Facilitating the assembly and dissassembly of a machine

Abstract

The tool is for the mounting or removal of one component which is at least partially within or around another component when fixed to the machine by fixing means screwed into threaded recesses 20 on t

Description

FIELD OF THE INVENTION The field of the invention relates to facilitating the assembly and / or disassembly 5 of a machine such as a vacuum pump, and in particular to facilitating the mounting or removal of a component that fits at least partially within or around another component. BACKGROUND 10 Mounting or removing components on a machine such as a vacuum pump, particularly where they have magnetic parts and are mounted at least partially around or within another component can be difficult. Particularly where the gaps between the components are small, such that they need to be accurately aligned during the mounting or removal process to inhibit any contact between the 15 components. Embodiments seek to facilitate such processes. SUMMARY 20 A first aspect provides a tool for facilitating the assembly or disassembly of a machine by facilitating the mounting or removal of one component, said one component being at least partially within or around another component of said machine when mounted on said machine and being fixed to said machine by fixing means screwed into threaded recesses on said machine, said threaded 25 recesses comprising: an opening for receiving said fixing means, a cylindrical side wall portion comprising a thread and a tapered end portion; wherein said tool comprises: at least two elongate guide members, each comprising: an end portion configured to be received within a corresponding one of said threaded recesses; and an elongate guide portion extending from said end 30 portion; wherein said end portion comprises a tapered end, a narrower cylindrical portion extending from said tapered end and a wider threaded cylindrical portion, said wider threaded cylindrical portion being less than 25% of a length of said end portion. Guides may be used to facilitate the mounting or removal of a component of a 5 machine, particularly where it is at least partially nested within or around another component and where the tolerances are small, such that to avoid the components contacting each other, the component being removed needs to follow a straight trajectory until it is clear of the at least partially nested other component. Embodiments provide such guides that are configured to be io mounted within threaded recesses on the machine. These recesses may be for receiving fixing means for fixing the component to the machine. The guides are configured with a tapered end that allows the guide to centre itself automatically within the recess, by aligning with the tapered end, or drilling cone, of the threaded recess. Given the requirement for careful alignment of the components 15 this ability to self centre is important. Furthermore, the guides, have a threaded portion of between 1 and 7 turns and a non-threaded portion that is narrower, that is it has a reduced diameter compared to the threaded portion. The narrower non-threaded portion lies between the tapered end and the threaded portion, and this arrangement allows the guide to be inserted quickly into the recess and 20 secured in position with a few turns. As the guide extends for the length of the threaded recess and is centred by the tapered end, it is aligned, despite only having a few turns of the threaded portion engaged with the threaded recess. In some embodiments, said tapered end of said elongate guide member is 25 hemispherical. A hemispherical end portion is easy to machine and naturally aligns within a tapered recess. In other embodiments, said tapered end of said elongate guide member is conical or frustoconical. An alternative shape for the tapered end may be a conical or 30 frustoconical shape which may be appropriate where the tapered end of the recess it is also conical or frustoconical. ln some embodiments, said wider threaded portion of said elongate member is configured to engage with said thread of said threaded recess for between 1 and 5 turns, preferably 1 and 3 turns. The configuration of the guide member with the narrower portion that fits within the recess and the tapered end that self centres 5 allows the guide to be aligned and held in place with only a few turns of the cooperating threads engaged, allowing the guide to be inserted and removed effectively and efficiently. In some embodiments, at least a portion of a surface of said elongate guide io portion is roughened. In order to facilitate the manipulation and turning of the elongate guide member then a portion of the surface that is grasped by a user may be roughened in some embodiments by using knurling. A length of said end portion may be configured such that when said thread of 15 said elongate member is engaged with said thread on said threaded recess, said tapered end of said elongate member is received within said tapered end of said threaded recess and centres said elongate member within said recess. The elongate guide portion of said elongate guide member may be configured to 20 extend beyond said one and said another component when received within said threaded recess. The elongate guide member may extend beyond the another component allowing it to be removed once the one component is in position and allowing the one component to be guided by the elongate guide from a starting position where it is not nested within or around the another component. 25 Although, in theory two elongate guide members could be used, it may be advantageous to have at least three elongate guide members to more securely guide and align the one component. 30 A further aspect provides a method of mounting one component on a machine using the tool of a first aspect, said one component being at least partially within or around another component of said machine when mounted thereon, said method comprising: attaching at least two of said elongate guide members of said tool to said machine, by pushing said narrower cylindrical end portion of each of said at least 5 two elongate guide members into corresponding at least two threaded recesses on said machine until said thread of said elongate guide members contacts said threaded recess opening; for each of said at least two elongate guide members, turning said elongate guide member such that said threaded portion of said elongate guide 10 member engages with said threaded recess and screws into said threaded recess until said tapered end of said elongate member is received within a tapered end of said threaded recess, said tapered end of said elongate member centring said elongate member within said recess; sliding said one component guided by said elongate guide portions of said 15 elongate guide members and into position on said machine; unscrewing said at least two elongate guide members and removing said at least two elongate guide members from said threaded recesses; and screwing fixing means into said threaded recesses to attach said one component to said machine. 20 The method may comprise part of a method for assembling the machine or it may comprise part of a method of reassembling the machine following servicing or repair. 25 A yet further aspect provides a method of removing one component from a machine, said one component being at least partially within or around another component of said machine, the method using the tool of a first aspect, said method comprising: unscrewing and removing fixing means attaching said one component to 30 said machine, said fixing means being unscrewed from threaded recesses on said machine; for each of said at least two elongate members of said tool: pushing said narrower cylindrical end portion into one of said threaded recesses on said machine until said thread of said elongate guide member contacts said threaded recess opening; turning said elongate guide member such that said threaded portion 5 of said elongate guide member engages with said threaded recess and screws into said threaded recess until said tapered end of said elongate member is received within a tapered end of said threaded recess, said tapered end of said elongate member centring said elongate member within said recess; 10 removing said one component by sliding said one component guided by said elongate guide portions of said elongate guide members. The method may comprise part of a method of disassembling a machine, which may be performed during servicing of the machine. 15 In some embodiments, said step of turning comprises engaging between 1 and 5 turns, preferably between 1 and 3 turns, of said threaded recess with the threaded end portion of said elongate guide members. 20 In some embodiments, at least one of said one or said another component comprises at least one magnetic element. Where the one or another component or both comprise magnetic elements then guiding them into or out of position is complicated by the forces exerted between 25 the components which can cause them to become misaligned and to impact each other thereby causing damage. The guide members help inhibit this and make the mounting or the dismounting of the component easier, safer less prone to causing damage. 30 Although, the one component and the other component may comprise a number of different machine components in some embodiments they comprise a motor stator, and a motor rotor. ln some embodiments, said motor rotor and stator comprises a motor of a pump, in some cases a vacuum pump. 5 In some embodiments, said method comprises a part of a method of servicing said machine. Further particular and preferred aspects are set out in the accompanying independent and dependent claims. Features of the dependent claims may be 10 combined with features of the independent claims as appropriate, and in combinations other than those explicitly set out in the claims. Where an apparatus feature is described as being operable to provide a function, it will be appreciated that this includes an apparatus feature which provides that 15 function or which is adapted or configured to provide that function. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be described further, with reference to the accompanying drawings, in which: 20 Figure 1 shows a self-centering guide according to an embodiment; Figure 2 shows a vacuum pump with motor rotor and with the motor stator removed; Figure 3 shows the vacuum pump of Figure 2 with the motor stator about to be mounted on the vacuum pump; 25 Figure 4 shows steps in a method of removing the motor stator from a pump; and Figure 5 shows steps in a method for mounting a motor stator onto a pump during a pump assembly or servicing. DESCRIPTION OF THE EMBODIMENTS 30 Before discussing the embodiments in any more detail, first an overview will be provided. Embodiments relate to a guide member for helping align a machine component during mounting or removing of that component to or from the machine, in particular a component that is at least partially nested around or within another component of the machine and which may comprise magnetic elements. The 5 guide means is an elongate element arranged to be mounted within recesses on the machine, which recesses may be configured to receive fixing means to fix the component to the machine. The elongate members are arranged to be received within the recesses and to engage with a few turns of the threaded portion of the recess. They extend beyond the machine and allow the component that is to be 10 mounted to be slid along the guide and thus, inhibit it from contacting the nested component even where there is substantial magnetic forces pulling the two together. Figure 1 shows an elongate guide member 10 according to an embodiment. 15 Elongate guide member 10 comprises an elongate guide portion 19 which in this embodiment is cylindrical and has a tapered remote end 11 for ease of insertion into an aperture on the component to be mounted. The elongate guide member 10 is configured to be mounted within a threaded recess 20 on the machine which threaded recess 20 has a tapered end 22 which may be a drilling cone. 20 The elongate guide member has an end portion 12 configured to be received within the threaded recess 20, which end portion has a threaded portion 18 and a narrower portion 16 which ends in a tapered end 14. The elongate guide member is sized such that the end portion 16 has a smaller diameter than the diameter of the recess 20 so that it can slide into place and when the threaded 25 portion 18 contacts the thread at the opening of the recess 20 a few turns will screw it into position and the tapered end 14 will fit within the tapered end 22 of the guide. The tapered end 14 will self-align the elongate member within the recess and only a few turns of the thread are used to hold it in position. In this way, a self-centred guide that is quick and easy to mount within a recess is 30 provided. Figure 2 schematically shows a vacuum pump 40 with a motor rotor 42 extending from the vacuum pump. The motor stator has not been mounted on the vacuum pump at this point and the vacuum pump 40 has recesses 20 for receiving fixing means to fix the stator in position. In this embodiment three recesses are shown 5 but in other embodiments there may be more. These recesses that are configured to receive the fixing means to fix the motor stator in position are reused for receiving the guide means during assembly or disassembly of the motor. io Figure 3 shows schematically the vacuum pump 40 with elongate guide members 10 placed within three recesses 22 for receiving fixing means. Motor stator 44 is shown schematically ready to be mounted on the vacuum pump 40. The guides 10 will extend through holes (not shown) on motor stator 44 which holes are configured for receiving the screw fixing means for fixing the stator to the vacuum 15 pump 40. The holes may be on flanges on the edge of the motor stator 44. In this way, the motor stator 44 can be guided by the elongate guide members as it is slid into position and in this way it is aligned with the motor rotor during the trajectory and the guides impede any lateral movement that might result in contact between the stator 44 and rotor 42, even where there is significant 20 magnetic forces and low clearances between the two. Figure 4 shows steps in a method of removing a motor stator from a vacuum pump according to an embodiment. Such a removal of the stator may be done during repair or servicing of the vacuum pump. Although, a motor stator is 25 provided as an example, other components can also be removed from a machine using this method. In an initial step S10 the screws that are attaching the motor stator to the pump are unscrewed and removed. At step S20 three guide members are inserted into 30 a corresponding three threaded recesses from which the screws were removed until the thread on the guide member reaches the recess opening. At this point step S30 is performed, and the guide member is turned through between 1 and 7 turns so that the thread on the guide engages with a portion of the thread at the opening of the recess and the guide is screwed into position and the tapered end of the guide member moves within the tapered end of the recess. 5 This acts automatically to centre the guide within the recess. At step S40 the motor stator is removed by sliding it away from the vacuum pump guided by the guide members. Figure 5 shows steps in a method of assembling a motor stator of a vacuum io pump according to an embodiment. This step may be performed during the assembly of the vacuum pump or during the reassembly following servicing. At step S100 three guide members are attached to the vacuum pump by pushing them into three threaded recesses on the vacuum pump until the thread of the guide members contacts the threaded recess opening. At this point step S110 is 15 performed and the three guide members are turned such that the threaded portion of the guide member engages with the thread of the threaded recess and screws the guide members into the threaded recess until the tapered end of the guide member contacts the tapered end of the recess. This will take between 1 and 7 turns, preferably between 1 and 3. In some cases, the guide member may 20 be turned by grasping it on a roughened portion of the outer surface which may have been roughened by knurling. At step S120 the motor stator is slid into position guided by the elongated guide portions of the guide members. At step S130 the guide members are unscrewed 25 from the threaded recesses to remove the guide members, and then at step S140, screw fixing means are inserted into the holes on the motor stator and screwed into the threaded recesses on the vacuum pump to attach the motor stator to the pump. 30 In summary embodiments may provide elongate guide members that can be simply machined from for example a rectified steel bar, leading to low manufacturing costs. The elongate guide members are designed so that their insertion and removal from the machine can be done by quick manual screwing with a few turns of the thread being engaged. The tapered end, allows for effective centering on the 5 drilling cone in the recess. The guide is thereby aligned to be concentric with the internal thread axis of the recess, The tool is easy to use in machine production and may also be provided for use in the servicing of machines. It may be used for vacuum pumps, but may also be 10 used for different types of machines and can easily be manufactured in different sizes. The guide may be provided with a roughened surface to improve grip. Although illustrative embodiments of the invention have been disclosed in detail herein, with reference to the accompanying drawings, it is understood that the 15 invention is not limited to the precise embodiment and that various changes and modifications can be effected therein by one skilled in the art without departing from the scope of the invention as defined by the appended claims and their equivalents. REFERENCE SIGNS 10 elongate guide member 11 remote tapered end 12 end portion 5 14 tapered end 16 narrower cylindrical portion 17 knurled surface 18 threaded portion 19 guide portion io 20 threaded recess 22 tapered end 40 vacuum pump 42 motor rotor 44 motor stator 15

Claims

1. A tool for facilitating the assembly or disassembly of a machine by facilitating the mounting or removal of one component, said one component being 5 at least partially within or around another component of said machine when mounted on the machine and being fixed to said machine by fixing means screwed into threaded recesses on said machine, said threaded recesses comprising an opening for receiving said fixing means, a cylindrical side wall portion comprising a thread and a tapered end portion; wherein said toolio comprises:at least two elongate guide members, each comprising:an end portion configured to be received within a corresponding one of said threaded recesses; andan elongate guide portion extending from said end portion; wherein 15 said end portion comprises a tapered end, a narrower cylindricalportion extending from said tapered end and a wider threaded cylindrical portion, the thread of the wider threaded cylindrical portion comprising between 1 and 7 turns.20 2. A tool according to claim 1, wherein said tapered end of said elongateguide member is hemispherical.

3. A tool according to claim 1, wherein said tapered end of said elongate guide member is conical or frustoconical.

254. A tool according to any preceding claim, wherein said wider threaded portion of said elongate member is configured to engage with said thread of said threaded recess for between 1 and 5 turns, preferably 1 and 3 turns.30 5. A tool according to any preceding claim, wherein at least a portion of asurface of said elongate guide portion is roughened.

6. A tool according to any preceding claim, wherein a length of said end portion is such that when said thread of said elongate member is engaged with said thread on said threaded recess, said tapered end of said elongate member is received within said tapered end of said threaded recess and centres said5 elongate member within said recess.

7. A tool according to any preceding claim, wherein said elongate guide portion of said elongate guide member is configured to extend beyond said one and said another component when received within said threaded recess.io8. A tool according to any preceding claim, said tool comprising at least three elongate members.

9. A method of mounting one component on a machine using the tool of any 15 one of claims 1 to 8, said one component being at least partially within or around another component of said machine when mounted thereon, said method comprising:attaching at least two of said elongate guide members of said tool to said machine, by pushing said narrower cylindrical end portion of each of said at least20 two elongate guide members into corresponding at least two threaded recesses on said machine until said thread of said elongate guide members contacts said threaded recess opening;for each of said at least two elongate guide members, turning said elongate guide member such that said threaded portion of said elongate guide 25 member engages with said threaded recess and screws into said threaded recess until said tapered end of said elongate member is received within a tapered end of said threaded recess, said tapered end of said elongate member centring said elongate member within said recess;sliding said one component guided by said elongate guide portions of said 30 elongate guide members and into position on said machine;unscrewing said at least two elongate guide members and removing said at least two elongate guide members from said threaded recesses; andscrewing fixing means into said threaded recesses to attach said one component to said machine.

10. A method of removing one component from a machine, said one5 component being at least partially within or around another component of said machine, the method using the tool of any one of claims 1 to 8, said method comprising:unscrewing and removing fixing means attaching said one component to said machine, said fixing means being unscrewed from threaded recesses on io said machine;for each of said at least two elongate members of said tool:pushing said narrower cylindrical end portion into one of said threaded recesses on said machine until said thread of said elongate guide member contacts said threaded recess opening;15 turning said elongate guide member such that said threaded portionof said elongate guide member engages with said threaded recess and screws into said threaded recess until said tapered end of said elongate member is received within a tapered end of said threaded recess, said tapered end of said elongate member centring said elongate member20 within said recess;removing said one component by sliding said one component guided by said elongate guide portions of said elongate guide members.

11. A method according to claim 9 or 10, wherein said step of turning25 comprises engaging between 1 and 5 turns, preferably between 1 and 3, of said threaded recess with the threaded end portion of said elongate members.

12. A method according to any one of claims 9 to 11, wherein at least one of said one or said another component comprises at least one magnetic element.

13. A method according to any one of claims 9 to 12, wherein said one component comprises a motor stator, and said another component comprises a motor rotor.5 14. A method according to claim 13, wherein said motor rotor and statorcomprises a motor of a pump, in some cases a vacuum pump.

15. A method according to any one of claims 9 to 14 ,wherein said method comprises a part of a method of servicing said machine.io

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