Shaft speed sensing system

Abstract

A drivetrain associated with a vehicle includes a shaft that rotates about an axis of rotation. The shaft is connected to a gear set. The drivetrain includes a sensor target that is connected to the gear set and rotates with the gear set. The sensor target includes at least one target. The drivetrain includes a sensor that is spaced apart from the sensor target by a gap. The sensor is configured to observe the at least one target of the sensor target to determine a rotational speed of the shaft.

Description

Technical Field

[0001] This technical field generally relates to sensing systems for the speed of rotating shafts, and particularly to sensing systems for the speed of rotating shafts related to vehicle transmissions. Background Technology

[0002] Taking a vehicle as an example, a transmission transfers power from the engine to the vehicle's wheels at selectable gear ratios. In the case of an automatic transmission, the transmission may include a torque converter, which transmits torque from the engine's output shaft to the transmission's input shaft. Due to the torque converter, the input shaft can rotate at a different speed than the engine's output shaft. Typically, the transmission switches between different gear ratios based on the input shaft's rotational speed. To determine the input shaft's rotational speed, sensors can be used to observe the input shaft as it rotates. However, due to the structure of the transmission, it can be difficult to observe the input shaft while it is rotating.

[0003] Therefore, it is necessary to provide a system for shaft speed sensing, enabling the sensor to observe the rotation of a shaft, such as an input shaft associated with a transmission, to determine the shaft speed. Furthermore, other desirable features and characteristics of the invention will become apparent from the following detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background. Summary of the Invention

[0004] According to various embodiments, a drivetrain associated with a vehicle is provided. The drivetrain includes a shaft configured to rotate about a rotation axis. The shaft is connected to a gear set. The drivetrain includes a sensor target connected to the gear set and configured to rotate with the gear set. The sensor target includes at least one target. The drivetrain includes a sensor spaced apart from the sensor target by a gap. The sensor is configured to observe at least one target of the sensor target to determine the rotational speed of the shaft.

[0005] The sensor target includes a body and a target flange, with at least one target defined within the target flange. The target flange extends axially from the body and forms the outer edge of the sensor target. The gear set is a planetary gear set, including a bracket connecting the planetary gears and a shaft. The body includes at least one connecting flange extending radially from the bracket to be connected to the planetary gear set. The at least one target includes a plurality of windows defined by the sensor target and evenly spaced around the outer edge of the sensor target. The sensor is a reverse-biased tunneling magnetoresistive sensor, and the sensor target does not contain one or more magnets. The sensor target is composed of an ferrous material.

[0006] A vehicle is further provided according to various embodiments. The vehicle includes a transmission system comprising a shaft configured to rotate about a rotation axis. The shaft includes a planetary gear set connected to the shaft and configured to rotate with the shaft. The vehicle includes a shaft sensing system configured to observe the rotation of the shaft about the rotation axis. The shaft sensing system includes a sensor target connected to the planetary gear set associated with the shaft. The sensor target includes at least one window and does not have one or more magnets. The shaft sensing system includes a reverse-biased tunneling magnetoresistive sensor spaced apart from the sensor target by a gap. The reverse-biased tunneling magnetoresistive sensor is configured to generate a magnetic field and observe at least one window of the sensor target to determine the rotational speed of the shaft.

[0007] The shaft is the input shaft of the transmission system. A non-ferrous torque transmission housing is placed within the gap between the reverse-biased tunneling magnetoresistive sensor and the sensor target, and the non-ferrous torque transmission housing is configured to rotate independently of the shaft. The reverse-biased tunneling magnetoresistive sensor is connected to the housing associated with the transmission system, and extends along a sensor shaft approximately perpendicular to the axis of rotation of the shaft. The sensor target includes a body and a target flange, and defines at least one window in the target flange. The target flange extends axially from the body and forms the outer edge of the sensor target. The body includes at least one connecting flange that extends radially from the body and connects to a bracket of a planetary gear set, the bracket of which connects to the planetary gear set and the shaft. The at least one window includes a plurality of windows defined by the sensor target and evenly spaced around the outer edge of the sensor target. The sensor target is composed of a ferrous material.

[0008] A vehicle including a drivetrain is also provided. The drivetrain includes a shaft configured to rotate about an axis of rotation. The shaft includes a planetary gear set having a bracket connected to the planetary gears and the shaft. The vehicle includes a shaft sensing system configured to observe the rotation of the shaft about the axis of rotation. The shaft sensing system includes a sensor target connected to the bracket of the planetary gear set and configured to rotate with the bracket of the planetary gear set. The sensor target is made of an ferrous material. The sensor target includes a body forming the outer edge of the sensor target and a target flange. The target flange extends axially from the body and defines a plurality of windows evenly spaced around the outer edge of the target flange. The sensor target does not have one or more magnets. The shaft sensing system includes a reverse-biased tunneling magnetoresistive sensor spaced apart from the sensor target by a gap. The reverse-biased tunneling magnetoresistive sensor is configured to generate a magnetic field and observe the plurality of windows of the sensor target to determine the rotational speed of the shaft.

[0009] A non-ferrous torque transmission housing is placed within the gap between the reverse-biased tunneling magnetoresistive sensor and the sensor target, and the non-ferrous torque transmission housing is configured to rotate independently of the shaft. The reverse-biased tunneling magnetoresistive sensor is connected to the housing associated with the drive system, and the reverse-biased tunneling magnetoresistive sensor extends along a sensor shaft approximately perpendicular to the axis of rotation. The body includes at least one connecting flange extending radially from the body and connected to the shaft. Attached Figure Description

[0010] Example embodiments will be described below with reference to the accompanying drawings, wherein similar numbers denote similar elements, and wherein:

[0011] Figure 1 This is a functional block diagram illustrating a vehicle including a drive system having an axle sensing system according to various embodiments;

[0012] Figure 2 yes Figure 1 A three-dimensional view of the transmission system, in which the shaft sensing system is configured inside the housing of the transmission system;

[0013] Figure 3 It is along Figure 2 The 3-3 line is cut off Figure 2 A cross-sectional view of the transmission system;

[0014] Figure 4 It is taken from Figure 3 The four places on the top Figure 3 Detailed diagram of the transmission system;

[0015] Figure 5 It is a front view of the sensor target of the axis sensing system; and

[0016] Figure 6 From Figure 5 A side view of the sensor target of the axis sensing system as observed from a V-angle. Detailed Implementation

[0017] The following detailed description is exemplary in nature and is not intended to limit the invention and its use. Furthermore, there is no intention to be bound by any express or implied theory presented in the preceding background, summary of the invention, or the following detailed description. Herein, the term "module" refers to any hardware, software, firmware, electronic control components, processing logic, and / or processor device, individually or in any combination, including but not limited to: application-specific integrated circuits (ASICs), electronic circuits, processors (shared, dedicated, or grouped), and memory executing one or more software or firmware programs, combinational logic circuits, and / or other suitable components providing the said functionality.

[0018] Embodiments of the present invention may be described herein in terms of functional and / or logical block components and various processing steps. It should be recognized that such block components can be implemented by any number of hardware, software, and / or firmware components configured to perform specific functions. For example, embodiments of the present invention may employ various integrated circuit components, such as memory elements, digital signal processing elements, logic elements, lookup tables, etc., which can perform various functions under the control of one or more microprocessors or other control devices. Furthermore, those skilled in the art will understand that embodiments of the present invention can be practiced in conjunction with any number of systems, and the axis sensing system described herein is merely an exemplary embodiment of the invention.

[0019] For the sake of brevity, conventional techniques related to signal processing, data transmission, signals, control, machine learning models, radar, lidar, image analysis, and other functional aspects of the system (and individual operating components of the system) may not be described in detail herein. Furthermore, the connecting lines shown in the various figures included herein are intended to illustrate examples of functional relationships and / or physical connections between various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in embodiments of the invention.

[0020] In this document, the term "axial" refers to a direction that is substantially parallel or coincident with the centerline of an axis of rotation, axis of symmetry, or one or more components. For example, in the case of a cylinder or disk having a centerline and at both ends or opposite faces that are substantially circular, the "axial" direction can refer to a direction that extends substantially parallel to the centerline between the opposite ends or faces. In certain cases, the term "axial" can be used for non-cylindrical (or non-radially symmetrical) components. For example, the "axial" direction of a rectangular housing containing a axis of rotation can be considered as a direction that is substantially parallel or coincident with the axis of rotation of the shaft. Furthermore, the term "radial" as used herein can refer to the direction or component relationship of a line extending outward from a shared centerline, axis, or similar reference line, such as in a plane of a cylinder or disk perpendicular to the centerline or axis. In certain cases, even if one or both components may not be cylindrical (or non-radially symmetrical), the components can be considered as "radially" aligned. Moreover, the terms "axial" and "radial" (and any derivatives) can include directional relationships other than precise alignment with the true axial and radial aspects (e.g., oblique), provided that such relationships are primarily in their respective nominal axial or radial directions. Furthermore, as used herein, the term “approximately” indicates within 5% to indicate manufacturing tolerances.

[0021] refer to Figure 1 According to various embodiments, a shaft sensing system, typically shown as 100, is associated with vehicle 10. Typically, shaft sensing system 100 observes the speed of a rotating shaft, such as the input shaft 106 of transmission system 22, and generates sensor signals for controlling transmission system 22 of vehicle 10. Figure 1 As shown, vehicle 10 typically includes a chassis 12, a body 14, front wheels 16, and rear wheels 18. The body 14 is mounted on the chassis 12 and essentially surrounds the components of vehicle 10. The body 14 and chassis 12 may together form a frame. Wheels 16 and 18 are rotatably connected to their respective corners of the chassis 12 near the body 14.

[0022] In various embodiments, vehicle 10 is an autonomous or semi-autonomous vehicle. It is understood that the shaft sensing system 100 can be implemented in other non-autonomous systems and is not limited to this embodiment. Vehicle 10 is described as a passenger vehicle in the illustrated embodiment, but it should be understood that any other vehicle, including motorcycles, trucks, SUVs, RVs, boats, aircraft, etc., may also be used.

[0023] As shown in the figure, vehicle 10 typically includes a propulsion system 20, a drivetrain 22, a steering system 24, a braking system 26, a sensor system 28, an actuator system 30, and at least one controller 34. In various embodiments, the propulsion system 20 may include an internal combustion engine, an electric motor such as a traction motor, and / or a fuel cell propulsion system. The propulsion system 20 typically has an output shaft or crankshaft 102 connected to the drivetrain 22. The drivetrain 22 is configured to transmit power received from the crankshaft 102 of the propulsion system 20 to the wheels 16, 18 according to an optional gear ratio.

[0024] Braking system 26 is configured to provide braking torque to wheels 16, 18. In various embodiments, braking system 26 may include friction braking, brake-by-wire braking, regenerative braking systems, such as electric motors and / or other suitable braking systems. Steering system 24 affects the position of wheels 16 and / or 18. Although described for illustrative purposes as including a steering wheel, in some embodiments contemplated within the scope of the invention, steering system 24 may not include a steering wheel.

[0025] Sensor system 28 includes one or more sensing devices 40a-40n that sense the observable conditions of the external and / or internal environment of vehicle 10. In various embodiments, sensing devices 40a-40n include, but are not limited to, radar (e.g., long-range, medium-range-short-range), lidar, global positioning system, optical cameras (e.g., forward, 360-degree, rearward, lateral, stereo, etc.), thermal (e.g., infrared) cameras, ultrasonic sensors, odometer sensors (e.g., encoders), and / or other sensors that may be relevant to the systems and methods according to this subject matter.

[0026] The actuator system 30 includes one or more actuator devices 42a-42n that control one or more vehicle features, such as, but not limited to, the propulsion system 20, the transmission system 22, the steering system 24, and the braking system 26. In various embodiments, the vehicle 10 may also include... Figure 1 Vehicle interior and / or exterior features not specified in the description, such as various doors, trunk and cabin features, such as air, music, lighting, touchscreen display components (e.g., components used in connection with navigation systems), etc.

[0027] The controller 34 includes at least one processor 44 and a computer-readable storage device or media 46. The processor 44 can be any custom or commercial processor, central processing unit (CPU), graphics processing unit (GPU), application-specific integrated circuit (ASIC) (e.g., a custom ASIC implementing a neural network), field-programmable gate array (FPGA), an auxiliary processor among a plurality of processors associated with the controller 34, a semiconductor-based microprocessor (in the form of a microchip or chipset), and any combination thereof, or any device generally used for executing instructions. The computer-readable storage device or media 46 can include, for example, volatile and non-volatile storage in read-only memory (ROM), random access memory (RAM), and keep-alive memory (KAM). KAM is persistent or non-volatile memory that can be used to store various operational variables when the processor 44 is powered off. The computer-readable storage device or media 46 can be implemented using any of many known storage devices, such as PROMs (programmable read-only memories), EPROMs (electrical PROMs), EEPROMs (electrically erasable PROMs), flash memory, or any other electrical, magnetic, optical, or combined storage device capable of storing data, some of which represent executable instructions used by the controller 34 in the control system of the vehicle 10. The controller 34 communicates with the shaft sensing system 100 via a communication medium that facilitates the transmission of data, power, etc.

[0028] refer to Figure 2 A perspective view of the transmission system 22 is shown. According to various embodiments, the transmission system 22 is a ten-speed automatic transmission. The transmission system 22 includes a torque converter 104 connected to the crankshaft 102 of the propulsion system 20. The torque converter 104 enables the propulsion system 20 to move independently of the transmission system 22 and uses the torque received from the crankshaft 102 to drive the input shaft 106 of the transmission system 22. Therefore, due to the torque converter 104, the crankshaft 102 of the propulsion system 20 can rotate at a speed different from that of the input shaft 106. A shaft sensing system 100, disposed within the housing 60 of the transmission system 22, is capable of determining the rotational speed of the input shaft 106 to ensure proper selection of gears in the transmission system 22.

[0029] refer to Figure 3A cross-sectional view of the transmission system 22 is shown. The transmission system 22 includes multiple planetary gear sets 117, 119, 120, 121 and multiple clutches 130, which cooperate to provide power to wheels 16 and / or 18. Figure 1 In one example, the transmission system 22 includes four planetary gear sets 117, 119, 120, and 121 and six clutches 130. The planetary gear sets 117, 119, 120, and 121 cooperate with the clutches 130 of the transmission system 22 to transmit torque from the crankshaft 102 to drive the wheels 16 and / or 18. In this example, the shaft sensing system 100 is associated with one of the planetary gear sets 117, 119, 120, and 121 to determine the rotational speed and direction of the input shaft 106.

[0030] In one example, the shaft sensing system 100 includes a sensor 110 and a sensor target 112. Due to the configuration and arrangement of the drive system 22, and referring to... Figure 4 The distance D between sensor 110 and sensor target 112 is approximately 5.77 mm to approximately 8.55 mm. Distance D defines an air gap 114 between sensor 110 and sensor target 112. Furthermore, a torque transmission housing 116 is disposed within the air gap 114 between sensor 110 and sensor target 112. The torque transmission housing 116 is cylindrical and surrounds a portion of the transmission system 22. The torque transmission housing 116 rotates independently of sensor target 112. The torque transmission housing 116 is composed of a non-ferrous metal or metal alloy, including but not limited to aluminum. In this example, sensor 110 observes sensor target 112 through the torque transmission housing 116. The torque transmission housing 116 creates a metallic barrier between sensor 110 and sensor target 112. The torque transmission housing 116 is connected at one end 116a to the planet 117a of the planetary gear set 117, and at the other end 116b to the planet 119a of the planetary gear set 119. The torque transmission housing 116 transmits torque from the planetary gear set 117 to the planetary gear set 119.

[0031] Sensor 110 observes sensor target 112 and generates a sensor signal based on the observation. In one example, sensor 110 is a solid-state device that detects changes in magnetic flux on sensor 110. In this example, sensor 110 is a reverse-biased tunnel magnetoresistive (TMR) sensor. Sensor 110 generates a sensor signal based on the observed changes in magnetic flux. Since sensor 110 is reverse-biased, sensor 110 includes one or more magnets that generate a magnetic field. In one example, sensor 110 includes one or more rare-earth magnets to generate the magnetic field. Sensor 110 communicates with controller 34 via a communication medium to transmit sensor signals to and receive power from controller 34. Based on the sensor signals, controller 34 is configured to determine the rotational speed and direction of input shaft 106. Alternatively, sensor 110 may include a processor and storage medium that can locally determine the rotational speed and direction of input shaft 106 at sensor 110 and can transmit that determination to controller 34. Sensor 110 is connected to gearbox 118 associated with drivetrain 22. Typically, sensor 110 is connected to gearbox 118 to extend along axis SA, which is approximately perpendicular to axis IA of input shaft 106. Figure 3 The input shaft 106 rotates about axis IA, which is the axis of rotation of the input shaft 106. As a portion of the sensor target 112 rotates relative to the sensor 110, the sensor 110 observes changes in magnetic flux. Typically, the sensor housing of the sensor 110 is configured such that the minimum thickness of the sensor housing is positioned between the sensor 110 and the sensor target 112. It should be noted that although the sensor 110 is described herein as a sensor incorporating reverse-biased tunnel magnetoresistive (TMR), different types of sensors may be used with respect to the sensor target 112 depending on the distance D between the sensor 110 and the sensor target 112.

[0032] refer to Figure 3 Sensor target 112 is connected to planetary gear set 120. Planetary gear set 120 can rotate independently of planetary gear sets 117 and 119. Planetary gear set 120 includes a carrier 122, a ring gear 123, a sun gear 124, and one or more planetary gears 125. Sensor target 112 is connected to carrier 122 by one or more rivets 127, however, any suitable mechanical fastener can be used. Carrier 122 is connected to each planetary gear 125 by one or more mechanical fasteners such as bolts. Carrier 122 is also connected to input shaft 106 via rack 128. Carrier 122 rotates at the same speed as input shaft 106. Therefore, the rotation of carrier 122 and sensor target 112 connected to carrier 122 is directly proportional to the rotational speed of input shaft 106.

[0033] Sensor 110 observes sensor target 112 to determine the rotational speed and direction of input shaft 106. (Reference) Figure 5 The image shows a front view of sensor target 112. Sensor target 112 is annular and made of ferrous metal or a metal alloy, such as steel 1010. It is important to note that since sensor 110 is a reverse-biased tunneling magnetoresistive sensor, sensor target 112 is made of ferrous material but does not include or contain one or more magnets, which provides weight reduction and reduces manufacturing complexity. In this respect, since sensor target 112 does not include one or more magnets to generate a magnetic field, sensor target 112 can be manufactured by stamping, casting, additive manufacturing, etc. Typically, sensor target 112 is formed as a single piece or monolithic sheet. The thickness of sensor target 112 is T( Figure 4 In one example, the thickness T is approximately 1.0 mm to approximately 3.0 mm.

[0034] Sensor target 112 includes at least one or more connecting flanges 150, a body 152, and a target flange 154. Sensor target 112 also defines a central target hole 156, enabling sensor target 112 to be positioned around input shaft 106. The connecting flanges 150 extend radially inward from the body 152 to the central target hole 156. In this example, sensor target 112 has five connecting flanges 150 spaced approximately equal to the inner diameter 112a of sensor target 112; however, sensor target 112 can have any number of connecting flanges 150. In this example, sensor target 112 is asymmetrical with respect to its central axis CA. The central axis CA is coaxial with the axis IA of input shaft 106. Figure 3 The connecting flange 150 includes pilot holes 158 and rivet holes 159. Each pilot hole 158 assists in positioning the sensor target 112 on the planetary gear set 120. Figure 5 Each rivet hole 159 receives the corresponding rivet 127. Figure 5 ), to connect sensor target 112 to planetary gear set 120 ( Figure 5 ).

[0035] The body 152 defines an inner diameter 112a of the sensor target 112 and extends to an outer diameter 112b. In one example, the body 152 includes a plurality of recessed portions 160 defined between the inner diameter 112a and the outer diameter 112b. In one example, the recessed portions 160 are defined at a distance Di from the inner diameter 112a and a distance Do from the outer diameter 112b. In this example, the distances Di are different and greater than the distance Do, causing the recessed portions 160 to be radially offset toward the outer diameter 112b. The recessed portions 160 are spaced apart from the outer edge of the body 152. The recessed portions 160 result in the body 152 having an undulating surface around a portion of the outer edge of the body 152. Typically, alignment portions 162 are defined between adjacent portions of the recessed portions 160, with one of the recessed portions 160 and one of the alignment portions 162 alternating on the outer edge of the portion of the body 152. In this example, a simplified reference is provided. Figure 3 Each recessed portion 160 is misaligned or non-coplanar with a portion of the surface 164 of the body 152 of the sensor target 112, while the aligned portion 162 is approximately coplanar, horizontal, or flush with the surface 164. The recessed portions 160 alter the natural frequency of the sensor target 112, which helps reduce vibration. In one example, the sensor target 112 is attached to a bracket 122 for configuration between a transmission torque transmission housing 116 and a clutch housing 166. The clutch housing 166 is made of a non-ferrous metal or metal alloy, including but not limited to aluminum. The clutch housing 166 partially encloses one of the clutches 130 associated with the transmission system 22.

[0036] The target flange 154 is connected to or integrally formed with the body 152 at an outer diameter of 112b. According to... Figure 5 At the outer diameter 112b of the sensor target 112, a target flange 154 extends axially outward from the body 152. Therefore, the target flange 154 forms the outer edge of the sensor target 112. The target flange 154 has a first target end 154a connected to or integrally formed with the body 152, and an opposing second target end 154b defining the tail end of the target flange 154. In one example, the body 152 is folded at a fold 155 to form the target flange 154. The target flange 154 includes a plurality of targets 170. In one example, the targets 170 include a plurality of windows defining a non-ferrous region of the target flange 154; however, it should be understood that the targets 170 may include a plurality of spaced teeth to define the non-ferrous region of the target flange 154. In this example, the target flange 154 includes approximately 20 to approximately 50 windows, and in one example, approximately 40 windows. Generally, more targets 170 increase the resolution of the sensor 110.

[0037] Targets 170 are spaced around the outer edge of target flange 154, and therefore around the outer edge of sensor target 112. Targets 170 are typically rectangular, each with a different width W that is less than its length L. In one example, the width W is between approximately 5.8 mm and approximately 6.8 mm, and the length L is between approximately 9.5 mm and approximately 10.5 mm. In this example, each target 170 has a chamfer or fillet 174 that connects the walls of the target 170 to each other. However, it should be noted that targets 170 can have any desired shape to define a non-ferrous area within target flange 154. Figure 3 The target flange 154 defines the target 170, with the center of each target 170 coaxial with the sensor axis SA of the sensor 110. This ensures that the target 170 is observed by the sensor 110 even when the sensor target 112 moves axially relative to the sensor 110 (in the direction parallel to the rotation axis IA of the input shaft 106). Furthermore, the width W and length L of each target 170 are predetermined to ensure that the target 170 is observed by the sensor 110 even when the sensor target 112 moves axially relative to the sensor 110 (in the direction parallel to the rotation axis IA of the input shaft 106).

[0038] Target 170 can be formed simultaneously during the formation of sensor target 112 via additive manufacturing or casting, or it can be formed in a secondary operation via stamping or machining. Since targets 170 are spaced apart around the outer edge or periphery of target flange 154, the ferrous portions 176 of target flange 154 are defined between adjacent targets 170. In one example, targets 170 are uniformly spaced around the outer edge of target flange 154. One of the ferrous portions 176 of target flange 154 alternates with one of the targets 170 around the outer edge or periphery of target flange 154. By providing a window or target 170 that does not contain ferrous material, sensor 110 observes the change in magnetic flux caused by the non-ferrous metal targets 170 passing through or in front of sensor 110 as target flange 154 rotates with input shaft 106. Typically, since the number of targets 170 around the outer edge of the target flange 154 or the number of targets 170 per cycle is known, the controller 32 is configured to determine the rotational speed and direction of the input shaft 106 based on the magnitude of the change in magnetic flux observed within a predetermined time unit (caused by the targets 170 passing through the sensor 110).

[0039] In one example, to assemble sensor target 112 onto input shaft 106, refer to... Figure 3Sensor target 112 is formed to include target 170. With planetary gear sets 117, 119, 120, 121 connected to input shaft 106, sensor target 112 is positioned around input shaft 106. Rivet 127 is inserted into hole 159 of connecting flange 150 to connect sensor target 112 to bracket 122 of planetary gear set 120. Sensor 110 is attached to transmission housing 118, aligning sensor axis SA with the center of one of targets 170 on target flange 154, positioning sensor 110 in communication with controller 34. Torque converter 104 is connected to input shaft 106. The remainder of transmission system 22 is assembled, and transmission system 22 is installed in vehicle 10, with crankshaft 102 ( Figure 2 It is connected to torque converter 104.

[0040] As the shaft sensing system 100 is assembled and installed within the vehicle 10, the sensor 110 generates a magnetic field during the operation of the vehicle 10. When the propulsion system 20 rotates the crankshaft 102, the torque converter 104 adjusts the torque of the crankshaft 102 to drive the input shaft 106. As the input shaft 106 rotates, the carrier 122 of the planetary gear set 120 rotates with the input shaft 106 at the same speed. When the sensor target 112 is connected to the carrier 122 of the planetary gear set 120, the sensor target 112 rotates at the same speed as the input shaft 106. As the sensor target 112 rotates, the sensor 110 observes the change in magnetic flux caused by the target 170 of the target flange 154 passing through the torque transmission housing 116. Typically, when the target 170 passes through the sensor 110, the magnetic flux changes, causing the sensor 110 to generate a pulse. Based on the number of pulses received per predetermined unit time, which is given by the known number of targets 170 in each cycle, the controller 34 determines the rotational speed of the input shaft 106.

[0041] Therefore, the shaft sensing system 100 enables the sensor 110 to indirectly observe the rotation of the input shaft 106 via the planetary gear set 120 and generate a sensor signal that effectively indicates the speed and direction of the input shaft 106. By providing a reverse-biased tunnel magnetoresistive sensor 110, the sensor target 112 does not need to include a magnet or be unmagnetized, which reduces the weight of the sensor target 112 and also reduces the manufacturing complexity associated with the sensor target 112. Furthermore, the shaft sensing system 100 can accurately detect the direction and rotational speed of the input shaft 106 even through the torque transmission housing 116 and the atmospheric gap 114. In addition, by providing a magnetless sensor target 112, the eddy currents generated within the torque transmission housing 116 are reduced, which reduces a significant amount of energy lost as heat. The reduction in eddy currents and energy loss can also improve the fuel efficiency of the vehicle 10. Furthermore, by providing a magnetless sensor target 112, the sensor target 112 can be more robust and durable during the operation of the vehicle 10.

[0042] It should also be understood that the exemplary embodiments or groups of exemplary embodiments are merely examples and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the detailed description above will provide those skilled in the art with convenient ways to implement the exemplary embodiments or groups of exemplary embodiments. It should be understood that various changes can be made to the function and arrangement of the elements without departing from the scope of the invention as defined in the appended claims and their legally equivalent statements.

Claims

1. A drivetrain associated with a vehicle, comprising: A shaft configured to rotate about an axis of rotation, said shaft being connected to a gear set; A non-ferrous housing configured to rotate independently of the axis; A sensor target, connected to and configured to rotate with the gear set, the sensor target comprising at least one target; and A sensor separated from a sensor target by a gap, the non-ferrous housing being located within the gap between the sensor and the sensor target, and the sensor being configured to observe at least one of the sensor target to determine the rotational speed of the shaft.

2. The transmission system according to claim 1, wherein the sensor target comprises a body and a target flange, and at least one target defined in the target flange.

3. The transmission system according to claim 2, wherein the target flange extends axially from the body and forms the outer edge of the sensor target.

4. The transmission system of claim 2, wherein the gear set is a planetary gear set, comprising a bracket connected to the planetary gear set and a shaft, the body comprising at least one connecting flange extending radially from the body of the bracket to be connected to the planetary gear set.

5. The transmission system of claim 1, wherein the at least one target comprises a plurality of windows defined by the sensor target and spaced evenly around the outer edge of the sensor target.

6. The drive system of claim 1, wherein the sensor is a reverse bias tunnel magnetoresistive sensor, and the sensor target has no one or more magnets.

7. The transmission system according to claim 6, wherein the sensor target is composed of an iron-containing material.

8. A vehicle comprising: The transmission system of claim 1, wherein the gear set is a planetary gear set, the planetary gear set having a bracket connected to the planetary gears and the shaft, and the shaft is the input shaft of the transmission system; A sensor target is attached to and configured to rotate with the planetary gear set's bracket. The sensor target is made of an ferrous material and includes a body and a target flange forming the outer edge of the sensor target. The target flange extends axially from the body. The at least one target is a plurality of windows defined in the target flange and spaced evenly around the outer edge of the target flange. The sensor target does not contain one or more magnets. The sensor is a reverse-biased tunneling magnetoresistive sensor, separated from the sensor target by a gap. The reverse-biased tunneling magnetoresistive sensor is configured to generate a magnetic field and observe multiple windows of the sensor target to determine the rotational speed of the shaft.

9. The vehicle of claim 8, wherein the nonferrous torque transmission housing is located within the gap between the reverse bias tunnel magnetoresistive sensor and the sensor target, and the nonferrous torque transmission housing is configured to rotate independently of the shaft.

10. The vehicle of claim 8, wherein the reverse bias tunnel magnetoresistive sensor is connected to a housing associated with the drivetrain, the reverse bias tunnel magnetoresistive sensor extends along a sensor axis approximately perpendicular to the axis of rotation of the shaft, and the body includes at least one connecting flange extending radially from the body to be connected to the shaft.

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