EP1634362A1 - Moteur lineaire sans balai a courant continu et a noyau de fer presentant une force de detente reduite - Google Patents

Moteur lineaire sans balai a courant continu et a noyau de fer presentant une force de detente reduite

Info

Publication number
EP1634362A1
EP1634362A1 EP04754235A EP04754235A EP1634362A1 EP 1634362 A1 EP1634362 A1 EP 1634362A1 EP 04754235 A EP04754235 A EP 04754235A EP 04754235 A EP04754235 A EP 04754235A EP 1634362 A1 EP1634362 A1 EP 1634362A1
Authority
EP
European Patent Office
Prior art keywords
stack
teeth
motion
motor
assembly
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.)
Withdrawn
Application number
EP04754235A
Other languages
German (de)
English (en)
Inventor
Mikhail Godkin
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.)
BEI Sensors and Systems Co LLC
Original Assignee
BEI Sensors and Systems Co LLC
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 BEI Sensors and Systems Co LLC filed Critical BEI Sensors and Systems Co LLC
Publication of EP1634362A1 publication Critical patent/EP1634362A1/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
    • H02K41/02—Linear motors; Sectional motors
    • H02K41/03—Synchronous motors; Motors moving step by step; Reluctance motors
    • H02K41/031—Synchronous motors; Motors moving step by step; Reluctance motors of the permanent magnet type
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
    • H02K41/02—Linear motors; Sectional motors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K41/00—Propulsion systems in which a rigid body is moved along a path due to dynamo-electric interaction between the body and a magnetic field travelling along the path
    • H02K41/02—Linear motors; Sectional motors
    • H02K41/035—DC motors; Unipolar motors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/12—Stationary parts of the magnetic circuit
    • H02K1/16—Stator cores with slots for windings
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K1/00—Details of the magnetic circuit
    • H02K1/06—Details of the magnetic circuit characterised by the shape, form or construction
    • H02K1/12—Stationary parts of the magnetic circuit
    • H02K1/18—Means for mounting or fastening magnetic stationary parts on to, or to, the stator structures
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K2213/00—Specific aspects, not otherwise provided for and not covered by codes H02K2201/00 - H02K2211/00
    • H02K2213/03—Machines characterised by numerical values, ranges, mathematical expressions or similar information
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K3/00—Details of windings
    • H02K3/46—Fastening of windings on the stator or rotor structure
    • H02K3/48—Fastening of windings on the stator or rotor structure in slots
    • H02K3/487—Slot-closing devices

Definitions

  • the present disclosure is directed generally to linear brushless DC motors, and in particular to an ironcore linear brushless DC motor with reduced detent force.
  • a typical linear brushless motor of a rectangular configuration consists essentially of two parts: an armature assembly and a field assembly separated from each other by a small air gap.
  • An armature assembly in turn, consists of a stack 10 of laminations with a three-phase winding positioned in its slots 12. Such a stack 10 is shown in Fig. 1.
  • a field assembly is a rectangular soft magnetic plate with the rectangular magnets of alternating polarities facing the air gap.
  • Slot openings 14 for the armature assembly are normally selected to be as small as possible to minimize cogging forces.
  • Fig. 2 shows typical slot openings 14.
  • the top surface 16 of the stack 10 should have drilled and tapped holes.
  • locking wedges 18 with mounting holes are provided, as shown in Fig. 1. Once the laminations are punched with the slots 20 for these locking wedges 18, the distance between locking wedges becomes fixed and cannot be changed without re-tooling the punch for the laminations.
  • a linear brushless DC motor that incorporates such a stack structure, which can substantially reduce detent force, through the shaping of the end teeth of the stack, preferably where the end teeth are formed as wedges.
  • a stack design for use in an armature assembly, including a plurality of windings, wherein the stack comprises a base portion, a plurality of teeth extending from the base portion and about which the windings can be positioned, and wherein the plurality of teeth are spaced apart from each other at a predetermined pitch, t ⁇ , and including a first end tooth positioned at one end of the stack in a direction of motion and a second end tooth positioned at another end of the stack in the direction of motion; and wherein the first and second end teeth are wedge shaped, and further wherein the stack has a uniform length along a direction of motion approximately equal to a non-integer multiple of the number of poles under the armature, for example, a length of (Np + Vz) x tp, where
  • Np corresponds to a number of poles underneath the armature
  • t p corresponds to a distance between centers of two adjacent magnets of opposite polarity in a field assembly.
  • ⁇ is slightly less than tp, for example, a ratio of ⁇ to tp may be 7:8.
  • the end teeth may have a right- triangular cross section in a plane along the direction of motion and parallel to the base portion, so as to have a width which is substantially zero at its apex, and at a maximum, Wm 3x , along its base.
  • Wmax may be approximately equal to tp.
  • the area of the right-triangular cross section of the end teeth may be approximately equal to the area of the cross sections of interior teeth of the stack.
  • Fig. 1 is an illustration of a typical stack assembly in the prior art.
  • Fig. 2 is an illustration of a portion of a typical stack assembly in the prior art.
  • Fig. 3 is an illustration of a portion of a stack assembly configuration, which facilitates winding of coils while reducing cogging forces.
  • Fig. 4 is an illustration of a portion of a stack assembly in which the slot openings of Fig. 3 have been plugged in accordance with a configuration which facilitates winding of coils while reducing cogging forces.
  • Figs. 5A and 5B illustrate a stack assembly including a mounting bracket in accordance with a configuration that provides a simplified yet flexible attachment structure, and also illustrate the wedges of the embodiment of Fig. 4.
  • Fig. 6 is an enlarged view of a portion of a tooth and of a wedge in the stack of a configuration, which facilitates winding of coils while reducing cogging forces.
  • Fig. 7 is a perspective view of a stack assembly in accordance with an embodiment of the present invention.
  • Fig. 8 is a plan view of the stack assembly embodiment of Fig. 7.
  • Fig. 9 is a perspective view of an armature assembly employing the stack assembly of Fig. 7.
  • Fig. 10 illustrates a preferred relationship between the dimensions of the stack assembly and the magnets of a field assembly in accordance with a preferred embodiment of the present invention.
  • Figs. 11 A, 11 B and 11 C illustrate three positions of the stack relative to the field assembly in accordance with a preferred embodiment of the present invention. Detailed Description of the Disclosed Embodiments
  • Fig. 3 a portion of the stack assembly 100 of a configuration, which facilitates winding of coils while reducing cogging forces, is illustrated.
  • the teeth 102 of the stack extend outwardly from base portion 106.
  • the width of the slots 104 separating teeth 102 is substantially the same from bottom (at the base portion 106) to top portion 108 (free ends of the teeth). This is in contrast to tooth designs of previous stack assemblies, for example in Fig. 2, in which the top end of the teeth flares outwardly to narrow the slot opening 14 between teeth.
  • the top portion 108 of each tooth 102 has two additional notches 110, as can be seen in Fig. 3, to accommodate magnetic wedges 112, as illustrated in Fig. 4.
  • the purpose of these magnetic wedges 112 is to minimize the difference in the air gap reluctance along the centerline 114 of a tooth 102 and the centerline 116 of a slot 104. The smaller this difference is, the lower the cogging force will be.
  • a composite armature assembly includes the stack assembly 100 with the winding (not shown), magnetic wedges 112 in the slots 104, and a mounting bracket 120 made from soft magnetic material.
  • mounting bracket 120 has a dimension along the longitudinal axis of stack assembly 100 which is greater than that of mounting bracket 120, and has a thickness which is preferably greater than the thickness of base portion 106 of stack assembly 100.
  • the width dimension (transverse to the longitudinal axis of stack assembly 100, is also preferably greater than the width dimension of the stack.
  • a dovetail arrangement is employed which allows a precise fit between the stack assembly 100 and the mounting bracket 120.
  • FIG. 5B This preferred dovetail arrangement is further illustrated in Fig. 5B.
  • the base portion 106 has a surface which is angled outwardly in a direction toward the outer surface of base portion 106.
  • the ends of mounting bracket 120 have portions 122 and 124 which extend downwardly in the direction of teeth 102, and which have inner surfaces which are shaped to be compliments of the ends of base portion 106.
  • the inner surfaces of portions 122 and 124 flare inwardly so that portions 122 and 124 capture the outwardly flared ends of base portion 106. While a dovetail arrangement has been disclosed as a preferred arrangement, it is to be understood that other arrangements can be used to position mounting bracket 120 on base portion 106 of stack assembly 100 within the spirit of the disclosed embodiments.
  • mounting bracket of the disclosed embodiment there is no need for retooling of a lamination punch in order to accommodate changes in distance between mounting holes, and mounting hole configurations can be changed by replacing a single bracket instead of the multiple wedges of the prior art.
  • Fig. 6 is an expanded view of the relationship between the solid or laminated magnetic wedges 112 and the notches 110, which are formed in the top portion 108 of teeth 102 of the armature stack assembly 100 of the disclosed embodiment.
  • wedge 112 is formed to have a trapezoidal cross section, with the length dimension for the wedge surface 126 which faces inwardly toward the windings (not shown) being larger than the length dimension for the surface which faces outwardly away from the windings.
  • Notch 110 which is cut in top portion 108 of each tooth 102, is shaped to compliment the dimensions of wedge 112, so that a dovetail fit is achieved between notch 110 and wedge 112.
  • wedge 112 is sized so that the surface, which faces outwardly, away from the windings, is substantially flush with the outwardly facing surface of tooth 102 when wedge 112 is in place in notch 110.
  • an embodiment of the present invention which provides an ironcore linear brushless DC motor with reduced detent force.
  • the embodiment includes a feature, which substantially reduces detent force of the linear motor by shaping the end teeth 152, 154 of the stack 150 as wedges.
  • the end teeth may have a right-triangular cross section in a plane parallel to mounting bracket 156, with the hypotenuse of the cross section facing outwardly from the ends of the stack 150.
  • the maximum width, W max , of wedge-shaped end- teeth 152 and 154, in the direction of motion, may be approximately equal to the center-to-center spacing, t p , between magnets 164 (Fig. 10). Further, the minimum width, W mi n, of wedge-shaped end-teeth 152 and 154, in the direction of motion, is substantially zero (Fig. 8). Also, it is to be noted that at the point of maximum width, Wm a x, the wedge-shaped end teeth 152 and 154 each extend outwardly beyond the mounting bracket 156, for example by about W max /3.
  • FIG. 7 Another feature of the embodiment of Figs. 7, 8, 9, 10, 11 A, 11 B, and 11 C is that the outward faces of wedge-shaped end teeth 152 and 154 do not extend to the full depth as the faces of internal teeth 158. From Fig. 7 it can be seen that a step 160, having a thickness x, is provided between the mounting bracket and the outward face of wedge-shaped end teeth 152 and 154.
  • Fig. 9 illustrates an armature assembly, which incorporates the stack 150 of Figs. 7 and 8. Windings 153 are shown surrounding every other internal tooth 158. Also shown are end brackets 155 and 157, which may be fastened to ends of mounting bracket 156, underlying wedge-shaped end teeth 152 and 154, respectively. Mounting bracket 156 can be seen to have dovetail type coupling structures at its ends and interior. The beveling of the dovetail type structures at the ends of mounting bracket 156 can be seen in greater detail in Fig. 7. As illustrated in Fig.
  • the total length of the stack 150 along the direction of motion remains constant and may be equal to (Np + Vz) x tp
  • N p is the number of poles underneath the stack 150 (for example, 8,10, 12 etc.)
  • tp is the pole pitch, which is the distance between the centers of two adjacent magnets 164 of opposite polarity in a field assembly 162 with which the stack 150 is used.
  • the pole pitch, tp may be 16 mm
  • the number of poles underneath the stack, Np may equal eleven (11 ).
  • the stack 150 may cover approximately the same number of magnets (in this case - 11.5) regardless of the position of the stack relative to the field (magnet) assembly.
  • the width of internal teeth 158 of stack 150 may be approximately 8.2 mm, and the center to center spacing, fy, between internal teeth
  • the stack 150 has the same "length" (in the direction of motion) at any point transverse to the direction of motion. This is illustrated in the top portion of Fig. 10 in which the same dimension 11.5x tp is indicated along the top, middle and bottom dimensions of stack 150.
  • a principal feature of the disclosed configuration of the stack 150 relative to the field assembly 162 is that the stack surface "covers" the same (on average) number of magnets, and the reluctance does not substantially change as a function of stack position.
  • the number of slots (teeth) per pole is close to one (12 slots vs. 11 poles). This means that the pole pitch, tp, is almost the same as the tooth pitch, ty.
  • a stack of laminations with all straight teeth would have covered an integer number of pole pitches. (In this case, eleven.)
  • the configuration of the disclosed embodiment covers a fractional number of pole pitches (11.5 in this case).
  • the length of any longitudinal cross-section of the stack is equal to 11.5 pole pitches.
  • the number of teeth in the stack, including end teeth equals Np + 1.
  • Figs. 11 A, 11 B, and 11 C illustrates three positions of the stack 150 relative to the field (magnet) assembly 162, showing that the "coverage" of the stack surface with respect to the magnets 164 is the same for each position.
  • the footprint of stack 150 relative to field assembly 162 at any longitudinal section along the direction of motion can be seen to cover approximately 11.5 magnets 164.
  • the left side of the footprint of stack 150 begins at the center of a magnet 164, and extends to the right (a direction of motion) over eleven entire magnets.
  • the middle of the footprint begins at the left edge of a magnet and extends to the right over ten and one-half additional magnets.
  • Figs. 11 A, 11 B and 11 C it can be seen from Figs. 11 A, 11 B and 11 C, that for the illustrated embodiment, the bases of the wedge shapes of the end teeth 152 and 154 of stack 150, have a length approximately equal to the pole pitch, t p . It can also be seen that in the embodiment illustrated, the tooth pitch, t ⁇ , is less than t p , but greater than at least 0.75 tp.
  • a further feature illustrated in Figs. 11 A, 11 B and 11 C is that for the various positions of stack 150 relative to the magnets 164 in the range of motion of the linear brushless DC motor, there will be at least one magnet that is covered by no more than one of the teeth of stack.
  • the detent force due to a finite length of the stack in the direction of motion would be zero, and the detent force may be eliminated.
  • the detent force is significantly reduced and is almost suppressed, and movement has been found to be very smooth.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • Linear Motors (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Abstract

L'invention concerne un moteur linéaire sans balai à courant continu présentant une force de détente réduite au moyen d'une pile (150) pourvue de dents d'extrémité (152, 154) en forme de cales. Ledit moteur présente une longueur, dans le sens du mouvement, quasiment égale à un pas de pôle (Np+1/2), dans lequel Np est égal au nombre de pôles couverts par l'armature du moteur sans balai à courant continu, et le pas de pôle est égal à la distance entre les centres de deux aimants adjacents (164) d'une pluralité opposée dans un ensemble champ (162) dudit moteur.
EP04754235A 2003-06-06 2004-06-02 Moteur lineaire sans balai a courant continu et a noyau de fer presentant une force de detente reduite Withdrawn EP1634362A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US47674103P 2003-06-06 2003-06-06
PCT/US2004/017582 WO2004112224A1 (fr) 2003-06-06 2004-06-02 Moteur lineaire sans balai a courant continu et a noyau de fer presentant une force de detente reduite

Publications (1)

Publication Number Publication Date
EP1634362A1 true EP1634362A1 (fr) 2006-03-15

Family

ID=33551636

Family Applications (1)

Application Number Title Priority Date Filing Date
EP04754235A Withdrawn EP1634362A1 (fr) 2003-06-06 2004-06-02 Moteur lineaire sans balai a courant continu et a noyau de fer presentant une force de detente reduite

Country Status (5)

Country Link
EP (1) EP1634362A1 (fr)
JP (1) JP2006527576A (fr)
KR (1) KR20060022260A (fr)
CN (1) CN1799180A (fr)
WO (1) WO2004112224A1 (fr)

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102005004380B4 (de) * 2005-01-31 2012-02-02 Siemens Ag Linearmotor mit Kraftwelligkeitsausgleich
JP5106833B2 (ja) * 2006-11-15 2012-12-26 ヤマハ発動機株式会社 リニアモータおよび一軸アクチュエータ
JP5365171B2 (ja) * 2007-11-30 2013-12-11 シンフォニアテクノロジー株式会社 モータ
JP5477126B2 (ja) * 2010-04-07 2014-04-23 日立金属株式会社 リニアモータ
CN104467355B (zh) * 2014-11-26 2017-04-12 沈阳工业大学 正交结构边齿的低磁阻力波动永磁直线电机
CN104779773B (zh) * 2015-03-24 2017-10-31 沈阳工业大学 一种v‑型结构低磁阻力波动永磁直线电机
US10686355B2 (en) * 2016-07-15 2020-06-16 Magnemotion, Inc. Transport system puck assembly
CN110855119B (zh) * 2019-11-11 2021-05-18 华中科技大学 一种分数极两相游标永磁直线电机

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2177428A1 (es) * 2000-11-20 2002-12-01 Inst Cientifico Tecnol Navarra Motor lineal con eliminacion de fuerzas de reluctancia.

Family Cites Families (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6447262A (en) * 1987-08-17 1989-02-21 Shinko Electric Co Ltd Linear dc brushless motor
JPS6447261A (en) * 1987-08-17 1989-02-21 Shinko Electric Co Ltd Linear dc brushless motor
US5032746A (en) * 1988-03-22 1991-07-16 Sharp Kabushiki Kaisha Linear motor with driving device
JPH01315250A (ja) * 1988-03-22 1989-12-20 Sharp Corp リニアモータ及びリニアモータを使用した直線駆動装置
DE19528043C1 (de) * 1995-07-31 1996-10-24 Krauss Maffei Ag Synchron-Linearmotor
JPH1047262A (ja) * 1996-07-29 1998-02-17 Mitsubishi Motors Corp オイルポンプ及びその組付方法
JPH1047261A (ja) * 1996-07-30 1998-02-17 Toyoda Mach Works Ltd ベーンポンプ
JP3817967B2 (ja) * 1999-05-18 2006-09-06 株式会社安川電機 リニアモータ
JP2002034230A (ja) * 2000-07-18 2002-01-31 Yaskawa Electric Corp リニアモータの電機子
JP4556229B2 (ja) * 2000-11-21 2010-10-06 株式会社安川電機 コアレスリニアモータ
JP4194367B2 (ja) * 2001-04-09 2008-12-10 カスタム・センサーズ・アンド・テクノロジーズ・インク 鉄心複合アーマチャ組立を有するリニア・ブラシレス・ｄｃモータ

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
ES2177428A1 (es) * 2000-11-20 2002-12-01 Inst Cientifico Tecnol Navarra Motor lineal con eliminacion de fuerzas de reluctancia.

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO2004112224A1 *

Also Published As

Publication number Publication date
WO2004112224A1 (fr) 2004-12-23
CN1799180A (zh) 2006-07-05
KR20060022260A (ko) 2006-03-09
JP2006527576A (ja) 2006-11-30

Similar Documents

Publication Publication Date Title
US8274182B2 (en) Linear motor including extended tooth tips
US7145271B2 (en) High performance linear motor and magnet assembly therefor
US6949846B2 (en) Linear motor with reduced cogging force
US20080296990A1 (en) Arrangement of Rotor Laminations of a Permanently Excited Electrical Machine
US7362012B2 (en) Ironcore linear brushless DC motor with reduced detent force
EP1261103A1 (fr) Moteur à courant continu sans balais
US20020070612A1 (en) Linear motor
JPWO2019058643A1 (ja) インシュレータ及びそれを備えたステータ、モータ
WO2004112224A1 (fr) Moteur lineaire sans balai a courant continu et a noyau de fer presentant une force de detente reduite
JP3817883B2 (ja) リニアモータ
US6919660B2 (en) Linear brushless DC motor with ironcore composite armature assembly
JPH11113198A (ja) 永久磁石電動機
EP0414507B1 (fr) Perfectionnement aux machines électriques à réluctance
US11955864B2 (en) Linear motor
JP4522192B2 (ja) リニアモータ
JP4110335B2 (ja) リニアモータ
JP4400283B2 (ja) アキシャルギャップ型回転電機のステータティース構造
KR20230084595A (ko) 전동기
JP2001145327A (ja) リニアモータの電機子
RU13522U1 (ru) Пазовая часть электродвигателя
US11843284B2 (en) Rotor of rotary electric machine and rotary electric machine
WO2024100907A1 (fr) Moteur linéaire
JP7005741B2 (ja) 永久磁石型モータ

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20060105

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR

AX Request for extension of the european patent

Extension state: AL HR LT LV MK

17Q First examination report despatched

Effective date: 20070823

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20130413