KR20050012285A - Method and system for assembling an electricity generating unit - Google Patents

Abstract

The present invention relates to a method and system for assembling an electric generating unit consisting of a generator and in particular a reciprocating engine as a drive device for centering an internal stator having an air gap and arranged inside an outer rotor. The method includes the following steps: installing an external rotor on a drive motor and connecting the rotor to a drive system of the motor; Inserting at least two centering bolts circumferentially offset into a centering groove provided in the rotor / stator to partially receive the centering bolt connecting the air gap 33 in radial direction; Positioning the stator in the center of the rotor by inserting a stator along the centering bolt inside the rotor; Securing the stator to a generator housing and securing the generator housing to a connection housing of a drive motor; Removing the centering bolt from an air gap.

Description

METHOOD AND SYSTEM FOR ASSEMBLING AN ELECTRICITY GENERATING UNIT}

The present invention relates to a method and system for assembling an electricity generating unit consisting of a reciprocating engine as a generator and a drive device. The invention relates in particular to centering an inner stator having an air gap and arranged inside the outer rotor.

Electricity generating units consisting of a generator and a drive reciprocating engine, and assembly of such units are known.

For example, German Laid-Open Patent Application 100 10 248 of the same applicant describes an electric generator of this type with a permanent magnet disposed inside the rotor to excite a fixed armature winding and a generator, in which case The rotor forms an oscillating wheel of a diesel engine as an external armature, and the stator supports the armature winding and is disposed inside the rotor. The rotor is also mounted to the fan wheel, which is flanged to the crankshaft of the drive motor at the front. The stator is formed as a soft iron plate screwed with the inner ring of the generator housing cover provided on the discharge side by means of a stator screw which supports the armature winding and is guided in the soft iron plate through the bore and tightens the soft iron plate together. The rotor is formed as a soft iron plate that supports a permanent magnet to form a rotating magnetic field, and is screwed around the fan wheel multiplely with a fastening screw guided in the soft iron plate through the bore and tightening the soft iron plate together. .

For assembly of the electrical generator the rotor is fixed to the fan wheel by means of a set screw, which is flanged to the crankshaft of the drive motor at the front. In that case, the generator housing is attached to the motor side connecting housing by a fixing screw. To secure the stator to the generator housing, the stator is secured to the housing cover of the generator housing by stator screws. Finally, the housing cover is mounted on the generator housing and secured there by screw bolts.

Since the stator is only positioned indirectly inside the rotor, the stator can only be centered directly directly within the rotor. As such, the central placement of the stator is such that the assembly tolerances, that is, the assembly tolerances when fixing the rotor to the fan wheel, the generator housing to the motor-side connection housing already mounted on the fan wheel or crankshaft with assembly tolerances Assembly tolerances when fixing, assembly tolerances when fixing the stator to the housing cover, and assembly tolerances when fixing the housing cover to the generator housing. The assembly tolerances added in the worst case make the centrally placed assembly of the stator quite difficult. Improved central positioning of the stator can only be achieved by fixing the stator directly to the generator housing, which improves at least the assembly tolerances when securing the stator to the housing cover and the housing cover to the generator housing. Assembly tolerances at the time can be avoided. However, a definite solution can only be obtained by placing the stator directly in the center of the rotor.

However, accurately positioning the stator in the center of the rotor while maintaining the air gap accurately is inevitable for the full functioning of the generator. Each ignition impact of the reciprocating engine causes bending of the crankshaft, which is transmitted to a fan wheel flanged to the crankshaft and a rotor mounted to the shaft. If the rotor deflects and impinges on the stator in the case of such deflection, serious wear or functional loss of the electricity generating unit must be taken into account within a short time. This rotor deflection cannot be completely suppressed but must be avoided. This prevention of deflection can be achieved by means of air gaps measured between corresponding sizes between the rotor and the stator, but for this purpose the stator needs to be correctly centered. Even if the stator deviates only slightly from the preset center position, it can no longer prevent the rotor from colliding with the stator during rotor deflection caused by the ignition impact.

The object of the present invention is to overcome the disadvantages of placing the stator directly in the center of the rotor as is known in the prior art. This object is achieved by the features of the independent claims in accordance with one proposal of the invention. Preferred embodiments of the invention are described by the features of the dependent claims.

According to the invention, a method is provided for assembling an electricity generating unit consisting of a reciprocating engine as a generator and a drive device, in particular for centrally arranging an inner stator having an air gap and arranged inside the outer rotor. Includes the following steps:

First, securing an external rotor of a generator on a drive motor and connecting the rotor to a drive system of the drive motor; Such a process may be performed, for example, in a form in which a fan wheel and a rotor fixed to the crankshaft of the driving motor are connected at the front.

Then, in the radial direction, at least two centering bolts are circumferentially offset inside the centering groove provided in the rotor / stator to partially receive the centering bolt connecting the air gap. In other words, the centering groove is formed such that the centering bolt inserted in one centering groove has a portion projecting radially from the centering groove.

The stator is then centered inside the rotor, in which case the stator is inserted along the centering bolt inside the rotor. If the rotor and stator have a centering groove, when centering the stator, the centering bolt already inserted inside the centering groove of the rotor or stator is inserted into the centering groove of the rotor and stator facing the air gap beyond. .

The stator is then fixed to the center position of the generator housing. For this purpose the stator can be fixed to the housing cover to be fixed to the generator housing. The generator housing is installed in the motor side connection housing before or after the stator is fixed.

Finally, the centering bolt must be removed from the air gap. This removal process can be accomplished, for example, by the centering bolt being drawn out of the generator through a hole disposed in the housing cover.

If the centering pin is in an unusual shape, ie in the form of a cylinder part cut along the cylinder axis with a flat cutting surface, the centering pin is rotated until the centering pin no longer has a part projecting from the centering groove in the radial direction. There is a possibility. The precondition in this case is that the centering bolt must be able to fully occupy one centering groove. That is, first, when the centering bolt is in the form of a cylinder as described above, the flat cut surface should be disposed inside the cylinder such that the maximum vertical distance from the cut surface to the circumferential point is less than or equal to the depth of one centering groove. The centering bolt must then be secured in this position by a suitable restraining means, such fixing can be effected, for example, by a spring.

Very preferably, according to the invention the stator is arranged directly in the center of the rotor. The assembly tolerances that may appear when assembling the rotor and other parts playing their respective roles in the central positioning of the stator as known in the prior art are not important in this case.

In addition, a system suitable for carrying out the method according to the invention is proposed. The system comprises an electricity generating unit consisting of a reciprocating engine as a generator and a drive device, in particular a synchronous generator and a diesel engine, and a centering pin provided for centering the stator inside the rotor. The generator includes an external rotor installed in the drive motor and an internal stator fixed to the generator housing. The system according to the invention has at least two centering grooves on the circumferential surface adjacent to the air gap, the rotor or stator being open toward the air gap and running along an axis, in which a centering bolt is radiated. It is partially received in the direction, characterized in that the other peripheral surface is supported in the center on the centering bolt. In other words, the centering groove is formed such that the centering bolt has a portion protruding radially from the centering groove.

In a particularly preferred embodiment of the present invention, centering grooves are provided on two circumferential surfaces, and centering bolts are partially received in the grooves.

The rotor can be installed on a fan wheel, which is fixed to the crankshaft of the drive motor at the front. The rotor is also formed as a soft iron plate that is permanently screwed around the fan wheel by means of a fastening screw which guides in the soft iron plate through the bore and supports the permanent magnet to form a rotating magnetic field. Can be.

The stator can be formed as a soft iron plate screwed with the inner ring of the generator housing cover provided on the discharge side by means of a stator screw which supports the armature winding and is guided in the soft iron plate through the bore and tightens the soft iron plate together. have.

The invention is described in detail with reference to the embodiments, in which case the accompanying drawings are cited.

1 is an axial cross-sectional view of the motor-generator unit cut along the cutting line I-I of FIG. 2.

FIG. 2 is a schematic diagram illustrating the stator and the rotor in a state in which the motor-generator unit is cut along the cutting line II-II of FIG. 1.

The electric machine shown in FIGS. 1 and 2 and forming the current generator is associated with a unit consisting of a drive motor and a synchronous generator. The diesel engine is preferably treated as a drive motor, and only the end portion of the diesel engine 1 on the connection side of the diesel engine is shown in broken lines. The fan wheel 2 is attached to the front of the crankshaft 1 by the screw 3. The fan wheel 2 draws airflow according to the arrow L, along the arrow S1 for the cooling of the motor and along the arrow S2 for the cooling of the generator. The blade 4 is provided.

The motor side connecting housing 5 surrounds the space provided with the fan wheel 2 therein radially outward; The fan wheel is open towards the motor and on the opposite side comprises a ring-shaped flange 6 with a spiral bore for screwing in a set screw 7 for connecting the cylindrical generator housing 8, the generator housing. In the inside, the fixing screw is fixed to the flat surface from the front. The fastening screws 7 are distributed over the circumference at the inner surface of the generator housing 8 and tighten through the entire housing length.

The generator housing cover 9 is provided at the end of the generator housing 8 on the left side in the figure, to which the stator 11 of the generator is fixed.

Eight fixing screws 7 are provided in the circumference according to the present embodiment, while six stator screws 17 are sufficient for fastening the stator, which screws are spaced through the bores of the soft iron plate. Screwed on). Inside the corresponding cut-out 38 of the soft iron plate of the stator 11 is housed a winding branch of the generator's three-phase current winding 28.

The stator 11 is likewise surrounded by a rotor 29 consisting of a soft iron plate, the soft iron plate being tightened together by a tightening screw 30, which is tightened by a motor side spiral end 31. Screwed into the corresponding spiral bore of (2). Between the fan wheel and the associated side of the rotor 29, the support sleeve 32 which slides over the fastening screw 30 is fixed. As such, the rotor 29 is rotatably coupled with the fan wheel 2. The rotor forms an elongated air gap 33 about 2 mm wide with respect to the stator 11 around its inner circumference. Further, the rotor 29 has a pocket penetrating in the axial direction and proceeding in a substantially circular shape within two segments, in which a magnet 35 is inserted from both sides, especially in this embodiment FIG. 2. As can be seen, two rows of magnets each consisting of ten magnets 35 arranged side by side are inserted for each pole, which are responsible for the exciter of the generator.

The figure according to FIG. 2 shows the rotor 29 fixed to the fan wheel 2 by four tightening screws 30. A cut-out formed in a polygon is provided around the inner circumference of the rotor 29, the cut-out forming an open pocket, in which a magnet 35 is inserted into two poles inside the pocket. In this pocket region the inner contour 36 of the rotor 29 together with the outer contour 37 of the stator 11 forms an elongated air gap 33. In addition to the contours of the soft iron plate forming the rotor 29, the contours of the soft iron plate including the cut-out 38 to receive the winding wire and forming the stator are also shown.

As can be seen in FIG. 2, the centering groove 39 with a cross-sectional profile in the form of a partial circle is hollow around the inside of the rotor to position the stator 11 in the center of the rotor 29. . On the outer circumference of the stator at a position opposite to the centering groove 39 of the rotor, the centering groove 41 is empty, which groove is likewise formed with a cross-sectional profile in the form of a (circularly cut) partial circle. have. There is an air gap between the centering grooves. Centering bolts 40 inserted into the centering grooves 39 and 41 of the rotor and stator connect the air gaps 33.

In order to assemble the electricity generating unit, the rotor 29 is first installed on the fan wheel 2 of the drive motor. Two cylindrical centering bolts are then inserted into the centering groove 39 of the rotor. Since the centering groove of the rotor 29 is formed in the form of a partial circle, the groove does not completely surround the centering bolt in the radial direction, so that a part of the centering bolt protrudes radially from the centering groove. The stator 11 is then inserted into the rotor along a portion of the centering bolt protruding from the centering groove 39 of the rotor, which is to be inserted into the centering groove 41 of the stator, and external to the rotor. Spaced at equal intervals. That is, it is disposed in the center of the rotor 29 inside. In this case the inner circumferential surface of the rotor 29 and the outer circumferential surface of the stator 11 are adjacent to the centering bolt 40. The stator 11 is then screwed into the housing cover 9 in the centered position, which is fixed to the generator housing 8. Finally, the centering pin 40 is removed from the generator through the hole 42 in the housing cover 9.

The invention is not limited to the described and claimed embodiments. In particular, the relative positions of the rotor and the stator can be replaced symmetrically. That is, the rotor may be formed as an internal rotor and the stator as an external stator.

Claims (15)

A method for assembling an electricity generating unit consisting of a generator and a reciprocating engine as a drive device, in particular for centering an internal stator having an air gap and arranged inside the outer rotor, Installing an external rotor (29) on the drive motor and connecting the rotor to the drive system of the motor; At least two said circumferentially offset inside a centering groove 39; 41 provided in the rotor / stator to partially receive the centering bolt 40 connecting the air gap 33 in a radial direction. Inserting the centering bolt 40; Placing the stator (11) in the center of the rotor (29) by inserting the internal stator (11) inside the rotor (29) along the centering bolt (40); Fastening the stator (11) to the generator housing (8) and fixing the generator housing to the connection housing (5) of the drive motor; And Removing the centering bolt (40) from the air gap (33). The method of claim 1, The rotor is mounted on a fan wheel (2) fixed to the crankshaft (1) of the drive motor from the front side, characterized in that the electric generator unit assembly method. The method of claim 1, The stator is characterized in that it is fixed to a housing cover (9) to be fixed to the generator housing (8). The method of claim 1, The centering bolt (40) is characterized in that it is removed from the generator through a hole (42) disposed in the housing cover (9). The method of claim 1, The centering bolt (40) is characterized in that it is pulled out of the air gap (33) for removal, electric generator unit assembly method. The method of claim 5, wherein The centering bolt (40) is turned through a hole (42) disposed in the housing cover. Claim 1, comprising an electric generating unit composed of a reciprocating engine as a generator and a drive device, in particular a synchronous generator and a diesel engine, wherein the generator comprises an external rotor installed in the drive motor and an internal stator fixed to the generator housing. In a system suitable for carrying out the method according to any one of the preceding claims, The rotor 29 or the stator 11 extends along an axis, opening toward the air gap, at least two circumferentially displaced circumferential surfaces adjacent the air gap 33, 39. 41. Is provided in the centering groove, the centering bolt 40 is partially accommodated in the radial direction, On the centering bolt (40) is characterized in that the other circumferential surface is centrally supported. The method of claim 7, wherein The centering groove (39; 41) is provided on two circumferential surfaces, and the centering bolt (40) is partially received inside the centering groove. The method of claim 7, wherein The rotor (29) is characterized in that it is installed on a fan wheel (2) fixed to the front of the crankshaft (1) of the drive motor. The method of claim 7, wherein The rotor (29) is characterized in that it is formed as a soft iron plate supporting the permanent magnet (35). The method of claim 7, wherein The stator (11) is characterized in that it is formed as a soft iron plate supporting the armature winding. The method of claim 7, wherein The centering groove (39; 41) is characterized in that it has a cross-sectional profile in the form of a partial circle. The method of claim 7, wherein The centering bolt (40) is characterized in that the cylindrical. The method of claim 7, wherein The centering bolt (40) is characterized in that it is provided in the form of a cylinder having a flat cut surface and cut along the cylinder longitudinal axis. The method of claim 7, wherein A system, characterized in that a hole (42) for removing / turning the centering bolt (40) is provided in the housing cover (9) of the generator.