Abstract:
A power collection device for an electric machine is provided, which includes: a carrier having a first surface, and a connecting member protruding outward from the first surface of the carrier and having at least a first groove. The first groove facilitates to reduce stresses experienced by the connecting member and allows applied stresses to change the configuration of the connection portion so as to increase the contact area between the connecting member and an object held in the connecting member. As such, the object is firmly secured in the connecting member and the processing convenience is increased.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application also claims priority to Taiwan Patent Application No. 103141749 filed in the Taiwan Patent Office on Dec. 2, 2014, the entire content of which is incorporated herein by reference. 
       BACKGROUND 
       [0002]    1. Technical Field 
         [0003]    The present disclosure relates to power collection devices for electric machines, and more particularly, to a power collection device for improving the fixing effect. 
         [0004]    2. Description of Related Art 
         [0005]      FIG. 1A  is a schematic view of a conventional mild hybrid propulsion system. Referring to  FIG. 1A , an integrated starter-generator (ISG)  7  is disposed between an engine  4  and a transmission  5 . To apply the mild hybrid propulsion system in a vehicle, the ISG is designed to have a minimized size so as to save space in the vehicle. 
         [0006]      FIG. 1B  is a schematic partial view of the ISG  7 . Referring to  FIGS. 1A and 1B , the ISG  7  has a stator  2  and a power collection device  9  disposed around the stator  2 . Copper wires  201  of the stator  2  are collected by the power collection device  9  into phase cables  3  for electrically connecting with an external electronic element. 
         [0007]    In particular, the stator  2  has a plurality of winding units  20 , and the power collection device  9  has a plurality of rivets  91 . The copper wires  201  of the winding units  20  are wound to the rivets  91  and bonded and fixed through a soldering process. Then, the copper wires  20  are collected by a guiding mechanism  92  into phase cables  3  for electrically connecting with an external electronic element. 
         [0008]    However, the rivet bonding method complicates the fabrication process and increases the volume of the ISG. Further, the rivets easily come loose. As such, the fabrication cost is increased and the product reliability is reduced. 
         [0009]    Therefore, how to overcome the above-described drawbacks has become critical. 
       SUMMARY 
       [0010]    In view of the above-described drawbacks, the present disclosure provides a power collection device for an electric machine, which comprises: a carrier of a ring shape having a first surface and a second surface; and at least a connecting member protruding outward from the first surface of the carrier, and having at least a first groove and a plane formed on two opposite sides of the connecting member, respectively. 
         [0011]    The first groove facilitates to reduce stresses experienced by the connecting member and allows applied stresses to change the configuration of the connection portion wrapping copper wires so as to increase the contact area between the connecting member and the copper wires. As such, the copper wires are firmly secured in the connecting member and the processing convenience is increased. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0012]      FIG. 1A  is a schematic view of a conventional mild hybrid propulsion system; 
           [0013]      FIG. 1B  is a schematic partial view of a conventional ISG (integrated starter-generator); 
           [0014]      FIG. 2A  is a schematic partial view of a power collection device for an electric machine according to a first embodiment of the present disclosure; 
           [0015]      FIG. 2B  is a schematic partial view of a power collection device for an electric machine according to a second embodiment of the present disclosure; 
           [0016]      FIGS. 2C and 2D  are schematic views of a connecting member of the present disclosure; 
           [0017]      FIG. 3  is a schematic view showing folding of the connecting member of the present disclosure; 
           [0018]      FIG. 4  is a schematic partial view of an ISG of the present disclosure; 
           [0019]      FIGS. 5A and 5B  are schematic views showing folding of the connecting member of the present disclosure; and 
           [0020]      FIG. 6  is a schematic view of a mild hybrid propulsion system of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0021]    The following illustrative embodiments are provided to illustrate the present disclosure, these and other advantages and effects can be apparent to those in the art after reading this specification. It should be noted that all the drawings are not intended to limit the present disclosure. Various modifications and variations can be made without departing from the spirit of the present disclosure. 
         [0022]      FIG. 2A  is a schematic partial view of a power collection device  1  for an electric machine according to a first embodiment of the present disclosure, and  FIG. 2B  is a schematic partial view of the power collection device  1  for an electric machine according to a second embodiment of the present disclosure. 
         [0023]    The power collection device  1  has a carrier  10  and a connecting member  11 . The carrier  10  is of a ring shape, which has an outer diameter  101 , an inner diameter  102 , a first surface  103  and a second surface  104  (as shown in  FIG. 3 ). The connecting member  11  protrudes outward from the first surface  103 . The connecting member  11  is in a plate shape. At least two first grooves  111  are formed along a length extending direction of the connecting member  11 . Based on an inscribed circle principle, at least three second grooves  112  are formed along a width extending direction of the connecting member  11 . In the first embodiment, the first grooves  111  and the second grooves  112  face the outer diameter  101  of the carrier  10  according to the practical need. In the second embodiment, the first grooves  111  and the second grooves  112  face the inner diameter  102  of the carrier  10  according to the practical need. In both the first and second embodiments, one side of the connecting member  11  having the first grooves  111  and the second grooves  112  or the opposite side of the connecting member  11  having a contact plane  113  can be press-folded to wrap copper wires  201  (as shown in  FIGS. 5A and 5B ). When the connecting member  11  is press-folded to wrap the copper wires  201 , the first grooves  111  and the second grooves  112  are made to be in close contact with the copper wires  201 . Then, a pressure is applied to strengthen the bonding between the connecting member  11  and the copper wires  201 . For example, a metal material such as tin is filled between the connecting member  11  and the copper wires  201  to increase the contact area between the connecting member  11  and the copper wires  201 . As such, the bonding between the connecting member  11  and the copper wires  201  is strengthened and the copper wires  201  are firmly secured. Also, the conductivity is increased. Alternatively, when the connecting member  11  is press-folded to wrap the copper wires  201 , the contact plane  113  of the connecting member  11  is made to be in close contact with the copper wires  201  and a pressure is then applied to increase the contact area and the conductivity. For example, a metal material such as tin is filled between the connecting member  11  and the copper wires  201 . As such, the bonding between the connecting member  11  and the copper wires  201  is strengthened and the copper wires  201  are firmly secured. Also, the conductivity is increased. 
         [0024]    It should be noted that the carrier  10  and the connecting member  11  are integrally formed through a mechanical process such as stamping or molding, thus increasing the processing convenience and product reliability and reducing the fabrication cost. 
         [0025]    Referring to  FIGS. 2C and 2D , the second grooves  112  intersect with the first grooves  111 . The connecting member  11  has a first thickness T 1 , and the first grooves  111  or the second grooves  112  have a second thickness T 2 . The second thickness T 2  is not greater than two thirds of the first thickness T 1 . Otherwise, too deep grooves  111 ,  112  may reduce the strength of the connecting member  11 . Therefore, the relationship between the first thickness T 1  and the second thickness T 2  facilitates to reduce required processing stresses applied for folding the connecting member  11  to wrap the copper wires  201 , thereby increasing the processing convenience of the connecting member  11 . The first grooves  111  or the second grooves  112  can be with a U shape, a semi-circular shape or a V shape in cross-section thereof. In other embodiments, the first grooves  111  or the second grooves  112  may have such as a polygonal shape in cross section. 
         [0026]      FIG. 3  is a schematic view showing folding of the connecting member  11 . Therein, the connecting member  11  of the first embodiment is exemplified. 
         [0027]    According to the inscribed circle principle, the number of the first grooves  111  and the second grooves  112  are defined and formed. Accordingly, the connecting member  11  is press-folded into a triangular shape, a quadrangular shape and a polygonal shape. In the present disclosure, four second grooves  112  are formed. As such, after being press-folded, the connecting member  11  assumes a ring shape and has a receiving space S for firmly securing the copper wires  201  (as shown in  FIGS. 5A and 5B ). 
         [0028]    It should be noted that  FIG. 3  shows the shape of the connecting member  11  after being press-folded to wrap and firmly secure the copper wires  201  through the first grooves  111  and the second grooves  112 , and  FIGS. 5A and 5B  show the shape of the connecting member  11  after being press-folded and bend inward to wrap and firmly secure the copper wires  201  through the contact plane  113 . 
         [0029]      FIG. 4  is a schematic partial view of an ISG of the present disclosure. Referring to  FIG. 4 , a stator  2 , a power collection device  1  disposed around an outer periphery of the stator  2  and a housing  6  for receiving the stator  2  and the power collection device  1  are shown. 
         [0030]    The stator  2  has a plurality of winding units  20 . The copper wires of the winding units  20  are connected to the connecting member  11  of the power collection device  1  so as to be collected into phase cables  3 . The phase cables  3  are further connected to a fixing mechanism  60  of the housing  6 . The fixing mechanism  60  has waterproof and dustproof functions. The fixing mechanism  60  fixes the phase cables  3  and strengthens sealing of the housing  6 . According to the number of electrical phases of the ISG more than one phase cable  3  is provided. In the embodiment of  FIG. 4 , three phase cables are provided. 
         [0031]    Referring to  FIGS. 5A and 5B , the copper wires  201  of the winding units  20  are collected in the receiving space S of the connecting member  11 . The connecting member  11  is easily press-folded through the first grooves  111  and the second grooves  112 , and an external force is applied on an upper portion of the connecting member  11  to cause an upper middle portion of the receiving space S to bend inward (as shown in  FIG. 5B ). As such, the contact area between the connecting member  11  and the copper wires  201  is increased and hence the copper wires  201  are firmly secured in the connecting member  11  and the conductivity is increased. 
         [0032]      FIG. 6  is a schematic view of a mild hybrid propulsion system  900  of the present disclosure. Referring to  FIG. 6 , an ISG  7  of the present disclosure is sandwiched between an engine  4  and a transmission  5 . Copper wires are collected by the connecting member  11  of the power collection device  1  (shown in  FIG. 4 ) of the ISG  7  into phase cables  3  and directly received in the housing  6  (shown in  FIG. 4 ). As such, the phase cables  3  can be directly pulled out and electrically connected to an external electronic element. Therefore, the present disclosure dispenses with the conventional guiding mechanism, reduces the volume of the ISG  7 , and meets the miniaturization requirement of the mild hybrid propulsion system  900 . 
         [0033]    According to the present disclosure, the carrier and the connecting member are integrally formed through a mechanical process such as stamping or molding, thus increasing the processing convenience and product reliability and reducing the fabrication cost. 
         [0034]    Further, the first grooves and the second grooves of the connecting member facilitate to reduce processing stresses applied for folding the connecting member to wrap the copper wires, thereby increasing the processing convenience of the connecting member. 
         [0035]    Furthermore, since the copper wires are directly collected by the connecting member into phase cables that are directly received in the housing, the present disclosure dispenses with the conventional guiding mechanism that is disposed outside the housing for collecting the copper wires into phase cables, thereby reducing the volume of the ISG and meeting the miniaturization requirement of the mild hybrid propulsion system. Also, the present disclosure reduces locking mechanisms for terminals. 
         [0036]    In the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a through understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.