Position-based lubrication control strategy for open differentials

Abstract

The exemplary illustrations relate to a differential, such as a disconnectable differential, and related methods. A disconnectable differential may include two side gears configured to deliver torque from an output gear or differential housing to a corresponding wheel when the differential is engaged. Each side gear may be configured to receive torque from the output gear while allowing differential speed between the side gears. The disconnectable differential may also include a disconnecting device configured to disconnect the output gear from the two side gears, thus disengaging the differential. The disconnectable differential may further include a position sensor configured to determine the rotational position of the output gear.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 220,417, filed July 9, 2021, the contents of which are hereby expressly incorporated by reference in their entirety. TECHNICAL FIELD

[0003] The present disclosure relates to a differential, and more particularly to a drop-off differential. BACKGROUND

[0004] In all-wheel drive vehicles, it is possible to disconnect the power of one of the axles to improve the propulsion system efficiency under constant vehicle speed conditions. While this can be applicable to all types of vehicles, in the case of electric vehicles, disconnecting the axle can be particularly useful because in electric vehicles, the range of the vehicle can be relatively more important. In the case of a vehicle propulsion system with a single motor e-axle, i.e., where an electric motor drives a pair of wheels on a single axle, when it is desired to disconnect the axle, the motor can be disconnected by using a differential with a disconnect mechanism. In some examples, the output gear can be disengaged from the internal components of the differential. Thus, the motor and the output gear of the axle can be slowed down or stopped, while the internal components of the differential are rotated by the wheels of the axle. The moving internal components of the differential typically need to be lubricated in the disconnected state, while the output gear / housing remains stationary. Typically, a lubrication level is maintained inside the differential to ensure adequate lubrication. There is typically a trade-off between lubrication and propulsion system efficiency. More specifically, the moving internal components of the differential are relatively more lubricated to the extent that a higher lubrication level is maintained inside the differential, but the propulsion system efficiency is reduced. That is, a greater level of lubrication inside the differential necessarily requires a higher resistance on the moving internal components of the differential, which is applied to the wheels of the axle. SUMMARY

[0005] The solution described in detail herein generally increases the degree of lubrication of the moving internal components of the differential with a given amount of lubrication. Thus, the lubrication level can generally be reduced with respect to previous approaches, increasing the propulsion system efficiency of the axle while ensuring that the moving components of the differential have adequate lubrication when in the disconnected state. With respect to previous approaches, the power loss associated with the axle can be correspondingly reduced.

[0006] In at least some of the exemplary illustrations, the disconnectable differential includes two side gears configured to deliver torque from the output gear to the respective wheels when the differential is engaged. Each side gear is configured to receive torque from the output gear while allowing differential speed between the side gears. The disconnectable differential also includes a disconnecting device configured to disconnect the output gear from the two side gears, thus disengaging the differential. The disconnectable differential also includes a position sensor configured to determine the rotational position of the output gear.

[0007] In at least some exemplary methods, the output gear is configured to rotate when the differential is in the disengaged state.

[0008] In at least some examples, the output gear can be configured to rotate when the differential is in the disengaged state in response to a determined rotational position of the output gear differential housing.

[0009] In at least some examples, the differential housing that rotates with the output gear includes a housing bore configured to align with a fuel injector configured to provide lubrication to the moving internal components of the differential via the housing bore, wherein the fuel injector is not obstructed by the housing when the housing bore is aligned with the fuel injector.

[0010] In at least some examples, the differential housing that rotates with the output gear includes a housing bore configured to allow lubrication of the differential's moving internal components via an injector, wherein the output gear is configured to rotate in response to determining that the housing bore is misaligned with the injector.

[0011] In at least some examples, the disconnect differential includes a mark fixed to the output gear, wherein a position sensor is configured to determine the rotational position of the output gear based on the proximity of the mark to the position sensor.

[0012] In at least some exemplary methods, the differential housing, which rotates with the output gear, includes a lubrication hole configured to allow an injector to deliver lubricant to the internal region of the disconnect differential.

[0013] In at least some examples, the disconnecting device includes a moving collar configured to engage the external splines with the internal splines when the disconnectable differential is in the engaged state. In these methods, the differential may also include a spring that biases the moving collar toward an engaged position in which the disconnectable differential is engaged.

[0014] In at least some examples, the differential includes a controller that communicates with sensors.

[0015] In at least some exemplary methods, a vehicle is provided that includes a disconnectable differential with two side gears configured to deliver torque from a differential housing to a corresponding wheel when the differential is engaged. Each side gear may be configured to receive torque from the differential housing while allowing differential speed between the side gears. The vehicle may also include a disconnection device configured to disconnect an output gear from the two side gears, thereby disengaging the differential. The vehicle may further include a position sensor configured to determine the rotational position of the output gear.

[0016] In at least some examples, the vehicle also includes a controller that communicates with sensors. The controller is configured to rotate the differential housing when the differential is in the disengaged state, in response to a determined rotational position of the output gear.

[0017] In another exemplary illustration, the method includes operating a differential in a engaged state, wherein torque received from a motor is transmitted via a differential housing to a pair of half-shafts. The differential housing at least partially defines a lubrication housing, wherein torque is transmitted from the differential housing to the half-shafts via two side gears configured to receive torque from the differential housing while allowing differential speed between the side gears. The method further includes disconnecting the side gears from the housing via a disconnecting device, thereby placing the differential in an disengaged state. In the disengaged state, the housing is not driven by the two side gears when the side gears are rotated by their respective wheels. The method also includes sensing the rotational position of the housing.

[0018] In at least some exemplary methods, the method also includes rotating the housing when the differential is in the disengaged state.

[0019] In some examples, the method also includes rotating the housing in response to the sensed rotational position of the housing while the differential is disengaged.

[0020] In some examples, the method also includes aligning a housing bore with a fuel injector configured to provide lubrication to moving internal components via the housing bore. In some of these examples, the fuel injector is not obstructed by the housing when the housing bore is aligned with the fuel injector.

[0021] Some examples may also include determining that a housing bore defined by the housing is misaligned with an injector configured to provide lubrication to moving internal components through the housing bore. In these examples, the housing is rotated in response to determining that the housing bore and injector are misaligned.

[0022] In some exemplary methods, the rotational position of the differential housing is determined via a mark fixed to the housing. In some of these examples, the rotational position of the differential housing is determined based on the proximity of the mark to a position sensor.

[0023] In some exemplary methods, the differential housing at least partially encloses the two side gears. Attached Figure Description

[0024] The above and other features, properties, and various advantages of this disclosure will become more apparent when considering the following specific embodiments in conjunction with the accompanying drawings, wherein:

[0025] Figure 1 A cross-sectional view of an exemplary disconnect differential according to some embodiments of the present disclosure is shown;

[0026] Figure 2A The disconnected state is shown in some embodiments according to this disclosure. Figure 1 A cross-sectional view of a disconnectable differential, in which the holes in the differential housing are aligned with the fuel injectors;

[0027] Figure 2B The disconnected state is shown in some embodiments according to this disclosure. Figure 1 and 2A A cross-sectional view of a disconnected differential, in which the housing is rotated such that the holes in the housing are misaligned with the fuel injectors;

[0028] Figure 3 A cross-sectional view of an exemplary disconnectable differential according to some embodiments of the present disclosure is shown;

[0029] Figure 4 A schematic diagram of an exemplary vehicle with a disconnectable differential according to some embodiments of the present disclosure is shown; and

[0030] Figure 5 A flowchart illustrating an exemplary process for lubricating a differential according to some embodiments of the present disclosure is shown. Detailed Implementation

[0031] Typically, the exemplary method described herein may employ a position sensor capable of determining the tangential or rotational position of the differential housing. The housing may be provided with a housing aperture that allows a fuel injector to supply lubricant from outside the housing to the moving parts of the differential within the housing. The position sensor may allow the housing aperture to be aligned with the fuel injector, which has a stationary rotational position relative to the differential. For example, a motor may be used to rotate the housing to align the housing aperture with the fuel injector, thereby allowing the fuel injector to reach the moving internal parts of the differential when the drivetrain is disengaged.

[0032] An exemplary position sensor can be any position sensor capable of monitoring the tangential position of the differential housing or output gear (to the extent that the output gear is fixed to the differential housing). Incremental encoders, Hall effect sensors, resolvers, etc., can be employed, by way of example only. In some examples, the position of the differential housing can be monitored or sensed via a rotating component connected to it with a rotational position, which can be expressed as a function of the position of the output gear. By way of example only, a resolver for a motor connected to the housing can measure the angular position of the motor rotor and thereby determine the angular position of the differential housing. The position sensor can continuously monitor the position of the housing bore, at least relative to the fuel injector. Once a disengagement signal is received, the control logic can use the position sensor or encoder to ensure that the housing bore is aligned with the fuel injector, where the speed of the output gear is zero. To the extent that the housing bore is misaligned with the fuel injector, a motor associated with the axle can be used to rotate the housing to the extent necessary to align the housing bore with the fuel injector.

[0033] Turn now Figure 1 , Figure 2A , Figure 2B and Figure 3 An exemplary differential assembly 100 is shown. First, refer to... Figure 1 The differential assembly 100 typically includes a differential housing 101, which includes an output gear 101' or ring gear structure fixed for rotation with the housing 101. By way of example only, the output gear 101' may be fixed to or formed in the outer surface of the housing 101. The output / ring gear 101' may consist of a pinion (… Figure 1 (Not shown in the image) Driven by a vehicle powertrain such as an electric motor, the pinion gear 101' is driven by the vehicle's powertrain system. The output gear 101' and housing 101 can be enclosed within an outer housing. Figure 1 (Not shown in the diagram). Housing 101 typically provides a housing 130 for a plurality of interlocking components that are part of differential assembly 100. For example, the interlocking components may include at least a main shaft 104, which is rotatably supported in housing 101 at its opposite ends. As will be discussed further below, the main shaft 104 may be selectively disconnected from housing 101, allowing the main shaft 104 to rotate freely relative to housing 101. The main shaft 104 rotates a pair of side gears 106 via a differential gear 105 located at the end of the main shaft 104. Each side gear 106 drives a corresponding half-shaft or side shaft 107. The pinion may be positioned to translate rotational motion from a power system such as an electric motor, transmission, etc., to housing 101. The side gear 106 may ultimately drive the half-shaft 107 in response to the drive of the output gear 101' / housing 101, while allowing a relative speed difference between the two half-shafts 107, such as required for vehicle cornering, or when different speeds are required for the wheels 107 corresponding to the half-shafts 107 respectively.

[0034] existFigure 1 The differential 100 is shown in a connected state, where the output gear 101' / housing 101 transmits torque from the motor (not shown) to the half-shaft 107. In this connected state, torque flows from the housing 101 from the motor to the half-shaft 107, as shown in the diagram. Figure 1 As indicated by the arrows in the diagram, and now described in further detail, the differential 100 may have a disconnection device 135, which is typically configured to selectively engage and disengage torque transmission from the output gear 101' to the half-shaft 107. In the example shown, the disconnection device includes a lateral movement collar 102 that moves in a lateral direction relative to the output gear 101' and / or in a direction parallel to the axis of rotation of the output gear 101'. The output gear 101' may have an internal spline 113 that engages with an external spline 114 of the lateral movement collar 102. The movement collar 102 may define an internal spline 115 that engages with an external spline 116 of a gear nest 103. The gear nest 103 may include a bore surrounding a main shaft 104. The main shaft 104 can rotate a side gear 106 via a differential gear 105 disposed at either end of the main shaft 104. The side gear 106 may have an internal spline 117 that meshes with the external spline 118 of the half-shaft 107. Thus, torque can be transmitted from the housing 101 to the half-shaft 107, thereby allowing a motor (not shown) to power a wheel (not shown) associated with the half-shaft 107.

[0035] Differential 100 can be an open differential, i.e., allowing differential speed between side gears 106, resulting in rotation of differential gear 105. A wave spring 108 is shown that applies an axial force to the moving collar 102, thereby holding the collar 102 in an axial position such that the inner spline 115 of the moving collar 102 remains engaged with the outer spline 116 of the gear nest 103.

[0036] A housing bore 109 exists, defined by and therefore rotatable with the housing 101. The housing bore 109 can be a relatively small window, allowing the housing 101 to maintain a lubricant level within it. (Fuel injector) Figure 1 (Not shown) may point to housing 101 such that when housing 101 rotates, housing bore 109 passes through the injector, oil or lubricant is guided to internal components of differential 100, such as side gear 106, main shaft 104, differential gear 105, etc. Housing bore 109 may be of any convenient shape or configuration. By way of example only, bore 109 may form a generally cylindrical through-hole extending from the outside of housing 101 to an internal region of differential 100, which includes, for example, side gear 106, differential gear 105, main shaft 104, and gear nesting member 103.

[0037] Turn now Figure 2AThe differential 100 is shown in an open state, i.e., where the housing 101 and output gear 101' can decelerate or stop, while allowing the side gear 106 and half-shaft 107 to rotate, for example, due to the rotation of their associated wheels (not shown). In this state, the side gear 106 can be driven by the rotation of the half-shaft 107, but the housing 101 can remain stationary relative to the differential assembly 100. More specifically, the external spline 118 of the half-shaft 107 rotates the internal spline 117 of the side gear 106. The side gear 106 rotates the differential gear 105, thereby causing the main shaft 104 and gear nest 103 to rotate. However, the gear nest 103 disengages from the housing 101 because the disconnecting device 135 has been adjusted to disengage the differential 100. In the example shown, the moving collar 102 has been laterally displaced (against the force of the wave spring 108), such that the internal spline 115 of the moving collar 102 has disengaged from the external spline 116 of the gear nest 103. Therefore, the gear nest 103 rotates within the housing 101, and torque is not transmitted from the gear nest 103 to the collar 102 (or to the housing 101 or to the output gear 101'). Thus, the motor (not shown) associated with the differential 100 can be deactivated or stopped, for example, to reduce power consumption. In this disconnected state, the motor (not shown) can still rotate the housing 101 to align the housing bore 109 with the fuel injector 110. In one example, sensor 111 detects that the radial positioner 112 is positioned such that the housing bore 109 is aligned with the fuel injector 110. Sensor 111 can determine the rotational position of the housing 101 and / or the output gear 101' based on the proximity of the positioner 112 to sensor 111. For example, sensor 111 can be an incremental encoder configured to read the positioner 112 to determine the rotational position of the housing 101 and / or the bore 109. In another example, sensor 111 is a Hall effect sensor configured to determine the position of housing 101 and / or bore 109 based on the presence or absence of the magnetic field of positioner 112. In some examples, the position of housing 101 and / or bore 109 can be monitored or sensed via a rotating component connected with a rotational position, which can be expressed as a function of the position of housing 101 or output gear 101'. As an example only, an electric motor (not shown) supplying torque to output gear 101' / housing 101 can use a resolver to measure the angular position of the motor's output or rotor. When output gear 101' / housing 101 is driven by a gear driven by the motor, for example, in a rotational relationship with the motor, the angular position of housing 101 and / or bore 109 can be determined based on the known rotational position of the motor's rotor.Therefore, the housing 101 is rotatably positioned so that it does not obstruct the injector 110, which can freely guide lubricant to the moving parts of the differential 100, such as the end of the half-shaft 107, the side gear 106, the differential gear 105, the main shaft 104, and the gear nest 103.

[0038] Now for reference Figure 2B , such as in Figure 2A The differential 100 is shown in the disconnected state again, as in the example. However, in... Figure 2B In the middle, the housing 101 is rotated relative to each other, so that the housing hole 109 ( Figure 2B (Not shown) is not aligned with the injector 110. Therefore, the injector 110 is at least partially obstructed in directing lubrication to the internal components of the differential assembly 100 (e.g., the end of the half-shaft 107, side gear 106, differential gear 105, main shaft 104, and gear nest 103). As will be further discussed below, in some exemplary methods, the misalignment of the housing bore 109 with the injector 110 may be detected, for example, based on the position sensor 111, and a motor may be used to drive the output gear 101' and / or the housing 101 to align the housing bore 109 with the injector 110 (e.g., as shown in the image). Figure 2A (As shown).

[0039] Turn now Figure 3 The diagram illustrates a differential 100, in which a main shaft 104, differential gear 105, and side gear 106 are each positioned within a housing 101. As shown, in some examples, the lower edge of each differential gear 105 is positioned such that it rotates through a volume of lubricant 119 having an upper surface 120, as illustrated herein. However, any other convenient level of lubrication may be used. Compared to previous methods, the amount of lubricant 119 required in the exemplary illustrations herein is relatively reduced, with the upper surface 120 located at a relatively lower position within the differential 100 compared to these previous methods, thereby reducing frictional losses in the differential 100 during the differential's disengaged state. Furthermore, the lubricant circulation is enhanced by the injector 110 through the housing bore 109 (see [reference]). Figure 2A Therefore, the moving internal components of the differential 100 can still be adequately lubricated.

[0040] As stated above regarding each of the exemplary methods described herein, a lower level / amount of lubrication can be used in the differential due to the enhanced lubrication circulation to the moving differential components. Therefore, the exemplary differential assembly achieves a reduction in frictional losses compared to previous methods. While the reduction in frictional losses will vary based on operating factors and conditions such as oil type, viscosity, operating temperature, gear size, and / or operating speed, the exemplary methods are estimated to achieve a three percent (3%) reduction in power loss.

[0041] Figure 4 A block diagram of an exemplary electric vehicle 400 having a control system for controlling one or more drive units and a differential assembly 100, according to some embodiments of the present disclosure, is shown. While the examples herein are described in the case of electric vehicle 400, it should be understood that the various exemplary illustrations herein are not limited to any other type of vehicle. By way of example only, in other examples, vehicle 400 may be powered entirely by an internal combustion engine vehicle, or may have a hybrid power system including one or more electric motors in addition to an internal combustion engine. Electric vehicle 400 includes a battery pack 430, an electric vehicle subsystem 410, suspension, and wheels. Electric vehicle subsystem 410 includes, for example, a rear drive unit 412, a front drive unit 414, control circuitry 416, an auxiliary system 418, an input interface 420, and any other suitable corresponding devices. The electric vehicle 400 includes a power transmission mechanism 450 (e.g., a gearbox, pulley system, or other mechanism including a differential assembly 100 for transmitting axle power) corresponding to one drive axle (e.g., a rear drive axle) and a power transmission mechanism 460 corresponding to another drive axle (e.g., a front drive axle). The vehicle 400 may include... Figure 1 , Figure 2A , Figure 2B and Figure 3 The differential assembly 100 is part of either or both of the power transmission mechanisms 450 and 460. The vehicle subsystem 410 can be used, for example, to monitor the operation of the vehicle 400 (e.g., sensor signals) and control... Figures 1 to 3 The exemplary arrangement and actuators of any of the drive systems (e.g., differential actuators or fuel injector actuators) or otherwise manage the operation of vehicle 400. For illustration, each of power transmission mechanisms 450 and 460 may include a differential 100, and vehicle subsystem 410 may be used to control the engagement / disengagement state of each differential 100, control the rotational position of each housing 101 to align the corresponding fuel injector 110 with the corresponding housing bore 109 in the disengaged state, and control each fuel injector 110 to provide lubrication to the corresponding internal region 130 of the differential assembly 100 through the corresponding bore 109.

[0042] In some embodiments, control circuitry 416 may include processing devices, memory, power management components, any other suitable components for controlling one or more drive units (e.g., front drive unit 414 and rear drive unit 412), or any combination thereof. For example, control circuitry 416 may (e.g., using power stored in battery pack 430) control the phase of current flowing to the electric motors of one or more drive units (e.g., the amount and direction of current). In another example, control circuitry 416 may control differential operation in a single drive unit or in a dual drive unit (e.g., using an electromagnetically actuated differential). In some embodiments, control circuitry 416 is configured to actuate and de-actuate differential actuators. For example, control circuitry may provide control signals (e.g., communication, power, or both) to (i) one or more differential actuators of power transmission mechanisms 450, 460, or both, (ii) one or more fuel injector actuators of power transmission mechanisms 450, 460, or both, or (iii) combinations thereof. In another example, the control signal can be binary (e.g., an on / off application of DC voltage), analog (e.g., the control signal can be proportional to a voltage range, pulse width modulation, or pulse density modulation), oscillatory (e.g., and AC signals or other oscillating signals), any other suitable waveform or shape (e.g., square wave, sawtooth wave, triangular wave, rectified sine wave), or any combination thereof. In some embodiments, the actuator is spring-loaded or otherwise biased into an engaged or disengaged state, and the application of electrical, hydraulic, or pneumatic power from vehicle subsystem 410 causes a change in state (e.g., from engaged to disengaged, or from disengaged to engaged).

[0043] In some implementations, the control circuit 416 may include one or more sensors, one or more sensor interfaces (e.g., for sensors included as part of the drive unit), corresponding wiring, corresponding signal conditioning components, any other suitable components for sensing the state of the drive unit, or any combination thereof. For example, such as Figure 4As illustrated in the example, control circuitry 416 may include a sensor interface for communicating with position sensors included in power transmission mechanisms 450 and / or 460 (e.g., for each differential housing). The sensors in power transmission mechanisms 450, 460 may be position sensors, but in some examples, speed sensors (e.g., rotary encoders), current sensors, voltage sensors, temperature sensors, any other suitable sensors, or any combination thereof may be provided. In some embodiments, control circuitry 416 may be implemented by a central controller, multiple distributed control systems, embedded systems, or any combination thereof. For example, control circuitry 416 may be implemented at least in part by an electronic control unit (ECU). In another example, the electric vehicle may include a power electronics system controlled by the ECU and configured to manage current flowing to one or more electric motors of one or more drive units. Rear drive unit 412 may be coupled to the wheels of the electric vehicle via half-shafts, constant speed engagements, one or more suspension / steering components, any other suitable couplings, or any suitable combination thereof. The front drive unit 414 can be coupled to the wheels of the electric vehicle via a half-shaft, a constant speed engagement, one or more suspension / steering components, any other suitable coupling, or any suitable combination thereof. For example, the wheels can be mounted to a hub including a half-shaft bearing, wherein the hub is coupled to a suspension / steering component mounted to the frame (e.g., where the drive unit is also mounted to the frame).

[0044] In some embodiments, the drive system may include a first drive unit and optionally a second drive unit, each including a differential assembly. In some embodiments, in addition to including drive units (e.g., a single drive unit or dual drive units), the drive system may also include processing equipment configured to manage motor operation, manage regeneration (e.g., using the motor as a generator), perform any other control functions, or any combination thereof. In some embodiments, the drive unit may include at least one sensor configured to sense wheel slip (e.g., a sensor interface coupled to control circuitry), and the control circuitry may be further configured to receive signals from at least one sensor, detect wheel slip, and activate the differential assembly in response to the detection of wheel slip. For example, the sensor may detect shaft speed (e.g., output shaft speed measured by an encoder) or output torque (e.g., output shaft torque or motor torque). In some embodiments, the drive system may include an accelerator pedal configured to indicate a desired speed (e.g., by being pressed by a user), and the processing equipment may receive signals from the accelerator pedal, determine speed parameters based on the signals, and activate one or more differential assemblies, one or more motors, or combinations thereof if the speed parameters are above a threshold. For example, if a user depresses the accelerator pedal "all the way down" (e.g., more than 50% of the required speed), the control circuitry can activate one or more differential components to deliver torque from one or more motors to the wheels. In some implementations, the control circuitry can activate and deactivate the differential components based on road conditions (e.g., icy roads, puddles, strong winds), drive mode (e.g., off-road mode, sport mode, or traction mode), any other suitable criteria, or any combination thereof.

[0045] Turn now Figure 5 An exemplary process 500 for operating a differential, such as that found in a motor vehicle like an electric vehicle, is illustrated. At block 505, process 500 operates the differential in a engaged state. For example, as described above, torque received from the motor can be transmitted via differential housing 101 to a pair of half-shafts 107, each having an associated wheel. Additionally, the differential housing may at least partially define a lubrication housing, such as housing 130, which is configured to generally contain a certain amount of lubrication. Furthermore, torque can be transmitted from the differential housing to the half-shafts 107 via one or more moving internal components disposed within the lubrication housing, wherein each of the side gears is configured to receive torque from the housing while allowing differential speed between the side gears. Process 500 can then proceed to block 510.

[0046] At frame 510, process 500 can disconnect the side gear from the housing via a disconnecting device, thereby disengaging the differential. For example, as described above, in Figure 2BIn this configuration, when the side gear 106 is rotated by its corresponding wheel, the movable collar 102 allows the housing 101 to be not rotated or driven by the two side gears 106.

[0047] Proceeding to frame 515, process 500 can sense the rotational position of the housing. For example, a position sensor 111 with a fixed position on housing 101 can be used to determine the radial position of a radial mark 112 located on housing 101. For example, the radial mark 112 can indicate the alignment of housing bore 109 with fuel injector 110. In another example, the position of the rotor of an electric motor driving housing 101 can be related to the rotational position of the housing, and therefore the position of housing bore 109 can be determined by a rotor / motor sensor.

[0048] Proceeding to frame 520, process 500 may, for example, query whether the housing and / or output gear are positioned such that housing bore 109 is aligned with injector 110 based on the position sensed at frame 515. If process 500 determines that housing bore 109 is not aligned with injector 110, process 500 may proceed to frame 525. At frame 525, when differential 100 is in the disengaged state, housing 101 may be rotated based on the position sensed at frame 515. For example, a controller or processor (e.g., Figure 4 The control circuitry 416 may be configured to determine, for example, whether the housing bore 109 is aligned with the injector 110 based on a position sensed at block 515. Alternatively or otherwise, the controller may determine the distance the housing / output gear should rotate to align the housing bore 109 with the injector 110. In this example, the controller may have a processor and memory in communication with the processor. The memory may include a computer-readable storage medium that tangibly embodies instructions that cause the controller to perform the various processes or steps thereof described herein.

[0049] Therefore, when process 500 determines that the housing 101 and / or output gear 101' needs to be rotated to improve differential lubrication, the housing 101 / output gear 101' can be rotated while the differential 100 is in the disengaged state. In one example, the controller / control circuit 416 is configured to rotate the housing 101 and / or output gear 101' in response to the determined rotational position of the housing 101 and / or output gear 101' while the differential is in the disengaged state. For example, the controller / control circuit 416 can drive a motor to rotate the housing 101 so that the housing bore 109 is aligned with the fuel injector 110, which is configured to provide lubrication to the moving internal components via the housing bore 109. Therefore, when the housing bore 109 is aligned with the fuel injector 110, the fuel injector 110 is generally not obstructed by the housing 101. Thus, lubrication can be effectively delivered to the moving internal components, thereby reducing the amount of lubrication required within the housing 101.

[0050] The foregoing description includes exemplary embodiments according to this disclosure. These examples are provided for illustrative purposes only and not for limiting purposes. It should be understood that this disclosure may be implemented in different forms than those expressly described and shown herein, and various modifications, optimizations, and variations accorded to the following claims can be implemented by those skilled in the art.

Claims

1. A disconnectable differential, the disconnectable differential comprising: Two side gears are configured to deliver torque from the output gear to the corresponding wheel when the disconnect differential is engaged, each of the side gears being configured to receive the torque from the output gear while allowing differential speed between the side gears; A disconnection device configured to disconnect the output gear from the two side gears, thereby placing the disconnectable differential in an open state. A position sensor configured to determine the rotational position of the output gear; as well as A differential housing that rotates with the output gear and includes a housing bore. When the disconnect differential is in the disconnected state, the position sensor allows the housing bore to align with a fuel injector configured to provide lubrication to the moving internal components of the disconnect differential via the housing bore.

2. The disconnectable differential of claim 1, wherein the output gear is configured to rotate when the disconnectable differential is in the disconnected state.

3. The disconnect differential according to claim 2, wherein the output gear is configured to rotate in response to a determined rotational position of the output gear when the disconnect differential is in the disconnected state.

4. The disconnectable differential according to claim 3, wherein when the housing bore is aligned with the fuel injector, the fuel injector is not blocked by the differential housing.

5. The disconnect differential of claim 3, wherein the output gear is configured to rotate in response to determining that the housing bore is misaligned with the fuel injector.

6. The disconnectable differential of claim 1, further comprising a mark fixed to the output gear, wherein the position sensor is configured to determine the rotational position of the output gear based on the proximity of the mark to the position sensor.

7. The disconnect differential of claim 1, wherein the disconnecting device includes a movable collar configured to engage an external spline with an internal spline when the disconnect differential is in the connected state, and wherein the disconnect differential further includes a spring biasing the movable collar toward the engaged position, wherein the disconnect differential is in the connected state.

8. The disconnectable differential of claim 1, wherein the disconnectable differential further comprises a controller communicating with the position sensor.

9. A vehicle, the vehicle comprising: A disconnectable differential having two side gears configured to deliver torque from an output gear to a corresponding wheel when the disconnectable differential is engaged, each of the side gears being configured to receive the torque from the output gear while allowing differential speed between the side gears; A disconnection device configured to disconnect the output gear from the two side gears, thereby placing the disconnectable differential in an open state. A position sensor configured to determine the rotational position of the output gear; as well as A differential housing that rotates with the output gear and includes a housing bore. When the disconnect differential is in the disconnected state, the position sensor allows the housing bore to align with a fuel injector configured to provide lubrication to the moving internal components of the disconnect differential via the housing bore.

10. The vehicle of claim 9, further comprising a controller in communication with the position sensor, wherein the controller is configured to rotate the differential housing in response to a determined rotational position of the output gear when the disconnect differential is in an open state.

11. A method of operating a differential, the method comprising: Operating a differential in a connected state, wherein torque received from a motor is transmitted via a differential housing to a pair of half-shafts, the differential housing at least partially defining a lubrication housing, wherein the torque is transmitted from the differential housing to the half-shafts via two side gears configured to receive the torque from the differential housing while allowing differential speed between the side gears; The side gear is disconnected from the differential housing via a disconnection device, so that the differential is in an open state, wherein the differential housing is not driven by the two side gears when the side gear is rotated by its corresponding wheel; as well as Sensing the rotational position of the differential housing, and The differential housing includes a housing bore. When the differential is in the open state, a position sensor configured to determine the rotational position of the output gear allows the housing bore to align with a fuel injector, which is configured to provide lubrication to the moving internal components of the differential via the housing bore.

12. The method of claim 11, further comprising rotating the differential housing while the differential is in the disengaged state.

13. The method of claim 12, wherein the differential housing is rotated in response to a sensed rotational position of the differential housing when the differential is in the disengaged state.

14. The method of claim 11, wherein when the housing bore is aligned with the fuel injector, the fuel injector is not blocked by the differential housing.

15. The method of claim 11, further comprising determining that a housing bore defined by the differential housing is misaligned with an injector configured to provide lubrication to the moving internal component through the housing bore, wherein the differential housing is rotated in response to determining that the housing bore is misaligned with the injector.

16. The method of claim 11, wherein the rotational position of the differential housing is determined via a mark fixed to the differential housing.

17. The method according to claim 16, wherein, The rotational position of the differential housing is sensed by a position sensor, and the rotational position of the differential housing is determined based on the proximity of the marker to the position sensor.

18. The method of claim 11, wherein the differential housing at least partially encloses the two side gears.

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