Patent Description:
Vehicles include a driveline, which is used to transmit rotational drive from the vehicle's power plant to the wheels. Typical driveline components include, for example, transmissions, transfer cases, front and rear axles, and drive shafts. Many driveline components have a rotatable and/or slidable member that is movable between multiple positions using an actuator during vehicle operation. Examples include transmission and transfer case shift collars and park locks. A common challenge in designing driveline components is providing an actuator system that is compact, durable, efficient and cost-effective.

<CIT> discloses linear actuator mechanisms for vehicle disconnect/connect systems having a shift fork and a stationary guide rod extending though the shift fork. The mechanism includes a drive nut, a drive screw extending through the drive nut, a first spring plate, a second spring plate, and a compression spring positioned between a radially extending portion of the first spring plate and a radially extending portion of the second spring plate. A second radially extending portion of the first spring plate and a second radially extending portion of the second spring plate are in contact with the drive nut on axially opposite sides of the drive nut. The first and second spring plates, and the spring, are moveable axially along the stationary guide rod by the drive nut to compress the compression spring.

An aspect of the present invention relates to an actuator module set out in claim <NUM>.

An actuator module for a driveline assembly includes, among other things, a cover housing and a fork driving unit supported by the cover housing. The fork driving unit includes a fork driver for moving a shift fork and a pusher assembly coupled to the fork driver by spaced apart pusher ends. The fork driving unit also includes a drive assembly carried by the pusher assembly to translate the fork driver relative to the cover housing. The fork driving unit further includes a spring that biases the pusher assembly and fork driver to a neutral position relative to one another.

The actuator module includes a fork shaft that is supported by the cover housing. The fork driver is slidably supported by the fork shaft between multiple shift positions. The drive assembly is arranged parallel to the fork shaft.

The fork driver includes first and second walls that extend from a central portion and are spaced apart from one another.

The first and second walls have shaped apertures. The pusher ends are received in the shaped apertures to permit the pusher assembly to axially slide relative to the fork driver between the neutral position and a transition position while preventing rotation of the pusher assembly relative to the fork driver.

In a further embodiment of the present invention, the cover housing assembly includes first and second cover portions that enclose the drive assembly.

In a further embodiment of the present invention, the actuator module includes a motor and a gearbox that is coupled to the motor and the drive assembly. The motor and the gearbox are arranged between the first and second cover portions.

According to the present invention, the pusher assembly includes first and second pushers that are joined by a drive nut with left-hand and right-hand threads. Each of the first and second pushers includes a flange seat that is received in a respective shape aperture of the first and second walls. Each of the opposing ends of the spring engages one of the first and second walls and the flange seats and one of the first and second pushers.

The drive nut has a threaded inner diameter that threadingly engages a threaded shaft of the drive assembly.

In a further embodiment of the present invention, the threaded shaft has first and second ends. The first end is coupled to a worm gear of a gearbox. The second end is supported by a bracket that is secured to the cover housing.

In an example out with the scope of the claims, the drive assembly has a drive axis and includes a rotary sensor assembly that has a rotary sensor with a sensor axis offset from the drive axis. The rotary sensor is operatively coupled to the drive assembly and configured to measure a position of the fork driver.

In a further embodiment of the present invention, the actuator module includes a linear sensor assembly that is mounted to the fork driver and is configured to measure a position of the fork driver.

In a further embodiment of the present invention, the actuator module includes a gearbox that is coupled to a motor and the drive assembly. The gearbox has a worm and a worm gear that is mounted to first and second gear housing brackets having an L-shape. Each of the first and second gear housing brackets include a mounting flange that is secured to the cover housing.

In a further embodiment of the present invention, the motor is connected to the worm. The drive assembly is connected to the worm gear.

In an example out with the scope of the claims, an actuator module for a driveline assembly includes a cover housing, a motor that is supported relative to the cover housing and a fork driving unit that is supported by the cover housing. The fork driving unit includes a fork driver and a drive assembly that is configured to translate the fork driver relative to the cover housing. A gearbox is coupled to the motor and the drive assembly. The gearbox is supported relative to the cover housing.

In a further example out with the scope of the claims, the gearbox has a worm and a worm gear that is mounted to first and second gear housing brackets having an L-shape. Each of the first and second gear housing brackets include a mounting flange that is secured to the cover housing.

In a further example out with the scope of the claims, the first and second gear housing brackets include holes that are configured to receive bushings that support cylindrical ends of the worm and the worm gear.

In a further example out with the scope of the claims, the drive assembly includes a threaded shaft with first and second ends. The first end is coupled to the worm gear. The second end is supported by a bracket that is secured to the cover assembly. A bracket supports a worm and a bearing that receives the first end.

In another example out with the scope of the claims, an actuator module for a driveline assembly includes a cover housing, a printed circuit board, a motor that is supported relative to the cover housing and a fork driving unit that is supported by the cover housing. The fork driving unit includes a fork driver. A sensor is in communication with the printed circuit board and is arranged in relation to the fork driving unit to measure a position of the fork driver.

In a further example out with the scope of the claims, the actuator module includes a gearbox that is coupled to the motor and a drive assembly that is configured to translate the fork driver relative to the cover housing. A gearbox is supported relative to the cover housing. The drive assembly has a drive axis. The sensor includes a rotary sensor assembly that has a rotary sensor with a sensor axis offset from the drive axis. The rotary sensor is operatively coupled to the drive assembly and is configured to measure the position of the fork driver.

In a further example out with the scope of the claims, the drive assembly includes a threaded shaft. The rotary sensor assembly includes a drive pulley that is attached to threaded shaft. An anchor pin is mounted to the cover housing to support a follow pulley to which the rotary sensor is mounted. A belt interconnects the drive and follow pulleys.

In a further example out with the scope of the claims, the sensor includes a linear sensor assembly that is mounted to the fork driver and is configured to measure the position of the fork driver.

The invention can be further understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:.

A driveline assembly <NUM>, shown in <FIG>, includes an actuator module <NUM> that is used to shift a component within the driveline assembly between multiple positions. In one example, the driveline assembly <NUM> is a gearbox, but other driveline components are contemplated, such as a transfer box, or a park lock. A shifting member <NUM>, such as a shifting sleeve, is arranged within a housing <NUM> of the driveline assembly <NUM>. The shifting sleeve includes a collar having an annular groove (not shown), as is known. The actuator module <NUM> includes a shift fork <NUM> that cooperates with the shifting member <NUM> and is received in the collar. Sliding the shift fork <NUM> axially moves the shifting sleeve between multiple positions corresponding to different transmission gears positions.

The actuator module <NUM> is housed with respect to a cover housing <NUM> having first and second cover portions <NUM>, <NUM> that are secured to one another about a gasket <NUM>. The first cover portion <NUM> includes a "wet" first side <NUM> facing a cavity <NUM> of the housing <NUM> that is exposed to lubricant and a "dry" second side <NUM> facing the second cover portion <NUM> that is sealed from the lubricant. The actuator module <NUM> contains all the components that are needed to provide shifting to driveline component and can be secured to the housing <NUM> as a single unit.

The second side <NUM> of the first cover portion <NUM> includes a pocket <NUM> that receives an electric motor <NUM> supported by a mounting bracket <NUM>. The mounting bracket <NUM> is secured by fasteners <NUM> to holes <NUM> in the first cover portion <NUM>. The motor <NUM> may be a brushed or brushless DC motor.

Bosses <NUM> are provided on the second side <NUM> and include holes <NUM>. A printed circuit board (PCB) <NUM> is secured to the bosses <NUM> by fasteners <NUM>. Terminals <NUM> from the PCB <NUM> extend to a connector <NUM> that is carried by the second cover portion <NUM> when the actuator module <NUM> is fully assembled. The connector <NUM> receives command signals from the vehicle that control the shifting of the driveline assembly.

A gearbox <NUM> couples the motor <NUM> to a drive assembly <NUM>, which translates the shift fork <NUM>. The motor <NUM> is arranged between the first and second cover portions <NUM>, <NUM> in the dry side, and the gearbox <NUM> and drive assembly <NUM> are mounted to the first cover portion <NUM>. In one example, the gearbox <NUM> includes first and second gear housing brackets <NUM> that have an L-shape. The brackets <NUM> each include mounting flanges <NUM> that are secured by fasteners <NUM> to holes <NUM> in the first cover portion <NUM>. In this manner, a customized gearbox <NUM> may be easily swapped in and out of the actuator module <NUM> for a given driveline assembly application, enabling customized gear ratios for the specific application.

A fork driving unit <NUM> cooperates with the drive assembly <NUM>. Referring to <FIG>, the fork driving unit <NUM> includes a fork driver <NUM> that is mounted to a fork shaft <NUM>, which has its opposing ends supported in bosses provided by the first side <NUM> of the first cover portion <NUM>. The fork shaft <NUM> may be fixed against rotation as it need not rotate during operation. In the example shown, the fork driver <NUM> includes a central portion <NUM> that supports first and second walls <NUM>, <NUM> that are spaced apart from one another to form a C-shaped configuration. The fork <NUM> is disposed within the central portion <NUM>. Bores <NUM> are provided in the central portion <NUM> and in the fork <NUM> to slidably support the fork driving unit <NUM> on the fork shaft <NUM>, which is parallel to the drive assembly <NUM>.

Referring to <FIG>, the gearbox <NUM> uses interchangeable brackets <NUM> for simplicity. The brackets <NUM> can be located with respect to one another by complementary dimples and depressions or secured using fasteners. The brackets <NUM> support a worm <NUM> coupled to a worm gear <NUM>. Worm gear <NUM> includes an opening <NUM> having a complementary shape to the second end <NUM> for mating with threaded shaft <NUM>. If desired, holes in the brackets <NUM> may receive pressed-in bushings to support cylindrical ends of the worm <NUM> and the worm gear <NUM>. Washers may be used to reduce friction. Different sets of worm/worm gears can be used in the gearbox <NUM>. In one example, the gearbox <NUM> can be configured to provide a gear reduction ratio of up to <NUM>.

Referring to <FIG>, shaped apertures <NUM>, for example, a quadrangular shape, are provided in each of the first and second walls <NUM>, <NUM>. A pusher assembly includes first and second pushers <NUM>, <NUM> respectively having first and second pusher ends <NUM>, <NUM> received within respective apertures <NUM> of the first and second walls <NUM>, <NUM>. The first and second walls <NUM>, <NUM> each include inner surfaces disposed about the aperture <NUM> to provide a seat <NUM>. A spring <NUM> is arranged between the first and second walls <NUM>, <NUM> and engage the seats <NUM> and flange seats of the pusher ends <NUM>, <NUM>. The spring <NUM> is configured to bias the pusher assembly and the fork driver <NUM> to a neutral position relative to one another. The pusher ends <NUM>, <NUM> are received within the aperture <NUM> in a slip fit relationship to permit the pusher assembly to actually slide relative to the fork driver <NUM> between the neutral position and a transition position while preventing rotation of the pusher assembly relative to the fork driver <NUM>. This configuration enables the smooth operation of the actuator module for example during a shifting sequence of the shifting member <NUM>, avoiding jarring engagement of the shifting member <NUM> with its mating component.

The drive assembly <NUM> includes a driving nut <NUM> having a flange <NUM>. A threaded outer diameter <NUM> of the driving nut <NUM> secures to complementarily-shaped threaded inner diameter <NUM> of the spring pusher <NUM>. This enables the pusher assembly to be installed onto the driving nut <NUM> and about the spring <NUM> during assembly.

The driving nut <NUM> includes a threaded inner diameter <NUM> that cooperates with a leadscrew or threaded shaft <NUM> of the drive assembly <NUM>. The threaded shaft <NUM> includes a first end <NUM> having a feature, such as a square end, that connects to the gearbox <NUM>. A bearing <NUM> supports the first end <NUM> for rotation with respect to the first cover portion <NUM>. The threaded shaft <NUM> includes a second end <NUM> supported by a bracket <NUM> using a lock nut <NUM> secured to the second end <NUM>. The bracket <NUM> is mounted to the first cover portion <NUM> along with a reinforcing plate <NUM> that is secured to the first cover portion <NUM> by fasteners <NUM> extending through holes <NUM> (<FIG>).

The PCB <NUM> communicates with a rotary sensor assembly <NUM> and a linear sensor assembly <NUM> that monitor the movement of various elements within the actuator module <NUM> to ensure that the driveline assembly <NUM> is shifted into its desired gear in response to a shifting command from the vehicle. In the example, rotor sensor assembly <NUM> is used to monitor the position and speed input to the fork driving unit <NUM>, and the linear sensor assembly <NUM> is used to monitor the position and speed output from the fork driving unit <NUM>.

Referring to <FIG>, the rotary sensor assembly <NUM> measures the rotational position of the drive assembly <NUM> to determine the position of the shift fork <NUM>. The rotary sensor assembly <NUM> includes a drive pulley <NUM> mounted to the lock nut <NUM> at a keyed interface. A follow pulley <NUM> is driven by the drive pulley <NUM> via a belt <NUM> providing a <NUM>:<NUM> ratio. The follow pulley <NUM> is supported by the first side <NUM> of the first cover portion <NUM> with a pin <NUM> mounted to a boss. A rotary sensor <NUM> is mounted to the drive pulley <NUM>, and a connector <NUM> is secured to the pin <NUM> to capture the drive pulley <NUM> and rotary sensor <NUM>. In this manner, the drive assembly <NUM> has a drive axis, and the rotary sensor <NUM> has a sensor axis offset from the drive axis. This configuration enables the rotary sensor <NUM> to be located in position remote from the threaded shaft <NUM> for improved packaging.

Referring to <FIG>, the linear sensor assembly <NUM> is supported by the fork driving unit <NUM> to measure the axial position of the shift fork <NUM>. The linear sensor assembly <NUM> includes a sensor holder <NUM> that is mounted to the central portion <NUM> of the fork driver <NUM>. The sensor holder <NUM> includes a channel <NUM> received in a lip <NUM> of the central portion <NUM>, which takes advantage of the stamped sheet metal features of the fork drive <NUM>. Snaps <NUM> provided by the sensor holder <NUM> cooperate with notches <NUM> in the central portion <NUM>. A linear sensor <NUM> is mounted within the sensor holder <NUM>.

Referring to <FIG> and <FIG>, a separate bracket <NUM> may be used to house a bearing <NUM> supporting one end of the threaded shaft <NUM>. The bracket <NUM> includes a first bracket portion <NUM>, which may be cast, secured to the cover housing <NUM>' using a plate <NUM> and fasteners <NUM>. The second bracket portion <NUM>, which may be stamped sheet metal, includes locating pins <NUM> received in corresponding recesses in the first bracket portion <NUM> to capture the bearing <NUM> within a pocket in the first bracket portion <NUM> using fasteners <NUM>. The bearing <NUM> abuts a shoulder <NUM> on the threaded shaft <NUM> and is clamped thereto by a nut <NUM> freely disposed within an opening <NUM> in the second bracket portion <NUM>.

It is desirable for the lateral outer faces of the first and second spring pushers <NUM>, <NUM> to be flush with the outer lateral faces of the fork support <NUM> (<FIG>). To this end, the driving nut <NUM> includes opposing right-hand and left-hand threads that are threadingly secured to the first and second spring pushers <NUM>, <NUM>, so as to provide a turnbuckle. The annular flange <NUM> includes notches <NUM> about its periphery so that a tool can be used to adjust the distance between the spring pushers during assembly to ensure flange seats are flush with those of the fork support, which ensures there is no undesired clearances or take-up in the drive assembly. Any motion in the system without movement in the fork <NUM> may lead to poor performance.

Rather than using a separate gearbox (e.g., <FIG>), the bracket <NUM> is also used to support the gears. The worm gear <NUM>' is keyed to the end of the threaded rod <NUM> as previously described. The second bracket portion <NUM> has a flange <NUM> with a hole <NUM> that supports an end of the worm <NUM>' by a first bushing <NUM>, as shown in <FIG>. The opposite end of the worm <NUM>' is supported by a second bushing <NUM> that is mounted to the cover housing <NUM>'. Seals <NUM> in the second bushing <NUM> isolate the motor from the lubricant in the cavity <NUM>.

Referring to <FIG> and <FIG>, a bracket <NUM> has a hole <NUM> that supports an end of the fork shaft <NUM> (<FIG>). This same bracket <NUM>, mounted to the cover housing <NUM>' (e.g., first cover portion <NUM>) also supports the rotary sensor assembly <NUM>, which may be a belt drive (<FIG>) or a gear train. The driven gear <NUM> receives an end <NUM> of the threaded rod <NUM> (<FIG>) to provide rotational input to the rotary sensor assembly <NUM>. The rotation of the threaded rod <NUM> is communicated to the driven gear <NUM> via intermediate gears <NUM>. The rotary sensor <NUM> rotates in unison with the driven gear <NUM> via connector <NUM>. One or more of the gears <NUM>, <NUM> are supported for rotation relative to the bracket <NUM> by pins <NUM> and circlips <NUM>. Having the threaded rod <NUM> and the rotary sensor assembly <NUM> supported by a common bracket reduces tolerances in the system.

Turning to <FIG> and <FIG>, another example fork driver <NUM> provides increased versatility. A reinforcement plate <NUM> is secured to end faces of the first and second walls <NUM>, <NUM> using fasteners <NUM>. The reinforcement plate <NUM> captures the spring pushers and prevents racking of the assembly. A fork support <NUM> is secured to the central portion <NUM> connecting the first and second walls <NUM>, <NUM> with fasteners <NUM>, such as rivets or welds, for example. In this way, different fork supports may be selected and secured to a common spring pusher support depending upon the application.

A bearing assembly <NUM> supports the fork driver <NUM> for sliding motion along the fork shaft <NUM> in applications having increased loads. A spacer <NUM> extends through the fork (<NUM> in the figures). Bearing end caps <NUM> are threaded onto the spacer <NUM> and clamp about lateral walls <NUM> of the fork support <NUM>. In the example, shown in <FIG>, the bearing end caps <NUM>' are bushings, whereas the example bearing end caps <NUM> illustrated in <FIG> include rolling elements <NUM> for increased load capability. The example bearing assembly <NUM> spreads the fork load over a relatively large distance on the fork shaft <NUM>, which provides increased stability under high loads.

It should also be understood that although a particular component arrangement is disclosed in the illustrated embodiment of the present invention, other arrangements are possible within the scope of the claims. Although particular step sequences are shown and described, it should be understood that steps may be performed in any order, separated or combined unless otherwise indicated.

Claim 1:
An actuator module (<NUM>) for a driveline assembly comprising:
a cover housing (<NUM>);
a fork driving unit (<NUM>) supported by the cover housing (<NUM>), the fork driving unit (<NUM>) including:
a fork driver (<NUM>) for moving a shift fork;
a pusher assembly coupled to the fork driver (<NUM>) by spaced apart pusher ends (<NUM>, <NUM>);
a drive assembly (<NUM>) carried by the pusher assembly to translate the fork driver (<NUM>) relative to the cover housing (<NUM>); and
a spring configured to bias the pusher assembly and fork driver (<NUM>) to a neutral position relative to one another,
the actuator module (<NUM>) further comprising a fork shaft (<NUM>) supported by the cover housing (<NUM>), and the fork driver (<NUM>) slidably supported by the fork shaft (<NUM>) between multiple shift positions, wherein a threaded shaft (<NUM>) of the drive assembly (<NUM>) is arranged parallel to the fork shaft (<NUM>),
wherein the fork driver (<NUM>) includes first and second walls (<NUM>, <NUM>) extending from a central portion (<NUM>) and spaced apart from one another, the first and second walls (<NUM>, <NUM>) have shaped apertures, and the pusher ends (<NUM>, <NUM>) are received in the shaped apertures (<NUM>) to permit the pusher assembly to axially slide relative to the fork driver (<NUM>) between the neutral position and a transition position while preventing rotation of the pusher assembly relative to the fork driver (<NUM>);
wherein the pusher assembly further includes first and second pushers (<NUM>, <NUM>) joined by a drive nut (<NUM>) with left-hand and right-hand threads on its outer diameter, each of the first and second pushers (<NUM>, <NUM>) includes a flange seat received in the respective shape aperture (<NUM>) to permit the pusher assembly to axially slide relate to the fork driver (<NUM>), and each of opposing ends of the spring (<NUM>) engages one of the first and second walls and the respective flange seat of the first and second pushers, wherein the drive nut (<NUM>) has a threaded inner diameter (<NUM>) that threadingly engages a threaded shaft (<NUM>) of the drive assembly (<NUM>).