Patent Description:
Generally, gear assembly actuation is done manually or with the assistance of an actuator. However, most examples have separate actuation assemblies from the fork. In actuators utilizing separate actuation assemblies and forks, the integration of the separate components into a gearbox is complex and application specific, presenting the challenge of utilizing one actuator assembly into several applications.

<CIT> discloses a shift actuator according to the preamble of claim <NUM>.

Typically, the actuation member is configured to linearly move a fork connected with a dog clutch between a plurality of positions. The actuator assembly is operated with a manual force (e.g. a standard gearbox where a user selects gears by moving an actuator from position to position) or with an actuator to move a fork connected with a dog clutch between positions. Given the nature of some gear actuation, when a sliding gear is being moved from a disengaged position into engaged with a receiving gear, there is a momentary blockage or misalignment of gear teeth on the sliding gear and the gear teeth on the receiving gear. In this moment of misalignment, the shift fork is pressing the sliding gear against the receiving gear but the sliding gear is not entering the receiving gear, generating resistance against the fork since the sliding gear teeth and the receiving gear teeth are not aligned. The time window for engagement is typically short due to gear assembly design. If time window is not utilized, a stronger motor is required as force becomes higher to force the teeth of the sliding gear into alignment with the teeth of the receiving gear. This uses a larger force and operates slower, which may not seat the sliding gear into the receiving gear as far, and/or cause premature wear and damage on the system.

It would be attractive to have an actuator which is low cost with a simple integration into several different systems and types on gearboxes. It would be attractive to have an actuator which provided fast shifts with low force and high acceleration, preventing damage and premature wear. It would be attractive to have an actuator with an integrated fork and actuator.

The present teachings solve one or more of the present needs by providing an actuator with low cost, simple integration into a variety of applications, and fast actuation between positions while applying a low force with exceptional penetration.

The present teachings provide for an actuator including a support; a drive system connected to the support; a shift fork operatively connected to the drive system and configured to move a distance defining a stroke length between a disengaged position and an engaged position, the shift fork having a cam follower; a cam assembly operatively connected with the drive system to move between a neutral position, and a shifted position, with a plurality of intermediate positions between the neutral and shifted positions, the shift fork being in the disengaged position when the cam assembly is in the neutral position, the cam assembly including: a cam having an aperture defining an interior surface; a hub housing disposed within the aperture of the cam and connected to the drive system; and a biasing member disposed within the aperture and preloaded between an interior surface of the aperture of the cam and the hub housing. When the cam moves relative to the hub housing, the biasing member compressing between the hub housing and interior surface of the cam when the cam assembly is rotated through the plurality of intermediate positions and the shift fork remains in the disengaged position due to an interference. The cam moves relative to the hub housing with the biasing member expanding to push the cam against the shift fork such the shift fork moves through the stroke length from the disengaged position to the engaged position upon clearance of the interference.

The present teachings relate to an actuator <NUM> (also referred to as the actuator system). The actuator system <NUM> includes an actuation assembly <NUM> that functions to move a shift fork adapted to connect with a dog clutch <NUM> between a disengaged position <NUM> and one or more engaged positions <NUM>. The actuator system <NUM> includes a cam assembly <NUM>. The actuator system <NUM> may be connected with a controller. The controller may function to selectively disengage and engage the actuator system <NUM> by signaling the cam assembly <NUM> to interact with the shift fork <NUM>, moving the shift fork <NUM> between positions. The actuator <NUM> may be attached to a transmission, a transfer case, an axle, a gearbox, a controller, the like, or a combination thereof. The actuator <NUM> may be used in automobiles, autonomous vehicles, robots, trucks, marine vessels, or any other vehicle or machine that utilizes moving gears. The actuator system <NUM> may be used on any device that couples two rotating shafts, gears, or other rotating components. For example, the actuator system <NUM> is adapted to move a dog clutch <NUM> in and out of engagement with a receiving gear <NUM>. The actuator system <NUM> may be used in conjunction with multiple actuator systems. For example, a transmission may have a first actuator system <NUM> which actuates a first gear and a second gear, and a second actuator system <NUM> which actuates a third gear and a fourth gear. It is contemplated that each actuator system <NUM> may move a dog clutch <NUM> into communication with one or more receiving gears <NUM>.

The actuator system <NUM> is shown in <FIG> and <FIG> in a perspective view. The actuator system <NUM> includes a base or a support <NUM> and a housing or a cover <NUM>. The support <NUM> and the cover <NUM> form a cavity therebetween. The housing has a relatively low profile, minimizing the amount of space needed to house the actuation assembly <NUM>. The shift fork <NUM> extends from through the support <NUM>, configured to slide inside of a gearbox and operatively couple with a dog clutch <NUM>. The shift fork <NUM> is pivotally coupled with the support <NUM>. The actuator system <NUM> is configured to mount to the surface <NUM> of a gearbox <NUM>, which is shown in <FIG> and partially shown in <FIG>.

The support <NUM> includes at least one pair of lugs <NUM>, each lug extending away from the support <NUM>, having an opening extending from the cavity formed between the support <NUM> and the cover <NUM>. Each of the lugs <NUM> has an opening and an outer surface. The lugs each form a passage from the inner portion of the cavity. The lugs <NUM> each have a shape to allow the shift fork <NUM> to move between the neutral position and shifted position. The lugs <NUM> assist in mounting the actuator system <NUM> to the outer surface <NUM> of a gearbox <NUM>. Each lug <NUM> is axially disposed around a portion of the shift fork <NUM> and may connect with and provide a pivot point <NUM> to the shift fork <NUM>, described further below.

As seen in <FIG>, the gearbox <NUM> includes at least one pair of apertures <NUM> in the surface <NUM> to allow at least a portion of the actuator system <NUM> and the shift fork <NUM> to pass into the gearbox <NUM>. The holes on the gearbox are small in order to maintain structural rigidity and strength. Similarly, the shift fork <NUM> is sized to pass through the apertures <NUM> on the surface <NUM> of the gearbox <NUM>. The shift fork <NUM> is shown below a partial view of the gearbox surface <NUM> in schematic <FIG> and <FIG>, while the remainder of the actuator system <NUM> is above the surface <NUM> of the gearbox <NUM>. <FIG> illustrates a perspective view of a gearbox <NUM> showing the pair of apertures <NUM> as bosses extending from the outer surface <NUM> of the gearbox. In some examples, the gearbox <NUM> includes a gear assembly <NUM>, configured as a dog clutch assembly, which is illustrated in <FIG> and <FIG>. The apertures <NUM> located on the outer surface <NUM> of the gearbox <NUM> provide passages to receive the shift fork <NUM> and at least a portion of the support <NUM>.

<FIG> show the actuator system <NUM> connecting with the gearbox <NUM>. <FIG> depicts at least one shift fork <NUM> of the actuator system <NUM> aligned with the apertures <NUM>. The lugs <NUM> and the apertures <NUM> have complimentary shapes, the apertures <NUM> sized larger than the lugs <NUM> in order to receive the lugs <NUM>. The apertures <NUM> include a sealing surface <NUM> for mating with the seal <NUM> located around each lug <NUM> and on the bottom surface of the support <NUM>.

<FIG> and <FIG> are partial cross-sectional views of the actuator system <NUM> and the gearbox <NUM>. <FIG> shows a partial longitudinal cross-section of the actuator system <NUM> and the gearbox <NUM>. Similarly, <FIG> shows a partial lateral cross-section of the actuator <NUM> and the gearbox <NUM>. The actuator system <NUM> passes at least a portion of the shift fork <NUM> and the lugs <NUM> through the outer surface <NUM> of the gearbox <NUM> to connect the shift fork <NUM> with the gear assembly <NUM> (shown in <FIG> and <FIG>). The lug <NUM> and the pivot <NUM> can be seen in <FIG> and <FIG> disposed below the surface <NUM> of the gearbox <NUM>. When connected, as shown in <FIG>, the shift fork <NUM> engages the dog clutch <NUM> (also referred to as slider gear) to move the dog clutch <NUM> through positions <NUM>, <NUM>, <NUM> into and out of engagement with receiving gear(s) <NUM>.

<FIG> shows the partial lateral cross-sectional view of the actuator system <NUM> and the gearbox <NUM>, with the actuator system <NUM> connected with the gear assembly <NUM>. As explained further below, the cam assembly <NUM> and actuation assembly <NUM> work to move the dog clutch <NUM> between positions <NUM>, <NUM>, <NUM> by pivoting shift fork <NUM> between positions. <FIG> illustrates the pair of arms of the shift fork <NUM> each disposed within one of the pair of lugs <NUM>, each arm pivotally connected <NUM> to a corresponding lug of the pair of lugs <NUM>. The arms of the shift fork <NUM> are spaced apart corresponding to the size of the dog clutch <NUM>. <FIG> is a close-up lateral view of a lug <NUM> retained within the aperture <NUM> with the pivot <NUM> below at least a portion of the outer surface <NUM> of the gearbox <NUM>. In some examples, the pivot connection <NUM> is below the outer surface <NUM> of the gearbox <NUM>.

Turning to <FIG>, the actuator system <NUM> includes a cam assembly <NUM>. The cam assembly <NUM> functions to actuate the shift fork <NUM> between positions. The cam assembly <NUM> is configured to move between a neutral position, an intermediate position, and a shifted position, moving the shift fork from the disengaged position <NUM> to the engaged position <NUM>. The cam assembly <NUM> is configured to transition to and from the neutral position and the shifted position through a plurality of intermediate positions, however, for purposes of this application "intermediate position" encompasses the plurality of possible positions between the neutral position and the shifted position. The shifted position of the cam assembly <NUM> corresponds with the engaged position <NUM> of the shift fork <NUM>, and the neutral position corresponds with the disengaged position <NUM> of the shift fork <NUM>. The cam assembly <NUM> connects with the gear set <NUM> through an output <NUM>. The output <NUM> has any suitable size or shape to connect the gear set <NUM> with the cam assembly <NUM>. For example, the output <NUM> may be a shaft, an axle, a coupler, or the like, which is received by the cam assembly <NUM>. The cam assembly <NUM> functions to transition the shift fork <NUM> through various positions when a signal from a controller (not pictured) is sent to the motor <NUM> to rotate the gear set <NUM> connected to the cam <NUM>, rotating the cam <NUM> and contacting the cam follower <NUM> to pivot the actuator bracket <NUM> and the shift fork <NUM> between the disengaged position <NUM> and the engaged position <NUM>. The cam assembly <NUM> may have one or more bosses to receive one or more bearings <NUM>. The bearings <NUM> function to constrain the movement of the cam assembly <NUM> to rotation, and to transfer radial force from the cam <NUM> to the support <NUM>.

The actuator system <NUM> includes a drive system comprising a motor <NUM>, a gear set <NUM>, and an output <NUM>. The motor <NUM> functions to rotate a gear set <NUM> which in-turn rotates the output <NUM>, turning the cam assembly <NUM>. The motor <NUM> functions to receive a signal from a controller to rotate clockwise or counterclockwise depending on the pivotal movement required to move the shift fork <NUM> between positions <NUM>, <NUM>. Similar to the movement of the cam assembly <NUM>, the shift fork <NUM> moves to and from the disengaged position <NUM> and the engaged position <NUM> through a plurality of intermediate positions <NUM>, however, for purposes of this application "intermediate position" encompasses the plurality of possible positions between the disengaged position <NUM> and the engaged position <NUM>. The motor is mounted to the support <NUM>. The motor <NUM>, as shown in the figures, is an electric motor, however, any suitable means for actuating the cam assembly <NUM> is contemplated, such as a pneumatic actuator, hydraulic actuator, a manual actuation, or the like. The motor <NUM> rotates gear set <NUM> which rotates the cam assembly <NUM>.

As best seen in <FIG>, and <FIG>, the actuator system <NUM> includes a gear set <NUM>. The gear set <NUM> functions to amplify torque generated by the motor <NUM> to increase the rotational torque of the cam <NUM>. The motor <NUM> rotates the gear set <NUM>, turning the cam assembly <NUM>. The gear set <NUM> rotates the cam <NUM> with a greater torque than the amount of torque produced by the motor <NUM>, actuating the shift fork <NUM> between positions <NUM>, <NUM>, <NUM> with greater torque and force, at a lower angular velocity. The gear set <NUM> may be a planetary gear arrangement which amplifies torque to increase the force which the cam <NUM> applies against the cam follower <NUM>.

The actuator system <NUM> includes an actuation assembly <NUM> in communication with the cam assembly <NUM>. The actuation assembly <NUM> functions to be moved by the cam assembly <NUM> to pivot and move the shift fork <NUM> between positions <NUM>, <NUM>, <NUM> (<FIG>). The actuation assembly <NUM> at least includes a shift fork <NUM>, one or more pivot couplers <NUM> connecting the shift fork <NUM> to the support <NUM>. The shift fork <NUM> may include one or more cam followers <NUM> and an actuator bracket <NUM> configured to hold and position the one or more cam followers <NUM>.

The cam follower <NUM> functions to contact the cam <NUM> as the cam <NUM> is rotated. The cam follower <NUM> functions to convert the contacting force of the cam <NUM> into pivotal movement of the shift fork <NUM>. In the examples, such as shown in <FIG>, the cam follower <NUM> is attached to an actuator bracket <NUM> disposed around the axis of the cam <NUM> so that the follower portion <NUM> of the cam <NUM> is positioned to contact the cam follower <NUM> during rotation (<FIG>). The actuator bracket <NUM> is directly connected with the shift fork <NUM>, so that as the cam follower <NUM> is contacted, the actuator bracket <NUM> is moved by the cam <NUM> and the shift fork <NUM> is pivoted.

The actuator bracket <NUM> functions to hold the one or more cam followers <NUM>. The actuator bracket <NUM> functions to convert the rotational force of the cam <NUM> into pivotal movement of the shift fork <NUM> about the pivot axis PA, pushing the dog clutch <NUM> linearly. As mentioned above, the actuator bracket <NUM> may be a portion of the shift fork <NUM>. The actuator bracket may have a c-shape or u-shape. In the example shown in <FIG>, the actuator bracket <NUM> has a c-shape, so that when the one or more cam followers <NUM> are struck by the cam, the shift fork <NUM> pivots. The actuator bracket <NUM> may be formed with an opening, a pocket, a detent, or similar feature to allow the cam <NUM> to rotate through. The actuator bracket <NUM>, as seen in <FIG> and <FIG>, may include a pocket configured to allow the cam <NUM> to rotate between the cam followers <NUM>.

Turning to <FIG>, the shift fork <NUM> functions to pivot between a plurality of positions and is configured to move a dog clutch <NUM> between the plurality of positions, particularly into and out of engagement with one or more receiving gears <NUM>. The shift fork <NUM> may have a general u-shape or c-shape, comprising a top surface and two arms disposed perpendicularly from the surface, reaching towards and engaging the dog clutch <NUM>. In some examples, the actuator system <NUM> may include more than one shift fork <NUM>. The shift fork <NUM> may include pads <NUM>. The pads <NUM> may be located at the distal end of the shift fork <NUM> arms and configured to engage a dog clutch <NUM> (seen in <FIG>). The cam follower <NUM> and the actuator bracket <NUM> may be integral with the shift fork <NUM>. The shift fork <NUM> is connected with the pivot coupler <NUM> (<FIG>). The shift fork <NUM> is pivotally coupled with the support <NUM> through the pivot coupler <NUM>. A perspective view of one example of a shift fork can be seen in <FIG>.

The cam assembly <NUM> includes a cam <NUM>. The cam <NUM> functions to actuate the cam follower <NUM>, the actuator bracket <NUM>, and the shift fork <NUM>. The cam <NUM> has a base circle <NUM> disposed around a rotational center of the cam <NUM> which rotates about a rotation axis RA and a follower portion <NUM> designed to interact with the cam follower <NUM> attached with the actuator bracket <NUM> to move the shift fork <NUM> between positions <NUM>, <NUM>, <NUM>. The cam <NUM> may have a generally eccentric shape with a rounded outer surface corresponding with the profile of the cam <NUM>. The cam <NUM> includes a base circle <NUM> and a follower portion <NUM>. The follower portion <NUM> extends from the base circle <NUM> of the cam <NUM> and has a modified egg-like shape used to transition move the shift fork <NUM> between positions. The follower portion <NUM> includes a first section <NUM> including a pair of circular sections <NUM> having a first radius located on opposite sides of the cam <NUM>, and a second section <NUM> having a distal tip <NUM> including a second circular portion with a wider radius than the circular sections <NUM> of the first section <NUM>. The profile of the cam <NUM> is wide at the first section <NUM> and tapers to the second section <NUM>. The profile of both the first section <NUM> and second section <NUM> have a rounded contact surface for contacting the cam follower <NUM>. The circular sections of the first section <NUM> may be configured as concentric circles. As mentioned above, the radius of the distal tip <NUM> of the cam <NUM> may have a wider radius than the circular protrusions of the first section <NUM>.

The circular sections <NUM> of the first portion <NUM> and the circular section <NUM> of the second portion <NUM> each correspond with a concentric circle <NUM>, <NUM>, <NUM> relative to the rotational center point of the cam <NUM>. <FIG> depict a schematic view of the actuator system <NUM> with the concentric circles corresponding to the base circle <NUM>, the first concentric circle <NUM> associated with the first circular sections <NUM>, and a second concentric circle <NUM> corresponding with the distal tip <NUM>. When two of the circular sections of the cam <NUM>, <NUM>, <NUM> are touching the cam followers <NUM>, the cam assembly <NUM> and the drive system may be prevented from being backdriven by force transferred though the shift fork <NUM>. When two of the circular sections <NUM>, <NUM>, <NUM> are contacting the cam followers <NUM>, any torque applied through the shift fork <NUM> is directed towards the rotational center of the cam assembly <NUM> resulting in no rotational force onto the cam assembly <NUM>.

The cam <NUM> is configured to radially move relative to the rotation axis, changing the position of the cam <NUM> relative to the rotational axis (explained further below). The cam <NUM> is configured to contact and move the cam follower <NUM> and actuator bracket <NUM> a specific distance, pivoting the shift fork <NUM> between positions <NUM>, <NUM>, <NUM>, moving the dog clutch <NUM> into or out of contact with the receiving gear <NUM>. The cam <NUM> is connected with and rotated by the gear set <NUM>. The cam <NUM> includes one or more biasing member cam mounts <NUM> to receive one or more biasing members <NUM>.

The biasing members <NUM> functions to assist the actuation assembly <NUM> in rapidly moving the actuation assembly <NUM> between the disengaged position <NUM> and the engaged position <NUM>. The biasing members <NUM> functions to assist the shift fork <NUM> in overcoming a momentary blockage condition by storing potential energy in the biasing members <NUM> when compressed and releasing that energy as a force onto the cam follower <NUM> and the shift fork <NUM> (<FIG>). The one or more biasing members <NUM> is part of the hub assembly <NUM> described further below. In some examples, the biasing members <NUM> are pre-loaded into the hub assembly <NUM>, as seen in <FIG>. The biasing members <NUM> may be configured to have a length in an expanded state configured to push the shift fork <NUM> through a full stroke via the cam assembly <NUM>. The pre-loaded biasing members <NUM> may be slightly compressed. Throughout the present application "expanded" refers to the biasing members <NUM> in a state of substantial expansion, encompassing the slight compression of a preload. In some examples, the preloaded biasing members may generate <NUM> or more newtons, <NUM> or more newtons, <NUM> or more newtons, or even <NUM> or more newtons of force. In other examples, the preloaded biasing members may generate greater force or lesser force depending on the application of the actuator system <NUM>. The one or more biasing members <NUM> are configured to generate substantial force to assist in the alignment and engagement of a dog clutch <NUM> with a receiving gear <NUM>. In some examples, such as seen in <FIG>, the biasing members, when compressed, may produce a force of <NUM> or more newtons, <NUM> or more newtons, or even <NUM> or more newtons of force. In other examples, the biasing members <NUM> may be scaled up or down in force to fit the application such (i.e. more force for a marine vessel propulsion system and less force for a watch mechanism). The biasing members <NUM> are configured to have an expanded length that corresponds with the distance the shift fork must move to transition between the disengaged position <NUM> and the engaged position <NUM>. For example, in some passenger car applications, the biasing members <NUM> may have an expanded length of <NUM> or more, <NUM> or more, or even <NUM> or more, corresponding with the length the shift fork must move a gear between positions. In other examples, the expanded length of the biasing members may be longer or shorter depending on the application of the actuator system <NUM>. The length of biasing members <NUM> corresponds with the application based on the length of the stroke the shift fork <NUM> moves between positions <NUM>, <NUM>. The one or more biasing members <NUM> provide a persistent application force applied through the cam <NUM> during rotation onto the cam follower <NUM>. As the cam <NUM> turns, the pressure steadily persists as the cam <NUM> is rotated, applying pressure corresponding to the exterior profile of the cam <NUM> contacting the cam follower <NUM> and the compression of the biasing members <NUM> when there is a blockage condition.

As the cam <NUM> is rotated, the contact between the cam profile and the cam follower <NUM> can be measured as a pressure angle. When the cam <NUM> is rotated and the profile of the cam (between the first section <NUM> and the second section <NUM> of the follower portion <NUM>) transitions, contacting the cam follower <NUM>, the pressure angle is greater than zero. As the cam <NUM> is rotated to move the shift fork <NUM> from position to position <NUM>, <NUM>, <NUM>, a distance between the cam follower <NUM> and the rotational axis RA changes along the contact surface of the cam profile as the cam <NUM> rotates and interacts with the cam follower <NUM>. For example, the radius of the cam <NUM> is the shortest when cam <NUM> is contacting the follower <NUM> at the first section <NUM> moving from the disengaged position <NUM> towards the engaged position <NUM> through a plurality of intermediate positions <NUM>. As the cam <NUM> is rotated, changing the contacting portion of the cam <NUM> from the first section <NUM> towards the second section <NUM>, the radius from the base circle <NUM> and the rotational axis RA is increased, and the pressure angle is decreased. As the cam <NUM> is rotated, the pressure angle changes, applying a consistent force through a combination of the profile of the cam <NUM> and the biasing members <NUM>. The pressure angle of the force applied onto the cam follower <NUM> from the distal tip of cam <NUM> decreases to zero as second section <NUM> of the follower portion <NUM> is rotated to a position relatively perpendicular to the biasing members <NUM> (<FIG>). When the biasing members <NUM> are compressed and generally perpendicular with the cam follower <NUM>, the pressure angle is the smallest, the cam <NUM> is using the full radius of the follower portion <NUM> to transfer force from the biasing members <NUM> through the cam <NUM> onto the cam follower <NUM> through to the shift fork <NUM>. The cam <NUM> may carrier one or more, two or more, three or more, four or more, or even a plurality of biasing members <NUM>. The one or more biasing members <NUM> may be any device with elastic properties where the ratio of load to deflection or displacement is substantially a constant. For example, the one or more biasing members <NUM> are coil springs.

The cam assembly <NUM> includes a hub assembly <NUM>. The hub assembly <NUM> functions to assist the actuator system <NUM> in moving the dog clutch <NUM> into the receiving gear <NUM> when a blockage condition is present. The hub assembly <NUM> functions to move the cam <NUM> between an expanded state <NUM> and a compressed <NUM>, depending on the force exerted onto the follower portion <NUM> of the cam <NUM>. The hub assembly <NUM> includes a hub housing <NUM> that extends through an aperture <NUM> of the cam <NUM>, one or more biasing members <NUM> disposed within the cam aperture <NUM> against an interior surface <NUM> of the cam aperture <NUM> and in communication with the hub housing <NUM>, and a retainer plate <NUM>. The hub assembly <NUM> is connected with the gear set <NUM> so that the hub assembly <NUM> rotates when the motor <NUM> is actuated.

<FIG> and <FIG> illustrate the hub assembly <NUM> including the cam <NUM>. The hub housing <NUM> is connected to gear set <NUM>. The hub housing <NUM> is configured to fit within the aperture <NUM> of the cam <NUM> and is keyed to the aperture <NUM> so that when the gear set <NUM> is turned, the hub housing <NUM> causes the cam <NUM> to turn. The hub housing <NUM> abuts the cam <NUM> along contact surfaces <NUM>, <NUM>, providing an axial stop for the cam <NUM> against the hub housing <NUM>. Similarly, the retainer plate <NUM> is configured to hold the cam <NUM> and hub housing <NUM> in a desired axial relationship. As best seen in <FIG> and <FIG>, the hub housing <NUM> and an interior surface <NUM> of the aperture <NUM> are configured to receive the one or more biasing members <NUM>. The one or more biasing members <NUM> are positioned within the hub housing <NUM> at biasing member mounts <NUM> so that the biasing members <NUM> are pre-loaded between the hub housing <NUM> and the biasing member cam mounts <NUM> of the interior surface <NUM> of the aperture <NUM>. In one example, such as shown in <FIG>, the biasing members <NUM> are disposed within hub mounts <NUM> configured as channels to accept the biasing members <NUM>. As can be seen in <FIG>, the hub housing <NUM> is disposed through the aperture <NUM> of the cam <NUM> and configured to allow the cam <NUM> to be displaced radially along the hub housing <NUM> when the rotational center of the cam <NUM> is moved radially away from the rotational axis RA, compressing the one or more biasing members <NUM> which in turn applies a force onto the follower portion <NUM> of the cam <NUM> to move the shift fork <NUM> and cam assembly <NUM> from one of the plurality of intermediate positions <NUM> to an engaged position <NUM> (corresponding to the shifted position of the cam assembly <NUM>). The cam assembly <NUM> is transitioned from the neutral position and the shifted position through the plurality of intermediate positions <NUM>. As can be seen in <FIG>, the hub assembly <NUM> is shown in an expanded state <NUM>, with the cam <NUM> in an expanded relative to the hub housing <NUM>. When the biasing members <NUM> are compressed, such as in the intermediate position <NUM>, the cam assembly <NUM> is in the compressed state <NUM>. The hub assembly <NUM> is shown in the compressed state in <FIG>, illustrating that the cam <NUM> has moved along the hub housing <NUM> compressing the biasing members <NUM>. The one or more biasing members <NUM> are compressed between the hub and cam mounts <NUM>, <NUM> when a blockage condition is present as the cam <NUM> is rotated, such as seen in <FIG>. The cam <NUM> may turn several degrees before the one or more biasing members <NUM> begin to compress from the resistive force of a blockage condition. In some examples, the cam may turn about <NUM> to <NUM> degrees before the one or more biasing members <NUM> begin to compress.

The hub assembly <NUM> functions to assist the shift fork <NUM> transition between positions <NUM>, <NUM>, and <NUM>, moving the cam <NUM> between a neutral position corresponding to the disengaged position <NUM>, an intermediate position corresponding with the intermediate position <NUM>, and a shifted position corresponding to the engaged position <NUM>. When there is a dog clutch <NUM> misalignment causing a blockage condition, the hub assembly <NUM> applies a force F against the shift fork <NUM> (<FIG>). As can be seen in 21A-21C, the cam assembly <NUM> and hub assembly <NUM> work in conjunction with the actuation assembly <NUM> so that when a blockage condition is present and a resistive force <NUM> is applied to the distal end of the shift fork <NUM>, the hub assembly <NUM> translates the force through the shift fork <NUM> to the cam <NUM>, compressing the one or more biasing members <NUM> between the follower portion <NUM> of the cam <NUM> and the hub housing <NUM> (<FIG>). The compressed biasing members <NUM> apply a force that is great enough to quickly move the dog clutch <NUM> into position when the receiving gear <NUM> and dog clutch <NUM> are aligned. As noted above, the biasing members <NUM> are configured with a length long enough to push the cam assembly <NUM> and actuation assembly <NUM> through the entire stroke of the shift fork <NUM>.

<FIG> and <FIG> illustrate the actuation system <NUM> in a disengaged position <NUM>. The actuator system <NUM> is in the disengaged position <NUM> when the shifter fork <NUM> is in the disengaged position <NUM> (corresponding to the neutral position) and the cam assembly <NUM> is in the neutral position. The circular sections <NUM> are contacting the cam followers <NUM> on both sides of the cam <NUM>. From the disengaged position <NUM>, the shift fork <NUM> may be moved to either side, depending on the rotational direction of the cam <NUM>. For example, the distal end of the shift fork <NUM> is moved to the right when the cam <NUM> contacts the cam follower <NUM> on the left side. The hub assembly <NUM> is shown in the expanded state <NUM>, where the one or more biasing members <NUM> are expanded.

<FIG> and <FIG> illustrate the actuator system <NUM> in an intermediate position <NUM>. The intermediate position <NUM> occurs when a blockage condition, such as when there is a misalignment between the dog clutch <NUM> and the receiving gear <NUM>. During a blockage, a resistive force <NUM> is applied to the distal end of the shift fork <NUM> when the actuator is moving between the disengaged position <NUM> and the engaged position <NUM>. The blockage is caused by a momentary misalignment of the dog clutch <NUM> with the receiving gear <NUM>, so during this misalignment, the shift fork <NUM> is pressing against dog clutch <NUM> which is pressing against the receiving gear <NUM>. The force <NUM> is translated through the shift fork <NUM> and cam assembly <NUM>, loading a force onto the follower portion <NUM> of the cam <NUM> as the cam <NUM> is rotated. The loaded force (created by the compression of the biasing members <NUM>) is in the opposite direction of the blockage force <NUM> exerted on the cam assembly <NUM>. When the cam <NUM> is rotated and the blockage persists, the cam slides radially on the hub, compressing the one or more biasing members <NUM>, storing potential energy, placing the cam assembly <NUM> in an intermediate position. In some examples, such as shown in <FIG> and <FIG>, the base circle <NUM> and first section <NUM> of the cam <NUM> is free from contacting the cam followers <NUM> when the biasing members <NUM> are compressed in the intermediate position <NUM>, moving the rotational center of the cam away from the rotational axis RA. The stored energy is applied from the follower portion of the cam <NUM> onto the cam follower <NUM> and shift fork <NUM>. When the momentary misalignment/blockage is cleared, the stored energy released and translated into a movement force, pushing the shift fork <NUM> through the stroke into the desired position and moving the actuator system <NUM> into the engaged position <NUM> and the cam assembly <NUM> into the shifted position (see <FIG>). The intermediate position <NUM> is present going to and from engaged position <NUM> and the disengaged position <NUM> in either direction. Once in the engaged position, the biasing members <NUM> are expanded and are free from exerting force onto the shift fork <NUM> since the cam <NUM> is contacting both cam followers <NUM> at circular sections <NUM>, <NUM> of the cam <NUM>.

<FIG> and <FIG> illustrate the intermediate position <NUM>. In the intermediate position <NUM>, the shift fork is still relatively at a center position, however, there is a force being applied by the cam <NUM> onto the shift fork <NUM> through the cam follower <NUM> and actuator bracket <NUM>. The hub assembly <NUM> is in the compressed state <NUM>, where the one or more biasing members <NUM> are compressed, placing the cam assembly in the intermediate position. The force is generated by the cam <NUM> contacting the cam follower <NUM>. As displayed in <FIG>, the biasing member <NUM> is being compressed by the rotation of the cam <NUM> and the force <NUM> generated by the misalignment of a dog clutch <NUM> and receiving gear <NUM>. As the cam <NUM> is turned, the follower portion <NUM> of the cam <NUM> begins to apply force against the cam follower <NUM>, compressing the one or more biasing members <NUM>, applying a movement force F. As the distal tip <NUM> of the follower portion <NUM> is moved toward the cam follower <NUM>, the force which is applied to the cam follower <NUM> is consistently applied as the pressure angle is changed. As the cam <NUM> is turned, the hub assembly <NUM> compresses the biasing members <NUM>, moving the rotational center point of the cam <NUM> away from the rotational axis RA, maintaining the contact area of the cam <NUM> onto the follower <NUM> and increasing the alignment force from the follower section <NUM> to the follower <NUM>. When the tip of the follower section <NUM> is contacting the cam follower <NUM>, the biasing members <NUM> of the hub assembly <NUM> are at their most compressed state, applying substantial force onto the follower <NUM> and actuator bracket <NUM> which is multiplied by the length of the actuator bracket <NUM> and shift fork <NUM> to produce a torque. The force generated by the hub assembly <NUM> onto the cam follower <NUM> and subsequently the actuator bracket <NUM> and shift fork <NUM> is used to assist the transitions from disengaged to engaged.

<FIG> and <FIG> illustrate the actuator system <NUM> in an engaged position <NUM>. The actuator system <NUM> is moved into the engaged position <NUM> when the cam follower <NUM> is actuated by the cam <NUM>, the cam follower <NUM> applies a pressure to the top of the shift fork <NUM> through the actuator bracket <NUM>, moving the proximal end of the shift fork <NUM> in the direction of the force which simultaneously moves the distal end of the shift fork <NUM> opposite the direction of the force relative to the pivot axis PA at the pivot coupler <NUM>. The shift fork <NUM> is moved into the engaged position <NUM>. Similarly, when the actuator system <NUM> is moved from the engaged position <NUM> back to the disengaged position <NUM>, the cam <NUM> actuates the cam follower <NUM> on the opposite of the engagement position, moving the actuator bracket <NUM> and shift fork <NUM> from the engaged position <NUM> to the disengaged position in the absence of a momentary blockage condition. As can be seen in <FIG> and 22A-22C, in some examples, the rotational axis RA and the pivot axis PA are arranged in a plane of symmetry, aligning the rotational axis RA and the pivot axis PA in a parallel relationship intersecting the same vertical axis. In other configurations, the rotational axis RA and the pivot axis PA may be offset from one another. Once the cam <NUM> has moved the shift fork <NUM> into the engaged position <NUM>, the profile of the cam <NUM> is configured to prevent a potential back-driving of the actuator <NUM>. The base circle <NUM> and the concentric circular sections <NUM>, <NUM> of the cam <NUM> are shaped to prevent the actuator system <NUM> from being backdriven when the cam assembly <NUM> is in the neutral and shifted positions. Once the cam <NUM> is in the engaged position <NUM>, the cam <NUM> is positioned between the followers <NUM> such that any force applied to the shift fork may not rotate the cam <NUM> due to the position of the cam <NUM> positioned within the actuator bracket <NUM> relative to the cam followers <NUM>. In one example, the distal tip <NUM> of the cam <NUM> is touching one of the cam followers <NUM> and the base circle <NUM> is touching the other cam follower <NUM> such that any force applied by the shift fork <NUM> through the actuator bracket <NUM> and cam followers <NUM> will be directed to the rotational center of the cam <NUM>, preventing the cam from rotating due to the force exerted. <FIG> and <FIG> show the cam surface at both the base circle <NUM> and distal tip <NUM> of the second section <NUM> are contacting both of the cam followers <NUM> such that any force applied through the shift fork <NUM> onto the cam <NUM> will not substantially rotate the cam assembly <NUM> and/or back drive the motor <NUM> because the contact force is directed to the rotational center along the rotational axis RA. Similarly, in the disengaged position <NUM>, the cam profile of the follower portion <NUM> at the first section <NUM> is positioned in the actuator bracket <NUM> relative to the cam followers <NUM> such that the first section <NUM> is contacting both cam followers, directing the contact force to the rotational center about the rotational axis RA, such that the shift fork <NUM> is unable to exert torque onto the cam assembly <NUM>. Further, the hub assembly <NUM> is designed to only allow the cam to slide along the hub housing <NUM> in one direction in order to compress the one or more biasing members <NUM>.

Claim 1:
An actuator system (<NUM>) comprising:
a support (<NUM>);
a drive system connected to the support;
a shift fork (<NUM>) operatively connected to the drive system and configured to move a distance defining a stroke length between a disengaged position and an engaged position, the shift fork (<NUM>) having a cam follower;
a cam assembly (<NUM>) operatively connected with the drive system to move between a neutral position, and a shifted position, with a plurality of intermediate positions between the neutral and shifted positions, the shift fork being in the disengaged position when the cam assembly is in the neutral position, the cam assembly including:
a cam (<NUM>) having an aperture (<NUM>) defining an interior surface (<NUM>);
a hub housing (<NUM>) disposed within the aperture (<NUM>) of the cam (<NUM>) and connected to the drive system; and
a biasing member (<NUM>) disposed within the aperture (<NUM>) and preloaded between an interior surface of the aperture (<NUM>) of the cam and the hub housing (<NUM>);
characterized in that the cam (<NUM>) moves relative to the hub housing (<NUM>) with the biasing member (<NUM>) compressing between the hub housing (<NUM>) and interior surface of the cam (<NUM>) when the cam assembly is rotated through the plurality of intermediate positions and the shift fork (<NUM>) remains in the disengaged position due to an interference; and
in that the cam (<NUM>) moves relative to the hub housing (<NUM>) with the biasing member (<NUM>) expanding to push the cam (<NUM>) against the shift fork (<NUM>) such the shift fork (<NUM>) moves through the stroke length from the disengaged position to the engaged position upon clearance of the interference.