WO2025008166A1 - A stator core structure for a tubular linear electric machine - Google Patents

A stator core structure for a tubular linear electric machine Download PDF

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Publication number
WO2025008166A1
WO2025008166A1 PCT/EP2024/066748 EP2024066748W WO2025008166A1 WO 2025008166 A1 WO2025008166 A1 WO 2025008166A1 EP 2024066748 W EP2024066748 W EP 2024066748W WO 2025008166 A1 WO2025008166 A1 WO 2025008166A1
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WO
WIPO (PCT)
Prior art keywords
stator
core structure
sectors
stator core
ring
Prior art date
Application number
PCT/EP2024/066748
Other languages
French (fr)
Inventor
Jyri PELTOLA
Tuomo Peltola
Juha PYRHÖNEN
Original Assignee
Lekatech Oy
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 Lekatech Oy filed Critical Lekatech Oy
Publication of WO2025008166A1 publication Critical patent/WO2025008166A1/en

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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
    • 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
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D11/00—Portable percussive tools with electromotor or other motor drive
    • B25D11/06—Means for driving the impulse member
    • B25D11/064—Means for driving the impulse member using an electromagnetic drive
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21B—EARTH OR ROCK DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
    • E21B1/00—Percussion drilling
    • E21B1/12—Percussion drilling with a reciprocating impulse member
    • E21B1/22—Percussion drilling with a reciprocating impulse member driven by electromagnets
    • 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
    • H02K33/00—Motors with reciprocating, oscillating or vibrating magnet, armature or coil system
    • 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
    • H02K2201/00—Specific aspects not provided for in the other groups of this subclass relating to the magnetic circuits
    • H02K2201/12—Transversal flux machines
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K33/00—Motors with reciprocating, oscillating or vibrating magnet, armature or coil system
    • H02K33/12—Motors with reciprocating, oscillating or vibrating magnet, armature or coil system with armatures moving in alternate directions by alternate energisation of two coil systems
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K7/00—Arrangements for handling mechanical energy structurally associated with dynamo-electric machines, e.g. structural association with mechanical driving motors or auxiliary dynamo-electric machines
    • H02K7/14—Structural association with mechanical loads, e.g. with hand-held machine tools or fans

Definitions

  • the disclosure relates generally to linear electric machines. More particularly, the disclosure relates to a stator core structure for a tubular linear electric machine. Furthermore, the disclosure relates to a tubular linear electric machine. Furthermore, the disclosure relates to a method for manufacturing a stator core structure of a tubular linear electric machine. Furthermore, the disclosure relates to an electric percussion device that comprises a tubular linear electric machine.
  • a linear electric machine comprises a stator and a mover which is linearly movable with respect to the stator in the longitudinal direction of the linear electric machine.
  • the mover and the stator are provided with magnetically operating means for converting electric energy into linear movement of the mover when the linear electric machine operates as a linear motor, and for converting linear movement of the mover into electric energy when the linear electric machine operates as a linear generator.
  • the magnetically operating means may comprise for example multiphase windings for generating a magnetic field moving with respect to the multiphase windings when alternating currents are supplied to the multiphase windings.
  • the magnetically operating means may comprise equipment for generating force in response to the moving magnetic field generated with the multiphase windings.
  • the above-mentioned equipment may comprise for example permanent magnets, electromagnets, electrically conductive structures, and/or mechanical structures providing a spatial reluctance variation.
  • the multiphase windings can be located in the stator and the equipment for generating force in response to a moving magnetic field can be located in the mover. It is also possible that the multiphase windings are located in the mover and the equipment for generating the force in response to the moving magnetic field is located in the stator.
  • the ferromagnetic structures of electric machines are typically constituted by steel sheets which are stacked to form a laminated structure, and which are electrically insulated from each other.
  • ferromagnetic material such as ferrite or soft magnetic composite “SMC” material, e.g. Somaloy®
  • SMC soft magnetic composite
  • a shape of a ferromagnetic structure can be however such that it is challenging to be manufactured from material of the kind mentioned above.
  • geometric when used as a prefix means a geometric concept that is not necessarily a part of any physical object.
  • the geometric concept can be for example a geometric point, a straight or curved geometric line, a geometric plane, a non-planar geometric surface, a geometric space, or any other geometric entity that is zero, one, two, or three dimensional.
  • a stator core structure for a tubular linear electric machine.
  • a stator core structure according to the invention comprises ring-shaped stator elements stacked in the longitudinal direction of the stator core structure.
  • Each of the ring-shaped stator elements is constituted by two or more sectors comprising ferromagnetic material and attached to each other.
  • the sectors are easier to manufacture from, for example, sintered ferromagnetic material such as ferrite or soft magnetic composite “SMC” material, e.g. Somaloy® than ring-shaped elements.
  • sintered ferromagnetic material such as ferrite or soft magnetic composite “SMC” material, e.g. Somaloy® than ring-shaped elements.
  • joint surfaces between the above-mentioned sectors coincide geometric planes each coinciding with a longitudinal geometric center line of the stator core structure. Therefore, the joints between the above-mentioned sectors are oriented so that a magnetic flux does not need to penetrate the joints and thus the joints do not disturb the electro-magnetic operation of the tubular linear electric machine.
  • a new tubular linear electric machine that comprises:
  • stator comprising a stator core structure according to the invention
  • the stator comprises windings surrounding the mover and configured to generate a magnetic force directed to the mover in response to electric currents supplied to the windings.
  • a new electric percussion device that comprises:
  • a frame attachable to a working machine such as e.g. an excavator
  • the frame comprising attachment members configured to attach to the working machine so that the frame is nondestructively detachable from the working machine, an actuator member, e.g. a chisel, linearly movably supported with respect to the frame, and - a tubular linear electric machine according to the invention.
  • the stator of the tubular linear electric machine is attached to the frame and the mover of the tubular linear electric machine is configured to direct impacts to the actuator member.
  • a new method for manufacturing a stator core structure for a tubular linear electric machine comprises:
  • stator core structure - stacking the ring-shaped stator elements in a longitudinal direction of the stator core structure and attaching the ring-shaped stator elements to each other to compose the stator core structure.
  • figures 1 a, 1 b, 1 c, and 1 d illustrate a linear electric machine according to an exemplifying and non-limiting embodiment
  • figure 2 illustrates an electric percussion device that comprises a linear electric machine according to an exemplifying and non-limiting embodiment
  • figure 3 shows a flowchart of a method according to an exemplifying and non-limiting embodiment for manufacturing a stator core structure for a tubular linear electric machine.
  • Figure 1 a shows a section view of a part of a tubular linear electric machine 100 according to an exemplifying and non-limiting embodiment.
  • the section plane is parallel with the yz-plane of a coordinate system 199.
  • the tubular linear electric machine comprises a stator 101 and a mover 102.
  • the mover 102 is linearly movable with respect to the stator 101 in the longitudinal direction of the tubular linear electric machine.
  • the longitudinal direction is parallel with the z-axis of the coordinate system 199.
  • the stator 101 comprises a stator core-structure 103 according to an exemplifying and non-limiting embodiment and windings surrounding the mover 102 and configured to generate a magnetic force directed to the mover 102 in response to electric currents supplied to the windings.
  • FIG 1a cross-sections of two coils of the windings are denoted with references 109 and 110.
  • the windings of the stator 101 may constitute for example a multi-phase winding, e.g. a two- or three-phase winding.
  • the stator 101 also comprises a stator frame 120 having cooling channels for conducting cooling fluid, e.g. water or air.
  • one of the cooling channels is denoted with a reference 121 .
  • the stator core structure 103 comprises ring-shaped stator elements stacked in the longitudinal direction of the stator core structure, i.e. in a direction parallel with the z-axis of the coordinate system 199.
  • FIG 1 a two of the ring-shaped stator elements are denoted with references 107 and 108.
  • Each of the ring-shaped stator elements is constituted by sectors comprising ferromagnetic material and attached to each other.
  • each ring-shaped stator element is constituted by four sectors.
  • Figures 1 b and 1 c show that the ring-shaped stator element 107 is constituted by sectors 113a, 113b, 113c, and 113d.
  • the sectors can be attached to each other with adhesive material, such as glue or soldering material, between joint surfaces of adjacent ones of the sectors.
  • the glue may comprise for example epoxy resin.
  • the joints comprise electrically insulating material e.g. resin, the joints inhibit eddy currents in the stator core structure.
  • the sectors are easier to manufacture from for example sintered ferromagnetic material such as ferrite or soft magnetic composite “SMC” material, e.g. Somaloy® than ring-shaped elements.
  • the joint surfaces between the sectors coincide geometric planes each of which coincides with a longitudinal geometric center line of the stator core structure 103.
  • the longitudinal geometric center line of the stator core structure 103 is depicted with a dash-and-dot line 122. Therefore, the joints between the sectors are oriented so that a magnetic flux does not need to penetrate the joints, and thus the joints do not disturb the electro-magnetic operation of the tubular linear electric machine.
  • the sectors of the ring-shaped stator elements are shaped to provide passages for electric conductors between the axially successive coils of the windings and for electric conductors for connecting the windings to an external electrical system.
  • Figure 1 d shows the ring-shaped stator element 107 when viewed along an arrow A shown in figure 1 c.
  • a passage for electric conductors is denoted with a reference 114 in figure 1 d. It is however also possible that different arrangements are used for providing passages for electric conductors.
  • a section of each of the ring-shaped stator elements along a geometric section plane coinciding with the longitudinal geometric center line 122 is T-shaped so that annular stator slots for the stator windings are formed between the ring-shaped stator elements which are stacked in the longitudinal direction.
  • the slots are occupied by the coils of the stator windings, such as the coils 109 and 110.
  • the above-mentioned section of each of the ring- shaped stator elements along a geometric section plane of the kind mentioned above is L-shaped so that annular stator slots for stator windings are formed between the ring-shaped stator elements stacked in the longitudinal direction.
  • stator core structure 103 illustrated in figures 1 a-1 d the sectors of the ring-shaped stator elements are identical to each other.
  • the fact that the sectors are identical to each other facilitates manufacturing of the sectors and makes it more cost effective. It is however also possible that in stator core structures according to different embodiments, there are sectors differing from each other concerning e.g. the passages for electric conductors.
  • the mover 102 comprises annular permanent magnets provided one after another in the longitudinal direction of the mover 102, i.e. in the direction of the z-axis of the coordinate system 199.
  • the axial direction of the annular shape of each permanent magnet coincides with the longitudinal direction of the mover 102.
  • two of the annular permanent magnets are denoted with references 1 11 and 112.
  • the magnetizing directions of the permanent magnets coincide with the longitudinal direction of the mover 102 so that north and south poles of each permanent magnet are successively with each other in the longitudinal direction, and the magnetizing directions of successive permanent magnets are opposite to each other.
  • the magnetizing directions of the permanent magnets are indicated with arrows and exemplifying magnetic flux lines are depicted with dashed lines.
  • the mover 102 comprises a center rod 119 and annular ferromagnetic elements provided around the center rod 119 to form a ferromagnetic core structure of the mover 102.
  • two of the annular ferromagnetic elements of the mover 102 are denoted with references 105 and 106.
  • each annular permanent magnet is situated between two successive annular ferromagnetic elements.
  • the center rod 1 19 of the mover 102 is made of non-ferromagnetic material in order to maximize a magnetic coupling between the permanent magnets and the windings of the stator 101 , i.e. to minimize a leakage flux via the center rod 119.
  • the exemplifying tubular linear electric machine illustrated in figure 1 a is a linear permanent magnet machine. It is however also possible that a stator core structure according to an embodiment of the invention is a stator core structure of a linear flux switching permanent magnet synchronous machine ’’FSPMSM” where permanent magnets are located in a stator, or a stator core structure of a reluctance linear electric machine or a linear induction machine in which no permanent magnets are needed.
  • a reluctance linear electric machine the whole magnetic flux is produced by electric currents and a magnetic force directed to the mover is generated by reluctance variation based on the design of the mover.
  • a linear induction machine the whole magnetic flux is produced by electric currents and a magnetic force directed to the mover is generated by currents induced in the mover.
  • FIG. 2 shows a section view of an electric percussion device 230 according to an exemplifying and non-limiting embodiment.
  • the section plane is parallel with the yz- plane of a coordinate system 299.
  • the electric percussion device 230 comprises a frame 231 that comprises attachment members 232 for connecting to a working machine such as e.g. an excavator so that the frame 231 is nondestructively detachable from the working machine.
  • the electric percussion device 230 comprises an actuator member 233, e.g. a chisel, supported with respect to the frame 231 and linearly movable with respect to the frame 231.
  • the electric percussion device 230 comprises a tubular linear electric machine 200 according to an embodiment of the invention.
  • a stator 201 of the tubular linear electric machine is attached to the frame 231 , and a mover 202 of the tubular linear electric machine is configured to direct impacts to the actuator member 233.
  • the tubular linear electric machine 200 can be for example such as the tubular linear electric machine 100 illustrated in figures 1 a-1 d.
  • Figure 3 shows a flowchart of a method according to an exemplifying and nonlimiting embodiment for manufacturing a stator core structure for a tubular linear electric machine.
  • the method comprises the following actions:
  • - action 303 stacking the ring-shaped stator elements in the longitudinal direction of the stator core structure and attaching the ring-shaped stator elements to each other to compose the stator core structure.
  • joint surfaces between adjacent ones of the sectors in each of the ring-shaped stator elements coincide geometric planes each coinciding with a longitudinal geometric center line of the stator core structure.
  • the sectors of the ring-shaped stator elements are identical to each other.
  • the manufacturing of the sectors comprises a sintering process.
  • the sectors are made of ferrite or soft magnetic composite “SMC” material, e.g. Somaloy®.
  • the sectors are attached to each other with adhesive material, e.g. glue or soldering material, between joint surfaces of adjacent ones of the sectors.
  • adhesive material e.g. glue or soldering material
  • a section of each of the ring-shaped stator elements along a geometric section plane coinciding with a longitudinal geometric center line of the stator core structure is T- or L-shaped so that annular stator slots for stator windings are formed between the ring-shaped stator elements stacked in the longitudinal direction.

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Abstract

A stator core structure (103) for a tubular linear electric machine comprises ring-shaped stator elements (107, 108) stacked in the longitudinal direction (z) of the stator core structure. Each of the ring-shaped stator elements is constituted by two oorr mmoorree sectors comprising ferromagnetic material and attached to each other, where joint surfaces between the sectors coincide geometric planes each coinciding with a longitudinal geometric center line of the stator core structure. The joints between the sectors can be oriented so that a magnetic flux does not need to penetrate the joints and thus the joints do not disturb the electro-magnetic operation of the tubular linear electric machine.

Description

A stator core structure for a tubular linear electric machine
Field of the disclosure
The disclosure relates generally to linear electric machines. More particularly, the disclosure relates to a stator core structure for a tubular linear electric machine. Furthermore, the disclosure relates to a tubular linear electric machine. Furthermore, the disclosure relates to a method for manufacturing a stator core structure of a tubular linear electric machine. Furthermore, the disclosure relates to an electric percussion device that comprises a tubular linear electric machine.
Background
A linear electric machine comprises a stator and a mover which is linearly movable with respect to the stator in the longitudinal direction of the linear electric machine. The mover and the stator are provided with magnetically operating means for converting electric energy into linear movement of the mover when the linear electric machine operates as a linear motor, and for converting linear movement of the mover into electric energy when the linear electric machine operates as a linear generator. The magnetically operating means may comprise for example multiphase windings for generating a magnetic field moving with respect to the multiphase windings when alternating currents are supplied to the multiphase windings. Furthermore, the magnetically operating means may comprise equipment for generating force in response to the moving magnetic field generated with the multiphase windings. The above-mentioned equipment may comprise for example permanent magnets, electromagnets, electrically conductive structures, and/or mechanical structures providing a spatial reluctance variation. The multiphase windings can be located in the stator and the equipment for generating force in response to a moving magnetic field can be located in the mover. It is also possible that the multiphase windings are located in the mover and the equipment for generating the force in response to the moving magnetic field is located in the stator.
In conjunction with linear electric machines, as in conjunction with rotating electric machines, there is a need to minimize eddy currents induced by alternating magnetic fluxes in ferromagnetic structures. Thus, the ferromagnetic structures of electric machines are typically constituted by steel sheets which are stacked to form a laminated structure, and which are electrically insulated from each other. In conjunction with some electric machines, it may be however challenging to construct ferromagnetic structures so that alternating magnetic fluxes flow along steel sheets of the kind mentioned above and the alternating magnetic fluxes do not need to penetrate the steel sheets in directions intersecting the steel sheets. For example, in conjunction with a tubular linear electric machine it can be challenging to achieve a situation where alternating magnetic fluxes flow along steel sheets and do not penetrate the steel sheets in directions intersecting the steel sheets. Another approach to minimize eddy currents induced by alternating magnetic fluxes in ferromagnetic structures is to use sintered ferromagnetic material such as ferrite or soft magnetic composite “SMC” material, e.g. Somaloy®, as material of the ferromagnetic structures. In some cases, for example in conjunction with a stator of a tubular linear electric machine, a shape of a ferromagnetic structure can be however such that it is challenging to be manufactured from material of the kind mentioned above.
Summary
The following presents a simplified summary to provide a basic understanding of some aspects of various invention embodiments. The summary is not an extensive overview of the invention. It is neither intended to identify key or critical elements of the invention nor to delineate the scope of the invention. The following summary merely presents some concepts of the invention in a simplified form as a prelude to a more detailed description of exemplifying embodiments.
In this document, the word “geometric” when used as a prefix means a geometric concept that is not necessarily a part of any physical object. The geometric concept can be for example a geometric point, a straight or curved geometric line, a geometric plane, a non-planar geometric surface, a geometric space, or any other geometric entity that is zero, one, two, or three dimensional.
In accordance with the invention, there is provided a new stator core structure for a tubular linear electric machine. A stator core structure according to the invention comprises ring-shaped stator elements stacked in the longitudinal direction of the stator core structure. Each of the ring-shaped stator elements is constituted by two or more sectors comprising ferromagnetic material and attached to each other.
The sectors are easier to manufacture from, for example, sintered ferromagnetic material such as ferrite or soft magnetic composite “SMC” material, e.g. Somaloy® than ring-shaped elements.
In a stator core structure according to an exemplifying and non-limiting embodiment, joint surfaces between the above-mentioned sectors coincide geometric planes each coinciding with a longitudinal geometric center line of the stator core structure. Therefore, the joints between the above-mentioned sectors are oriented so that a magnetic flux does not need to penetrate the joints and thus the joints do not disturb the electro-magnetic operation of the tubular linear electric machine.
In accordance with the invention, there is also provided a new tubular linear electric machine that comprises:
- a stator comprising a stator core structure according to the invention, and
- a mover linearly movable with respect to the stator in a longitudinal direction of the tubular linear electric machine.
The stator comprises windings surrounding the mover and configured to generate a magnetic force directed to the mover in response to electric currents supplied to the windings.
In accordance with the invention, there is also provided a new electric percussion device that comprises:
- a frame attachable to a working machine such as e.g. an excavator, the frame comprising attachment members configured to attach to the working machine so that the frame is nondestructively detachable from the working machine, an actuator member, e.g. a chisel, linearly movably supported with respect to the frame, and - a tubular linear electric machine according to the invention.
The stator of the tubular linear electric machine is attached to the frame and the mover of the tubular linear electric machine is configured to direct impacts to the actuator member.
In accordance with the invention, there is also provided a new method for manufacturing a stator core structure for a tubular linear electric machine. The method comprises:
- manufacturing sectors of ring-shaped stator elements, the sectors comprising ferromagnetic material,
- attaching the sectors of each of the ring-shaped stator elements to each other to compose the ring-shaped stator elements, and
- stacking the ring-shaped stator elements in a longitudinal direction of the stator core structure and attaching the ring-shaped stator elements to each other to compose the stator core structure.
Exemplifying and non-limiting embodiments are described in accompanied dependent claims.
Exemplifying and non-limiting embodiments both as to constructions and to methods of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific exemplifying and non-limiting embodiments when read in conjunction with the accompanying drawings.
The verbs “to comprise” and “to include” are used in this document as open limitations that neither exclude nor require the existence of un-recited features. The features recited in dependent claims are mutually freely combinable unless otherwise explicitly stated. Furthermore, it is to be understood that the use of “a” or “an”, i.e. a singular form, throughout this document does not exclude a plurality.
Brief description of the figures Exemplifying and non-limiting embodiments and their advantages are explained in greater detail below in the sense of examples and with reference to the accompanying drawings, in which: figures 1 a, 1 b, 1 c, and 1 d illustrate a linear electric machine according to an exemplifying and non-limiting embodiment, figure 2 illustrates an electric percussion device that comprises a linear electric machine according to an exemplifying and non-limiting embodiment, and figure 3 shows a flowchart of a method according to an exemplifying and non-limiting embodiment for manufacturing a stator core structure for a tubular linear electric machine.
Description of the exemplifying embodiments
The specific examples provided in the description given below should not be construed as limiting the scope and/or the applicability of the appended claims. Lists and groups of examples provided in the description given below are not exhaustive unless otherwise explicitly stated.
Figure 1 a shows a section view of a part of a tubular linear electric machine 100 according to an exemplifying and non-limiting embodiment. The section plane is parallel with the yz-plane of a coordinate system 199. The tubular linear electric machine comprises a stator 101 and a mover 102. The mover 102 is linearly movable with respect to the stator 101 in the longitudinal direction of the tubular linear electric machine. The longitudinal direction is parallel with the z-axis of the coordinate system 199.
The stator 101 comprises a stator core-structure 103 according to an exemplifying and non-limiting embodiment and windings surrounding the mover 102 and configured to generate a magnetic force directed to the mover 102 in response to electric currents supplied to the windings. In figure 1a, cross-sections of two coils of the windings are denoted with references 109 and 110. The windings of the stator 101 may constitute for example a multi-phase winding, e.g. a two- or three-phase winding. In this exemplifying case, the stator 101 also comprises a stator frame 120 having cooling channels for conducting cooling fluid, e.g. water or air. In figure 1 a, one of the cooling channels is denoted with a reference 121 .
The stator core structure 103 comprises ring-shaped stator elements stacked in the longitudinal direction of the stator core structure, i.e. in a direction parallel with the z-axis of the coordinate system 199. In figure 1 a, two of the ring-shaped stator elements are denoted with references 107 and 108. Each of the ring-shaped stator elements is constituted by sectors comprising ferromagnetic material and attached to each other. In this exemplifying case, each ring-shaped stator element is constituted by four sectors. Figures 1 b and 1 c show that the ring-shaped stator element 107 is constituted by sectors 113a, 113b, 113c, and 113d. The sectors can be attached to each other with adhesive material, such as glue or soldering material, between joint surfaces of adjacent ones of the sectors. The glue may comprise for example epoxy resin. When the joints comprise electrically insulating material e.g. resin, the joints inhibit eddy currents in the stator core structure.
The sectors are easier to manufacture from for example sintered ferromagnetic material such as ferrite or soft magnetic composite “SMC” material, e.g. Somaloy® than ring-shaped elements. In the exemplifying stator core structure 103, the joint surfaces between the sectors coincide geometric planes each of which coincides with a longitudinal geometric center line of the stator core structure 103. In figure 1 a, the longitudinal geometric center line of the stator core structure 103 is depicted with a dash-and-dot line 122. Therefore, the joints between the sectors are oriented so that a magnetic flux does not need to penetrate the joints, and thus the joints do not disturb the electro-magnetic operation of the tubular linear electric machine.
The sectors of the ring-shaped stator elements are shaped to provide passages for electric conductors between the axially successive coils of the windings and for electric conductors for connecting the windings to an external electrical system. Figure 1 d shows the ring-shaped stator element 107 when viewed along an arrow A shown in figure 1 c. A passage for electric conductors is denoted with a reference 114 in figure 1 d. It is however also possible that different arrangements are used for providing passages for electric conductors. As illustrated in figure 1 a, a section of each of the ring-shaped stator elements along a geometric section plane coinciding with the longitudinal geometric center line 122 is T-shaped so that annular stator slots for the stator windings are formed between the ring-shaped stator elements which are stacked in the longitudinal direction. The slots are occupied by the coils of the stator windings, such as the coils 109 and 110. It is however also possible that the above-mentioned section of each of the ring- shaped stator elements along a geometric section plane of the kind mentioned above is L-shaped so that annular stator slots for stator windings are formed between the ring-shaped stator elements stacked in the longitudinal direction.
In the exemplifying stator core structure 103 illustrated in figures 1 a-1 d, the sectors of the ring-shaped stator elements are identical to each other. The fact that the sectors are identical to each other facilitates manufacturing of the sectors and makes it more cost effective. It is however also possible that in stator core structures according to different embodiments, there are sectors differing from each other concerning e.g. the passages for electric conductors.
In the exemplifying tubular linear electric machine illustrated in figure 1a, the mover 102 comprises annular permanent magnets provided one after another in the longitudinal direction of the mover 102, i.e. in the direction of the z-axis of the coordinate system 199. The axial direction of the annular shape of each permanent magnet coincides with the longitudinal direction of the mover 102. In figure 1 a, two of the annular permanent magnets are denoted with references 1 11 and 112. The magnetizing directions of the permanent magnets coincide with the longitudinal direction of the mover 102 so that north and south poles of each permanent magnet are successively with each other in the longitudinal direction, and the magnetizing directions of successive permanent magnets are opposite to each other. In figure 1 a, the magnetizing directions of the permanent magnets are indicated with arrows and exemplifying magnetic flux lines are depicted with dashed lines. In this exemplifying case, the mover 102 comprises a center rod 119 and annular ferromagnetic elements provided around the center rod 119 to form a ferromagnetic core structure of the mover 102. In figure 1a, two of the annular ferromagnetic elements of the mover 102 are denoted with references 105 and 106. As shown in figure 1 a, each annular permanent magnet is situated between two successive annular ferromagnetic elements. Advantageously, the center rod 1 19 of the mover 102 is made of non-ferromagnetic material in order to maximize a magnetic coupling between the permanent magnets and the windings of the stator 101 , i.e. to minimize a leakage flux via the center rod 119.
The exemplifying tubular linear electric machine illustrated in figure 1 a is a linear permanent magnet machine. It is however also possible that a stator core structure according to an embodiment of the invention is a stator core structure of a linear flux switching permanent magnet synchronous machine ’’FSPMSM” where permanent magnets are located in a stator, or a stator core structure of a reluctance linear electric machine or a linear induction machine in which no permanent magnets are needed. In a reluctance linear electric machine, the whole magnetic flux is produced by electric currents and a magnetic force directed to the mover is generated by reluctance variation based on the design of the mover. Correspondingly, in a linear induction machine, the whole magnetic flux is produced by electric currents and a magnetic force directed to the mover is generated by currents induced in the mover.
Figure 2 shows a section view of an electric percussion device 230 according to an exemplifying and non-limiting embodiment. The section plane is parallel with the yz- plane of a coordinate system 299. The electric percussion device 230 comprises a frame 231 that comprises attachment members 232 for connecting to a working machine such as e.g. an excavator so that the frame 231 is nondestructively detachable from the working machine. The electric percussion device 230 comprises an actuator member 233, e.g. a chisel, supported with respect to the frame 231 and linearly movable with respect to the frame 231. The electric percussion device 230 comprises a tubular linear electric machine 200 according to an embodiment of the invention. A stator 201 of the tubular linear electric machine is attached to the frame 231 , and a mover 202 of the tubular linear electric machine is configured to direct impacts to the actuator member 233. The tubular linear electric machine 200 can be for example such as the tubular linear electric machine 100 illustrated in figures 1 a-1 d.
It is, however, worth noting that an electric percussion device of the kind described above is only one exemplifying application for a tubular linear electric machine according to an embodiment of the invention, but linear electric machines according to embodiments of the invention can be used in many other applications too.
Figure 3 shows a flowchart of a method according to an exemplifying and nonlimiting embodiment for manufacturing a stator core structure for a tubular linear electric machine. The method comprises the following actions:
- action 301 : manufacturing sectors of ring-shaped stator elements, the sectors comprising ferromagnetic material,
- action 302: attaching the sectors of each of the ring-shaped stator elements to each other to compose the ring-shaped stator elements, and
- action 303: stacking the ring-shaped stator elements in the longitudinal direction of the stator core structure and attaching the ring-shaped stator elements to each other to compose the stator core structure.
In a method according to an exemplifying and non-limiting embodiment, joint surfaces between adjacent ones of the sectors in each of the ring-shaped stator elements coincide geometric planes each coinciding with a longitudinal geometric center line of the stator core structure.
In a method according to an exemplifying and non-limiting embodiment, the sectors of the ring-shaped stator elements are identical to each other.
In a method according to an exemplifying and non-limiting embodiment, the manufacturing of the sectors comprises a sintering process.
In a method according to an exemplifying and non-limiting embodiment, the sectors are made of ferrite or soft magnetic composite “SMC” material, e.g. Somaloy®.
In a method according to an exemplifying and non-limiting embodiment, the sectors are attached to each other with adhesive material, e.g. glue or soldering material, between joint surfaces of adjacent ones of the sectors.
In a method according to an exemplifying and non-limiting embodiment, a section of each of the ring-shaped stator elements along a geometric section plane coinciding with a longitudinal geometric center line of the stator core structure is T- or L-shaped so that annular stator slots for stator windings are formed between the ring-shaped stator elements stacked in the longitudinal direction.
The specific examples provided in the description given above should not be construed as limiting the applicability and/or the interpretation of the appended claims. Lists and groups of examples provided in the description given above are not exhaustive unless otherwise explicitly stated.

Claims

What is claimed is:
1. A stator core structure (103) for a tubular linear electric machine, the stator core structure comprising ring-shaped stator elements (107, 108) stacked in a longitudinal direction (z) of the stator core structure, characterized in that each of the ring-shaped stator elements is constituted by two or more sectors (113a-113d) comprising ferromagnetic material and attached to each other.
2. A stator core structure according to claim 1 , wherein joint surfaces between adjacent ones of the sectors in each of the ring-shaped stator elements coincide geometric planes each coinciding with a longitudinal geometric center line (122) of the stator core structure.
3. A stator core structure according to claim 1 or 2, wherein the sectors (11 Sa- 113d) of the ring-shaped stator elements are identical to each other.
4. A stator core structure according to any one of claims 1-3, wherein the sectors (113a-113d) are made of ferrite or soft magnetic composite material.
5. A stator core structure according to claim 4, wherein the soft magnetic composite material is Somaloy®.
6. A stator core structure according to any one of claims 1-5, wherein the sectors (113a-113d) are attached to each other with adhesive material between the joint surfaces of adjacent ones of the sectors.
7. A stator core structure according to claim 6, wherein the adhesive material is electrically non-conductive.
8. A stator core structure according to any one of claims 1 -7, wherein a section of each of the ring-shaped stator elements (107, 108) along a geometric section plane coinciding with the longitudinal geometric center line (122) of the stator core structure is T- or L-shaped so that annular stator slots for stator windings are formed between the ring-shaped stator elements stacked in the longitudinal direction.
9. A tubular linear electric machine (100, 200) comprising: a stator (101 , 201 ) comprising a stator core structure (103) according to any one of claims 1 -8, and
- a mover (102, 202) linearly movable with respect to the stator in a longitudinal direction of the tubular linear electric machine, wherein the stator comprises windings (109, 110) surrounding the mover and configured to generate a magnetic force directed to the mover in response to electric currents supplied to the windings.
10. An electric percussion device (230) comprising:
- a frame (231 ) attachable to a working machine, the frame comprising attachment members (232) configured to attach to the working machine so that the frame is nondestructively detachable from the working machine,
- an actuator member (233) linearly movably supported with respect to the frame, and
- a tubular linear electric machine (200) according to claim 9, wherein the stator (201 ) of the tubular linear electric machine is attached to the frame and the mover (202) of the tubular linear electric machine is configured to direct impacts to the actuator member (233).
11. A method for manufacturing a stator core structure for a tubular linear electric machine, characterized in that the method comprises:
- manufacturing (301 ) sectors of ring-shaped stator elements, the sectors comprising ferromagnetic material,
- attaching (302) the sectors of each of the ring-shaped stator elements to each other to compose the ring-shaped stator elements, and
- stacking (303) the ring-shaped stator elements in a longitudinal direction of the stator core structure and attaching the ring-shaped stator elements to each other to compose the stator core structure.
12. A method according to claim 11 , wherein joint surfaces between adjacent ones of the sectors in each of the ring-shaped stator elements coincide geometric planes each coinciding with a longitudinal geometric center line (122) of the stator core structure.
13. A method according to claim 11 or 12, wherein the sectors of the ring-shaped stator elements are identical to each other.
14. A method according to any one of claims 11 -13, wherein the sectors are made of ferrite or soft magnetic composite material.
15. A method according to any one of claims 11 -14, wherein the sectors are attached to each other with adhesive material between joint surfaces of adjacent ones of the sectors.
16. A method according to any one of claims 11 -15, wherein a section of each of the ring-shaped stator elements along a geometric section plane coinciding with a longitudinal geometric center line of the stator core structure is T- or L-shaped so that annular stator slots for stator windings are formed between the ring-shaped stator elements stacked in the longitudinal direction.
PCT/EP2024/066748 2023-07-05 2024-06-17 A stator core structure for a tubular linear electric machine WO2025008166A1 (en)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130154397A1 (en) * 2011-12-19 2013-06-20 John T. Sullivan High efficiency magnetic core electrical machines
EP2662962A2 (en) * 2012-05-11 2013-11-13 Waltec Maschinen GmbH Linear motor designed according to the longitudinal flow principle
EP3692217B1 (en) * 2017-10-06 2022-08-10 Lekatech Oy A hammer device

Family Cites Families (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE468292C (en) * 1926-03-14 1928-11-09 Siemens Schuckertwerke Akt Ges AC induction hammer
JP3862885B2 (en) * 1999-03-09 2006-12-27 山洋電気株式会社 Cylinder type linear synchronous motor
US20070108850A1 (en) * 2005-11-17 2007-05-17 Tiax Llc Linear electrical machine for electric power generation or motive drive
FI130138B (en) * 2018-09-21 2023-03-10 Lekatech Oy A linear electric machine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20130154397A1 (en) * 2011-12-19 2013-06-20 John T. Sullivan High efficiency magnetic core electrical machines
EP2662962A2 (en) * 2012-05-11 2013-11-13 Waltec Maschinen GmbH Linear motor designed according to the longitudinal flow principle
EP3692217B1 (en) * 2017-10-06 2022-08-10 Lekatech Oy A hammer device

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