Flexible position of an electric connector of a drive unit

Abstract

Drive unit arrangement (60) comprising: a housing (62) extending axially about a longitudinal axis; a control board (68) with a main printed circuit board section (72) covered by the housing (62), a first printed circuit board extension segment (82) and a second printed circuit board extension segment (80); at least one logic connector (90) arranged on the first printed circuit board extension segment (82); and a power connector (94) arranged on the second printed circuit board extension segment (82), characterized in that the first printed circuit board extension segment (82) extends radially away from the longitudinal axis and out of the housing (62) and is not covered by the housing (62), and that the second printed circuit board extension segment (80) extends radially away from the longitudinal axis and out of the housing (62) and is not covered by the housing (62).

Description

FIELD OF THE INVENTIONThe present disclosure relates to steering assembly assemblies for vehicles, and more particularly to such assemblies having flexible locations for electrical connectors.BACKGROUNDA vehicle often includes an electric power steering (EPS) system to assist a driver of the vehicle in steering the vehicle. The EPS system uses sensors to sense a position and torque of a steering column and provide a signal to an electric motor to allow the electric motor to provide additional torque to assist the driver in steering the vehicle. The additional torque provided to assist the driver in steering the vehicle may vary depending on vehicle characteristics, driving conditions, road condition, and the like.The EPS system may use a controller to receive signals from sensors, analyze the signals, and control the electric motor. The control board is connected to a motor housing via a shell, which may be referred to herein as a connection plate. Collectively, these components may be referred to as a power plant assembly that provides electrical power to one or more functions associated with the steering system.Power unit assemblies often include a printed circuit board (PCB) having electrical connections in electrical communication therewith. Typically, the printed circuit board and electrical connector architecture allows only a single alignment, and thus location, of the connectors and thus does not provide flexibility in layout design.The document DE 10 2011 002 006 A1 discloses a drive unit for a motorized device with a housing, a control board and a first and second plug. The document DE 11 2018 005 481 T5 discloses a motor with a circuit board, a cover and a connector.SUMMARY OF THE DISCLOSUREIt is an object of the present invention to provide a more economical, more robust and versatile power plant assembly.This object is achieved by a drive unit arrangement according to claim 1.A further aspect of the disclosure relates to an electric power steering (EPS) system according to claim 8.BRIEF DESCRIPTION OF THE DRAWINGSThe subject matter which is considered to be the invention is particularly pointed out and distinctly claimed in the claims at the end of the specification. The foregoing and other features and advantages of the invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. 1 schematically shows an electric power steering (EPS) system for a vehicle; FIG. 2 is a bottom perspective view of a power plant assembly; FIG. 3 is a top perspective view of the power plant assembly; FIG. 4 is an end view of a prime mover assembly; FIG. 5 is a cross-sectional view of the power plant assembly; FIG. 6 is a partially disassembled view of the power unit assembly; FIG. 7 is another partially disassembled view of the power unit assembly; FIG. 8 is another partially disassembled view of the power unit assembly; FIGS. 9-11 show an example configuration of the power plant assembly with an external connector; FIGS. 12-14 show another example configuration of the power plant assembly with an external connector; FIGS. 15-17 show an example configuration of the power plant assembly with an internal connector; FIGS. 18-20 show another example configuration of the power plant assembly with an internal connector; and FIG. 21 shows the power plant assembly according to another example configuration.DETAILED DESCRIPTIONWith reference to the figures, embodiments of the disclosure are described herein without limiting the same. In particular, a manual power plant assembly for an electric power steering (EPS) system is disclosed herein. Although illustrated and described in connection with a pillar EPS system, it should be understood that other types of EPS systems (e.g., racks) may benefit from the embodiments disclosed herein. Moreover, the depicted steering system includes a mechanical connection from the steering input device to the steering gear, but it is understood that steer-by-wire systems may also benefit from the embodiments disclosed herein. Therefore, the illustrated embodiment is not limiting to the particular application in which the manual power plant assembly may be used.FIG. 1 is an exemplary embodiment of an electric power steering (EPS) system 40 suitable for implementing the disclosed embodiments. The steering mechanism 36 is a rack and pinion system and includes a rack (not shown) in a housing 50 and a pinion (also not shown) located below a gear housing 52. When the operator input, hereinafter referred to as a steering wheel 26 (e.g., a hand wheel or the like) is turned, the upper steering shaft 29 rotates, and the lower steering shaft 51 connected to the upper steering shaft 29 via the universal joint 34 rotates the pinion. The rotation of the pinion moves the rack, moves tie rods 38 (only one is shown), which in turn move steering knuckles 39 (only one is shown) that turn steerable wheel or wheels 44 (only one is shown).The electric power steering assist is provided by the control device generally designated by reference numeral 24 and includes the controller 16 and an electric machine 19, which may be a permanent magnet synchronous motor, a permanent magnet DC motor, a switched reluctance motor, or any other type of motor, and will be referred to herein as motor 19. The controller 16 is powered from the vehicle power supply 10 via a line 12. The controller 16 receives information from sensors related to various operating conditions and / or inputs of the EPS system 40, examples of which are shown and described below.When the steering wheel 26 is turned, a torque sensor 28 detects the torque applied to the steering wheel 26 by the vehicle operator. The torque sensor 28 may include a torsion bar (not shown) and a variable resistance sensor (also not shown) that outputs a variable torque signal 18 to the controller 16 depending on the amount of torsion of the torsion bar. Although this is one type of torque sensor, any other suitable torque measurement device used with known signal processing techniques is sufficient. In response to the various inputs, the controller sends a command 22 to the motor 19 which provides torque assist for vehicle steering via a worm 47 and worm wheel 48. A feedback signal 21 is fed back from the motor 19 to the controller 16.It should be noted that while the disclosed embodiments are described with reference to motor control for electric steering applications, it should be appreciated that these references are illustrative only and the disclosed embodiments may be applied to any motor control application that uses an electric motor, e.g., steering, valve control, and the like. Moreover, the references and descriptions herein may be applied to many forms of parameter sensors, including, but not limited to, torque, position, speed, and the like. It should also be noted that references herein to electric machines, including, but not limited to, motors, hereinafter for brevity and simplicity, reference is made only to motors without limitation.In the illustrated control system 24, the controller 16 uses the torque, position, and speed, and the like, to calculate one or more commands to provide the required output power. The controller 16 is disposed in communication with the various systems and sensors of the engine control system. The controller 16 receives signals from each of the system sensors, quantify the information received, and in response, provides one or more output command signals, in this case, e.g., to the motor 19. the controller 16 is configured to develop the required voltage(s) from an inverter (not shown), which may optionally be integrated into the controller 16 and is referred to herein as controller 16, such that upon application to the motor 19, the desired torque or position is generated. Since these voltages are related to the position and speed of the motor 19 and the desired torque, the position and / or speed of the rotor and the torque applied by an operator are determined. A position sensor is connected to the steering shaft 51 to detect the angular position. The encoder can detect the rotational position based on optical detection, magnetic field fluctuations or other methods. Typical position sensors are potentiometers, resolvers, synchros, encoders and the like, as well as combinations of at least one of the above. The position transducer outputs a position signal 20 which indicates the angular position of the steering shaft 51 and thus that of the motor 19.As shown in FIGS. 2-8, a power plant assembly is illustrated and generally designated by reference numeral 60. As described above, the power plant assembly 60 is an assembly that powers one or more systems of a vehicle steering system. Although the power plant assembly is substantially illustrated and described as powering the EPS system 40, it should be appreciated that the power plant assembly 60 may also be used to power other electrical systems.The power plant assembly includes a housing 62 mounted to a heat sink shell 64 to enclose a portion of a control board 68 and a motor shaft 70 that drives the EPS system 40. The control board 68 includes a circuit board main portion 72 (FIGS. 5 and 6 ) covered by the housing 62. As shown, the housing 62 includes a body portion 74, an end surface 76, and a plurality of flange portions 78 located at an end of the body portion 74 opposite the end surface 76. The body portion 74 includes at least one substantially cylindrical portion, but may also include one or more steps as shown in the illustrated embodiment.The flange portions 78 each include one or more apertures for receiving mechanical fasteners for coupling the housing 62 to the heat sink shell 64 and / or for receiving positioning pins or the like. The periphery of the body portion 74 and the flange portions 78 cover the circuit board main portion 72 of the control board 68 when the housing 62 is coupled to the heat sink shell 64. However, the heat sink shell 64 and the control board 68 each include substantially corresponding segments that extend radially outward to positions outside the housing 62. In other words, the heat sink shell 64 includes one or more extended shell segments 80 and the control board 68 includes one or more circuit board extension segments 82, each of which extends to a distance not covered by the housing 62. These circuit board extension segments 80, 82 (FIG. 5 ) are therefore located outside the housing 62.The circuit board extension segments 80, 82 provide additional connection points that can be aligned depending on the specifications of the overall system. Thus, the entire power plant assembly 60 is adjustable to allow for various orientations that are advantageous to the system. This is in contrast to power plant assemblies that cover all connection points within the housing. In the illustrated embodiments, the first connection points are generally designated by reference numeral 90 and are partially covered with a first connector cover 92. The first connection points 90 are logic connectors that form a logic header. A second terminal 94 is a power source connector and is partially covered with a second connector cover 96. The second connection point 94 is a power supply terminal that is a power supply header.FIGS. 9-11 show the power plant assembly 60 coupled to an EPS system housing 100 (also referred to as an EPS housing below) according to a first orientation with an external main circuit board (MSB) 99. In the illustrated embodiment, the connection points 90, 94 are directed toward the housing 62. Arrows 98 represent the rotation of the prime mover assembly 60. In other words, the angular position of the prime mover assembly 60 may be changed to match the orientation most desirable for the overall system.FIGS. 12-14 show the power plant assembly 60 coupled to the EPS system housing 100 in another orientation with the external MSB 99. In the illustrated embodiment, the connection points 90, 94 are directed away from the housing 62. This illustrates what may be referred to as "mirrored" orientation relative to the embodiment shown in FIGS. 9-11. Arrows 98 represent the rotation of the prime mover assembly 60. In other words, the angular position of the prime mover assembly 60 may be changed to meet the most desirable system orientation required for the overall system.FIGS. 15-18 show the power plant assembly 60 coupled to an EPS system housing 100 according to a first orientation with an internal MSB. In the illustrated embodiment, the connection points 90, 94 are directed toward the housing 62. Arrows 98 represent the rotation of the prime mover assembly 60. In other words, the angular position of the power plant assembly 60 may be varied to meet the most desirable system orientation for the overall system.FIGS. 18-20 show the power plant assembly 60 coupled to the EPS system housing 100 according to another orientation with the internal MSB. In the illustrated embodiment, the connection points 90, 94 are directed away from the housing 62. This illustrates what may be referred to as "mirrored" orientation relative to the embodiment shown in FIGS. 15-18. Arrows 98 represent the rotation of the prime mover assembly 60. In other words, the angular position of the prime mover assembly 60 may be changed to meet the most desirable system orientation required for the overall system.Referring now to FIG. 21, the prime mover assembly 60 is illustrated with the first and second connection points 90, 94 separated by a circumferential spacing of the connection points 90, 94 on the extension segments. The degree of separation of the first and second connection points 90, 94 is adjustable. In the illustrated embodiment, the connection points (i.e., the headers) 90, 94 are separated by about 180 degrees, but it should be understood that this is only one example of the amount of separation that can be provided with these circuit board extension segments 80, 82 of the control board 68. For example, in example embodiments, the connection points 90, 94 may be separated by more than 45 degrees or more than 90 degrees.The power plant assembly also includes the power inductance disclosed herein for connection to a power source, such as a battery, while providing a compliant connection to the circuit board. In addition, one or more electrical connectors are provided for electrical connection to various other components.The embodiments disclosed herein maintain a common printed circuit layout within the motor housing diameter. This allows common motor connection points on the circuit board extension segments to be reconfigured to accept different customer requirements for the vehicle harness interface. Moreover, the battery power terminals are disconnected from the logic or communication circuits, thereby increasing the variation possibilities.The disclosed embodiments provide design flexibility to offer different connector access positions based on vehicle mounting space and customer preferences. The ability to maintain a common power plant layout while changing connector position is an improvement over previous power plant designs. The use of the circuit board with adjustable board configurations allows for a low cost connection to the controller.The placement of the main component structure within the substantially round diameter of the housing 62 provides the ability to equip and not equip circuits without compromising the primary engine interface, while still providing the flexibility to offer different port locations without compromising the main structure of the controller and the power plant.

Claims

A power plant assembly (60) comprising: a housing (62) extending axially about a longitudinal axis; a control board (68) having a circuit board main portion (72) covered by the housing (62), a first circuit board extension segment (82), and a second circuit board extension segment (80); at least one logic connector (90) disposed on the first circuit board extension segment (82); and a power connector (94) disposed on the second circuit board extension segment (82), characterized in that the first circuit board extension segment (82) extends radially away from the longitudinal axis and out of the housing (62) and is not covered by the housing (62), and in that the second circuit board extension segment (80) extends radially away from the longitudinal axis and out of the housing (62) and is not covered by the housing (62).The power plant assembly (60) of claim 1, characterized in that the power plant assembly (60) further comprises a heat sink shell (64) operatively coupled to the housing (62) to enclose the circuit board main portion (72).The power plant assembly (60) of claim 2, characterized in that the heat sink shell (64) comprises a shell main portion and a first shell extension segment, the shell main portion corresponding to the circuit board main portion (72), and the first shell extension segment corresponding to the first circuit board extension segment (82).The power plant assembly (60) of claim 1, characterized in that the housing (62) comprises a cylindrical body.Drive assembly arrangement (60) according to Claim 1, characterized in that the first printed circuit board extension segment (82) and the second printed circuit board extension segment (80) are arranged adjacent to one another in the circumferential direction.The drive assembly assembly (60) of claim 1, characterized in that the first circuit board extension segment (82) and the second circuit board extension segment (80) are spaced apart from each other in the circumferential direction.The drive assembly assembly (60) of claim 6, characterized in that the first circuit board extension segment (82) and the second circuit board extension segment (80) are spaced apart from each other by more than 90 degrees in the circumferential direction.An electric power steering (EPS) system (40) comprising: an EPS housing (100); and a power plant assembly (60) comprising: a housing (62) having a body portion (74) that extends axially from a plurality of flange portions (78) toward an end face (76) about a longitudinal axis, the housing (62) operatively coupled to the EPS housing (100) with at least one mechanical fastener extending through at least one of the flange portions (78); a control board (68) having a circuit board main portion (72), a first circuit board extension segment (82), and a second circuit board extension segment (80), the circuit board main portion (72) being covered by the housing (62); at least one logic connector (90) disposed on the first circuit board extension segment (82); and at least one power connector (94) disposed on the second circuit board extension segment (80), characterized in that the first circuit board extension segment (82) extends radially away from the longitudinal axis and out of the housing (62) and is not covered by the housing (62), and that the second circuit board extension segment (80) extends radially away from the longitudinal axis and out of the housing (62) and is not covered by the housing (62).The EPS system (40) of claim 8, characterized in that the power plant assembly (60) further comprises a heat sink shell (64) operatively connected to the housing (62) to enclose the circuit board main portion (72).The EPS system (40) of claim 9, characterized in that the heat sink shell (64) comprises a shell main portion, a first shell extension segment, and a second shell extension segment, wherein the shell main portion corresponds to the circuit board main portion, the first shell extension segment corresponds to the first circuit board extension segment (82), and the second shell extension segment corresponds to the second circuit board extension segment (80).The EPS system (40) according to claim 8, characterized in that the housing (62) includes a cylindrical body.The EPS system (40) according to claim 8, characterized in that the first circuit board extension segment (82) and the second circuit board extension segment (80) are arranged side by side in the circumferential direction.The EPS system (40) of claim 8, characterized in that the first circuit board extension segment (82) and the second circuit board extension segment (80) are circumferentially spaced apart from each other.The EPS system (40) of claim 8, characterized in that the first circuit board extension segment (82) and the second circuit board extension segment (80) are circumferentially spaced apart by more than 90 degrees.The EPS system (40) of claim 8, characterized in that the at least one logic connector (90) and the at least one power connector (94) each face the housing (62).The EPS system (40) of claim 8, characterized in that the at least one logic connector (90) and the at least one power connector (94) each face the EPS housing (100).

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