EP1872461A1

EP1872461A1 - Electric motor

Info

Publication number: EP1872461A1
Application number: EP06724073A
Authority: EP
Inventors: Sven Tesch
Original assignee: SEW Eurodrive GmbH and Co KG
Current assignee: SEW Eurodrive GmbH and Co KG
Priority date: 2005-04-12
Filing date: 2006-04-06
Publication date: 2008-01-02
Also published as: EP3301790B1; EP3301790A2; PL3301790T3; CN101160704A; HUE046700T2; WO2006108550A1; EP3301790A3

Abstract

The invention relates to an electric motor with a stator that comprises cooling fins and fastening elements, additional components, especially rating plate, mounting plate or the like being detachably linkable with the stator by means of the fastening elements. The invention is characterized in that the fastening means are configured as enlargements of the cooling fins.

Description

electric motor

Description:

The invention relates to an electric motor.

Motors with fans for self-ventilation and cooling fins on the stator housing are known.

From EP 0 917 276 A1 a stator housing for electric motors is known in which a terminal box 10 engages with a projecting from its through hole 20 in the bottom 14 nozzle 24 through a through hole 42 in the stator housing 4. In this case, the passage opening extends transversely to the cooling fins 40 over a region of a plurality of cooling fins (FIGS. 6 and 17). To attach the terminals box sleeve-shaped formations 46 are provided, which are arranged in interruptions of the cooling fins and which engages in the extension of the cooling fins formed by the axially extending intermediate spaces. The through-hole and the sleeve-like formations are provided at the top and at the sides of the stator housing, so that a terminal box 10 can be selectively attached to one or more of the three attachment locations on the stator housing (Sp. 4, Z. 4-11).

The invention has the object of developing an electric motor with improved cooling.

According to the invention, the object is achieved in the electric motor according to the features indicated in claim 1.

Important features of the invention in the electric motor are that the latter comprises a stator with cooling fins and fastening elements,

wherein a foot plate is releasably connectable by means of the fastening elements with the stator,

wherein the fastening means are designed as streamlined thickening of cooling fins, wherein the fastening elements are arranged on the stator such that the foot plate can be fastened in at least two, in particular three, orientations on the stator, in particular in at least two different directions of the normal of the foot plate.

Here, under streamlined a profile shape of the cooling fins with thickening understood, with the profile shape results by cutting the cooling fins with a coaxial mathematical-imaginary cylinder. The profile shape is streamlined, so that a low flow resistance for the cooling air flow is present.

The advantage here is that air ducts can be formed by the cooling fins, in which air, in particular starting from a motor fan, the stator housing flows along. Further, the foot plate is variably orientable relative to the terminal box and attachable by the foot plate is mounted on one of the three sides. The terminal box is thus firmly predictable on a fourth page. This advantageously avoids that three

Through holes, so in each case a through hole on each side, obstruct the flow of air along the cooling fins and in particular steer radially away from the stator housing. The streamlined shape of the fasteners advantageously causes the cooling air during normal operation of a motor fan, ie at flow velocities of 2 to 7 m / s in the air channels laminar, so with Reynolds number between 1200 and 4000 at a clearance of the ribs with almond-shaped thickening of each other from 6 to 15 mm, flows. The clear distance between the ribs with almond-shaped thickenings for this purpose represents a characteristic, the geometry descriptive length. The axial length of the usable motors is between 0.1 m and 1 m.

In further advantageous embodiments, flow velocities of 1 to 10 m / s in the air channels are also useful. Reynolds numbers between 1000 and 5000 are also advantageous. The distance of the ribs is also advantageous from 4 to 30 mm selectable.

At other flow rates, the structural dimensions of the stator housing with ribs to achieve a Reynolds number in the range as indicated above to choose accordingly. For larger flow velocities, the characteristic length should be smaller so that the product of both sizes remains constant, and vice versa. Instead of air, a coolant, for example water, which can flow in the air ducts, can generally also be provided. In this case, in particular, the flow velocity and the characteristic length are to be adjusted such that the Reynolds number is in the range indicated above.

In a further advantageous embodiment, the cooling fins form air ducts in which air, in particular from one end face of the stator housing to the other, in particular laminar, flows.

Surprisingly, the laminar flow conditions have the particularly advantageous effect that the air flow passes over the entire stator length and is not guided away from the air ducts and thus away from the stator housing by turbulence. Although the turbulence locally improves the cooling behavior, however, lead to parts of the stator housing are not swept by the air flow. Thus, surprisingly, the cooling performance is reduced by the occurrence of turbulence.

In a further advantageous embodiment, connecting means, such as screws, rivets or clip means, for connecting the base plate with the fastening means are designed such that they do not change the streamlined shape of the cooling fins in the mounted position. In particular, blind holes or recesses are provided in the fastening means, which extend in the imaginary plane through the head and foot of the cooling fins and into which the connecting means are insertable.

The advantage here is that no additional, the air flow in the air ducts in its flow obstructing parts are introduced by the connection of the foot plate with the fasteners. This improves the cooling of the engine.

In a further advantageous embodiment, additional streamlined fastening means are provided in the cooling fins, in particular for fastening type and / or rating plates and / or electronic assemblies.

The advantage here is that additional functions and / or additional electronic functions on the stator housing are easy and safe attachable without disturbing the laminar flow in the air channels. In a further advantageous embodiment, the arrangement of the fastening elements has a two-, four- or multiple rotational symmetry.

The advantage here is that the foot plate and / or nameplates and / or electronic modules can be mounted on one side in different orientations.

Important features in the cooling device for an electric motor according to claim 6 are that three cooling fins, in particular in the circumferential direction three successive, are included, of which a first and a second to form a first air duct and the second and third to form a second adjacent air duct are provided, wherein the channels extend in the axial direction, and wherein the central, ie the second cooling fin fastening means, wherein the side surfaces, so the axially extending flank surfaces, the cooling fins to avoid or reduce turbulence in the respective air duct are streamlined, in particular continuously differentiable.

The advantage here is that an air flow between the cooling fins is laminar feasible. Particularly advantageous turbulences are avoided by the continuously differentiable design of the cooling fin side surfaces, which would cause a distraction of the air flow away from the stator and thus a reduction of the cooling capacity. A further advantage is that a terminal box and / or housing for electronic assemblies and / or foot plates can be fastened to the stator, wherein these do not constitute an additional flow resistance in a fixed position for the air flow.

In a further advantageous embodiment, the air ducts as A- and B-side, so the end faces of the stator, connecting, linear, in particular paraUel extending, channels are formed, which are limited in particular by the cooling ribs transversely to the axial direction. In particular, it is advantageous in the air channel formed by the three cooling fins laminar air from the B-side to the A-side, or vice versa, durchleitbar.

Here, B-side is understood to mean a side of the electric motor on or on which a fan or a flow source for the coolant is arranged. By A side is meant a side of the electric motor to which the coolant flows from the B side. A and B side of an electric motor are preferably by the location of end shields described, which are connected to the opposite end faces of the stator housing.

The advantage here is that the air flow for cooling over the entire length of the stator.

In a further advantageous embodiment, no flow resistance increasing objects or obstacles are provided in the air ducts, in particular after attachment of devices to the fastening means, in particular on the fastening means blind holes are provided which extend in the imaginary plane through the head and foot of the cooling fins and in the connecting means for fixing are insertable.

The advantage here is that devices can be attached to the fastening means, without the air flow is hindered in the air channels.

Important features of the invention in the cooling device for an electric motor according to claim 10 are that axially extending straight fins and axially extending cooling fins are included with thickening, wherein the thickenings of the cooling fins with thickening fastening means comprise, the lateral surfaces of the straight fins at each location a Tangentialvektor define, which is parallel to the motor axis, and the side surfaces of the cooling fins are designed streamlined, in particular continuously differentiable.

The continuous differentiable design of the side surfaces of the cooling fins, which is designed as a mathematical ideal within technical tolerances, advantageously causes kinks, edges and / or steps in the side surfaces of the cooling fins are avoided. However, such kinks, edges and / or steps are known as the cause of turbulence in the air flow. The continuously differentiable design thus advantageously avoids the occurrence of such turbulence, leading to laminar

Flow conditions between the cooling fins. Thus, a deflection of the air flow away from the stator is advantageously avoided.

In a further advantageous embodiment, the cooling fins extend over the length of the stator housing. In a further advantageous embodiment, the Tangenttalvektor forms an angle of magnitude not more than 40 °, preferably less than 30 ° to the profile shape of the cooling fins with thickening with the motor axis.

As a result, geometric shapes of the cooling fins are advantageously avoided, which favor the formation of turbulence in the air flow.

In a further advantageous embodiment, each cooling fin with thickening of two straight cooling fins is adjacent.

The advantage here is that the thickening does not protrude from two adjacent cooling fins in the common space and thus does not distract the air flow and swirl.

In a further advantageous embodiment, the axial spatial extent of the fastening means is more than twice as large as the transverse extent of the fastening means.

The advantage here is that the fastening means have a particularly streamlined shape and thus affect the air flow between the cooling fins as little as possible.

In a further advantageous embodiment, the transverse extent of the fastening means exceeds the clear distance to at least one adjacent cooling rib.

The advantage here is that the fastening means provide a large attachment surface for devices to be fastened, in particular thus a foot plate is stably attachable to the stator housing.

Important feature of the invention in the electric motor with stator are that cooling fins and fasteners are included, wherein other components, in particular rating plate, foot plate or the like, are releasably connectable by means of the fastening elements with the stator, and wherein the fastening means are designed as thickening of cooling fins, wherein in the air channels formed by the cooling fins no further obstacles, ie flow resistance-increasing objects and / or formations, are provided, in particular that the air flow in the air ducts flows laminarly in the axial direction and does not lift off the cooling fins or out of the spatial area between the cooling fins.

The advantage here is that only slight thickening in the cooling fins are sufficient to accommodate the fasteners can. Thus, even screws can be screwed into the cooling fins and the heat can be delivered to the bolted further component. In addition, the air duct covered by the further component between two adjacent cooling fins is kept free by the thickening is made sufficiently small. In particular, thickenings are shaped such that the cooling air flow along the cooling fins is unhindered or is only slightly hindered by the thickening. The advantage here is that the cooling, ie heat dissipation to the ambient air is improved and the performance of the engine is increased, in particular the maximum permissible power.

In an advantageous embodiment, the thickenings in the direction of the cooling rib extend approximately almond-shaped or streamlined and are spatially less extensible in the direction of the normal of the cooling rib than the distance to the next adjacent cooling rib. The advantage here is that the cooling air flow runs as laminar as possible, so as little as possible turbulence. Small turbulences, which run transversely to the flow direction as a small self-contained vortex, are already introduced by the fan and are conducive to cooling. The thickening can be carried out in such a way that the cooling air flow in the direction of the cooling rib is not stirred up and does not lift off, ie does not leave the space region between the cooling ribs that is decisive for the cooling. The almond-shaped shape of the surface in the fin direction is continuously differentiable.

In an advantageous embodiment, at least some of the fastening means lie in one plane. The advantage here is that just executed, other components are screwed.

In an advantageous embodiment, at least four of the fastening means lie in one plane. The advantage here is that a foot plate is releasably connectable and the motor is stably attachable to such a mounting plate. In an advantageous embodiment, the thickening in the direction of the normal of the cooling fin are spatially less extensive than half the distance to the next adjacent cooling fin to reduce the influence on the cooling air flow. The advantage here is that the cooling air flow flows within the ribs.

In an advantageous embodiment, the thickenings include blind bores or centering aids, which are formed, for example, as conical recesses. The advantage here is that simple and inexpensive fasteners are providable.

In an advantageous embodiment are at least four first of the fastening means in a first plane and at least four second of the fastening means in a second plane, which is arranged perpendicular to the first plane. The advantage here is that the engine can be mounted in different orientations.

In an advantageous embodiment, two fastening means for the detachable connection with a Leistungsschiid and four other fastening means for the detachable connection with a base plate, ie mounting plate, are provided, in particular in the region of the first plane. The advantage here is that the nameplate or the foot plate are selectively connectable.

Further advantages emerge from the subclaims.

LIST OF REFERENCE NUMBERS

1 flange

2 cooling rib

5 3 almond-shaped thickening

4 fan cover

5 terminal box base

6 Terminal box top 20 cams

10 30 Cable gland 31 Stack edge

40 rectifier module as an option

41 fixing screws for option

42 clipboard

15 43 Protective earth connection device 80 Drill hole in cam

100 increase

101 well

20

The invention will now be explained in more detail with reference to figures:

In FIGS. 1 to 6, an electric motor according to the invention is shown in different views. The lower part of the associated terminal box is shown in Figures 7 and 8 in different views.

The motor is designed as an electric motor and has a flange 1, with which a further device to be driven, such as gear or mixer, can be connected.

At its stator housing, the engine has cooling fins 2, which partially have almond-shaped thickenings 3. The fan cover 4 is provided on the opposite side of the flange 1. The terminal box, which can also be labeled as a terminal box, is composed of a terminal box lower part 5 and a connection box upper part 6 that can be connected to it in a detachable manner as a lid. The terminal box lower part 5 has, on its outer side facing the stator housing of the motor, cams 20 which constitute material accumulations for introducing a bore.

Since the parts of the engine, but in particular the housing-forming parts of the engine are designed to save as much material, the introduction of a bore in the housing is not easy and stable possible. Therefore, the cams 20 provide material thickening, in which the holes 80 from the interior of the terminal box base are introduced. The shape of the cams is shark-fin-like. The cams are directed towards the engine at the junction box bottom. Without an oblique side, the strength would not be enough. The shark fin-like expression allows for slightly more material consumption than for the bore 80 would be necessary high strength. Another surface that would be inclined would increase the material consumption further, but would not have a correspondingly large strength-increasing effect. The borehole 80 is designed as a pre-cast blind hole. Only material around the wellbore 80 is used so that the minimal amount of material is consumed, with only one sloped side provided for increasing strength with low material consumption.

The terminal box base 5 includes in its housing wall cable glands 30 for passing cables. The protective conductor included therein is connected to the protective conductor connecting device 43. The rectifier module 40 is fastened as an option with the fastening screws 41 in the connection box lower part 5.

The terminal board 42 serves at least to connect the power supply lines routed through the cable glands 30 to the winding wires of the stator.

The fan cover 4 has on its circumference in the circumferential direction alternately elevations 100 and recesses 101, so wavy indentations in the circumferential direction in the intake of the fan cover. That way are

Noise emissions reduced and in addition the rigidity of the fan cover 4 is increased. The fan cover 4 additionally has a peripheral stacking edge 31. By means of this stacking edge 31, the hoods 4 are space-saving stackable in the warehouse. The stack edge additionally has a stiffening effect on the fan cover 4.

The almond-shaped thickenings 3 are designed as a thickening of the cooling fins on the stator housing for the attachment of the Typenschiides, ie rating plate, or for example on another side for the attachment of a base plate on which the engine is mounted. The almond-shaped thickenings 3 are arranged for this purpose within a plane. In particular, four of these each belong together. The almond shape is designed such that they impede the flow of cooling air between two adjacent cooling fins as little as possible. For this they are about streamlined or almond-shaped running along the cooling fins. So the cooling fins are only slightly thickened in these areas. Advantageously, therefore, the engine is better cooled than in the prior art. Because there is no thickening that obstructs the flow of air between two cooling fins along the cooling fins. None of the thickenings even connects two adjacent cooling fins. Instead of introducing a blind hole, it is also advantageous to initially introduce only conical recesses as centering in the production. Only if then during the assembly of the engine really a hole should be provided, such is introduced. But then the drilling tool is simply centered and the location of the hole already pre-marked.

The holes are executed in further embodiments of the invention as blind holes. Those thickenings which can be used for the attachment of the base plate, have in further embodiments according to the invention a conical recess in the region of the borehole as a centering when screwing the mounting screws.

Instead of the rectifier module 40 are further inventive

Embodiments also other electronic circuits, such as motor starters or soft starters or converters and control circuits, or connecting devices, such as terminal strips or fixtures, such as mounting rails or the like, connectable.

Claims

claims:

1. Electric motor with stator comprising cooling fins and fastening elements,

characterized in that

the fastening means are designed as streamlined thickenings of cooling ribs,

wherein the fastening elements are arranged on the stator such that the foot plate can be fastened in at least two, in particular three, orientations on the stator, in particular in at least two different directions of the normal of the foot plate.

2. Electric motor according to at least one of the preceding claims, characterized in that the cooling fins form air channels in which air in particular laminar, in particular from one end face of the stator to the other, flows.

3. Electric motor according to at least one of the preceding claims, characterized in that the connecting means for connecting the base plate with the fastening means in the mounted position do not change the streamlined shape of the cooling fins, in particular that in the fastening means blind holes are provided, in the imaginary plane through the head and Base of the cooling fins run and in which the connecting means are insertable.

4. Electric motor according to at least one of the preceding claims, characterized in that additional streamlined fastening means are provided in the cooling fins, in particular for attachment of type and / or rating plates and / or electronic assemblies.

5. Electric motor according to at least one of the preceding claims, characterized in that the arrangement of the fastening elements has a two, four or multiple rotational symmetry.

6. Cooling device for an electric motor,

comprising three cooling ribs, in particular three successive ones in the circumferential direction,

of which a first and a second are provided for forming a first air channel and the second and third for forming a second adjacent air channel,

the channels being in the axial direction,

characterized in that

the middle, that is the second, cooling fin comprises fixing means,

wherein the side surfaces of the cooling fins are designed to be streamlined in order to avoid or reduce turbulence in the respective air duct,

especially continuously differentiable.

7. Cooling device according to at least one of the preceding claims, characterized in that the air ducts as A- and B-side, so the end faces of the stator housing connecting, linear, in particular parallel, channels are formed, in particular of the cooling ribs transversely to the axial direction be limited.

8. Cooling device according to at least one of the preceding claims, characterized in that no flow resistance increasing objects or obstacles are provided in the air ducts, in particular after attachment of devices to the fastening means, in particular on the fastening means blind holes are provided which in the imaginary plane extend through the head and foot of the cooling fins and are insertable into the connecting means for fastening.

9. Cooling device according to at least one of the preceding claims, characterized in that in the air channel formed by the three cooling fins laminar from the B-side to the A-side, or vice versa, is durchleitbar.

10. Cooling device for an electric motor,

full

axially extending straight cooling fins,

and axially extending cooling fins with thickening,

characterized in that

include the thickenings of the cooling fins with thickening fastening means,

the lateral surfaces of the straight cooling fins define at each point a tangential vector which is parallel to the motor axis,

and the side surfaces of the cooling fins are carried out streamlined, in particular continuously differentiable.

11. Cooling device according to at least one of the preceding claims, characterized in that the cooling ribs extend over the length of the stator housing.

12. Cooling device according to at least one of the preceding claims, characterized in that the tangential vector to the profile of the cooling fins with thickening with the motor axis an angle of at most 40 °, in particular at most 30 °, forms.

13. Cooling device according to at least one of the preceding claims, characterized in that each cooling fin is adjacent to thickening of two straight cooling fins.

14. Cooling device according to at least one of the preceding claims, characterized in that the axial spatial extent of the fastening means is more than twice as large as the transverse extent of the fastening means.

15. Cooling device according to at least one of the preceding claims, characterized in that the transverse extent of the fastening means exceeds the clearance to at least one adjacent cooling fin in terms of size.

16. electric motor with stator comprising cooling fins and fixing elements,

wherein further components, in particular rating plate, foot plate or the like, are detachably connectable to the stator by means of the fastening elements,

characterized in that

the fastening means are designed as thickenings of cooling fins

wherein in the air channels formed by the cooling fins no further obstacles, ie flow resistance increasing objects and / or formations, are provided, in particular that the air flow in the air ducts laminar flows in the axial direction and does not lift off the cooling fins or from the space between the cooling fins.

17. Electric motor according to at least one of the preceding claims, characterized in that the thickenings in the direction of the cooling rib approximately almond-shaped or streamlined and are spatially less extensible in the direction of the normal of the cooling fin than the distance to the next adjacent cooling rib.

18. Electric motor according to at least one of the preceding claims, characterized in that at least some, in particular at least four, of the fastening means lie in one plane

19. Electric motor according to at least one of the preceding claims, characterized in that the thickening in the direction of the normal of the cooling fin are spatially less extensive than half the distance to the next adjacent cooling fin to reduce the negative influence on the cooling air flow.

20. Electric motor according to at least one of the preceding claims, characterized in that the thickenings include blind holes and / or centering aids

21. Electric motor according to at least one of the preceding claims, characterized in that at least four first of the fastening means lie in a first plane and at least four second of the fastening means lie in a second plane, which is arranged perpendicular to the first plane.

22. Electric motor according to at least one of the preceding claims, characterized in that two fastening means, in particular blind hole, for releasable connection with a nameplate and four other fastening means, in particular with centering for a tool, for releasable connection to a base plate, so mounting plate , are provided, in particular in the area of the first level.