Sealed robot drive unit

Abstract

A conveying device having a separation wall between a stator and a rotor that minimizes the air gap between the stator and the rotor. [Solution] A conveying device comprising a housing, a drive unit attached to the housing, and at least one conveying arm connected to the drive unit, wherein the drive unit includes at least one rotor (101) having at least one salient pole of a magnetically permeable material and positioned in an isolated environment, at least one stator (206) having at least one salient pole with a corresponding coil unit and positioned outside the isolated environment, and at least one sealing unit configured to isolate the isolated environment and integral with the at least one stator (206), wherein at least one salient pole of the at least one stator (206) and at least one salient pole of the rotor (101) form a closed magnetic flux circuit between the at least one rotor (101) and the at least one stator (206).

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application is a regular application claiming the benefit of U.S. Provisional Patent Application No. 61 / 903,813, filed on November 13, 2013, the entire disclosure of which is incorporated herein by reference.

[0002] [Technical Field] Exemplary embodiments generally relate to robot drives, and more particularly, to hermetic robot drives.

Background Art

[0003] Generally, for example, existing direct - drive technologies that use permanent - magnet motors or variable - reluctance motors, such as for optical encoders for startup and position measurement, exhibit significant limitations when, for example, the magnets, bonded parts, seals, and corrosive materials of the direct - drive device are exposed to ultra - high vacuum and / or aggressive and corrosive environments. For example, a "can - seal" is generally used to limit the exposure of the magnets, bonded parts, seals, and corrosive materials of the direct - drive device.

[0004] The can shield generally isolates the rotor of a motor from the corresponding stator of the motor by a hermetically sealed non-magnetic wall or "can", also known as a "partition wall". The can shield generally uses a non-magnetic vacuum isolation wall located between the rotor and the stator of a given motor actuator. Thereby, magnetic flux can flow between the rotor and the stator across the isolation wall. As a result, the stator can be located completely outside the sealed environment. This enables the implementation of a substantially clean and reliable motor startup in applications such as vacuum robot drive devices used in semiconductor applications. A limitation of such a can shield is that the size of the air gap between the magnetic poles of the rotor and the stator may be limited by the thickness of the isolation wall. For example, adding a runout tolerance to the thickness of the isolation wall generally imposes a constraint on the minimum achievable air gap between the rotor and the stator. To improve the efficiency of the motor, the gap between the rotor and the stator should be minimized, but when the environment isolated by the seal or can shield is exposed to high vacuum or ultra-high vacuum, the isolation wall must be large enough to provide sufficient structural integrity to substantially prevent excessive deflection (i.e., deflection of the isolation may interfere with the operation of the motor). As a result, compared to a solution for a robot drive unit without an isolation wall crossing the rotor / stator air gap, the air gap between the stator and the rotor needs to be larger, so the efficiency of the motor can be significantly reduced.

[0005] In one aspect, "dynamic sealing" can generally be used to isolate substantially the entire motor from the sealed environment. The dynamic sealing can be a seal that allows a portion of the driven shaft of the motor to operate within the isolation environment. The dynamic sealing can be achieved in a number of ways, including, for example, lip seals and magnetic fluid seals. However, these dynamic seals can have the potential for sources of particle contamination (e.g., from seal wear and cracks), high friction between stationary and moving members, limited lifespan, and the risk of leakage between the sealed environment and, for example, the atmospheric environment outside the sealed environment.

[0006] As another solution regarding the sealing drive unit, there is a stator coil positioned within the sealed environment. However, in applications where the sealed environment operates in a high vacuum, the stator coil may not only release undesirable compounds but also risk overheating. As a result, the above-described sealing solutions may be expensive and / or difficult to implement.

[0007] In another aspect, a direct drive motor such as a variable reluctance motor or a switched reluctance motor may utilize a solid rotor. However, a conventional solid rotor may have an inherent problem of core loss due to the influence of eddy currents resulting from, for example, the rate of change of phase current in the use of a switched reluctance motor. Another known solution for core loss is to utilize a material containing metal ferromagnetic particles together with non-conductive particles that attempt to maintain good magnetic flux as compared to either a solid rotor or a laminated rotor.

Summary of the Invention

[0008] It is advantageous to have a partition wall between the stator and the rotor that minimizes the air gap between them. Also, it is advantageous to have a vacuum-compatible laminated rotor that provides improved magnetic efficiency and / or precise position control.

[0009] The foregoing aspects and other features of the disclosed embodiments are described in the following description with reference to the accompanying drawings.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0011] Referring to FIGS. 1A - 1D, a schematic diagram of a substrate processing apparatus or tool incorporating aspects of the disclosed embodiments as further disclosed herein is shown. The aspects of the disclosed embodiments are described with reference to the drawings, but it should be understood that the aspects of the disclosed embodiments can be embodied in many forms. Additionally, elements or materials of any suitable size, shape, or type can be used.

[0012] Referring to FIGS. 1A and 1B, for example, a processing apparatus such as semiconductor tool station 11090 is shown in accordance with aspects of the disclosed embodiments. Although semiconductor tools are shown in the figures, aspects of the disclosed embodiments described herein are applicable to any tool station or application that uses a robotic manipulator. In this example, tool 11090 is shown as a cluster tool, but aspects of the disclosed embodiments may be applied to any tool station, such as a linear tool station as shown in FIGS. 1C and 1D, such as that described in U.S. Patent No. 8,398,355, entitled "Linearly Distributed Semiconductor Workpiece Processing Tool," issued on March 19, 2013, the entire disclosure of which is incorporated herein by reference. Tool station 11090 generally includes an atmospheric front end 11000, a vacuum load lock 11010, and a vacuum back end 11020. In other aspects, the tool station may have any suitable configuration. Each component of the front end 11000, load lock 11010, and back end 11020 may be connected to a control device 11091 that may be part of any suitable control architecture, such as clustered architecture control. The control system may be a closed-loop control device having a main control device, a cluster control device, and an autonomous remote control device, such as that described in U.S. Patent No. 7,904,182, entitled "Scalable Motion Control System," issued on March 8, 2011, the entire disclosure of which is incorporated herein by reference. In other aspects, any suitable control device and / or control system may be utilized.

[0013] In one aspect, the front end 11000 generally includes a load port module 11005 and a mini-environment 11060 such as, for example, an equipment front end module (EFEM). The load port module 11005 may be a 300 mm load port, a front-opening or bottom-opening box / pod, and a box opener / loader tool standard (BOLTS) interface compliant with SEMI standards E15.1, E47.1, E62, E19.5, or E1.9 for cassettes. In other aspects, the load port module may be configured as a 200 mm wafer interface or as any other suitable substrate interface, such as, for example, a flat panel for large or small wafers or flat panel displays. Although two load port modules are shown in FIG. 1A, in other aspects, any suitable number of load port modules may be incorporated into the front end 11000. The load port module 11005 may be configured to receive a substrate carrier or cassette 11050 from an overhead transport system, an automated guided vehicle, a manned transport vehicle, a rail-type transport vehicle, or any other suitable transport means. The load port module 11005 may be connected to the mini-environment 11060 through a load port 11040. The load port 11040 may enable the passage of substrates between the substrate cassette 11050 and the mini-environment 11060. The mini-environment 11060 generally includes any suitable transfer robot 11013 that may incorporate one or more aspects of the disclosed embodiments described herein. In one aspect, the robot 11013 may be, for example, a walking-mounted robot such as that described in U.S. Patent No. 6,002,840, the entire disclosure of which is incorporated herein by reference. The mini-environment 11060 may provide a controlled clean zone for substrate transfer between multiple load port modules.

[0014] The vacuum load lock 11010 is located between the mini-environment 11060 and the back end 11020 and may be connected to the mini-environment 11060 and the back end 11020. As used herein, the term "vacuum" may mean a high vacuum such as 10 -5 Torr or less in which the substrate is processed. The load lock 11010 generally includes an atmosphere and a vacuum slot valve. The slot valve is used to evacuate the load lock after loading the substrate from the atmosphere front end and to provide environmental isolation for maintaining the vacuum in the transfer chamber when venting the lock with an inert gas such as nitrogen. The load lock 11010 may include an aligner 11011 for aligning the reference of the substrate to a desired position for processing. In other embodiments, the vacuum load lock may be installed at any suitable location of the processing apparatus and may have any suitable configuration.

[0015] The vacuum backend 11020 generally includes a transfer chamber 11025, one or more processing stations 11030, and any suitable transfer robot 11014 that may include one or more aspects of the disclosed embodiments described herein. The transfer robot 11014, which is described below, may be located within the transfer chamber 11025 to transfer substrates between the load lock 11010 and the various processing stations 11030. The processing stations 11030 may operate on substrates to form electrical circuits or other desirable structures thereon through various film deposition, etching, or other types of processing. Exemplary processing includes, but is not limited to, plasma etching or other etching processes, chemical vapor deposition (CVD), plasma vapor deposition (PVD), implantation such as ion implantation, measurement, rapid thermal processing (RTP), dry flake atomic layer deposition (ALD), oxidation / diffusion, nitride formation, vacuum lithography, epitaxy (EPI), wire bonding, and evaporation, thin film processing using a vacuum, or thin film processing using other vacuum pressures. The processing stations 11030 are connected to the transfer chamber 11025 to enable substrates to pass from the transfer chamber 11025 to the processing stations 11030 or vice versa.

[0016] Next, referring to FIG. 1C, a schematic plan view of a linear substrate processing system 2010 is shown in which a tool interface section 2012 generally faces (e.g., inwardly) the longitudinal axis X of the transfer chamber 3018, but is offset from the longitudinal axis X of the transfer chamber 3018, and the tool interface section 2012 is attached to the transfer chamber module 3018. The transfer chamber module 3018 may be extended in any suitable direction by attaching other transfer chamber modules 3018A, 3018I, 3018J to the interface sections 2050, 2060, 2070, as described in U.S. Pat. No. 8,398,355, which is hereby incorporated by reference. Each transfer chamber module 3018, 3019A, 3018I, 3018J includes any suitable substrate transfer section 2080, as described herein, for transferring substrates throughout the processing system 2010 and, for example, in and out of the processing module PM, and may include one or more aspects of the disclosed embodiments. As will be appreciated, each chamber module may be capable of maintaining an isolated or controlled atmosphere (e.g., N2, clean air, vacuum).

[0017] Referring to FIG. 1D, a schematic elevation view of an exemplary processing tool 410 along the longitudinal axis X of the linear transfer chamber 416 is shown. In the aspect of the disclosed embodiment shown in FIG. 1D, the tool interface section 12 may typically be connected to the transfer chamber 416. In this aspect, the interface section 12 may define one end of the tool transfer chamber 416. As seen in FIG. 1D, the transfer chamber 416 may have, for example, another workpiece entry / exit station 412 from the connection station 12 to the opposite end. In other aspects, other entry / exit stations for inserting / removing the workpiece from the transfer chamber may be provided. In one aspect, the interface section 12 and the entry / exit station 412 may enable loading and unloading of the workpiece from the tool. In other aspects, the workpiece may be loaded onto the tool from one end and removed from the other end. In one aspect, the transfer chamber 416 may have one or more transfer chamber modules 18B, 18i. Each chamber module may be capable of maintaining an isolated or controlled atmosphere (e.g., N2, clean air, vacuum). As already described, the configuration / arrangement of the transfer chamber modules 18B, 18i, load lock modules 56A, 56B, and workpiece stations forming the transfer chamber 416 shown in FIG. 1D is merely exemplary, and in other aspects, the transfer chamber may have more or fewer modules arranged in any desired module arrangement. In the aspect shown, the station 412 may be a load lock. In other aspects, the load lock module may be located between end entry / exit stations (similar to station 412), or an adjacent transfer chamber module (similar to module 18i) may be configured to operate as a load lock. As already described, the transfer chamber modules 18B, 18i may have one or more corresponding transfer devices 26B, 26i located in the transfer chamber modules 18B, 18i and including one or more aspects of the disclosed embodiment described herein.The transfer devices 26B and 26i of the respective transfer chamber modules 18B and 18i may cooperate to provide a workpiece transfer system 420 linearly distributed within the transfer chamber. In this aspect, the transfer device 26B may have a general SCARA (Selective Compliance Assembly Robot Arm) arm (horizontal articulated robot arm) configuration (however, in other aspects, the transfer arm may have any other desired arrangement such as a frog leg type configuration, a telescopic type configuration, a symmetric type configuration, etc.). In the aspect of the disclosed embodiment shown in FIG. 1D, as will be described in more detail below, the arm of the transfer device 26B may be arranged to provide a so-called fast swap arrangement that enables rapid wafer exchange from the pick / place location. The transfer arm 26B may have suitable drive units as described below to provide any appropriate degrees of freedom to each arm (e.g., Z-axis movement and independent rotation around the shoulder and elbow joints). As seen in FIG. 1D, in this aspect, the modules 56A, 56, 30i may be positioned intervening between the transfer chamber modules 18B and 18i and may define suitable processing modules, one or more load locks, one or more buffer stations, one or more measurement stations, or any other desired one or more stations. For example, intermediate modules such as the load locks 56A, 56, and the workpiece station 30i may each have stationary workpiece supports / shelves 56S, 56S1, 56S2, 30S1, 30S2 that cooperate with the transfer arm to enable workpiece transfer over the entire length of the transfer chamber along the linear axis X of the transfer chamber. As an example, one or more workpieces may be loaded into the transfer chamber 416 by the interface section 12. One or more workpieces may be positioned on one or more supports of the load lock module 56A using the transfer arm 15 of the interface section.Within load lock module 56A, one or more workpieces may be moved between load lock module 56A and load lock module 56 by transfer arm 26B within module 18B, and in a similar continuous manner, between load lock 56 and workpiece station 30i, and between station 30i and station 412, using arm 26i (within module 18i) within module 18i. To move one or more workpieces in the opposite direction, this process may be reversed, either in whole or in part. Thus, in one aspect, a workpiece may be moved in any direction along axis X and to any position along the transfer chamber, and may be loaded or unloaded to or from a desired module (processing module or another module) that communicates with the transfer chamber. In another aspect, an intermediate transfer chamber module having a stationary workpiece support or shelf is not provided between transfer chamber modules 18B and 18i. In such an aspect, the transfer arms of adjacent transfer chamber modules may transfer a workpiece directly from the end effector of one transfer arm to the end effector of another transfer arm to move the workpiece through the transfer chamber. A processing station module may operate on a substrate to form an electrical circuit or other desired structure on the substrate through various deposition, etching, or other types of processing. The processing station module is connected to the transfer chamber module to allow the substrate to pass from the transfer chamber to the processing station and vice versa. A suitable example of a processing tool having general features similar to the processing apparatus shown in FIG. 1D is described in U.S. Patent No. 8,398,355, which is already incorporated herein by reference.

[0018] FIG. 1E shows a substrate transfer device 100 according to an aspect of the disclosed embodiment. The aspects of the disclosed embodiments described herein are applicable to robots in a vacuum (e.g., a high vacuum that can be 10 -5 Torr or less, or any other suitable vacuum) and / or air, where the moving parts of the rotor and position feedback are isolated from their stationary electrical counterparts (e.g., the read head and stator). In general, the aspects of the disclosed embodiments include one or more switched reluctance motors for operating any suitable robotic arm. The moving part of the robot drive unit may be located within a sealed or isolated environment, which may be a controlled environment such as a vacuum environment or an atmospheric pressure environment. A non-magnetic separation or isolation wall made of any suitable material (described in more detail below) may be disposed between the moving part of the drive unit (e.g., the moving parts of the rotor and feedback) and the stationary part of the drive unit (e.g., the stator and the read head of the position sensor). However, unlike conventional isolation walls, the isolation walls described below can provide a minimized air gap between the stator and the rotor that is not substantially limited by the thickness of the isolation wall or is substantially independent of the thickness of the isolation wall.

[0019] As can be understood, the electrical components and / or permanent magnets may not be located within the isolated environment. The elements of the drive unit located within the isolated environment may include one or more ferromagnetic rotors with salient poles (not magnets), one or more ferromagnetic position feedback scales or tracks (not magnets), and one or more drive shafts with support bearings or, in another aspect where a self-bearing motor is provided, without support bearings. The rotor, position feedback scale or track, and drive shaft may be rigidly attached to each other and may be supported within the isolated environment in any suitable manner, such as using bearings or substantially without contact (e.g., a self-bearing motor). One or more drive shafts of the drive unit assembly may be connected in any suitable manner to respective joints of the robotic arm to provide direct drive capabilities of the robotic arm.

[0020] The stator and the reading head of the position sensor may be located outside the isolated environment. The reading head may be any suitable type of sensor, such as, for example, a magnetic transducer. In one aspect, the reading head can provide a magnetic field source and can provide sensing of the magnetic flux flowing between the reading head and a ferromagnetic scale or track disposed within the isolated environment. In one aspect, the position feedback reading head and track described herein may include a variable reluctance circuit substantially similar to that described in U.S. Patent No. 7,834,618, issued on November 16, 2010, entitled "Position Sensor System", the entire disclosure of which is incorporated herein by reference. In another aspect, the position feedback device may be any suitable type of position feedback device, such as optical, capacitive, inductive, etc., or other types of position encoding devices.

[0021] One or more stators of the drive assembly may provide a magnetic field by exciting each of its phases in an appropriate order and with phase currents, the magnitude of the phase currents being determined by any suitable control device, such as a control device 190 that may be similar to the control device 11091 or incorporated within the control device 11091, to produce a desired amount of torque. As can be appreciated, a reluctance motor may exhibit non-linearity and torque ripple, such as in the case of a three-phase configuration. The control device 190 may be configured to account for non-linearity and torque ripple during operation of the robot drive unit described herein. Referring to FIG. 1F, the control structure of the control device 190 may include, for example, an operation control module 190A, a rectification algorithm module 190B, and a current control module 190C arranged in a series manner. In another aspect, the control device 190 may include any suitable calculation / control modules arranged in any suitable manner. The operation control module 190A determines the commanded torque T for the robot motor from or based on the commanded position θ of the robot motor and the actual position θ of the robot motor obtained from one or more of the encoder 177 (which may include a reading head and tracks described herein). cmdi and the actual position θ of the robot motor obtained from one or more of the encoder 177 (which may include a reading head and tracks described herein). i From or based on those positions, the commanded torque T for the robot motor may be determined. cmdi (where i = 1, 2,..., M and M is the total number of operating axes of the robot drive unit).

[0022] The rectification algorithm module 190B calculates the commanded phase current i for each motor from or based on the commanded torque T for each motor of the robot motor. For purposes of illustration only, a single motor 177M is shown in FIG. 1F, but in another aspect, any suitable number of motors may be used. The rectification algorithm module 190B calculates the commanded phase current i from or based on the reciprocal of the torque-phase-position relationship of Equation 1 for the commanded torque T. cmdi From or based on the commanded torque T. cmdi Based on this, the commanded phase current i for each motor may be calculated. cmdj (where j = 1, 2,..., N and N is the total number of phases of each motor). For purposes of illustration only, a single motor 177M is shown in FIG. 1F, but in another aspect, any suitable number of motors may be used. The rectification algorithm module 190B calculates the commanded phase current i from or based on the reciprocal of the torque-phase-position relationship of Equation 1 for the commanded torque T. cmdiand the actual position θ of the motor i as a function of, the commanded phase current i cmdj may be configured to determine. As can be understood, in one aspect, the commanded phase current cmdj a look-up table may be used to determine. [Number]

[0023] The current control device 190C may be configured to calculate the voltage for the motor phase u cmdj to generate a phase current i that strictly adheres to the commanded value of i j . To improve the performance of the current control section of the control device 190, a model method or any other suitable method may be used. j

[0024] ​Referring again to FIG. 1E, the substrate transfer device 100 may include, for example, a direct drive motor configuration that includes reluctance-based actuation (e.g., variable / switch reluctance motor) and reluctance-based sensing (e.g., position feedback). In another aspect, any suitable actuator and sensor may be used. The switched reluctance motor may substantially remove or reduce the presence of magnets and adhesive joints from the rotor of the robot drive unit. The reluctance-based position feedback, which may be substantially similar to that described in U.S. Patent No. 7,834,618 (the disclosure of which is hereby incorporated by reference in its entirety), may provide for sensing the position of the rotor in a non-intrusive manner, such as through the isolation wall of the motor, so that the sensor read head is not exposed to a vacuum and / or an active and corrosive environment, as will be described in more detail below. As described above, the substrate transfer device 100 and other transfer devices described herein may include a control device 190 configured to reduce the torque ripple of the switched reluctance motor, for example, to achieve smooth (e.g., jerk-free) operation for direct drive substrate transfer. The motor and position sensing configurations described herein may be used together as described herein and / or independently in combination with any other suitable actuation or position sensing technology.

[0025] The reluctance-based actuation and position sensing configurations described herein may be used in the architecture of any suitable robotic actuator having one or more axes of motion (e.g., degrees of freedom). One-axis and two-axis robotic actuator configurations (e.g., planar / pancake actuator configurations, stacked actuator configurations, bearingless actuator configurations, and integrated actuator / pump configurations, including but not limited to these) suitable for driving single or dual end effector robotic arms are described herein for illustrative purposes, but it should be understood that the aspects of the invention described herein are applicable to any suitable substrate transfer actuator having any desired number of axes of motion for driving any suitable number of robotic arms.

[0026] In one aspect, the substrate transfer apparatus 100 is shown having a low-profile planar, or "pancake" type robot drive configuration, in substantially the same manner as described in U.S. Patent No. 8,008,884, issued August 30, 2011, entitled "Substrate Processing Apparatus with Motors Integral to Chamber Walls", and U.S. Patent No. 8,283,813, issued October 9, 2012, entitled "Robot Drive with Magnetic Spindle Bearings", the entire disclosures of which are incorporated herein by reference. For example, due to the relatively large rotor diameter and relatively high torque performance, the pancake type drive structure may provide a direct drive alternative to harmonic drive® robots for high / heavy load applications. In other aspects, any suitable harmonic drive® may be coupled to the output of the motors described herein to drive one or more robot arms. The pancake type drive configuration also enables a hollow central drive that supports partial or complete integration of a vacuum pump configuration within the robot drive, such as within a small vacuum chamber that may house the inlet of a vacuum pump and / or have limited space around the robot drive, or within any other suitable chamber in which the robot drive is at least partially disposed internally.

[0027] The substrate transfer apparatus 100 may include a reluctance drive unit 100D having one or more stators and corresponding rotors (including, in this aspect, outer rotor 101 and inner rotor 102). The rotors 101, 102 may be actuated by their respective stators through a housing or partition wall 103 (described in more detail below) based on the principles of the reluctance motors described herein.

[0028] Referring to FIGS. 1G and 1H, which show a top view and a side cross-sectional view of the rotor 166 according to an aspect of the disclosed embodiments, the rotor 166 may be a laminated rotor. The rotor 166 may be substantially similar to the rotors described herein and may include a set of laminates of alternating layers 167 of ferromagnetic material and non-conductive layers 168, which in this example are stacked along the axis of rotation of the rotor (e.g., such that the laminates extend radially from the axis of rotation) to form a radially laminated rotor through which magnetic flux flows along the laminates. In another aspect, the laminates may be arranged in any suitable manner, such as being arranged along the axis of rotation as shown in FIG. 1K, which shows a top view of an axially laminated rotor, to form an axially laminated rotor. Here, in a substantially similar manner to that described hereinafter for the radially laminated rotor, the axially laminated rotor may also have alternating ferromagnetic layers 167' and non-conductive layers 168'. The axially arranged laminates may be aligned with and attached to the hub or drive shaft 169' in any suitable manner, such as using any suitable alignment mechanism 171 and any suitable fastener 172, in a substantially similar manner to that described hereinafter for the radially laminated rotor 166. Thus, the aspects of the disclosed embodiments described herein may be applicable to axial flux machines and / or radial flux machines. Each layer of material may have any suitable thickness, for example, from about 0.014 inches to about 0.025 inches or from about 0.35 mm to about 0.65 mm. In another aspect, the thickness of each laminate may be greater or less than the approximate range of thicknesses described above. As can be understood, the thinner each layer of material (through which the magnetic field flows), the less the effect of eddy currents on the switched reluctance motor. The ferromagnetic material may be a stamped (or formed in any suitable manner) sheet of any suitable material, such as 300 series or 400 series stainless steel.The non-conductive layer may be formed from any suitable material, such as an electrically insulating vacuum-compatible epoxy and / or a vacuum-compatible thin sheet, or other materials including but not limited to glass, ceramic, Teflon®, and polyester film tape. The stacked laminates 167, 168 may be aligned for assembly in any suitable manner, such as using an alignment mechanism 171 attached to, for example, a hub 169. In one aspect, the alignment mechanism 171 may include a set of pins, and the hub 169 may be part of a drive shaft, such as a drive shaft described herein, or form a drive shaft so that the rotor is attached to the drive shaft substantially directly. The stacked laminates 167, 168 may be clamped or held together in any suitable manner, such as using a clamping mechanism 172. In one aspect, the clamping mechanism may be a nut configured to be mounted on the alignment mechanism 171. In another aspect, the alignment mechanism may be removed and replaced by a clamping mechanism, such as a bolt passing through the laminate to connect to the hub or drive shaft to which the rotor is attached. In yet another aspect, the stacked laminates may be aligned using external fixtures and / or bonded together using a vacuum-compatible adhesive or other suitable adhesive. Referring also to FIGS. 1I and 1J, in another aspect, the stacked laminates 167, 168 may be completely embedded by an outer shell 174 of any suitable material, such as a vacuum-compatible adhesive, in such a way that the laminate is isolated or sealed from, for example, a vacuum environment, a corrosive environment, or other environments in which a robotic arm driven by a robotic drive unit operates (e.g., all sides may be completely surrounded and sealed). If the rotor is an insulating rotor, the ferromagnetic layer 167 may be composed of any suitable material, such as silicon steel separated by, for example, any suitable electrically insulating material (which may be the same as or different from the material embedding the stacked laminates 167, 168).

[0029] In another aspect, as can be appreciated, the switching frequency in the application of the direct drive can be relatively low, which may enable the use of a solid stator, for example, without substantially accompanying excessive loss levels due to eddy currents. As shown in FIG. 1L, the stator 206' of the direct drive motor may be laminated using a laminate (e.g., a laminate of alternately arranged ferromagnetic layers 167" and non-conductive layers 168") that is generally configured and formed in the same manner as the above-described rotor laminate. The laminate may be positioned with respect to the forces of the torque axis as described for optimal power and minimization of losses, for example, due to eddy currents. As can be appreciated, the portion of the laminated stator that is external to the sealed boundary or frame (e.g., the wall 103 shown in FIG. 1E that includes a sealed environment) may be exposed to the external atmosphere without being sealed. Thus, according to one aspect, the motor drive unit may include a laminated rotor or a solid rotor that is driven by switched reluctance via a solid or (wholly or partially) laminated stator.

[0030] The drive unit 100D may have any suitable robotic arm 104 configured to transport, for example, a semiconductor wafer, a flat panel for a flat panel display, a solar panel, a reticle, or any other suitable load. In this aspect, the robotic arm 104 is illustrated as a symmetric robotic arm (e.g., having opposing end effectors connected in extension and retraction), with one of the upper arms 104U1, 104U1' attached to the outer rotor 101 and the other upper arms 104U2, 104U2" attached to the inner rotor 102. In another aspect, the robotic arm may be a SCARA (Selective Compliance Assembly Robot Arm) (horizontal articulated robotic arm), a telescoping arm, or any other suitable arm. The operation of the arms may be independent of each other (e.g., the extension / retraction of each arm is independent of the other arms), may be operated through a lost motion switch (described below), or may be operably coupled in any suitable manner such that the arms share at least one common drive axis. As an example, the radial extension movement of either of the end effectors 104E1, 104E2 of the symmetric arm may be performed by rotating the outer rotor 101 and the inner rotor 102 in opposite directions at substantially the same speed, substantially simultaneously. The integral rotation of the arm 104 may be performed by rotating the outer rotor 101 and the inner rotor 102 in the same direction at substantially the same speed.

[0031] As can be understood, the partition wall 103 separates, for example, the atmosphere in which the arm 104 operates (e.g., a vacuum or other suitable controlled atmosphere) from the ambient atmosphere (e.g., an atmospheric environment that is usually substantially at atmospheric pressure). Note that the outer and inner rotors 101, 102 and the robot arm 104 are located, for example, within a vacuum environment, while the operating coils (e.g., the stator) of the motor and the position sensors are located in the atmospheric environment. The reluctance motor configuration of the drive unit 100D and / or the reluctance-based feedback position sensor may provide a partition wall 103 that does not have an opening, a viewport, or a feed-through configuration. The partition wall 103, which will be described in more detail below, may be composed of a non-ferromagnetic material or other suitable material that allows the magnetic fields associated with the operating and position sensing configurations to pass through the partition wall 103.

[0032] Figures 2A and 2B schematically show cross-sectional views of the exemplary robot drive unit of FIG. 1E. In one aspect, the inner and outer rotors 101, 102 may be suspended from the motor housing in any suitable manner, such as by bearings 205. In another aspect, the drive unit 100D may be a self-bearing drive unit in which the rotors 101, 102 are suspended in any suitable manner without substantial contact. The propulsion coil or stator 206 and the position sensing read heads 207, 208 may be located in different angular sectors (e.g., the ambient environment) on the opposite side of the partition wall 103 from the respective rotors 101, 102. The read head 207 may interact with any suitable absolute scale or track 209 to provide a rough measurement of the absolute position of the respective rotors 101, 102. The read head 208 may interact with an incremental scale or track 210 to determine the high-resolution position of the respective rotors 101, 102. The tracks 209, 210 may be made of ferromagnetic material or other suitable material such that the tracks 209, 210 close or affect a magnetic circuit that includes the respective read heads 207, 208. Combining the measurements obtained from the tracks 209, 210 (absolute and incremental) provides a complete high-resolution absolute position for the rotors 101, 102.

[0033] FIG. 3 is a schematic cross-sectional view of the robot drive unit 100D of FIG. 1E for illustrating the structure of the drive unit. As can be understood, the stator 206, the rotors 101, 102, the reading heads 207, 208 of the position sensors, and the tracks 209, 210 may be arranged as described above with respect to FIGS. 2A and 2B. In another aspect, the stator, the rotors, and the position sensors may have any suitable arrangement. As seen in FIG. 3, the rotor 101 includes a first shaft, post, or extension 301 to which one of the upper arms 104U1 (FIG. 1E) is attached and supported. The rotor 102 includes a second shaft, post, or extension 302 to which another upper arm 104U2 (FIG. 1E) is attached and supported. As seen in FIG. 3A, the arrangement of the two shafts 301, 302 and the drive motor may provide a hollow central portion in the drive unit 100D, for example, to allow access to a vacuum source 370 (or other suitable peripheral processing device for the operation of the transfer chamber in which the arm 104 operates) that should be arranged at the center of the drive unit and / or to support a partial or complete integration of the vacuum pump arrangement into the robot drive unit. The two shafts 301, 302 may support the arm 104 for rotation of the arm as a single unit and / or for extension / retraction of the end effectors 104E1, 104E2 as described above.

[0034] FIG. 4 is a schematic cross-sectional view of a robot drive unit 100D' that is substantially similar to the drive unit 100D described above. However, in this aspect, the drive unit can include any suitable number of drive shafts corresponding to the number of motors included in the robot drive unit, including a substantially concentrated (e.g., substantially concentrically located within a stator / rotor configuration) coaxial drive shaft assembly 400. In this aspect, the coaxial drive shaft assembly 400 includes an inner drive shaft 402 and an outer drive shaft 401 that are supported in any suitable manner, such as by bearings. In another aspect, as described above, the drive unit may be a self-bearing drive unit such that the drive shaft assembly 400 can be supported without substantial contact (e.g., via connection to a rotor). In this aspect, the outer drive shaft 401 may be connected to the outer rotor 101 in any suitable manner, such as by a drive member 401D, while the inner drive shaft 402 may be connected to the inner rotor 102 in any suitable manner, such as by a drive member 402D. As can be understood, this drive unit arrangement can facilitate connection to a symmetric robot arm assembly, a scalar robot arm assembly, a telescoping robot arm assembly, a robot arm assembly having a lost motion switch, or any other suitable robot arm assembly that includes one or more robot arms and utilizes a coaxial drive shaft configuration for the operation of one or more of the robot arms.

[0035] FIG. 5 is a schematic cross-sectional view of a robot drive unit 500 that may be substantially the same as the drive unit 100D. In this embodiment, the pair of stator 206 / rotors 101, 102 may be stacked vertically. In this embodiment, as seen in FIG. 5, rotor 101 includes a first shaft 301' to which one of the upper arms 104U1 (FIG. 1E) is attached and supported. Rotor 102 includes a second shaft 302' to which the other upper arm 104U2 (FIG. 1E) is attached and supported. Also, as seen in FIG. 5A, the arrangement of the two shafts 301', 302' and the drive motor may provide access to a vacuum source 370' (or other suitable peripheral processing device for the operation of the transfer chamber in which the arm 104 operates) and / or support partial or complete integration of a vacuum pump arrangement within the robot drive unit in a manner substantially similar to that described above by providing a hollow central portion of the drive unit.

[0036] FIG. 6 is a schematic cross-sectional view of a robot drive unit 600 that may be substantially the same as the drive unit 100D'. In this embodiment, the pair of stator 206 / rotors 101, 102 may be stacked vertically. In this embodiment, the coaxial drive shaft assembly 400' includes an inner drive shaft 402' and an outer drive shaft 401' supported in any suitable manner as described above. The outer drive shaft 401' may be connected to the outer rotor 101 in any suitable manner, such as by a drive member 401D', while the inner drive shaft 402' may be connected to the inner rotor 102 in any suitable manner, such as by a drive member 402D'.

[0037] Figures 7 to 15 show additional motor configurations according to aspects of the disclosed embodiments. Referring to FIG. 7, a single-axis drive unit 1590 is shown. In this aspect, a part of the transfer chamber 1500 is shown such that the partition wall 103 or other parts of the drive unit housing are connected to the housing of the transfer chamber 1500, and this interface is the isolation interface 1520. The isolation interface may be any suitable sealing interface for isolating the environment, such as an O-ring, for example. Here, a single drive shaft 1509 is connected to the rotor 1501. The stator 1506 is disposed outside the rotor 1501 such that the stator 1506 substantially surrounds the rotor 1501. FIG. 8 also shows a single-axis drive unit 1690 that is substantially the same as the drive unit 1590 shown in FIG. 7. However, the drive unit 1690 is arranged such that the stator 1606 is placed inside the rotor 1601 so that the rotor 1601 substantially surrounds the stator 1606.

[0038] Note that additional drive shafts (e.g., degrees of freedom) may be added by stacking drive units either vertically and / or radially to transmit torque to one or more robotic arms and utilizing a coaxial drive shaft arrangement. Here, the rotor, stator, position feedback reading head, and track may be substantially the same for each axis of motion. For example, referring to FIG. 9, a pancake-type drive unit 1790 that is substantially the same as the drive unit 100D' described above is shown having coaxial drive shafts 1509A, 1509B. As seen in FIG. 9, the drive unit 1790 is arranged such that each stator 1506 is placed outside its respective rotor 1501, 1502 such that the stator 1506 substantially surrounds its respective rotor 1501, 1502 and one motor substantially surrounds another (e.g., one motor is nested inside another). FIG. 10 shows a drive unit 1890 that is substantially the same as the drive unit 1790, but in this aspect, the stator 1506 is placed inside its respective rotors 1501, 1502 such that the rotors 1501, 1502 substantially surround their respective stators 1506.

[0039] As can be understood, a Z-axis drive unit may be added to any of the robot drive units described herein. For example, FIG. 11 shows any suitable Z-axis drive unit 1900 connected to the drive unit 1790 to move the drive unit 1790 in the direction of arrow 1910 (e.g., in a direction substantially parallel to the rotation axis of the drive rotor). Any suitable guide such as a rail 1930 may be provided to guide the Z-axis movement of the drive unit 1790. The Z-axis drive unit may include any suitable linear drive mechanism 1900D, such as a ball screw drive mechanism, a linear magnetic drive unit, a scissor-type lift, or any other suitable mechanism capable of moving the drive unit 1790 along a linear path. To seal the interface between the housing of the drive unit and the transfer chamber 1500, any suitable flexible seal 1940, such as a bellows, may be provided at the interface between the stator housing (or partition wall 103) and the drive unit housing. FIG. 12 shows a two-axis drive unit 2000 substantially similar to the above-described one, with the drive motors stacked vertically. FIG. 13 shows a two-axis drive unit 2000 having a Z-axis drive unit 1900. Here too, although single-axis and two-axis drive units are described herein, it should be noted that in another aspect, the drive unit may have any suitable number of drive axes. As seen in FIGS. 11 and 12, the vertically stacked motors are arranged such that the stator 1506 is placed outside their respective rotors 1501, 1502. FIG. 14 shows a drive unit 2100 having a vertically stacked motor arrangement, where the stator 1506 is placed inside its respective rotors 1501, 1502 such that the rotors 1501, 1502 substantially surround their respective stators 1506.

[0040] In another aspect, the position feedback read head and the track may be configured as a module in which the read head is insertable into and removable from the drive unit housing or the isolation wall 103. For example, referring to FIG. 15, a drive unit 2000’ is shown. The drive unit 2000’ may be substantially similar to the drive unit 2000 described above. However, the track 209’ may be arranged such that the read head 207’ can interact with the track from above and below rather than in the radial direction (as shown in FIG. 12 for example). The read head 207’ may be in sealed connection with and removable from the isolation wall 103 or the housing of the drive unit 2000’, and may be arranged in a removable read head insertion part or module 2110. Any suitable sealing part may be provided at the interface between the module 2110 and the isolation wall 103 or the drive unit housing. In another aspect, the module 2110 or the sensor / track isolation wall may be machined within the drive unit housing. This drive unit housing can be stacked with another drive unit housing, and a static sealing part such as an O-ring is positioned between the drive unit housings. In one aspect, the track 209’ may be a combined track including both incremental tracks and absolute tracks. The read head 207’ may be configured such that both the absolute track and the incremental track are read by the read head 207’. In another aspect, a plurality of tracks may be provided along one or more modules 2110 having one or more read heads for reading each of the incremental tracks and the absolute tracks. In yet another aspect, the removable read head module and the position feedback track may be configured such that the read head of the module is arranged radially with respect to the track (as shown in FIG. 12).

[0041] As described above, in one aspect, the arrangement of the robot drive unit of the switched reluctance motor described herein may be part of the self-bearing drive unit or may include the self-bearing drive unit. In that self-bearing drive unit, active and passive magnetic forces, as described in U.S. Patent Application Publication No. 11 / 769,651, filed Jun. 27, 2007, entitled "Reduced-Complexity Self-Bearing Brushless DC Motor," the entire disclosure of which is hereby incorporated by reference, suspend the rotating portion of the robot drive unit (and robot arm) in place of mechanical bearings. In one aspect, the self-bearing drive unit may include the switched reluctance motor and sensing configuration described herein in combination with a dedicated centering / suspension winding. In another aspect, the windings of the switched reluctance motor may be divided into separately / independently controlled coil sections to form an integral self-bearing motor as shown in FIGS. 16A and 16B.

[0042] In one aspect, as shown in FIG. 16A, each motor of the robot drive unit 700 may include three winding sets 720 - 722 that extend across three sectors of the rotor 710. In another aspect, any suitable number of winding sets may be provided to drive the rotor 710. Each of the winding sets 720 - 722 may be driven by any suitable control device 190 in any suitable manner, as described in U.S. Patent Application Publication No. 11 / 769,651, which is hereby incorporated by reference. The stator winding sets 720 - 722 are shown as being approximately equally distributed (e.g., offset from each other by approximately 120 degrees), but it should be understood that other offsets may also be utilized. In another aspect, the winding sets 720 - 722 may be arranged in a configuration that is generally symmetric about the desired axis but unevenly distributed around the periphery of the stator.

[0043] In another aspect, as shown in FIG. 16B, the motors 701 of the robot drive unit 701 may each include a stator having two winding sets A and B having two winding subsets 730, 733 and 731, 732 respectively (e.g., a four-segment stator winding arrangement). The two winding subsets in each winding set are electrically connected and are shifted relative to each other by approximately 90 electrical degrees. As a result, when one of the pair of two winding sets generates a pure tangential force, the other winding set of the pair generates a pure radial force, and vice versa. In the exemplary embodiment shown, the respective segments of each winding set may be geometrically arranged at an angle of approximately 90°. In another aspect, the geometric angle offset and the electrical angle offset between the winding segments of each winding set may be different from each other. Each of winding sets A and B may be driven in any suitable manner by any suitable control device 190 as described in U.S. Patent Application Publication No. 11 / 769,651, which is hereby incorporated by reference.

[0044] As can be appreciated, in one aspect, the lift force may be provided to suspend the rotating parts of the drive units 700, 701 (e.g., the rotors 710, the robot arm, the position feedback track, etc.) in the vertical direction and / or to stabilize additional degrees of freedom such as, for example, the pitch angle and the roll angle of the drive shaft of the drive unit (i.e., the robot arm attached to the drive shaft). In one aspect, it may be provided by a dedicated winding, and in another aspect, it may be provided passively through a magnetic circuit using, for example, permanent magnets positioned in the air portion of the drive system.

[0045] As described above, any suitable number and type of robotic arms 104 (FIG. 1E) may be attached to the drive unit motor arrangement described herein. In addition to the symmetric arms 104 (FIG. 1E), examples of other arm configurations that may be used in a pancake motor arrangement or a stacked motor arrangement include, but are not limited to, the arm configuration described in U.S. Patent Application Publication No. 12 / 117,415, filed May 8, 2008, entitled "Substrate Transport Apparatus with Multiple Movable Arms Utilizing a Mechanical Switch Mechanism," the entire disclosure of which is incorporated herein by reference. For example, the arm may be obtained from a conventional scalar design, including an upper arm, a band-driven forearm, and an end effector constrained by the band, by removing the upper arm. For example, in the manner shown in FIGS. 17A-14B, the structural role of the upper arm may be directly assumed by one or more rotors.

[0046] Referring to FIGS. 17A and 17B, a single end effector arm driven by a linkage mechanism is shown. Referring to the kinematic diagram of FIG. 17A, in this aspect, arm 1000 can be attached to a pair of coaxial rotors that are independently actuated, such as rotors 101, 102 (see also FIG. 1E). Arm 1000 may include a first linkage mechanism 1003, an end effector 1004, and a second linkage mechanism 1005. The first linkage mechanism 1003 may be connected to rotor 101 through a rotary joint 1006. The end effector 1004 may be connected to the first linkage mechanism 1003 through a rotary joint 1007 and may be restricted to face radially by a band configuration 1008. The second linkage mechanism 1005 may be connected to rotor 102 and end effector 1004 through rotary joints 1009 and 1010, respectively. Arm 1000 may be rotated by moving rotors 101 and 102 uniformly in the same direction. The radial extension of the arm may be controlled by moving rotors 101 and 102 simultaneously in opposite directions. An exemplary radial extension movement of arm 1000 can be implemented in a manner substantially similar to that described in, for example, U.S. Patent Application Publication No. 12 / 117,415 (already incorporated by reference) and is shown in a stepwise fashion in FIG. 17B.

[0047] Next, referring to FIGS. 18A and 18B, a single end effector arm 1100 driven by a linear band is shown in accordance with aspects of the disclosed embodiments. Similar to arm 1000, arm 1100 is attached to a pair of coaxially rotors 101 and 102 (see also FIG. 1E) that are independently actuated. In this aspect, arm 1100 includes a linkage mechanism 1103, an end effector 1104, and a linear band drive 1105. Linkage mechanism 1103 may be connected to rotor 101 through a rotational joint 1106 and coupled to rotor 102 through band drive 1105. End effector 1104 may be coupled to the first linkage mechanism 1103 through a rotational joint 1107 and may be restricted to face radially by a band configuration 1108. In this aspect, arm 1100 may be rotated by moving rotors 101 and 102 in the same direction by equal angles. The radial extension of the arm may be controlled by moving rotors 101 and 102 simultaneously in opposite directions (e.g., by equal amounts if band drive 1105 includes a 1:1 pulley ratio, although any suitable ratio may be used). An exemplary radial extension movement of arm 1100 can be implemented in a manner substantially similar to that described in, for example, U.S. Patent Application Publication No. 12 / 117,415, which is hereby incorporated by reference, and is shown in FIG. 18B in a stepwise fashion.

[0048] Referring to FIGS. 19A and 19B, a single end effector arm 1200 driven by a crossed band is shown in accordance with aspects of the disclosed embodiments. As shown in FIG. 19A, the arm 1200 may be attached to a pair of coaxially rotors 101 and 102 (see also FIG. 1E) that are independently actuated. In this aspect, the arm 1200 includes a linkage mechanism 1203, an end effector 1204, and a crossed band drive 1205. The linkage mechanism 1203 may be attached to the rotor 101 through a rotary joint 1206 and may be coupled to the rotor 102 through the crossed band drive 1205. The end effector 1204 may be coupled to the first linkage mechanism 1203 through a rotary joint 1207 and may be radially oriented by a band configuration 1208. In this aspect, the arm 1200 may be rotated by moving the rotors 101 and 102 in the same direction by equal angles. The radial extension of the arm may be controlled by moving the rotors 101 and 102 simultaneously in the same direction by different amounts. An exemplary radial extension movement of the arm 1200 can be implemented in a manner substantially similar to that described in, for example, U.S. Patent Application Publication No. 12 / 117,415, which is hereby incorporated by reference, and is shown in a stepwise fashion in FIG. 19B.

[0049] In aspects of the disclosed embodiments, referring to FIGS. 19C and 19D, a dual end effector arm assembly 1300 is shown. The arm assembly 1300 may be attached to a pair of coaxially rotatable rotors 101 and 102 (see also FIG. 1E) that are independently actuated. The left arm may include a first link mechanism 1303L, an end effector 1304L, and a second link mechanism 1305L. The first link mechanism 1303L may be connected to the rotor 102 through a rotary joint 1306L. The end effector 1304L may be connected to the first link mechanism 1303L through a rotary joint 1307L and may be restricted to face radially by a band configuration 1308L. The second link mechanism 1305L is connected to the rotor 101 and the first link mechanism 1303L through rotary joints 1309L and 1310L, respectively. Similarly, the right arm includes a first link mechanism 1303R, an end effector 1304R, and a second link mechanism 1305R. The first link mechanism 1303R may be connected to the rotor 102 through a rotary joint 1306R. The end effector 1304R may be connected to the first link mechanism 1303R through a rotary joint 1307R and may be restricted to face radially by a band configuration 1308R. The second link mechanism 1305R may be connected to the rotor 101 and the first link mechanism 1303R through rotary joints 1309R and 1310R, respectively. When one of the arms extends radially, the other arm rotates within a specific swing radius to near its folded configuration such that the link mechanism forms a lost motion mechanism. An exemplary radial extension movement of the arm assembly 1300 can be implemented in a manner substantially similar to that described in, for example, U.S. Patent Application Publication No. 12 / 117,415, which is already incorporated by reference, and is shown in a stepwise fashion in FIG. 19D.

[0050] In another aspect of the disclosed embodiments, the arm assembly 1400 shown in FIGS. 19E and 19F includes substantially the same types and numbers of components as the arm 1300. However, the arm components are arranged in different geometric configurations, resulting in a lost motion mechanism with substantially different kinematic characteristics. As shown in FIG. 19E, the left arm includes a first link mechanism 1403L, an end effector 1404L, and a second link mechanism 1405L. The first link mechanism 3L may be connected to the rotor 101 through a rotary joint 1406L. The end effector 1404L may be connected to the first link mechanism 1403L through a rotary joint 1407L and may be restricted to face radially by a band configuration 1408L. The second link mechanism 1405L may be connected to the rotor 102 and the first link mechanism 1403L through rotary joints 1409L and 1410L, respectively. Similarly, the right arm includes a first link mechanism 1403R, an end effector 1404R, and a second link mechanism 1405R. The first link mechanism 1403R may be connected to the rotor 101 through a rotary joint 1406R. The end effector 1404R may be connected to the first link mechanism 1403R through a rotary joint 1407R and may be restricted to face radially by a band configuration 1408R. The second link mechanism 1405R may be connected to the rotor 102 and the first link mechanism 1403R through rotary joints 1409R and 1410R, respectively. When one of the arms extends radially, the other arm rotates within a specific swing radius up to near its folded configuration. An exemplary radial extension movement of the arm 1400 can be implemented in a substantially similar manner as described in, for example, U.S. Patent Application Publication No. 12 / 117,415 (already incorporated by reference) and is shown in a step-by-step format in FIG. 19F.

[0051] Next, referring to FIG. 20A, a schematic view of a part of the transfer device drive unit 20200 is shown. The transfer drive unit can be used for any suitable air or vacuum robot transfer, such as the one described above. The drive unit may include a drive unit housing 20200H having at least one drive shaft 20201 with at least a part thereof disposed therein. Although one drive shaft is shown in FIG. 20A, in other embodiments, the drive unit may include any suitable number of drive shafts. The drive shaft 20201 may be mechanically or magnetically suspended within the housing 20200H in any suitable manner. In this embodiment, the drive shaft is suspended within the housing using any suitable bearing 20200B, but in other embodiments, the drive shaft may be magnetically suspended in a manner substantially similar to that described in U.S. Patent No. 8,283,813, issued on October 9, 2012, titled "Robot Drive with Magnetic Spindle Bearings", the entire disclosure of which is incorporated herein by reference (e.g., self-bearing drive). Each drive shaft of the drive unit 20200 may be driven by a respective motor 20206, each including a stator 20206S and a rotor 20206R. The exemplary embodiment shown in the figure has what may be referred to as a rotational drive structure, which is illustrated for the purpose of facilitating the description of the features of various aspects as shown and described herein. As can be understood, the features of the various aspects illustrated in connection with the rotational drive structure are equally applicable to a linear drive structure. Note that the drive motors described herein may be permanent magnet motors, variable reluctance motors (having at least one salient pole with a corresponding coil unit and at least one respective rotor having at least one salient pole of a permeable material), or any other suitable drive motor. One or more stators 20206S may be at least partially fixed within the housing, and one or more rotors 20206R may be fixed to their respective drive shafts 20201 in any suitable manner.In one aspect, by using a partition or a barrier, one or more stators 206S may be disposed in an "external" or "unsealed" environment that is sealed from the atmosphere in which one or more robot arms 20208 operate (in this specification, the environment in which one or more robot arms operate is referred to as a "sealed" environment and may be a vacuum or any other suitable environment), while one or more rotors 20206R are disposed in a sealed environment in a manner substantially similar to that described in a U.S. Provisional Patent entitled "SEALED ROBOT DRIVE", filed on November 13, 2013, having Attorney Docket No. 390P014939-US (-#1), the entire disclosure of which is incorporated herein by reference. The term non-ferromagnetic partition, sealing partition wall, or barrier (described in more detail below) as used herein refers to a wall made of any suitable non-ferromagnetic material and can be disposed between the moving parts of a robot drive and / or sensor and the corresponding stationary parts of the robot drive and / or sensor.

[0052] In one aspect, the housing 20200H of the drive unit 20200 has a substantially drum-shaped configuration (e.g., a drum structure) having an outer surface 20200HE and an inner surface 20200HI. In one aspect, the housing 20200H is a single integral structure, while in other aspects, the housing 20200H is an integral assembly having two or more hoop members fastened to each other in any suitable manner so as to form the drum structure of the housing 20200H. The inner surface 20200HI of the housing includes a stator interface surface 20200HS where the stator 20206S of the variable reluctance motor 20206 is located. The stator interface surface 20200HS (and thus, and the housing 20200H) is configured to provide rigidity and support for the stator 20206S. As can be understood, the stator interface surface 20200HS (and thus, and the housing 20200H) is a reference surface for positioning the stator 20206S (and, in one aspect, a partition wall 2403 supported by the stator so that the stator is located in an atmospheric environment separated from the vacuum environment where the rotor is located) so as to control the gap between the stator 20206S and the rotor 20206R. The housing 20200H also includes a rotor interface surface 20200HR that connects to and positions the rotor 20206R so that the rotor 20206R is positioned in a predetermined position relative to the stator 20206S (e.g., a bearing 20200B is positioned on the drive shaft 20101 / rotor 20206R at a predetermined position and the bearing 20200B connects to the rotor interface surface 20200HR). As can be understood, the stator interface surface 20200HS is a reference surface for the rotor interface surface 20200HR (and thus, and the rotor 20206R / drive shaft 20201) such that the rotor 20206R (and the drive shaft 20201 connected to the rotor 20206R) and the stator 20206S are positioned relative to a common reference formed by the housing 20200H and dependent on the common reference surface.In one aspect, the housing 20200H includes an opening or slot PCBS for a control board formed within the housing 20200H, within which is located a printed circuit board PCB (similar to the PCB 20310 described below) including one or more sensors 20203 (described below) that interact with a sensor track or encoder track 20202, and is separated from the sensor track 20202 (located within a vacuum environment) by a vacuum barrier in a manner similar to that described below. The opening PCBS for the control board includes a sensor interface surface 20200HT that positions the sensor 20203 at a predetermined position relative to a stator interface surface 20200HS (e.g., a common reference plane of the housing 20200H). As can be understood, the sensor track 20202 is connected to the rotor 20206R such that it is located at a predetermined position relative to a rotor interface surface 20200HR. In this way, the relative arrangement of the sensor interface surface 20200HT and the rotor interface surface 20200HR with respect to the stator interface surface 20200HS arranges and controls the gap between the sensor 20203 and the sensor track 20202 such that the stator 20206S, rotor 20206R, sensor 20203, and sensor track 20202 are positioned relative to and dependent on a common reference plane. In one aspect, the housing 20200H includes any suitable slot or opening MLS through which any suitable connector CON passes to supply power and control signals (and feedback signals from the drive unit 20200) to the drive unit 20200.

[0053] Figures 20G - 20J illustrate, for illustrative purposes only, a drive unit having a single drive shaft 20201. However, referring to Figure 20K, in other embodiments, it should be understood that the drive unit may include any suitable number of motors having any suitable number of corresponding drive shafts. For example, Figure 20K illustrates a drive unit 20200” having two motors 20206A, 20206B arranged in a stacked or in - line configuration. Here, each motor 20206A, 20206B includes its own housing 20200H (substantially similar to those described above), and the drive shaft 20201 of motor 20206B extends through an opening in the drive shaft 20201A of motor 20206A such that the housings are connected to each other in any suitable manner to form a multi - motor (e.g., multi - degree - of - freedom) drive unit 20200”.

[0054] Referring to FIG. 20B, a transport device drive unit 20200', which is substantially similar to the drive unit 20200, is shown having a coaxial drive shaft structure with two drive shafts 20201, 20210. In this embodiment, the drive shaft 20201 is driven by a motor 20206 (having a stator 20206S and a rotor 20206R), and the drive shaft 20210 is driven by a motor 20216 (having a stator 20216S and a rotor 20216R). Here, the motors are shown in a stacked structure (e.g., arranged in a row, stacked vertically, or arranged front to back). However, it should be understood that the motors 20206, 20216 may have any suitable configuration such as side-by-side or concentric configurations. Suitable examples of motor configurations are described in U.S. Patent No. 8,008,884, issued on August 30, 2011, entitled "Substrate Processing Apparatus with Motors Integral to Chamber Walls", and U.S. Patent No. 8,283,813, issued on October 9, 2012, entitled "Robot Drive with Magnetic Spindle Bearings", the entire disclosures of which are incorporated herein by reference.

[0055] Referring again to FIGS. 20A and 20B, and FIG. 20C, each drive shaft 20201 may also have a sensor track or encoder track 20202 attached to the drive shaft 20201 that includes a position measurement marker or a feature that interacts with a sensor 20203. Note that the sensors described herein are configured such that the reading head portion of the sensor 20203 (e.g., the portion of the sensor where the sensing member is attached) can be inserted into and removed from the drive housing or the partition wall 20204 (note that the partition wall 20204 may be a common partition wall that seals the drive stator from the sealed environment). The sensing element or sensing member 20203H of the sensor 20203 reads one or more scales 20202S (described below) or is affected by the scale 20202S in any suitable manner to supply a position signal to any suitable control device, such as an operation control device 190 (which may be substantially similar to the control device 11091 described above). The sensor 20203 may be at least partially fixed within the housing 20200H. In some embodiments, at least a portion of the sensor 20203 may be located in the external environment such that the sensor electronics and / or magnets are located in the external environment while the sensor track is located in the sealed environment and may be sealed or isolated from the sealed environment using a partition wall 20204 described in more detail below. The sealed environment is difficult to directly monitor due to harsh environmental conditions, such as a vacuum environment or an environment with extreme temperatures. Aspects of the disclosed embodiments described herein provide non-invasive position measurement of a moving object (e.g., a motor rotor, a robotic arm connected to a motor, or any other suitable object) within a sealed environment.

[0056] Referring to FIG. 20D, in one aspect, the sensor 20203 may utilize the principle of a magnetic circuit to detect the position of the encoder track 20202. The encoder track may have at least one encoder scale located within a sealed environment (e.g., each of the at least one encoder scales may have a predetermined pitch that may be different from the pitch of another of the at least one encoder scales). The magnetic sensing system illustrated in FIG. 20D is representatively shown and may be configured as a giant magnetoresistive sensor (GMR), or as a differential GMR (also referred to as a gradiometer that senses the difference in gradient magnetic fields between several locations), as described below. The sensor may include at least one magnetic source or ferromagnetic source 20300, a ferromagnetic encoder track 20202, and at least one magnetic sensing element or magnetic sensing member 20203H (corresponding to each magnetic source) disposed substantially between the magnetic source and the ferromagnetic track. The encoder track may be configured such that the width of the track (e.g., the track surface having encoding features thereon) may vary (e.g., up and down) in a direction orthogonal to the track plane and may extend in a plane extending radially outward having position encoding features. In other aspects, the width of the track may be arranged in an axial direction parallel to the drive shaft using encoding features that project radially (in the case of a rotary drive device) or laterally from the track plane (e.g., in a rotary drive structure, the track surface forms an annular or cylindrical shape surrounding the drive shaft T, such as tracks 20202S1’~S3’ in FIGS. 20E and 20F). Alternatively, the width of the track may be arranged in a radial direction perpendicular to the drive shaft as shown in FIG. 20A. In this aspect, the at least one magnetic sensing member 20203H may have a substantially flat (or featureless overhang) track interaction portion that interacts substantially directly with the track 20202. In other aspects, as described below, the at least one magnetic sensor may be connected to a ferromagnetic member that includes ferromagnetic features that interact with corresponding features on the track.In one aspect, the magnetic source and at least one sensing member 20203H may be attached to a printed circuit board (PCB) 20310, or may be integrally formed on the printed circuit board (PCB) 20310, and the printed circuit board is a common circuit board (e.g., common to each magnetic source and each of the at least one sensing member). In other aspects, each magnetic source and sensing member may be attached to one or more respective printed circuit boards. In one aspect, the magnetic source 20300 may be a permanent magnet disposed within an external environment. In other aspects, the magnetic source 20300 may be any suitable magnetic source, such as a coil configured to be energized to generate a magnetic field. In one aspect, the magnetic field generated by the magnetic source (the lines of force illustrated in FIG. 20D for illustrative purposes) departs from the N pole N of the magnetic source 20300 (e.g., the pole facing the opposite side of the track, in other aspects, the magnetic poles may have any suitable orientation), or (in the case of an energized coil, departs in a direction determined by the flow of current in the coil), and as shown, traverses the PCB 20310, crosses the gap (e.g., between the sensing member 20203H and the track 20202), passes through the non-ferromagnetic isolation wall 20204, and propagates to the ferromagnetic track 20202 and returns to the opposite pole S of the magnetic source 20300. When the ferromagnetic track moves relative to the magnetic source 20300, one or more magnetic field profiles are generated. The magnetic field profile may have one or more general shapes of a sine wave or a cosine wave. The sensing member 20203H is configured to sense a change in magnetic flux that is correlated with the operation of the ferromagnetic track (e.g., the magnetic field profile).

[0057] In one aspect, one or more sensing members 20203H may be any suitable giant magnetoresistive (GMR) sensing element / member capable of sensing the magnetic field at one or more locations. In other aspects, one or more sensing members may be any suitable sensing element capable of sensing a magnetic field. In one aspect, the sensing member 20203H may be configured to generate a sine wave signal that can be used, for example, to provide a phase angle related to the relative (and / or absolute) position of the ferromagnetic track 20202. Referring to FIGS. 21A and 21B, in other aspects, one or more sensing members may be differential GMR sensing members (e.g., gradiometers) configured to sense the gradient magnetic field between two locations in space. The magnetic sensing system may be a gradiometer as described above. In a gradiometer configuration, the analog output signal of each sensing member may be proportional to the magnetic field gradient between two points in space. FIG. 21A illustrates a representative gradiometer sensing member 20203H' that includes magnetoresistive elements MREs that can be configured to form a Wheatstone bridge, for example, resulting in a differential encoder channel. As can be appreciated, the configuration of the MREs (e.g., R1-R4) on the gradiometer sensing member may be specific to the encoder track and the encoding features on the magnetic source. FIG. 21B illustrates an exemplary gradiometer sensing member 20203H'' according to another aspect of the disclosed embodiments that includes magnetoresistive elements MREs arranged to provide two differential signals (e.g., sine / cosine) and a higher resolution encoder signal. The track pitch P (FIG. 20D) and the positions of the magnetoresistive elements MRE on the sensing members 20203H, 20203H', 20203H'' may be aligned such that differential sine and differential cosine outputs are obtained from each of the sensing members 20203H, 20203H', 20203H''.

[0058] In this aspect, the printed circuit board 20310 may include three sensing members 20503H1, 20503H2, 20503H3 (each capable of providing two differential signals) to obtain position signals from the ferromagnetic track 20202 having three scales 20202S (see, for example, FIGS. 20C and 21C). In one aspect, the sensing members 20503H1, 20503H2, 20503H3 (and other sensors described herein) may be immovably attached to the circuit board. In other aspects, the sensing members (and other sensors described herein) may be movably attached to the circuit board such that the sensing members may be adjusted with respect to their respective tracks 20202 and scales 20202S. Referring to FIGS. 20C and 21C - 21E, in one aspect, the scale 20202S represents a nonius pattern consisting of three scales, including a master scale 20202S1, a vernier scale 20202S2, and a segment scale 20202S3, but in other aspects, the ferromagnetic track may include any suitable number of scales having any suitable positional relationship with respect to each other. Here, each scale 202102S may include a pattern of ferromagnetic features 20202SE (such as slots, protrusions, etc.) that are equally spaced (for example, each scale pattern may have respective pitches P1, P2, P3). For each scale 20202S, there may be dedicated sensing members 20503H1 - 20503H3 configured to provide an analog signal output that substantially mimics, for example, sine and cosine waves. In one aspect, one or more of the sensing members 20503H1 - 20503H3 may be arranged at any suitable angles α1, α2 with respect to another one of the sensing members 20503H1 - 20503H3 and / or with respect to their respective tracks 20202S1 - 20202S3. In other aspects, the sensing members 20503H1 - 20503H3 may have any suitable positional relationship with respect to each other and / or with respect to each track 20202S1 - 20202S3.As can be appreciated, the period and number of each scale of the ferromagnetic feature portion 20202SE enable the design of tracks that can be used to decode the absolute position of a track using any suitable nonius interpolation approach.

[0059] As described above, referring to FIGS. 22A and 22B, the position feedback system described herein may be a reluctance-based sensing system substantially similar to that described in U.S. Patent No. 8,283,813, which is hereby incorporated by reference. For example, FIG. 22A shows an exemplary principle of operation of a reluctance-based sensing system. As seen in FIG. 22A, a read head, such as read head 207 (other read heads described herein may be substantially similar), positioned, for example, in an ambient environment, may include a magnetic source 2205 and a sensing element 2206 connected through a backing 2209. The magnetic source 2205 may generate a magnetic flux 2207 that propagates through the isolation wall 103 and continues, for example, through the track 209 to the sensing element 2206. The magnetic circuit may be closed by the backing 2209. The magnitude of the magnetic flux 2207 may be affected by the distance 2208 between the magnetic source 2205 and the ferromagnetic element or track 209 and is measured by the sensing element 2206. The sensing element 2206 may include one or more magnetic flux sensors that may operate based on, for example, the Hall effect principle, the magnetoresistance principle, or any other suitable principle appropriate for sensing the magnitude of the magnetic flux 2207.

[0060] In one aspect, one or more read heads may be utilized to interact with each of the absolute and / or incremental tracks 209, 210 (see, e.g., FIG. 2B) to provide a rough measurement of the absolute position of the rotor of the robotic drive and / or the high-resolution position of the rotor of the robotic drive. Referring also to FIG. 22B, an incremental sensing system 2250 is illustrated that may be used anywhere where the read head 208 and the incremental track 210 are used. In this aspect, the incremental sensing system 2250 includes two read heads 2211, 2212 that may be substantially similar to the read head 207 described above. In another aspect, any suitable number of read heads may be used. The read heads 2211, 2212 may interact with the incremental track 210 through the partition wall 103. The incremental track 210 may include a plurality of periodic features 2210 having any suitable size and shape to effect a stepwise opening and closing of the magnetic circuits of the read heads 2211, 2212 as a function of the relative angular position of the track 210 with respect to each read head 2211, 2212. In one aspect, the track 210 may be incorporated substantially directly within a moving part (such as a rotor), or in another aspect, may be fixed to the moving part in any suitable manner as a dedicated encoder disk. The signals generated by the read heads 2211, 2212 may be phase-shifted to determine the position of the incremental track 210 within a distance corresponding to one period of the periodic feature 2210 of the incremental track 210 and may be processed in any suitable manner by any suitable control device such as the control device 190.

[0061] As can be understood, for example, in addition to the incremental position measurement ability in real time (real time refers to the time limit of the operation from an event to the system response), the position feedback system described herein may include an additional configuration (see read head 207 and track 209) for absolute position detection that enables the position feedback system (which may include control device 190 and / or other suitable control devices) to uniquely identify the sectors of the incremental track that interact with the read head at any appropriate time. This absolute position detection may be used at the startup of the robot drive for periodic confirmation of position measurement and / or may be used during the operation of the robot drive in response to a request. In one aspect, referring to FIGS. 23A and 23B, the absolute track 209 may include a pattern of non-uniform sectors (which may include a gray-scale pattern such that one sensor changes state at a given time) detected by one or more read heads 207, where each sensor may represent one bit of the absolute position word. In this aspect, the absolute position track shown in FIG. 23A may provide a 5-bit absolute position resolution, but in another aspect, any appropriate position resolution, including more or fewer bits than 5 bits, may be provided. The corresponding 5-bit pattern (in this example there are 5 read heads, but in another aspect any appropriate number of read heads may be provided) formed by the state of the read heads as the track 209 rotates is shown in FIG. 23B.

[0062] As described above, the environment in which the moving part of the robot drive unit is positioned is isolated from the environment in which the stationary part of the robot drive unit is positioned. This isolation is achieved through the use of a non-magnetic isolation wall 103 or a "canshell". Note that adding, for example, a runout tolerance to the thickness of the isolation wall may impose a constraint on the minimum air gap achievable between the rotor and the stator. Also, in order to improve the efficiency of the motor, the air gap between the rotor and the stator should be minimized. However, when an isolation wall is used between the rotor and the stator (for example, to separate the atmospheric environment from the vacuum environment), the pressure difference on both sides of the isolation wall may impose a minimum thickness on the isolation wall. The above-described isolation wall 103 is integrated within the housing of the robot drive unit (for example, the stator housing). However, in another aspect of the disclosed embodiment, note that the isolation wall 2403 (see FIGS. 24A and 24B) may be integrally formed with or integrated with the stator (for example, separated from the drive unit housing) such that the stator structurally supports the isolation wall.

[0063] As shown in FIG. 24A, the stator 206 includes a drive coil 206C and is attached to the stator / drive unit housing 2405 in any suitable manner (e.g., in an ambient environment or other suitable environment). The stator / drive unit housing may have any suitable mechanism or compression member that engages and biases against a compressible seal member so that the seal member is held in place for assembly and compresses the seal member to isolate different pressures between the inside and outside of the drive unit housing. Due to the pressure difference, the isolation wall and / or the compression member of the housing may compress a suitable seal portion to seal the internal environment of the drive unit housing. The stator structure may facilitate seal compression and sealing as described herein (see, e.g., FIG. 24A). The rotor 101 is attached, for example, in an environment isolated from the ambient environment, such as a vacuum or other suitable environment. Here, the isolation wall 2403, which may be a thin film, may be attached to or in the same position as the poles or core of the stator 206 such that the stator substantially supports the isolation wall. In one aspect, the isolation wall 2403 may be integrated with the stator 206 (e.g., form a single structure or assembly with the stator 206) and / or may be structurally coupled in any suitable manner, e.g., to the inner diameter (or any other suitable portion) of the stator, using any suitable adhesive so as to lean against the stator 206. In another aspect, the isolation wall 2403 may be formed as a coating or fixed to the poles or core of the stator 206. In this aspect, the isolation wall 2403 may extend beyond the stator 206 to connect to the stator / drive unit housing 2405. As can be understood, an interface between the isolation wall 2403 and the stator / drive unit housing 2405 may be provided with any suitable seal member 2404. As shown in FIG. 24A, the isolation wall 2403 may not need to support additional structural loads other than the pressure differential load between the vacuum environment and the ambient environment (i.e., the pressure differential load is shared between the isolation wall and the stator). FIG. 24B shows another example of an isolation wall 2403', which is further integrated with the stator 206.Here, the partition wall 2403' may be substantially the same as the partition wall 2403, but in this aspect, the partition wall 2403' may substantially conform to (e.g., surround or take the shape of) a portion of the stator 206 that extends at least partially through the stator / drive unit housing 2405. In this aspect, the partition wall 2403' is supported by the stator 206 substantially anywhere where the partition wall connects to the environment (e.g., a vacuum environment) in which the rotor is positioned. Here, the seal member 2404 may be present in a plane different from the plane described above with respect to FIG. 24A in order to seal the interface between the partition wall 2403' and the stator / drive unit housing 2405 to isolate the isolated environment. In another aspect, the seal member may include or connect from the stator to the partition wall. For example, the seal member may be positioned within or on the partition wall.

[0064] Next, referring to FIGS. 25A and 25B, a sealed drive unit or actuator 2500 according to an aspect of the disclosed embodiment is shown. The rotor 2501 may be substantially the same as described above and may be positioned within a completely isolated environment. The ferromagnetic stator 2502 may be substantially the same as described above and may include a set of coil units 2503, salient poles 2505, two ferromagnetic plates 2505a and 2505b (e.g., stator plates), and a set of ferromagnetic coil cores 2506 around which the coils 2503 are mounted or wound. The non-magnetic isolation wall 2508 may be attached to the upper and lower stator plates 2505a and 2505b (to form a stator / isolation wall module) in any suitable manner, such as using mounting screws 2511, so that the stator plates extend beyond the isolation wall into the sealed or isolated environment and the coils 2506 are isolated from the sealed environment. The upper and lower seal members 2509a and 2509b, which may be any suitable seal member such as an O-ring, may be disposed along grooves or other recesses along the upper and lower surfaces of the isolation wall 2508. The upper and lower stator plates 2505a and 2505b may have features 2507a and 2507b that allow additional stator / isolation wall modules to be stacked on top of and below each other, as described in more detail below. In this aspect, each pair of coils may be wound in opposite directions with respect to each other, and there may be any suitable number of coils (eight coils are shown for illustrative purposes) that can be wound in pairs to form, for example, a four-phase motor. In another aspect, the motor may have any suitable number of phases. The poles 2504 of the rotor shown in FIG. 25A may be made of any suitable ferromagnetic material, and the resulting rotor / stator pair may form a variable or switched reluctance motor. In another aspect, the isolation wall configuration described herein may be used in a brushless DC motor with permanent magnet rotor poles, or in any other suitable motor in which the rotating part of the motor is isolated from the stationary part of the motor. In this aspect, the magnetic flux path 2512 is shown as being along the axial direction, which may reduce losses due to eddy currents.In another aspect, as described below, magnetic flux can flow radially. As seen in FIGS. 25A and 25B, since the stator plates 2505a, 2505b extend into the sealed environment beyond the isolation wall 2508, the air gap 2510 between the rotor pole 2504 and the stator pole 2505 is not restricted by any isolation wall (e.g., the interface is a substantially non-interfering interface and there is substantially no resistance to magnetic flux at the interface between the stator pole and the rotor pole), and can be made as small as permitted by mechanical crossover between parts. As a result, the motor configuration shown in FIGS. 25A and 25B can have a higher torque capacity than its counterpart where an isolation wall is disposed in the air gap 2510 between the stator and the rotor. As can be understood, the torque of the rotor 2501 may be generated by exciting the appropriate phase using the position feedback of each rotor / stator design and the curve of the torque current position such that the torque ripple inherent in the switched reluctance motor is minimized in any suitable way.

[0065] Next, referring to FIG. 25C, there is shown a two-axis sealed robot drive unit according to aspects of the disclosed embodiments using, for example, the stator / isolation wall module described above with respect to FIGS. 25A and 25B. Also, as described above, all of the moving parts of the motor are positioned within the isolation environment. In this aspect, the drive unit includes a bottom plate 2514 that guides or supports a central stationary shaft 2515. The inner drive shaft 2517a may be attached to the shaft 2515 in any suitable manner, such as using bearings 2516a and 2522a that allow the inner shaft 2517a to rotate relative to the stationary shaft 2515. The rotor 2513c may be firmly attached to the inner shaft 2517a and may be propelled along the direction of rotation by the stator 2513a, for example, by electromagnetic force. As can be understood, the pair of stator 2513a and rotor 2513c forms a motor that generates an operating torque with respect to the inner shaft 2517a. The outer drive shaft 2517b may be attached to the inner drive shaft 2517a in any suitable manner, such as by bearings 2516b and 2522b, for example, to provide relative rotation between the shafts 2517a and 2517b. The outer shaft 2517b may be propelled in a manner similar to that described above so that the stator 2513b and rotor 2513d, which form a second motor, generate an operating torque to rotate the outer shaft 2517b. One or more position feedback sensors for the inner shaft 2517a and the outer shaft 2517b, which may be substantially similar to those described above, are positioned to track the movement of each shaft. Here, the position feedback system is shown as an optical feedback system, but in another aspect, the feedback system may be a reluctance-based feedback system as described above such that the position feedback system operates without using any feedthroughs or viewports at all. Here, the position feedback system may include an encoder disk 2518a that is fixed to the inner shaft 2517a in any suitable manner, such as using a clamp 2519a.The signals of the reading head 2525a (including the emitter 2523a and the receiver 2524a) are sent outside the isolation environment in any suitable way across the isolation wall / stator housing 2520a. The position feedback operation of the outer shaft is the same as that of the inner shaft described above, and may include a reading head 2525b including an emitter 2523b and a receiver 2524b, and an encoder disk 2518b (fixed to the outer shaft 2517b). The stators 2513a and 2513b may be respectively attached to the isolation walls / stator housings 2520a and 2520b. Each isolation wall / stator housing is connected to each stator via a recessed feature (or equivalent interface), and any suitable static sealing element or member such as an O-ring. The upper surface flange 2521 and the bottom plate 2514 are also connected to the stator 2513b and the isolation wall / stator housing 2520a respectively in any suitable way. The inner shaft 2517a and the outer shaft 2517b construct a two-degree-of-freedom system that can be used to drive a two-link manipulator (for example, a robotic arm) positioned within the isolation environment. As can be understood, additional motors may be stacked to form a drive unit having any suitable number of degrees of freedom. There is no isolation wall between the ferromagnetic poles of the rotor and the stator (for example, the stator plates 2505a, 2505b extend into the isolation environment beyond the isolation wall 2508), which enables better torque performance compared to the conventional "canceling" option where the isolation wall is placed between the stator and the rotor.

[0066] Next, referring to FIGS. 26A and 26B, a sealed drive unit 2600 according to an aspect of the disclosed embodiment is shown. The drive unit 2600 may be substantially the same as the drive unit 2500 described above except as noted. In this aspect, the coil 2603 of the stator 2606 is attached in a different orientation from the coil 2506. However, since the magnetic flux path 2612 is substantially the same as the magnetic flux path 2512, the drive units 2500, 2600 operate using the same principle.

[0067] Referring to FIGS. 27A and 27B, a sealed drive unit 2700 according to an aspect of the disclosed embodiment is shown. The drive unit 2600 may be substantially the same as the above-described drive unit 2500 except as noted. In this aspect, the coils 2703a and 2703b of the stator 2706 may be mounted radially and axially. However, the resulting magnetic flux path 2712 is substantially the same as the magnetic flux path 2512.

[0068] Next, referring to FIGS. 28A - 28C, a sealed drive unit 2800 according to an aspect of the disclosed embodiment is shown. The drive unit 2800 may be substantially the same as the above-described drive unit 2500 except as noted. In this aspect, the coil unit 2503 can be removably mounted substantially directly on the partition wall / stator housing 2520', reducing the number of drive motor components and allowing for scalability with different rotor diameters (e.g., the coil unit 2503 forms a stator module that can be fixed to a housing having any suitable diameter to form a stator having a diameter corresponding to the housing diameter). As can be understood, a suitable static seal member 2809 may be disposed, for example, between the flanges of each stator plate 2505a, 2505b and the partition wall / stator housing 2520'. The direction of the magnetic flux 2812 in this aspect may be substantially the same as the direction of the above-described magnetic flux 2512. Also referring to FIG. 28D, a two-axis sealed drive unit assembly including stacked drive units 2500 is shown. The drive unit assembly of FIG. 28D may be substantially the same as that shown in FIG. 25C except as noted. Here, the partition wall / stator housing 2520' may be used as a common mounting structure for each stator 2513a', 2513b'. Note that the partition wall / stator housing 2520' may be used as a housing for supporting any suitable stationary components of the drive unit, such as the position feedback devices 2523a, 2524a, 2525a and 2523b, 2524b, 2525b.

[0069] As can be understood, the stator poles and the rotor poles may be arranged such that the air gaps positioned between the poles are arranged radially or axially with respect to the rotation axis of the rotor. For example, in FIGS. 24A to 28B, the arrangement of the stator poles and the rotor poles is such that the air gaps are arranged axially (e.g., such that there is a radial magnetic flux flow through the air gap between the stator pole and the rotor pole). In another aspect, referring to FIGS. 28E, 28F and 28G, the stator and the rotor may be arranged such that the air gap between the stator pole and the rotor pole is arranged radially (e.g., such that there is an axial magnetic flux flow 2898 through the air gap between the stator pole and the rotor pole). For example, referring to FIGS. 28E and 28F, the stator coil unit 2503 may be substantially the same as that described above with respect to FIGS. 25A to 28D, or any other suitable coil unit described herein. The coil unit 2503 may be sized such that the stator plate / extension overlaps the rotor pole axially and forms a radial air gap 2899, substantially between the stator plates 2505a, 2005b, and / or between the stator extensions (described below) such that the rotor pole 2504 is disposed therebetween. In one aspect, the isolation wall / seal portion 2403' may be substantially the same as the seal portion 2403 through which the stator plates 2505a, 2505b do not extend through the stator housing 2405. In another aspect, the isolation wall may be substantially the same as the above-described isolation walls 2508 and / or 2520' through which the stator plate extends through the stator housing / isolation wall. Also referring to FIGS. 28H and 28I, the rotor pole may have any suitable shape for receiving magnetic flux from the stator pole. In this aspect, the rotor pole 2504' may be substantially in a "C" or channel shape such that the plate 2504P' of the rotor pole is substantially aligned with each of the stator plates 2505a, 2505b, having a core 2504C' of the rotor pole and a plate 2504P' of the rotor pole extending / drooping from the core 2504C' of the rotor pole.Here, there is a radial magnetic flux flowing through the air gap 2899 between the stator plates 2505a, 2505b and the rotor pole plate 2504P'. However, in another aspect, the rotor pole core and the rotor pole plate may be arranged to provide an axial magnetic flux flow through the air gap in a manner substantially similar to that described above.

[0070] The aspects of the disclosed embodiments have a flux path along the axial direction (longitudinal or perpendicular), but it should be understood that the aspects of the disclosed embodiments are not limited to the direction of the magnetic flux, and either an axial or a radial machine can be utilized. For example, FIGS. 29A - 29C show a radial magnetic flux sealing device 2900 according to aspects of the disclosed embodiments. In this aspect, the stator 2902 includes a ferromagnetic stator core 2902C having stator poles 2902P, 2902P' each including a coil 2903 at each stator pole. Each stator pole 2902P, 2902P' may be connected to the isolation wall / stator housing 2520' in a substantially similar manner as described above and include respective stator pole extensions 2902E, 2902E' that extend beyond the isolation wall / stator housing 2520'. In one aspect, the stator pole extensions 2902E may be removable from their respective stator poles 2902P. Each stator pole extension 2902E may be attached to the isolation wall / stator housing 2520' in any suitable manner, such as using a clamp 2511, so that each stator pole extension 2902E is aligned with its respective pole 2902P of the stator 2902. Each stator pole extension 2902E may be in substantial contact with and / or in close proximity to (e.g., with a minimal gap) its respective stator pole 2902P so that there is substantially no resistance in the flux path at the interface between the stator pole extension and its respective stator pole. In another aspect, the stator pole extensions may be integral (e.g., a single-piece configuration) with their respective stator poles. In this aspect, for illustrative purposes only, the stator includes a set of eight stator modules 2902 having coils a, a', b, b', c, c', d and d', but in another aspect, the stator may include any suitable number of stator modules having any suitable number of coils. Here, each pair of diametrically opposed coils can be wired in any suitable manner, such as in series, to form a four-phase machine. In other aspects, any suitable number of phases may be provided. In this aspect, the flux path 2912 is shown along the radial direction when phase a - a' is excited.As shown in FIG. 29A, magnetic flux 2912 flows from stator pole 2902P, along pole extension 2902E, across air gap 2510, reaches rotor pole 2504P, moves along the outer periphery of the rotor, and reaches the opposite rotor pole 2504B, pole extension 2902E', and stator pole 2902P'. The magnetic flux is "closed" by a set of return paths along the ferromagnetic core 2902C of the stator. In one aspect, stator 2902 can be made by stacking any suitable laminated ferromagnetic sheets.

[0071] Referring to FIGS. 30A and 30B, in another aspect of the disclosed embodiment, substantially similar to that described above with respect to FIGS. 29A - 29C, coil 2903 may be integrated with stator pole extension 3002E. In this aspect, stator core 2902C may include a laminated stack that can be pre - assembled (e.g., aligned and welded or fixed in any suitable manner that may be substantially similar to that described above for the laminated rotor). In another aspect, the stator core may be a solid ferromagnetic core formed in any suitable way.

[0072] FIG. 31 shows a radial magnetic flux sealed drive unit 3100 according to an aspect of the disclosed embodiment. In this aspect, the drive unit includes a segmented stator 3102, but is otherwise substantially similar to drive unit 2900 described above. In another aspect, stator pole extension 2902E may be substantially similar to stator pole extension 3002E with an integral coil 2903. In this aspect, stator poles 2902P may not be uniformly distributed around the outer periphery of stator 3102 (e.g., have a non - uniform distribution). Rotor poles 2504 may be aligned with stator poles 2902P in such a way that rotor poles 2504 and stator poles 2902P are not directly opposite each other (e.g., not oriented directly opposite). Here, magnetic flux path 3112 is a radial magnetic flux path along the face of the rotor.

[0073] FIG. 31 shows a sealed drive unit 3200 according to another aspect of the disclosed embodiment. The drive unit 3200 may be substantially the same as the drive unit 3100 except as noted. Here, one coil 2903’ is excited for each of the phases a, b, c, d, but in another aspect, two or more coils may be excited for each phase. This aspect may allow for space for larger coils, for example, by utilizing the arc length of the segmented stator elements, without substantially increasing the stack height of the stator 2902. In another aspect, for example, the coil positions of FIGS. 31 and 32 may be combined to maximize the utilization of the coil space as shown in FIG. 33.

[0074] In another aspect of the disclosed embodiment, for example, a sealed drive unit 3400 may be provided in which the isolation wall is structurally supported on the isolation environment side of the isolation wall by any suitable seal support member. For example, referring to FIG. 34, a drive unit 3400 is shown that utilizes stator pole extensions that are substantially the same as the drive units described above with respect to FIGS. 25A-33. In this aspect, the drive unit 3400 includes a sealing casing or isolation wall 3451 that is interposed or disposed between the stator pole 3503P and the stator pole extension 3503E. In this aspect, any suitable seal support member 3450 may be disposed within the isolation environment. The seal support member 3450 may be composed of any suitable material and may have any suitable shape. The seal support member 3450 may be configured to accommodate a set of ferromagnetic stator pole extensions 3503E such that the stator pole extensions 3450E are substantially aligned with their respective stator poles 3503P. In one aspect, the stator pole extensions may be embedded within or integral with the seal support member (e.g., forming a single piece of a single member). In one aspect, the stator pole extensions may be removably attached within or to the seal support member. Note that the stator pole extensions are positioned within the isolation environment and are separated from their respective stator poles (positioned in the ambient environment) by the isolation wall 3451, which is a very thin can seal.

[0075] In one aspect, a partition wall is disposed between the stator pole extension and its respective stator pole to separate the stator pole extension from its respective stator pole (e.g., partition wall 3451 penetrates the stator), and one or more extremely thin cansils or partition walls 3451 may be disposed around the outer peripheral surface of the seal support member 3450. As can be understood, there may be no operation between the stator pole extension and its respective stator pole, and similarly there may be no operation between the partition wall and the stator. In one aspect, the partition wall 3451 may be one or more non-magnetic cylindrical sleeves of any suitable material such as stainless steel, or any other suitable material that can provide a seal in a vacuum environment or other isolation environment. In another aspect, the partition wall may be formed by applying a coating or other film to the seal support member / stator pole extension assembly. Here, the non-magnetic sleeve may provide a seal for each stator pole of the drive unit 3400. For example, the magnetic sleeve may surround the outer peripheral surface of the seal support member at the level of the seal support member that corresponds to the stator poles of each motor such that the stator poles belonging to a common motor also share a common partition wall. If the drive unit 3400 includes, for example, two or more motors in a stacked arrangement, the partition wall may be provided for each motor such that the partition walls form a band that is arranged vertically on the outer peripheral surface of the seal support member as described below. In another aspect, the partition wall may be common to two or more motors of the drive unit assembly. In yet another aspect, the partition wall may be a segmented wall that may have corresponding partition wall sections (e.g., disposed on the seal support member) that are different for each stator pole from the partition walls of other stator poles.

[0076] The partition wall 3451 may be extremely thin and may have a thickness of about 30 μm, but in another aspect, the thickness of the partition wall 3451 may be greater than or less than 30 μm. As described above, the partition wall 3451 is disposed around the outer peripheral surface of the seal support member 3450 that structurally supports the partition wall 3451 when the pressure in the isolation environment deviates from atmospheric pressure. For example, when a pressure difference is built between the vacuum pressure in the isolation environment and the atmospheric pressure outside the isolation environment, the partition wall 3451 is pressed against the seal support member 3450 by the differential pressure so that the seal support member 3450 and the stator pole extension element 3503E substantially prevent the collapse of the partition wall 3451. The magnetic flux between the stator and the rotor faces the partition wall (disposed between the stator poles and the stator pole extensions) as well as the air gap of the rotor / stator, but note that the pure losses are minimized by the small gap between the stator and the rotor and the very small thickness of the partition wall.

[0077] Referring to FIG. 35, a stackable motor module 3400M is shown in accordance with aspects of the disclosed embodiments. FIG. 35 shows a cross-sectional view A-A of the drive unit 3400. In one aspect, the stackable motor module 3400M includes an array of stator pole extensions 3503E housed within a ring-shaped (or other suitable shape) seal support member having an upper surface 3450T' and a bottom surface 3450B' (the terms upper and bottom surfaces are used for illustrative purposes only and in another aspect, any suitable spatial terms may be assigned to surfaces 3450T', 3450B'), and a partition wall 3451 fixed to the seal support member. When the modules 3400M are stacked, static seal members 2509 may be disposed on each of the surfaces 3450T', 3450B' so that there is substantially no air flow between the isolated environment and the atmospheric environment. The partition wall 3451 is disposed around the outer peripheral surface of the seal support member 3450' such that any gap between the stator pole extension 3503E and the seal support member 3450' is covered by the partition wall and may be fixed to the outer peripheral surface in any suitable manner. A static seal member 3509' may also be disposed between the partition wall 3451 and the seal support member 3450' to provide a seal between the partition wall and the seal support member. In this aspect, the stator 3503 may be positioned around the motor module 3400M and the rotor 3501 may be positioned within the motor module 3400M to form a drive motor. In another aspect, the motor module 3400M may include a stator 3503 (which may be fixed to the seal support member and / or the partition wall in any suitable manner). In yet another aspect, the rotor 2501 may also be included in the motor module 3400M.

[0078] FIG. 36 shows motor modules 3400M1, 3400M2 (substantially the same as motor module 3400M) stacked vertically to form a drive unit for two-axis movement. As seen in FIG. 36, each module 3400M1, 3400M2 includes respective partition walls 3451 such that partition walls for bands are arranged vertically along the combined length of seal support members 3450’ (which can form seal support members 3450). Here, the number of static seal members 3509’ between the partition walls 3451 and the respective seal support members 3450 depends on the number of drive shafts. In another aspect, as shown in FIG. 37, the number of static seal members may be independent of the number of drive shafts. FIG. 37 shows a stacked drive unit for two-axis movement substantially the same as that shown in FIG. 36. However, here, a single or a piece of partition wall 3451’ (e.g., a continuous seal casing) is provided on the outer peripheral surface of the seal support member 3450’ such that the stacked seal support members 3450 share a common partition wall 3451’ and the common partition wall 3451’ extends across one or more motors. In this aspect, note that the partition wall also provides to seal the interface between the stacked seal support members such that the seal member 3509 arranged between the seal support members can be omitted.

[0079] According to one or more aspects of the disclosed embodiments, a conveying device is provided. The conveying device includes a housing, a drive unit attached to the housing, and at least one conveying arm connected to the drive unit. The drive unit includes at least one rotor having at least one salient pole of a ferromagnetic material and arranged in an isolated environment, at least one stator having at least one salient pole with a corresponding coil unit and arranged outside the isolated environment, and at least one seal part configured to isolate the isolated environment and integral with at least one stator. At least one salient pole of at least one stator and at least one salient pole of at least one rotor form a closed magnetic flux circuit between at least one rotor and at least one stator.

[0080] According to one or more aspects of the disclosed embodiments, at least one seal portion comprises a film attached to at least one stator.

[0081] According to one or more aspects of the disclosed embodiments, at least one seal portion abuts at least one stator.

[0082] According to one or more aspects of the disclosed embodiments, at least one stator structurally supports at least one seal portion.

[0083] According to one or more aspects of the disclosed embodiments, at least one seal portion conforms to the shape of at least one stator.

[0084] According to one or more aspects of the disclosed embodiments, at least one rotor and at least one stator form a stacked motor or a motor in which one is radially nested within the other.

[0085] According to one or more aspects of the disclosed embodiments, the conveying device further includes at least one reluctance-based encoder track disposed on each of at least one rotor, and at least one reluctance-based position feedback sensor configured to interact with the at least one reluctance-based encoder track.

[0086] According to one or more aspects of the disclosed embodiments, at least one rotor is coupled to a coaxial drive shaft configuration to drive at least one conveying arm.

[0087] According to one or more aspects of the disclosed embodiments, at least one stator is a segmented stator.

[0088] According to one or more aspects of the disclosed embodiments, the drive unit is configured as an axial flux flow drive unit or a radial flux flow drive unit.

[0089] According to one or more aspects of the disclosed embodiments, at least one rotor includes laminated salient poles.

[0090] According to one or more aspects of the disclosed embodiments, at least one stator includes laminated salient poles.

[0091] According to one or more aspects of the disclosed embodiments, at least one rotor includes a drive member interface, the drive unit further includes a drive transmission member, and the drive transmission member interacts with the at least one rotor at the drive member interface such that the drive member interacts with the laminated salient poles and fixes the laminated salient poles to the drive member.

[0092] According to one or more aspects of the disclosed embodiments, the laminated salient poles are fixed to the drive member so as to be arranged axially with respect to the drive member.

[0093] According to one or more aspects of the disclosed embodiments, the laminated salient poles are fixed to the drive member so as to be arranged radially with respect to the drive member.

[0094] According to one or more aspects of the disclosed embodiments, the drive unit includes a Z-axis drive motor connected to the housing.

[0095] According to one or more aspects of the disclosed embodiments, a conveying device is provided. The conveying device includes a housing, a driving unit attached to the housing, and at least one conveying arm connected to the driving unit. The driving unit includes at least one rotor having at least one salient pole of a ferromagnetic material and disposed in an isolated environment, at least one stator having salient poles each provided with a coil unit and disposed outside the isolated environment, and at least one stator salient pole extension and at least one salient pole of the rotor are disposed in the isolated environment so as to form a closed magnetic flux circuit between the at least one stator and the at least one rotor, and at least one stator salient pole extension aligned with each stator salient pole, and at least one seal portion disposed between each stator pole and its respective stator salient pole extension and configured to isolate the isolated environment.

[0096] According to one or more aspects of the disclosed embodiments, the driving unit further includes a seal support member having an inner surface disposed in the isolated environment and an outer surface facing the opposite side of the isolated environment, and at least one seal portion is disposed on or adjacent to the outer surface, and the seal support surface is configured to structurally support at least one seal portion.

[0097] According to one or more aspects of the disclosed embodiments, the seal support member is configured to accommodate at least one stator salient pole extension.

[0098] According to one or more aspects of the disclosed embodiments, the at least one stator and the at least one rotor form a stacked motor, and at least one seal portion is common to each of the stacked motors.

[0099] According to one or more aspects of the disclosed embodiments, the at least one stator and the at least one rotor form a stack of motors, and at least one seal portion includes a seal portion for each motor that is different from the seal portions of the other motors in the stack of motors.

[0100] According to one or more aspects of the disclosed embodiments, at least one stator pole extension and at least one rotor are arranged such that the at least one stator pole extension and the at least one rotor have an interface without obstacles.

[0101] According to one or more aspects of the disclosed embodiments, each stator and its respective rotor form a motor module configured to be stacked with other motor modules.

[0102] According to one or more aspects of the disclosed embodiments, the drive unit is configured as an axial flux current drive unit or a radial flux current drive unit.

[0103] According to one or more aspects of the disclosed embodiments, at least one rotor includes laminated poles.

[0104] According to one or more aspects of the disclosed embodiments, at least one rotor includes a drive member interface, the drive unit further includes a drive transmission member, and the drive transmission member interacts with the at least one rotor at the drive member interface such that the drive member interacts with the laminated poles and fixes the laminated poles to the drive member.

[0105] According to one or more aspects of the disclosed embodiments, the laminated poles are fixed to the drive member so as to be arranged axially with respect to the drive member.

[0106] According to one or more aspects of the disclosed embodiments, the laminated poles are fixed to the drive member so as to be arranged radially with respect to the drive member.

[0107] According to one or more aspects of the disclosed embodiments, at least one stator includes laminated poles.

[0108] According to one or more aspects of the disclosed embodiments, the drive unit includes a Z-axis drive motor connected to the housing.

[0109] According to one or more aspects of the disclosed embodiments, the conveying device further includes at least one reluctance-based encoder track disposed on each of at least one rotor, and at least one reluctance-based position feedback sensor configured to connect to the at least one reluctance-based encoder track.

[0110] According to one or more aspects of the disclosed embodiments, at least one rotor is connected to a coaxial drive shaft configuration to drive at least one conveying arm.

[0111] According to one or more aspects of the disclosed embodiments, a conveying device is provided. The conveying device includes a housing, a drive unit attached to the housing, and at least one conveying arm connected to the drive unit. The drive unit includes at least one rotor having at least one salient pole of a ferromagnetic material, and at least one stator including a stator core, a protruding upper plate, a protruding bottom plate, and a coil unit associated with each pair of the protruding upper plate and the bottom plate, wherein the protruding upper plate and the protruding bottom plate are connected to the stator core and spaced apart by the stator core, and at least one stator configured to interact with at least one salient pole of at least one rotor to form a closed magnetic flux circuit between the at least one stator and the at least one rotor, and a partition wall disposed between the upper plate and the bottom plate and configured to isolate the stator core from an isolation environment in which at least one conveying arm operates.

[0112] According to one or more aspects of the disclosed embodiments, each rotor and respective stator are configured as a motor module, and the motor module is configured to interact with other motor modules to form a drive unit having stacked motors.

[0113] According to one or more aspects of the disclosed embodiments, the drive unit is configured as an axial flux current drive unit or a radial flux current drive unit.

[0114] According to one or more aspects of the disclosed embodiments, the drive unit includes a Z-axis drive motor connected to the housing.

[0115] According to one or more aspects of the disclosed embodiments, the conveying device further includes at least one reluctance-based encoder track disposed on each of at least one rotor, and at least one reluctance-based position feedback sensor configured to connect to the at least one reluctance-based encoder track.

[0116] According to one or more aspects of the disclosed embodiments, at least one rotor is coupled to a coaxial drive shaft configuration to drive at least one conveying arm.

[0117] According to one or more aspects of the disclosed embodiments, a conveying device is provided. The conveying device includes a housing, a driving unit attached to the housing, and at least one conveying arm connected to the driving unit. The driving unit includes at least one laminated rotor having salient poles laminated with a ferromagnetic material, which is arranged in an isolated environment, and the at least one laminated rotor is isolated from the isolated environment. The driving unit further includes at least one stator having at least one salient pole and each coil unit provided outside the isolated environment so that at least one salient pole of the at least one laminated rotor and the salient pole of the at least one stator form a closed magnetic flux circuit between the at least one stator and the at least one rotor, and at least one sealing portion configured to isolate the isolated environment.

[0118] According to one or more aspects of the disclosed embodiments, the at least one laminated rotor includes a drive member interface, and the driving unit further includes a drive transmission member, and the drive transmission member interacts with the laminated salient poles of the drive member at the drive transmission member interface so as to fix the laminated salient poles to the drive transmission member and interacts with at least one rotor.

[0119] According to one or more aspects of the disclosed embodiments, the laminated salient poles are fixed to the drive transmission member so as to be arranged axially with respect to the drive transmission member.

[0120] According to one or more aspects of the disclosed embodiments, the laminated salient poles are fixed to the drive transmission member so as to be arranged radially with respect to the drive transmission member.

[0121] According to one or more aspects of the disclosed embodiments, the at least one laminated rotor is embedded in a shield configured to isolate the at least one laminated rotor from the isolated environment.

[0122] According to one or more aspects of the disclosed embodiments, the at least one sealing portion is integral with the at least one stator.

[0123] According to one or more aspects of the disclosed embodiments, at least one seal portion comprises a membrane attached to at least one stator.

[0124] According to one or more aspects of the disclosed embodiments, at least one seal portion abuts at least one stator.

[0125] According to one or more aspects of the disclosed embodiments, at least one stator structurally supports at least one seal portion.

[0126] According to one or more aspects of the disclosed embodiments, at least one seal portion conforms to the shape of at least one stator.

[0127] According to one or more aspects of the disclosed embodiments, at least one stator includes a stator core, an upper plate, and a bottom plate, the upper plate and the bottom plate form salient poles, are connected to and spaced apart from the stator core, are configured to interact with at least one laminated rotor, at least one seal portion is between the upper plate and the bottom plate, and is configured to isolate the stator core from an isolation environment in which at least one transfer arm operates.

[0128] According to one or more aspects of the disclosed embodiments, the drive portion further includes at least one stator salient pole extension disposed within the isolation environment and aligned with respective salient poles of the stator, and at least one seal portion is disposed between each salient pole of the stator and the respective stator salient pole extension.

[0129] According to one or more aspects of the disclosed embodiments, the drive unit further includes a seal support member having an inner surface disposed in an isolated environment and an outer surface facing the opposite side of the isolated environment, and at least one seal portion is disposed on or adjacent to the outer surface, and the seal support surface is configured to structurally support at least one seal portion.

[0130] According to one or more aspects of the disclosed embodiments, the seal support member is configured to accommodate at least one stator pole extension.

[0131] According to one or more aspects of the disclosed embodiments, a conveying device is provided. The conveying device includes a housing, a drive unit attached to the housing, and at least one conveying arm connected to the drive unit. The drive unit includes at least one vacuum-compatible laminated rotor having laminated rotor poles of a ferromagnetic material and disposed in an isolated environment, and at least one vacuum-compatible laminated rotor includes a set of laminates of alternately stacked ferromagnetic layers and non-conductive layers. The drive unit further includes at least one stator having at least one stator pole with each coil unit disposed outside the isolated environment, and each of the laminated rotor poles interacts with at least one rotor pole to form a closed magnetic flux circuit between at least one vacuum-compatible laminated rotor and at least one stator, and at least one seal portion configured to isolate the isolated environment.

[0132] According to one or more aspects of the disclosed embodiments, the drive unit includes at least one drive shaft and a holding member configured to attach at least one vacuum-compatible laminated rotor to at least one drive shaft and clamp the alternately stacked laminates together.

[0133] According to one or more aspects of the disclosed embodiments, the alternately stacked laminates are adhesively bonded together.

[0134] According to one or more aspects of the disclosed embodiments, at least one seal portion is integral with at least one stator.

[0135] According to one or more aspects of the disclosed embodiments, at least one seal portion comprises a membrane attached to at least one stator.

[0136] According to one or more aspects of the disclosed embodiments, at least one seal portion abuts at least one stator.

[0137] According to one or more aspects of the disclosed embodiments, at least one stator structurally supports at least one seal portion.

[0138] According to one or more aspects of the disclosed embodiments, at least one seal portion conforms to the shape of at least one stator.

[0139] According to one or more aspects of the disclosed embodiments, at least one stator includes a stator core, an upper plate, and a bottom plate, the upper plate and the bottom plate form stator poles, are connected to and spaced apart by the stator core, are configured to interact with at least one vacuum-compatible laminated rotor, at least one seal portion is between the upper plate and the bottom plate, and is configured to isolate the stator core from an isolation environment in which at least one transfer arm operates.

[0140] According to one or more aspects of the disclosed embodiments, the drive portion further includes at least one stator pole extension disposed within the isolation environment and aligned with respective stator poles, and at least one seal portion is disposed between each stator pole and its respective stator pole extension.

[0141] According to one or more aspects of the disclosed embodiments, the drive unit further includes a seal support member having an inner surface disposed in an isolated environment and an outer surface facing the opposite side of the isolated environment, at least one seal portion is disposed on or adjacent to the outer surface, and the seal support surface is configured to structurally support at least one seal portion.

[0142] According to one or more aspects of the disclosed embodiments, the seal support member is configured to accommodate at least one stator pole extension.

[0143] According to one or more aspects of the disclosed embodiments, at least one seal portion is integral with the structure of at least one stator.

[0144] According to one or more aspects of the disclosed embodiments, at least one seal portion is supported by the structure of at least one stator.

[0145] According to one or more aspects of the disclosed embodiments, the variable reluctance motor assembly includes a casing having a drum structure, a stator mounted within the drum structure, and a rotor mounted within the drum structure and interacting with the stator, the casing including a common reference for forming a stator interface surface configured to support the stator and position the stator and the rotor relative to each other to create a predetermined gap between the stator and the rotor.

[0146] According to one or more aspects of the disclosed embodiments, the variable reluctance motor assembly further includes an isolation wall 2403 supported by the stator such that the isolation wall is positioned at a predetermined position relative to the common reference and the rotor.

[0147] According to one or more aspects of the disclosed embodiments, the variable reluctance motor assembly further includes a sensor track connected to the rotor, and a sensor attached to the casing at a predetermined position relative to a common reference to create a predetermined gap between the sensor and the sensor track. The stator, rotor, sensor, and sensor track are positioned relative to a common reference and are dependent on the common reference.

[0148] According to one or more aspects of the disclosed embodiments, the casing is a single member that forms a drum structure and has slots formed therein for one or more of the sensor, the control panel, and the drive unit connector.

[0149] According to one or more aspects of the disclosed embodiments, the casing is an integral assembly formed by two or more hoop members connected to each other to form a drum structure.

[0150] According to one or more aspects of the disclosed embodiments, the casing of the variable reluctance motor includes an outer surface and an inner surface. The outer surface and the inner surface form a drum structure. The inner surface forms a stator interface surface configured to position the stator and the rotor within the casing relative to each other to create a predetermined gap between the stator and the rotor, and includes a common reference.

[0151] According to one or more aspects of the disclosed embodiments, the inner surface includes a rotor interface surface positioned relative to a common reference such that the stator and the rotor are positioned and supported from the common reference.

[0152] According to one or more aspects of the disclosed embodiments, the drum structure includes a sensor interface surface configured to support a sensor with respect to a sensor track connected to the rotor and create a predetermined gap between the sensor and the sensor track, and the sensor interface surface is positioned with respect to a common reference such that the stator, rotor, and sensor are positioned and supported from the common reference.

[0153] According to one or more aspects of the disclosed embodiments, the sensor interface surface is formed as a slot within the drum structure.

[0154] According to one or more aspects of the disclosed embodiments, the slot is configured to accommodate the sensor and the motor control panel.

[0155] According to one or more aspects of the disclosed embodiments, the drum structure is a single member in which slots are formed for one or more of a sensor, a control panel, and a drive unit connector.

[0156] According to one or more aspects of the disclosed embodiments, the drum structure is an integral assembly formed by two or more hoop members connected to each other.

[0157] It should be understood that the above description is merely illustrative of aspects of the disclosed embodiments. Those skilled in the art may devise various alternative and modified examples without departing from the aspects of the disclosed embodiments. Accordingly, the aspects of the disclosed embodiments are intended to cover all such alternatives, modifications, and variations that fall within the scope of the appended claims. Further, the fact that different features are detailed in different dependent or independent claims does not mean that combinations of these features cannot be used advantageously, and such combinations remain within the scope of the aspects of the present invention.

Claims

1. A housing, a drive unit attached to the housing, and at least one transport arm connected to the drive unit comprising a transport device, wherein the drive unit has a partition wall with an isolation environment therein, at least one laminated rotor disposed within the isolation environment, the laminated rotor having salient poles formed by laminating a magnetic permeability material completely embedded by an outer shell, the outer shell preventing exposure of the laminated salient poles of the magnetic permeability material to the isolation environment, at least one laminated rotor; at least one stator having a plurality of salient poles each provided with a coil unit disposed outside the isolation environment, each salient pole of the plurality of salient poles of the at least one stator interacting with the laminated salient poles of the at least one laminated rotor to form a closed magnetic flux circuit between the salient poles of the at least one stator and the laminated salient poles of the at least one rotor interacting with the salient poles of the at least one stator, the salient poles of the at least one stator extending at least partially through the partition wall, at least one stator; at least one thin film seal portion, the at least one thin film seal portion being disposed with respect to the salient poles of the at least one stator, the at least one thin film seal portion and the salient poles of the at least one stator isolating the isolation environment from the environment outside the isolation environment in combination with each other, and the load of the pressure differential between the isolation environment and the environment outside the isolation environment being shared by both the at least one thin film seal portion and the salient poles of the at least one stator, at least one thin film seal portion including a transport device.

2. The at least one laminated rotor includes a drive member interface, the drive unit further includes a drive transmission member, The drive transmission member is connected to the laminated salient poles and fixed to the laminated salient poles, and is connected to the at least one laminated rotor at the drive member interface so as to fix the laminated salient poles to the drive transmission member. The transport device according to Claim 1.

3. The transport device according to Claim 2, wherein the laminated salient poles are fixed to the drive transmission member and arranged axially with respect to the drive transmission member.

4. The conveying device according to claim 2, wherein the stacked salient poles are fixed to the drive transmission member and arranged radially with respect to the drive transmission member.

5. The conveying device according to claim 1, wherein the at least one laminated rotor is embedded in a shielding body configured to isolate the at least one laminated rotor from the isolation environment.

6. The conveying device according to claim 1, wherein the at least one thin film seal portion is integral with the at least one stator.

7. The conveying device according to claim 1, wherein the at least one thin film seal portion is structurally coupled to the at least one stator such that the at least one stator supports the at least one thin film seal portion.

8. The conveying device according to claim 1, wherein the at least one stator structurally supports the at least one thin film seal portion.

9. The conveying device according to claim 1, wherein the shape of the at least one thin film seal portion is at least partially in the shape of a part of the at least one stator extending through the isolation wall such that the at least one thin film seal portion is supported by the at least one stator at all locations where the at least one thin film seal portion contacts the isolation environment.

10. The at least one stator includes a stator core, an upper plate, and a bottom plate, wherein the upper plate and the bottom plate form salient poles, are connected to the stator core, and are spaced apart by the stator core, and are configured to interact with the at least one laminated rotor, The conveying device according to claim 1, wherein the at least one thin film seal portion is between the upper plate and the bottom plate and is configured to isolate the stator core from an isolation environment in which the at least one conveying arm operates.

11. The drive unit further includes a plurality of stator salient pole extensions disposed within the isolation environment and aligned with respective salient poles of the stator, and the at least one thin film seal portion is disposed between each salient pole of the stator and a respective stator salient pole extension.

12. The drive unit further includes a seal support member having an inner surface facing the isolation environment and an outer surface facing the side opposite to the isolation environment, the at least one thin film seal portion is disposed on or adjacent to the inner surface, the inner surface is configured to structurally support the at least one thin film seal portion, and the thin film seal portion structurally supported by the inner surface forms the isolation wall. The transport device according to claim 11.

13. The transport device according to claim 12, wherein the seal support member is configured to accommodate the stator pole extension.

14. A housing, A drive unit attached to the housing, And at least one transport arm connected to the drive unit A transport device comprising: the drive unit includes An isolation wall having an isolation environment therein, At least one vacuum-compatible laminated rotor having a plurality of laminated rotor poles of a magnetic permeable material disposed within the isolation environment, the at least one vacuum-compatible laminated rotor including a set of laminates having alternating ferromagnetic and non-conductive layers, At least one stator having a plurality of stator poles each provided with a coil unit disposed outside the isolation environment, the stator poles extending at least partially through the isolation wall, at least one stator, At least one thin film seal portion configured to isolate the isolation environment from the environment external to the isolation environment in combination with the stator poles, wherein the load of the pressure differential between the isolation environment and the environment external to the isolation environment is shared by both the at least one thin film seal portion and the stator poles, at least one thin film seal portion Including A transport device in which each of the plurality of laminated rotor poles of the laminated rotor poles interacts with the stator poles to form a closed magnetic flux circuit between the laminated rotor poles of the at least one vacuum-compatible laminated rotor and the stator poles of the at least one stator that interacts with the laminated rotor poles.

15. The transport device according to claim 14, wherein the drive unit includes at least one drive shaft and a holding member configured to attach the at least one vacuum-compatible laminated rotor to the at least one drive shaft and clamp the set of the alternately stacked laminates together.

16. The conveying device according to claim 15, wherein the laminates stacked one on top of the other in the interaction are adhered together.

17. The conveying device according to claim 14, wherein the at least one thin film seal portion is integral with the at least one stator.

18. The conveying device according to claim 14, wherein the at least one thin film seal portion comprises a film attached to the at least one stator.

19. The conveying device according to claim 14, wherein the at least one thin film seal portion is structurally coupled to the at least one stator such that the at least one stator supports the at least one thin film seal portion.

20. The conveying device according to claim 14, wherein the at least one stator structurally supports the at least one thin film seal portion.

21. The conveying device according to claim 14, wherein the shape of the at least one thin film seal portion is at least partially in the shape of a part of the at least one stator extending through the at least one partition wall such that the at least one thin film seal portion is supported by the at least one stator at all locations where the at least one thin film seal portion contacts the isolation environment.

22. The at least one stator includes a stator core, an upper plate, and a bottom plate, wherein the upper plate and the bottom plate form stator poles, are connected to the stator core, are spaced apart by the stator core, and are configured to interact with the at least one vacuum-compatible laminated rotor, The conveying device according to claim 14, wherein the at least one thin film seal portion is between the upper plate and the bottom plate and is configured to isolate the stator core from an isolation environment in which the at least one conveying arm operates.

23. The drive unit further includes a plurality of stator pole extensions disposed within the isolation environment and aligned with respective stator poles, and the at least one thin film seal portion is disposed between each stator pole and a respective stator pole extension.

24. The driving unit further includes a seal support member having an inner surface facing the isolation environment and an outer surface facing the side opposite to the isolation environment, the at least one thin film seal portion being disposed on or adjacent to the inner surface, the seal support member being configured to structurally support the at least one thin film seal portion, and the thin film seal portion structurally supported by the inner surface forming the isolation wall. The conveying device according to claim 23.

25. The conveying device according to claim 24, wherein the seal support member is configured to accommodate the stator pole extension portion.

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