Power generation components

Abstract

A power generation assembly (300) for powering a transport refrigeration system (TRS) (52) of a vehicle (10) is disclosed, the power generation assembly (300) comprising: a torque converter (402) having an engine-side input (404) and a transmission-side output (406); a power take-off (302) connected to the engine-side input (404) of the torque converter (402), the power take-off (302) having a rotational output; and a permanent magnet generator (304) having a rotor (420) directly coupled to the power take-off (302) for power generation; wherein the power generation assembly (300) is configured to be housed in an engine compartment (210) of the vehicle (10) and is configured to generate at least 8 kW of power when the engine-side input (404) has a rotational speed of 500 rpm.

Description

Technical Field

[0001] The present invention relates to a power generation assembly for powering a transport refrigeration system (TRS) of a vehicle. Background Art

[0002] It is known to equip a vehicle with a transport refrigeration system (TRS) and / or a heating, ventilation, and air conditioning (HVAC) system to transport cargo in a temperature-controlled environment. A TRS is typically used to control environmental conditions (e.g., temperature, humidity, air quality, etc.) within the cargo space of a transport unit (e.g., a truck, a container (e.g., a container on a flatbed, an intermodal container, etc.), a box truck, a semi-trailer, a bus, or other similar transport unit). The TRS can maintain the environmental conditions (various) within the cargo space to maintain the cargo (e.g., produce, frozen foods, pharmaceuticals, etc.). In some embodiments, the transport unit may include an HVAC system to control the climate within the passenger compartment of the vehicle.

[0003] It is known to power a TRS or other accessory system on a vehicle using a power take-off that draws mechanical power from an engine or transmission connected to a prime mover, such as an internal combustion engine (e.g., a diesel engine). The mechanical power is connected to a hydraulic pump within the vehicle's engine compartment that circulates hydraulic fluid from the confines of the engine compartment to the rest of the vehicle or a connected trailer, where a hydraulic motor and generator are mounted to generate electricity for the electric TRS system or other electric system.

[0004] It is also known to use a long drive shaft to transfer mechanical power from the power take-off device out of the vehicle's engine compartment. The other end of the drive shaft can be directly connected to a relatively large diameter generator to provide sufficient power for the TRS, or it can be indirectly connected to a relatively small diameter generator through a gearbox or belt and pulley system.

[0005] However, such arrangements are complex because they involve a large number of components to transport power from the engine compartment to the TRS or other systems (eg, bearings, flexible joints, connectors, and clutches). Summary of the Invention

[0006] According to a first aspect, a power generation assembly for powering a transport refrigeration system (TRS) of a vehicle is disclosed, the power generation assembly comprising:

[0007] a torque converter having an engine-side input device and a transmission-side output device;

[0008] a power take-off connected to the engine-side input of the torque converter, the power take-off having a rotational output;

[0009] a permanent magnet generator having a rotor directly connected to the power take-off for power generation;

[0010] The power generation assembly is configured to be housed in an engine compartment of a vehicle, and the power generation assembly is configured to generate at least 8 kW of power when the engine-side input device has a rotation speed of 500 rpm.

[0011] The term "directly connected" as used in the context of a rotor being directly connected to a power take-off is intended to mean that the rotor is fixedly mounted to the rotational output of the power take-off, with no intervening flexible connection or drive shaft therebetween, nor any multiplier system (such as a pulley and belt system) that affects the transmission ratio between the power take-off and the rotor.

[0012] The power take-off can be connected to the engine-side input of the torque converter via a clutchless connection.

[0013] The power take-off device can provide a transmission ratio of 1:1.1 to 1:1.75 (eg, 1:1.2 to 1:1.5) between the engine-side input device of the torque converter and the rotor of the permanent magnet generator.

[0014] When the transmission ratio is 1:1.5, the power generating assembly may be configured to generate at least 10 kW of power when the engine-side input device has a rotational speed of 500 rpm.

[0015] The torque converter may be mounted within the support housing such that the axis of rotation of the torque converter is fixed relative to the support housing, and

[0016] The power output device and the permanent magnet generator are fixedly mounted to the support housing.

[0017] Where a rotating component is fixedly mounted to another component, fixedly mounted is intended to mean that the respective rotating component is mounted such that its axis of rotation and any fixed component remain in fixed alignment with the other component.

[0018] The support housing may be provided with a damping support for connection to a frame of an engine compartment of the vehicle to allow the support housing to move relative to the frame. The power take-off and the permanent magnet generator may be mounted to the support housing so that, in use, the power take-off and the permanent magnet generator move together with the support housing relative to the frame.

[0019] The transmission can be connected to the transmission-side output of the torque converter, and the transmission can be disposed within a support housing. The support housing can have an elongated extent along the transmission's axis of rotation. The permanent magnet generator can be elongated along a generator axis about which the rotor rotates. The axial extent of the permanent magnet generator relative to the transmission's axis of rotation can overlap with or be within the axial extent of the support housing.

[0020] The power take-off and the permanent magnet generator may be configured such that the generator axis is substantially parallel to the transmission axis and / or the rotation axis of the engine-side input device. The engine-side input device may be a shaft between the engine and the torque converter.

[0021] The generator may comprise bearing means configured to support the rotor, separate from any bearing means of the power take-off.The generator may comprise bearing means at each axial end of the rotor.

[0022] The generator may have a rotor outer diameter D and a length L along the generator axis, wherein a length to outer diameter ratio L / D is at least 2, such as at least 2.5.

[0023] The generator may be a 6-pole generator (3 pole pairs).

[0024] The L / D ratio can be at least 200% (of which is the number of pole pairs), such as at least 300% or 400% of.

[0025] The power generation assembly may include liquid cooling for the generator.

[0026] The generator may include an endshield at an axial end opposite the power take-off. The generator may include a fluid port for connecting a liquid cooling circuit to a cooling channel within the generator, wherein the fluid port is disposed in the endshield; and / or electrical terminals for the stator windings of the generator may be disposed in the endshield.

[0027] The generator may be arranged in a generator housing having a diameter or characteristic lateral dimension of no more than 200 mm (e.g. no more than 175 mm or no more than 150 mm) at an axial position along the generator axis. The characteristic lateral dimension may be the largest dimension of the generator housing in a plane perpendicular to the generator axis.

[0028] The rotor may have a laminated structure comprising a plurality of laminations, each lamination comprising a plurality of slots aligned along the generator axis to define elongated channels in which respective permanent magnets are received.

[0029] The generator may be configured to provide power to a load via the load circuit, the generator having an output voltage as a function of the rotational speed of the rotor.The power generation assembly may further include a controller configured to selectively electrically isolate the generator based on determination of a high voltage state of the power generation assembly.

[0030] The controller may determine the high voltage state of the power generating component based on a rotational parameter indicative of the rotational speed of the rotor or an electrical parameter indicative of voltage, current, or power in the load circuit.

[0031] The high voltage state may correspond to: the rotational speed of the engine-side input device of the torque converter being at or above a threshold engine rotational speed, wherein the threshold rotational speed is at least 2000 rpm, for example, at least 2500 rpm; or the rotational speed of the rotor of the generator being at or above a threshold generator speed, wherein the threshold generator speed is at least 3000 rpm, for example, at least 3500 rpm.

[0032] According to a second aspect, there is provided a vehicle comprising the transport refrigeration system according to the first aspect. The vehicle may comprise an engine compartment, and wherein the power generating assembly is arranged within the engine compartment.

[0033] The damping support described above may extend between the nacelle frame and the support housing. There may be no support extending between the nacelle frame and the power take-off. There may be no support between the nacelle frame and the generator.

[0034] A transport refrigeration system (TRS) may be installed in the vehicle, and the generator is connected to the transport refrigeration system to provide power to the transport refrigeration system.

[0035] Power can be supplied directly from the generator to the transport refrigeration system without any intermediate hydraulic system.

[0036] Those skilled in the art will understand that, except in the case of mutual exclusion, features described with respect to any of the above aspects may be applied to any other aspects after making necessary adjustments. In addition, except in the case of mutual exclusion, any feature described herein may be applied to any aspect and / or combined with any other feature described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention will now be described by way of example with reference to the accompanying drawings, in which:

[0038] Figure 1 is a perspective view of an exemplary tractor;

[0039] Figure 2Schematically shows the plan layout of the equipment supported on the vehicle chassis;

[0040] Figure 3 is a perspective view of an exemplary power generation assembly;

[0041] Figure 4 is a schematic cross-sectional view of an exemplary power generation assembly;

[0042] Figure 5 is a perspective cutaway view of a generator of an exemplary power generation assembly; and

[0043] Figure 6 yes Figure 5 Schematic cross-sectional view of the casing of a generator. DETAILED DESCRIPTION

[0044] The present disclosure generally relates to power generation assemblies for vehicles. Examples described herein are applicable to powering a transportation climate control system, such as a TRS, HVAC system, or any other accessory system.

[0045] The term "transmission" is used herein according to US English convention (where it refers to the gearbox arrangement used to shift between gear ratios) rather than UK English convention (where it refers to the entire drivetrain of a vehicle).

[0046] Figure 1 An exemplary vehicle 10 is shown, particularly a semi-trailer for transporting cargo stored in a cargo compartment (eg, a container, a trailer, etc.) to one or more destinations.

[0047] The exemplary vehicle 10 includes a prime mover 20, a cabin 25 defining a sleeping portion 30 and a driving portion 35, an auxiliary power unit (APU) 40, and a plurality of vehicle accessories 45 and cabin accessories 47 (e.g., electronic communications, cabin lights, a primary and / or secondary HVAC system, primary and / or secondary HVAC fan(s), visors for the windows / windshield of the vehicle 10, cabin accessories, etc.). In this particular example, the prime mover 20 is an engine, particularly a diesel engine. The prime mover can provide sufficient power to operate (e.g., drive) the vehicle 10 and any of the plurality of vehicle accessories 45 and cabin accessories 47, for example, by generating power using an alternator connected to the prime mover. The APU 40 (auxiliary power unit) is an auxiliary power unit for the vehicle 10 that can be used when the prime mover is deactivated and can be charged while the vehicle 10 is being driven.

[0048] like Figure 1As partially shown in FIG, a trailer is connected to the vehicle 10 and carries a cargo compartment 50 provided with a transport refrigeration system (TRS) 52 configured to control the climate of the interior of the cargo compartment 50 .

[0049] The power supply requirement of the TRS is approximately 20 kW to 45 kW. Other vehicle accessory systems may require a similar amount of power supply. As can be understood, this power supply requirement will exceed the rated power of the vehicle's alternator.

[0050] The vehicle is provided with a power generation device for supplying power to the TRS or other electrical systems by directly converting mechanical power from the power take-off device into electrical power. Such a device can provide sufficient power to operate the TRS, HVAC or other vehicle systems.

[0051] Figure 2 Shown is supported on Figure 1 FIG. 1 is a simplified planar layout of equipment on a chassis 202 of an exemplary electric vehicle 10. The layout includes the chassis 202, which in this simplified example is illustrated by two longitudinally extending support members 204 and laterally extending cross members 206.

[0052] A pair of front wheels are supported on the front axle. An engine compartment 210 is defined between the two longitudinally extending support members 204, and a prime mover 20 (eg, a diesel engine) is disposed in the engine compartment and connected to a torque converter and a transmission disposed within a support housing 212 via shafts. Figure 2 As shown, the engine compartment 210 is defined as a relatively confined space. Specifically, it is defined by two longitudinally extending support members and a cross member extending between the support members behind a support housing 212 that accommodates the torque converter and the transmission.

[0053] Outside of the nacelle, on either side of the support structure 204 , are the exhaust treatment unit 214 and the APU 40 .

[0054] A propeller shaft 216 extends rearwardly from the support housing 212 (connected to a transmission within the support housing 212) and extends midway along the length of the chassis toward the rear wheels. The propeller shaft 216 is connected to differentials 218, 220 that drive each pair of rear wheels 222, 224.

[0055] Figure 3 and Figure 4An exemplary power generation assembly 300 for vehicle 10 is schematically shown. The power generation assembly includes a torque converter and a transmission, as described above, disposed within support housing 212, as described above. A power take-off 302 and a generator 304 are mounted on one side of support housing 212 to convert mechanical power into electrical power, as will be described in greater detail below, with generator 304 positioned alongside support housing 212.

[0056] The exemplary support housing 212 has a frusto-conical portion toward the engine side (eg, front side) of the housing coupled to a generally cylindrical portion toward the output side (eg, rear side) of the housing. Figure 4 As best shown, the frusto-conical portion generally houses a torque converter 402 having an engine-side input 404 (e.g., a shaft from the engine) and a transmission-side output 406 (e.g., a shaft extending from the torque converter to the transmission 408), while the transmission is housed within the generally cylindrical portion. In this example, both the engine-side input 404 and the transmission-side output 406 are rotatable about a common rotational axis 403 of the torque converter, which is coaxial with a central rotational axis 409 of the transmission 408. The torque converter may be a hydraulic torque converter configured to transfer torque from the engine-side input 404 to the transmission-side output 406 while allowing relative slip under certain conditions.

[0057] like Figure 4 As best shown in FIG. 2 , the power take-off 302 is mounted on a side portion of the support housing 212 having a slot therein for engaging a mechanical transfer device 410 within the support housing 212. The mechanical transfer device 410 is configured to transfer mechanical power from the engine-side input device 404 to an interface component that interfaces with the power take-off 302 to provide a rotational input to the power take-off 302. For example, the mechanical transfer device 410 may include one or more non-coaxial gears, or a laterally extending shaft and one or more bevel gears. In this particular example, the mechanical transfer device 410 includes an interface component in the form of a gear that is configured to rotate about an axis parallel to and laterally offset from the torque converter's axis of rotation 403, such that teeth of the gear can be engaged by corresponding teeth on an interface component of the power take-off 302 through the slot in the support housing.

[0058] In this example, power take-off 302 is configured to transmit a rotational input provided to a docking component of the power take-off to a rotational output having an output rotational axis laterally offset from the docking component. This allows power take-off 302 to provide mechanical power to a driven device (e.g., a generator) that is laterally separated from support housing 212. For example, the power take-off may include a docking component in the form of a gear that receives the rotational input and is rotatable about a first power take-off axis, and a rotational output component in the form of a shaft rotatable about a second power take-off axis, the shaft having teeth for engaging the docking component and a socket for connecting to the driven device.

[0059] The inventors have recognized the benefits and advantages of using commercial off-the-shelf (COTS) components in power generation assemblies. There is a market for power take-offs, which currently offer essentially the same power take-offs as described above. Such power take-offs are provided to the automotive industry to transfer mechanical power to hydraulic pumps (as described in the background).

[0060] In known power take-offs (PTOs) that power hydraulic pumps, the PTO receives a rotational input from a mechanical transfer device connected to the transmission-side output of a torque converter or the transmission itself (rather than the engine-side input). This transmission-side output or the transmission itself rotates at the engine's rotational speed when the torque converter is engaged. The PTO provides a rotational output to the hydraulic pump, resulting in a relatively low gear ratio between the torque converter and the PTO's rotational output, for example, between 1:1 and 1:1.5. This gear ratio is acceptable for driving conventional hydraulic pumps. Because the PTO is connected to the transmission-side output of the torque converter or the transmission (rather than the engine-side input), no mechanical power is transmitted to the PTO and hydraulic pump when the torque converter is disengaged (for example, when the engine is idling).

[0061] The inventors have found that although the COTS power take-off provides a satisfactory transmission ratio between the engine rotational speed and the rotational output of the hydraulic pump, the output rotational speed is relatively low for operating a generator.

[0062] The design theory of permanent magnet generators teaches that there is an optimal length to outer diameter ratio (L / D) for the rotor, which is determined as a function of the number of pole pairs p by the following equation:

[0063]

[0064] This equation is provided in the textbook “Design of Rotating Electrical Machines”, Juha Pyrhonen, Tapani Jokinen, Valeria Hrabovcova, © 2008 John Wiley & Sons, Ltd. ISBN: 978-0-470-69516-6 pp 297.

[0065] With an L / D configuration, the diameter of the rotor is varied to achieve adequate power generation for a given rotational speed. Thus, for a target amount of power generation, a relatively low rotational speed translates to a larger diameter, while a relatively high rotational speed translates to a smaller diameter.

[0066] As mentioned in the background of this application, previously considered arrangements include (i) having a large diameter generator connected to a power take-off via a drive shaft; or (ii) providing a series of gears or belt and pulley arrangements to increase the rotational speed of the generator.

[0067] The present disclosure provides a power generation assembly 300 that avoids the disadvantages associated with those previously considered arrangements by providing a compact generator 304 having a high power density that is directly connected to a power take-off 302 .

[0068] like Figure 4 As shown, the power generation assembly 300 is disposed within the engine compartment 210 of the vehicle 10, where limited space exists for providing accessories. A support housing 212 is supported on the frame of the engine compartment 210 by a plurality of damping supports 413 extending from the frame to mounting points on the support housing 212. The damping supports are configured to support the support housing 212 (and thereby the power take-off 302 and the generator 304) while allowing minor relative movement through extension, retraction, or flexure of the damping supports, thereby partially isolating the power generation assembly 300 from vibrations experienced by the frame of the engine compartment 210 during use.

[0069] The inventors have discovered that a power take-off (PTO) device that implements a relatively low gear ratio between the engine-side input of a torque converter and the rotary output of the PTO can be used to generate sufficient power for a transport refrigeration system (TRS) or comparable accessory device (e.g., an HVAC system) using a compact generator with a high-aspect-ratio rotor. For example, the generator rotor can have an L / D ratio of at least 2, such as at least 2.5. By using a relatively long rotor with a relatively small diameter, a rotor volume equivalent to that of a shorter rotor with a larger diameter can be achieved. Power generation is a function of rotor volume and rotational speed.

[0070] While conventional teaching in the art is to provide shorter, larger diameter rotors for optimal efficiency (as discussed above with respect to the L / D ratio), the inventors have recognized that lower efficiency may be acceptable in order to achieve a compact generator that reduces the complexity of the power generation components overall, as will become apparent from the discussion below.

[0071] Reference again Figure 3 and Figure 4 As an exemplary power generation assembly, the compact generator 304 may:

[0072] - Direct connection to the power take-off 302 within the scope of the engine compartment 210;

[0073] - is supported directly on the support housing 212, thereby eliminating any need for a separate damping support dedicated to supporting the generator;

[0074] - Power is generated for the TRS at relatively low rotational speeds (e.g., between 8 kW and 42 kW for supplying a TRS system with an operating power requirement of between 20 kW and 45 kW) thanks to the rotor's high L / D ratio, while having a relatively low diameter. This eliminates the need for any gearing or belt and pulley system between the power take-off and the generator, while allowing the use of a COTS power take-off that achieves a relatively low gear ratio between the engine input side of the torque converter and the rotary output to the generator.

[0075] like Figure 4 As shown, generator 304 extends along generator axis 305 from a first proximal end, where it is connected to power take-off 302, to a second distal end. The terms proximal and distal indicate proximity to a main body or support. Herein, they are used with respect to support and functional connection to power take-off 302. Since the first end is supported on the power take-off, this is referred to as the proximal end, while the opposite end is considered the distal end.

[0076] like Figure 4 As shown, generator 304 includes a support assembly at a first end that is configured to connect to a mating formation or assembly on power take-off 302. In this particular example, support assembly 414 is configured to be inserted into a receptacle opening of the power take-off, where the rotary output is disposed. Support assembly 414 can be secured to the power take-off by one or more fasteners, such as bolts.

[0077] The exemplary generator 304 includes a first bearing arrangement 416 and a second bearing arrangement 418 at a first end and a second end, respectively, for supporting a rotor shaft 422 of a rotor 420. In this example, the rotor shaft 422 is directly connected to the power take-off 302, particularly by means of a splined end of the rotor shaft 422 that interfaces with the rotational output of the power take-off 302. The first bearing arrangement 416 is supported by a support assembly 414, while the second bearing arrangement 418 is supported by an endshield of the generator, which is disposed at the second end of the generator 304. A housing wall 426 extends between the support assembly 414 and the endshield 424. The bearing arrangement can include any suitable bearing combination, such as a floating bearing and an axially locating bearing, or a single bearing toward one end of the generator, such as toward the distal end.

[0078] The exemplary generator 304 also includes a stator 428 disposed radially outside of the rotor 420. In this example, the stator includes a plurality of windings surrounding a stator core. Stator cables extend from the windings through the end shield 424 of the rotor for connection to a load. In this example, the generator is provided with a controller 430 configured to control the electrical connection of the stator cables to the load. Figure 4 As schematically shown in FIG, in this example, the controller is external to the generator housing and may be provided as part of the electrical system to which the generator is connected. However, in other examples, the controller may be integral to the generator. The operation of the controller will be described in further detail below with reference to a practical example.

[0079] Generator in Figure 5 , and in the following description particular reference is made to further details of the rotor and end shields.

[0080] like Figure 5 The rotor, shown partially, includes multiple slots for permanent magnets that terminate at the rotor's axial end faces, as shown by the V-shaped magnet end pairs. In this example, the rotor 420 has a laminated structure formed around a central core. Specifically, a rotor shaft 422 is provided, and a series of stamped laminates are provided on the rotor shaft 422 in an axially stacked arrangement, each laminate having punched holes that, when stacked together, provide elongated slots to receive the permanent magnets. The laminated structure provides a relatively inexpensive manufacturing process for the permanent magnet rotor. In this example, the rotor has six poles (i.e., three pole pairs), each pole including two permanent magnets arranged in a V-shape as shown (i.e., such that, in a plane perpendicular to the generator axis 305, at the azimuthal position corresponding to the respective pole, the cross-sectional profile of each permanent magnet provides branches of a V-shape that converge toward each other but do not touch toward the generator axis 305).

[0081] As explained above, the optimal L / D ratio of the rotor can be determined based on the number of pole pairs using the equation provided above. This yields an optimal L / D ratio of 0.45 for a 6-pole rotor (3 pole pairs). However, in this particular example, the rotor's L / D ratio is approximately 2.5, providing a laterally compact rotor. The larger L / D ratio allows the generator to be housed in a compact housing with a relatively small maximum diameter or characteristic lateral dimension (i.e., the longest line through a cross-section perpendicular to the generator axis 305 within a portion of the generator having a substantially constant cross-sectional profile). In this particular example, the maximum diameter and characteristic dimension do not exceed 150 mm, which is relatively low considering the generator's power output. In this example, the generator is configured to generate at least 8 kW at an engine speed of 500 rpm (corresponding to engine idle), rising to at least 40 kW at an engine speed of 2500 rpm. In other examples, larger devices may be possible within the available space, for example, with a maximum diameter and characteristic dimension of no more than 175 mm, or no more than 200 mm.

[0082] like Figures 3 to 5 As shown in each of the examples, assuming that support housing 212 has a relatively long axial extent along transmission axis 409, nacelle 210 has been configured to accommodate this axial extent, even with limited space laterally around support housing 212. It is considered advantageous to provide a laterally compact rotor and achieve a target rotor volume by extending its length. This can be achieved by providing a generator sized such that, relative to transmission axis 409, it has an axial extent that overlaps with or is within the axial extent of support housing 212. In this particular example, the axial extent of the generator overlaps with the axial extent of the support housing, with a first end naturally rearward of the forward end of support housing 212 and a second end extending beyond the extent of support housing 212 by a distance permitted by the configuration of nacelle 210. In this particular example, generator axis 305 and transmission axis 409 are substantially parallel.

[0083] Figure 5 An exemplary configuration of the endshield 424 at the second distal end of the rotor is shown in greater detail. As discussed above, the endshield 424 supports the second bearing arrangement. The endshield 424 also provides electrical and fluid cooling connections to the generator.

[0084] The fluid cooling connections are used to supply fluid cooling channels within the generator, which in this particular example are integrally formed with the housing wall 426, as shown in FIG. Figure 6As best shown, the fluid cooling connection can be connected to an external fluid cooling circuit. For example, the cooling fluid can be provided by a transport refrigeration system (TRS) carried by the vehicle.

[0085] Figure 6 3 is an exploded cross-sectional view of the housing taken along a plane perpendicular to the generator axis 305 to illustrate the presence of cooling channels in the wall of the housing. As can be appreciated, the cooling channels can be arranged in a serpentine manner so that laterally adjacent cooling channels are connected together at one end or the other of the housing.

[0086] Reference again Figure 5 , the end cap 424 provides inlet and outlet fluid ports 604 in fluid connection with the fluid passages of the housing ( Figure 5 For example, the end shield can include an internal manifold configured to fluidly connect an inlet port to the plurality of fluid channels 602 and an internal manifold configured to fluidly connect an outlet port to the plurality of fluid channels 602.

[0087] The end shield 424 also includes cable ports through which the stator cables are routed through the end shield for connection to the load.

[0088] By providing the cable ports and fluid ports 604 in the end shields, the profile of the generator along its axial length can be minimized. Figure 6 As shown, the end caps are configured so that the fluid ports (and any internal manifolds) do not intersect the cable ports.

[0089] Figure 5 Further details of generator 304 are shown, as described below. At the second distal end of generator 304, endshield 424 has an opening coaxial with the rotor that allows for proper assembly of endshield 424 and rotor 420. The opening is sealed using a first seal 502 and a second seal 504 spaced apart along the axis of the rotor. A retaining nut 506 is axially adjacent to second bearing assembly 418 and disposed on rotor shaft 422, limiting axial movement of rotor shaft 422 relative to a corresponding shoulder of endshield 424.

[0090] At a first end of generator 304 , there is a rotating seal 508 extending between an end portion of rotor shaft 422 and support assembly 414 .

[0091] In addition to being structurally mounted to the power take-off 302, the generator 304 is structurally mounted to the support housing 212. In this particular example, it is mounted to the support housing 212 via a bracket 510 that engages the housing 426 and is mounted to an attachment point 512 on the support housing 212. However, in other examples, any suitable mounting arrangement may be provided between the generator and the support housing 212.

[0092] Now refer to the above reference Figures 1 to 6 The vehicle 10 and power generation assembly 300 are described as examples of the use of the vehicle 10 to generate power using the power generation assembly 300 for a TRS.

[0093] In use, the vehicle 10 is operated by activating the prime mover 20 so that the engine-side input 404 of the torque converter 402 rotates within an operating range of rotational speeds. For example, the operating range of rotational speeds may be between 500 and 5000 rpm.

[0094] Because the mechanical transfer device 410 is connected to the engine-side input device 404, rather than downstream of the torque converter (i.e., connected to the transmission-side output device 406 or the transmission 408), mechanical power is transferred to the power output device 302 whenever the engine is active. In this example, there is no clutch to engage the power output device 302, which simplifies the device and reduces the number of mechanical failure points.

[0095] The power output 302 transmits mechanical power to rotate the rotor 420 of the generator 304. In this example, there is a gear ratio of 1:1.25 between the engine rotational speed (ie, the engine-side input 404) and the rotor 420 of the generator 304.

[0096] The controller 430 selectively electrically decouples and couples the generator 304 to the load network, which in this example includes a transport refrigeration system (TRS) and may also include the APU 40 for charging. The controller 430 thus switches between coupled and decoupled states of the generator.

[0097] When the controller is in the connected state, the rotation of the rotor relative to the stator generates current in the stator coils, which is delivered to the load network through the stator cables. This current generation causes a reaction force on the rotor. The voltage output of the generator 304 is a function of the rotational speed of the rotor.

[0098] In this example, the generator is configured to generate at least 8 kW of power for supply to the load when the engine rotates at 500 rpm (corresponding to a rotational speed of 625 rpm for rotor 420), and at least 40 kW of power when the engine rotates at 2500 rpm (corresponding to a rotational speed of 3125 rpm for rotor 420). The generator is configured to generate approximately 20 kW of power when the engine rotates at 1200 rpm (corresponding to a rotational speed of 1500 rpm for rotor 420). The controller 430 is configured to electrically decouple the generator from the load when the power generation components are in a high-voltage state to prevent power from being supplied to the load at an excessively high voltage. This control can be initiated based on any suitable parameters. For example, the controller 430 may receive a signal from a sensor monitoring the rotational speed of a component in the powertrain between the engine input and the generator (e.g., the engine-side input 404, a component of the mechanical transmission 410, a component of the power take-off 302, or the rotor 420 of the generator 304). Alternatively or additionally, the controller 430 may receive signals from sensors monitoring electrical parameters such as the voltage output of the generator, current or power in a load circuit coupled to the generator 304 .

[0099] In this particular example, controller 430 is configured to receive a signal including a rotational parameter corresponding to the rotational speed of an engine-side input device, determine whether the generator is in a high-voltage state based on the rotational parameter, and selectively electrically isolate (i.e., decouple) the generator when it determines that the generator is in a high-voltage state. In this example, a high-voltage state is determined when the rotational parameter indicates that the engine rotational speed is at least 2500 rpm (corresponding to a rotational speed of 3125 rpm for the generator's rotor 420). In other examples, any suitable rotational speed threshold can be set to determine a high-voltage state. The controller may include a power semiconductor switch to selectively electrically decouple and couple the generator 304 to the load.

[0100] In this particular example, the generator 304 is configured to provide between 8 and 42 kW of power to the load when the engine rotational speed is within the generator's operating range of 500 rpm to 2500 rpm, which corresponds to a rotor rotational speed of 625 rpm to 3125 rpm.

[0101] By using a controller to selectively electrically decouple generator 304 from the load during high-voltage conditions, the power generation assembly achieves a particularly simple mechanical arrangement while preventing the supply of power under excessive voltage. Previously considered arrangements (although relying on a drive shaft to power the generator) relied on a clutch to selectively mechanically decouple the generator from the power take-off. However, the use of a clutch increases the complexity of the power generation arrangement and the number of failure points.

[0102] Although specific examples of the present invention have been described herein with reference to being a semi-trailer, the term "vehicle" as used herein is intended to be broadly interpreted to include at least all trailers and trucks.

[0103] It should be understood that the present invention is not limited to the embodiments described above, and that various modifications and improvements may be made without departing from the concepts described herein. Except where mutually exclusive, any one of the features may be used separately or in combination with any other feature, and the present disclosure extends to and includes all combinations and subcombinations of one or more features described herein.

Claims

1. A power generation assembly for powering a transport refrigeration system (TRS) of a vehicle, the power generation assembly comprising: a torque converter having an engine-side input device and a transmission-side output device; a power take-off connected to the engine-side input of the torque converter, the power take-off having a rotational output; a permanent magnet generator having a rotor directly connected to the power take-off for power generation; The power generation assembly is configured to be housed in an engine compartment of a vehicle, and the power generation assembly is configured to generate at least 8 kW of power when the engine-side input device has a rotation speed of 500 rpm.

2. The power generation assembly according to claim 1, wherein: The power take-off is connected to the engine-side input of the torque converter via a clutchless connection.

3. The power generation assembly according to claim 1 or 2, wherein: The power output device provides a transmission ratio of 1:1.1 to 1:1.75 between the engine-side input device of the torque converter and the rotor of the permanent magnet generator.

4. The power generation assembly of claim 1, wherein: The torque converter is mounted within a support housing such that the axis of rotation of the torque converter is fixed relative to the support housing, and Wherein, the power output device and the permanent magnet generator are fixedly mounted to the support housing.

5. The power generation assembly according to claim 4, wherein: The support housing is provided with a damping support for connection to a frame of an engine compartment of the vehicle to allow the support housing to move relative to the frame, and The power take-off and the permanent magnet generator are mounted to the support housing so that in use the power take-off and the permanent magnet generator move together with the support housing relative to the frame.

6. The power generation assembly of claim 4, wherein: A transmission is connected to a transmission-side output device of the torque converter, the transmission being disposed within the support housing; wherein the permanent magnet generator is elongated along a generator axis about which the rotor rotates; and Wherein, relative to the rotation axis of the transmission, the axial extent of the permanent magnet generator overlaps with the axial extent of the support housing or is within the axial extent of the support housing.

7. The power generation assembly according to claim 6, wherein: The power take-off and the permanent magnet generator are configured such that the generator axis is substantially parallel to the transmission axis and / or the rotation axis of the engine-side input device.

8. The power generation assembly of claim 1, wherein: The permanent magnet generator includes a bearing arrangement configured to support the rotor, separate from any bearing arrangement of the power take-off.

9. The power generation assembly of claim 6, wherein: The permanent magnet generator has a rotor outer diameter D and a length L along the generator axis, wherein the length to outer diameter ratio L / D is at least 2.

10. The power generation assembly of claim 1, wherein: The permanent magnet generator has a rotor outer diameter D and a length L along the generator axis, wherein the L / D ratio is at least 200% of which is the number of extreme pairs.

11. The power generation assembly of claim 1 , comprising liquid cooling means for the permanent magnet generator.

12. The power generation assembly of claim 1, wherein: The permanent magnet generator includes an end shield at an axial end opposite to the power take-off, wherein the permanent magnet generator comprises a fluid port for connecting a liquid cooling circuit to a cooling channel within the permanent magnet generator, and wherein the fluid port is provided in the end shield; and / or Wherein, electrical terminals for the stator windings of the permanent magnet generator are arranged in the end shield.

13. The power generation assembly of claim 6, wherein: The permanent magnet generator is arranged in a generator housing, which has a diameter or a characteristic lateral dimension of not more than 200 mm at an axial position along the generator axis, the characteristic lateral dimension corresponding to the longest line passing through a cross section orthogonal to the generator axis within the portion of the permanent magnet generator having a substantially constant cross-sectional profile.

14. The power generation assembly of claim 6, wherein: The rotor has a laminated structure including a plurality of laminations, each lamination including a plurality of slots aligned along the generator axis to define elongated channels in which respective permanent magnets are received.

15. The power generation assembly of claim 1, wherein: The permanent magnet generator is configured to provide power to a load via a load circuit, the permanent magnet generator having an output voltage that is a function of a rotational speed of the rotor; The power generation assembly further includes a controller configured to selectively electrically isolate the permanent magnet generator based on a determination of a high voltage state of the power generation assembly.

16. The power generation assembly of claim 15, wherein: The controller determines the high voltage state of the power generating component based on a rotational parameter indicative of a rotational speed of the rotor or an electrical parameter indicative of a voltage, current, or power in the load circuit.

17. A vehicle comprising the power generation assembly of claim 1, wherein: The vehicle includes an engine compartment, and wherein the power generation assembly is disposed within the engine compartment.

18. The vehicle of claim 17, wherein: The power generation assembly is a power generation assembly according to claim 5, wherein the damping support extends between the frame of the nacelle and the support housing; wherein there are no supports extending between the frame of the nacelle and the power take-off; and There are no supports extending between the frame of the nacelle and the generator.

19. A vehicle according to claim 17 or 18, wherein A transport refrigeration system (TRS) is installed in the vehicle, and the permanent magnet generator is connected to the transport refrigeration system to provide power to the transport refrigeration system.

20. The vehicle of claim 19, wherein: Power is provided directly from the permanent magnet generator to the transport refrigeration system without any intermediate hydraulic system.

Images