of a bearing on which a shaft supporting the rotor rotates.

Next, an embodiment of the present invention, that is, an AC induction motor will be described as an example only with reference to the accompanying drawings. The AC induction motor shown in the drawings, in particular in FIG.
5, a rotor 10 mounted on a shaft 11 rotatable about an axis OO in bearings 12, 13 arranged in one of each one of the two end brackets 14, 15, respectively. And a laminated stator 16 held between two pressure plates 17 and 18 for supporting the same.

The rotor 10 comprises a plurality of circular or convex pole stacks stamped from electrical steel and held between end rings 19, 20. Slots (not shown) are provided in the laminate and extend radially inward from the outer periphery of the laminate. A conductor bar 21 is formed in the slot, and the end rings 19, 20 and the conductor bar 21 are formed from an aluminum alloy by die casting to form a known squirrel cage structure. The rotor laminated body is provided with a plurality of circumferentially spaced cooling ducts 22, one of which is shown in FIG. The laminated rotor 10 and the end rings 19, 20 of the rotor are all fixed to the shaft 11 so that they can rotate with the shaft 11.

The stator 16 has no wrapping shells and comprises a plurality of laminates, each of which is stamped and formed from electrical steel and has the shape particularly illustrated in FIG. . Each of the stator laminations is generally square, but has a generally octagonal shape with four corners removed so that the four sides are much longer than the other four sides. ing. These laminates are provided with eight cooling ducts 24 each having a generally triangular outer shape. The cooling ducts are arranged in pairs,
The pair is adjacent to each short side. The stack is held between the pressure plates 17, 18 and the assembly extends together through cooling ducts 24 in the stator stack and through rods 25, which extend through corresponding ducts 29 in the pressure plate. Strongly held. The end of the rod is threaded and a nut 28 is provided for tightening against the pressure plates 17 and 18, one end of the rod is headed and the other end is tightened. A nut can be provided. Alternatively, the stator stack may be securely held between the pressure plates by cleats or welding. Each of the pressure plates is also provided with a cooling duct 29 substantially the same size and shape as the cooling duct 24 of the stator stack and aligned with the cooling duct 24.

As can be seen from FIG. 2, the stator stack includes a central circular hole 33 in which the rotor rotates, and a plurality of slots 34 extending radially from the circular hole. These slots are filled with the stator windings 35 shown in FIG.

Two end brackets 14, 15 having the same generally rectangular shape and dimensions as the pressure plates 17, 18 in the stator 10 are secured to each one of the pressure plates. Each of the end brackets 14, 15 has one end portions 30, 31 extending perpendicular to the axis 11. Each of the one end portions 30, 31 holds and supports bearings 12, 13 to rotatably support the shaft. An end portion 30 (left side in FIG. 1) of the bracket 14 at one end has a terminal board in the chamber formed by the end bracket 14, which also has a bearing 12.
Has a terminal mounted on an adapter plate that functions as an end support for. A connecting lead (not shown) from the stator winding 35 is connected to a protective hood 1 for winding protection.
Extending directly through 38 orifices 37 to the terminal board, the winding protection hood is located in the end bracket and is also connected to the pressure plate 17. The shaft extends through the central opening 39 of the protective hood. Cables (not shown) for supplying power from an external power supply to the terminal board extend through grounds (not shown) in appropriate portions of the end brackets 14,15. Providing the terminal board in the chamber of the end bracket eliminates the need for a conventional terminal box located outside and that the box is in the proper position (top, right or left). To solve the problems that actually occur.

An opening 40 is provided in the other end portion 31 of the other end bracket 15 (the right side in FIG. 1), through which the cooling air is disposed beyond the bracket 15. It can be supplied from the fan 41. The fan 41 is electrically operated independently of the AC motor, but may alternatively be mounted on the side.

The fan 41 is arranged to be rotatable about the same axis 0-0 as the shaft 11 and is arranged in a housing 69 made of molded plastic or assembled material. The housing 69 has a mesh 4 on the end wall 43 perpendicular to the axis 0-0.
2 to allow air to be drawn through this mesh 42 and biased generally axially over the exterior of the motor and through various cooling ducts. As can be seen from FIG. 2, the housing has substantially the same cross-sectional shape as the end bracket 15, but has a horizontally long top side 44 and two vertical long sides 45,46.
And four diagonal short sides 4 larger than the corresponding sides of the end bracket 15
7, 48, 49, 50, pressure plates 17, 18 and a stator 16. The horizontal top long side 44, the two vertical long sides 45, 46 and the upper short sides 47, 48 are all extended, especially as shown in FIG. A protective hood 60 covering the side and the two sides is formed. A long horizontal lower portion where a gap is formed between the inner surface of the protective hood and the adjacent side of the bracket, but where the edge 52 of the housing slightly overlaps the bottom of the end bracket 15 No void is formed in 51. Alternatively, a small gap may be formed in the long horizontal lower portion 51 so that the edge 52 does not overlap the bottom of the end bracket 15. A short cylindrical baffle 54 is molded with or connected to the interior of the end wall 43 of the fan housing. This baffle surrounds the fan blade. The radially inner surface 55 of the deflector is frusto-conical to help guide air toward the motor.

The two end brackets 14, 1 of the pressure plates 17, 18 and the stacked stator 16
On the long side of 5, all two projections 53, 56 are provided. The projections are arranged in a line parallel to the axis 0-0 of the motor, and function as a guide for air blown by the fan.
And axially along the outer surface of the motor, in particular along the stator 16. In this way, a passage for guiding air is formed between adjacent protrusions.

Protrusions 56 at the base provide elongated legs for the motor to sit on the horizontal support surface and a small edge 52 on the lower side 51 due to the lack of a protective hood at the base. Unless a gap is formed, no air is guided from the fan.

In use, air is drawn by the fan 41 through the mesh 42 of the housing 69 and between the protrusions 53 (and the protrusions 56 if a small gap is formed in the edge 52 of the lower side 51). Axially over the surface of the motor through the passage of
Through the apertures 40 in the end bracket and then through the air gap between the rotor duct, stator and rotor or through the pressure plate and stator ducts 29,24. The air can flow in the opposite direction.

Similar to the protective hood 138 shown covering the left winding, a protective hood for protecting the winding can be provided so as to cover the right stator winding shown in FIG.

In one variant, the projections 5 on the top and sides of the right end bracket
3 is omitted. Instead, a corresponding projection 70 is molded with or fixed to the interior of the hood, as can be seen in FIG.

The present invention is applicable to any other type of electrical machine having a stacked stator frame design, both AC and DC. This includes cylindrical, convex and non-convex pole stator / rotors and different numbers of pole and phase windings.

[Brief description of the drawings]

FIG. 1 is a longitudinal section through an electric machine, in this case an AC induction motor according to the invention.

FIG. 2 is a sectional view of the stator laminate pack taken along line II-II of FIG. 1;

FIG. 3 is a perspective view of a stator laminate pack.

FIG. 4 is a perspective view of a pressure plate.

FIG. 5 is a perspective view of a modification of the fan and the protective hood.

──────────────────────────────────────────────────続 き Continuation of front page (81) Designated country EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, IT, LU, MC, NL, PT, SE ), OA (BF, BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, GM, KE, LS, MW, SD, SL, SZ, UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY , CA, CH, CN, CU, CZ, DE, DK, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, JP , KE, KG, KP, KR, KZ, LC, LK, LR, LS, LT, LU, LV, MD, MG, MK, MN, MW, MX, NO, NZ, PL, PT, RO, RU, SD, SE, SG, SI, SK, SL, TJ, TM, TR, TT, UA, UG, US, UZ, VN, YU, ZW

Claims (14)

[Claims] 1. An electric machine comprising air introduction means arranged and arranged to direct a flow of air over the outside of the machine. 2. The electric machine according to claim 1, wherein the air introduction means covers at least a part of the outside of the machine. 3. The electric machine according to claim 2, wherein the air introduction means comprises a protective hood which is an outer part of the fan housing or is fixed to the fan housing. 4. The electric machine according to claim 3, wherein the protective hood extends over at least a portion of the exterior of the machine from a fan housing located at one end of the machine, wherein a gap is provided between the protective hood and the exterior. Provided, electromechanical. 5. An electric machine according to claim 3 or 4, wherein each of the electric machines comprises an AC motor having a stator and a rotor having a laminate, and a protective hood holding the stator laminate together with the stator laminate. Or an electric machine secured to a bracket at one end of the motor. 6. The electric machine according to claim 3, wherein the air introducing means comprises an air deflector disposed in the fan housing and having a frusto-conical or cylindrical shape. machine. 7. The electric machine according to claim 6, wherein the baffle is integrally formed in or attached to the housing. 8. The electric machine according to claim 1, wherein the air introduction means sends air through at least one hole of the machine. 9. An electric machine according to claim 1, wherein the air introduction means is fixed to the outside of the machine, formed on the outside of the machine, or arranged at a position immediately adjacent to the outside of the machine. An electrical machine comprising at least one protrusion. 10. The electric machine according to claim 9, wherein the protrusions can define one or more passages through which air flows. 11. An electric machine according to claim 1, wherein:
An electric machine comprising: a stator having a winding; and a protection hood for the stator winding at at least one end thereof. 12. The electric machine according to claim 11, wherein the protective hood is connected to a bracket at one end, the pressure plate or the stator itself. 13. An electric machine according to claim 1, wherein:
An electric machine comprising two brackets and a terminal board completely enclosed within one of the brackets. 14. An electric machine substantially as described and illustrated with reference to the accompanying drawings.