DE102011104892A1 - Machine tool has cooling duct that is connected with motor-receiving element molded on outside of shell surface of stator - Google Patents

Abstract

The machine tool has a motor unit that is provided with a stator (6) and a rotor shaft. The rotor shaft is connected with rotor unit. A cooling duct (2) is connected with the motor unit for cooling motor unit. The outside of the shell surface of the stator is molded with a motor receiving element (1) for receiving the motor unit. The cooling duct is connected with a motor-receiving element. An independent claim is included for method for manufacturing machine tool.

Description

The invention relates to a machine tool with an electric motor unit such as a multi-axis turning head, a motor spindle, a turntable or the like according to the preamble of claim 1 and a corresponding manufacturing method according to the preamble of claim 8.

State of the art

Machine tools are increasingly using directly driven components. Since these directly driven components are always lossy, that is, there are always electrical and mechanical losses between the supplied electrical energy and the mechanical energy that can be used for machining, which are usually several kilowatts, such systems are always cooled.

In most cases, a liquid cooling is used, the supplied cooling liquid are passed through suitable channels generally around the main loss sources such as the electric motor, so that as much heat energy can be transmitted on the largest possible surface.

The design of the channels can take place in the stator housing and by a so-called closed cooling circuit directly on the motor, for example on the motor spindle, the turntable or the like, or on / in the motor housing. This means that the stator of the electric motor is z. B. pressed into a sleeve whose outer surface is designed with channels and these open channels are pushed by the insertion of the stator including the stator sleeve in a tubular housing which is provided on both faces with sealing rings, whereby the channels are closed.

On the other hand, a design variant in machine tool manufacturing is the manufacture of the motor spindle housing with open cooling grooves, wherein the spindle receptacle of the machine tool forms an outer wall of the cooling channels. Again, appropriate seals for sealing the cooling channels can be provided.

A disadvantage of both designs, however, is that they are relatively expensive. In addition, especially in the case of the open cooling channels is particularly problematic that the casting material of the spindle receptacle in some cases does not have the necessary tightness. These leaks may cause coolant to possibly penetrate internal structures of the machine tool.

Purpose and advantages of the invention

The object of the invention is in contrast, a machine tool with an electric motor unit such as a multi-axis turret, a motor spindle, a turntable or the like and with at least one of a cooling fluid, in particular by a cooling liquid, through-flow cooling channel having cooling device for cooling the motor unit, wherein at least partially outside of the lateral surface of the stator unit or of the motor housing, a cast motor receiving element for receiving the motor unit is arranged, and to propose a corresponding manufacturing method, wherein the cooling device is manufactured without great design effort and high reliability and reliability with respect to the tightness of the cooling device is realized.

This object is achieved on the basis of a machine tool and a method of the aforementioned type by the features of claims 1 and 8. The measures mentioned in the dependent claims advantageous embodiments and developments of the invention are possible.

Accordingly, a machine tool according to the invention is characterized in that the motor receiving element comprises at least one cast-in insert element for forming the cooling channel, wherein the insert element is formed as a tubular element.

With the aid of such an advantageous cast-in pipe element for forming the cooling channel within the motor mount or the motor receiving element, a particularly cost-effective and at the same time reliable cooling of the electric motor unit can be realized. On the one hand, the use of a tube element ensures the tightness of the cooling channel or section of the cooling circuit in the region of the motor unit of the machine tool. On the other hand, a cost-effective production of the motor unit or its cooling is realized by pouring the cooling channel into the motor receiving element.

Thus, advantageously, a motor unit can be produced without cooling and mounted or operated in the motor mount or within the motor mount element of the machine tool. An electric motor unit according to the invention without cooling ensures that both the constructive and the economic effort in the manufacture of the motor unit significantly reduced becomes. Optionally, a stator housing is formed as a substantially smooth hollow cylinder tube / sleeve, which is inserted or mounted in an advantageous manner in a substantially cylindrical recess of the motor receiving element or the motor mount.

Preferably, there is almost no radial gap or only a minimal or comparatively small / thin gap between the stator housing of the motor unit according to the invention and the motor mount or the motor mount element. Possibly, in the installed state of the motor unit, a gap existing due to manufacturing tolerances is advantageously provided by means of heat paste or a comparatively good heat-conducting material for bridging the gap or filling the gap. By the smallest possible gap or by the elimination of the air gap between the stator housing and the motor receiving element, the heat conduction or heat radiation of the stator is significantly improved with respect to the motor receiving element and thus to the cast-in cooling channel, so that the cooling efficiency is increased accordingly.

Advantageously, the motor receiving element has at least two connections for the supply and removal of the cooling fluid, in particular the cooling fluid. As a result, the pipe element according to the invention can be connected in an advantageous manner to a cooling circuit.

In an advantageous variant of the invention, the insert element is designed as a round tube. Round tubes have an advantageous flow through and are inexpensive to produce and already commercially available in a variety of variants, so that in this way a particularly cost-effective implementation of the invention is possible.

Preferably, the insert element is at least partially formed as a helix. With an insert element embodied as a helix, it is achieved that an advantageous sheathing of the motor unit or the stator unit can be provided, so that the heat loss of the motor unit is dissipated by the cooling according to the invention in a particularly advantageous manner.

In a particular embodiment of the invention, the insert element is arranged on an inner circumferential surface of the motor receiving element. Preferably, a (smallest possible) distance between the insert element or the tubular element according to the invention and the inner circumferential surface of the motor receiving element is provided. Thus, especially with regard to the heat conduction from the motor unit to / in the cooling channel of advantage, this distance advantageously small as possible. As a result, the cooling is arranged as close as possible to the heat generation in the stator or the stator unit, which has an advantageous effect for the cooling.

It is also conceivable that quite a part / portion of the lateral surface of the tubular element at least partially forms the inner circumferential surface of the motor receiving element. This means that in this particular variant, the tube element is not spaced from the inner circumferential surface of the motor receiving element, but is arranged directly on the stator housing or the stator unit. In this case, especially rectangular pipe elements can be as a cast-in insert element of particular advantage.

For example, the motor receiving element according to the invention is essentially made of aluminum or cast aluminum, in particular aluminum alloys. By using comparatively low melting point materials such as corresponding metals or the like for the motor receiving element, it can be achieved that a relatively inexpensive or commercially available material can be used for the cast-in insert element with a higher melting point. For example, the insert member may be formed as a copper pipe or the like. Preferably, the insert element consists essentially of steel. Steel has the advantage that it can be formed economically as a tubular element and at the same time has a comparatively high melting temperature of about 1500 ° C., so that this is itself during remelting with low-melting metals such as cast aluminum or cast iron such as gray cast iron does not melt and is therefore not affected.

Advantageously, in the manufacturing method for a machine tool according to the invention, in particular in the manufacture of the motor mounting element according to the invention, a casting model / mold is used, which is provided for the production of the cast motor receiving element. Before the casting, a pipe element according to the invention is inserted or introduced here. In this case, an advantageous and comparatively thin-walled tubular element can be provided, which is arranged as close as possible to the inner lateral surface of the model or of the engine intake element to be cast. The inner circumferential surface of the motor receiving element is provided for receiving in the machine tool according to the invention the electric motor unit, such as a motor spindle or the like.

Preferably, the pipe element is at least partially wound in coils around the inner surface of the model or to be poured Motor receiving element looped or bent. After the pipe element has been laid in an advantageous manner, preferably a liquid metal is poured into the model mold. After cooling and the advantageous molding of the cast part or the cast motor receiving element, the cooling spiral formed by the cast-in tubular element is available for dissipating the heat energy or the power loss of the motor unit.

In general, the motor receiving element according to the invention can be installed or fixed in a support structure of the machine tool in an advantageous manner. According to the invention, a highly efficient cooling channel is produced with relatively little design effort and using metal pipes, which also has no susceptibility to any porosity of the casting material or impairments of seals as in the prior art. Accordingly, according to the invention, an economically favorable and reliable cooling for electric motor units of machine tools can be realized.

embodiment

An embodiment of the invention is illustrated in the drawing and will be explained in more detail with reference to FIGS.

In detail shows:

1 a schematic perspective view of a motor receiving element according to the invention,

2 a schematic plan view of the motor receiving element according to 1 and

3 a schematic section through the motor receiving element according to the invention 1 ,

In 1 is schematically a motor receiving element 1 represented, in which a cooling channel 2 (shown in dashed lines) is poured. According to the invention, it is the cooling channel 2 around a cast round tube, which is preferably made of steel. Also, in this variant, the cooling channel 2 essentially in the form of a helix in the motor mount or the motor receiving element 1 cast.

In the manufacture of the motor receiving element of the cooling channel 2 or the pipe 2 placed in a mold and as close as possible to an inner lateral surface 3 poured in (cf. 3 ).

The cooling channel 2 has a lead 4 and a return 5 for a cooling liquid or a (closed) cooling circuit. Without further representation, the flow 4 and the return 5 connected to a cooling system or the cooling circuit of a machine tool, not shown, so that in operation, the motor mount or the motor receiving element 1 cooled and waste heat of a motor unit is dissipated.

In the figures, only one stator unit 6 the motor unit according to the invention shown. The stator unit 6 includes, among other induction coils 7 or coil windings via electrical cables 8th be supplied with electrical energy to drive the motor unit.

In addition, the stator unit includes 6 stator laminations 9 , In addition, an insulating encapsulation is advantageously 10 provided, which the induction coils 7 as well as the Pohl plates 9 essentially encloses. As a result, inter alia, an electrical insulation of the induction coils 7 as well as an advantageous, large-area contact surface with the motor mount or the motor receiving element 1 or realized a thin-walled, possibly metallic stator housing, not shown.

Especially in 3 the schematic structure of the example of a directly driven turntable or torque motor for a machine tool according to the invention is particularly clear. This shows how the individual turns of the cooling channel 2 around the stator 6 Loop around the circumference, so that during operation, an advantageous cooling in the stator unit 6 generated waste heat is realized.

In the motor mount or the motor receiving element 1 According to the invention, it is preferably a cast metal element, in particular a cast iron element, in which the (noble) steel existing cooling channel 2 is integrated. Due to the different melting temperatures of, for example, gray cast iron and steel, the steel pipe or the cooling channel 2 be placed in an advantageous manner in a corresponding mold and cast around the liquid gray cast iron or metal casting. This results in a very good heat transfer between the cooling channel 2 or the steel tube and the casting material of the motor receiving element 1 realized.

By using the tube as a cooling channel 2 In addition, this ensures that it is absolutely leakproof for a coolant, resulting in an impairment of operation due to leakage of the cooling channel 2 safely prevented. Even if during the casting process of the motor receiving element 1 Porosities, cracks or similar impairments should arise, is the cooling channel 2 or the tube element according to the invention for the cooling liquid absolutely tight.

By the arrangement of the cooling channel 2 as close to the inner surface 3 the motor mount is achieved that the cooling or heat dissipation is extremely efficient feasible.

In addition, by using a steel tube as a cooling channel 2 an advantageous and above all cost-effective production of the cast motor receiving element 1 realizable.

LIST OF REFERENCE NUMBERS

1

Motor receiving element

2

cooling channel

3

lateral surface

4

leader

5

returns

6

stator lamination

7

induction coil

8th

electric wire

9

Pohl sheet

10

Isolationsverguss

Claims (9)

Machine tool with an electric motor unit such as a multi-axis turret, a motor spindle, a turntable or the like, wherein the motor unit at least one stator unit ( 6 ) and a rotor unit having at least one rotor shaft which is rotatable about an axis of rotation, wherein a cooling channel through which at least one of a cooling fluid, in particular a cooling fluid, can flow ( 2 ) having cooling device ( 2 ) is provided for cooling the motor unit, wherein at least partially outside of the lateral surface ( 3 ) of the stator unit ( 6 ) a cast motor receiving element ( 1 ) is arranged for receiving the motor unit, characterized in that the motor receiving element ( 1 ) at least one cast-in insert element ( 2 ) for the formation of the cooling channel ( 2 ), wherein the insert element ( 2 ) as a tubular element ( 2 ) is formed. Machine tool according to claim 1, characterized in that the motor receiving element ( 1 ) at least two ports ( 4 . 5 ) for supplying and discharging the cooling fluid. Machine tool according to one of the preceding claims, characterized in that the insert element ( 2 ) as round tube ( 2 ) is trained. Machine tool according to one of the preceding claims, characterized in that the insert element ( 2 ) Is at least partially designed as a helix. Machine tool according to one of the preceding claims, characterized in that the insert element ( 2 ) on an inner circumferential surface ( 3 ) of the motor receiving element ( 1 ) is arranged. Machine tool according to one of the preceding claims, characterized in that the motor receiving element ( 1 ) consists essentially of cast steel. Machine tool according to one of the preceding claims, characterized in that the insert element ( 2 ) consists essentially of steel. Method for producing a machine tool with an electric motor unit such as a multi-axis rotary head, a motor spindle, a turntable or the like, wherein the motor unit comprises at least one stator unit ( 6 ) and a rotor unit having at least one rotor shaft rotatable about an axis of rotation, wherein a cooling channel through which at least one of a cooling fluid, in particular a cooling fluid, can flow ( 2 ) having cooling device ( 2 ) is used for cooling the motor unit, wherein at least partially outside of the lateral surface ( 3 ) of the stator unit ( 6 ) a cast motor receiving element ( 1 ) is arranged for receiving the motor unit, characterized in that during casting of the motor receiving element ( 1 ) at least one insert element ( 2 ) is used, wherein the insert element ( 2 ) as a tubular element ( 2 ) for the formation of the cooling channel ( 2 ) is formed. Method according to Claim 8 and for producing a machine tool according to one of the preceding claims.

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