Abstract:
An apparatus electrically connects a motor&#39;s on-board stator circuit board to multiple circuits on a controller circuit board using an edge connector on the controller circuit board that engages opposing pads on an edge of the stator circuit board. The edge connector includes tuning-fork-like conductors each with pairs of protruding arms positioned to both engage the pads for electrical contact and also frictionally engage the pads for mechanical retention. A related method of assembly uses the edge-connect system for quick, reliable and sure assembly even under blind assembly conditions.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims benefit under 35 USC section 119(e) to U.S. Provisional Application No. 62/218,632, filed on Sep. 15, 2015, entitled VEHICLE-MOUNTED SENSORLESS MOTOR WITH EDGE-CONNECTED TERMINATION, the entire disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND 
     The present invention relates to a vehicle-mounted sensorless motor apparatus with a motor termination connector for motor phases U, V, and W; and more particularly relates to a motor having a stator circuit board integral to the motor, a controller circuit board separate from the stator circuit board, and mating connectors for connecting circuits between the circuit boards for controlling the motor phases U, V, and W. The present innovation is well adapted for use in an automatic transmission fluid pump/motor apparatus, but is not believed to be limited to only that use. 
     Sensorless automatic transmission fluid (ATF) motors can be used to drive pumps for pumping automatic transmission fluid on a vehicle. Such motors are useful for several reasons, including their compact design, reliability, control, and cost effectiveness. Sensorless ATF motors typically have a connector-based termination on the circuit boards for phases U, V, and W, so that a controller circuit board can control circuits defined in part by the stator circuit board for operating the motor&#39;s rotor. It is important that the assembly be compact, but also easily connected (since the assembly may be a blind assembly), reliably connected (including good and consistent electrical contact and that is also mechanically resistant to pull-apart), and assembled with a minimum of components and lower cost component (for competitive reasons). 
     One example of prior art is shown in  FIGS. 18-21 , which illustrates an ATF motor  100  connected to a pump positioned inside a transmission fluid pan for pumping pooled automotive transmission fluid as needed to vehicle components. The motor  100  includes a stator circuit board  101  with a first multi-point (female) connector  102  (sometimes called “terminal header”) soldered to the board  101 , and a controller circuit board  103  having a mating second multi-point (male) connector  104  (sometimes called a “socket header”) soldered to the board  103 , with the mating connectors  102  and  104  having mating pin and sockets for connecting different circuits between the circuit boards  101  and  103  for controlling phases U, V, and W of the motor  100  to rotate the motor&#39;s rotor. The connector  102  is soldered into the electronics in the stator circuit board  101 , and the connector  104  is soldered to the electronics of the controller circuit board  103 , which adds significant expense and is a quality concern. The male connector  104  includes multiple miniaturized parallel pins  105  adapted to fit snugly into mating sockets for electrical connection. The pins are designed to be as small as possible to meet space/size, weight, and functional requirements, since the space within the transmission fluid pan is small, but concurrently must be sufficiently large for good surface area for providing electrical connection. The connectors  102  and  104  both include metal conductors held by non-conductive material (such as plastic), with the non-conductive material being designed to assist with accurate alignment of the pins and sockets during assembly and interconnection, but also providing good retention strength after assembly. A quality problem occurs when one or more of the pins are deformed or damaged during assembly, resulting in poor (or no) electrical connection. This problem is compounded by the blind assembly, and by the small size and low bending strength of the pins. Improvement is desired to simplify the assembly, lower cost, improve assemble-ability (especially during a blind assembly), improve reliability of retention after assembly, improve integrity and reliability of the electrical connection made in the multiple circuits during assembly, doing so while maintaining low cost of components and assembly, and while also providing a design that takes up as small of space as possible by the components/assembly. 
     SUMMARY OF THE PRESENT INVENTION 
     In one aspect of the present invention, an apparatus for electrically connecting a motor&#39;s on-board stator circuit board to a controller circuit board, comprises: A) one of the stator circuit board and the controller circuit board including an edge with spaced-apart pads of electrically-conductive material for connecting to the multiple electrical circuits; and B) the other the stator circuit board and the controller circuit board including an edge connector with conductors each having at least one protruding arm positioned to both engage the pads for electrical contact and also frictionally engage the pads for mechanical retention. 
     In narrower aspects, the pads include first pads on one side and second pads on an opposite side that are aligned with the first pads; and the at least one protruding arm on each of the conductors includes opposing arms that define a pinch point therebetween, the pinch point being dimensioned to cause the opposing arms to each contact an associated one of the pads. 
     In another narrower aspect, the apparatus does not include any mechanical connecting structure creating a substantial retention force other than the retention force created by the conductors on the pads. 
     In another narrower aspect, the pads include duplicative pads on opposite sides of the circuit board, both connected to the electrical circuit, thus leading to a duplicative connection that is more reliable and robust. 
     In another aspect of the present invention, a method for electrically connecting a motor&#39;s on-board stator circuit board to a controller circuit board, comprises: A) providing on one of the stator circuit board and the controller circuit board, an edge with spaced-apart pads of electrically-conductive material for connecting to the multiple electrical circuits; B) providing on the other the stator circuit board and the controller circuit board, an edge connector with conductors each having at least one protruding arm positioned to both engage the pads; and C) assembling the edge connector onto the edge so that the conductors electrically engage the pads for electrical contact and also frictionally engage the pads for mechanical retention. 
     These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIGS. 1-1A  are side views, partially schematic, showing an ATF motor/pump apparatus submersed in automatic transmission fluid inside a transmission fluid pan, the motor including a stator circuit board connected to a controller circuit board, the controller circuit board including an edge-of-board electrical connector (called “edge connector”) with tuning-fork-like conductors for engaging mating conductive pads along an edge of the stator circuit board,  FIGS. 1 and 1A  showing the motor extending in different orientations (i.e. opposite directions). 
         FIG. 2  is a side view of the controller circuit board and circuit-board-attached edge connector of  FIG. 1 . 
         FIG. 3  is a perspective view of the edge connector engaging the pads on the (circle-shaped) stator circuit board. 
         FIG. 4  is a cross-sectional view showing the electrical connection provided by the tuning-fork-like conductors to the pads on the stator circuit board. 
         FIG. 5  is an exploded view of  FIG. 3  (with only the center one conductor  31  shown). 
         FIGS. 6-8  are views of one of the tuning-fork-like conductors,  FIGS. 6-7  being side and plan views,  FIG. 8  being an enlarged view of the circuit-board-attached pin on the conductor. 
         FIGS. 9-13  are views of the edge connector of  FIG. 3 ,  FIG. 9  being a perspective view, 
         FIGS. 10-12  being orthogonal views, and  FIG. 13  being a cross section showing the conductor inside the non-conductive plastic material of the edge connector. 
         FIG. 14  is a plan view of the stator circuit board of  FIGS. 1 and 2 . 
         FIGS. 15-16  are enlarged views of opposing sides of the end of the controller circuit board where the edge connector engages the controller circuit board. 
         FIG. 17  is a schematic showing a vehicle electrical system including a controller PCB connected using tuning-fork-connectors to conductive pads on a 1st on-board static motor PCB, and including a 2 nd  on-board static motor PCB connected using tuning-fork-connectors to conductive pads on the 1 st  on-board static motor PCB. 
         FIGS. 17A-17D  are layers of the stator circuit board, the layers showing redundant pads connected to circuits on the stator circuit board, the redundant pads causing redundant connection of the controller and stator circuit boards to improve sureness and robustness of the electrical connection. 
         FIGS. 18-19  are side views of prior art,  FIG. 18  showing a stator circuit board assembled to a controller circuit board by a male terminal header connector (with circumferential shield around projecting pins) and socket header connector,  FIG. 19  being an exploded view of same. 
         FIGS. 20 and 21  are perspective views of the socket header connector and terminal header connector shown in  FIGS. 18-19 . 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The present apparatus  20  ( FIG. 1 ) is illustrated as positioned in a transmission fluid pan  21  partially filled with transmission fluid, and includes a motor  21  with rotor  22  driving a pump  23  for pumping the automatic transmission fluid to various vehicle components. The motor  21  has a stator circuit board  25  integral to the motor and operably connected to its stator  26 , a controller circuit board  27  separate from the stator circuit board  25 , and a connector  28  on the controller circuit board  27  for electrically (and mechanically) connecting to a connecting arrangement of pads  30  on the stator circuit board  25  to connect to different circuits between the circuit boards  25  and  27  to control operation of the motor&#39;s rotor via phases U, V and W. The pads  30  on the stator circuit board  25  comprise enlarged spots of conductive material on opposing sides of the stator circuit board  25  near an edge of the circuit board  25 . For convenience, the pads  30  are referred to herein as a “connector arrangement”, since the pads  30  are arranged to provide connection and also provide frictional retention force by engaging the arms of the tuning-fork-like conductors  31  in the connector  28 . In a broadest sense, in the illustrated apparatus, it should be understood that there is no traditional connector on the controlling circuit board  27 . 
     The connector  28  is shown in  FIGS. 1 and 4 , which shows the assembly, and is shown in  FIGS. 6-8  which shows the conductors  31 , and in  FIGS. 10-13  which show the connector  28  with conductors  31 . The connector  28  includes a molded non-conductive body (of plastic) holding multiple tuning-fork-like conductors  31  (three shown) in parallel positions each defining an entrance “jaw” corresponding to the pads  30 . This arrangement allows for elimination of the socket header used in the prior art connector  101  described above and shown in  FIGS. 18-21 , which is a tremendous cost savings in material, assembly cost, and savings in space consumption. The conductors  31  have conductive arms  31 A that extend in a parallel direction, with the angled inner surfaces of the arms forming a funnel-shaped entrance  31 B (which facilitates blind assembly onto the edge of the stator circuit board  25 ), inwardly protruding bumps  31 C (which create a pinch point promoting good electrical connection to the pads  30  and also positive frictional retention forces on the pads  30  on opposing sides of the stator circuit board  25 ), and a spaced inner portion  31 D (for receiving the edge of the stator circuit board  25 . It is noted that the quality and surety of the electrical connection is greatly increased due to the electrical contact with pads  30  on opposite sides of the stator circuit board  25 . 
       FIG. 1  shows a particular arrangement where the motor&#39;s stator and rotor are shown extending away from the controller circuit board. However, this is done for convenience and illustrative clarity, but it is contemplated that the motor&#39;s stator and rotor can extend in any direction relative to each other. 
     Skilled artisans will understand that a variety of different materials and constructions are possible while staying within a scope of the present innovative concepts. The illustrated stator board  25  is a laminate type, the conductors  31  are a conductive metal having a Young&#39;s modulus of 131 GPa, and the terminal housing (plastic body of the connector  29 ) is a material having a Young&#39;s modulus of 10 GPa. The install force for assembly and retention forces for the assembly can be varied in a number of ways, such as for example by changing materials, treating the contacting surfaces with surface treatment (e.g. plating or coatings), and/or changing a shape of the conductor arms  31 A (i.e. changing the angle of the funnel entrance and/or of a dimension and shape of the pinch point and/or flexibility/resiliency of the arms). The illustrated prototype successfully passed several tests, including tests of lower install/higher retention forces, electrical integrity/ampacity, thermal shock, powered vibration with heat, and powered thermal cycle. It is noted that the present illustrated connection has operated effectively while communicating 20 amps or more. 
     The present arrangement is particularly useful in sensorless ATF (automatic transmission fluid) motors used to drive pumps for pumping automatic transmission fluid, because it provides a very compact design (needed for the small space requirements in a vehicle transmission pan), while maintaining or improving reliability and cost effectiveness (needed for the high quality standards required in modern vehicles). The present assembly provides for robust, positive, and relatively easy connection (even in a blind assembly), provides excellent reliability upon connection (including excellent duplicative electrical contact and also mechanical resistance to pull-apart), while using a minimum of number of components (due in part to eliminating one of the connectors used in traditional mating-pin-and-socket electrical connectors) and while also using low cost components and low cost assembly techniques/processes. It is contemplated that the above innovative aspects can include a device connected to and driven by the motor(s), such as any fluid pump or air pump device, a power steering device, an AC compressor, a motor-powered power brake, and substantially any motor-powered component or accessory used in a vehicle or in a larger assembly. 
       FIG. 17  is a schematic showing an alternative circuit comprising a vehicle electrical system including a controller PCB  27  connected using tuning-fork-connectors  28  with arm-like conductors  31  engaging conductive pads  30  on a 1st on-board static motor PCB  25 , and including a 2 nd  on-board static motor PCB  25 ′ connected using tuning-fork-connectors  28 ′ with conductors  31 ′ engaging conductive pads  30 ′ on an edge  25 ′ of the 1 st  on-board static motor PCB  25 . It is contemplated that variations are within a scope of the present invention. For example, both on-board static motor PCB&#39;s could be connected directly to the controller PCB, with both tuning-fork-connectors being on the controller PCB and with the conductive pads along the1 st  and 2 nd  on-board static motor PCBs. Also, the tuning-fork-connectors could be on the static motor PCB&#39;s, and the conductive pads along the edge of the controller PCB. It is contemplated that additional tuning-fork-connectors could be used to connect PCB&#39;s while minimizing or eliminating pre-assembled/pre-manufactured electrical connector components. 
       FIGS. 17A-17D  show adjacent layers of the stator circuit board  25 , where the layers include redundant pads (identified as items C, U, V, W) connected to circuits on the stator circuit board, the redundant pads causing redundant connection of the controller and stator circuit boards to improve sureness and robustness of the electrical connection. 
     It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.