JPS63181634A - Electric machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to electric machines including both rotating machines such as motors and generators, and stationary machines such as transformers. This invention relates to an iron core and a method and apparatus for manufacturing the same.

[Background of the invention]

When making electric machines such as motors, generators, and transformers, the rotor core and the transformer stator core are
They are punched out from metal sheets (electromagnetic steel sheets, etc.), then laminated and crimped together to form one pancage.

Since the individual punched pieces have a round shape, a large amount of scrap is generated. Furthermore, the die-cut package must be tightly crimped to prevent energy loss and frequency-induced hum. For this purpose, a cast iron pressure plate is usually required at the end of the package, which are assembled together by means of a bolt or other connection through suitable holes in the punching piece and the end plate. . This, in addition to the aforementioned waste of material, requires considerable manufacturing effort and requires the use of prefabricated auxiliary parts.

It has also been proposed to wind a strip of steel with openings for accommodating the field windings to form the core for the axial flux generator. In order to minimize air gaps, the width of these openings is limited to less than 2 m at their top. It is important that these punched openings are located in such a way that passages are formed in the wound coil that extend in the radial direction of the core. Because the field winding must be inserted through a narrow gap at the top of the aperture, simple winding machines are not available. Therefore, the field winding is typically wound by hand, which is inaccurate and time consuming, resulting in high costs.

[Purpose of the invention]

The aim of the invention is to reduce as much as possible material waste and manufacturing effort and to eliminate additional parts that are not essential to the functioning of the machine.

Another objective is to provide an efficient electrical machine, characterized by simple design and low manufacturing costs, with significant savings in iron for the core and copper wire for the winding, resulting in high torque and low slip. It is also an object of the present invention to provide a method and apparatus for manufacturing this machine.

a helically wound coil consisting of a strip having transverse slits extending from one edge partway through its width, the slits in each layer of said coil cooperating to form an electrical winding. separated by tongues to form slots extending generally in the radial direction of the coil for accommodating the electrical windings, the electrical windings being received within the slots, and the tongues forming slots extending generally in the radial direction of the coil for accommodating the electrical windings; the upper end of the slot being bent inwardly toward the slot, thereby closing the upper end of the slot so as to substantially eliminate an air gap.

To prevent the coil from unraveling, it is desirable to provide ears on each turn of the strip at the beginning and end of the coil.

The space left in the slot may be filled by casting aluminum or an aluminum alloy, especially in the case of a rotor for a squirrel cage motor.

The method for producing this core includes: feeding a strip of electrical steel sheet from a roll; straightening it; cutting off part of the width of the strip over a predetermined length to the depth of the slot and tongue; punching out a lug at a distance corresponding to one winding layer of the coil from the tip of the strip; punching out an opening for receiving the lug at a distance corresponding to another winding layer; one edge; transverse slits extending from the point of origin and separated by tongues of increasing width are punched out from the striking part of said strip, whereby the strip is continuously wound into the shape of a coil. , the slits cooperate to form a slot for accommodating a substantially constant width field winding extending generally radially across the coil;
further forming a narrow strip portion; forming cooperating ears one turn apart from the end of the strip and near the end of the strip; Cut off the wound portion of the strip; insert and insulate the field winding; and fold the tongues radially inward against the coil to close the slit at its upper end so that the air gap is substantially It consists of steps to ensure that no residue remains.

It will be seen that the core is made in this manner and the air gap is left open for the tongue-shaped field winding. If desired, the winding insertion space may be made even larger by bending the tongues radially outward before the insertion step is performed.

Insulation may be applied within the slot before and after the winding is inserted.

Apparatus for making iron cores includes means for feeding the strip from a supply roll to a punching and coiling station, and transport means for delivering the wound core to a subsequent working station, which station applies a field to the slots in the coil. a slot closing station with means for inserting a winding and means for closing an air gap in the slot; said punching and winding station includes a cutter for reducing the width of the strip; first punching means for punching a window corresponding to the strip; second punching means for punching a transverse slit in the strip for receiving a field winding; and winding the strip to form a coil; the means and the winding means are driven by a common drive mechanism and are connected via an indexing mechanism;
This makes it possible to form slits at predetermined angular intervals around the outer circumference of the coil, and the slot closing means comprises a press for folding the tongues separating the slots into the inside of the coil. The transport means are configured to transport the cores sequentially to the next work station.

〔Example〕

The form of the iron core according to the present invention is shown in FIGS. 1 to 5. FIG. 1 shows a winding of stamped metal strip with a ring of open slots 3 separated by tongues 9 and ending with an air gap 4 for the stator or rotor of an axial flux motor. The iron core 2 is shown, and the slot 3
is adapted to accommodate a field winding configured to fill the slot as completely as possible. The insertion of the winding is facilitated in this embodiment by bending the tongues 9 outward by an angle α, so that the slot 3 is designed wider at the top. After the winding has been inserted, the tongue is bent inward to the axis of the core to an angle β, as shown in FIG. A substantially closed space 8 is formed. To assist in this closure, the slit in the strip forming slot 3 is narrowed at its upper end. This winding space 8 can, for example in the case of squirrel cage motors, be filled with aluminum in sequence by casting.

FIG. 3 shows another example of the iron core 2 in which the tongue pieces 9 are not bent outward. In this embodiment, the slit may be unencumbered in the air gap region to facilitate insertion of the winding. In this case, the slot is also closed by folding the tongues inward after the winding has been inserted.

This situation is shown in FIG. 4, where the air gap 6 of the slot 5 is substantially closed.

FIG. 5 shows the completed stator core with the field windings inserted into the slots 11 and the air gap 12 closed by the inward bending of the tongues.

Closing the air gap 12 is important for increasing machine efficiency and reducing slip.

To form radial slots in the wound strip on the mandrel, it is necessary to provide the slits as shown in FIG. This figure shows a molded flat strip 7
Indicates 0. Along this main length, transverse slits 74 are formed inwardly from one edge and are separated by tongues or teeth 75.77. These slits all have the same width, but the width of the tongues or teeth between the slits is from the leading edge 73 to the trailing edge 80 of the strip.
The slits gradually increase towards be able to. In order to prevent problems when starting the winding automatically and to smooth the finish, the strip is cut out in its leading and trailing end regions over a predetermined length from one edge to the depth of the slit. ing.

An ear 71 formed by punching in the tip region of the strip is for engaging a pin on the winding mandrel, and a second ear 72 is formed at a distance corresponding to one turn of the coil. and this causes the latter ear to be pressed together with the first ear as the mandrel rotates;
engage with each other. To ensure the smoothness of the coil,
A window 76 is made in the strip at a distance corresponding to one more turn of the coil. The rear end region of the strip is likewise provided with a pair of corresponding ears 78 and 79, which serve to retain the shape of the coil. These ears 71, 72, 78, 79 and windows 76 are all punched out with the same punch.

To form a strip of this shape, the strip is passed from the feed port 36 to the straightening device 52, as shown schematically in FIG. Through the medium reduction cutter 53 and the tool punch and die, the slit forming punch and die 55
．． 56.

This slit punching and coil winding means is
Further details are shown in FIG. 9, which also shows the mechanism for gripping the strip to automatically initiate winding.

The strip 90 passes over a stationary die 93 and under a punch 94. die 93 is mounted on roller 89;
The roller initially rests on the mandrel 103 but as the coil grows it rests on the outer circumference of the coil and is adjustable in the tangential direction of the coil by means of the slot 100. This adjustment aligns the slits in each winding layer to match and allows the slots in the core to be precisely radial or diagonal if desired. The punching includes a ram 95 and a connecting rod 96 eccentrically attached to the drive shaft 125.
It is done through. A squeeze receiver 104 is installed below the die, and counter pressure on the die is applied by a piston rond 101.

After punching, the strip is rolled up onto a mandrel 103. The mandrel is rotatably attached to the slide plate 112 and moves downward as the diameter of the coil increases.

During start-up, the strip is brought into engagement with the shaft of the mandrel at level 91. The tip of the strip is passed under a roller 98 carried on a link driven by a piston-cylinder cylinder device 99, where it is bent towards the mandrel to engage the first ear with a bin 102 projecting from the mandrel. held by. Then piston 9
9 returns the roller 9B to its initial position. Coil winding continues until the mandrel axis reaches level 92, at which point coil 97 is complete and removed from the mandrel. That is, the mandrel is constructed in such a way that it can do this.

In order to achieve the desired alignment of the slits in each winding layer of the coil, the slit punching mechanism and the coil winding mechanism have common drive means and are linked to each other via an inch-nox mechanism. A rear view of this mechanism is shown in FIG.

A main drive shaft 125 (see FIG. 8) driven by a motor 32 via a transmission means 31 is connected to the flywheel 1.
10 and is connected to a connecting rod 96 via eccentric means. The connecting port/rod 96 reciprocates the ram 95 of the punch 94 within the slide 111.

A plate 122 is rotatably mounted on the main shaft and is linked to a second plate 124 and pivoted at its other end to a slide plate 112 carrying a mandrel. Chain or toothed belt 121
The rotation of the main shaft is controlled by the plates 122, 124.
A pair of wheels 12 attached to a pivot pin connecting the
7 and then a second chain or belt 123
is transmitted to a wheel 126 mounted on a pivot connecting plate 124 to slide plate 112. This wheel 126 is connected by eccentric means to a coupling arm 116 which actuates the index plate 115. The plate 115 supports the spring 12
pawl 11 engaged with index wheel 114 by 0
There are 7.

The reciprocating motion of the arm 116 causes the plate 115 to swing,
This allows the index wheel and mandrel 113 to
is rotated in stages with a constant angular displacement depending on the spacing of the teeth on the index wheel. This defines the movement of the strip past the punch 94 and defines the spacing of the slits punched in the strip. The angular spacing of the slots in the coil can be changed by replacing the index wheel with another number of teeth.

This type of connection allows constant indexing even when the mandrel, together with the slide plate, leaves the punch 94 as the diameter of the coil increases as winding progresses.

The pawl 117 can be moved away from the index wheel 114 by means of a piston-cylinder device 119 which actuates a lever arm carrying the pawl via a roller 118. This allows the mandrel to rotate independently from the punch 94 at the start and end of coil winding.

Once the field windings have been inserted and insulated, the core can be sealed.

The crimping process for closing the slots in the core is shown schematically in FIG. In this crimping process, the iron core 1
9 is supported on the base plate 18 by pins 20. A press bolster 21 carrying a cam plate 23 and a bottoming plate 22 is mounted facing the open slot in the core and is movable toward the core.

With the press in the open position, the closing fingers 24 arranged around the base plate and the iron core close the platform 2.
6 is inserted between the field coil 25 supported by it and the outer periphery of the iron core.

When the press is closed, the cam plate 23 contacts the upper end of the upright closing finger and rotates it inwardly about the axis 11, bringing the bottoming plate 22 into contact with the iron core and terminating the movement of the bolster 21. . As a result of this movement of the closing fingers, the tongues between the slots of the core are bent radially inward, substantially closing the gap at the top of the stator.

The width of the gap is determined by the angle β and has a significant impact on machine efficiency and desired slip reduction.

The platform 26 is then moved by a linkage system 15.16, which is moved by a piston-cylinder arrangement (not shown).
．． 17, whereby the closing finger emerges from the winding again guided by the pivot 11 in the guide slot 10 and returns to its initial position.

A machine for producing cores by winding strips according to the invention is shown schematically in FIGS. 7 and 8. In this machine, a punching and winding device is mounted on a frame 30 and configured to receive strip 22) supplied from a supply roll 36 supported on a stand 35. As previously mentioned, the strip first passes through a straightening device 52, then passes through a cutter 53, a first ear punch 54, a second slit punch device 55, 56, and is wound into the shape of a coil 38.

A transfer arm 39 transports the finished coil 38 to a first work station 47 where it is passed to a second transfer arm 40 and placed on a conveyor by actuation of a piston-cylinder arrangement 58. At station 47, the insulator 41 is inserted into the slot and the coil is then conveyed to a second station 48, comprising a wire head 42 and wire 43, for being subjected to field winding. The core is then conveyed to a second insulation station where insulation 44 for the air gap is inserted and finally (if required) via a holding station 50 to a slot closure station 51 where the core is automatically It is closed by a closing press 46. At this stage,
The core is removed from the conveyor and is actually transported again next to the first station. This cycle repeats automatically during machine operation.

This machine is fully automated and its operation can be electronically programmed.

[Brief explanation of the drawing]

1 shows a side view and a plan view of a rotor or stator with open slots and outwardly bent tongues; FIG. 2 shows a rotor or stator with closed slots (with the windings omitted); FIG. Figures 3 and 4 are corresponding drawings of other types of cores; Figure 5 shows a fully closed core with windings inserted; 6 is a plan view of the front and rear end regions of the punched strip; FIGS. 7 and 8 are side views and plan views of a complete installation for making an iron core according to the invention; FIG. 9 is a side view of the strip punching and winding device; FIG. 10 is a side view of the indexing device; and FIG. 11 is a side view of the press for closing the slots of the iron core. 2-- Core 3.5- Slot 9- Tongue 4.6.7- Air gap

Claims (1)

[Scope of Claims] 1. A helically wound coil consisting of a strip of electrical steel sheet, the strip having a transverse slit extending from one edge to partway through its width, and present in each winding layer of the coil. and are separated by tongues such that the slits cooperate to form a slot extending generally in the radial direction of the coil for accommodating an electrical winding, the electrical winding being received within the slot. and an electromagnetic core for an electric machine, wherein the tongues are bent inward toward the axis of the coil, thereby closing the upper end of the slot so as to substantially eliminate an air gap. 2. The electromagnetic core as claimed in claim 1, wherein each winding layer of the strip at the start and end of the coil is provided with a lug to prevent the coil from unraveling. 3. The electromagnetic core according to claim 1, wherein the space left in the slot is filled with a metal casting. 4. An electric machine having a rotor or stator according to claim 1. 5. A method of manufacturing an electromagnetic core for an electrical machine by winding a strip of electromagnetic steel sheet around a mandrel, the tip region of the strip having a predetermined length cut to a predetermined depth from one edge thereof. forming a narrow portion of the width of the strip, forming interlocking ears in the tip region of the strip and at a location corresponding to one turn around the mandrel, and at a location separated by another turn of the strip; To,
forming one opening for receiving said ear, and punching out in succession across the entire width of the strip transverse slits having an end at said first edge and separated by tongues of increasing width; Thereby, during successive winding, said slits cooperate with each other to form a slot generally radially across the coil for receiving a field winding, and said first edge is ablated by at least the depth of said slit. , forming a narrow region in the strip and cooperating ears near the end of the strip spaced one turn from the end of the strip to separate the wound portion of the strip from the supply coil; A method consisting of the steps of inserting and insulating the field winding, folding the tongues toward the inside of the coil, and closing the top of the slot, essentially eliminating the air gap. 6. A method as claimed in claim 5, including the step of filling the remaining space in the slot with a metal casting. 7. The method according to claim 6, wherein the metal is aluminum or an aluminum alloy. 8. The method of claim 5, wherein the tongues are bent outward before insertion of the field winding. 9. Apparatus for producing electromagnetic cores for electrical machines, comprising means for punching in a metal strip a series of transverse slits separated by tongues and means for winding said strip to form a coil. The punching and winding means are actuated by a common drive means and are connected via an indexing mechanism, whereby the slits are formed at predetermined angular intervals around the outer circumference of the coil, and each cooperate to form approximately 300 slits within the coil. forming a radial slot, further means for inserting a winding into the slot, and means for closing the slot by folding the tongue toward the inside of the coil to enclose the winding. A device comprising: 10. Means for feeding the strip from the supply roll to a punching and coil winding station, and transport means for delivering the wound core to a subsequent working station, the station having a slot for inserting the field winding into a slot in the coil. a slot closing station comprising means and means for closing an air gap in the slot, said punching and winding station comprising a cutter for reducing the width of the strip, punching ears and corresponding windows in the strip; a first punching means for punching a transverse slit in the strip for receiving a field winding; and a second punching means for punching a transverse slit in the strip for receiving a field winding; and a second punching means for winding the strip to form a coil, the slit punching means and the winding means being common. is driven by a drive mechanism and connected via an index mechanism, whereby slits can be formed at predetermined angular intervals on the outer periphery of the coil,
The slot closing means also includes a press for folding the tongues separating the slots into the coil, and the transport means is configured to sequentially transport the core to the next working station. Claim 9: An electromagnetic core is produced by processing an electromagnetic steel plate into a predetermined shape and rolling it up to form perforated slots.
Equipment described in Section. 11. The punching and winding station comprises means for folding the leading edge of the strip into contact with a mandrel, the mandrel comprising means for engaging the folded strip. equipment. 12. said slit punching means is driven from a shaft via eccentric means, said mandrel being mounted on a slidable plate and rotatable stepwise in one direction by an indexing mechanism; 11. A device as claimed in claim 10, which is connected to the shaft via a link that transmits the motion of the plate. 13. Claim 1 in which each step is determined by the number of teeth of an index wheel with replaceable teeth.
The device described in paragraph 2. 14. A press in which the slot closing means has a base supporting an iron core, a bolster movable towards the iron core and carrying a cam plate and a bottoming plate;
a closure finger disposed around said base and movable between upper and lower positions by means of a movable platform; in said upper position, the finger passes between the field winding and the outer circumference of the core, and by lowering the cam plate; 11. A device as claimed in claim 10, in which the fingers are arranged to pivot inwardly towards the axis of the winding, while in the lower position the fingers move away from the winding.