SE544396C2 - Bolt, Electric Machine Component, Electric Machine, and Vehicle - Google Patents

Abstract

A bolt (1) is disclosed configured to attach an electric plate laminate (3, 3’) to a structural component (4, 4’) of an electric machine (6). The bolt (1) comprises a plate laminate section (9), a component section (7), a first abutment surface (21) arranged between the component section (7) and the plate laminate section (9), and a first fastening section (13) configured to receive a first fastening element (15). The component section (7) is arranged between the first fastening section (13) and the first abutment surface (21). The first abutment surface (21) has a surface normal component (c1) facing in a direction towards the component section (7). The present disclosure further relates to an electric machine component (20, 30), and electric machine (6), and a vehicle (40) comprising an electric machine (6).

Description

Bolt, Electric Machine Component, Electric Machine, and Vehicle TECHNICAL FIELD The present disclosure relates to a bolt configured to attach an electric plate laminate to astructural component of an electric machine. The present disclosure further relates to anelectric machine component, an electric machine, and a vehicle comprising an electric machine.

BACKGROUND The use of electric drive for vehicles provides many advantages, especially regarding localemissions. Such vehicles comprise one or more electric machines configured to providemotive power to the vehicle. These types of vehicles can be divided into the category's pureelectric vehicles and hybrid electric vehicles. Pure electric vehicles, sometimes referred to asbattery electric vehicles, only-electric vehicles, and all-electric vehicles, comprise a pureelectric powertrain and comprise no internal combustion engine and therefore produce no emissions in the place where they are used.

A hybrid electric vehicle comprises two or more distinct types of power, such as an internalcombustion engine and an electric propulsion system. The combination of an internalcombustion engine and an electric propulsion system provides advantages with regard toenergy efficiency, partly because of the poor energy efficiency of an internal combustionengine at lower power output levels. Moreover, some hybrid electric vehicles are capable of operating in pure electric drive when wanted, such as when driving in certain areas.

An electric machine is a machine that converts electrical energy into mechanical energy andvice versa. Most electric machines comprise magnets and a wire winding, wherein theelectric machine operate through the interaction between the magnetic field of the magnetsand electric current in the wire winding to generate force in the form of rotation of a rotor ofthe electric machine. The rotor is usually surrounded by a stator. Some electric machinescomprise magnets in the rotor and wire winding in the stator and some other electric machines comprise wire winding in the rotor and magnets in the stator.

An electric machine stator, as well as an electric machine rotor, may comprise many thinmetal sheets, approximately 0.5 mm thick, which are stacked to a desired height. The sheetsare then usually glued or weld together. A collection of sheets is usually referred to as anelectric plate laminate. Today many stators are shrink-fitted directly in an aluminium housing or shrink-fitted in a steel sleeve which are then bolted in a housing. The method of shrink- 2 fitting may put load and stress on the components of the electric machine, such as thehousing and the electric plate laminate. There are also solutions where the stator is boltedthrough the stator sheets, but it can be complicated to retain the bolt tension due to the many stator sheets.

The conventional way of bolting a stator to a housing is to bolt through the stator stack intothe housing. A problem with such a solution is that the stator comprises hundreds of statorsheets. Moreover, an electric machine is usually subjected to a lot of vibration and heatcycling. Over time there is a big risk of embedment in the stator stack. This will result in lossof bolt tension. Moreover, welded components can be associated with durability issues over time and the process of welding is time-consuming during assembly of an electric machine. ln addition, generally, on today's consumer market, it is an advantage if products, such aselectric machines and their associated components, have conditions and/or characteristicssuitable for being manufactured and assembled in a cost-efficient manner. The assemblingcost of an electric machine constitutes a great proportion of the final cost of the electric machine.

SUMMARYlt is an object of the present invention to overcome, or at least alleviate, at least some of the above-mentioned problems and drawbacks.

According to a first aspect of the invention, the object is achieved by a bolt configured toattach an electric plate laminate to a structural component of an electric machine. The boltcomprises a plate laminate section configured to extend through an opening of electric platelaminate, a component section configured to extend through an opening of the structuralcomponent, a first abutment surface arranged between the component section and the platelaminate section, and a first fastening section configured to receive a first fastening element.The component section is arranged between the first fastening section and the first abutmentsurface. The first abutment surface has a surface normal component facing in a direction towards the component section.

Since the bolt comprises the first fastening section and the first abutment surface having thesurface normal component facing in a direction towards the component section, anassembler, or an assembling machine, may in a quick and simple manner attach the platelaminate section, and thus also an electric plate laminate attached thereto, to the structural component simply by inserting the component section through an opening of the structural 3 component and attach a first fastening element to the first fastening section. Thus, a bolt isprovided allowing an assembler, or an assembling machine, to attach an electric platelaminate to a structural component of an electric machine in a quick, simple, and reliable mannel".

Moreover, due to these features, a bolt is provided in which the tension bet\Neen the firstfastening element and the first abutment surface is independent of any fastening tensionused for the electric plate laminate. Thereby, the risk of embedment in the electric platelaminate resulting in loss of bolt tension can be circumvented. Moreover, the bolt can beretained to the structural component in a more secure manner without putting stress and load onto the electric plate laminate. ln addition, since the bolt comprises the plate laminate section, an assembler, or anassembling machine, may in a quicker and simpler manner align and orient the metal sheetsof the electric plate laminate. Thus, also for this reason, a bolt is provided facilitating assembling of an electric machine.

Accordingly, a further result of these features, a bolt is provided having conditions for reducing manufacturing and assembling costs of electric machines.

Moreover, a bolt is provided circumventing the need for Welding and shrink-fitting. As afurther result, a bolt is provided having conditions for improving durability of electric machines.

Thus, a bolt is provided overcoming, or at least alleviating, at least some of the above- mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the bolt comprises a protruding section comprising the first abutment surface.Thereby, the bolt and an electric plate laminate attached to the plate laminate section of thebolt can be attached to the structural component in a rigid and secure manner while onlyhaving to fasten one fastening element to the bolt, i.e. the first fastening element referred to herein.

Optionally, the first fastening section is threaded. Thereby, the bolt and an electric platelaminate attached to the plate laminate section of the bolt can be attached to the structuralcomponent in a rigid and secure manner, for example by fastening a first fastening element in the form of a nut to the first fastening section.

Optionally, the first abutment surface is configured to abut against a portion of the structuralcomponent. Thereby, the bolt and an electric plate laminate attached to the plate laminatesection of the bolt can be attached to the structural component in a rigid and secure mannerwhile only having to fasten one fastening element to the bolt, i.e. the first fastening elementreferred to herein. Moreover, the need for arranging any further components between thefirst abutment surface and the portion of the structural component is circumvented which facilitates assembly of the electric machine and reduces assembling costs thereof.

Optionally, the bolt comprises a second abutment surface arranged between the componentsection and the plate laminate section, and wherein the second abutment surface has asurface normal component facing in a direction towards the plate laminate section. Thereby,an assembler, or an assembling machine, may in a quick and simple manner attach theelectric plate laminate to the bolt simply by inserting the plate laminate section of the boltthrough an opening of the electric plate laminate and attach a second fastening element tothe second fastening section. Thus, a bolt is provided allowing an assembler, or anassembling machine, to attach an electric plate laminate to a structural component of an electric machine in a quick, simple, and reliable manner.

Optionally, the bolt comprises a second fastening section configured to receive a secondfastening element, and wherein the plate laminate section is arranged between the secondfastening section and the second abutment surface. Thereby, the electric plate laminate canbe attached to the bolt, and thus also to the structural component, in a simple, quick, andreliable manner simply by inserting the bolt through an opening of the electric plate laminateand attaching a second fastening element onto the second fastening section. Moreover, dueto these features, the plate laminate can be attached to the bolt with a tension beingindependent of the tension between the first fastening element and the first abutmentsurface. Thereby, conditions are provided for tensioning the electric plate laminate with atension reducing the risk of embedment in the electric plate laminate and damage to theelectric plate laminate. Moreover, in this manner, a more durable electric machine can be provided.

Optionally, the second fastening section is threaded. Thereby, the electric plate laminate canbe attached to the bolt in a rigid and secure manner, for example by fastening a first fastening element in the form of a nut to the first fastening section.

Optionally, the second abutment surface is configured to abut against a portion of the electricplate laminate. Thereby, an electric plate laminate can be attached to the bolt in a rigid andsecure manner while only having to fasten one fastening element to the bolt, i.e. the secondfastening element referred to herein. Moreover, the need for arranging any furthercomponents between the second abutment surface and the portion of the electric platelaminate is circumvented which facilitates assembly of the electric machine and reduces assembling costs thereof.

Optionally, the component section has a diameter different from the diameter of the platelaminate section. Thereby, a flexible bolt is provided having conditions for being adapted tovarious electric machines and the requirements thereof. Moreover, according to someembodiments of the present disclosure, the interface between the component section andthe plate laminate section, in which the diameter of the bolt is changed, can be utilized as anabutment surface of the bolt for taking up forces originating from a fastening section of thebolt. Thereby, a bolt is provided having conditions for further reducing manufacturing andassembling costs of electric machines, While having conditions for improving durability of electric machines.

Optionally, the component section has a diameter being larger than the diameter of the platelaminate section. Thereby, a bolt is provided having conditions for attaching an electric platelaminate to a structural component of an electric machine in a rigid and secure manner while having a reduced impact on the effective volume of the electric plate laminate.

According to a second aspect of the invention, the object is achieved by an electric machinecomponent comprising an electric plate laminate and a structural component eachcomprising an opening, wherein the electric machine component comprises a bolt accordingto some embodiments of the present disclosure, and wherein the bolt attaches the electric plate laminate to the structural component.

Since the electric machine component comprises a bolt according to some embodiments ofthe present disclosure, and the bolt attaches the electric plate laminate to the structuralcomponent, an electric machine component is provided having conditions for reduced assembling and manufacturing costs.

Moreover, an electric machine component is provided having conditions for a reduced risk ofembedment in the electric plate laminate and thus also a loss of bolt tension, while the need for Welding and shrink-fitting is circumvented When assembling the electric machine 6 component. Thereby, an electric machine component is provided having conditions for improved durability while the manufacturing and assembling costs thereof can be reduced. ln addition, since the bolt of the electric machine component comprises the plate laminatesection, an assembler, or an assembling machine, may in a quicker and simpler manneralign and orient the metal sheets of the electric plate laminate. Thus, also for this reason, an electric machine component is provided having conditions for a facilitated assembly.

Thus, an electric machine component is provided overcoming, or at least alleviating, at leastsome of the above-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the structural component comprises a recess enclosing the first abutment surfaceof the bolt. Thereby, an electric machine component is provided having conditions for afurther rigid and secure connection between the bolt and the structural component, and thusalso between the electric plate laminate and the structural component, without significantly adding costs and complexity to the electric machine component.

Optionally, the electric machine component is a stator for an electric machine, and Whereinthe electric plate laminate is an electric stator plate laminate. Thereby, a stator for an electricmachine is provided having conditions for reduced assembling and manufacturing costs.Moreover, a stator for an electric machine is provided having conditions for improved durability.

Optionally, the structural component is a stator housing. Thereby, a stator for an electricmachine is provided having conditions for a simple, rigid, and durable attachment of the electric plate laminate to the stator housing.

Optionally, the electric machine component is a rotor for an electric machine, and Whereinthe electric plate laminate is an electric rotor plate laminate. Thereby, a rotor for an electricmachine is provided having conditions for reduced assembling and manufacturing costs.Moreover, a rotor for an electric machine is provided having conditions for improved durability.

According to a third aspect of the invention, the object is achieved by an electric machinecomprising an electric machine component according to some embodiments of the present disclosure.

Since the electric machine comprises a bolt according to some embodiments of the presentdisclosure, and the bolt attaches the electric plate laminate to the structural component, anelectric machine is provided having conditions for reduced assembling and manufacturing costs.

Moreover, an electric machine is provided having conditions for a reduced risk of embedmentin the electric plate laminate and thus also a loss of bolt tension, while the need for weldingand shrink-fitting is circumvented When assembling the electric machine. Thereby, an electricmachine is provided having conditions for improved durability While the manufacturing and assembling costs thereof is reduced. ln addition, since the bolt of the electric machine comprises the plate laminate section, anassembler, or an assembling machine, may in a quicker and simpler manner align and orientthe metal sheets of the electric plate laminate. Thus, also for this reason, an electric machine is provided having conditions for a facilitated assembly.

Thus, an electric machine is provided overcoming, or at least alleviating, at least some of theabove-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved.

Optionally, the electric machine is a vehicle propulsion motor. Thereby, a vehicle propulsionmotor is provided having conditions for reduced assembling and manufacturing costs.

Moreover, a vehicle propulsion motor is provided having conditions for improved durability.

According to a fourth aspect of the invention, the object is achieved by a vehicle comprising an electric machine according to some embodiments of the present disclosure.

Since the vehicle comprises an electric machine according to some embodiments, a vehicleis provided having conditions for reduced assembling and manufacturing costs. Moreover, a vehicle is provided having conditions for improved durability.

Accordingly, a vehicle is provided overcoming, or at least alleviating, at least some of theabove-mentioned problems and drawbacks. As a result, the above-mentioned object is achieved. 8 Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS Various aspects of the invention, including its particular features and advantages, will bereadily understood from the example embodiments discussed in the following detailed description and the accompanying drawings, in which: Fig. 1 illustrates an electric machine according to some embodiments, Fig. 2 illustrates a perspective view of a bolt according to some embodiments, Fig. 3 illustrates a cross section of the bolt illustrated in Fig. 2, Fig. 4 illustrates a cross section of a portion of the electric machine illustrated in Fig. 1,Fig. 5 illustrates a cross section of a portion of a rotor for an electric machine according tosome embodiments of the present disclosure, and Fig. 6 illustrates a vehicle according to some embodiments.

DETAILED DESCRIPTION Aspects of the present invention will now be described more fully. Like numbers refer to likeelements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

Fig. 1 illustrates an electric machine 6 according to some embodiments. According to theillustrated embodiments, the electric machine 6 is a vehicle propulsion motor capable ofconverting electrical energy into mechanical energy and capable of converting mechanicalenergy into electrical energy. The vehicle propulsion motor may therefore also be referred toas a vehicle electric propulsion machine 6. The electric machine 6 comprises a stator 20 anda rotor 30. The stator 20 is arranged to induce a magnetic field causing a torque to beapplied to the rotor 30 when the electric machine 6 is converting electrical energy intomechanical energy. Conversely, when the electric machine 6 is converting mechanicalenergy into electrical energy, the rotation of the rotor 30 causes the mechanical energy of the rotor 30 to be converted into electrical energy in the stator 20.

The electric machine 6 comprises a number of bolts 1. As is further explained herein, thebolts 1 are configured to attach an electric plate laminate to a structural component of the electric machine 6. 9 Fig. 2 illustrates a perspective view of a bolt 1 of the number of bolts 1 illustrated in Fig. 1.The bolt 1 comprises a plate laminate section 9. As is further explained herein, the platelaminate section 9 is configured to extend through an opening of an electric plate laminate.Moreover, the bolt 1 comprises a component section 7. The component section 7 isconfigured to extend through an opening of a structural component of an electric machine.The bolt 1 further comprises a first abutment surface 21 arranged between the componentsection 7 and the plate laminate section 9. Moreover, the bolt 1 comprises a first fasteningsection 13 at a first distal end 11 of the bolt 1. The first fastening section 13 is configured toreceive a first fastening element. According to the illustrated embodiments, the first fasteningsection 13 comprises outer threads and is configured to receive a fastening elementcomprising inner threads, such as a nut. As can be seen in Fig. 2, the component section 7 is arranged between the first fastening section 13 and the first abutment surface 21.

Fig. 3 illustrates a cross section of the bolt 1 illustrated in Fig. 2. ln Fig. 2, the cross section ismade through a centre axis of the bolt 1. According to the illustrated embodiments, the bolt 1is rotationally symmetrical, wherein a symmetry axis of the bolt 1 coincides with the centre axis of the bolt 1. Below, simultaneous reference is made to Fig. 1 - Fig. 3.

As can be seen in Fig. 2 and Fig. 3, the bolt 1 comprises a protruding section 10 comprisingthe first abutment surface 21. That is, the first abutment surface 21 is a surface of theprotruding section 10. The protruding section 10 protrudes in radial directions of the bolt 1,i.e. in directions perpendicular to a centre axis thereof. ln other words, the protruding section10 has a greater diameter d3 than the diameter d1 of the component section 7 and thediameter d2 of the plate laminate section 9. The first abutment surface 21 has a surfacenormal component c1 facing in a direction towards the component section 7 and in adirection towards the first fastening section 13. ln this manner, the bolt 1, and an electricplate laminate attached to the plate laminate section 9, can be attached to a structuralcomponent of an electric machine in a quick, simple, and reliable manner, as is further explained herein.

As indicated in Fig. 3, according to the illustrated embodiments, the bolt 1 comprises asecond abutment surface 22. The second abutment surface 22 is arranged between thecomponent section 7 and the plate laminate section 9. ln more detail, according to theillustrated embodiments, the protruding section 10 comprises the second abutment surface22. That is, the second abutment surface 22 is a surface of the protruding section 10. Thesecond abutment surface 22 is arranged on an opposite side of the protruding section 10 than the first abutment surface 21.

According to the illustrated embodiments, the bolt 1 comprises a second fastening section 14at a second distal end 12 of the bolt. The second fastening section 14 is configured toreceive a second fastening element. According to the illustrated embodiments, the secondfastening section 14 comprises outer threads and is configured to receive a fasteningelement comprising inner treads, such as a nut. As can be seen in Fig. 2, the plate laminatesection 9 is arranged between the second fastening section 14 and the second abutmentsurface 22. The second abutment surface 22 has a surface normal component c2 facing in adirection towards the plate laminate section 9 and in a direction towards the second fasteningsection 14. ln this manner, an electric plate laminate can be attached to the bolt 1 in a quick,simple, and reliable manner, as is further explained herein. According to the illustratedembodiments, the surface normal component c2 of the second abutment surface 22 isopposite to the surface normal component c1 of the first abutment surface 21. Furthermore,according to the illustrated embodiments, the surface normal component c1 of the firstabutment surface 21 and the surface normal component c2 of the second abutment surface22 is each parallel to a centre axis of the bolt 1. According to further embodiments, one orboth of the first and second abutment surfaces 21, 22 may be conical or frusto-conical. lnsuch a case, a surface normal of the conical or frusto-conical abutment surface 21, 22 isangled relative to the centre axis of the bolt 1. However, also such a surface normal comprise a surface normal component c1, c2 parallel to a centre axis of the bolt 1.

Fig. 4 illustrates a cross section of a portion of the electric machine 6 illustrated in Fig. 1. lnFig. 4, the cross section is made in a plane comprising a rotation axis of the rotor 30 of the electric machine 6.

The electric machine 6 comprises a bolt 1 according to the embodiments explained withreference to Fig. 2 and Fig. 3. The bolt 1 attaches an electric plate laminate 3 to a structuralcomponent 4 the electric machine 6. According to the illustrated embodiments, the structuralcomponent 4 is a stator housing 4. According to further embodiments, the structuralcomponent 4, as referred to herein, may be another type of structural component configuredto hold the electric plate laminate 3 relative to the rotor 30 of the electric machine 6.Moreover, according to the embodiments illustrated in Fig. 4, the electric plate laminate 3 is an electric stator plate laminate 3.

As can be seen in Fig. 4, the plate laminate section 9 of the bolt 1 extends through anopening 8' of electric plate laminate 3. According to the illustrated embodiments, the opening 8' is a through hole of the electric plate laminate 3. According to further embodiments, the 11 opening 8' may be another type of opening, such as a slot, or the like. Moreover, as can beseen in Fig. 4, the component section 7 extends through an opening 8 of the structuralcomponent 4. According to the illustrated embodiments, the opening 8 of the structuralcomponent 4 is a through hole of the structural component 4. According to furtherembodiments, the opening 8 of the structural component 4 may be another type of opening, such as a slot.

As can be seen in Fig. 4, the first abutment surface 21 abuts against a portion 23 of thestructural component 4. Likewise, according to the illustrated embodiments, the secondabutment surface 22 is abutting against a portion 25 of the electric plate laminate 3. Due tothese features, the assembly of the stator 20 is significantly facilitated. That is, an assembler,or an assembling machine, may thread the plate laminate section 9 of the bolt 1 throughopenings 8' of plates constituting the electric plate laminate 3. ln this manner, the bolt 1 canfacilitate alignment and orientation of the plates constituting the electric plate laminate 3.Then, the assembler, or an assembling machine, may fasten a second fastening element 15'to the second fastening section 14 to secure the electric plate laminate 3 to the bolt 1. Then,the assembler, or an assembling machine, may tread the component section 7 of the bolt 1through the opening 8 of the structural component 4 and attach a first fastening element 15to the first fastening section 13 to secure the electric plate laminate 3 to the structuralcomponent 4. ln this manner, an assembler, or an assembling machine, can attach theelectric plate laminate 3 to the structural component 4 in a quick, simple, and reliablemanner. According to the illustrated embodiments, a washer 16 is also arranged on the firstand second fastening sections 13, 14 inside of the respective first and second fastening element 15, 15'. Moreover, in Fig. 1, a set of second fastening elements 15' are indicated.

Moreover, due to the features of the bolt 1, the first fastening element 15 can be tightenedwithout affecting the tension applied to the electric plate laminate 3 and the second fasteningelement 15'. Furthermore, due to these features, the second fastening element 15' can betightened to provide a low strain on the electric plate laminate 3 and avoiding embedment in the electric plate laminate 3.

According to the embodiments illustrated in Fig. 4, and as is indicated in Fig. 3, thecomponent section 7 has a diameter d1 being larger than the diameter d2 of the platelaminate section 9. ln this manner, the bolt 1 can attach an electric plate laminate 3 to thestructural component 4 of the electric machine 6 in a rigid and secure manner While having a reduced impact on the effective volume of the electric plate laminate 3. 12 According to further embodiments of the herein described, plate laminate section 9 may havea diameter d1 being larger than the diameter d2 of the component section 7. Moreover, theprotruding section 10 of the bolt 1 may be formed by a component attached to the bolt 1,such as an open washer arranged in a groove of the bolt 1. Furthermore, according to someembodiments of the herein described, one or both of the first and second abutment surfaces21, 22 may be formed by a surface constituting a change in the diameter of the bolt 1. Thatis, one or both of the first and second abutment surfaces 21, 22 may be formed at aninterface between the component section 7 and the plate laminate section 9, in which thediameter of the bolt is changed. Thus, the interface between the component section 7 andthe plate laminate section 9 can be utilized as an abutment surface of the bolt 1 for taking up forces originating from a fastening section 13, 14 of the bolt 1.

As can be seen in Fig. 4, according to the illustrated embodiments, the structural component4 comprises a recess 19 enclosing the first abutment surface 21 of the bolt 1. ln more detail,the recess 19 encloses at least part of the protruding section 10 of the bolt 1. According tothe illustrated embodiments, the recess 19 is circular and has an inner diameter slightlylarger than the outer diameter of the protruding section 10 of the bolt 1. According to furtherembodiments of the herein described, the protruding section 10 and the recess 19 may eachhave another shape than circular, such as a polygonal shape. Due to the recess 19, a furtherrigid and secure connection is provided between the bolt 1 and the structural component 4,and thus also between the electric plate laminate 3 and the structural component 4, without significantly adding costs and complexity to the electric machine 6.

Fig. 5 illustrates a cross section of a portion of a rotor 30 for an electric machine according tosome embodiments of the present disclosure. ln Fig. 5, the cross section is made in a plane comprising a rotation axis of the rotor 30.

The rotor 30 comprises a bolt 1 according to the embodiments explained with reference toFig. 2 and Fig. 3. The bolt 1 attaches an electric plate laminate 3' to a structural component4' the rotor 30. According to the illustrated embodiments, the structural component 4' is acomponent attached to a rotor hub 26 of the rotor 30. According to further embodiments, thestructural component 4', as referred to herein, may be another type of structural componentconfigured to hold the electric plate laminate 3' upon rotation of the rotor 30, such as a rotorhub 26, or the like. Moreover, according to the embodiments illustrated in Fig. 5, the electric plate laminate 3' is an electric rotor plate laminate 3”. 13 As can be seen in Fig. 5, the plate laminate section 9 of the bolt 1 extends through anopening 8' of electric plate laminate 3'. According to the illustrated embodiments, the opening8' is a through hole of the electric plate laminate 3'. According to further embodiments, theopening 8' may be another type of opening, such as a slot, or the like. Moreover, as can beseen in Fig. 5, the component section 7 extends through an opening 8 of the structuralcomponent 4'. According to the illustrated embodiments, the opening 8 is a through hole ofthe structural component 4'. According to further embodiments, the opening 8 of the structural component 4' may be another type of opening, such as a slot.

As can be seen in Fig. 5, the first abutment surface 21 abuts against a portion 23 of thestructural component 4'. Likewise, according to the illustrated embodiments, the secondabutment surface 22 is abutting against a portion 25 of the electric plate laminate 3'. Due tothese features, the assembly of the rotor 30 is significantly facilitated. That is, an assembler,or an assembling machine, may thread the plate laminate section 9 of the bolt 1 throughopenings 8' of plates constituting the electric plate laminate 3'. ln this manner, the bolt 1 canfacilitate alignment and orientation of the plates constituting the electric plate laminate 3'.Then, the assembler, or an assembling machine, may fasten a second fastening element 15'to the second fastening section 14 to secure the electric plate laminate 3' to the bolt 1. Then,the assembler, or an assembling machine, may tread the component section 7 of the bolt 1through the opening 8 of the structural component 4' and attach a first fastening element 15to the first fastening section 13 to secure the electric plate laminate 3' to the structuralcomponent 4'. ln this manner, an assembler, or an assembling machine, can attach theelectric plate laminate 3' to the structural component 4' of the rotor 30 in a quick, simple, andreliable manner. According to the illustrated embodiments, a washer 16 is also arranged onthe first and second fastening sections 13, 14 inside of the respective first and second fastening element 15, 15'.

Moreover, due to the features of the bolt 1, the first fastening element 15 can be tightenedwithout affecting the tension applied to the electric plate laminate 3' and the second fasteningelement 15'. Furthermore, the second fastening element 15' can be tightened to provide alow strain on the electric plate laminate 3' and avoiding embedment in the electric plate laminate 3'.

According to the embodiments illustrated in Fig. 5, and as is indicated in Fig. 3, thecomponent section 7 has a diameter d1 being larger than the diameter d2 of the plate laminate section 9. ln this manner, the bolt 1 can attach an electric plate laminate 3' to the 14 structural component 4' of the rotor 30 in a rigid and secure manner while having a reduced impact on the effective volume of the electric plate laminate 3”.

According to further embodiments of the herein described, plate laminate section 9 may havea diameter d1 being larger than the diameter d2 of the component section 7. Moreover, theprotruding section 10 of the bolt may be formed by a component attached to the bolt 1, suchas an open washer arranged in a groove of the bolt 1. Furthermore, according to someembodiments of the herein described, one or both of the first and second abutment surfaces21, 22 may be formed by a surface constituting a change in the diameter of the bolt 1. Thatis, one or both of the first and second abutment surfaces 21, 22 may be formed at aninterface between the component section 7 and the plate laminate section 9, in which thediameter of the bolt is changed. Thus, the interface between the component section 7 andthe plate laminate section 9 can be utilized as an abutment surface of the bolt 1 for taking up forces originating from a fastening section 13, 14 of the bolt 1.

As can be seen in Fig. 5, according to the illustrated embodiments, the structural component4' comprises a recess 19 enclosing the first abutment surface 21 of the bolt 1. ln more detail,the recess 19 encloses at least part of the protruding section 10 of the bolt 1. According tothe illustrated embodiments, the recess 19 is circular and has an inner diameter slightlylarger than the outer diameter of the protruding section 10 of the bolt 1. According to furtherembodiments of the herein described, the protruding section 10 and the recess 19 may eachhave another shape than circular, such as a polygonal shape. Due to the recess 19, a furtherrigid and secure connection is provided between the bolt 1 and the structural component 4',and thus also between the electric plate laminate 3' and the structural component 4', without significantly adding costs and complexity to the electric machine 6.

Fig. 6 illustrates a vehicle 40 according to some embodiments. The vehicle 40 comprises anelectric machine 6 according to the embodiments illustrated in Fig. 1. As an alternative, or inaddition, the electric machine 6 may comprise a rotor 30 explained with reference to Fig. 5.The electric machine 6 is configured to provide motive power to the vehicle 40 via wheels 52of the vehicle 40. According to the illustrated embodiments, the vehicle 40 is a truck, i.e. aheavy vehicle. However, according to further embodiments, the vehicle 40, as referred toherein, may be another type of manned or unmanned vehicle for land or water basedpropulsion such as a lorry, a bus, a construction vehicle, a tractor, a car, a ship, a boat, orthe like. Moreover, according to the illustrated embodiments, the vehicle 40 is a fully electricvehicle. However, according to further embodiments, the vehicle 40, as referred to herein, may be a hybrid electric vehicle also comprising a combustion engine.

The wording “structural component” as used herein encompasses a component whosepurpose is to rigidly hold the electric plate laminate referred to herein. Moreover, asunderstood from the herein described, an electric machine component 20, 30 may comprisea number of bolts 1 circumferentially distributed to attach a electric plate laminate 3, 3' to a structural component 4, 4' of the electric machine component 20, 30. lt is to be understood that the foregoing is illustrative of various example embodiments andthat the invention is defined only by the appended claims. A person skilled in the art willrealize that the example embodiments may be modified, and that different features of theexample embodiments may be combined to create embodiments other than those describedherein, Without departing from the scope of the present invention, as defined by the appended claims.

As used herein, the term "comprising" or "comprises" is open-ended, and includes one ormore stated features, elements, steps, components, or functions but does not preclude thepresence or addition of one or more other features, elements, steps, components, functions, or groups thereof.

Claims (18)

1. A bolt (1) configured to attach an electric plate laminate (3, 3') to a structural component(4, 4') of an electric machine (6), wherein the bolt (1) comprises:- a plate laminate section (9) configured to extend through an opening (8') of electricplate laminate (3, 3'),- a component section (7) configured to extend through an opening (8) of the structuralcomponent (4, 4'),- a first abutment surface (21) arranged between the component section (7) and theplate laminate section (9), and- a first fastening section (13) configured to receive a first fastening element (15),wherein the component section (7) is arranged between the first fastening section(13) and the first abutment surface (21 ),and wherein the first abutment surface (21) has a surface normal component (c1) facing in a direction towards the component section (7).

2. The bolt (1) according to claim 1, wherein the bolt (1) comprises a protruding section (10) comprising the first abutment surface (21).

3. The bolt (1) according to claim 1 or 2, wherein the first fastening section (13) is threaded.

4. The bolt (1) according to any one of the preceding claims, wherein the first abutmentsurface (21) is configured to abut against a portion (23) of the structural component (4,4').

5. The bolt (1) according to any one of the preceding claims, wherein the bolt (1) comprisesa second abutment surface (22) arranged between the component section (7) and theplate laminate section (9), and wherein the second abutment surface (22) has a surface normal component (c2) facing in a direction towards the plate laminate section (9).

6. The bolt (1) according to claim 5, wherein the bolt (1) comprises a second fasteningsection (14) configured to receive a second fastening element (15'), and wherein theplate laminate section (9) is arranged between the second fastening section (14) and second abutment surface (22).

7. The bolt (1) according to claim 6, wherein the second fastening section (14) is threaded.

8. The bolt (1) according to any one of the claims 5 - 7, wherein the second abutmentsurface (22) is configured to abut against a portion (25) of the electric plate laminate (3,3').

9. The bolt (1) according to any one of the preceding claims, wherein the componentsection (7) has a diameter (d1) different from the diameter (d2) of the plate laminate section (9).

10. The bolt (1) according to any one of the preceding claims, wherein the componentsection (7) has a diameter (d1) being larger than the diameter (d2) of the plate laminate section (9).

11. An electric machine component (20, 30) comprising an electric plate laminate (3, 3') anda structural component (4, 4') each comprising an opening (8, 8'), wherein the electricmachine component (20, 30) comprises a bolt (1) according to any one of the precedingclaims, and wherein the bolt (1) attaches the electric plate laminate (3, 3') to the structural component (4, 4').

12. The electric machine component (20, 30) according to claim 11, wherein the structuralcomponent (4, 4') comprises a recess (19) enclosing the first abutment surface (21) ofthe bolt (1).

13. The electric machine component (20) according to claim 11 or 12, wherein the electricmachine component (20) is a stator (20) for an electric machine (6), and wherein the electric plate laminate (3) is an electric stator plate laminate (3).

14. The electric machine component (20) according to claim 13, wherein the structural component (4) is a stator housing (4).

15. The electric machine component (30) according to claim 11 or 12, wherein the electricmachine component (30) is a rotor (30) for an electric machine (6), and wherein the electric plate laminate (3') is an electric rotor plate laminate (3').

16. An electric machine (6) comprising an electric machine component (20, 30) according to any one of the claims 11 -15. 18

17. The electric machine (6) according to claim 16, Wherein the electric machine (6) is a vehicle propulsion motor.

18. A vehicle (40) comprising an electric machine (6) according to claim 16 or 17.