• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    The present invention relates to an electric motor (1) for clean room environment applications. The electric motor (1) comprises a housing (2), a stator (3) firmly connected to the housing (2) and a rotor (4) rotatably mounted relative to the housing (2). The rotor (4) has a first end, a second end and an output shaft (6) protruding from the housing (2) at least at the first end of the rotor (4). Rotor or output shaft (6) are sealed by means of a seal relative to the housing (2) or against a further fixed part of the electric motor (1). According to the invention, it is provided that the rotor (4) is rotatably mounted in the housing (2) at the first end with an oil-impregnated sintered bearing (9), wherein the oil-impregnated sintered bearing (9) simultaneously with the rotatable mounting of the rotor (9) the function of the seal takes over.
    公开号:CH710178B1
    申请号:CH01362/15
    申请日:2015-09-21
    公开日:2019-07-31
    发明作者:Wiese Hinrich
    申请人:Maxon Motor Ag；
    IPC主号:
    专利说明:

    The present invention relates to an electric motor for applications in clean room environment according to the preamble of independent claim 1. A generic electric motor has a housing, a fixedly connected to the housing stator and a rotatably mounted relative to the housing rotor. The rotor has a first end, a second end, and an output shaft that protrudes from the housing at least at the first end of the rotor. Furthermore, the rotor or the output shaft is sealed by means of a seal relative to the housing or with respect to a further stationary part of the electric motor.
    In certain manufacturing processes, individual production steps or special laboratory tests, it is necessary to avoid the occurrence of dust or other contaminants as well as possible. In these cases, you use so-called clean rooms. To keep the air in the clean room dust-free, it is usually filtered constantly, so that emerging dust particles are removed continuously. There are also very small cleanrooms that are hermetically sealed against the environment. For example, the housing of a hard disk is also a clean room, which is sealed from the ambient air.
    There are several electric motor operated devices that are used under clean room conditions. For example, the previously mentioned air filter systems for dust filtration are usually operated by an electric motor. Also in measuring systems, with which the clean room quality is detected, partly high-speed electric motors are used, which in turn drive fan systems. Electric motors are also used to drive hard disks.
    The electric motors must be designed such that they do not contaminate the clean room itself. Therefore, i.d.R. specially sealed ball bearings or separate sealing systems used to seal the rotor shaft relative to the electric motor housing. This is the only way to prevent particles from entering the clean room from inside the electric motor. Particles that can lead to contamination of the clean room, in the electric motor in part, for example due to wear, constantly regenerated. This includes the wear that occurs in the bearings themselves. Even with the use of special greases not specially sealed ball bearings are therefore not suitable for clean room applications.
    The special sealing of the bearings is i.d.R. very expensive and therefore expensive. It also goes along with increased friction losses. An electric motor of the generic type is known, for example, from DE 3 818 994 A1. In this electric motor, the rotor shaft is mounted on both sides with a ball bearing, with an elaborate sealing system is additionally provided on each side.
    Object of the present invention is to provide an electric motor of the generic type with a cost-effective, simple and effective seal.
    The object is achieved by the features of independent claim 1. Accordingly, in an electric motor of the generic type then an inventive solution to the problem, when the rotor is rotatably mounted in the housing at the first end with an oil-impregnated sintered bearing, wherein the oil-impregnated Sinter bearing in addition to the rotatable mounting of the rotor simultaneously performs the function of the seal of the electric motor relative to the clean room environment. A sintered bearing is made of a sintered porous material, the pore volume being about 20% to 30% of the total volume. The bearing is provided with an oil impregnation so that the oil contained in the pores can take over the bearing lubrication. The running gap between the shaft and the bearing is kept relatively narrow, so that the oil is drawn into the running gap due to capillary action. As a result, the escape of particles from the interior of the electric motor is effectively prevented or made considerably more difficult. The inventive solution allows a particularly cost-effective sealing of the rotor shaft, since in addition to the sintered bearing no specially provided additional seal is required. The invention is particularly suitable for electric motors with a shaft of small diameter. The invention is also suitable for particularly high-speed electric motors with speeds over 20,000 revolutions per minute.
    Advantageous embodiments of the present invention are the subject of the dependent claims.
    In a first embodiment of the present invention, the rotor is also rotatably mounted in the housing at the second end with an oil-impregnated sintered bearing. This simplifies the production of the electric motor, since one and the same type of bearing can be used both at the rear and at the front end. Compared to a bearing with rolling bearings, for example, with ball bearings, results in this type of storage and the advantage that in both camps fewer particles are generated, which could lead to contamination of the clean room. In this embodiment, it is possible that the shaft also protrudes from the housing at the second end of the rotor. Preferably, however, the housing is closed at the second end.
    Since an oil-impregnated sintered bearing can not provide axial support of the rotor without special precautions, the axial support of the rotor is realized according to a preferred embodiment by means of magnetic forces acting due to the basic design of the electric motor between the rotor and stator. For example, in electronically commutated electric motors with permanent magnet rotor, the rotor interacts with the stator. In this case, magnetic rest positions occur, which not only lead to a centering of the rotor, but counteract to a certain extent, axial deflections. In this embodiment, therefore, no additional
    Devices for axial support necessary. Rather, already existing magnetic forces between the rotor and stator can be used for axial support.
    In order to accommodate larger forces acting in the axial direction of the rotor of the electric motor to record, may alternatively or additionally be provided special magnetic arrangements which counteract a deflection of the rotor in the axial direction.
    In a further embodiment of the present invention, the rotor is rotatably supported at the second end with a ball bearing. As a result, an extremely precise storage can be achieved.
    In a further preferred embodiment of the present invention, the rotor is additionally rotatably mounted at the first end with a ball bearing, wherein the oil-impregnated sintered bearing at the first end binds the outermost bearing. Above all, the oil-soaked sintered bearing performs the function of the seal, while the ball bearing positions the rotor and allows the absorption of axial forces. Particularly preferably, the ball bearing has a more accurate centering than the sintered bearing. As a result, the wear occurring in the sintered bearing is further minimized so that the contamination of the clean room by particles generated in the bearing is further minimized.
    In a further embodiment of the present invention, more than one ball bearing is provided at the first and / or at the second end of the rotor. Preferably, two or more ball bearings can be combined to form a bearing assembly. For example, it may be a strained bearing assembly. In this way, a particularly accurate positioning of the rotor is achieved. In addition, particularly high forces can be absorbed in the axial direction in this embodiment.
    In a further preferred embodiment of the present invention, one of the ball bearings is designed as a fixed bearing. Both the inner and the outer ring of the respective ball bearing are fixed in this embodiment in each case on the rotor or stator. The fixed bearing takes over the axial support of the rotor. With appropriate design or axial positioning of the rotor, the magnetic forces acting between the rotor and stator can be used to bias the fixed bearing. In a preferred embodiment, a ball bearing at the first end of the rotor is designed as a fixed bearing.
    In an embodiment in which two or more ball bearings are used for the rotatable mounting of the rotor in addition to the sintered bearing, at least two ball bearings are preferably braced against each other. For example, a ball bearing may be braced at the first end of the rotor against a ball bearing at the second end of the rotor.
    In a combination of sintered and ball bearings at one end of the rotor, the sintered bearing to avoid static overdetermination is preferably by means of a radially outer peripheral O-ring elastic, but sealingly mounted.
    In a further particularly preferred embodiment of the present invention, the housing of the electric motor is completely sealed to the outside. The housing thus has no gaps or openings through which particles could be released from the interior of the engine to the environment. The single opening of the housing forms the outlet opening for the output shaft of the rotor. This is sealed according to the invention by the oil-impregnated sintered bearing. The complete sealing of the housing relates in particular to the electrical leads of the electric motor. These can be shed, for example. For example, a plastic casting compound is suitable for this purpose. In order to accomplish the complete sealing of the housing in a simple manner, the housing at the second end of the rotor is preferably closed by a lid. The provided at the second end of the rotor bearing for rotatably supporting the rotor is preferably integrated in the lid.
    In a particularly preferred embodiment of the present invention, the electric motor is designed as an electronically commutated electric motor. In the case of electronically commutated electric motors, during operation of the electric motor, particularly few particles are generated in the interior of the electric motor, which could lead to contamination of the clean room. However, the invention is also suitable for DC motors with brush commutation.
    The invention further provides an electric motor operated device for use in clean room environment, in which an electric motor according to the invention is provided as a drive.
    Embodiments of the present invention are explained in more detail below with reference to drawings. It shows:
    1 shows a first embodiment of an inventive electric motor whose rotor is rotatably mounted at one end with an oil-impregnated sintered bearing and at the other end with a ball bearing in the housing,
    2 shows a second embodiment of an inventive electric motor whose rotor is rotatably mounted on both sides with an oil-impregnated sintered bearing in the housing,
    3 shows a further embodiment of an inventive electric motor whose rotor is rotatably mounted at one end with an oil-impregnated sintered bearing and a ball bearing, and at the other end with a ball bearing in the housing, and
    Fig. 4: a further embodiment of an inventive electric motor whose rotor shaft is rotatably mounted in the housing with an oil-impregnated sintered bearing and a plurality of ball bearings.
    For the following statements applies that the same parts are drawn by the same reference numerals. If reference signs are contained in a drawing, which are not discussed in detail in the associated description of the figures, reference is made to preceding or subsequent description of the figures.
    It should be noted that FIGS. 1 to 4 contain only schematic representations of an electric motor.
    Fig. 1 shows a first embodiment of an inventive electric motor 1 for use in a clean room 16. The electric motor 1 has a housing 2, a fixedly connected to the housing 2 stator 3 and a rotatably mounted relative to the housing 4 rotor. In the embodiment shown, the electric motor 1 is designed as an electronically commutated electric motor. The stator windings of the stator 3, not shown in detail, are alternately or sequentially energized by appropriate electronics. The necessary electrical connections 12 are at the point where they enter the housing 2, potted with a potting compound 15, so that the housing has no opening to the clean room 16 at this point. The rotating magnetic field generated in the stator 3 acts on a permanent magnet 5 of the rotor 4 and thereby drives it. The rotor 4 further comprises the output shaft 6 of the electric motor, which protrudes from the housing 2 at the left end 7 of the rotor. For example, an unillustrated fan may be connected to the output shaft. The output shaft 6 of the rotor is rotatably supported on both sides in the housing 2. At the left end 7 for this purpose according to the invention an oil-impregnated sintered bearing 9 is provided between the shaft and the housing, the sintered bearing 9 simultaneously assumes the rotatable mounting and sealing of the motor interior relative to the clean room 16. At the right end 8 of the rotor, the output shaft 6, extending through the hollow cylindrical permanent magnet 5 of the rotor 4 extends, with a ball bearing 11 in a cover 10, with which the housing is closed on the right side, stored. The ball bearing 11 is designed as a fixed bearing. That is, the inner ring of the ball bearing 11 is fixed to the output shaft 6, whereas the outer ring of the ball bearing 11 is fixed to the cover. The axial support of the rotor is thus ensured by the ball bearing 11. The ball bearing 11 is not mechanically biased. Instead, the bias of the bearing is realized by a correspondingly staggered arrangement of stator 3 and permanent magnet 5. However, a mechanical preload of the bearing is also possible.
    Fig. 2 shows another embodiment in which the output shaft 6 of the electric motor projects from both sides of the housing 2. In contrast to the embodiment of FIG. 1, the output shaft is therefore rotatably mounted on the right side with an oil-soaked sintered bearing 9, which is integrated in the cover 10 of the electric motor housing 2. Since the two oil-soaked sintered bearings 9 at the left and right ends of the rotor can not absorb forces acting in the axial direction, additional magnetic arrangements are provided in this embodiment, which prevent axial deflection of the output shaft. In the exemplary embodiment shown, the magnetic arrangements are realized by magnetic disks 13, 14 on the rotor or stator side. The discs 13 and 14 are arranged offset from one another in the axial direction and fix the axial position of the rotor due to magnetic repulsion or attraction. It may be additionally or alternatively, of course, provided a mechanical support in the axial direction. For example, one or more ball bearings can be used for this purpose. The ball bearings can be arranged at one end or at both ends of the rotor and each designed as a single bearing or as a bearing assembly, consisting of two or more ball bearings.
    In Fig. 3, a further embodiment is shown, in which, in contrast to the embodiment of FIG. 1 at the left end 7 of the rotor in addition to the oil-soaked sintered bearing 9, a ball bearing 11 is provided. The sintered bearing 9 takes over in this embodiment, in addition to the rotatable mounting above all the sealing of the electric motor housing 2 with respect to the clean room 16. The adjacently arranged ball bearing 11 ensures a slightly more accurate centering and therefore causes the sintered bearing 9 undergoes a low load. As a result, the wear that occurs in the sintered bearing 9 is minimized. In this way, the contamination of the clean room 16 by particles, which may arise due to wear in the warehouse, further minimized. The ball bearing on the left side, for example, designed as a fixed bearing and be biased accordingly. Alternatively, the ball bearing 11 may be braced on the left side relative to the ball bearing 11 on the right side.
    Fig. 4 shows a similar embodiment in which both the left end 7 and the right end 8 of the rotor are each provided two combined to form a bearing assembly ball bearings 11 are provided. In this embodiment, especially when the ball bearings are braced against each other, particularly large loads acting in the axial direction can be accommodated.
    权利要求:
    Claims (15)
    [1]
    Electric motor (1) for applications in a clean room environment (16), comprising a housing (2), a stator (3) fixedly connected to the housing (2) and a rotor (4) rotatably mounted relative to the housing (2), wherein the rotor (4) has a first end (7), a second end (8) and an output shaft (6) protruding from the housing (2) at least at the first end (7) of the rotor (4), and wherein the inside of the electric motor (1) is sealed from the clean room environment (16) by means of a seal arranged between the rotor (4) or the output shaft (6) and the housing (2) or another fixed part of the electric motor (1) , characterized in that the rotor (4) at the first end (7) with an oil-impregnated sintered bearing (9) is rotatably mounted in the housing (2), wherein the oil-impregnated sintered bearing (9) in addition to the rotatable mounting of the rotor (4) at the same time Function of the seal takes over.
    [2]
    2. Electric motor (1) according to claim 1, characterized in that the rotor at the second end (8) is also rotatably mounted in the housing (2) with an oil-impregnated sintered bearing (9).
    [3]
    3. Electric motor (1) according to claim 2, characterized in that the axial support of the rotor (4) by means of magnetic forces acting due to the design of the electric motor (1) between the rotor (4) and stator (3) is realized.
    [4]
    4. Electric motor (1) according to claim 2 or 3, characterized in that for the axial support of the rotor (4) special magnetic arrangements (13,14) are provided which counteract a deflection of the rotor (4) in the axial direction.
    [5]
    5. Electric motor (1) according to claim 1, characterized in that the rotor (4) at the second end (8) with a ball bearing (11) is rotatably mounted.
    [6]
    6. Electric motor (1) according to claim 1 or 5, characterized in that the rotor (4) at the first end (7) is additionally rotatably mounted with a ball bearing (11), wherein the oil-impregnated sintered bearing (9) at the first end (7 ) forms the outermost bearing towards the clean room environment (16).
    [7]
    7. Electric motor (1) according to claim 5 or 6, characterized in that at the first and / or second end (7, 8) more than one ball bearing (11) is provided.
    [8]
    8. Electric motor (1) according to claim 7, characterized in that two or more ball bearings (11) are combined to form a bearing assembly.
    [9]
    9. Electric motor (1) according to one of claims 5 to 8, characterized in that a ball bearing (11) is designed as a fixed bearing.
    [10]
    10. Electric motor (1) according to claim 7, characterized in that a ball bearing (11) at the first end (7) is designed as a fixed bearing.
    [11]
    11. Electric motor (1) according to one of claims 6 to 8, characterized in that at least two ball bearings (11) are braced against each other.
    [12]
    12. Electric motor (1) according to one of claims 1 to 11, characterized in that the housing (2) is completely sealed to the outside by the housing (2) except an outlet opening for the output shaft (6) of the electric motor (1), which is sealed by the oil-soaked sintered bearing (9), has no gaps or openings through which particles could be released from the interior of the electric motor (1) to the clean-room environment (16).
    [13]
    13. Electric motor (1) according to claim 12, characterized in that the housing (2) at the second end (8) of the rotor (4) by a cover (10) is closed.
    [14]
    14. Electric motor (1) according to one of claims 1 to 13, characterized in that the electric motor (1) is designed as an electronically commutated electric motor (1).
    [15]
    15. An electric motor operated device for use in clean room environment (16), characterized in that the device comprises an electric motor (1) according to one of claims 1 to 14 as a drive.
    类似技术:
    公开号 | 公开日 | 专利标题
    DE3839731C2|1993-01-14|
    DE4201786C2|1995-05-11|Electric motor, in particular for use in film cameras
    DE3404208A1|1985-08-08|MAGNETIC DISK STORAGE WITH A PACK OF DISKS STORED IN A SPRINGLY HOUSING
    DE102013111657A1|2014-04-24|Brushed rotary device
    DE112013006949T5|2015-12-31|Electric rotary machine
    DE3041274A1|1982-02-18|ENCLOSED DISC DRIVE UNIT
    EP2060794B1|2016-05-04|Vacuum pump with lubricant pump
    DE3235866A1|1983-05-11|ENGINE
    DE102019206333A1|2020-11-05|Hydraulic power pack
    DE2129796C3|1981-11-19|Open-end spinning device with rotor
    DE102015109236A1|2015-12-24|Turntable assembly with cover
    DE10247310A1|2004-04-22|Air-cooled electrical machine e.g. electric locomotive motor, uses single cooling fan for providing primary and secondary cooling air flows
    DE10361229B4|2012-01-26|Spindle motor with storage system
    DE102013219186A1|2015-03-26|Electric machine and connection unit for electric machine.
    CH710178B1|2019-07-31|Electric motor for applications in cleanroom environment.
    DE69924597T2|2006-03-02|DYNAMIC GROOVE BEARING WITH POROUS LUBRICANT CONTAINER
    DE102008062679A1|2010-06-24|Fluid dynamic storage system
    DE102017005812A1|2017-12-28|ELECTRIC MOTOR AND ELECTRIC MOTOR EQUIPPED TOOL MACHINE
    EP2199632B1|2013-09-18|Bearing assembly with porous elements in ring segments
    DE102008033361A1|2009-05-28|Spindle motor for operating hard disk drive and fan, has axial section formed between outer wall of hub and inner wall of base plate or between outer wall of hub and inner wall of laminated stator core
    EP3225448A1|2017-10-04|Wheel hub drive assembly
    DE3430479A1|1985-03-07|BEARING ARRANGEMENT WITH INTEGRATED FERROFLUID SEAL
    DE102007028905B3|2008-12-11|Bearing device for non-contact mounting of a rotor against a stator
    DE19928141A1|2000-12-21|Sealing arrangement
    EP3196471A1|2017-07-26|Monolithic permanent magnet, permanent magnet bearing, vacuum pump and method for producing a monolithic permanent magnet
    同族专利:
    公开号 | 公开日
    DE102014014123A1|2016-03-24|
    CH710178A2|2016-03-31|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    CH151012A|1930-03-07|1931-11-30|Jung Karl|Storage of precisely running spindles using roller bearings.|
    GB2075240B|1980-03-05|1985-03-13|Papst Motoren Kg|Disc storage drive|
    DE3524360A1|1984-08-07|1986-02-20|VEB Kombinat Robotron, DDR 8010 Dresden|Silenced mounting of the shaft in stepper motors|
    DE3818994A1|1987-06-02|1988-12-22|Papst Motoren Gmbh & Co Kg|Disc store drive|
    JP2001027231A|1999-07-15|2001-01-30|Minebea Co Ltd|Bearing structure for flat motor|
    DE10102012A1|2001-01-18|2002-08-01|Bosch Gmbh Robert|bearings|
    DE10144653B4|2001-09-11|2006-05-11|Ate Antriebstechnik Und Entwicklungs Gmbh|Permanently energized electromechanical machine for operation in liquids and gases|
    DE10221843B4|2002-05-16|2004-12-30|Minebea Co., Ltd.|Electric motor for use as a pump motor and pump|
    DE102012206189A1|2012-04-16|2013-10-17|Robert Bosch Gmbh|Electric machine and method for operating an electrical machine|
    DE102013015576A1|2012-09-21|2014-03-27|Minebea Co., Ltd.|Spindle motor for driving fan, has electromagnetic drive unit for rotating the rotatable motor component, and axial force generating unit for generating an aerodynamic force to fan wheel|CN111348165A|2020-03-25|2020-06-30|中山大学|Underwater navigation power device|
    法律状态:
    优先权:
    申请号 | 申请日 | 专利标题
    DE102014014123.3A|DE102014014123A1|2014-09-22|2014-09-22|Electric motor for applications in cleanroom environment|
    [返回顶部]