Stator terminal connector with baffle plate

Abstract

The invention provides a stator terminal connector with a baffle plate. A stator of an electric motor for a vehicle utilizes a molded terminal connector. The molded terminal connector also acts as a baffle to distribute cooling fluid around an end winding of the stator. The molded terminal connector includes a non-conductive cylindrical portion and a frame into which a conductive terminal is molded. The terminal includes a winding chain electrically connected to the end winding and a power chain electrically connected to an inverter.

Description

Technical Field

[0001] The present disclosure relates to electric motors for electrified vehicle powertrains. More particularly, the present disclosure relates to motors having terminal connectors with baffles to distribute coolant around end windings. Background Art

[0002] An electrified vehicle includes at least one electric motor that converts electrical power into mechanical power to propel the vehicle. In many cases, the electric motor is reversible, which means that it can also be used during braking to convert kinetic energy into electrical energy for storage in a battery. One type of electric motor commonly used in electrified powertrains is a permanent magnet synchronous motor. A permanent magnet synchronous motor includes a stator and a rotor. The stator includes windings. Most commonly, the windings are divided into three different phases, each of which is supplied with AC power that is 120 degrees out of phase. Due to the resistance in the windings, some of the power is converted into heat. Summary of the invention

[0003] A terminal connector for an electric motor, the terminal connector having a cylindrical baffle, a non-conductive frame and a plurality of conductive terminals. The non-conductive frame extends radially inward from a first end of the cylindrical baffle. The cylindrical baffle and the frame may be made of plastic. The conductive terminals are fixed to the frame. For example, three terminals may be molded into the frame. Each of the terminals has a winding chain extending toward a second end of the cylindrical baffle and a power chain extending radially outward from the cylindrical baffle. The terminals are electrically isolated from each other. A coolant inlet port may extend from the frame to direct liquid coolant into the interior of the cylindrical baffle. The cylindrical baffle may define one or more coolant outlet holes.

[0004] A stator for an electric motor includes a magnetic core, a conductive winding, and a terminal connector. The magnetic core has a plurality of magnetic poles. The conductive winding surrounds the magnetic poles and includes an end winding extending beyond the end of the core. The terminal connector has a cylindrical baffle surrounding the end winding and a frame extending radially inward from the cylindrical baffle adjacent to the winding. The cylindrical baffle and the frame may be made of plastic. A plurality of conductive terminals are fixed to the frame. For example, three terminals may be molded into the frame. Each of the terminals is electrically connected to the end winding and has an electric chain extending from the terminal connector. The electric chain may extend radially to the outside of the cylindrical baffle. A coolant inlet port may extend from the frame of the terminal connector and be used to guide liquid coolant to the end winding. The cylindrical baffle may define one or more coolant outlet holes.

[0005] A vehicle includes a stator, an inverter, and a terminal connector. The stator has a magnetic core and a conductive winding. The winding includes an end winding that extends beyond the end of the core. The inverter converts DC power from a battery into three-phase AC power. The terminal connector has a cylindrical baffle surrounding the end winding, a frame extending radially inward from the cylindrical baffle adjacent to the winding, and a plurality of conductive terminals molded into the frame. The cylindrical baffle and the frame may be made of plastic. Each of the terminals is electrically connected to the end winding and receives one of the three phases of AC power. The terminal may be connected to the AC power via an electric chain member that extends radially outside the cylindrical baffle. A coolant inlet port may extend from the frame of the terminal connector to guide liquid coolant to the end winding. The cylindrical baffle may define one or more coolant outlet holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] Figure 1 A block diagram of an electric vehicle is shown.

[0007] Figure 2 A schematic diagram of components of an electric drive system of an electric vehicle is shown, including a traction battery, a power electronics module with a DC-link capacitor and an inverter, and a motor.

[0008] Figure 3 and Figure 4 A stator having a molded terminal connector suitable for use in a Figure 2 Electric drive system Figure 1 used in electric vehicles. DETAILED DESCRIPTION

[0009] Detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention that may be embodied in various forms and alternative forms. The drawings are not necessarily drawn to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to utilize the present invention in various forms.

[0010] Reference now Figure 1, a block diagram of an exemplary electric vehicle ("EV") 12 is shown. In this example, the EV 12 is a plug-in hybrid electric vehicle (PHEV). The EV 12 includes one or more electric machines 14 ("e-machines") that are mechanically connected to a transmission 16. The electric machine 14 is capable of operating as a motor and a generator. The transmission 16 is mechanically connected to an engine 18 and a drive shaft 20 that is mechanically connected to wheels 22. The electric machine 14 can provide propulsion and retarding capabilities when the engine 18 is turned on or off. The electric machine 14, acting as a generator, can recover energy that might normally be lost as heat in a friction braking system. The electric machine 14 can reduce vehicle emissions by allowing the engine 18 to operate at a more efficient speed and allowing the EV 12 to operate in an electric mode with the engine 18 turned off under certain conditions.

[0011] The traction battery 24 ("battery") stores energy that can be used by the motor 14 to propel the EV 12. The battery 24 generally provides a high voltage (HV) direct current (DC) output. The battery 24 is electrically connected to a power electronics module 26. The power electronics module 26 is electrically connected to the motor 14 and provides the ability to transfer energy bidirectionally between the battery 24 and the motor. For example, the battery 24 may provide a direct current DC voltage, while the motor 14 may require a three-phase alternating current (AC) voltage to operate. The power electronics module 26 may convert the DC voltage to a three-phase AC voltage to operate the motor 14. In a regenerative mode, the power electronics module 26 may convert the three-phase AC voltage from the motor 14 acting as a generator to a DC voltage that is compatible with the battery 24.

[0012] The battery 24 can be recharged by an external power source 36 (e.g., an electrical grid). An electric vehicle supply equipment (EVSE) 38 is connected to the external power source 36. The EVSE 38 provides circuits and controls to control and manage the energy transfer between the external power source 36 and the EV 12. The external power source 36 can provide DC or AC power to the EVSE 38. The EVSE 38 can have a charging connector 40 for plugging into a charging port 34 of the EV 12. The charging port 34 can be any type of port configured to transfer power from the EVSE 38 to the EV 12. The power conversion module 32 of the EV 12 can regulate the power supplied from the EVSE 38 to provide the appropriate voltage and current levels to the battery 24. The power conversion module 32 can interface with the EVSE 38 to coordinate the power delivery to the battery 24. Alternatively, the various components described as being electrically connected can use wireless inductive coupling to transfer power.

[0013] Wheel brakes 44 are provided for slowing and stopping the movement of the EV 12. The wheel brakes 44 are part of a braking system 50. The braking system 50 may include a controller for monitoring and controlling the wheel brakes 44 to achieve desired operation.

[0014] The various components discussed may have one or more associated controllers to control and monitor the operation of the components. The controllers may be microprocessor-based devices. The controllers may communicate via a serial bus (e.g., a controller area network (CAN)) or via discrete conductors. For example, there is a system controller 48 (i.e., a vehicle controller) to coordinate the operation of the various components.

[0015] As depicted, the EV 12 in this example is a PHEV having an engine 18 and a battery 24. In other embodiments, the EV 12 is a battery electric vehicle (BEV). In a BEV configuration, the EV 12 does not include an engine.

[0016] Reference now Figure 2 , while continuing to refer to Figure 1 , a schematic diagram showing components of the electric drive system of the EV 12 is shown. Figure 2 As shown in , the electric drive system of the EV 12 includes a traction battery 24 , a power electronics module 26 , and an electric machine (ie, “motor”) 14 .

[0017] As described above, the power electronics module 26 is coupled between the battery 24 and the motor 14. The power electronics module 26 converts the DC power provided from the battery 24 into AC power to provide to the motor 14. In this way, the power electronics module 26 utilizes power from the battery 24 to drive the motor 14 to motor propel the EV 12.

[0018] The power electronics module 26 includes a DC link capacitor 62 and an inverter 60 (or “inverter control system” (“ICS”)). Figure 2 The inverter 60 shown in FIG. 6 is an exemplary inverter. A DC link capacitor 62 is provided between the battery 24 and the inverter 60 and is connected in parallel with the battery 24. The DC link capacitor 62 is operable to absorb ripple current generated by the operation of the power switch of the inverter 60 and stabilize the DC link voltage Vo used for the inverter 60 control.

[0019] As is known to those of ordinary skill, an inverter converts DC power into multi-phase AC power (three phase being the most common). An inverter can move power in either direction (bidirectional) to drive an electric machine (i.e., motor) or to electrically brake the electric machine (i.e., generate electricity). An inverter system consists of a combination of power electronics hardware (switches) and control software ( Figure 2 is a representative figure). The current can be adjusted quickly by opening and closing the power switch in the inverter.

[0020] Many inverter systems (including inverters associated with embodiments of the present disclosure, such as inverter 60) perform closed-loop current control to accurately control the motor. To accomplish this, current sensors are used to sense the current in each phase of the inverter, and corresponding signals are provided to a controller of the inverter system. The most common approach is to sense all phases, but any one phase current can be inferred from knowledge of the other phase currents. The current sensors may be implemented using different techniques and / or with different technologies, and the following discussion will provide an example of a current sensor. Figure 2 The current sensor 70 shown in FIG. 1 is only an example. Such current sensors are usually integrated into the inverter.

[0021] The inverter 60 includes an inverter circuit and a plurality of power switch units 64. As known to those skilled in the art, in the exemplary embodiment, the inverter 60 includes three groups of paired power switch units 64 (ie, Figure 2 As shown in , three×two=a total of six power switch units 64). Each pair of power switch units 64 includes two power switch units 64 connected in series. Each power switch unit 64 includes a power switch 66 in the form of a transistor, which is arranged in reverse parallel with a diode 68. In this example, the transistor is an insulated gate bipolar transistor (IGBT). Each pair of power switch units 64 is connected in parallel with the battery 24 and the DC link capacitor 62, and thus each pair of power switch units forms a "phase" of the inverter 60. In this way, the inverter 60 with three pairs of power switch units 64 is a three-phase inverter, which is operable to convert DC power from the battery 24 into three-phase AC power to be provided to the motor 14.

[0022] In addition, each phase of the inverter 60 includes a current sensor 70. For example, each current sensor 70 is a resistive shunt connected in series with the output of the corresponding phase. The current sensor 70 is operable to sense the current (I AC ).

[0023] In addition, a current sensor 71 is associated with the DC link capacitor 62. For example, the current sensor 71 is a resistor shunt connected in series with the DC link capacitor 62. The current sensor 71 is operable to sense the electrical ripple current (I 纹波 Alternatively, the electrical ripple current (I 纹波 ).

[0024] In addition, a current sensor 73 is associated with the input of the inverter 60. For example, the current sensor 73 is a resistive shunt connected in series with the input of the inverter 60 (i.e., extending from the node where the traction battery 24, the DC link capacitor 62, and the inverter 60 are connected toward the inverter 60). The current sensor 73 is operable to sense the electrical input DC current (I DC ).

[0025] The power electronics module 26 has an associated controller 63. The controller 63 may be a microprocessor-based device. The controller 63 is configured to monitor the operation of the DC link capacitor 62, and to monitor and control the operation of the inverter 60. In particular, the controller 63 is operable to control the operation of the power switch 66 so that the inverter 60 converts a given DC power provided by the battery 24 via the DC link capacitor 62 into a desired AC power to be provided to the motor 14. The controller 63 communicates with the current sensor 70 to monitor the AC power provided to the motor 14 from the inverter 60. The controller 63 uses the information of the current sensor 70 as feedback to control the inverter 60 to output the desired AC power to the motor 14.

[0026] Figure 3 and Figure 4 The stator of the motor 14 is shown. The stator includes a magnetic core 80. The core 80 is cylindrical and has a set of inwardly protruding magnetic poles 82. Three sets of conductive windings surround each of the magnetic poles, one set of conductive windings for each of the three phases of the motor. The windings include end windings 84 that extend beyond the ends of the core. A molded terminal connector 86 is assembled around the end windings and provides an electrical connection point to the inverter 60. The terminal connector includes a cylindrical portion 88 (not necessarily a cylinder) and a frame 90 that extends inward from the end of the cylindrical portion. The cylindrical portion and the frame can be integrally formed of a non-conductive material such as plastic via a process such as injection molding. Three conductive terminals 92 are fixed to the frame, such as by molding to the frame. Each of the terminals includes a winding chain 94 extending from the frame toward the end windings. Each winding chain is electrically connected to the end windings, such as by welding. Each of the terminals also includes a power chain 96 for connecting to the inverter. The terminal chain may extend radially outwardly from the cylindrical portion. A coolant inlet port 98 extends from the frame so that liquid coolant may be sprayed onto the end windings. The cylindrical portion includes a plurality of holes 100 for coolant to exit.

[0027] Figure 3 and Figure 4The molded terminal connector 86 uses a single part to perform the function of the terminal connector and also the function of the baffle. In addition to the financial savings associated with having fewer parts, this integrated design also provides several advantages over having separate parts for these functions. A separate baffle would need to have a larger average diameter than the cylindrical portion 88 to fit around the power chain member 96 during assembly. Therefore, it would not fit tightly with the end windings and would not effectively direct cooling fluid over the end windings. With the integrated design, the power chain member 96 can extend further outward, which simplifies making the required electrical connections after the stator is installed in the transmission housing. After the molded terminal connector is installed on the stator, it provides mechanical protection for the end windings, making it less likely to come into contact with the end windings during handling and assembly.

[0028] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms of the present invention. Rather, the words used in the specification are descriptive rather than restrictive words, and it should be understood that various changes may be made without departing from the spirit and scope of the present invention. In addition, the features of the various embodiments of implementation may be combined to form other embodiments of the present invention.

[0029] According to the present invention, a terminal connector for an electric motor is provided, the terminal connector comprising: a cylindrical baffle; a non-conductive frame extending radially inward from a first end of the cylindrical baffle; and a plurality of conductive terminals fixed to the frame, each of the terminals having a winding chain extending toward a second end of the cylindrical baffle and a power chain extending radially outward from the cylindrical baffle, the terminals being electrically isolated from each other.

[0030] According to one embodiment, the invention also features a coolant inlet port extending from the frame and configured to direct liquid coolant into the interior of the cylindrical baffle.

[0031] According to one embodiment, the cylindrical baffle defines one or more coolant outlet holes.

[0032] According to one embodiment, the cylindrical baffle and the frame are made of plastic.

[0033] According to one embodiment, the plurality of conductive terminals are molded into the frame.

[0034] According to one embodiment, the plurality of conductive terminals includes three terminals.

[0035] According to the present invention, there is provided a stator for an electric motor, the stator comprising: a magnetically conductive core having a plurality of magnetic poles; a conductive winding surrounding the magnetic poles, the conductive winding comprising an end winding extending beyond the end of the core; and a terminal connector comprising a cylindrical baffle surrounding the end winding, a frame extending radially inwardly from the cylindrical baffle adjacent to the winding, and a plurality of conductive terminals fixed to the frame, each of the terminals being electrically connected to the end winding and having an electric chain extending from the terminal connector.

[0036] According to one embodiment, the invention also features a coolant inlet port extending from the frame of the terminal connector and configured to direct liquid coolant onto the end windings.

[0037] According to one embodiment, the cylindrical baffle defines one or more coolant outlet holes.

[0038] According to one embodiment, the cylindrical baffle and the frame are made of plastic.

[0039] According to one embodiment, the plurality of conductive terminals are molded into the frame.

[0040] According to one embodiment, the plurality of conductive terminals includes three terminals.

[0041] According to one embodiment, the power chain extends radially outside the cylindrical baffle.

[0042] According to the present invention, a vehicle is provided, the vehicle having: a stator having a magnetically conductive core and conductive windings, the windings including end windings extending beyond the ends of the core; an inverter configured to convert DC power from a battery into three-phase AC power; and a terminal connector having a cylindrical baffle surrounding the end windings, a frame extending radially inward from the cylindrical baffle adjacent to the windings, and a plurality of conductive terminals molded into the frame, each of the terminals being electrically connected to the end windings and receiving one of the three phases of AC power.

[0043] According to one embodiment, the invention also features a coolant inlet port extending from the frame of the terminal connector and configured to direct liquid coolant onto the end windings.

[0044] According to one embodiment, the cylindrical baffle defines one or more coolant outlet holes.

[0045] According to one embodiment, the cylindrical baffle and the frame are made of plastic.

[0046] According to one embodiment, the terminals are connected to the AC power via an electric power chain extending radially outside the cylindrical baffle.

Claims

1. A terminal connector for an electric motor, the terminal connector comprising: Cylindrical baffle; a non-conductive frame extending radially inwardly from a first end of the cylindrical baffle; as well as A plurality of conductive terminals are fixed to the frame, each of the terminals having a winding chain extending toward the second end of the cylindrical baffle and a power chain extending radially outward from the cylindrical baffle, the terminals being electrically isolated from each other. 2 . The terminal connector of claim 1 , further comprising a coolant inlet port extending from the frame and configured to direct liquid coolant into an interior of the cylindrical baffle.

3. The terminal connector of claim 2, wherein the cylindrical baffle defines one or more coolant outlet holes.

4. The terminal connector of claim 1, wherein the plurality of conductive terminals are molded into the frame.

5. A stator for an electric motor, the stator comprising: A magnetically conductive core, wherein the magnetically conductive core has a plurality of magnetic poles; an electrically conductive winding surrounding the pole, the winding including an end winding extending beyond an end of the core; as well as A terminal connector having a cylindrical baffle surrounding the end winding, a frame extending radially inward from the cylindrical baffle adjacent to the winding, and a plurality of conductive terminals fixed to the frame, each of the terminals being electrically connected to the end winding and having an electric chain extending from the terminal connector. 6 . The stator of claim 5 , further comprising a coolant inlet port extending from the frame of the terminal connector and configured to direct liquid coolant onto the end windings.

7. The stator of claim 6, wherein the cylindrical baffle defines one or more coolant exit holes.

8. The stator of claim 5, wherein the cylindrical baffle and the frame are made of plastic.

9. The stator of claim 8, wherein the plurality of conductive terminals are molded into the frame.

10. The stator of claim 5, wherein the power chain extends radially outside the cylindrical baffle.

11. A vehicle comprising: a stator having a magnetically conductive core and electrically conductive windings, the windings including end windings extending beyond ends of the core; an inverter configured to convert DC power from the battery into three-phase AC power; as well as A terminal connector having a cylindrical baffle surrounding the end winding, a frame extending radially inward from the cylindrical baffle adjacent the winding, and a plurality of conductive terminals molded into the frame, each of the terminals being electrically connected to the end winding and receiving one of the three phases of AC power.

12. The vehicle of claim 11 further comprising a coolant inlet port extending from the frame of the terminal connector and configured to direct liquid coolant onto the end windings.

13. The vehicle of claim 12, wherein the cylindrical baffle defines one or more coolant outlet apertures.

14. The vehicle of claim 11 wherein said cylindrical fender and said frame are made of plastic.

15. The vehicle of claim 11, wherein the terminals are connected to the AC power via a power link extending radially outside the cylindrical baffle.

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