Patent ID: 12247658

DETAILED DESCRIPTION

While the concepts of the present disclosure are susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and will be described herein in detail. It should be understood, however, that there is no intent to limit the concepts of the present disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives consistent with the present disclosure and the appended claims.

References in the specification to “one embodiment,” “an embodiment,” “an illustrative embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may or may not necessarily include that particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to effect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. Additionally, it should be appreciated that items included in a list in the form of “at least one A, B, and C” can mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C). Similarly, items listed in the form of “at least one of A, B, or C” can mean (A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C).

In the drawings, some structural or method features, such as those representing devices, modules, instructions blocks and data elements, may be shown in specific arrangements and/or orderings for ease of description. However, it should be appreciated that such specific arrangements and/or orderings may not be required. Rather, in some embodiments, such features may be arranged in a different manner and/or order than shown in the illustrative figures. Additionally, the inclusion of a structural or method feature in a particular figure is not meant to imply that such feature is required in all embodiments and, in some embodiments, may not be included or may be combined with other features.

In some embodiments, schematic elements used to represent blocks of a method may be manually performed by a user. In other embodiments, implementation of those schematic elements may be automated using any suitable form of machine-readable instruction, such as software or firmware applications, programs, functions, modules, routines, processes, procedures, plug-ins, applets, widgets, code fragments and/or others, for example, and each such instruction may be implemented using any suitable programming language, library, application programming interface (API), and/or other software development tools. For instance, in some embodiments, the schematic elements may be implemented using Java™, C++ ™, and/or other programming languages. Similarly, schematic elements used to represent data or information may be implemented using any suitable electronic arrangement or structure, such as a register, data store, table, record, array, index, hash, map, tree, list, graph, file (of any file type), folder, directory, database, and/or others, for example.

Further, in the drawings, where connecting elements, such as solid or dashed lines or arrows, are used to illustrate a connection, relationship, or association between or among two or more other schematic elements, the absence of any such connection elements is not meant to imply that no connection, relationship, or association can exist. In other words, some connections, relationships, or associations between elements may not be shown in the drawings so as not to obscure the disclosure. In addition, for ease of illustration, a single connecting element may be used to represent multiple connections, relationships, or associations between elements. For example, where a connecting element represents a communication of signals, data or instructions, it should be understood by those skilled in the art that such element may represent one or multiple signal paths (e.g., a bus), as may be needed, to effect the communication.

Referring now toFIG.1, an illustrative drive system100for a vehicle includes a transmission120. The transmission120is configured to receive rotational power supplied by a drive unit102and provide the rotational power to a load (e.g., an axle132and wheels134A,134B mounted thereto) in use thereof. The transmission120includes an input shaft122, an output shaft124, and a park system200(seeFIG.2). The input shaft122includes, or is otherwise embodied as, any structure or collection of structures configured to receive torque/rotational power from the drive unit102. The output shaft124includes, or is otherwise embodied as, any structure or collection of structures configured to transmit torque/rotational power from the input shaft122to a load, which, in addition to the axle132and the wheels134A,134B, may include one or more transaxles, differentials, transfer boxes, final drives, and/or wheels, for example. As discussed below, the park system200includes at least one component in direct contact with the output shaft124. As will be apparent from the discussion that follows, the park system200is configured to selectively brake the output shaft124during a park operational mode of the transmission120.

Referring now toFIG.2, the illustrative park system200includes a park actuation assembly210. Among other things, the park actuation assembly210includes a park gear310(seeFIG.3) arranged in direct contact with the output shaft124as indicated inFIG.3. In particular, the park gear310receives the output shaft124such that inner teeth or splines312of the park gear310mate or mesh with corresponding features (e.g., grooves, notches, recesses, channels, or the like) of the output shaft124. Interaction between the complementary features of the park gear310and the output shaft124couples the park gear310and the output shaft124for common rotation and/or lack thereof.

The illustrative park system200includes a rotary actuator220coupled to the park actuation assembly210. The actuator220includes, or is otherwise embodied as, any electric motor, electric power plant, electric drive unit, or the like configured to supply rotational power to drive operation of the park actuation assembly210, as further discussed below. In some embodiments, the actuator220includes, or is otherwise embodied as, a brushed DC motor, a brushless DC motor, a switched reluctance motor, a universal AC/DC motor, an induction motor, a torque motor, a synchronous motor, a doubly-fed electric machine, an ironless or coreless rotor motor, a pancake or axial rotor motor, a servo motor, a stepper motor, a linear motor, or the like. Additionally, in some embodiments, the actuator220includes, or is otherwise embodied as, any device or collection of devices capable of converting electrical energy to rotational power to drive operation of the park actuation assembly210.

The park system200illustratively includes an actuation linkage230coupled between the actuator220and the park actuation assembly210. As described in further detail below, the actuation linkage230includes a number of mechanical and/or electromechanical structures that cooperate to operatively couple the actuator220to the park actuation assembly210. Consequently, in use of the transmission120, the actuator220drives operation of the park actuation assembly210through the actuation linkage230to establish a plurality of operating states of the park system200. Those operating states include an engaged state400(seeFIG.4), a disengaged state500(seeFIG.5), and a staged state600(seeFIG.6), which are further discussed below. In the engaged state400of the park system200, rotation of the park gear310is constrained to resist rotation of the output shaft124. In the disengaged state500of the park system200, rotation of the park gear310is permitted to allow rotation of the output shaft124. The staged state600of the park system200, which is distinct from the engaged state400and the disengaged state500, facilitates a transition to the engaged state400in the event of an electrical failure or in the event that input (e.g., from an operator) to operate in a park operating mode is received by a control system700.

The park system200of the present disclosure utilizes the electric actuator220without, and in place of, a mechanically-powered (e.g., hydraulically or pneumatically-powered) actuator to drive operation of the park actuation assembly210through the actuation linkage230in the aforesaid operational states. It should be appreciated that the illustrative park system200provides a mechanism for engaging (i.e., in the engaged state400) and disengaging (i.e., in the disengaged state500) the park actuation assembly210without an external device. Furthermore, as will be apparent from the discussion that follows, the illustrative staged state600of the park system200provides a fail-to-park operational mode to immediately transition the park system200to the engaged state400in an event of an electrical failure (e.g., a loss of power).

In the illustrative embodiment, the transmission120includes a control system700(seeFIG.7) that is configured to control operation of various components of the transmission120(e.g., one or more clutches, an electro-hydraulic system138) and operation of the park system200(e.g., the actuator220). The control system700includes a controller702that is communicatively coupled to various electromechanical components of the park system200, among other things. Methods and/or activities that may be performed by the controller702to control operation of the park system200are described in greater detail below with reference toFIGS.8-11.

Referring again toFIG.1, it should be appreciated that the illustrative transmission120, and the drive system100incorporating the transmission120, are adapted for use in one or more vehicles employed in a variety of applications. In some embodiments, the transmission120may be adapted for use with, or otherwise incorporated into, fire and emergency vehicles, refuse vehicles, coach vehicles, RVs and motorhomes, municipal and/or service vehicles, agricultural vehicles, mining vehicles, specialty vehicles, energy vehicles, defense vehicles, port service vehicles, construction vehicles, and transit and/or bus vehicles, just to name a few. Additionally, in some embodiments, the transmission120may be adapted for use with, or otherwise incorporated into, tractors, front end loaders, scraper systems, cutters and shredders, hay and forage equipment, planting equipment, seeding equipment, sprayers and applicators, tillage equipment, utility vehicles, mowers, dump trucks, backhoes, track loaders, crawler loaders, dozers, excavators, motor graders, skid steers, tractor loaders, wheel loaders, rakes, aerators, skidders, bunchers, forwarders, harvesters, swing machines, knuckleboom loaders, diesel engines, axles, planetary gear drives, pump drives, transmissions, generators, and marine engines, among other suitable equipment.

In the illustrative embodiment, the transmission120includes one or more clutches (not shown). The one or more clutches may be included in, or otherwise adapted for use with, the electro-hydraulic system138and coupled between the input shaft122and the output shaft124to selectively transmit rotational power between the shafts122,124in one or more operating modes of the transmission120. Each of the one or more clutches may be selectively engageable in response to one or more fluid pressures applied thereto.

In the illustrative embodiment, the drive unit102is embodied as, or otherwise includes, any device capable of producing rotational power to drive other components (e.g., a torque converter108and the transmission120) of the drive system100in use thereof. In some embodiments, the drive unit102may be embodied as, or otherwise include, an internal combustion engine, diesel engine, electric motor, or other power-generating device. In any case, the drive unit102is configured to rotatably drive an output shaft104that is coupled to an input or pump shaft106of a torque converter108.

The input or pump shaft106of the illustrative torque converter108is coupled to an impeller or pump110that is rotatably driven by the output shaft104of the drive unit102. The torque converter108further includes a turbine112that is coupled to a turbine shaft114. In the illustrative embodiment, the turbine shaft114is coupled to, or integral with, the input shaft122of the transmission120.

The illustrative torque converter108also includes a lockup clutch136connected between the pump110and the turbine112of the torque converter108. The torque converter108is operable in a so-called “torque converter” mode during certain operating conditions, such as during vehicle launch, low speed conditions, and certain gear shifting conditions, for example. In the torque converter mode, the lockup clutch136is disengaged and the pump110rotates at the rotational speed of the drive unit output shaft104while the turbine112is rotatably actuated by the pump110through a fluid (not shown) interposed between the pump110and the turbine112. In this operational mode, torque multiplication occurs through the fluid coupling such that the turbine shaft114is exposed to more torque than is being supplied by the drive unit102. The torque converter108is alternatively operable in a so-called “lockup” mode during other operating conditions, such as when torque multiplication is not needed, for example. In the lockup mode, the lockup clutch136is engaged and the pump110is thereby secured directly to the turbine112so that the drive unit output shaft104is directly coupled to the input shaft124of the transmission118through the torque converter108.

In the illustrative embodiment, the transmission120includes an internal pump118configured to pressurize, and/or distribute fluid toward, one or more fluid (e.g., hydraulic fluid) circuits thereof. In some embodiments, the pump118may be configured to pressurize, and/or distribute fluid toward, a main circuit, a lube circuit, an electro-hydraulic control circuit, and/or any other circuit incorporated into the electro-hydraulic system138, for example. It should be appreciated that in some embodiments, the pump118may be driven by a shaft116that is coupled to the output shaft104of the drive unit102. In this arrangement, the drive unit102can deliver torque to the shaft116for driving the pump118and building pressure within the different circuits of the transmission120.

The illustrative transmission120includes a gearing system126coupled between the input shaft122and the output shaft124. It should be appreciated that the gearing system126may include one or more gear arrangements (e.g., planetary gear arrangements, epicyclic drive arrangements, etc.) that provide, or are otherwise associated with, one or more gear ratios. When used in combination with the one or more clutches and the electro-hydraulic system138under control by the controller702, the gearing system126may provide, or otherwise be associated with, one or more operating ranges selectable by an operator.

The output shaft124of the transmission120is illustratively coupled to, or otherwise integral with, a propeller shaft128. The propeller shaft128is coupled to a universal joint130which is coupled to, and rotatably drives, the axle132and the wheels134A,134B. In this arrangement, the output shaft124drives the wheels134A,134B through the propeller shaft128, the universal joint130, and the axle132in use of the drive system100. Of course, it should be appreciated that, in other embodiments, the output shaft124may drive the wheels134A,134B through another suitable mechanism and/or collection of structures.

The illustrative transmission120includes the electro-hydraulic system138that is fluidly coupled to the gearing system126via a number (i.e., J) of fluid paths1401-140J, where J may be any positive integer. The electro-hydraulic system138is configured to receive control signals provided by various electro-hydraulic control devices (not shown), such as one or more sensors and one or more flow and/or pressure control devices, for example. In response to those control signals, and under control by the controller702, the electro-hydraulic system138selectively causes fluid to flow through one or more of the fluid paths1401-140Jto control operation (e.g., engagement and disengagement) of one or more friction devices (e.g., the one or more clutches) included in, or otherwise adapted for use with, the gearing system126.

Of course, it should be appreciated that the one or more friction devices may include, but are not limited to, one or more brake devices, one or more torque transmitting devices (i.e., clutches), and the like. Generally, the operation (e.g., engagement and disengagement) of the one or more friction devices is controlled by selectively controlling the friction applied by, or otherwise associated with, each of the one or more friction devices, such as by controlling fluid pressure applied to each of the friction devices, for example. In the illustrative embodiment, which is not intended to be limiting in any way, the electro-hydraulic system138may be coupled to, or otherwise adapted for use with, one or more brakes. Similar to the clutches, each of the one or more brakes may be controllably engaged and disengaged via fluid pressure supplied by the electro-hydraulic system138. In any case, changing or shifting between the various gears of the transmission120is accomplished by selectively controlling the friction devices via control of fluid pressure within the number of fluid paths1401-140J.

In the illustrative drive system100shown inFIG.1, the torque converter108and the transmission120include a number of sensors configured to produce sensor signals that are indicative of one or more operating states of the torque converter108and the transmission120, respectively. For example, the torque converter108illustratively includes a speed sensor146that is configured to produce a speed signal corresponding to the rotational speed of the pump shaft106, which rotates at the same speed as the output shaft104of the drive unit102in use of the drive system100. The speed sensor146is electrically connected to a pump speed input (i.e., PS) of the controller702via a signal path152, and the controller702is operable to process the speed signal produced by the speed sensor146to determine the rotational speed of the pump shaft106/drive unit output shaft104.

In the illustrative drive system100, the transmission120includes a speed sensor148that is configured to produce a speed signal corresponding to the rotational speed of the transmission input shaft122, which rotates at the same speed as the turbine shaft114of the torque converter108in use of the system100. The input shaft122of the transmission120may be directly coupled to, or otherwise integral with, the turbine shaft114. Of course, it should be appreciated that the speed sensor148may alternatively be configured to produce a speed signal corresponding to the rotational speed of the turbine shaft114. Regardless, the speed sensor148is electrically connected to a transmission input shaft speed input (i.e., TIS) of the controller702via a signal path154, and the controller702is operable to process the speed signal produced by the speed sensor148to determine the rotational speed of the turbine shaft114/transmission input shaft124.

Further, in the illustrative system100, the transmission120includes a speed sensor150that is configured to produce a speed signal corresponding to the rotational speed and direction of the output shaft124of the transmission120. The speed sensor150is electrically connected to a transmission output shaft speed input (i.e., TOS) of the controller702via a signal path156. The controller702is configured to process the speed signal produced by the speed sensor150to determine the rotational speed of the transmission output shaft124.

In some embodiments, the electro-hydraulic system138includes one or more actuators configured to control various operations within the transmission120. For example, the electro-hydraulic system138may include a number of actuators that are electrically connected to a number (i.e., J) of control outputs CP1-CPJof the controller702via a corresponding number of signal paths721-72J, where J may be any positive integer as described above. Each of the actuators may receive a corresponding one of the control signals CP1-CPJproduced by the controller702via one of the corresponding signal paths721-72J. In response thereto, each of the actuators may control the friction applied by each of the friction devices by controlling the pressure of fluid within one or more corresponding fluid passageway1401-140J, thereby controlling the operation of one or more corresponding friction devices based on information provided by the various speed sensors146,148, and/or150in use of the system100.

In the illustrative embodiment, the drive system100includes a drive unit controller160having an input/output port (I/O) that is electrically coupled to the drive unit102via a number (i.e., K) of signal paths162, wherein K may be any positive integer. The drive unit controller160is operable to control and manage the overall operation of the drive unit102. The drive unit controller160includes a communication port (i.e., COM) which is electrically connected to a similar communication port (i.e., COM) of the controller702via a number (i.e., L) of signal paths164, wherein L may be any positive integer. It should be appreciated that the one or more signal paths164may be referred to collectively as a data link. Generally, the drive unit controller160and the transmission controller702are operable to share information via the one or more signal paths164. In one embodiment, for example, the drive unit controller160and the transmission controller702are operable to share information via the one or more signal paths164in the form of one or more messages in accordance with a Society of Automotive Engineers (SAE) J-1939 communications protocol. Of course, it should be appreciated that this disclosure contemplates other embodiments in which the drive unit controller160and the transmission controller702are operable to share information via the one or more signal paths164in accordance with one or more other communication protocols (e.g., from a conventional databus such as J1587 data bus, J1939 data bus, IESCAN data bus, GMLAN, Mercedes PT-CAN).

Referring again toFIG.2, the park actuation assembly210illustratively includes the park gear310, a park pawl314(best seen inFIG.3), a plurality of rollers214, and a ramp216. The park pawl314is movable to directly contact the park gear310(e.g., in the engaged state400of the park system200) and to be spaced from, and not in direct contact with, the park gear310(e.g., in the disengaged state500). At least one of the rollers214is movable along the ramp216(i.e., in the direction indicated by arrow218) to cause contact between the park pawl314and the park gear310. At least one of the rollers214is movable along the ramp216(i.e., in the direction indicated by arrow222) to cause the park pawl314to be spaced from the park gear310. The rollers214may be coupled together for common movement along and/or parallel to the ramp216by a carriage or carrier (not shown).

In the illustrative embodiment, the rollers214are operatively coupled to, and attached to, a rod280of the actuation linkage230that, as discussed below, is adapted for translation along a longitudinal axis282. In particular, a flanged end284of the rod280is configured for direct interaction with the rollers214. Although the rod280is described herein as a component of the actuation linkage230, the rod280may be incorporated into the park actuation assembly210and considered a component of the park actuation assembly210, at least in some embodiments.

In operation of the park system200(e.g., in or immediately prior to the engaged state400), the rod280translates along the axis282to drive movement of the rollers214attached to the rod280along the ramp216in the direction218. Additionally, in operation of the park system200(e.g., in or immediately prior to the disengaged state500), the rod280translates along the axis282such that the rod280is spaced from, and not in direct contact with, the rollers214, thereby permitting movement of the rollers214along the ramp216in the direction indicated by arrow222.

The illustrative actuation linkage230of the park system200includes a screw240, a nut250, a lever260, a sleeve270, the rod280, a collar290, and a spring296. Interaction between those components is further discussed below. Throughout operation of the park system200, the screw240, the nut250, the lever260, the sleeve270, the rod280, the collar290, and the spring296cooperate to operatively couple the actuator220to the park actuation assembly210.

The screw240of the illustrative actuation linkage230is directly coupled to the actuator220to receive rotational power therefrom. The screw240extends along a longitudinal axis242arranged parallel to the longitudinal axis282. The screw240illustratively includes external threads244adapted to mate with corresponding features of the nut250. In the illustrative embodiment, rotation of the actuator220in one direction (e.g., a clockwise direction) drives rotation of the screw240to cause translation of the screw240along the axis242in a direction indicated by arrow246. Additionally, in the illustrative embodiment, rotation of the actuator220in another direction (e.g., a counterclockwise direction) drives rotation of the screw240to cause translation of the screw240along the axis242in a direction indicated by arrow248.

The nut250of the illustrative actuation linkage230is threadably locked to the screw240for translation along the longitudinal axis242in response to rotation of the screw240. The nut250includes internal features (e.g., internal threads complementary to the external threads244) to lock the nut250to the screw240. In the illustrative embodiment, the internal features of the nut250and the external threads244of the screw240establish a self-locking engagement mechanism between the components240,250. Consequently, rotation of the screw240by the actuator220is required to enable movement of the nut250along the longitudinal axis242in use of the park system200. However, in other embodiments, it should be appreciated that other mechanical devices may be utilized in lieu of the screw240and the nut250to transfer drive from the actuator220. In one example, drive may be transferred from the actuator220by an axial cam coupled to the actuator220and a follower coupled to the axial cam.

The lever260of the illustrative actuation linkage230is directly coupled to the nut250at one end262thereof and directly coupled to the sleeve270at another end264thereof arranged opposite the end262. The lever260illustratively includes, or is otherwise embodied as, a link266that serves to interconnect the nut250and the sleeve270to coordinate movement of the nut250along the longitudinal axis242with movement of the sleeve270along the longitudinal axis282. In some embodiments, the link266may include, or otherwise be embodied as, a resilient and/or flexible structure capable of some degree of deformation in use of the park system200.

The sleeve270of the illustrative actuation linkage230is slidable along the longitudinal axis282relative to the rod280and mounted on the rod280to permit translation along the axis282. Throughout operation of the park system200, the sleeve270is arranged in direct contact with the spring296. Such contact biases the sleeve270away from movement along the longitudinal axis282toward the park actuation assembly210. The sleeve270includes lobes272,274arranged opposite one another and a core276interconnecting the lobes272,274. The lobes272,274each have a diameter greater than a diameter of the core276.

The rod280of the illustrative actuation linkage230supports the sleeve270and is adapted for translation along the longitudinal axis282as mentioned above. The rod280also supports the spring296for extension and compression along the longitudinal axis282. Translation of the rod280along the longitudinal axis282is best seen inFIGS.4-6. As further discussed below with reference toFIG.6, the rod280is constrained against translation along the longitudinal axis282toward the park actuation assembly210in the staged state600of the park system200.

The collar290of the illustrative actuation linkage230is affixed to the rod280for translation therewith along the longitudinal axis282in operation of the park system200. The collar290illustratively includes a neck292and a body294interconnected with the neck292. The neck292has a first diameter and the body294has a second diameter greater than the first diameter. The neck292of the collar290is configured for direct contact with the sleeve270in each of the engaged and disengaged states400,500of the park system200as best seen inFIGS.4and5.

The spring296of the actuation linkage230extends along the longitudinal axis282between the sleeve270and the rollers214of the park actuation assembly210. An abutment410(seeFIG.4) arranged adjacent the park actuation assembly210contacts the spring296to preload the spring296throughout operation of the park system200. Movement of the sleeve270along the longitudinal axis282toward the park actuation assembly210drives compression of the spring296, at least in some embodiments. Additionally, in at least some embodiments, movement of the sleeve270along the longitudinal axis282away from the park actuation assembly210drives extension of the spring296.

The illustrative park system200includes a latch system254operable to at least partially restrict movement of the collar290, and thereby the rod280, along the longitudinal axis282in the staged state600of the system200. The latch system254illustratively includes a latch256, a latch solenoid258, and a sensor368(seeFIG.3). The latch256includes, or is otherwise embodied as, an arm movable to directly contact the collar290. The latch solenoid258includes, or is otherwise embodied as, one or more electric actuators to drive movement of the latch256between a released position456(seeFIG.4) and a deployed position658(seeFIG.6). As discussed below with reference toFIGS.4and5, in the released position456, the latch256is spaced from the collar290. As discussed below with reference toFIG.6, in the deployed position658, the latch256directly contacts the collar290. The sensor368includes, or is otherwise embodied as, one or more monitoring devices capable of detecting a position of the collar290along the longitudinal axis282in use of the park system200.

Referring now toFIG.3, the park gear310and the park pawl314of the illustrative park actuation assembly210are depicted in greater detail. The teeth or splines312of the park gear310at least partially define an inner diameter ID of the park gear310. Keys316of the park gear310at least partially define an outer diameter OD of the park gear310. The park pawl314includes a catch318sized to be received in a notch320located between each pair of circumferentially adjacent keys316. In the engaged state400of the park system200, the catch318is received in a notch320such that the park pawl314resists and/or prevents rotation of the park gear310and the output shaft124. In the disengaged state500of the park system200, the catch318is disposed outside each notch320to permit rotation of the park gear310and the output shaft124.

In the illustrative embodiment, the park pawl314is mounted to, and/or at least partially received by, a housing330of the park actuation assembly210. The illustrative housing330includes a cylinder block332having a central passageway334through which the longitudinal axis282extends. In at least some embodiments, a portion of the park pawl314extends at least partway through the cylinder block332into the passageway334. Further, in at least some embodiments, the rod280, the spring296, and the rollers214are at least partially arranged in the passageway334, and the ramp216is formed by an interior surface (not shown) of the cylinder block332that at least partially defines the passageway334.

The illustrative park system200includes a mounting frame340supporting various structures of the park system200. The mounting frame340includes an upper mount block342and a pair of lower hangers344,346appended to the upper mount block342that extend downwardly away from the upper mount block342in a vertical direction V. The upper mount block342includes a base348and an extension350interconnected with the base348that extends upwardly therefrom in the vertical direction V. The upper mount block342at least partially supports the latch system254, the lever260, the sleeve270, the rod280, the collar290, and the spring296. The lower hangers344,346at least partially support the screw240, the nut250, and the lever260.

The upper mount block342of the illustrative mounting frame340is at least partially aligned with the longitudinal axis282in the vertical direction V. In the illustrative embodiment, the upper mount block342extends at least partway around the longitudinal axis282and supports the rod280such that the rod280extends along the longitudinal axis282. The latch256, the latch solenoid258, and the sensor368are coupled to, and supported by, the upper mount block342. A ring462(seeFIG.4) formed in the lever260receives a post444of the upper mount block342such that the lever260is pivotally coupled to the upper mount block342.

The lower hangers344,346of the illustrative mounting frame340are at least partially aligned with the longitudinal axis242in the vertical direction V. In the illustrative embodiment, each of the lower hangers344,346extends all the way around the longitudinal axis242, and the hangers344,346cooperate to support the screw240such that the screw240extends along the longitudinal axis242. The hangers344,346limit longitudinal translation of the screw240and the nut250along the axis242during operation of the park system200.

Referring now toFIG.4, operation of the park system200in the engaged state400is illustrated. As discussed above, rotation of the park gear310is constrained by the park pawl314in the engaged state400of the park system200to resist rotation of the output shaft124and establish a park operating mode of the transmission120. In the engaged state400, the electric actuator220drives rotation of the screw240and corresponding translation of the nut250along the longitudinal axis242in the direction indicated by arrow402. As a result, the nut250is disposed in close proximity to, and/or in contact with, the lower hanger346of the mounting frame340in the engaged state400of the park system200. For the sake of illustration, translation of the nut250along the axis242in the direction indicated by arrow402corresponds to rightward linear movement of the nut250toward the lower hanger346.

Due to the operative coupling between the nut250and the sleeve270provided by the lever260, translation of the nut250along the axis242in the direction indicated by arrow402drives translation of the sleeve270along the longitudinal axis282in the direction indicated by arrow404. Additionally, the collar290contacts the sleeve270in the engaged state400of the park system200and applies a contact force (not shown) to the sleeve270in the direction indicated by arrow404. In some embodiments, translation of the sleeve270along the longitudinal axis282in the direction indicated by arrow404may be accompanied by, or may at least partially cause, corresponding translation of the rod280and the collar290in the direction indicated by arrow404. In such embodiments, translation of the rod280in the direction indicated by arrow404may cause movement of the rollers214along the ramp216to place the catch318of the park pawl314in the notch320of the park gear310.

In the engaged state400of the park system200, the latch solenoid258is retracted such that the latch256is in the released position456. As a result, movement of the rod280and the collar290is not restricted or constrained by the latch256in the engaged state400. In some embodiments, the latch solenoid258is de-energized, powered off, or de-activated in the engaged state400. In other embodiments, however, the latch solenoid258may be energized, powered on, or activated in the engaged state400of the park system200.

Referring now toFIG.5, operation of the park system200in the disengaged state500is illustrated. As discussed above, rotation of the park gear310is permitted by the park pawl314to allow rotation of the output shaft124in one or more non-park operating modes (e.g., one or more forward drive mode(s), reverse drive modes(s), or neutral mode(s)) of the transmission120. In the disengaged state500, the electric actuator220drives rotation of the screw240and corresponding translation of the nut250along the longitudinal axis242in the direction indicated by arrow506. As a result, the nut250is disposed in close proximity to, and/or in contact with, the lower hanger344of the mounting frame340in the disengaged state500of the park system200. For the sake of illustration, translation of the nut250along the axis242in the direction indicated by arrow506corresponds to leftward linear movement of the nut250toward the lower hanger344.

Due to the operative coupling between the nut250and the sleeve270provided by the lever260, translation of the nut250along the axis242in the direction indicated by arrow506drives translation of the sleeve270along the longitudinal axis282in the direction indicated by arrow508. The collar290contacts the sleeve270in the disengaged state500of the park system200and applies a contact force to the sleeve270in the direction indicated by arrow404. In the illustrative embodiment, translation of the sleeve270along the longitudinal axis282in the direction indicated by arrow508causes corresponding translation of the rod280and the collar290in the direction indicated by arrow508. Consequently, translation of the rod280in the direction indicated by arrow508causes movement of the rollers214along the ramp216to place the catch318of the park pawl314outside of the notch320of the park gear310.

In the disengaged state500of the park system200, similar to the engaged state400, the latch solenoid258is retracted such that the latch256is in the released position456. As a result, movement of the rod280and the collar290is not restricted or constrained by the latch256in the disengaged state500. In some embodiments, the latch solenoid258is de-energized, powered off, or de-activated in the disengaged state500. In other embodiments, however, the latch solenoid258may be energized, powered on, or activated in the disengaged state500of the park system200.

Referring now toFIG.6, operation of the park system200in the disengaged state600is illustrated. In the illustrative embodiment, as mentioned above, the staged state600is separate and distinct from the engaged and disengaged states400and500. In the staged state600, rotation of the park gear310is at least partially permitted by the park pawl314to allow rotation of the output shaft124. Thus, at least in some embodiments, the staged state600may correspond to, or otherwise be associated with, a non-park operating mode of the transmission120which provides a failure-to-park mechanism.

In some embodiments, the staged state600of the park system200may correspond to an intermediate operational stage between the engaged state400and the disengaged state500. In any case, as mentioned above, the staged state600facilitates, provides, and/or effects a transition to the engaged state400in an event of an electrical failure. Additionally, the staged state600may facilitate a transition to the engaged state400in response to input (i.e., received by the controller702) indicative of user selection of a park operating mode of the transmission102. It should be appreciated that in use of the park system200, an electrical failure (e.g., a loss of power, abnormal electric current, a transient fault, a persistent fault, an asymmetric fault, a symmetric fault, or any other electrical fault) may impact operation of the electric actuator220and/or the latch solenoid258, among other electrically-powered devices included in the transmission120.

In the staged state600, the electric actuator220drives rotation of the screw240and corresponding translation of the nut250along the longitudinal axis242in the direction indicated by arrow602. As a result, the nut250is disposed in closer proximity to the lower hanger346than the lower hanger344in the staged state600of the park system200. In the illustrative embodiment, the position of the nut250along the axis242in the staged state600substantially corresponds to the position of the nut250along the axis242in the engaged state400.

Due to the operative coupling between the nut250and the sleeve270provided by the lever260, translation of the nut250along the axis242in the direction indicated by arrow602drives translation of the sleeve270along the longitudinal axis282in the direction indicated by arrow604. However, in contrast to each of the engaged and disengaged states400,500of the park system200, movement of the rod280and the collar290along the longitudinal axis282toward the park actuation assembly210is constrained by the latch256in the staged state600. As a result of that constraint, the collar290does not contact the sleeve270in the staged state600and is spaced from the sleeve270along the longitudinal axis282.

In the staged state600of the park system200, the latch solenoid258is extended to drive movement of the latch256to the deployed position658. Contact between the latch256and the collar290in the staged state600resists movement of the rod280and the collar290toward the park actuation assembly210along the longitudinal axis282. In some embodiments, the latch solenoid258is energized, powered on, or activated in the staged state600. In other embodiments, however, the latch solenoid258may be de-energized, powered off, or de-activated in the staged state600of the park system200.

In some embodiments, in an event of an electrical failure in the staged state600of the park system200, the latch256may transition from the deployed position658to the released position456. As a result, the rod280and the collar290may translate along the longitudinal axis282(e.g., from the respective positions associated with the staged state600) in the direction indicated by arrow604such that the collar290contacts the sleeve270. It should be appreciated that the position of the sleeve270in the staged state600of the park system200substantially corresponds to the position of the sleeve270in the disengaged state500.

Referring now toFIG.7, in the illustrative embodiment, the control system700includes the electric actuator220, the latch solenoid258, the sensor368, the controller702, input devices710, and other device(s)720. Each of the devices220,258,368,710,720is communicatively coupled to the controller702, such as by a direct (e.g., hardwired) connection or a controller area network (CAN) interface, for example. Of course, it should be appreciated that the control system700may include other electrical and/or electromechanical devices in addition to, or as an alternative to, the devices depicted inFIG.7. In any case, the illustrative controller702includes a processor704(or one or more processors) and at least one memory device706communicatively coupled to the processor704.

The processor704of the illustrative controller702may be embodied as, or otherwise include, any type of processor, controller, or other compute circuit capable of performing various tasks such as compute functions and/or controlling the functions of the transmission120and/or the park system200, for example. For example, the processor704may be embodied as a single or multi-core processor(s), a microcontroller, or other processor or processing/controlling circuit. In some embodiments, the processor704may be embodied as, include, or otherwise be coupled to an FPGA, an application specific integrated circuit (ASIC), reconfigurable hardware or hardware circuitry, or other specialized hardware to facilitate performance of the functions described herein. Additionally, in some embodiments, the processor704may be embodied as, or otherwise include, a high-power processor, an accelerator co-processor, or a storage controller. In some embodiments still, the processor704may include more than one processor, controller, or compute circuit.

The memory device706of the illustrative controller702may be embodied as any type of volatile (e.g., dynamic random access memory (DRAM), etc.) or non-volatile memory capable of storing data therein. Volatile memory may be embodied as a storage medium that requires power to maintain the state of data stored by the medium. Non-limiting examples of volatile memory may include various types of random access memory (RAM), such as dynamic random access memory (DRAM) or static random access memory (SRAM). One particular type of DRAM that may be used in a memory module is synchronous dynamic random access memory (SDRAM). In particular embodiments, DRAM of a memory component may comply with a standard promulgated by JEDEC, such as JESD79F for DDR SDRAM, JESD79-2F for DDR2 SDRAM, JESD79-3F for DDR3 SDRAM, JESD79-4A for DDR4 SDRAM, JESD209 for Low Power DDR (LPDDR), JESD209-2 for LPDDR2, JESD209-3 for LPDDR3, and JESD209-4 for LPDDR4 (these standards are available at wwwjedec.org). Such standards (and similar standards) may be referred to as DDR-based standards and communication interfaces of the storage devices that implement such standards may be referred to as DDR-based interfaces.

In some embodiments, the memory device706may be embodied as a block addressable memory, such as those based on NAND or NOR technologies. The memory device306may also include future generation nonvolatile devices, such as a three dimensional crosspoint memory device (e.g., Intel 3D XPoint™ memory), or other byte addressable write-in-place nonvolatile memory devices. In some embodiments, the memory device706may be embodied as, or may otherwise include, chalcogenide glass, multi-threshold level NAND flash memory, NOR flash memory, single or multi-level Phase Change Memory (PCM), a resistive memory, nanowire memory, ferroelectric transistor random access memory (FeTRAM), anti-ferroelectric memory, magnetoresistive random access memory (MRAM) memory that incorporates memristor technology, resistive memory including the metal oxide base, the oxygen vacancy base and the conductive bridge Random Access Memory (CB-RAM), or spin transfer torque (STT)-MRAM, a spintronic magnetic junction memory based device, a magnetic tunneling junction (MTJ) based device, a DW (Domain Wall) and SOT (Spin Orbit Transfer) based device, a thyristor based memory device, or a combination of any of the above, or other memory. The memory device may refer to the die itself and/or to a packaged memory product. In some embodiments, 3D crosspoint memory (e.g., Intel 3D XPoint™ memory) may comprise a transistor-less stackable cross point architecture in which memory cells sit at the intersection of word lines and bit lines and are individually addressable and in which bit storage is based on a change in bulk resistance.

In some embodiments, the electric actuator220includes, or is otherwise embodied as, an electric stepper motor or other suitable electric actuator. Additionally, in some embodiments, the electric actuator220includes, or is otherwise embodied as, an actuator having a normally-open or normally-on state. However, in other embodiments, the electric actuator220may include, or otherwise be embodied as, an actuator having a normally-closed state or normally-off state.

In some embodiments, the latch solenoid258includes, or is otherwise embodied as, any electrical device or collection of electrical devices capable of converting electrical energy into mechanical work to drive movement of the latch256between the released position456and the deployed position658. Additionally, in some embodiments, the latch solenoid258includes, or is otherwise embodied as, an actuator having a normally-closed state or normally-off state. However, in other embodiments, the latch solenoid258includes, or is otherwise embodied as, an actuator having a normally-open or normally-on state.

In some embodiments, the sensor368includes, or is otherwise embodied as, any electrical device or collection of electrical devices capable of detecting a position of the collar290along the longitudinal axis282in use of the park system200. Additionally, in some embodiments, the sensor368includes, or is otherwise embodied as, a proximity sensor, such as a capacitive proximity sensor, an inductive proximity sensor, a hall effect sensor, or the like. Of course, in other embodiments, the sensor368may include, or otherwise be embodied as, another suitable sensor.

In the illustrative embodiment, the input devices710include a park input712, a non-park input714, and a staged state input716. Each of the inputs712,714,716is communicatively coupled to the controller702, at least in some embodiments. The park input712includes, or is otherwise embodied as, an input device that may be selected by a user to direct operation of the transmission120and the park system200in a park operating mode corresponding to the engaged state400. The park input714includes, or is otherwise embodied as, an input device that may be selected by a user to direct operation of the transmission120and the park system200in a non-park operation mode (e.g., a drive or neutral mode) corresponding to the disengaged state500. The park input716includes, or is otherwise embodied as, an input device that may be selected by a user to direct operation of the transmission120and the park system200in an operating mode corresponding to the staged state600.

In some embodiments, the other device(s)720include one or more other electrical or electromechanical devices included in the park system200, the transmission120, and/or the drive system100. The device(s)720may be incorporated into, or otherwise associated with, the drive unit102, the torque converter108, the transmission120, the gearing system126, or the electro-hydraulic system138, as the case may be. For example, the device(s)720may include the speed sensors146,148,150, at least in some embodiments. In another example, the device(s)720may include the controller160. Additionally, in some embodiments, the device(s)720may include one or more sensors, controllers, solenoids, solenoid valves, and flow control devices, among other things.

Referring now toFIG.8, an illustrative method800of operating the transmission120may be embodied as, or otherwise include, a set of instructions that are executable by the control system700. The method800corresponds to, or is otherwise associated with, performance of the blocks described below in the illustrative sequence ofFIG.8. It should be appreciated, however, that the method800may be performed in one or more sequences different from the illustrative sequence.

The illustrative method800begins with block802. In block802, the controller702operates the transmission120and the park system200in the engaged state400. As a result, in block802, the controller702resists rotation of the output shaft124using the park actuation assembly210of the system200. In the illustrative embodiment, to perform block802, the controller702performs the method900described below with reference toFIG.9. From block802, the method800proceeds to block804.

In block804of the illustrative method800, the controller702operates the transmission120and the park system200in the disengaged state500. Consequently, in block804, the controller702allows rotation of the output shaft124using the park actuation assembly210of the system200. In the illustrative embodiment, to perform block804, the controller702performs the method1000described below with reference toFIG.10. From block804, the method800proceeds to block806.

In block806of the illustrative method800, the controller702operates the transmission120and the park system200in the staged state600. In doing so, in block806, the controller702transitions the park system200, and/or stages the park system200for a transition, from the staged state600to the engaged state400in the event of an electrical failure or in the event that the controller702receives input to place the transmission120and the park system in the engaged state400. In the illustrative embodiment, to perform block806, the controller702performs the method1100described below with reference toFIG.11.

Referring now toFIG.9, an illustrative method900of operating the transmission120and the park system200in the engaged state400may be embodied as, or otherwise include, a set of instructions that are executable by the control system700. The method900corresponds to, or is otherwise associated with, performance of the blocks described below in the illustrative sequence ofFIG.9. It should be appreciated, however, that the method900may be performed in one or more sequences different from the illustrative sequence.

The illustrative method900begins with block902. In block902, the controller702receives input (e.g., from a user) to operate the transmission120and the park system200in the engaged state400. For example, in block902, the controller702may receive input from the park input712. In other embodiments, the controller702may receive input from another input device indicative of desired operation in the engaged state400. From block902, the method900proceeds to block904.

In block904of the illustrative method900, the controller702issues a control signal to the electric actuator220to drive operation of the park system200in the engaged state400in response to the input received in block902. In some embodiments, performance of block904by the controller702may include verifying or confirming the correct position of the actuator220. In such embodiments, performance of block904may be based on the In the illustrative embodiment, the control signal issued by the controller702in block904directs rotation of the actuator220to cause rotation of the screw240and corresponding translation of the nut250along the longitudinal axis242in the direction indicated by arrow402, as discussed above with reference toFIG.4. From block904, the method900subsequently proceeds to block906.

In block906of the illustrative method900, the controller702issues a control signal to the latch solenoid258to drive disengagement of the latch256from the collar290in response to the input received in block902. As a result of the control signal issued by the controller702in block906, the latch256and the collar290are spaced from one another such that translation of the rod280and the collar290along the longitudinal axis282is not constrained by the latch256. From block906, the method900proceeds to block908.

In block908of the illustrative method900, the controller702measures a position of the collar290along the longitudinal axis282in response to the input received in block902. It should be appreciated that measurement is performed in block908with, and based on, a position of the collar290along the axis282that is detected by the sensor368. In some embodiments, the position measured in block908may provide a diagnostic indicator for evaluating operation of the park system200in the engaged state400in the use of the transmission120.

Referring now toFIG.10, an illustrative method1000of operating the transmission120and the park system200in the disengaged state500may be embodied as, or otherwise include, a set of instructions that are executable by the control system700. The method1000corresponds to, or is otherwise associated with, performance of the blocks described below in the illustrative sequence ofFIG.10. It should be appreciated, however, that the method1000may be performed in one or more sequences different from the illustrative sequence.

The illustrative method1000begins with block1002. In block1002, the controller702receives input (e.g., from a user) to operate the transmission120and the park system200in the disengaged state500. For example, in block1002, the controller702may receive input from the non-park input714. In other embodiments, the controller702may receive input from another input device indicative of desired operation in the disengaged state500. From block1002, the method1000proceeds to block1004.

In block1004of the illustrative method1000, the controller702issues a control signal to the electric actuator220to drive operation of the park system200in the disengaged state500in response to the input received in block1002. In at least some embodiments, the control signal issued by the controller702in block1004is different from, and/or distinct from, the control signal issued by the controller702in block904. In the illustrative embodiment, the control signal issued by the controller702in block1004directs rotation of the actuator220to cause rotation of the screw240and corresponding translation of the nut250along the longitudinal axis242in the direction indicated by arrow506, as discussed above with reference toFIG.5. From block1004, the method1000subsequently proceeds to block1006.

In block1006of the illustrative method1000, the controller702issues a control signal to the latch solenoid258to drive disengagement, and/or confirm disengagement, of the latch256from the collar290in response to the input received in block1002. In some embodiments, due to disengagement of the latch solenoid258in a previous operating state (e.g., a previous park engagement), block1006may include maintaining the previous disengaged state of the latch solenoid258to effect disengagement of the latch256from the collar290. As a result of the control signal issued by the controller702in block1006, the latch256and the collar290are spaced from one another such that translation of the rod280and the collar290along the longitudinal axis282is not constrained by the latch256. In at least some embodiments, the control signal issued by the controller702in block1006is identical, or substantially identical, to the control signal issued by the controller702in block906. From block1006, the method1000proceeds to block1008.

In block1008of the illustrative method1000, the controller702measures a position of the collar290along the longitudinal axis282in response to the input received in block1002. It should be appreciated that measurement is performed in block1008with, and based on, a position of the collar290along the axis282that is detected by the sensor368. In some embodiments, the position measured in block1008may provide a diagnostic indicator for evaluating operation of the park system200in the disengaged state500in the use of the transmission120.

Referring now toFIG.11, an illustrative method1100of operating the transmission120and the park system200in the staged state600may be embodied as, or otherwise include, a set of instructions that are executable by the control system700. The method1100corresponds to, or is otherwise associated with, performance of the blocks described below in the illustrative sequence ofFIG.11. It should be appreciated, however, that the method1100may be performed in one or more sequences different from the illustrative sequence.

The illustrative method1100begins with block1102. In block1102, the controller702receives input (e.g., from a user) to operate the transmission120and the park system200in the staged state600. For example, in block1102, the controller702may receive input from the staged state input716. In other embodiments, the controller702may receive input from another input device indicative of desired operation in the staged state600. From block1102, the method1100proceeds to block1104.

In block1104of the illustrative method1100, the controller702issues a control signal to the latch solenoid258to drive extension thereof and engagement of the latch256with the collar290in response to the input received in block1102. As a result of the control signal issued by the controller702in block1104, the latch256and the collar290are in direct contact such that translation of the rod280and the collar290along the longitudinal axis282is constrained by the latch256, as discussed above with reference toFIG.6. In at least some embodiments, the control signal issued by the controller702in block1104is different from, and/or distinct from, each of the control signals issued by the controller702in blocks906and1006. From block1104, the method1100proceeds to block1106.

In block1106of the illustrative method1100, the controller702issues a control signal to the electric actuator220to drive operation of the park system200in the staged state600in response to the input received in block1102. In at least some embodiments, the control signal issued by the controller702in block1106is different from, and/or distinct from, each of the control signals issued by the controller702in blocks904and1004. In the illustrative embodiment, the control signal issued by the controller702in block1106directs rotation of the screw240and corresponding translation of the nut250along the longitudinal axis242in the direction indicated by arrow602, as discussed above with reference toFIG.6. From block1106, the method1100subsequently proceeds to block1108.

In block1108of the illustrative method1100, the controller702measures a position of the collar290along the longitudinal axis282in response to the input received in block1102. It should be appreciated that measurement is performed in block1108with, and based on, a position of the collar290along the axis282that is detected by the sensor368. In some embodiments, the position measured in block1108may provide a diagnostic indicator for evaluating operation of the park system200in the staged state600in the use of the transmission120.

While the disclosure has been illustrated and described in detail in the foregoing drawings and description, the same is to be considered as exemplary and not restrictive in character, it being understood that only illustrative embodiments thereof have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.