CA1080776A - Brush arrangement for multiple disc machines - Google Patents

Brush arrangement for multiple disc machines

Info

Publication number
CA1080776A
CA1080776A CA278,884A CA278884A CA1080776A CA 1080776 A CA1080776 A CA 1080776A CA 278884 A CA278884 A CA 278884A CA 1080776 A CA1080776 A CA 1080776A
Authority
CA
Canada
Prior art keywords
angle
brushes
degrees
composite
brush
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
CA278,884A
Other languages
French (fr)
Inventor
Eric Whiteley
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
General Electric Canada Co
Original Assignee
Canadian General Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Canadian General Electric Co Ltd filed Critical Canadian General Electric Co Ltd
Priority to CA278,884A priority Critical patent/CA1080776A/en
Application granted granted Critical
Publication of CA1080776A publication Critical patent/CA1080776A/en
Expired legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K23/00DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors
    • H02K23/54Disc armature motors or generators
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K13/00Structural associations of current collectors with motors or generators, e.g. brush mounting plates or connections to windings; Disposition of current collectors in motors or generators; Arrangements for improving commutation
    • H02K13/006Structural associations of commutators
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02KDYNAMO-ELECTRIC MACHINES
    • H02K23/00DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors
    • H02K23/26DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors characterised by the armature windings
    • H02K23/36DC commutator motors or generators having mechanical commutator; Universal AC/DC commutator motors characterised by the armature windings having two or more windings; having two or more commutators; having two or more stators

Abstract

ABSTRACT OF THE DISCLOSURE
Brush arrangement for a composite dynamoeletric machine comprised of two or more axial air-gap machines joined by a common shaft. Brush are located near the outer radial periphery of each of the axial air-gap machines, on at least one axial side of each machine. The brushes are inclined such that the outer extremities of the brushes are further removed from the common shaft than are the inner extremities of the brushes (that contact the commutator). The result of such a construction is that two or more axial air-gap machines, joined by a common shaft, can be mounted in close proximity to one another with a minimum of interference from the brushes or their associated assemblies.

Description

$~
, This invention relates to a composite cynamoelectric machine, and more particularly to the brush arrangement of a composite dynamoelectric machine comprised of two or more DC axial air-gap machines joined by a common shaft.
Axial air-gap machines, sometimes referred to as disc machines, have the characteristic, distinct from radial ; air-gap machines, of being much shorter in their axial dimension, for a given power rating. In many instances this means that the axial air-gap machine can be mounted directly onto the equipment with which it is being used, resulting in a quite compact overall arrangement; at least more compact than that which would result from the use of a radial air-gap machine.
In some cases, such as for example with a disc motor connected to drive a load, the motor may not have sufficient power. Drawing from the field of radial air-gap motors, obvious solutions to such a problem are either to ; use a motor with a higher power rating, or to use two 2Q motors to drive the same load.
Disc motors having permanent magnet rotors lend themselves quite nicely to the solution of employing two (or more) motors to drive the load. As disc motors are relatively short in their axial direction, two disc motors can be arranged on a common shaft, retaining the same radial dimensions as a single motor, and having an axial length that is not normally objectionable since it is only approxi-mately twice the short axial length of a single disc motor.
` Such an arrangement consists, in simplistic terms, of 3~ mechanically connecting the two motors together, and is not normally a complicated matter.
However, in the case of a wound disc rotor (such as in a DC motor) where electric current must be conducted to . ~

the rotor by brushes, the solution is not quite so simple.
Normal brush arrangements on DC disc motors either do not allow for a mounting of the motors that is sufficiently close in the axial direction as would be desirable for a compact assembly, or else, if a compact assembly is obtained, it does not allow for easy servicing of the brushes, and the resulting assembly has to be dismantled to allow the brushes to be changed or inspected. Since changing brushes .j.
is a common and regular aspect of DC motor maintenance, this presents a serious problem if a compact assembly of DC
disc motors is desired.
The present invention eliminates many of the problems associated with the brushes of a DC disc motor in such a compact assembly in the following manner. The rotor is provided with its commutator near its radial periphery and the brushes ~and their associated assemblies~ --are consequently located near the outer periphery of the stator. The brushes, rather than being aligned with their longitudinal axes parallel to the longitudinal axis of the shaft, have their axes inclined at an angle therefrom.
This angle can perhaps best be described as a compound ; angle comprised of a first angle, in a radial direction, away ~` from the longitudinal axis of the shaft, and a second angle, in a direction perpendicular to the direction of the first angle (i.e. a generally circumferential direction, as opposed ko a radial direction), with all brushes on the same side inclined alike. The result of such brush positioning is ;~ that the two or more DC disc motors can be mounted together, on a common shaft, with the stator of one motor touching the stator of another motor, and yet the brushes remain readily accessible so that the brushes can be removed and replaced wikh the com~ination of DC disc motors remaining intact.

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., In another way, the present inventi.on can be described as a composite dynamoelectric machine comprising - two or more axial air-gap machines joined by a common shaft;
. each of the axial air-gap machines is characterized by ~ brush.es located near th.e outer radial perlphery o~ the ~ axial air~gap machine, on at least one axial side, and inclined such th.at the outer extremities of the brushes are further removed from the shaft than are the inner extremities of the brushes.
:~. lQ In yet another way, the present invention can be described as a composite dynamoelectric machine comprising:
at least two axial air-gap motors joined by a common shaft;
. each axial air-gap motor has brushes located on both axial . sides, near the outer radial periphery; each brush protrudes ~ from an axial side of a motor at the same compound angle;
: the compound angle comprised of à~ a radial angle between the plane of the commutator surface and the axis of the - brush, the radial angle being greater than zero degrees and ,:
less than 8a degrees, and b~ a circumferential angle, between
2~ the axis of the brush and th.e plane of the commutator, the circumferential angle being greater than zero degrees and less than 80 degrees; the compound angle being of a magni.tude that the brush.es of the at lea~t two motors do not interfere ; with one another when th.e motors are combined to form th.e . composite dynamoelectric machine.
.. The invention will now be described in more detail w.ith reference to the accompanying drawings, wh.erein like parts in each of the several figures are identified by the same reference character, and wherein:
;- 3Q Figure 1 is a partial sectional view of two disc . motors incorporating the present invention;
::. Figure 2 is a partial sectional view of two disc ;'~ .
- 3 - ~ ~
-~ :
'`.. - . . . . , ~ , ~

motors connected to a load and incorporating the present . invention;
Figure 3A is a perspective view of a rotor showing .-~ its commutator segments and a reference co-ordinate system .- for describing the orientation of the brushes;
;. Figure 3B depicts a typical brush in relation to the co-ordinate system described in Figure 3A; -Figure 4 depicts a variation of the embodiment of Figure 2.
. 10 Referring now to Figure 1, there is depicted therein two DC disc motors 10 and 11 constructed according to .~ the present invention with their stators mechanically :~ connected to one another by suitable known means; for example, by bolts (.not shown). Motor 10 is identical to motor 11; the way they are arranged in the drawings, .~ one is the mirron image of the other. Since motors 10 and . 11 are identical they wi.ll be described simultaneously with li~e numerals being used to describe like parts in each motor.
Each motor 10 and 11 comprises a rotor 12 ~hich i5 mounted j,, , to a single shaft 13 that is common to both.motors 10 and 11.
Each rotor 12 is comprised of a hub portion 14 and an -l electrical winding portion 15 secured to the hub portion 14. One type of winding suitable for the invention is ~` described in Canadian Patent No. 990,773 to E. Whiteley, issued June 8, 1976. The winding comprises a number of coils bonded together or cast in a resinous material, for ~ example, an epoxy resin to provide a rigid discoidal rotor.
; An annular array of commutator segments 16 are provided on each side of the winding portion 15, adjacent the periphery ,. 3~ thereof, as shown, and these segments 16 form part of the ,. unitary structure. A band 17 of reinforcing material is ` bonded to the periphery of rotor 12. The band 17 is conveniently ..''' !' . ' ; ~ 4 ~
~ ~ . . . : ,, : . . . :
.':'' ' , ' ': '.. ,, . . ,~ :

of la~ers of tape having glass fibers extending around the peripher~ and bonded thereto.
A stator 18 has two generally disc-like housing members 19 and 20 which include respectively covers 21 and 22 for the brush gear. The two housing members 19 and 2Q
are fastened together by bolts 23 and the members 20 include bearings 34 to provide for rotation of the shaft 13 within the stators 13. The brush mounted in housing member 21 can be seen in motor 10 and is referenced by the numeral 24.
The brush mounted in housing member 22 can be seen in motor 11 and is referenced by t~e numeral 25. Mounting members 26 and 27, preferably of mild steel, are secured or fastened to housing members 19 and 20 respectively. Permanent magnets 28 and 29 are mounted opposite one another to mounting members 26 and 27. The permanent magnets 28 and 29 form the poles of the machine and any number of magnets can be used for each pole. The motor field extends between the poles; that is, it extends between magnets 28 and 29 ~of the same motor), and through winding 15 of that same motor. It will be seen that the field is su~stantially parallel to the axis of shaft 13 and thus the motors 10 and 11 are axial air-gap motors. The mounting members 26 and 27 provide a magnetic path for the magnetic field circuit.
As is readily apparent from Figure 1, brushes 24 ,I
`~ and 25 are inclined away from the shaft 13 (in a radial direction) so that the outer extremities of the brushes 24 and 25 are farther from shaft 13 than are their inner extremities which contact commutator segments 16. The brushes 24 and 25 are also inclined in a second direction (a circumfer4ntial direction) which is more clearly illustrated `; in Figures 3A and 3B; in E'igure 1, however, it should be ` noted that ~rush 25 of motor 11 is inclined toward the viewer ' ::

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, . .

and brush 24 (enclosed by cover 21) of motor 11 is inclined away from the viewer. Since motor 10 is identical to motor 11, but is situated in Figure 1 so as to be the mirror image of motor 11, brush 24 of motor 10 is inclined toward the viewer and brush 25 (enclosed by cover 22) of motor 10 is inclined awa~ from the viewer. It should be noted that brushes 24 and 25 are only two of several such devices located around the peripheries of the stators 18 of the motors 10 and 11. All the brushes 24 located on one side of the stator 18 are all inclined alike; and all the brushes 25 on the other side of the stator 18 are all inclined alike.
The inclination of the brushes 24 and 25 can also be described in a somewhat more exacting manner, with reference to Figures 3A and 3B, as follows. Figure 3A
depicts, in simplified form, the rotor 12 of one of the motors .. ..
lQ, 11 and the shaft 13. Shown on the rotor 12 are the commutator segments 16. A co-ordinate system is shown in connection with one of the commutator segments 16. One 2Q point, approximately the centre o~ the exterior surface of one commutator segment 16, is chosen as the origin 0 for the co-ordina-te system. The plane C-0-D is the plane of the commutator surface, where the line 0-D is a radius from the shaft 13 and the line 0-C is an arc with its centre of curvature at shaft 13. The line 0-A is a perpendicular to the plane of the commutator surface (i.e. perpendicular , to khe plane C-0-D) and is parallel to the longitudinal axis of shaft 13. The line 0-B represents the longitudinal axis of a brush 24, 25. The line 0-CC is a tangent to the line 0-C at the origin 0, in the plane C-0-D, such that the lines 0-CC, 0-D, and 0-A now form an orthogonal co-ordinate system. As a consequence, the planes A-0-D, ; .

.
, .
::: , . . : ~ .

A-~CC, and D-0-CC are all mutually orthogonal to one another.
Now, referring to E'iguxe 3s, a representative brush 24 is shown superposed upon the orthogonal co-ordinate system described above, with reference to Figure 3A. Brush 24 has a longitudinal axis 39 which passes through the origin 0 and is also referenced as line s-o. It can be seen from Figure 3B that when the brush axis B-0 is referred to the aforementioned planes, there will be a corresponding projection of the brush axis on both plane A-0-CC, and plane lQ A-0-D. These projected images of the brush axis B-0 on the planes define the angles ~ and ~ as shown in Figure 3B.
The direction 0 to D is described as being the "radial"
direction and consequently angle ~ is referred to as the radial angle between the brush axis 0-s and the commutator plane D-0-CC. '~he direction 0 to CC is described as being the "circumferential" direction and consequently angle is referred to as the circumferential angle between the brush axis 0-B and the commutator plane D-0-CC.
` While, from a theoretical point of view, the angles ~ and ~ can range from zero to 90 degrees, it has been found that an upper limit of 80 degrees for angle 0 is a more practical limit (to ensure stability in the contact between ~; brush and commutator). The practical limits on angle g will depend partly on the exact design of the machines, but the upper limit will have to be less than 90 degrees in order to provide e~sy access to the ~rushes in the completed composite dynamoelectric machine. The lower practical limit for both angles ~ and 0 will be greater than zero degrees. The circumferential angle 0 is preferably between 65 and 75 degrees; the radial angle ~ is preferably approxi-mately 60 degrees.
The result of such a construction can be seen .'~ .

,.

, ~ . , .. . . .

at the juxtaposition of motors 10 and 11 near the brush covers 21 (in Figure 1). It can be seen that brush 24 (of motor 10) is inclined both away from shaft 13 and towards the viewer. In contrast, brush 24 (enclosed in cover 21) of motor 11 is inclined both away from shaft 13 and away from the viewer. This enables housing members 19 of motors 10 and 11 to come into touching contact with one another without any interference from the brushes 24 of the two motors. At the same time, all brushes 24 are maintained readily accessible from exterior both motors 10 and 11 . .
; without dismantling of the motors 10 and 11.
Figure 2 depicts two motors 30 and 31 that are l very similar to motors 10 and 11 of Figure 1. The primary i difference between the motors of the two Figures is that ,r~ motors 30 and 31 of Figure 2 do not have any bearings of their own. The load 32 has an "overhung" shaft 33 supported l by bearings 35 (of which only one is shown in the Fig.~.
i The stator of motor 30 is attached by mechanical means such '`~ as bolts (not shown) directly to the frame of load 32 and the rotors 12 of motors 30 and 31 are attached directly to the shaft 33 of the load 32. In such an arrangement, separate ~ bearings for motors 30 and 31 are not required and hence can `~¦ be eliminated. Additionally, a plate 36 is used to seal the ;~ opening in housing member 20 to prevent any contaminants from i entering the motors 30 and 3I.
: !
; Figure 4 depicts a further variation of the embodiment of Figure 2. In Figure 4 it is readily apparent that the load 32 has a somewhat longer overhung shaft 38 and , a ~earing 37 has been included in hous-ing member 2~ of the outermost motor (i.e. motor 31~ to provide additional support for the shaft. The decision of which embodiment (depicted in ~;, Figures 1, 2 and 4) to emplo~ will depend upon the specific .
. ~ -- .
: ' ' application and it is not deemed necessary to comment upon the criterion involved in such a decision, as it is beyond . the scope of the present specification.
Obvious variations to this invention would include ma]cing housing member 19 identical to housing member 20.
This would result in a standardization of components for the :: motor combination, and the embodiment of Figure 1 would be , realized by using bearings 34 only in combination with ., the outer housing members of the motor combination, and not lQ with the inner housing members. This variation is also equally applicable to the embodiments of Figures 2 and 4.

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Claims (10)

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as follows:
1. A composite dynamoelectric machine comprising two or more axial air-gap machines joined by a common shaft;
each of the said axial air-gap machines is characterized by brushes located near the outer radial periphery of said axial air-gap machine, on at least one axial side, and inclined such that the outer extremities of the brushes are further removed from said shaft than are the inner extremities of said brushes.
2. The composite dynamoelectric machine of claim 1 wherein two direct current motors are employed and said brushes are located on both axial sides of both said motors.
3. The composite dynamoelectric machine of claim 1 or 2 wherein each brush protrudes from an axial side of a motor at the same compound angle; said compound angle com-prised of a) a radial angle between the plane of the commutator surface and the axis of the brush, said radial angle being greater than zero degrees and less than 80 degrees, and b) a circumferential angle, between the axis of the brush and the plane of the commutator surface, said circumferential angle being greater than zero degrees and less than 80 degrees,
4. A composite dynamoelectric machine comprising:
at least two axial air-gap motors joined by a common shaft;
each said axial air-gap motor has brushes located on both axial sides, near the outer radial periphery; each brush protrudes from an axial side of a motor at the same compound angle;
said compound angle comprised of a) a radial angle between the plane of the commutator surface and the axis of the brush, said radial angle being greater than zero degrees and less than 80 degrees, and by a circumferential angle, between the axis of the brush and the plane of the commutator surface, said circumferential angle being greater than zero degrees and less than 80 degrees; said compound angle being of a magnitude that the brushes of said at least two motors do not interfere with one another when said motors are combined to form said composite dynamoelectric machine.
5. The composite dynamoelectric machine of claim wherein two direct current motors are employed.
6. The composite dynamoelectric machine of claim 5 wherein the outer extremities of said brushes are further removed from said shaft than are the inner extremities of said brushes that contact the commutators.
7. The composite dynamoelectric machine of claim 4, 5 or 6 wherein said radial angle is approximately 60 degrees, and wherein said circumferential angle is approximately between 65 and 75 degrees,
8. A composite dynamoelectric machine in combination with an associated load, said combination comprising: a load having a frame and an overhung shaft at one end thereof; said composite dynamoelectric machine securely fastened to said frame of said load so as to have the overhung portion of said overhung shaft serving as a common shaft for said composite dynamoelectric machine; said composite dynamoelectric machine comprising at least two axial air-gap motors having their rotors secured to said shaft for rotation therewith; each said axial air-gap motor having brushes located on both axial sides, near the outer radial periphery; said brushes having their outer extremities inclined away from said shaft so as not to interfere with the brushes of an adjacent motor.
9. The combination of claim 8 wherein each brush protrudes from an axial side of a motor at the same compound angle; said compound angle comprised of a) a radial angle between the plane of the commutator surface and the axis of the brush, said radial angle being greater than zero degrees and less than 80 degrees, and b) a circumferential angle,
Claim 9 continued:
between the axis of the brush and the plane of the commutator surface, said circumferential angle being greater than zero degrees and less than 80 degrees.
10. The combination of claim 9 wherein said radial angle is approximately 60 degrees and said circumferential angle is approximately between 65 and 75 degrees.
CA278,884A 1977-05-20 1977-05-20 Brush arrangement for multiple disc machines Expired CA1080776A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CA278,884A CA1080776A (en) 1977-05-20 1977-05-20 Brush arrangement for multiple disc machines

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CA278,884A CA1080776A (en) 1977-05-20 1977-05-20 Brush arrangement for multiple disc machines

Publications (1)

Publication Number Publication Date
CA1080776A true CA1080776A (en) 1980-07-01

Family

ID=4108704

Family Applications (1)

Application Number Title Priority Date Filing Date
CA278,884A Expired CA1080776A (en) 1977-05-20 1977-05-20 Brush arrangement for multiple disc machines

Country Status (1)

Country Link
CA (1) CA1080776A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0123347A1 (en) * 1983-04-15 1984-10-31 Mavilor Systèmes S.A. Collectorless direct current motor with electronic commutation
EP0486746A1 (en) * 1990-11-20 1992-05-27 Kollmorgen Corporation Flat motor of reduced length

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0123347A1 (en) * 1983-04-15 1984-10-31 Mavilor Systèmes S.A. Collectorless direct current motor with electronic commutation
EP0486746A1 (en) * 1990-11-20 1992-05-27 Kollmorgen Corporation Flat motor of reduced length

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