Patent Application
20160159213
This disclosure relates to vehicle propulsion systems.
Known vehicle powertrain systems generate tractive torque for vehicle propulsion by converting combustible fuel and/or stored electric power to rotational torque that is transferred to vehicle drive wheels.
A wheel assembly for a vehicle includes a hub portion supporting a plurality of controllable variable length radially-oriented spoke elements supporting a conformable rim assembly supporting a tire element. The hub portion is concentric to an axis of rotation and includes a support structure. The controllable variable length radially-oriented spoke elements are perpendicular to the axis of rotation and each includes a first end mechanically coupled to the support structure of the hub portion, a length-varying actuator individually controllable to a selected length and a second end coupled to an inner periphery of the conformable rim assembly. The conformable rim assembly includes a plurality of segmented sections.
The above features and advantages, and other features and advantages, of the present teachings are readily apparent from the following detailed description of some of the best modes and other embodiments for carrying out the present teachings, as defined in the appended claims, when taken in connection with the accompanying drawings.
One or more embodiments will now be described, by way of example, with reference to the accompanying drawings, in which:
Referring now to the drawings, wherein the depictions are for the purpose of illustrating certain exemplary embodiments only and not for the purpose of limiting the same,
The engine 22 may be any suitable device that combusts fuel to generate torque, and is preferably configured to execute autostart and autostop operations. As shown the engine 22 couples to an isolator device 24 that reduces torsional engine vibration transmitted to other powertrain elements. The isolator 24 couples through a brake element 26 that couples to a node of a planetary gear set 42 of the gear train 40 via a shaft member or other suitable torque coupling device. The engine 22 and brake 26 are operationally controlled by an engine controller 25. The motor/generator 30 rotatably couples to another node of the planetary gear set 42. The motor/generator 30 can be any suitable non-combustion torque machine, and as shown is a multi-phase electrical motor including a rotor and stator that electrically connects to an inverter 32. A high-voltage battery 34 electrically connects via a high-voltage bus 33 to the inverter 32 that electrically powers the motor/generator 30 in response to control signals from an inverter controller 35. The planetary gear set 42 includes another node that rotatably couples through the gear train 40 to a differential gear set 44 that couples to a pair of axles 45, 46 to transfer torque to the wheels 60. The vehicle axles 45, 46 are oriented on a single, common axis of rotation of the wheels 60. The planetary gear set 42 can be any suitable gear set that multiplies and transfers torque inputs from torque generative devices such as the engine 22 and motor/generator 30. The powertrain configuration of the engine 22, motor/generator 30 and gear train 40 is illustrative. Other powertrain configurations that deliver tractive torque to the vehicle axles 45, 46 may be employed within the scope of the disclosure. Those skilled in the art appreciate that other unillustrated powertrain and vehicle components may be employed.
The vehicle 10 includes a plurality of user interface devices through which an operator commands operation of the vehicle. This is depicted as user interface controller 90 having operator input elements including an accelerator pedal 91, a brake pedal 92, a steering wheel 93 and an ignition switch 94. The depiction of the user interface devices is illustrative. Those skilled in the art appreciate that user interface devices may be in a variety of suitable forms. The vehicle includes a controller 15 that provides overarching control of the inverter controller 35, the engine controller 25, an electro-mechanical wheel controller 55, the user interface controller 90 and other vehicle controllers.
The terms controller, control module, module, control, control unit, processor and similar terms refer to any one or various combinations of Application Specific Integrated Circuit(s) (ASIC), electronic circuit(s), central processing unit(s), e.g., microprocessor(s) and associated non-transitory memory component in the form of memory and storage devices (read only, programmable read only, random access, hard drive, etc.). The non-transitory memory component is capable of storing machine readable instructions in the form of one or more software or firmware programs or routines, combinational logic circuit(s), input/output circuit(s) and devices, signal conditioning and buffer circuitry and other components that can be accessed by one or more processors to provide a described functionality. Input/output circuit(s) and devices include analog/digital converters and related devices that monitor inputs from sensors, with such inputs monitored at a preset sampling frequency or in response to a triggering event. Software, firmware, programs, instructions, control routines, code, algorithms and similar terms mean any controller-executable instruction sets including calibrations and look-up tables. Each controller executes control routine(s) to provide desired functions, including monitoring inputs from sensing devices and other networked controllers and executing control and diagnostic routines to control operation of actuators. Routines may be executed at regular intervals, for example each 100 microseconds. Alternatively, routines may be executed in response to occurrence of a triggering event. Communications between controllers and between controllers, actuators and/or sensors may be accomplished using a suitable communications link 16, e.g., a direct wired link, a networked communications bus link, or a wireless link. Communications includes exchanging data signals in any suitable form, including, for example, electrical signals via a conductive medium, electromagnetic signals via air, optical signals via optical waveguides, and the like.
The vehicle 10 includes a structural element 12 on which a vehicle hub 50 and accompanying bearing assembly mounts. The vehicle axle 46 passes through an opening in the vehicle hub 50 and couples to a spindle 56. The vehicle axle 46 rotates within the vehicle hub 50 and the bearing assembly. The structural element 12 and vehicle hub 50 may include other vehicle elements such as suspension components, braking components and the like, which are not shown.
The vehicle hub 50 provides a mounting platform for a stator 51 of a rotary transformer 52 and the spindle 56 provides a mounting platform for a rotor 53 of the rotary transformer 52. The stator 51 electrically connects to an inverter 54 that electrically connects to the battery 34 via high-voltage bus 33. Inverter 54 is operatively controlled by the electro-mechanical wheel controller 55. Alternatively, a second battery may be employed to supply electric power to the inverter 54. The rotary transformer 52 is a ring transformer or another suitable device that transfers electric power in the form of an alternating current between the stator 51 and the rotor 53 with an intervening air core.
One of the electro-mechanical wheels 60 is shown in detail, and includes a wheel hub 62 that fixedly mounts onto the spindle 56 and rotates therewith. The wheel hub 62 includes a support structure 63 that supports multiple controllable variable length linear actuators (linear actuators) 64 acting as spoke elements that support a conformable rim assembly 66 that supports a tire element 68. The wheel hub 62 is concentric to an axis of rotation defined by the axle 46. The linear actuators 64 are perpendicular to the axis of rotation in one embodiment, and each includes a first end mechanically coupled to the support structure 63 of the wheel hub 62 and a second end coupled to an inner periphery of the conformable rim assembly 66. Each of the linear actuators 64 is a length-varying actuator that is individually controllable to a selected length. The conformable rim assembly 66 includes a plurality of segmented sections. A power control and distribution system 65 electrically connects to the rotor 53 of the rotary transformer 52 and communicates with the electro-mechanical wheel controller 55. In this manner, the rotary transformer 52 electrically operatively couples to the linear actuators 64 via the power control and distribution system 65 to provide electric power for extension and retraction thereof to effect the variation in length.
The vehicle hub 202 and electrical stator 212 provide mounting for the axle 201 that couples to the spindle 204 on which the wheel hub 220 and electrical rotor 253 are mounted. The electrical rotor 253 corresponds to the rotor 53 of rotary transformer 52 (shown in
The linear actuators 240 are perpendicular to an axis of rotation of the axle 201 in the embodiment shown. Each linear actuator 240 includes a stator portion 242 and a moveable plunger 244. Each of the linear actuators 240 is individually controllable to achieve a selectable predetermined length. A distal end of the plunger 244 couples to an inner periphery of the conformable rim assembly 270. The linear actuators 240 can be any suitable form of electro-mechanical device that converts electrical power to linear translation to extend or retract the plunger 244, and thus extend or retract a corresponding portion of the conformable rim assembly 270. In one embodiment, the linear actuator 240 includes a 40 mm integrated air-strut and linear-motor actuators and an outside diameter of the rim portion of 900 mm (35 inch) having a width of 50 mm.
The conformable rim assembly 270 is a multi-piece annular device that includes suitable elements to structurally support to the tire assembly 280. As shown, the conformable rim assembly 270 includes six detached arc sections 272 that attach to corresponding ones of the six linear actuators 240. Alternatively, the six arc sections 272 may be flexibly attached one to another via a hinge or other suitable device at the interfaces therebetween.
The tire assembly 280 is a device that is structurally supported by and conforms to the conformable rim assembly 270, and can be any suitable device that provides traction between the wheel assembly 200 and a ground surface and also preferably provides some magnitude of elastic deformation between the wheel assembly 200 and the ground surface to absorb shocks. The tire assembly 280 conforms to the conformable rim assembly 270 when selected ones of the linear actuators 240 are extended or retracted. In one embodiment, the tire assembly 280 is a unitary annular inflatable pneumatic device. In one embodiment, the tire assembly 280 is a unitary non-inflatable pneumatic device. In one embodiment, the tire assembly 280 is a unitary hydraulically-filled device. In one embodiment, the tire assembly 280 is a track device. In one embodiment, the tire assembly 280 is a segmented device having a plurality of individual segments attached to corresponding segments of the conformable rim assembly 270, with each of the individual segments including a stand-alone pneumatic, hydraulic or solid device.
One operating principle associated with the electro-mechanical wheel assembly described herein is that it permits an active manipulation of position of the wheel's center by extension or retraction of individual ones of the linear actuators, including active manipulation of position of the wheel's center relative to a center of gravity of the vehicle. When the wheel's center is not concentric with the vehicle center of gravity, a net moment is generated by action of gravity on the wheel and the vehicle.
Positioning the wheel's center in an eccentric position relative to the vehicle center can generate forward or reverse motion of the vehicle or assist motion generated in part by torque applied to the axle by a conventional rotary electric motor/generator, an engine or a combination thereof. When torque is applied to the axle by a combination of an engine and an electric motor/generator coupled with a planetary gear set, a power-split propulsion system can be formed that includes the electro-mechanical wheel acting as one of the motor/generators. Specifically, the electro-mechanical wheel may be used as an output-coupled motor/generator in an input-power-split hybrid propulsion system. The electro-mechanical wheel assembly 200 also is able to apply wheel eccentricity to effect braking when the vehicle is in motion and to effect vehicle balancing when the vehicle is at a stopped position.
The detailed description and the drawings or figures are supportive and descriptive of the present teachings, but the scope of the present teachings is defined solely by the claims. While some of the best modes and other embodiments for carrying out the present teachings have been described in detail, various alternative designs and embodiments exist for practicing the present teachings defined in the appended claims.
