DE8712149U1 - Impregnation machine for impregnating electrical machine parts - Google Patents

Description

10 35-

5904 IP-DE

Mr. Fritz Bäuerle 7208 Spaichingen

Tmnränni prmncnhi no :711m T mrrnan &eegr; 4 &ogr;&tgr;»&ogr;&eegr; , j, _r _ _-,.._ ~-„..

of electrical machine parts

The invention relates to an impregnation machine for - p. impregnating machine parts intended for electrical machines ,

It is known to impregnate slotted stators or rotors with wire windings with flowable, hardenable _epoxy resin or polyester resin by trickle impregnation. To do this, the machine part in question (rotor or stator) is first heated to temperatures of approx. 75 to 80 ⁰ C. This machine part is then slowly rotated around its longitudinal axis with the longitudinal axis inclined at an angle to the horizontal (the angle of inclination being infinitely variable depending on the size of the machine part and the winding structure) and, if the

«•««4»

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&rgr; drip temperature of approx. 75 to 8Ö°C is

' so-called trickling nozzles drip the synthetic resin simultaneously at several points onto the winding head of the machine part, which is positioned higher than the other winding head due to the tilting position. Several trickling nozzles are used, which can be adjusted independently of one another in order to bring them into such positions that the synthetic resin is spread along the winding head by capillary action and gravity.

of the entire winding through the winding heads and the slots. It should also penetrate into the Ip slots between the slot isclations separating the coil sides located there from the slot walls and the slot walls. This trickling process is carried out in this known trickling impregnation process for a predetermined period of time, which is chosen so that both winding heads and the coil sides located in the slots are filled with the synthetic resin as much as possible. After this dripping of the synthetic resin has been completed, the machine part is swiveled into a horizontal position and hardened with further rotation and temperature increase to approx. 135 to 160 C (depending on the type of synthetic resin). This trickling impregnation process has the advantage that the synthetic resin introduced is

. machine part even after it has been applied to the

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remains on the winding parts and does not drip off again due to the increase in temperature required for hardening. This trickle impregnation process is used in particular for highly stressed rotors, as it provides better hardening of the winding parts in the laminated cores and higher

2Q centrifugal strength can be achieved. However, the setting of the trickling nozzles is critical, so that the achievement of relatively well-strengthened machine parts and relatively good centrifugal strength depends largely on the operator's ability to adjust the trickling nozzles

J5 in each case depends on the setting. In this previously known process, these drip nozzles must be set to different points on the relevant rotating winding head, and impregnating agent must be dripped onto the outside, the slanted front side and the inside of the higher winding head. Even if this setting was quite good for one machine part, it is still not suitable for the

&ogr;= Serial impregnation of machine parts, because the windings are different for each machine part and the conditions for the migration of the impregnating agent in the winding and the slots are different for each machine part. This well-known

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5904 IP-DE - &bgr; -

In series production, trickle impregnation leads to significant, uncontrollable and not recognizable quality fluctuations in the machine parts impregnated using this method without causing destruction of the finished machine part, which is extremely undesirable because when using machine parts impregnated using this trickle impregnation method and manufactured in series, they must be given the lowest quality level.

It is also known to completely immerse stators in a synthetic resin impregnation bath for their impregnation - which is possible because they have no collectors - and to quickly rotate them around their longitudinal axes after removing them in order to throw away the excess impregnating agent. This

2Ö process is called dip rolling.

However, it was found that this dip rolling process did not achieve the desired leveling and improvement in quality, apart from the fact that it was not suitable for rotors. It was found that this dip rolling process resulted in a considerable number of air pockets in the grooves and that they remained during hardening, so that the quality of the impregnation was also subject to strong, uncontrollable fluctuations in this dip rolling process.

i I I I III

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Since these quality fluctuations cannot be detected in the finished stators, one must again follow the lowest quality level when using the stators.

It is therefore an object of the invention to create an impregnation machine of the type mentioned at the outset, which enables the impregnation of such machine parts with smaller quality fluctuations.

This object is achieved according to the invention by the impregnation machine specified in claim 1.

The invention enables reductions in the quality fluctuations of machine parts impregnated in oerie using the inventive method.

The invention also makes it possible to achieve increased strength of the machine parts, since the impregnating agent is distributed more evenly over the winding and the slots or other areas to which the winding is to be firmly connected, and the winding is better strengthened and the connection between it and the slot insulation with the sheet metal package or other iron of the machine part is improved. Tests carried out with the new type of impregnation machine surprisingly showed

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5904 IP-EN - 10 -

unusually high strengths of the windings and the connection between them and the slot insulation with the sheet metal packages of the machine parts, both in stators and rotors, which could not even be achieved with the previously known impregnation processes. This is therefore completely surprising

¹ ^ and was not to be expected. The strength of the machine parts is also subject to significantly lower or almost no fluctuations in series production. Much higher centrifugal strengths and other advantages can also be achieved.

¹ ^. It is conceivable that impregnation using the new impregnation machine will in some cases allow the usual slot closure wedges to be omitted due to the high strength

of the machine parts.
20

The at least one tube provided according to claim 3 serves for rotational impregnation. This has the following advantage, among others. Even if in the case of slotted rotors the radius of the collector or the ^other current transmitter is larger than the radial distance of the slots from the longitudinal axis of the rotor, the winding can still be impregnated on both sides by means of the impregnating agent sprinkling the rotor.

Spray winding heads over the full height of the nuts 30

•&kgr;&igr;'

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- 11

or direct the impregnating agent to the places from where it can quickly penetrate completely into the winding heads and the slots. Although the rotor rotates with a horizontal longitudinal axis, the impregnating agent quickly penetrates into the slots and the entire winding. Stators and other rotors with windings containing coils can also be advantageously
rotational splash impregnation. In many cases, rotational splash impregnation can therefore be used alone to impregnate rotors or stators or can be combined with trickle impregnation and/or rotational dip impregnation. The combination enables even higher strengths of the windings and machine parts and even better quality uniformity in series production.
The rotation blasting and/or

Rotational dip impregnation can be carried out much more quickly than the dip rolling process described above.

The impregnating agent can preferably be a hardenable synthetic resin. The synthetic resins used in the known trickle impregnation processes and dip rolling processes can also be used in the invention. It can therefore preferably be

5904 IP-DE

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Epoxy resins or polyester resins can also be used, the viscosities of which can be suitably adjusted using the solvent. However, other synthetic resins or other suitable impregnating agents can also be used. For example, in some cases, dip paints, such as those used in the past to impregnate windings, can also be used in the process according to the invention. Synthetic resins are usually cheaper,

The new impregnation machine is equally suitable for impregnating both rotors and stators for electric motors and generators. The rotors or stators can preferably have grooved sheet packages into which wire windings or windings made of flat copper rods or the like are inserted. However, the invention is also suitable for rotors and stators in which the coils of the windings are arranged in a different way on the stator or rotor iron.

1'

ti

j &igr;

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It is advisable» after completing the ' application of the impregnating agent to the

machine part to continue rotating until the hardening or drying of the impregnating agent is complete. However, the rotation of the machine part can also be stopped earlier.

ig, preferably often expediently when the impregnating agent has dried or gelled to such an extent that it can no longer flow* The machine part can then be moved away from the place on the machine where the impregnating agent was applied and the impregnating agent can then be completely hardened or dried at another place on this machine or possibly at another place in the entire system, e.g.* in an oven, preferably in a continuous oven. In some cases it can also be provided that the

2Q Rotate the machine part immediately after completion

the application of the impregnating agent is completed and the %■ machine part is moved to another location,

where the applied impregnating agent is cured or dried.

25

The impregnating agent can preferably be used at 20 C

have a viscosity of approximately 30 to 12000 mPa s. If epoxy resin is used as an impregnating agent

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5904 IP-EN - 14

is used, its viscosity at 20 C ' may preferably be 40 to 700 mPa s.

Preferably, impregnating agents can be provided which are curable and have a gelling temperature which is below the curing temperature.

At the gelling temperature, the impregnating agent applied to the machine part gels within a short time and can then no longer flow. Impregnating agents can preferably be provided whose gelling temperature can be above 115 ⁰ C and whose hardening temperature can suitably be in the range of approx. 130 to 160 ⁰ C, in which case it can advantageously be provided that the supply of the impregnating agent to the machine part or its application to it is carried out at temperatures of the machine part of approx. 70 to 110 C.

Preferably, it can be provided that the impregnating agent is applied to the previously heated machine part. Preferably, it can be provided that the machine part is kept at a predetermined, constant temperature during the application of the impregnating agent, which can be done by regulating its temperature. Also during gelling, hardening or drying

5904 IP-EN - 15 -

of the impregnating agent, the temperature of the j-machine part can be conveniently controlled according to adjustable temperature setpoints.

The purpose of applying the impregnating agent to the heated machine part is to immediately reduce the viscosity of the impregnating agent after its application by heating it accordingly (the impregnating agent can still be at room temperature immediately before application, for example), and thus to penetrate more quickly and better into the

,_ winding, slots or other winding parts Ib

containing areas of the rotor or stator iron.

However, if the impregnating agent also

Room temperature already sufficiently low viscosity 20

It can also be provided that the machine part is not heated before the impregnating agent is applied. However, it can also be provided that the machine part is heated during the application of the

Impregnating agent on the machine part with the 25

Heating of the machine part begins.

During trickle impregnation, the machine part can normally be operated at speeds of approx.

5904 IP-DE -IR-

up to 20 rpm and/or in the case of rotational spraying and/or rotational immersion impregnation, normally preferably at speeds of approx. 5 to 12 rpm. In some cases, particularly with extremely large machine parts, speeds that deviate considerably from the stated numerical values may also be possible.

In the previously known trickle impregnation, the impregnating agent was applied in a time-controlled manner, i.e., the application of the impregnating agent to the

Machine part was carried out over a predetermined 15

period of time and was terminated when this period of time had elapsed. This can also be provided for in the impregnation machine according to the invention. However, it is even more advantageous to provide that

Drip impregnation on the machine part a 20

predetermined amount of the impregnating agent is applied and the impregnating machine can have a container for impregnating agent into which the

25 for each impregnation process

The specified amount of impregnating agent is filled in. This predetermined amount of impregnating agent ensures that the same amount of impregnating agent is always applied to each machine part in series production.

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&igr; · &bgr;

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5904 IP-DE

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of the same series and thereby the quality of the impregnation is evened out and improved. The amount of impregnating agent to be applied to the machine part during trowel impregnation can be determined in a simple way as follows: The impregnating agent is applied to the first machine part of the series in question until the impregnating agent begins to drip from the lower winding head. The amount of impregnating agent used at the time this dripping begins is

- ₅ Impregnating agent is measured and a slightly smaller amount of impregnating agent is then used for the trowel impregnation of the other machine parts of this series, so that for these other machine parts in series production the trowel impregnation is then terminated shortly before the impregnating agent begins to drip off.

It can be provided that the same impregnating agents are used for trowel impregnation and rotary dip or spray impregnation, which therefore have the same viscosity and the same chemical composition at room temperature. However, it is also possible to use a different impregnating agent for trowel impregnation.

5904 IP-DE

-&Igr;&dgr;-

It is advisable to provide different impregnating agents than those for rotary dip and/or spray impregnation, although these impregnating agents must be compatible with one another. In general, it is advisable to provide that impregnating agents of the same chemical composition are used for trickle impregnation and rotary dip or spray impregnation, but which differ in viscosity in order to better adapt to the different application methods by containing the solvent in different percentage amounts.

For trickle impregnation, it is particularly useful to arrange the trickle nozzle or nozzles in such a way that they only drip the impregnating agent onto the upper winding head, preferably onto its lower inside. The arrangement of the trickle nozzles is no longer critical, so that difficult and time-consuming adjustments and a high level of skill on the part of an operator are not required. Rather, it is sufficient and can therefore preferably be provided to adjust the at least one trickle nozzle, preferably two to four trickle nozzles, particularly useful three trickle nozzles, in such a way that they drip or drip the impregnating agent onto the lower inside of the higher-positioned winding head. However,

Other arrangements of the trickling nozzles are also possible, e.g. arrangements similar to the previously described trickling impregnation. The number of trickling nozzles can depend, among other things, on the casting size of the machine part. For larger machine parts, more trickling nozzles can be used than for smaller machine parts.

EN 27

The drawing shows exemplary embodiments of the invention. They show:

Fig. 1 is a side view of an impregnation machine according to the invention

Embodiment of the invention,

Fig. 2 shows a section of the machine according to Fig. I, but with the

,_ Clamping device for the

Drip impregnation inclined itft,

Fig. 3 a partially cut section of the machine according to

Fig. 1, which shows the clamped stator during rotary dip impregnation,

Fig. 4 is a partially sectioned detail of Fig. 1, but showing the clamped machine part during rotational explosive impregnation,

* &diams; * ««» · t ( t I &Phi; I

EN 28 '"""' '"*' "' '"' '

35

_t Fig. S is a partial section through Fig. A, seen &ogr;

in the direction of arrow B in an enlarged view, Fig. ₁ 6 a section of the machine according to

Fig. 1, in a sectional _view, but with the clamping device according to Fig. replaced by a clamping device for clamping a stator,

^ This stator is currently immersion impregnated '"

and the previous

Drip impregnation taken 5

Stator inclination dash-dotted line

is shown,

Fig. 7 in broken, schematic and partially

cutaway view of a rotor at the 20

Rotational diving and

Rotational explosive impregnation according to an embodiment of the invention.

/ The impregnation machine 10 according to Fig. 1 has a

'v 25

Frame, on the base 9 of which a machine stand 12 is fixed. A fork 35 of a clamping device 13 is pivotably connected to the stand 12,

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30

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< Il lit · · &igr; I · I &bull; II« « · I I

· 11 I * M I

5898 EN 29

- which are used to clamp and rotate a respective

impregnating, slotted rotor or rotor 17 provided with a wire winding consisting of coils, the slots of which run parallel to the longitudinal axis of the rotor. The coil sides of the j ₀ wire windings are inserted into the slots and their

over the grooved sheet package 57 protruding

₍ Areas form two winding heads 23. The rotor or

S' rotor 17 may also have a different design, e.g. a

Pole wheel of a generator or a synchronous motor

,_ Or another anchor or similar whose Ib

Winding has coils consisting of wires, y flat copper rods or the like, these

Winding can be inserted into a slotted laminated core or arranged in some other way on the rotor iron.

This machine can also be modified to suit your needs

Clamping device for impregnating stators, which also have windings with coils

( «e whose coils are also in slotted or 25

can be arranged in another way on the stator iron.

Below the clamping device there is a height-adjustable tray 19 for liquid

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5898 EN 30

c Impregnating agent 20 is arranged. To the right of the stand 12, a housing 18 is attached to the frame 11, which contains controls and regulations for the automation of this machine, which forms an impregnating machine, and a control panel. Among other things, it contains a state- and time-dependent

The program control device t ' 21 controlling the workflow is arranged.

j On the stand 12 there is a dosing vessel 22 for

- . p. liquid impregnating agent arranged in which, before each impregnation of a rotor 17 or stator 17* (Fig. 6), the amount of impregnating agent is filled which is dripped from the drip nozzle(s) 31 onto the $ relevant winding head 23 (Fig. 2) during the trickle impregnation of this machine part 17 or ₂₀ 17'.

As soon as this amount is used up, the trickle impregnation is stopped and the vessel 22 is again filled with the same amount of impregnating agent for the vC ₂ c trickle impregnation of the next machine part

17,17' of the series in question. When transitioning

to another series of stators or rotors I
!| the amount to be filled into the dosing vessel 22

Dosing quantity hay can be determined. 30

35

5898 EN 31

&bull; m · ■

Preferably, a total of three trickling nozzles

be provided, each of which is arranged on the bottom of a longer tube that is held in an adjustable position on this fork 35, which tube 32 is connected to the vessel 22 via a hose 33 and a pneumatically actuated JO shut-off valve 34.

These trickling nozzles 31 each have a fine outlet opening from which the impregnating agent, which is under pneumatic overpressure prevailing in the vessel 22, can trickle out.

The clamping device 13 has the fork 35, on whose left-hand vertical leg 36 a tip 37 is rotatably mounted, which

2Q recess in the left-hand front end of the shaft of this rotor 17. This tip 37 presses this rotor or runner shaft 38 with its right-hand conical front end against a driver tip 40, which engages in a recess in this

2g right-hand front end. This driver tip 40 can be slowly rotated around its longitudinal axis by means of a gear motor 41 and as a result the rotor rotates in a form-fitting manner with this tip slowly, for example at 8 to 20 rpm, in order to

OQ longitudinal axis. This driving point 40 is attached to a

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5898 OE

arranged on a plate 42 firmly connected to it, which 5

by means of arms a four-jaw chuck 43, into which

the collector 44 of the rotor 17 protrudes. This jaw chuck 43 presses against the collector electrical conductors for feeding the winding of the

Rotor 17 with its heating current, 10

the chuck 43 attached to this chuck

Slip rings and contacting brushes ' to a temperature controller 39 for controlling the

rotor temperature are connected.

15

This controller 39 is a temperature sensor

which is fixed to the fork 35 and measures the temperature of the rotor 17 without contact and enters it into the controller 39 as the actual temperature value.

A setpoint adjuster (not shown) that is in the 20

Housing 18 can be accommodated, gives the respective

The controller 39 then enters the programmed setpoint value of the rotor temperature and this then causes the heating of this rotor 17 to the set setpoint value.

To change a rotor 17, the tip 37 is pulled to the left, the rotor 17 is removed and a new rotor is inserted.

36

35

5898 EN33

An arm 47 is fixedly arranged on the right-hand side of the fork 35 and can be pivoted in the direction of the double arrow A in the vertical plane about a horizontal axis of rotation 14 that is perpendicular to the image plane. The pivoting is carried out by means of a lifting or servo motor 49, which can be a hydraulic piston-cylinder unit, a threaded spindle drive or the like. This lifting motor 49 is pivotally connected with its upper end to the stand 12 and with its lower end to the arm 47.

2g This allows the clamping device 13 to be swiveled continuously downwards from the horizontal position shown in Fig. 1, in which it rests against an abutment 50 on the stand 12 and the longitudinal axis of the rotor 17 is directed horizontally, into any programmable angular position in the vertical plane desired for trowel impregnation. The trowel impregnation can preferably be carried out at angular positions of the longitudinal axis of the machine part 17 or 17" (Fig. 6) of approx. 5 to 30°. An example of such an inclined position is shown in Fig. 2. The inclined position serves to drip the impregnating agent granulating from the vessel 22 during the trowel impregnation through the drip nozzles 31, of which only one

&ogr;« is shown. As can be seen from Fig. 2,

5898 EN34

this drip nozzle 31 shown is directed in such a way that the impregnating agent dripped vertically downwards from it drips onto the inner underside of the higher, right-hand winding head 23 of the rotor 17, while no impregnating agent is dripped onto the other, left-hand lower winding head 23. This lower winding head 23 only receives impregnating agent by inflow from the upper winding head 23 through the grooves of the rotor 17. If more than one drip nozzle is provided, all drip nozzles can also be directed onto the inner underside of the right-hand upper winding head 23. In the method according to the invention, it is normally not necessary to arrange one or more drip nozzles in such a way that they drip impregnating agent onto the outer top side of the upper winding head 23 and/or its inclined front side, since the position of the drip nozzles 31 is not critical in the method according to the invention.

The tray 19 enables the

Rotational immersion impregnation (Fig. 3) of the rotor 17 following the trickle impregnation (Fig. 2). It can also be used as a collecting tray for the impregnating agent

SSS8 OE35

β serves to impregnate the rotary cracks (Fig.4,5).

For the rotational spray impregnation (Fig.4,5) a straight nozzle pipe 51 is provided in this tank 19 horizontally and parallel to the longitudinal axis of the rotor 17 (if this longitudinal axis is horizontal, which is the case with

The impregnating agent pumped by a pump 52 can flow out of the pump 52 like _a liquid gushing or bubbling upwards to spray the rotor 17 from below. The delivery rate of the pump 52 and the arrangement of the holes in this embodiment are such that a single

the length of the row or rows of holes in this pipe 20

51 and extending slightly beyond it, a diagonally upwards directed surge or jet 63 of the impregnating agent delivered by the pump 52, see Fig.4 and 5. This wide surge 63

extends over the length of the winding of the rotor 25

17 and beyond that a little further laterally beyond the lower areas of the winding heads 23 to the left and right, so that this gush of impregnating agent, bubbling like a spring, also flows into the interior of the winding heads 23 and

Ö898 OE

Winding heads &egr;&ogr; in the areas where they pass the surge 63, are practically completely immersed in this surge and the relevant inner side areas of the winding heads 23 are also washed over by it. Since the impregnating agent flows in the surge, this "sprinkling" of the winding heads by the surge 63 is practically even more intensive than if the winding heads with the relevant areas were immersed in the

s impregnation bath 25 in the tub 19 |

would immerse themselves. 15

5898 EN37

Instead of the illustrated cross flow or surge 53 acting on the underside of the rotor 17, or in addition to it, jets of the impregnating agent can also be directed by means of position-adjustable jet pipes or nozzles 62 (Fig. 7) IQ onto other parts of the winding heads 23 or onto the

Grooves, preferably in the interior of the winding heads .- 23, as shown in Fig. 7 in an example

shows.

The tub 19 can be moved vertically from the position shown in Fig. 1 in its fully extended form by means of a lifting motor 54, e.g. a piston-cylinder unit, into the position shown in Fig. 3 and also into intermediate positions. In the position shown in Fig. 3, it is used for rotary dip impregnation of the rotor 17. In a slightly lower position, it can serve as a collecting tub 19 for rotary splash impregnation, see Figs. 4 and 5. The dosing tube 51 can be permanently fixed to the tub 19 so that it does not hinder ^the rotary dip impregnation, preferably at a distance to the side of the vertical longitudinal center plane of the rotor 17.

In this machine 10, it can be provided that the _Q rotor 17 is also only rotationally spray impregnated

&idr; 35

5898 EN38

or that it is drip-impregnated and rotation-dip impregnated and/or rotation-spray impregnated< So it has different impregnation options,

A drain line 55 is arranged on the tub 19, which leads to a storage container 56 for the impregnating agent, from which the pump 52 sucks in impregnating agent and returns it to the tub 19 and can also direct it into the nozzle pipe 51 if this inflow is opened for the rotational spray impregnation by means of a valve (not shown). A filter can also be arranged in this impregnating agent circuit. Even if rotational spray impregnation is not used, the impregnating agent can also be constantly circulated during rotational immersion impregnation.

As mentioned, the entire work process of the machine for impregnating a machine part can be fully automatic, whether including the replacement of the respective machine part 17 or 17' with a new machine part or without this replacement,

5898 EN39

Some examples of the impregnation process are described below.

1. Example.

,Q After it has been clamped in place, the rotor 17 is slowly rotated at a constant speed in the same direction of rotation, for example at 15 rpm. The temperature control device 39 is switched on and its setpoint is set to a temperature of, for example, 8C°

₁ ,-, at which the synthetic resin does not gel. As an impregnating agent, a hardenable polyester resin is assumed, which gels at about 125°C. As described above, an amount of

_ _n Polyester resin is automatically filled into the dosing vessel 22, which is constantly under constant pneumatic overpressure, from a storage vessel under higher overpressure. The temperature controller 39 switches the heating of the rotor

₉ ^ 17. Since the perceived actual value of the temperature of the rotor 17 at the beginning of the heating is at room temperature, the temperature of the rotor 17 now rises rapidly and reaches the setpoint value of 80 ⁰ C within 2 minutes, for example. The controller 39 now maintains

_&Ogr;&Lgr; Two-point control or continuous control the

I · I I I

5898 EN

Temperature of the rotor 17 at this setpoint of 80 ⁰ C. As soon as the actual temperature has reached the setpoint for the first time, this is reported to the program control device 21, which then, depending on the state of the temperature of the rotor 17, switches on the start of the trickle impregnation by opening the valve 34. Before the start of the trickle impregnation, the rotor 17 is pivoted by the program control device 21 by means of the lifting motor into a position shown in Fig. 2, inclined at an angle to the horizontal, in which the longitudinal axis of the rotor 17 is directed at an angle to the horizontal, for example expediently at an angle of up to 30°, which also applies to the impregnation of stators. This pivoting of the clamping device 13 is carried out before the trickle impregnation, preferably immediately after clamping or during the described heating of the rotor 17 or immediately before the start of the trickle impregnation. The dripping is then carried out until the amount of polyester resin in the vessel 22 has run out of it. This is sensed by a sensor and reported to the program control device, which then switches on the next program step depending on the condition, namely the pivoting of the clamping device 13 into the horizontal position.

&bull;II« III

5898 EN41

At the same time, the raising of the tank 19 into the position shown in Fig. 3 is controlled. The rotation of the rotor 17 continues uninterrupted. However, it can now usually be conveniently switched to a lower speed, which is more advantageous for rotary immersion impregnation, for example to 5 to 12 rpm.

During the subsequent rotary immersion impregnation, the rotor 17 is immersed in the liquid contained in the tank 19.

15 constantly circulated by pump 52

IR impregnation agent, which forms the impregnation bath 25 in the tub 19, is partially immersed. The level 26 of the impregnation bath has a constant height, for example as a result of an overflow in the tub 19.

The rotor 17 is immersed so far that its ZO

Collector 44 is not wetted with the impregnating agent, as this would require expensive rework. Of course, rotors with slip rings instead of collectors can also be used on this machine.

( impregnated.

25

35

5898 EN42

&dgr; In this embodiment, it is assumed that the rotor 17 may only be immersed in the synthetic resin in the tub 19 to such an extent that each groove of the laminated core 57, when it is located vertically below the horizontal rotor longitudinal axis, can still be immersed completely in this impregnation bath 25. It is therefore sufficient in this embodiment to immerse the rotor 17

after trickle impregnation, only additionally subjected to rotary immersion impregnation. However, if the grooves of the sheet stack cannot be completely immersed in the impregnation bath 23, it is expedient to provide additionally or on its own rotary explosion impregnation. However, the method according to the invention also brings about a considerable improvement in strength and a reduction in quality fluctuations if after trickle impregnation only

rotational dip impregnation and the nuts are not completely immersed in the impregnation bath 25.

For small and medium-sized machine parts, rotational immersion impregnation can be carried out for a time period of, for example, 30 seconds to 3 minutes. If rotational immersion impregnation is used, this time period can be extended for smaller and

&89Ö OE 43

- medium sizes also suitable up to a few
minutes, preferably
also ce. 30 seconds to 3 minutes long. This
However, vaccination times may also vary depending on

MääChiricnueil &udigr;&Ggr;&iacgr;&idigr;&iacgr; Viscosity ueä &Igr;&iacgr;&idigr;&iacgr;&mgr;&Ggr;&sgr;^&Ggr;&udigr;&bgr;&Ggr;&Pgr;&tgr;&Igr;&idiagr;&ugr;&dgr;&Igr;&dgr;

_n can also be shorter or longer, with

large machine parts may even last much longer, since I

These may have to rotate very slowly. |

k After the rotor 17 has been first rotated as shown in Fig. 2 Jj

drip impregnated and then according to Fig. 3

J-Oi

rotationally dip impregnated, the
Impregnating agent in its entire winding and in the

Grooves penetrated and also between the j

ö Slot insulation and the slot walls. f

I

After completion of the rotary dip impregnation, . |

the tub 19 is program-controlled into the position shown in Fig. 1 *'

shown position is lowered, but the |

Rotor 17 continues. The program control device 21 '&

now commands an increased temperature setpoint of the i

Rotor 17, which corresponds to the gelling temperature of the f

Polyester resin. This can be, for example, 125°C |

and the rotor 17 is now heated rapidly to 125°C | After this temperature is reached, it is

by means of the controller 33 for a predetermined
^a

5Ü98 QE

programmed period of time, e.g. 2 minutes. At the end of this period of time, the impregnating agent in the rotor 17 has gelled to such an extent that it can no longer flow. In principle, the rotation of the rotor 17 could now be stopped. Preferably, however, this rotation can be continued until the impregnating agent has finally hardened, since this slow rotation requires hardly any electricity and the uniformity of the impregnation can be improved as a result, since the continued rotation of the rotor 17 counteracts uneven temperatures in the rotor 17.

This hardening is preferably carried out in a rotor

long time until the hardening _B ,

the optimum achievable strength of the rotor 17 and its wire winding is reached. Depending on the size of the rotor, this can be 3 to 35 minutes. For stators, shorter hardening times can usually be provided, since they are not exposed to centrifugal forces like the rotors.

It should be noted here that the invention is suitable for stators and rotors of very different sizes, namely for small, medium and large rotors and stators. BöpWt it can

5898 EN

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15

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They are suitable for rotors and stators of electrical machines from 100 W or 100 VA to several or many kW or kVA, and possibly also for smaller electrical machines. The rotor or stator can therefore have weights from less than Ø Rg to possibly several or many tons.

The curing of the impregnating agent takes place over a predetermined period of time of, for example, 3 to 30 minutes at a higher temperature than gelling, for example for polyester resin usually at 135 to 160 ^° C. The program control device 21 commands a corresponding setting of the setpoint of the temperature controller 39 for curing.

After the curing period has elapsed, the impregnation has cured and the heating of the rotor 17 is automatically switched off. The clamping device 13 is opened and the rotor is replaced with a new, not yet impregnated rotor. The work sequence described then takes place again automatically.

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2. Example: If the rotor 17 cannot be immersed so deeply into the trough 19 because of the collector AA that the grooves

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t ti

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of the rotor can be completely immersed in the impregnation bath, it is expedient to provide rotational splash impregnation alone or in addition to rotational immersion impregnation. For the former, an embodiment is shown in Fig. 4 and 5, and for the latter, an embodiment is shown in Fig. For rotational splash impregnation according to Fig. 4 and 5, the pump 52 delivers impregnating agent into the nozzle pipe 51. The trickle impregnation took place unchanged before this rotational splash impregnation as described in Example 1. Subsequently, however, in the case of rotational splash impregnation alone, the tub 19 is transferred to the position shown in Fig. 1, in which the rotor is not immersed in the impregnation bath in the tub 19.

The nozzle tube 51 is in a position in which its openings are directed obliquely from below onto the underside of the rotor (Fig. 4, 5) and, when the pump 52 is running, spray it with a long and wide wave of impregnating agent 63. This wave extends over the entire length of the winding, including its winding heads, and over the winding heads to the left and

5898 EN

to the right. This surge, which springs out of the nozzle pipe 51 like a spring, completely floods the winding heads 23 in the area where they pass through it, so that the impregnating agent penetrates into the interior of the winding heads as if the relevant areas were completely immersed in an impregnating bath. However, the level 26 of the impregnating bath is actually located at a distance below the rotor 17. This surge 63 thus intensively sprays the winding heads 23. They are practically immersed in the surge as they pass through it.

The impregnating agent thus penetrates intensively into both winding heads 23 and also penetrates into the grooves of the sheet metal package 57. This rotational explosive impregnation following the trickle impregnation can be carried out for e.g. 30 seconds to 2 minutes or, depending on the machine part and other conditions, even shorter or even longer. The tank 19 is then lowered again and the impregnating agent on the rotor 17 is gelled and hardened again as described above.

The nozzle pipe 51 is due to its permanent arrangement in the tub 19 according to Fig. 5 not

5898 EN48

vertically below the longitudinal axis of the rotor 17, but also

To enable rotary immersion impregnation without having to remove it, it is offset laterally but parallel to the longitudinal axis of the rotor. If the nozzle tube 51 for rotary immersion impregnation is removable, it can also be arranged vertically below the longitudinal axis of the rotor 17.

It is surprising what a significant improvement in the strength of the winding and the centrifugal strength of the rotor 17 this method of combined trickle and
Rotational dip impregnation or trickle and rotational spray impregnation.

The commonly used slot insulation, _p

which can consist, for example, of strips of thin insulating material, are intensively bonded to both the slot walls and the winding parts located in the slots by the impregnating agent. The strength of the rotor 17 is unusually high, which could not be remotely achieved with the previously known methods described at the beginning.

gO 3.Example.

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5898 EN49

This impregnation machine 10 can also be used only for rotary immersion and/or rotary burst impregnation. In this case, the program control device is set so that after heating the respective machine part e.g. 17* to the temperature intended for application, it immediately begins rotary immersion impregnation and/or rotary burst impregnation, which is carried out with the longitudinal axis of the rotor 17 in a horizontal position. The time period during which

rotation-dip and/or rotation-blast impregnated 15

is usually advisable to provide for a longer period than with previous trickle impregnation, expediently so long that the impregnating agent can reach the winding heads and the coil sides located in the grooves

has been thoroughly dripped through. After that, the gelling process 20

and curing of the impregnating agent applied to the rotor 17 is controlled as described.

The method according to the invention is suitable not only for rotors but also for stators.

If stators are to be impregnated, it can be provided that the clamping device 13 of the machine 10 according to Fig. 1 is replaced by a clamping device suitable for stators 17'. An example

5898 EN 50

Such a clamping device 13 is shown schematically in Fig. It has a rotatably mounted jaw chuck 43' which can be driven to rotate about its longitudinal axis and which is ^inserted into the bore 59 of the stator 17' and clamps the laminated core 57' concentrically to its longitudinal axis. In a position of the stator 17' inclined to the horizontal, shown in dash-dotted lines in Fig. 6 as an example, trickle impregnation can then be carried out again. The inclination of the longitudinal axis of the stator to the horizontal can also be approximately 5 to 30° here as with trickle impregnation in general and can be adjusted by pivoting the clamping device.

For trickling, the trickling nozzles 31 in this embodiment are set so that they trickle the impregnating agent only onto the underside of the higher positioned winding head 23. However, other positions of at least one trickling nozzle can also be provided if necessary.

The machine 10 can also be used in the fully extended position shown in Fig. 6 for QQ rotational dip impregnation and/or

S898 EN 51

Impregnating agent jets should be directed as
in an example in Fig. 6 dash-dotted
These spray nozzles 51' spray the
Insides of the WicSceMopfe 23 at their lower

c Rotational spray impregnation can be used*

During rotary dip impregnation, the stator can 17'

always so far into the | in the tub 19

Imprsgrtisrbsd 25 gingetaueht grazing. that the respective i«

vertically below the horizontal longitudinal axis of the r

Stator 17* axial slot of the laminated core 57' p

completely immersed in the impregnation bath, as the |

Stator has no commutator. In Fig. 6 |

the level 26 of the impregnation bath 25 in the §

Tub 19 at the level of the horizontal lower tangent to ^{

;

the circular cylindrical bore 59 of the laminated core 57' 1

of the stator 17', into which a rotor is later inserted I

A slightly higher or lower ij

Position of this mirror 26 can in some cases |

be appropriate. ' !

e

You can also rotationally spray impregnate the with f

horizontal longitudinal axis of slowly rotating stator _k

17'. For this purpose, both I

Winding heads 23 Spray nozzles or jet pipes 51' to §

ä|

directed spraying of both winding heads 23 with f

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20

25

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The tank can be lowered so far that the level 26 of the impregnating liquid in it is below the stator 17', as indicated in dash two. However, it is also possible to allow the winding heads with their lower areas to be partially immersed in the impregnating bath, so that rotational immersion and spray impregnation take place at the same time.

If necessary, during trickle impregnation it can also be provided that at least one trickle nozzle 31 also sprinkles impregnating agent onto a location other than the lower inner area of the higher winding head, for example the slanted front side or the top of the higher winding head area.

In Fig. 7, a rotor 17 is shown in section, which is simultaneously impregnated by rotational immersion and rotational explosion. Its two winding heads 23 are partially immersed at the bottom end in the impregnation bath 25 located in the tub 19. Immersion even deeper is not possible because otherwise the collector 44 would also

35

5898 EN

would be immersed in the impregnation bath 25, which is undesirable because it would otherwise have to be freed from the adhering impregnating agent after impregnation and hardening.

IO

15

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For rotational spray impregnation, a jet pipe or a spray nozzle 62 is directed obliquely upwards at each of the two front sides of the laminated core 57 of the rotor 17, as shown, directing thick jets of the impregnating agent, which can again preferably be synthetic resin, onto these front sides below the rotor shaft 38, which thus reaches the lower inner sides of the winding heads 23, intensively impacting them. As a result, the winding on both winding heads 23 is intensively soaked with impregnating agent both on the outside and on the inside, which also penetrates intensively into the slots and the coil sides located there, and also between the slot insulation and the slot walls. Rapid, intensive impregnation is achieved. This combined rotary immersion and spray impregnation needs to be carried out very quickly, for example half an hour to a few hours, especially if the rotor was previously drip impregnated. It may also take even less time.

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5898 EN

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5 or even longer time programmed It can in many cases also be used without prior trotting impregnation for impregnating rotors and stators.

Claims (1)

_t ■ * ϳ · ■ a · · · IP-DE -1- Protection claims Impregnation machine for impregnating machine parts intended for electrical machines with flowable, electrically insulating impregnating agent, preferably hardenable synthetic resin, which machine parts are preferably slotted stators or rotors, which have coil windings, preferably wire windings, whereby the machine part can be impregnated by trickle impregnation in that it can be rotated about this longitudinal axis with its longitudinal axis directed obliquely to the horizontal and during rotation, impregnating agent can be dripped onto its winding head, which is positioned higher than the other winding head due to the oblique position, so that this impregnating agent penetrates the winding and is distributed over the winding, characterized in that the impregnation machine has at least one clamping device (13) for clamping a machine part (17; 17') to be impregnated in each case and a drive device (41) for rotating of the respectively clamped machine part about its longitudinal axis and a trough (19) for impregnating agent arranged below the clamping device. IP-EN -2- 2. Impregnation machine according to claim 1, &ogr; characterized in that the clamping device (13) can be pivoted from a horizontal position into at least one position inclined to the horizontal and that it has at least one dripping eyelet (31) for impregnating agent, which is preferably adjustable in position and is preferably arranged in such a way that, when the clamping device (13) is inclined, impregnating agent is applied to the inside of a winding head of a clamped Machine part for trickle impregnation eaves]bar 15 is. 3. Impregnation machine according to claim 1 or 2, characterized in that it has at least one pipe (51; 5i<_; 62) or the like, which has at least one outlet opening for impregnating agent, from which impregnating agent can flow out under pressure for rotationally explosively impregnating clamped machine parts (17; 17'), whereby this pipe (51) is arranged in such a way that it can apply impregnating agent to the rotating machine part (17; 17') clamped in the clamping device (13) with a horizontal axis of rotation at least at its two winding heads (23). IP-DE -3- 4. Impregnation machine according to claim 3, characterized in that the rod (51) is arranged in the tub (19). Impregnation machine according to claim 3 or 4, characterized in that the tube (51) is arranged such that its at least one outlet opening is provided for spraying the machine part (17) clamped in the clamping device (13) from below or for applying impregnating agent to the winding heads at an angle or from the inside. 6. Impregnation machine according to one of the preceding claims, characterized in that it has a program control device. 7. Impregnation machine according to one of the preceding claims, characterized in that the trough (19) and/or the clamping device (13) is height-adjustable. Impregnation machine according to one of the preceding claims, characterized in that it has electrical connections for connecting the windings of the machine parts for the purpose of supplying them with electric current for heating them, this current preferably being adjustable by means of a temperature control device (39) for controlling the temperature of the machine parts. 5904 IP=EN I ° 9; Impregnation machine according to claim 8, characterized characterized in that the clamping device (13) has slip rings and grinding brushes for supplying the electric current used to heat the machine parts (17). IO 10. Impregnation machine according to one of the preceding claims*, characterized in that it has a vessel ( ²² ^ * ^Uni) for each metered application of an amount of impregnating agent to be applied to the respective machine part during the respective trowel impregnation.