JPS62247746A - Electric motor with ironless armature - 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 The present invention relates to an electric motor with a ironless armature, and more particularly to a novel configuration of armature equipment and a method for manufacturing the same.

Ironless armatures for low voltage DC motors have been manufactured by winding conductive wire around a former to form a basket winding having many layers of wire windings.

Summary of the Invention According to FIG. 1 of the present invention, in a DC electric motor having an armature comprising a shaft and an armature coil provided on the shaft, the armature coil comprises a plurality of conductive strips, each strip is bent between its ends and extends back and forth in the axial direction of the shaft and circumferentially about the shaft, each end of the conductor strip being electrically connected to each end of the other conductor strip. A motor is provided.

At least some of the ends of the conductor strips may be electrically connected to segments of the commutator. Preferably, these segments are integrally formed at the ends of each strip.

The coil may be supported by a disk or radially extending web, which disk or web may have a cylindrical extension forming a base for the commutator.

In a preferred embodiment, the conductor strip is supported by a sheet of insulating material. These conductor strips are preferably
It forms a cylindrical body which is open at one end to receive a stationary core or magnet device forming the stator of the motor and whose other end is supported by the shaft of the motor.

According to another aspect of the invention, a method of manufacturing a ironless armature for an electric motor includes forming generally parallel rows of conductor strips, the wire rows being transverse to the length of the strips and A method characterized by bending at an acute angle, forming the series of folds into a cylinder with ends of the strip at one end, and electrically connecting these ends to form an armature coil. do.

The conductor strip is often formed into a sheet, which is folded about a line transverse to the length of the strip to align the ends of the strip, and the folded sheet is then rolled. A cylindrical body, in which the ends of the different conductors overlap each other and are connected to each other to form a winding. The strips may be folded around a sheet of insulating material that provides insulation between overlapping strips and forms a support for the rolled cylinder. Between circumferentially adjacent strips,
Air gaps may be provided to prevent short circuits between these adjacent strips.

In a particularly preferred form, the conductor strips are made of oxidizable metal and have a non-conductive oxidized surface to provide insulation between the overlapping strips. Very preferably the strip is made of anodized aluminum. If electrical connections are to be made by anodizing, the other portions of each strip may be masked to facilitate this electrical connection.

Very preferably, the armature coils are formed from rows of straight parallel conductor strips forming a parallelogram. The rows are folded midway along the strips parallel to the line of the ends of the strips and then rolled into cylinders. The angle of the parallelogram is preferably selected to bring the first end of each strip into facing contact with the second end of an adjacent strip, and each conductor is shaped like a cylinder with or without row spacing. Extends 360 degrees around the circumference (180 degrees on the outside and 180 degrees on the inside).

Preferably, some of the conductors each have an integrally formed commutator segment at one end, and the rows are folded and rolled before the segments are folded to the base of the commutator. good.

Preferably, however, the base is formed by folding the segments into the desired orientation and then insert molding them in place. When using insert molding techniques, plastic material may be flashed or flowed onto the cylindrical inner and/or outer surfaces of the forming coil.

Figure 1 shows a fractional horsepower PMDC motor 1 that utilizes a ironless armature. This motor 1 includes a steel outer casing 2, which is closed at one end 3,
The open end of this outer casing 2 is provided with a plastic end cap 4. This end cap and casing support bearings 5, 6 in which a motor shaft 7 is supported. A commutator 8 and an armature coil 9 are fixedly attached to the shaft 7, the shaft, commutator and coil forming an armature assembly.

Inside the casing 2, permanent magnets 10.11 are arranged around the armature coil 9. These magnets are mounted in a manner commonly known in the art. A brush gear 12 is provided within the end cap 4 and includes a pair of brush plates 13 and brushes 14, the brushes 14 being supported by segments 25 of the commutator 8.

Such end camp and brush gear assemblies are well known in the art and need not be described in detail here.

In more detail, the armature assembly embodying the invention includes a first cylindrical plastic base 16 fixed to shaft 7 for rotation therewith. and forms the base of the commutator 8. A plastic disc 18 is integrally formed with the base 16. A second hollow cylindrical plastic sheet 17 has a larger internal diameter than the first part 16 and is supported around the shaft 7 by a coil 9 which engages the disc part 18. This part 17 is the second
It supports and insulates the conductive strips 22 forming the armature coil 9, as will be explained in more detail below with reference to figures a and 2f. An immovable cylindrical core 19 is mounted on the end face 3 of the casing 2;
0, this core 19 projects into the annular space between the coil 9 and the shaft 7, but is spaced from both the coil 9 and the shaft 7.

FIG. 2a shows a blank 21 for forming the armature coil 9. FIG. The blank 21 is pressed from a copper plate and has a plurality of strips 22 of the same width and length. These strips 22 are labeled A to facilitate further explanation. These strips are of equal length and form a parallelogram, as can be seen in Figure 2a. To avoid cross-flow currents in the strips, each strip may be formed with a longitudinally extending strip 39. To be clear,
Only one such slit is shown in strip 22u. The first ends of these strips are formed with connecting portions 23 which project perpendicularly to each edge 26 of the parallelogram at an angle to the length of the strip. These parts 23 are connected by connecting strips 24 for ease of handling, each third strip being connected by a connecting strip 24! , - A commutator segment 25 is integrally formed at the end of the fence, etc. At the reflective or second end of the strip there is likewise a strip 28.
A connecting portion 27 is provided.

The blank is folded about line 29 midway between the ends of strip 22. The angle .theta. of the parallelogram is such that the end portion 27 on the strip overlaps the end portion 23 of the strisopulier to form an electrical connection between the strip and the strip. Material plastic sheet 17
Fold it around the center.

After folding, strips 24,28 are cut from the stock (FIG. 2C) and the stock is then rolled about an axis perpendicular to the fold line 29 so that the circumference is the width of the row along line 29. Form equal cylinders.

The material is rolled so that the end 27 is inside the cylinder. Strip 22 is slightly tapered toward end 27 so that the inner circumference of the forming cylinder is smaller than the outer circumference. After rolling, the end 23 on the strip faces the end 27 on the strip, and so on, the end 23 on the strip faces the end 27 of the striso pulley. Opposing ends 23,27 are brazed or welded together to form the strip into continuous conductive loops, each loop extending 360 degrees spirally around the forming cylinder, excluding the conductor width. , extending 180 degrees on the inner surface and 180 degrees on the outer surface.

bending the joint end 23.27 and associated segment 25 radially inward to create a further bend in the commutator segment 25 (2nd d) to provide a tab 32.40 for engaging the commutator base 16; Form. Commutator base 16 and disk 18 are formed by insert molding. This technique is well known in the art and, briefly, consists of supporting a folded and rolled coil in a forming tool and then injection molding a plastic base in place. Connect the tab 40 of the segment 25 to the recess 3 at the end of the commutator base 16.
0, and the tab 32 is received in the recess 33 between the base 16 and the collar 18 (FIG. 2f). When pressing the material, tabs 32 are also formed in the segments 25, and these tabs are connected by connecting strips 24 in the original material (Fig. 2a), but these portions are cut out from the material. Then, I was released. -r4 is supported by the end surface 38 and outer peripheral surface 36 of the disk 18.

For mechanical reasons, it may be preferable to omit the sheet 17 in order to deflect the conductors outward during rotation of the armature.

In this configuration, it is particularly preferred for the conductor 22 to be formed from anodized aluminum, the aluminum oxide layer being very strong and providing a good gap between the conductor strips, even in conditions where the strips rub against each other during flexure. This is thought to provide good insulation.

In another embodiment (FIG. 3), the commutator base collar 18 has a plurality of radially extending fan blades 35. These fan blades project between the connecting parts 23, 27 and form a centrifugal fan for creating a flow of cooling air in the vicinity of the commutator. For clarity, base 16
Only the disk 18 is shown in FIG.

Other coil shapes may also be used. The shape shown in FIGS. 2a to 1ζ to 2f is a bipolar winding. To form a four-pole winding, for example, the angle .theta. of the parallelogram seen in FIG. 2a is increased so that the strip-color folds over the strip ↓.

Each strip has 3 conductor spacings plus 3 as noted.
In case of 60 degrees or 4 pole winding, it is better to extend 180 degrees.

The number and cross-sectional size of strips 22 and the number of commutator segments 25 may be varied to provide different coil characteristics. Also, the commutator segment is a disk 18
, in which case the brush 14 is supported on this surface.

Such surface commutators are well known in the art.

[Brief explanation of drawings]

FIG. 1 shows a fractional horsepower permanent magnet direct current (P) embodying the present invention.
MDC) A cross-sectional view of the motor; Figure 2a shows the material for forming the ironless armature according to the invention; Figure 2b shows the material of Figure 2a folded before rolling; Figure 2c shows the second state when the connecting part of the strip is cut out.
Fig. 2d is a schematic cross-sectional view of the blank port of Fig. 2C after the commutator segments have been rolled and bent; Fig. 2e shows the material of Fig. 2c after the commutator base has been molded in place. Fig. 2d is an end view of the rolled material; Fig. 2f is a cross-sectional view taken along line n-n in Fig. 2e; Fig. 3 shows a modified example of the commutating section 1w of the armature in Fig. 1. FIG. 1... Fractional horsepower PWDC motor, 2...
・Outer casing, 4... End cap, 5.6... Bearing, 7... Motor shaft, 8... Commutator, 9... ... Coil, 10.11 ... Permanent magnet, 21 ... Material, 22 ... Strip, 25 ... Commutator segment. ] 6 Procedural amendment (formality) 3゜Relationship with the case of the person making the amendment Applicant 4, agent

Claims (1)

Claims: 1. A DC electric motor having an armature comprising a shaft and an armature coil disposed on the shaft, the armature coil comprising a plurality of conductive strips, each strip having a bent, and extending back and forth in the axial direction of the shaft and in the circumferential direction around the shaft,
A motor characterized in that each end of the conductor strip is electrically connected to each end of another conductor strip. 2. The motor according to claim 1, wherein the conductor strip extends in a spiral shape around the shaft. 3. The conductor strip forms a hollow cylinder around the shaft, a stationary iron core is positioned in the annular space between the cylinder and the shaft, and the outside of the cylinder forms the stator of the motor. 3. The motor according to claim 1, wherein the magnet device is positioned. 4. The conductor strip forms a hollow cylinder around the shaft, in the annular space between the cylinder and the shaft, a stationary magnet device forming the stator of the motor is positioned, and on the outside of the cylinder Claim 1 or 2, characterized in that the iron sleeve is positioned
Motors listed in section. 5. A motor according to any one of claims 1 to 4, characterized in that at least some of the ends of the conductor strips are electrically connected to commutator segments. 6. The motor of claim 5, wherein the commutator segments are each integrally formed at the end of each conductor strip. 7. A motor according to claim 5 or 6, characterized in that the commutator segments are supported on a cylindrical surface of a cylindrical commutator base provided axially on the shaft. 8. The motor according to any one of claims 1 to 7, characterized in that a plastic support is positioned at the bent portion of the conductor strip. 9. The motor according to any one of claims 1 to 8, wherein the conductor strip is made of anodized aluminum. 10. The conductive strip forms a hollow cylinder around the shaft, the cylinder being supported at one end of a collar on the shaft, the collar being provided with a plurality of radially extending fan blades. A motor according to any one of claims 1 to 9, characterized in that: 11. The motor according to any one of claims 1 to 10, wherein the conductor has a slit extending in the length direction. 12. A method for manufacturing a ironless armature for an electric motor, comprising forming generally parallel rows of conductor strips and bending the rows transversely to the length of the strips at an acute angle; A method characterized in that the rows are formed into a cylinder with strip ends at one end and the ends are electrically connected to form an armature coil. 13. A method according to claim 12, characterized in that the strip is straight. 14. Claims characterized in that the rows of linear strips form parallelograms, the rows are folded to align the ends of the strips, and then rolled to join these ends together. The method according to paragraph 13. 15. The method according to any one of claims 12 to 14, characterized in that the strip is pressed from a metal plate. 16. Forming a metallic material, the strips are connected to each other at their ends by means of connecting parts cut from the material after bending.
The method described in section. 17. When stamping, form armature segments at the ends of at least some of the strips, form the rows into cylinders, and then fold and support these segments at the armature base. 17. The method according to claim 15 or 16, characterized in that: 18. Claims 12 to 17, characterized in that the strip is made of anodized aluminum.
The method described in any of the paragraphs. 19. A method according to any one of claims 12 to 17, characterized in that the strip is made of copper. 20. Claim 1, characterized in that each strip is formed with a longitudinally extending slit between its ends.
The method according to Items 2 to 19. 21. A method according to claims 12 to 20, characterized in that a flexible support is positioned in the fold of the strip before forming the cylinder.