Integrated drive for an energy recovery wheel

Abstract

An energy recovery wheel includes a wheel that rotates on a rotational axis and a drive configured to power rotation of the wheel. The wheel is configured to rotate through at least two different fluid flows and is configured to provide energy transfer (thermal and / or moisture) between the fluid flows. An integrated drive cause rotation of the wheel through the two fluid flows. The integrated drive is supported on a stationary shaft and causes rotation of the wheel about the shaft.

Description

[0001] INTEGRATED DRIVE FOR AN ENERGY RECOVERY WHEEL

[0002] CROSS-REFERENCE TO RELATED APPLICATION(S)

[0003] This application claims the benefit of U.S. Provisional Application No. 63 / 673,539 filed July 19, 2024 and entitled “ENERGY RECOVERY WHEEL HAVING INTEGRATED DRIVE,” and claims the benefit of U.S. Provisional Application No. 63 / 763,641 filed February 26, 2025 and entitled “INTEGRATED DRIVE FOR AN ENERGY RECOVERY WHEEL,” the disclosures of which are hereby incorporated by reference in their entireties.

[0004] BACKGROUND

[0005] The present disclosure relates energy recovery wheels. More specifically, the present disclosure relates to drives for energy recovery wheels.

[0006] Energy recovery wheels are configured to rotate through two fluid streams (e.g., air streams) to provide energy (e.g., thermal and / or moisture) exchange between the fluid streams. Energy recovery wheels are driven to rotate through the two fluid streams to provide the energy exchange. Such energy recovery wheels can be configured as thermal wheels, which provide heat exchange, and / or enthalpy wheels, which provide moisture exchange between the two fluid streams. Energy recovery wheels are typically belt driven in which a belt that wraps around the wheel is driven by an external drive to cause rotation of the wheel.

[0007] SUMMARY

[0008] According to an aspect of the disclosure, a drive for a rotational energy recovery device includes a stationary shaft extending along an axis; an electric motor supported by the shaft; and a housing within which the electric motor is disposed, the electric motor rotatably mounted on the shaft. The electric motor is dynamically connected to the housing such that a rotational output of the electric motor causes rotation of the housing relative to the shaft.

[0009] According to an additional or alternative aspect of the disclosure, a drive for integration into an energy recovery wheel includes a shaft which extends through the energy recover wheel; an electric motor; and at least one gear set. The electric motor and the at least one gear set are located radially between the shaft and the energy recover wheel.

[0010] According to another additional or alternative aspect of the disclosure, a drive for a rotational energy recovery device includes a shaft extending along an axis; an electric motor supported by the shaft; a housing within which the electric motor is disposed, the electric motor rotatably mounted on the shaft; and gearing connecting the electric motor and the housing, the gearing configured to receive a rotational input from the electric motor and provide a rotational output to the housing to cause rotation of the housing about the shaft.

[0011] According to yet another additional or alternative aspect of the disclosure, a method of driving rotation of an energy recovery assembly includes generating a rotational output by an electric motor disposed within a housing, the electric motor mounted on a stationary shaft and the housing rotatably supported on the shaft; and driving rotation of the housing by the rotational output of the electric motor to cause rotation of the housing about the shaft and thereby cause rotation of a wheel mounted to the housing within a first fluid flow in a first pathway and within a second fluid flow in a second pathway, the first pathway fluidly separated from the second pathway by a divider.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a block diagram of an energy recovery system.

[0014] FIG. 2 is a cross-sectional view of an energy recovery assembly.

[0015] FIG. 3A is cross-sectional view of an integrated drive of an energy recovery assembly.

[0016] FIG. 3B is an isometric cross-sectional view similar to that of FIG. 3 A.

[0017] FIG. 3C is an isometric cross-sectional view similar to that of FIG. 3C but showing a connector rotated relative to the shaft.

[0018] FIG. 4 is an exploded view of the hub and drive of the energy recovery assembly.

[0019] FIG. 5 is a cross-sectional view showing an integrated drive of an energy recovery assembly.

[0020] FIG. 6 is a cross-sectional view showing an integrated drive of an energy recovery system with an integrated controller.

[0021] FIG. 7 is a cross-sectional view showing an integrated drive of an energy recovery assembly.

[0022] FIG. 8 is a cross-sectional view showing an integrated drive of an energy recovery assembly.

[0023] FIG. 9 is a schematic diagram of an integrated drive of an energy recovery assembly. DETAILED DESCRIPTION

[0024] This disclosure concerns an energy recovery wheel having an integrated drive. While various examples of energy recovery wheels having integrated drives are shown, it will be understood that aspects demonstrated herein can be applied to a variety of energy recovery wheels in which the features shown herein can be selectively included as well as mixed and matched.

[0025] While the above-identified figures set forth embodiments of the present invention, other embodiments are also contemplated, as noted in the discussion. In all cases, this disclosure presents the invention by way of representation of possibilities and not limitation. It should be understood that numerous other modifications and embodiments can be devised by those skilled in the art, which fall within the scope and spirit of the principles of the invention. The figures may not be drawn to scale, and applications and embodiments of the present invention may include features, steps and / or components not specifically shown in the drawings.

[0026] The present disclosure makes use of multiple embodiments to demonstrate various inventive aspects. The embodiments use similar reference numbers and / or descriptions of the components and aspects. An aspect (material, dimensions, functions, relationship to other aspects, etc.) of a component shown and / or described in connection with one embodiment can be present in a similar component of another embodiment even if not explicitly shown or described for another embodiment, particularly but not exclusively for components of similar reference numbers. For the sake of brevity, such common aspects may not be repeated for each embodiment, but may nevertheless be applicable between embodiments.

[0027] This disclosure uses multiple examples to demonstrate various inventive aspects. The inventive scope of this disclosure is not necessarily limited to any one of these embodiments, nor to all of them in just the manner shown and / or described. Rather, the inventive aspects demonstrated herein can be implemented in various other containers. One aspect or feature shown or described from one embodiment could be implemented on another embodiment in this disclosure even if not shown or described for that embodiment, or various embodiments not illustrated herein. The embodiments illustrated and / or discussed are intended to be illustrative and not limiting, and the described and / or illustrated features can be mixed and matched between different embodiments but including and excluding various features amongst the embodiments. Energy recovery assemblies according to aspects of the disclosure include a drive that is integrated into an energy recovery wheel to drive rotation of the energy recovery wheel. The integrated drive includes a housing within which the rotational generator of the integrated drive is disposed. The wheel can be mounted on the housing such that rotation of the housing causes rotation of the wheel. The housing can be considered to form a hub on which a wheel of the energy recovery assembly is mounted. The integrated drive is configured to rotate on an axis to cause rotation of the wheel. The rotational generator of the integrated drive can be formed as an electric motor, among other options. The rotational generator of the drive can be disposed coaxially with the wheel in various examples, such that a rotor of the integrated drive and the wheel rotate coaxially on a common axis.

[0028] Integrated drives according to various aspects of the present disclosure include reduction gearing that reduces the speed of the rotational output from the motor. The reduction gearing is configured such that the wheel of the energy recovery assembly rotates at a slower rate than the rotor of the integrated drive.

[0029] Several of the figures of the disclosure show a common axis, which is sometimes referred to as a rotational axis. An axis of rotation of the rotor of the motor can be disposed coaxially with the common axis. The term annular is used herein, which can refer to a ring shape (continuous or broken) about the common axis, which can be coaxial with the common axis. The term radial is used herein which when referring to a direction is any direction orthogonal to the common axis, unless otherwise noted. The term axial is used herein which when referring to a direction is any direction parallel with the common axis, unless otherwise noted. The terms circumferential or circumferentially as used herein means around the common axis, unless otherwise noted.

[0030] Components can be considered to radially overlap when those components are disposed at common axial locations along an axis. A radial line extending from the axis will extend through each of the radially overlapping components. Components can be considered to axially overlap when those components are disposed at common radial and circumferential locations relative to an axis such that an axial line parallel to the axis extends through the axially overlapping components. Components can be considered to circumferentially overlap when aligned about the axis, such that a circle centered on the axis passes through the circumferentially overlapping components.

[0031] FIG. 1 is a block diagram of energy recovery system 10. Energy recovery system 10 includes energy recovery assembly 12. Energy recovery assembly 12 includes integrated drive 14 and wheel 16. Rotator 18, housing 20, and shaft 22 of integrated drive 14 are shown.

[0032] Energy recovery system 10 is configured to provide energy recovery, such as for ventilation systems, for exhaust gasses of industrial processes, among other options. In the example shown, energy recovery system 10 is configured to provide energy transfer, such as heat or moisture transfer, between two fluid streams (e.g., gas streams) FA1, FA2. The fluid streams FA1, FA2 can be formed as supply and exhaust gasses, among other options. Fluid stream FA1 flows within pathway 24a and fluid stream FA2 flows within pathway 24b. Pathways 24a, 24b can be formed as ducts, among other options. The pathways 24a, 24b are fluidly separated from each other by divider 26.

[0033] Wheel 16 rotates about the shaft 22. The wheel 16 is supported by the shaft 22. Shaft 22 can be configured as a static shaft 22 that does not rotate during rotation of the wheel 16. The shaft 22 is stationary and non-rotating. The shaft 22 can be considered to form an axle for integrated drive 14. Wheel 16 can rotate relative to the shaft 22. The wheel 16 is mounted to integrated drive 14. Integrated drive 14 is configured to power rotation of the wheel 16 on a wheel axis, which can be coaxial with common axis CA.

[0034] Housing 20 is supported by the shaft 22. Housing 20 is rotatable relative to the shaft 22. Wheel 16 is mounted to housing 20. The housing 20 can rotate relative to the shaft 22 to cause rotation of the wheel 16. Housing 20 can be mounted to shaft by one or more bearings that facilitate rotation of the housing 20 relative to the shaft 22.

[0035] Rotator 18 is configured to cause rotation of the housing 20, and thus rotation of the wheel 16, relative to the shaft 22. The rotator 18 can be mounted on the shaft 22. Rotator 18 can include one or more static portions that are mounted to shaft 22 and rotationally fixed to shaft 22. Rotator 18 includes one or more rotating portions that provide a rotational input to housing 20 to cause rotation of housing 20. In various examples, the static portion of the rotator 18 can be mounted to the shaft 22 and a rotating portion of the rotator 18 can be connected to the housing 20 to rotationally drive the housing 20. Rotator 18 can be configured as or include an electric motor, among other options. For example, a stator of the electric motor can be mounted to the shaft 22 and a rotor of the electric motor can provide a rotational output that drive rotation of housing 20.

[0036] Integrated drive 14 is disposed directly radially inward of the wheel 16. Rotator 18 can, in various examples, be disposed directly radially inward of the housing 20. Rotator 18 can, in various examples, be disposed directly radially inward of the wheel 16. Rotator 18 can, in various examples, be disposed coaxially with the rotational axis of the wheel 16.

[0037] In various examples, rotator 18 includes gearing that is configured to provide the rotational input to the housing 20 to cause rotation of the housing 20. The gearing can be connected to a motor, such an electric motor. The gearing can be configured as reduction gearing that reduces the rotational speed between the motor and the housing 20 such that the housing 20 rotates slower than the rotor of the motor. The gearing can be of any configuration suitable for providing speed reduction between the motor and the housing 20. For example, the gearing can be formed as and / or include any one or more a worm gear, a compound planetary gear set, a multi-stage planetary gear set, a harmonic gearset, among other options.

[0038] While the wheel 16 rotates, two different fluid flows FA1 , FA2 pass through the wheel 16. In the example shown, fluid flow FA1 flows from a first side of the wheel 16 to a second side of the wheel 16, while fluid flow FA2 flows from the second side of the wheel 16 to the first side of the wheel 16. The wheel 16 is permeable to such fluid flow. The wheel 16 can contain desiccant, such as silica, or other material which can absorb heat and / or moisture to exchange the heat and / or moisture between the first and the second fluid flows FA1, FA2 as the wheel 16 turns, to recover energy (which can include dissipation) in the form of heat and / or moisture. The wheel 16 can be formed from a material, such as thermally conductive metal, to exchange heat between the first and second fluid flows FA1 , FA2. The divider 26 may be static to separate the first fluid flow FA1 from the second fluid flow FA2 such as to section different areas of the wheel 16 for the first fluid flow FA1 and second fluid flow FA2. It is understood that the fluid flows FA1 , FA2 can be in opposite flow directions relative to each other (as shown) or in a same flow direction. The wheel 16 can rotate relative to the divider 26 and through the pathways 24a, 24b to provide the energy recovery.

[0039] In typical energy recovery wheel systems, the wheel is rotated slowly by a belt drive, with the motor being outside of the wheel. This presents various problems, including additional space and / or ducting to accommodate the exterior motor and belting, amongst other disadvantages.

[0040] Integrated drive 14 provides significant advantages. Integrated drive 14 is disposed directly radially inward of wheel 16 and housing 20 supports wheel 16 on the shaft 22. The rotator 18 is disposed within housing 20 and supported by shaft 22. Integrated drive 14 provides a compact driving configuration for energy recovery assembly 12, eliminating the need for external motors and for belts that can wear over time. The integrated drive 14 thereby frees up space in the operating environment and provides for material savings.

[0041] Integrated drive 14 can be configured such that housing 20 rotates within the pathways 24a, 24b during operation of energy recovery system 10. The housing 20 passing through both the fluid flows FA1, FA2 can provide for cooling of the rotator 18, such as when housing 20 passes through the cooler of the fluid flows FA1, FA2. The housing 20 passing through both fluid flows FA1 , FA2 removes at least a portion of the integrated drive 14 from a heated exhaust stream, in examples in which one of fluid flows FA1, FA2 is a heated exhaust stream.

[0042] FIG. 2 is a simplified cross-sectional view of energy recovery assembly 12. Integrated drive 14 and wheel 16 of energy recovery assembly 12 are shown. Housing 20, rotator 18, and shaft 22 of integrated drive 14 are shown. Motor 28 and gearing 30 of rotator 18 are shown.

[0043] The wheel 16 is mounted on housing 20 that is configured to rotate relative to the non-rotating shaft 22. Shaft 22 is elongate along common axis CA. In the example shown, the shaft 22 projects out of both axial ends of the housing 20 while the wheel 16 is supported on a radial exterior of the housing 20.

[0044] Integrated drive 14 is configured to cause rotation of wheel 16 about the common axis CA. Rotator 18 is configured to cause rotation of housing 20, thereby causing rotation of the wheel 16, on the common axis CA. In the example shown, the rotator 18 is disposed within the housing 20. In the example shown, the shaft 22 extends coaxially through the wheel 16, while at least a portion of the rotator 18 is disposed radially between the shaft 22 and the wheel 16.

[0045] Motor 28 of rotator 18 is connected to shaft 22. A stator of the motor 28 is fixed relative to the shaft 22 to remain stationary with the shaft 22. A rotor of the motor 28 is configured to rotate relative to the stator 32 and provides the rotational output from the motor 28. Gearing 30 is connected to the rotor 34 to receive the rotational output from the motor 28. The gearing 30 is also connected to the housing 20 to drive rotation of the housing 20 about the common axis CA. The gearing 30 can provide speed reduction and torque increase between output provided by motor 28 and the input provided to housing 20.

[0046] Motor 28 and gearing 30 are disposed within housing 20. Motor 28 and gearing 30 can be disposed coaxially within housing 20. Motor 28 and gearing 30 are disposed at least partially around the shaft 22. The rotor of the motor 28 can rotate on the common axis CA such that common axis CA is coaxially with the rotational axis of the rotor 34. The gearing can be configured such that the primary rotational axis of the gearing 30 is disposed coaxial with the common axis CA.

[0047] FIG. 3 A is cross-sectional view of integrated drive 14. FIG. 3B is an isometric cross-sectional view similar to that of FIG. 3A. FIG. 3C is an isometric cross- sectional view similar to that of FIG. 3C but showing connector 60 rotated relative to the shaft 22 from the position shown in FIG. 3B. FIG. 4 is an isometric exploded view of integrated drive 14. FIGS. A-4 are discussed together.

[0048] Motor 28 and gearing 30 of rotator 18 are shown. Support body 50 and end caps 52a, 52b of housing 20 are shown. Electric motor 28 includes stator 32 and rotor 34. Gear sets 36a, 36b of gearing 30 are shown. Gear set 36a includes planet gears 38a and ring gear 40a. Gear set 6b includes planet gears 38b and ring gear 40b. Hub bearings 42 support housing 20 relative to shaft 22. Connector bearings 44a, 44b support connector 60 relative to shaft 22. Planet bearings 46a, 46b support planet gears 38a, 38b.

[0049] Shaft 22 supports other components of integrated drive 14. Housing 20 is rotatably mounted on shaft 22 and is configured to rotate relative to shaft 22. Shaft 22 extends axially outward of housing 20 in both axial directions along the common axis C A. Shaft 22 can interface with and be supported by shaft supports 48. Shaft supports 48 can interface with shaft 22 to prevent rotation of shaft 22 on common axis CA during operation of energy recovery assembly 12. For example, shaft 22 can interface with one or multiple of shaft supports 48 at one or more keyed interfaces. In the example shown, the shaft support 48 is formed as a bracket that captures a portion of the shaft 22.

[0050] Housing 20 is configured to support wheel 16. Housing 20 is supported on shaft 22 by hub bearings 42. In the example shown, hub bearings 42 are configured as angled roller bearings, though it is understood that other configurations are possible. Wheel 16 can extend radially outward from housing 20. In the example shown, wheel 16 is configured to mount on support body 50. End caps 52a, 52b are disposed at opposite axial ends of the support body 50. In the example shown, end caps 52a, 52b are formed separately from support body 50 and connected to support body 50, though it is understood that not all examples are so limited. In the example shown, each end cap 52a, 52b is mounted to support body 50 by cap fasteners 54. Cap fasteners 54 can be formed as threaded fasteners (e.g., bolts) among other options. End caps 52a, 52b interface with hub bearings 42 to mount housing 20 on shaft 22. Rotator 18 is disposed within housing 20. Rotator 18 is fully disposed within housing 20 in the example shown. Rotator 18 includes electric motor 28 that is configured to generate a rotational output to cause rotation of housing 20. The electric motor 28 can include any type of electric motor, including a radial flux, axial flux, or transverse flux type motor, amongst other options.

[0051] Motor 28 includes stator 32 and rotor 34. In the example shown, electric motor 28 is coaxial with the shaft 22. In the example shown, shaft 22 extends fully through the electric motor 28 such that shaft 22 projects in both axial direction ADI and axial direction AD2 outward of motor 28. Stator 32 includes at least one coil 56 that is configured to generate electromagnetic flux that interfaces with flux of the magnets 58 of rotor 34 to cause rotation of rotor 34. The electric motor 28 is an outer rotating motor in this example, in which coils 56 of stator 32 are disposed radially inward of magnets 58 of rotor 34. The stator 32 is configured to remain stationary radially inward while across an air gap from the stator 32 the rotor 34 with magnets 58 is electromagnetically caused to rotate by flux fields generated by the coils 56 of the stator 32.

[0052] Connector 60 is configured to be rotatably driven by motor 28. The rotor 34, electromagnetically acted upon by the stator 32, rotates the connector 60. In the example shown, connector 60 can support one or more of gears and bearings, among other rotating components.

[0053] In various examples, connector 60 can be considered to form a portion of the motor 28, such as a portion of the rotor 34 to which the magnets 58 are connected. In the example shown, connector 60 includes ring body 64 and rotor flange 66. Ring body 64 supports various of the gears of gearing 30. Ring body 64 extends round the shaft 22 and is rotatably mounted to shaft 22. Connector bearings 44a, 44b are disposed between ring body 64 and shaft 22. Connector bearings 44a, 44b support rotation of connector 60 relative to shaft 22.

[0054] Rotor flange 66 projects from the support body 50 and radially overlaps with the stator 32. In the example shown, rotor flange 66 projects axially outward from a axial end of ring body 64. The rotor flange 66 can support the magnets 58 of the rotor 34. As such, the rotor flange 66 can be considered to form a rotor body of the rotor 34 of the electric motor 28. In the example shown, the magnets 58 of rotor 34 are mounted to connector 60 such that connector 60 rotates 1 : 1 with the rotational output of the motor 28.

[0055] Carrier 62 is connected to shaft 22. Carrier 62 is configured to remain stationary during operation. Carrier 62 does not rotate relative to the shaft 22 during operation. Carrier 62 is fixed relative to shaft 22 to prevent rotation of carrier 62 relative to shaft 22. Carrier 62 can, in some examples, be formed monolithically with shaft 22. In various other examples, carrier 62 can be formed separately from shaft 22 and connected to shaft 22, such as by one or more fasteners, such as threaded fasteners. In the example shown, carrier 62 is fixed directly to shaft 22 to rotationally fix carrier 62 relative to shaft 22. In the example shown, carrier 62 is connected to shaft 22 by an array of carrier fasteners 68 that are configured to extend through carrier 62 into a portion of shaft 22 to fix carrier 62 to shaft 22. Carrier fasteners 68 can be formed as threaded fasteners (e.g., bolts) among other options.

[0056] Connector 60 and carrier support gearing 30 that transmits the rotational output from motor 28 to housing 20. Connector 60 is configured to rotate relative to shaft 22 during operation. Connector 60 is configured to rotate relative to both shaft 22 and housing 20. The connector 60 rotates at a different speed from housing 20 as gearing 30 provides speed reduction between the rotational speed output by motor 28 and the rotational speed of the housing 20.

[0057] In the example shown, gearing 30 includes gear set 36a and gear set 36b that transmit rotational motion from motor 28 to housing 20. Gear set 36a receives a rotational input from motor 28 and provides rotational motion to gear set 36b. Gear set 36b receives rotational motion from gear set 36a and provides rotational motion to housing 20 to drive rotation of housing 20.

[0058] Carrier 62 is connected to and supports ring gear 40a. Ring gear 40a is fixed to carrier 62 such that ring gear 40a does not rotate relative to shaft 22 during operation of integrated drive 14. In the example shown, the ring gear 40a is connected to carrier 62 by one or more ring fasteners 70, such as threaded fasteners (e.g., bolts), though it is understood that other connection types are possible. In some examples, ring gear 40a can be formed monolithically with carrier 62. Ring gear 40 is disposed such that the ring teeth 82a are oriented radially inwards towards common axis CA.

[0059] Ring gear 40a is spaced radially inward from housing 20 such that housing 20 can rotate relative to ring gear 40a. A gap is disposed radially between support body 50 and ring gear 40a such that ring gear 40a does not contact support body 50.

[0060] Ring gear 40b is connected to housing 20 and is configured to rotate with housing 20. Ring gear 40b can be connected to housing 20 in any desired manner. In the example shown, gear fasteners 72 connect ring gear 40b to housing 20. The gear fasteners 72 are formed as cap fasteners 54 in the example shown in that the gear fasteners 72 also connect end cap 52a to support body 50. In the example shown, a portion of the exterior of the housing 20 can be formed by ring gear 40b. In the example shown, a portion of the ring gear 40b is captured between end cap 52a and support body 50. The gear fasteners 72 extend through end cap 52a and through ring gear 40b and into support body 50. Gear fasteners 72 can be formed as threaded fasteners (e.g., bolts) among other options. Rotational motion from rotator 18 is transmitted to housing 20 at ring gear 40b.

[0061] In the example shown, connector 60 supports planet gears 38a of gear set 36a and planet gears 38b of gear set 36b. It is understood that while gearing 30 includes three planet gears 38a and three planet gears 38b in the example shown, gearing 30 can include any desired number of planet gears 38a, 38b.

[0062] In the example shown, connector 60 includes gear slots 74 within which the planet gears 38a, 38b are disposed. A planet gear 8a and a planet gear 38b are disposed in a common gear slot 74. In the example shown, each gear slot 74 contains a planet gear 38a and a planet gear 38b, though it is understood that not all examples are so limited. For example, the paired planet gear 38a and planet gear 38b can be disposed in separate gear slots 74 spaced along the connector 60 from each other.

[0063] In the example shown, a planet gear 38a and a planet gear 38b within the same gear slot 74 are connected together for simultaneous rotation. The paired planet gear 38a and planet gear 38b can be rotationally fixed for simultaneous rotation at a common rotational speed. The paired planet gears 38a, 38b can be disposed coaxially on a common gear axis GA. The gear axis GA is disposed radially outward of common axis CA. In the example shown, the paired planet gear 38a and planet gear 38b are formed monolithically as a single component, though it is understood that not all examples are so limited.

[0064] The paired planet gear 38a and planet gear 38b form a gear block 76 that is disposed at least partially within a gear slot 74 of the connector 60. The gear block 76 is a dual-toothed component that includes tooth set 78a (e.g., of planet gear 38a) and includes tooth set 78b (e.g., of planet gear 38b). Inner shaft 80 extends through gear block 76 and is connected to carrier 62. Planet bearings 46a, 46b are disposed between gear shaft 22 and gear block 76 to rotationally support gear block 76 on gear shaft 22.

[0065] In the example shown, gear block 76 is supported by planet bearings 46a, 46b. Planet bearing 46a is disposed directly radially inward of tooth set 78a. Planet bearing 46b is disposed directly radially inward of tooth set 78b. The tooth sets 78a, 78b respectively radially overlap with planet bearings 46a, 46b. In the example shown, planet bearing 46a radially overlaps with the toothed interface 84a between tooth set 78a and ring teeth 82a of ring gear 40a. In the example shown, planet bearing 46b radially overlaps with the toothed interface 84b between tooth set 78b and ring teeth 82b of ring gear 40b. The radial overlap between planet bearings 46a, 46b and the toothed interfaces 84a, 84b balances loading on gear block 76 and assists in maintaining concentricity of planet bearings 46a, 46b on gear axis GA.

[0066] Planet bearings 46a, 46b are positioned relative to connector bearings 44a, 44b to balance loading on connector 60. Planet bearings 46a, 46b are positioned relative to connector bearings 44a, 44b in a manner that maintain concentricity of rotating components on the common axis CA. In the example shown, the planet bearings 46a, 46b that support the gear blocks 76 radially overlap with connector bearings 44a, 44b, which can provide for more direct load transfer radially inwards to the support shaft 22.

[0067] In the example shown, at least a portion of the planet bearings 46a, 46b is disposed axially inward, towards an axial space between the two connector bearings 44a, 44b. The pair of planet bearings 46a, 46b are disposed axially closer to each other than the pair of connector bearings 44a, 44b. The relative positioning of planet bearings 46a, 46b to connector bearings 44a, 44b, both individually and as pairs, provide for force balancing along common axis CA and about shaft 22. Such a configuration assists in maintaining concentricity more direct load transfer radially inwards to the support shaft 22.

[0068] The connector bearings 44a, 44b are additionally or alternatively positioned such that the connector bearings 44a, 44b radially overlap with the toothed interfaces 84a, 84b, respectively. The radial overlap between the connector bearings 44a, 44b and toothed interfaces 84a, 84b provide for more direct load transfer radially inwards to shaft 22 and provides for concentric loading about common axis CA. In the example shown, a radial line R extending radially outward from common axis CA can pass through a connector bearing 44a, 44b then a planet bearing 46a, 46b, and then a toothed interface 84. The radial alignment between the support bearings (e.g., connector bearings 44a, 44b and planet bearings 46a, 46b) and the load generating interfaces (e.g., toothed interface 84a, 84b) provides for a compact configuration of for integrated drive 14 and provides for balanced loading and smooth rotational motion transmission by integrated drive 14.

[0069] The relative alignment of load transmitting components of integrated drive 14 provides significant advantages. The alignment of connector bearings 44a, 44b relative to planet bearings 46a, 46b assists in maintaining concentricity and load transmission. Similarly, the alignment of planet bearings 46a, 46b and / or connector bearings 44a, 44b relative to toothed interfaces 84a, 84b provides for balanced loading and smooth rotational motion transmission.

[0070] Tooth set 78a and tooth set 78b can have different tooth counts relative to each other. The tooth count is the number of teeth on the gear. Tooth set 78b can have a larger tooth count than tooth set 78a. Similarly, ring gear 40a and ring gear 40b can have different tooth counts relative to teach other. Ring gear 40b can have a larger tooth count that ring gear 40a. The varying tooth counts provide for a large gear reduction, such as 500: 1 , 1000: 1 , 5000: 1 , between the rotational speed output by motor 28 and the rotational speed of the housing 20, though it is understood that other ratios are possible.

[0071] In some examples, a first ratio between the tooth count of the ring teeth 82a and the tooth count of tooth set 78a can be greater than a second ratio between the tooth count of ring teeth 82b and tooth set 78b. In some examples, the second ratio can be about 95% or more of the first ratio. In some examples, the second ratio can be about 97% or more of the first ratio.

[0072] In various additional or alternative examples, the pitches of the teeth of gear set 36a varies from the pitches of the teeth of gear set 36b. For example, the pitches of the teeth in gear set 36a (including planet gears 38a and ring gear 40a) can be less than the pitches of the teeth in gear set 36b (including planet gears 38b and ring gear 40b). The difference in pitch can provide for a large gear reduction, such as 500:1, 1000:1, 5000: 1, between the rotational speed output by motor 28 and the rotational speed of the housing 20, though it is understood that other ratios are possible.

[0073] In the example shown, the gearing 30 that provides speed reduction between motor 28 and housing 20 is disposed radially between shaft 22 and support body 50. The gearing 30 is disposed radially outward of the shaft 22 and radially inwards of the support body 50. The gearing 30 is disposed radially outward of the shaft 22 and radially inward of wheel 16 that is supported by housing 20. The gearing 30 can be disposed directly radially inward of wheel 16. In the example shown, the gearing 30 radially overlaps with the housing 20 and with the wheel 16. In the example shown, a radial line extending directly radially outward from the common axis CA can, depending on the rotational position of the connector 60, pass through the shaft 22, then a gear block 76, then the support body 50, and then the wheel 16.

[0074] Motor 28 is disposed radially inward of wheel 16. In the example shown, the motor 28 is disposed radially between the shaft 22 and the support body 50. In the example shown, the motor is disposed directly radially between shaft 22 and support body 50. Motor 28 is disposed radially between the shaft 22 and the wheel 16. In the example shown, the motor 28 is disposed directly radially between the shaft 22 and the wheel 16. The motor 28 can be disposed directly radially inward of wheel 16. In the example shown, the motor 28 radially overlaps with the housing 20 and with the wheel 16. In the example shown, a radial line extending directly radially outward from the common axis CA can pass through the shaft 22, then the motor 28, then the housing 20, and then the wheel 16. In the example shown, a radial line extending directly radially outward from the common axis CA can pass through the shaft 22, then the stator 32, then the rotor 34, then the housing 20, and then the wheel 16.

[0075] In the example shown, the motor 28 is disposed on one axial side of the gearing 30. Motor 28 is spaced in axial direction AD2 from the gearing 30 that transmits the rotational motion to housing 20. Motor 28 does not radially overlap with any of gear blocks 76 in the example shown. The motor 28 does not radially overlap with the rotating ring gear 40b in the example shown. The motor 28 does not radially overlap with the stationary ring gear 40a in the example shown. In the example shown, the motor 28 is not disposed axially between gear set 36a and gear set 36b. Instead, the motor 28 is disposed axially outward of both gear sets 36a, 36b.

[0076] During operation, motor 28 generates a rotational output that drives rotation of connector 60. Electrical signals are provided to the coils 56 of stator 32 to electromagnetically drive rotation of the rotor 34. The connector 60 rotates on the common axis CA and carries the gear blocks 76 about the common axis CA. Planet gears 38a are engaged with ring gear 40b. The engagement between planet gears 38a and ring gear 40a causes the planet gears 38a to rotate on the gear axis GA.

[0077] Planet gears 38a are rotationally fixed to planet gears 38b such that rotation of planet gears 38a causes rotation of planet gears 38b. The planet gears 38a and planet gears 38b of a gear block 76 rotate at the same rotational speed on their gear axis GA. Planet gears 38b are engaged with ring gear 40b, which is rotationally fixed to housing 20. Rotation of the planet gears 38b on their gear axis GA and also about the common axis CA drives rotation of ring gear 40b about the common axis CA. The ring gear 40b is rotationally fixed to housing 20 such that rotation of ring gear 40b causes rotation of housing 20, and thus of wheel 16, about the common axis CA. The integrated drive 14 thereby causes rotation of the wheel 16 through both pathways 24a, 24b to facilitate energy exchange between the fluid streams FA1, FA2. The integrated drive 14 of energy recovery assembly 12 provides significant advantages. The rotator 18 being disposed within the housing 20 of the energy recovery assembly 12 provides for a compact driving configuration of the energy recovery assembly 12. Rotator 18 is disposed within the housing 20 and mounted on the shaft 22 that supports the rotating components of the energy recovery assembly 12. The integrated drive 14 eliminates belts and other wear components from energy recovery assembly 12. Integrated drive 14 provides a large speed reduction between the rotational output from motor 28 and the rotational speed of wheel 16. The speed reduction facilitates driving rotation of the wheel 16 at a relatively slow speed (e.g., 5 revolutions per minute (rpm), 3 rpm, Irpm, 0.5 rpm, 0.25 rpm, or fewer).

[0078] Integrated drive 14 provides for a high reduction ratio (e.g., greater than 1000: 1 , among other options) in a compact configuration. In the example shown, integrated drive 14 includes two ring gears 40a, 40b and a single connector 60. The single connector 60 carries the planet gears 38a, 38b. The integrated drive 14 provides a high reduction ratio in a compact package that facilitates slow rotation of the wheel 16 for efficient energy (e.g., thermal energy and / or moisture) recovery.

[0079] The concentricity and smooth load transmission provided by integrated drive provides improved efficiency for energy transmission system 10. For example, the outer radial edge of wheel 16 can be closer to the walls defining pathway 24a and / or pathway 24b. Such a configuration allows the wheel 16 to be allows for smaller and / or less complex sealing of a radial gap between the wheel 16 and wall, and provides for higher efficiency as a greater portion of the fluid flows through, rather than around, the wheel 16.

[0080] Integrated drive 14 is disposed within housing 20 and powers rotation of housing 20. The integrated drive 14 being within the housing 20 provides for compact configuration of housing 20 and integrated drive 14. Such a configuration allows for mounting and operation in tight spaces where external driving (e.g., by a belt) is impractical or otherwise complicated.

[0081] FIG. 5 is an isometric cross-sectional view of integrated drive 114 including rotator 118 and housing 120. Integrated drive 114 is substantially similar to integrated drive 14 (FIGS. 3A-4) and components of integrated drive 114 that are the same as or substantively similar to components of integrated drive 14 are indicated with the same reference number except increased by “100” (e.g., integrated drive 14 and integrated drive Rotator 118 can be contained within a housing 120. The weight of the wheel 16 may be supported on the housing 120. The rest of integrated drive 114 is contained within the housing 120. Shaft 122 extends through the housing 120. Shaft 122 extends fully axially through the housing 120. Shaft 122 projects out of housing 120 in both axial directions ADI and AD2 along the common axis CA. The shaft 122 is kept static while the housing 120 rotates around the shaft 122, which rotation of the housing 120 rotates the wheel 16. Housing 120 is supported on the shaft 122 by hub bearings 142 that allow rotation of the housing 120 relative to the shaft 122.

[0082] Carrier 162 is mounted on shaft 122. Carrier 162 is rotationally fixed relative to shaft 122 such that carrier 162 remains static during rotation of housing 120 and wheel 16. In the example shown, the carrier 162 is formed monolithically with shaft 122, though it is understood that not all examples are so limited. In some examples, carrier 162 can be formed integrally, though not necessarily monolithically, with shaft 122, such as by being permanently connected to shaft 122 by welding among other options. In various examples, carrier 162 can be connected to shaft by fasteners (e.g., threaded fasteners such as bolts), among other options. Carrier 162 can support gears, bearings, and a motor, as further shown and discussed herein.

[0083] Integrated drive 114 includes electric motor 128. The electric motor 128 can include any type of electric motor, including a radial flux, axial flux, or transverse flux type motor, amongst other options. Motor 128 is mounted on shaft 122 and supported by shaft 122. Motor 128 includes stator 132 and rotor 134 that is configured to rotate relative to stator 132. In the example shown, electric motor 128 is disposed coaxial with the shaft 122 on common axis CA. As such, the axis of the shaft 122 and the rotational axis of the rotor 134 are disposed coaxially. Shaft 122 extends fully axially through the electric motor 128 in the example shown.

[0084] In the example shown, electric motor 128 is an outer rotating motor in which coils 156 of stator 132 remain stationary and are disposed radially inward across an air gap from rotor 134 that rotates relative to the stator 132. The rotor 134 includes magnets 158 that are electromagnetically caused to rotate by flux fields generated by the coils 156 of the stator 132. Gearing 130 is configured to transmit rotational motion from motor 128 to the housing 120 to cause rotation of the housing 120 relative to the shaft 122.

[0085] The rotor 134, electromagnetically acted upon by the stator 132, rotates the connector 160. In the example shown, the connector 160 can be considered to from a body of the rotor 134. The magnets 158 of rotor 134 are mounted on connector 160 in the example shown. Connector 160 includes ring body 164 and bearing mounts 186. In the example shown, the ring body 164 is disposed axially between the bearing mounts 186. Ring body 164 can be considered to form the rotor body of the rotor 134. The magnets 158 of rotor 134 are mounted on an inner radial side of the ring body 164 in the example shown. Ring body 164 can extend fully circumferentially around shaft 122 and common axis CA.

[0086] Bearing mounts 186 interface with planet bearings 146a, 146b. In the example shown, a first bearing mount 186 is extends from a first axial side of the ring body 64 and a second bearing mount 186 extends from a second axial side of the ring body 164. As such, the ring body 164 is disposed axially between bearing mounts 186 of the connector 160 in this example.

[0087] In the example show, each bearing mount 186 is formed as a cup. The cup receives a planet bearing 146a, 146b that supports rotation of the various planet gears 138a, 138b of integrated drive 114. In the example shown, an array of bearing mounts 186 is formed on a first axial side of the connector 160 and another array of bearing mounts 186 is formed on a second axial side of the connector 160. The sets of bearing mounts 186 are arrayed about the shaft 122 and the common axis CA.

[0088] The connector 160 is supported in part by gear sets 136a, 136b. Each of the gear set 136a and gear set 136b can be planetary gear sets, though it is understood that other options are possible. Rotation of the rotor 134 of the electric motor 128 rotates the connector 160 and moves both of gear set 136a and gear set 136b to rotate the housing 120 relative to the shaft 122. Gear set 136a includes an array of planet gears 138a that are disposed about the common axis CA. Gear set 136b includes an array of planet gears 138b that are disposed about the common axis CA. In the example shown, each planet gear 138a is disposed coaxially with a planet gears 138b on a gear axis GA, which gear axis GA is disposed radially outward of the common axis CA and radially inward of wheel 16.

[0089] An inner shaft 180 connects the coaxial ones of the planet gears 138a and planet gears 138b. The coaxial planet gear 138a, planet gear 138b, and inner shaft 180 can be considered to form a gear block 176. In the example shown, an array of gear blocks 176 are disposed circumferentially around the common axis CA.

[0090] The gear blocks 176 extend between and interface with the ring gears 140a, 140b of the gear sets 136a, 136b. The inner shafts 180 can be considered to connect gear set 136a to gear set 136b, including by transferring rotational motion between the gear sets 136a, 136b. Planet bearings 146a, 146b support the connector 160 and the structure that holds the gear sets 136a, 136b while permitting relative rotation. Motor 128 and gear sets 136a, 136b are located directly radially between shaft 122 and support body 150. In the example shown, the motor 128 is disposed axially between gear set 136a and gear set 136b. The motor 128 can axially overlap with gearing of both gear sets 136a, 136b. The motor 128 can be considered to be axially bracketed by the gear sets 136a, 136b in the example shown. In the example shown, motor 128 is disposed axially between but does not radially overlap with either of ring gear 140a or ring gear 140b.

[0091] Electric motor 128 and the gear sets 136a, 136b are located directly radially between the shaft 122 and support body 150. The motor 128 and gear sets 136a, 136b cause the housing 120 to rotate relative to the shaft 122, thereby turning the wheel 16.

[0092] It is noted that there is a slight difference in pitch of the teeth between gear set 136a and gear set 136b which creates a large gear reduction, such as approximately 5000:1, although other ratios are possible. It is intended that the wheel 16 rotate very slowly. While a two-stage gear reduction is shown, various other embodiments may have a single gear stage. Additionally or alternatively, the tooth counts for the teeth of gear set 136a can vary from the tooth counts of the teeth of gear set 136b, as discussed above with regard to integrated drive 14.

[0093] During operation, electric signals are provided to stator 132 of motor 128. The stator 132 generates magnetic flux fields that interact with the magnetic flux from magnets 158 of the rotor 134. The resulting flux shear causes rotor 134 to rotate relative to the stator 132 and about the shaft 122. In the example shown, the magnets 158 are mounted on ring body 164. The ring body 164 rotates about the shaft 122 on the common axis CA. The connector 160 can be considered to rotate 1 : 1 with the rotational speed output by the motor 128. Planet gears 138a interface with ring gear 140a and the toothed interface 184a between planet gears 138a and ring gear 140a causes rotation of the gear blocks 176.

[0094] Rotation of planet gears 138a causes rotation of the planet gears 138b as the planet gears 138a and planet gears 138b are rotationally fixed together. The planet gears 138a can rotate at the same rotational speed as the planet gears 138b. The toothed interface 184b between planet gears 138b and ring gear 140b drives rotation of ring gear 140b. Ring gear 140b is rotationally fixed to housing 120 such that rotation of ring gear 140b about the common axis CA causes rotation of housing 120 about the common axis CA. The difference in tooth pitch and / or tooth count between gear set 136a and gear set 136b creates the large gear reduction such that housing 120, and thus wheel 16, are caused to rotate at the desired slow rotational speed. FIG. 6 is a cross-sectional view of integrated drive 114 including rotator 118 and housing 120. Integrated drive 114 is the same as integrated drive 114 shown in FIG. 5 but further includes control circuitry 188 within integrated drive 114. Shaft 122 includes wire passage 190 that is formed within shaft 122. Wire passage 190 can be open radially through shaft 122 to provide an opening for wiring 192 to exit from within shaft 122 and into housing 120 and / or to enter into shaft 122 from within housing 120. Wiring 192 extends through the shaft 122 to the module containing the control circuitry 188. The control circuitry 188 can include electrical components necessary to operate the electric motor 128, such as delivering a plurality of electrical signals to the coils 156 of the stator 132. It is understood that control circuitry 188 and wiring 192 can be integrated with any one of the integrated drives shown and / or discussed.

[0095] FIG. 7 is a cross-sectional view of an integrated drive 1 14 for an energy recovery assembly 12. Integrated drive 114 includes lubricant reservoir 194 disposed within housing 120. The housing 120 can be considered to define the lubricant reservoir 194. While integrated drive 114 is shown in FIG. 9, it is understood that the lubricant reservoir 194 can be applied to any one of integrated drives shown and / or discussed herein.

[0096] Lubricant reservoir 194 is formed by housing 120 in the example shown. Lubricant fill path 196 is configured to provide lubricant (e.g., oil, grease, etc.) to lubricant reservoir 194. In the example show, the lubricant fill path 196 is formed within shaft 122, though it is understood that other configuration are possible.

[0097] Lubricant reservoir 194 is configured to hold a supply of lubricant for lubricating the gear interfaces of integrated drive 114. In the example shown, the lubricant reservoir 194 is configured such that the at least a portion of each planet gear 138a, 138b is disposed at least partially within the lubricant during a portion of the rotation of the planet gears 138a, 138b about the common axis CA. At least a portion of each ring gear 140a, 140b can be submerged within the lubricant. The lubricant can fill to the lubricant level LL.

[0098] During operation, the planet gears 138a, 138b can move through the lubricant within lubricant reservoir 194 and carry the lubricant about the common axis CA to provide lubrication throughout the annular movement of the planet gears 138a, 138b about the common axis CA. Such a configuration can provide for full lubrication of the ring gears 140a, 140b.

[0099] FIG. 8 is a cross-sectional view of integrated drive 214. Integrated drive 214 is substantially similar to integrated drive 14 (best seen in FIGS. 3A-4) and components of integrated drive 214 that are the same as or substantively similar to components of integrated drive 14 are indicated with the same reference number except increased by “200” (e.g., integrated drive 14 and integrated drive 214). Integrated drive 214 is substantially similar to integrated drive 114 (FIGS. 5-7) and components of integrated drive 214 that are the same as or substantively similar to components of integrated drive 114 are indicated with the same reference number except increased by “100” (e.g., integrated drive 114 and integrated drive 214).

[0100] Rotator 218 is contained within housing 220. The weight of the wheel 16 may be supported on the housing 220. The rest of integrated drive 214 is contained within housing 220. Shaft 222 extends through housing 220 and projects axially outward of housing 220 in both axial directions ADI, AD2. The shaft 222 is kept static while the housing 220 rotates around the shaft 222, which rotation of the housing 220 rotates the wheel 16. Housing 220 is supported on the shaft 222 by hub bearings 242 that allow rotation of the housing 220 relative to the shaft 222.

[0101] Carrier 262 is mounted on shaft 222. Carrier 262 is rotationally fixed relative to shaft 222 such that carrier 262 remains static during rotation of housing 220 and wheel 16. In the example shown, the carrier 262 is formed monolithically with shaft 222, though it is understood that not all examples are so limited. In some examples, carrier 262 can be formed integrally, though not necessarily monolithically, with shaft 222, such as by being permanently connected to shaft 222 by welding among other options. In various examples, carrier 262 can be connected to shaft by fasteners (e.g., threaded fasteners such as bolts), among other options. Carrier 262 can support gears, bearings, and a motor, as further shown and discussed herein.

[0102] Integrated drive 214 includes electric motor 228. The electric motor 228 can include any type of electric motor, including a radial flux, axial flux, or transverse flux type motor, amongst other options. Motor 228 is supported by shaft 222. Motor 228 includes stator 232 and rotor 234 that is configured to rotate relative to stator 232. In the example shown, electric motor 228 is disposed coaxial with the shaft 222 on common axis CA. As such, the axis of the shaft 222 and the rotational axis of the rotor 234 are disposed coaxially. Shaft 222 extends fully axially through the electric motor 228 in the example shown.

[0103] In the example shown, electric motor 228 is an inner rotating motor in which coils 256 of stator 232 remain stationary and are disposed radially outward across an air gap from rotor 234 that rotates relative to the stator 232. The rotor 234 includes magnets 258 that are electromagnetically caused to rotate by flux fields generated by the coils 256 of the stator 232. In the example shown, electric motor 228 is supported by, and held within, the carrier 262. Shaft 222 extends through electric motor 228.

[0104] Gearing 230 is configured to transmit rotational motion from motor 228 to housing 220 to provide the rotational motion to housing 220. In the example shown, rotor 234 of the electric motor 228 can convey rotational motion to other components of gearing 230 via the hollow shaft sun gear 298.

[0105] In the example shown, sun gear 298 includes gear shaft 300 and gear head 302. The gear teeth 304 of the sun gear 298 are formed on the gear head 302. Gear shaft 300 supports the magnets 258 of the rotor 234 such that the gear shaft 300 can be considered to form a body of the rotor 234, in this example. The magnets 258 are disposed on an outer radial side of the sun gear 298. Sun gear 298 is configured to rotate on the common axis CA. Shaft 222 extends fully axially through sun gear 298 in the example shown. In various examples, one or more bearings can be disposed between sun gear 298 and shaft 222 to support rotation of sun gear 298 relative to shaft 222.

[0106] The rotor 234, electromagnetically acted upon by the stator 232, rotates the sun gear 298. The teeth of sun gear 298 interface with planet gears 238a of gear set 236a. Rotation of the sun gear 298 drives rotation of the planet gears 238a.

[0107] Connector 260 is supported by planet bearings 246. Connector 260 includes ring body 264 and bearing mounts 286. In the example shown, the bearing mounts 286 project radially outward from ring body 264. The bearing mounts 286 can be considered to form ears that are formed as conduits for passage of the inner shaft 280 through the bearing mount 286. The ring body 264 is disposed directly radially inward of the bearing mounts 286 in the example shown. Ring body 264 can extend fully circumferentially around shaft 222 and common axis CA.

[0108] Bearing mounts 286 interface with planet bearings 246. In the example shown, a single bearing mount 286 is associated with each gear block 276 of the integrated drive 214.

[0109] The connector 260 is supported in part by gear sets 236a, 236b. Each of the gear set 236a and gear set 236b can be planetary gear sets, though it is understood that other options are possible. Rotation of the rotor 234 of the electric motor 228 rotates the sun gear 298, which causes rotation of the planet gears 238a on their gear axes GA and causes rotation of the array of planet gears 238a about the common axis CA. Planet gears 238a are rotationally fixed with planet gears 238b such that planet gears 238b rotate with planet gears 238a both on their individual gear axes GA and about the common axis CA. Connector 260 rotates about the common axis CA with the planet gears 238a, 238b. In the example shown, connector 260 is rotatably supported on shaft 222 by connector bearing 244. The connector bearing 244 is disposed radially between the shaft 222 and connector 260.

[0110] Gear set 236a includes an array of planet gears 238a that are disposed about the common axis CA. Gear set 236b includes an array of planet gears 238b that are disposed about the common axis CA. In the example shown, each planet gear 238a is disposed coaxially with a planet gears 238b on a gear axis GA, which gear axis GA is disposed radially outward of the common axis CA and radially inward of wheel 16.

[0111] An inner shaft 280 connects the coaxial ones of the planet gears 238a and planet gears 238b. The inner shaft 280 of each gear block 276 extends through a bearing mount 286 of the connector 260. The planet bearings 246 are disposed radially between the inner shaft 280 and the bearing mount 286 and support rotation of the inner shaft 280 relative to the connector 260.

[0112] The gear blocks 276 extend between and interface with the ring gears 240a, 240b of the gear sets 236a, 236b. The inner shafts 280 can be considered to connect gear set 236a to gear set 236b, including by transferring rotational motion between the gear sets 236a, 236b.

[0113] Motor 228 and gear sets 236a, 236b are located directly radially between shaft 222 and support body 250. In the example shown, the electric motor 228 is not positioned axially between gear set 236a and gear set 236b. Instead, gear set 236a is located axially between the electric motor 228 and gear set 236b. The motor 228 can axially overlap with gearing of both gear sets 236a, 236b.

[0114] Electric motor 228 and the gear sets 236a, 236b are located directly radially between the shaft 222 and housing 220. The motor 228 and gear sets 236a, 236b cause the housing 220 to rotate relative to the shaft 222, thereby turning the wheel 16.

[0115] It is noted that there is a slight difference in pitch of the teeth between gear set 236a and gear set 236b which creates a large gear reduction, such as approximately 5000:1, although other ratios are possible. It is intended that the wheel 16 rotate very slowly. While a two-stage gear reduction is shown, various other embodiments may have a single gear stage. Additionally or alternatively, the tooth counts for the teeth of gear set 236a can vary from the tooth counts of the teeth of gear set 236b, as discussed above with regard to integrated drive 14. During operation, electric signals are provided to stator 232 of motor 228. The stator 232 generates magnetic flux fields that interact with the magnets 258 of the rotor 234. The resulting flux shear causes rotor 234 to rotate relative to the stator 232 and about the shaft 222. In the example shown, the magnets 258 are mounted on gear shaft 300. The sun gear 298 rotates about the shaft 222 on the common axis CA. The sun gear 298 interfaces with planet gears 238a such that rotation of the sun gear 298 causes rotation of the planet gears 238a. Planet gears 238a interface with ring gear 240a at toothed interface 284a such that rotation of the planet gears 238a drives rotation of the assembly of planet gears 238a, and thus rotation of connector 260, about the common axis CA. The connector 260 is driven to rotate about the common axis CA.

[0116] Rotation of planet gears 238a causes rotation of the planet gears 238b as the planet gears 238a and planet gears 238b are rotationally fixed together. The toothed interface 284b between planet gears 238b and ring gear 240b drives rotation of ring gear 240b. Ring gear 240b is rotationally fixed to housing 220 such that rotation of ring gear 240b about common axis CA causes rotation of housing 220 about the common axis CA. The difference in tooth pitch and / or tooth count between gear set 236a and gear set 236b creates the large gear reduction such that housing 220, and thus wheel 16, are caused to rotate at the desired slow rotational speed.

[0117] FIG. 9 is a schematic diagram of integrated drive 314. Integrated drive 314 is substantially similar to integrated drive 14 (FIGS. 3A-4) and components of integrated drive 314 that are the same as or substantively similar to components of integrated drive 14 are indicated with the same reference number except increased by “300” (e.g., integrated drive 14 and integrated drive 314). Integrated drive 314 is substantially similar to integrated drive 113 (FIGS. 5-7) and components of integrated drive 314 that are the same as or substantively similar to components of integrated drive 114 are indicated with the same reference number except increased by “200” (e.g., integrated drive 1 14 and integrated drive 314). Integrated drive 314 is substantially similar to integrated drive 214 (FIG. 7) and components of integrated drive 314 that are the same as or substantively similar to components of integrated drive 214 are indicated with the same reference number except increased by “100” (e.g., integrated drive 214 and integrated drive 314).

[0118] Integrated drive 314 includes motor 328 mounted on shaft 322, housing 320 configured to rotate about shaft 322, and gearing 330. In the example shown, gearing 330 is formed as a multi-stage planetary gearset. In the example shown, gearing 330 includes gear sets 336a-336d. Gear sets 336a-336d are disposed coaxial with electric motor 328 in the example shown. Electric motor 328 is connected to gear set 336a to provide rotational motion from electric motor 328 to gear set 336a. Gear set 336a is configured to provide rotational motion to gear set 336b. Gear set 336b is configured to provide rotational motion to gear set 336c. Gear set 336c is configured to provide rotational motion to gear set 336d. Gear set 336d is connected to housing 320 to drive rotation of housing 320 about the shaft 322 and the common axis CA.

[0119] It is understood that any aspect discussed herein with regard to a particular example may be mixed as between the different examples and features. While the invention has been described with reference to an exemplary embodiment(s), it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment(s) disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. CLAIMS:

1. A drive for a rotational energy recovery device, the drive comprising: a shaft extending along an axis; an electric motor supported by the shaft; a housing within which the electric motor is disposed, the housing rotatably mounted on the shaft; wherein the electric motor is dynamically connected to the housing such that a rotational output of the electric motor causes rotation of the housing relative to the shaft.

2. The drive of claim 2, wherein the electric motor is disposed directly radially between the shaft and the housing.

3. The drive of claim 1 , further comprising: gearing connected to the electric motor and the housing, the gearing configured to transmit rotational motion from the electric motor to the housing, and the gearing configured to provide speed reduction between a rotational speed of the electric motor and a rotational speed of the housing.

4. The drive of claim 3, wherein the gearing includes at least one of a worm gear, a compound planetary gear set, a multi-stage planetary gear set, and a harmonic gear.

5. The drive of any one of claims 3 and 4 wherein the electric motor and the gearing are disposed coaxially.

6. The drive of claim 3, wherein the gearing includes a first gear set and a second gear set, the first gear set configured to transmit the rotational output from the electric motor to the second gear set.

7. The drive of claim 6, wherein the first gear set includes a first plurality of planetary gears interfacing with a first ring gear, and wherein the second gear set includes a second plurality of planetary gears interfacing with a second ring gear.

8. The drive of claim 7, wherein the first ring gear is statically connected to the shaft, and wherein the second ring gear is fixed to the housing.

9. The drive of any one of claims 7 and 8, further comprising: a carrier projecting radially outward from the shaft and fixed relative to the shaft, wherein the first ring gear is fixed to the carrier, and wherein the first ring gear is spaced radially inward from a support body of the housing.

10. The drive of claim 9, wherein the carrier is monolithic with the shaft.

11. The drive of claim 9, wherein the carrier is connected to the shaft by at least one carrier fastener.

12. The drive of any one of claims 7-11, further comprising: a connector disposed around the shaft and configured to rotate about the shaft, wherein the connector connects the first plurality of planetary gears to the second plurality of planetary gears for simultaneous rotation about the axis.

13. The drive of claim 12, wherein the at least a portion of the connector is disposed directly axially between the first plurality of planetary gears and the second plurality of planetary gears.

14. The drive of any one of claims 12 and 13, wherein a plurality of magnets of a rotor of the electric motor are mounted to the connector.

15. The drive of any one of claims 12-14, wherein the gearing includes a plurality of gear blocks, wherein each gear block of the plurality of gear blocks includes a first planet gear of the first plurality of planetary gears rotatably fixed to a second planet gear of the second plurality of planetary gears.

16. The drive of claim 15, wherein at least one planetary bearing supporting rotation of each gear block of the plurality of gear blocks relative to the carrier.

17. The drive of claim 16, wherein for each gear block of the plurality of gear blocks the at least one planetary bearing is disposed between an inner shaft, the inner shaft extending between and connecting the first planet gear and the second planet gear, and the carrier.

18. The drive of claim 16, wherein for each gear block of the plurality of gear blocks the at least one planetary bearing is disposed between an inner shaft fixed to the carrier and the gear block.

19. The drive of any one of claims 12-15, wherein the carrier includes: a ring body disposed at least partially around the shaft; a plurality of bearing supports connected to the ring body and extending from the ring body; wherein a planet bearing configured to support rotation of the gearing relative to the carrier is disposed within each bearing support of the plurality of bearing supports.

20. The drive of claim 19, wherein the plurality of bearing supports includes a first bearing support interfacing with a first planet bearing and a second bearing support interfacing with a second planet bearing, the first bearing support disposed coaxially with the second bearing support.

21. The drive of claim 20, wherein the first bearing support is formed as a first cup open in a first direction along the axis and the second bearing support is formed as a second cup open in a second direction along the axis.

22. The drive of claim 21 , wherein the first direction is opposite the second direction.

23. The drive of claim 19, wherein each bearing support of the plurality of bearing supports is formed as an ear projecting radially outward from the ring body, wherein an inner shaft connecting the first planet gear and the second planet gear projects through the ear.

24. The drive of any one of claims 15-18, wherein the carrier includes a plurality of gear slots open through a radial exterior of the carrier, and wherein a first gear block of the plurality of gear blocks is mounted in a first gear slot of the plurality of gear slots.

25. The drive of claim 24, wherein the first planet gear and the second planet gear of the first gear block project out of the first gear slot and radially outward of the radial exterior of the carrier.

26. The drive of any one of claims 15-25, wherein the first planet gear is disposed coaxial with the second planet gear on a gear axis.

27. The drive of claim 26, wherein the first planet gear is directly adjacent to the second planet gear.

28. The drive of any one of claims 12-27, wherein at least one carrier bearing rotatably supports the carrier on the shaft.

29. The drive of any one of claims 7-13, wherein the gearing further comprises: a sun gear receiving the rotational output from the electric motor, the sun gear connected to the first plurality of planet bearings to drive rotation of the first plurality of planet bearings.

30. The drive of claim 29, wherein the shaft extends fully axially through the sun gear.

31. The drive of any one of claims 29 and 30, wherein the sun gear includes a gear shaft and a gear head, the gear head including sun gear teeth interfacing with teeth of the first plurality of planet gears, and wherein the gear shaft radially overlaps with at least one coil of a stator of the electric motor.

32. The drive of claim 31, wherein the gear shaft supports a plurality of magnets of a rotor of the electric motor.

33. The drive of any one of claims 29-32, wherein the electric motor is an inner rotating motor.

34. The drive of any one of claims 1-31, wherein the electric motor is an outer rotating motor.

35. The drive of any one of claims 6-13 and 29-33, wherein the first gear set is disposed axially between the electric motor and the second gear set.

36. The drive of any one of claims 6-13, 29-33, and 35, wherein gearing and the electric motor are disposed directly radially between the shaft and a radial exterior of the housing.

37. The drive of claim 3, wherein: the gearing includes a first gear set including a first plurality of planetary gears interfacing with a first ring gear, and the gearing includes a second gear set including a second plurality of planetary gears interfacing with a second ring gear; each planet gear of the first plurality of planet gears includes a first tooth count; the first ring gear includes a second tooth count; each planet gear of the second plurality of planet gears includes a third tooth count greater than the first tooth count; the second ring gear includes a fourth tooth count greater than the second tooth count.

38. The drive of claim 37, wherein a tooth pitch of the first gear set differs from a tooth pitch of the second gear set.

39. The drive of claim 3, wherein: the gearing includes a first gear set including a first plurality of planetary gears interfacing with a first ring gear, and the gearing includes a second gear set including a second plurality of planetary gears interfacing with a second ring gear; anda tooth pitch of the first gear set differs from a tooth pitch of the second gear set.

40. An energy recovery assembly comprising: the drive of any one of claims 1-39; and a wheel supported by and extending radially outward from the housing.

41. An energy recovery system comprising: a first pathway configured to contain a first fluid flow; a second pathway configured to contain a second fluid flow; a divider fluidly separating the first pathway from the second pathway; and the energy recovery assembly of claim 40 disposed such that the wheel extends through the divider such that the wheel is partially disposed in the first pathway and partially disposed in the second pathway, wherein the wheel is configured to provide energy transfer between the first fluid stream and the second fluid stream.

42. The energy recovery system of claim 41, wherein the first fluid flow moves in a first flow direction, the second fluid flow moves in a second flow direction, and the first flow direction is opposite the second flow direction.

43. The energy recovery system of any one of claims 41 and 42, wherein the wheel includes one or more of: a thermally conductive material configured to provide heat transfer between the first fluid stream and the second fluid stream; and a desiccant configured to provide moisture transfer between the first fluid stream and the second fluid stream.

44. A drive for integration into an energy recovery wheel, comprising: a shaft which extends through the energy recover wheel; an electric motor; and at least one gear set, wherein the electric motor and the at least one gear set are located radially between the shaft and the energy recover wheel.

45. The drive of claim 44, wherein the electric motor and the at least one gear set are located radially directly between the shaft and the energy recover wheel.

46. The drive of any one of claims 44 and 45, wherein the electric motor is disposed around the shaft.M . The drive of any one of claims 44-46, wherein the shaft remains stationary during rotation of the energy recover wheel.

48. The drive of any one of claims 44-47, wherein the at least one gear set comprises a first planetary gear set around the shaft.

49. The drive of claim 48, wherein the at least one gear set comprises a second planetary gear set around the shaft.

50. The drive of claim 49, wherein the first planetary gear set has a different tooth pitch than the second planetary gear set.

51. The drive of any one of claims 44-50, further comprising a housing that contains the electric motor and the at least one gear set, the wheel mounted on the housing.

52. The drive of any one of claims 44-51 , wherein the electric motor comprises an inner stator having at least one coil and an outer rotor having at least one magnet.

53. The drive of any one of claims 44-51 , wherein the electric motor comprises an outer stator having at least one coil and an inner rotor having at least one magnet.

54. A drive for a rotational energy recovery device, the drive comprising: a shaft extending along an axis; an electric motor supported by the shaft; a housing within which the electric motor is disposed, the housing rotatably mounted on the shaft; and gearing connecting the electric motor and the housing, the gearing configured to receive a rotational input from the electric motor and provide a rotational output to the housing to cause rotation of the housing about the shaft.

55. The drive of claim 54, wherein the gearing and the electric motor are disposed directly radially between the shaft and the electric motor.

56. The drive of any one of claims 54 and 55, wherein the gearing includes at least one of a worm gear, a compound planetary gear set, a multi-stage planetary gear set, and a harmonic gear.

57. The drive of any one of claims 54 and 55, wherein the gearing includes a first gear set and a second gear set, the first gear set connected to the electric motor to receive the rotational output from the electric motor, and the second gear set connected to the second gear set to be rotatably driven by the first gear set.

58. The drive of claim 57, wherein the electric motor is disposed axially between the first gear set and the second gear set.

59. The drive of claim 57, wherein the first gear set is disposed axially between the electric motor and the second gear set.

60. The drive of any one of claims 57-59, wherein at least a portion of the second gear set is fixed to the housing.

61. The drive of any one of claims 57-60, wherein: the first gear set includes a first planet gear interfacing with a first ring gear; the second gear set includes a second planet gear fixed to the first planet gear, the second planet gear interfacing with a second ring gear; the second ring gear is fixed to the housing.

62. The drive of claim 61 , wherein the first ring gear is fixed relative to the shaft.

63. The drive of any one of claims 61 and 62, wherein the first planet gear is supported by a connector and the second planet gear is supported by the connector, the connector configured to rotate about the axis.

64. The drive of claim 63, wherein the carrier is configured to be rotated by the electric motor, wherein the carrier rotates 1 : 1 with a rotor of the electric motor.

65. The drive of any one of claims 61-64, wherein the first planet gear includes a first tooth count; the first ring gear includes a second tooth count; the second planet gear includes a third tooth count greater than the first tooth count; and the second ring gear includes a fourth tooth count greater than the second tooth count.

66. The drive of any one of claims 61-65, wherein a tooth pitch of the first gear set differs from a tooth pitch of the second gear set.

67. A method of driving rotation of an energy recovery assembly, the method comprising: generating a rotational output by an electric motor disposed within a housing, the electric motor mounted on a stationary shaft and the housing rotatably supported on the shaft; and driving rotation of the housing by the rotational output of the electric motor to cause rotation of the housing about the shaft and thereby cause rotation of a wheel mounted to the housing within a first fluid flow in a first pathway and within a second fluid flow in a secondpathway, the first pathway fluidly separated from the second pathway by a divider.

68. The method of claim 67, further comprising: reducing a speed of the rotational output generated by the electric motor by gearing disposed within the housing.

69. The method of claim 68, further comprising: driving a first gear set by the rotational output from the electric motor; driving rotation of a second gear set by the first gear set; and driving rotation of the housing by the second gear set.

70. The method of claim 69, further comprising: directly driving rotation of a connector by the electric motor such that the connector rotates 1 : 1 with a rotor of the electric motor; carrying, by the connector, a plurality of planet gears of the first gear set about the axis; and carrying, by the connector, a plurality of planet gears of the second gear set about the axis.

71. The method of claim 70, further comprising: driving rotation of a ring gear mounted to the housing by interfacing between the plurality of planet gears of the second gear set and the ring gear to thereby drive rotation of the housing.

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