Abstract:
A motor driven compressor has a motor and a compressing mechanism connected to the motor through a rotary shaft, which is located within a housing, and an offset of phase is set between a stator and a rotor. The rotor is mounted to the rotary shaft, allowing the rotor to rotate so that it may be magnetized. Further, the motor driven compressor has a driving member driven together with the rotary shaft, a communication gas hole formed within the housing and extending from a suction port to a discharge hole, and a mark positioned along a radial axis on a first end surface of the driving member. The mark is used for setting the offset of phase between the stator and the rotor on the basis of a mark, by positioning the mark opposite the suction port. Accordingly, the motor driven compressor has a structure, which allows the rotor to be readily magnetized and may reliably set the offset of phase between the rotor and stator for magnetizing the rotor.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to motor driven compressors incorporated in air conditioning systems. 
     2. Description of Related Art 
     Known motor driven compressors include a compressing mechanism and a motor, which includes a rotary shaft, which are located within a housing. The rotary shaft drives the compressing mechanism within the housing. In such motor driven compressors, a stator and a rotor, comprising the motor, may be positioned within the housing. An offset of phase between the stator and the rotor is set, and the rotor then is magnetized. 
     FIG. # 8  depicts a partial cross-sectional view of a known motor driven compressor, as described in Japanese Patent Application Publication No. 09-45530. 
     Referring to FIG. # 8 , the motor driven compressor includes a;,direct current motor  102  and compressing mechanism (not shown), which is connected to direct current motor  102  via a rotary shaft  103  within a housing  101 . Direct current motor  102  includes stator  104  and rotor  105 . Stator  104  is fixed within housing  101 , and rotor  105  is mounted on rotary shaft  103 . Rotary shaft  103  is rotatably supported by bearing  120 . Suction port  109  is formed within housing  101 . A mark  108 , such as crossing groove, is formed on a first end surface of rotary shaft  103 . Housing  101  has a hole  106 , which is positioned opposite a second end of rotary shaft  103 . Hole  106  is closed by a sealing bolt  107 . 
     In such known motor driven compressors, after direct current motor  102 , rotary shaft  103 , and compressing mechanism (not shown) are positioned within housing  101 , the offset of phase between stator  104  and rotor  105  is set using a jig (not shown), such as a positioning member. Specifically, from outside housing  101 , the jig (not shown) engages with mark  108  through hole  106 . Subsequently, the jig is rotated around its axis to rotate rotary shaft  103  and rotor  105 . Thereby, the phase offset between stator  104  and rotor  105  is set. Once in position, rotor  102  is magnetized. Finally, after magnetization, hole  106  is closed by sealing bolt  107 . Magnetization occurs when current is provided to stator  104  via an electrical wire (not shown), which causes a magnetic force generated in stator  104  to act upon rotor  105 . 
     In the known motor driven compressor described above, after magnetization, hole  106  of housing  101  is closed by sealing bolt  107 . This configuration complicates such compressor&#39;s structure by increasing the number of parts. 
     FIG. # 9  depicts a partial cross-sectional view of another known motor driven compressor, as also described in Japanese Patent Application Publication No. 09-45530. 
     A mark  118  is formed on a first end surface of rotor  105  of direct current motor  102 . Suction port  109  is formed within housing  101 . Suction port  109  is positioned opposite mark  118 . In this known motor driven compressor, after direct current motor  102  and compressing mechanism are installed and enclosed within housing  101 , a jig (not shown) is inserted inside housing  101  through suction port  109 . Subsequently, rotor  105  is rotated to offset the phase between stator  105  and rotor  104 , so as to position mark  118  of rotor  105  opposite suction port  109 . Finally, once mark  118  is in position, rotor  105  is magnetized. 
     In the known motor driven compressor described above, rotor  105  is machined with a mark, such as a hole. Therefore, this compressor has increased manufacturing costs and during machining, it is difficult to maintain the angle between rotor  105  and rotary shaft  103 . 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a motor driven compressor of structure, which allows the rotor to be readily magnetized, and which may reliably set the offset of phase between the rotor and stator for magnetizing the rotor. 
     It is an another object of the present invention to decrease the number of parts and to provide a motor driven compressor, in which the rotor need not be machined with a mark. 
     According to an embodiment of the present invention, a motor driven compressor has a motor and a compressing mechanism connected to the motor through a rotary shaft, which are located within a housing, and an offset of phase is set between a stator and a rotor. The rotor is mounted on the rotary shaft, which allows the rotor to rotate, so that it may be magnetized. Further, according to this embodiment, the housing of the motor driven compressor has a communication gas hole, which extends from a suction port to a discharge hole. Additionally, according to this embodiment, the motor driven compressor has a driving member driven together with the rotary shaft, and a mark positioned along a radial axis on a first end surface of the driving member. The mark is used for setting the offset of phase between the stator and the rotor on the basis of the mark, by positioning the mark opposite the suction port. 
     According to another embodiment of the present invention, a rotor in a motor driven compressor is magnetized by connecting a compressing mechanism to the motor through a rotary shaft, which are located within a housing, and setting the offset of phase between a stator of the motor and the rotor, where the rotor is mounted to a rotary shaft, allowing the rotor to rotate, so that it may be magnetized. Additionally, according to this embodiment, a driving member is driven together with the rotary shaft, and a mark is positioned along a radial axis on a first end surface of the driving for setting the offset of phase between the stator and the rotor on the basis of the mark, by positioning the mark opposite the suction port. 
     Other objects, features, and advantages will be apparent to persons of ordinary skill in the art in view of the following detailed description of the invention and the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a cross-sectional view of the motor driven compressor in accordance with a first embodiment of a present invention. 
     FIG.  2 ( a ) is a plane view of the rotor of FIG. 1, FIG.  2 ( b ) is a vertical-sectional view of FIG.  2 ( a ). 
     FIG. 3 is a plane view of the rotor of the motor driven compressor in accordance with a second embodiment of a present invention. 
     FIG. 4 is a partial, cross-sectional view of the motor driven compressor in accordance with a third embodiment of a present invention. 
     FIG. 5 is a plane view of the counterbalance weight of FIG.  4 . 
     FIG. 6 is a plane view of the counterbalance weight of the motor driven compressor in accordance with a fourth embodiment of a present invention. 
     FIG. 7 is a cross-sectional view of the motor driven compressor in accordance with a fifth embodiment of a present invention. 
     FIG. 8 is a partial, cross-sectional view of a known motor driven compressor. 
     FIG. 9 is a partial, cross-sectional view of another known motor driven compressor. 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. # 1  shows a cross-sectional view of a motor driven compressor in accordance with a first embodiment of the present invention. 
     With reference to FIG. # 1 , motor driven compressor  10  includes scroll compressing mechanism  20 , rotary shaft  21 , and motor  60 . The scroll compressing mechanism  20 , rotary shaft  21 , and motor  60  are accommodated within casing  9 . Casing  9  is comprised of first housing portion  11 , second housing portion  12 , and third housing portion  13 . Housing portions  11 ,  12 , and  13  are connected to each other via bolts  53 . 
     Scroll compressing mechanism  20  is disposed within first housing portion  11 . Scroll compressing mechanism  20  includes fixed scroll member  30 , which is fixed within first housing portion  11 , and orbiting scroll member  40 , which is engaged with fixed scroll member  30 . Orbiting scroll member  40  includes bottom plate  42 ; spiral element  43 , which is formed on a first end surface of bottom plate  42 ; and boss member  41 , which is formed on a second end surface of bottom plate  42 . Orbiting scroll member  40  is supported on a first end of second housing portion  12  by a rotation preventing mechanism  45 . Rotation preventing mechanism  45  is comprised of a ball-coupling, which is disposed around boss member  41 . Fixed scroll member  30  includes bottom plate  31 ; spiral element  32 , which is formed on a first end surface of bottom plate  31 ; discharge valve mechanism  33 , which is formed on a second end surface of bottom plate  31 ; and fixed member  34 . Fixed scroll member  30  is fixed to bottom wall portion  11   a  of first housing portion  11  by bolts  54  via fixed member  34 . Moreover, discharge valve mechanism  33  may discharge fluid from motor driven compressor  10 . 
     Motor  60  is accommodated within space  25  of second housing portion  12  and third housing portion  13 . Motor  60  is comprised of stator  15  and rotor  16 . Stator  15  is fixed within housing portions  12  and  13 . Rotor  16  is mounted to rotary shaft  21 . 
     A first end of rotary shaft  21  is rotatably supported by bearing  18 , which is disposed within boss member  13   a  of third housing portion  13 . A second end of rotary shaft  21  includes large diameter portion  21   a.  Large diameter potion  21   a  is rotatably supported by bearing  19 , which is disposed within small diameter portion  12   a  of second housing portion  12 . A first end of large diameter potion  21   a  includes pin member  21   b , which projects from the end surface of large diameter potion  21   a . The axis of pin member  21   b  is radially offset from the axis of rotary shaft  21 . Pin member  21   b  is rotatably disposed within hole  22   a  of bushing  22 . The axis of hole  22   a  of bushing  22  is radially offset from the axis of bushing  22 . Bushing  22  is rotatably disposed within boss  41  of orbiting scroll member  40  through bearing  23 . 
     A first end of third housing portion  13  includes suction port  1  and connector  24  for connecting a coil of rotor  16  to an external power source. 
     A first end surface of rotor  16  includes counterbalance weight  2 , which reduces or eliminates the unbalancing effect on orbiting scroll member  40 . 
     In the above described motor driven compressor  10 , when motor  60  rotates rotary shaft  21 , orbiting scroll member  40  orbits fixed scroll member  30 , without rotating. Thus, refrigerant gas, which is introduced from a component, such as an evaporator (not shown) of a refrigerant circuit (not shown), through suction port  1 , travels through spaces  25  and  26  into the fluid pockets  27 , which are formed from the outer end portion of the spiral elements  32  and  43 . The refrigerant which traveled into the fluid pockets  27  then is compressed and discharged through discharge port  36 , discharge chamber  28  and discharge hole  51 , from which it then travels to another component, such as a condenser (not shown) of the refrigerant circuit (not shown). This passage, extending from the suction port  1  to the discharge hole  51 , through which the refrigerant gas travels, defines a communication gas chamber. 
     With reference to FIG. # 2 , counterbalance weight  2  is fixed on a first end surface of rotor  16  by fixed member  17 , such as by pins or bolts. Moreover, rotary shaft  21  is inserted through and fixed by hole  14 . Counterbalance weight  2  is half-ring shaped. Mark  3  is formed on a first end surface of counterbalance weight  2 , such as a hole. Mark  3  is located at a central position along a radial axis on counterbalance weight  2 . With reference to FIG. # 1 , mark  3  opposes suction port  1 . 
     To set the offset of phase between stator  15  and rotor  16  prior to magnetizing rotor  16 , from the outside of compressor  10 , a jig, such as positioning pin (not shown), is inserted inside housing portion  13  through suction port  1 . Subsequently, the offset of phase between stator  105  and rotor  104  is set on the basis of mark  3 , so as to oppose mark  3  to suction port  1  using the jig. Finally, once mark  3  is in position, current is provided to stator  16  via an electrical wire (not shown), which causes a magnetic force from stator  15  to act upon on rotor  16 . 
     FIG. # 3  shows a plane view of the rotor  16  of the motor driven compressor in accordance with a second embodiment of a present invention. The compressor has substantially the same structure as the motor driven compressor according to the first embodiment of the present invention. Therefore, the following description focuses on the differences between the first and second embodiments. 
     With reference to FIG. # 3 , a half-ring shaped counterbalance weight  2  includes a first side of rotor  16 . Counterbalance weight  2 ′ has substantially the same profile as counter balance weight  2  of the motor driven compressor, as described in FIG. # 2 , except it does not include mark  3 . Instead, counterbalance weight  2 ′ of FIG. # 3  uses the cross sectional portion  4  in place of mark  3  of FIG. # 2 , to position rotor  16 . Specifically, the offset of the phase between stator  15  and rotor  16  is set on the basis of cross-sectional portion  4  for magnetization of rotor  16  using a jig (not shown), such as positioning a pin through suction port  1 . 
     FIG. # 4  shows a partial, cross-sectional view of the motor driven compressor in accordance with a third embodiment of a present invention. FIG. # 5  is a plane view of the counterbalance weight  5  of FIG. # 4 . The compressor FIGS. # 4  and # 5  differs from the compressor according to the first and second embodiments of the present invention. The following discussion will focus on these differences. 
     With reference to FIG. # 4  and FIG. # 5 , counterbalance weight  5  is fixed to rotary shaft  21  by fixed member  5   b , such as by a screw. Counterbalance weight  5  is ring-shaped, and a lower area of counterbalance weight  5  is formed with an area greater than that of the upper area of counterbalance weight  5 . Counterbalance weight  5  has a screw hole  5   a  formed along a radial direction on counterbalance weight  5 . Further, rotary shaft  21  is formed in key groove  21   c.  Mark  6 , such as a hole, is formed on a first end surface of counterbalance weight  5 . Mark  6  is located at a central position along a radial axis on counterbalance weight  5 . With reference to FIG.4, mark  3  opposes suction port  1 . 
     The compressor has substantially the same structure as the motor driven compressor according to the first embodiment of the present invention, except that counterbalance weight  5  is fixed to rotary shaft  21  instead of a first end portion of rotor  16 . Therefore, the following discussion will focus only on these differences between the first and third embodiments. Specifically, the offset of phase between stator  15  and rotor  16  is set on the basis of mark  6  for magnetizing rotor  16  using a jig, such as positioning pin (not shown), through suction port  1 . 
     FIG. # 6  shows a plane view of the counterbalance weight  5 ′ of a motor driven compressor in accordance with a fourth embodiment of the present invention. 
     Counterbalance weight  5 ′ has substantially the same profile as counterbalance weight  5  of FIG. 5, except it does not include mark  6 . Instead, counterbalance weight  5 ′ of FIG. # 6  uses the cross-sectional portion  7  in place of mark  6  to position rotor  16 . In other words, the offset of phase between stator  15  and rotor  16  is set on the basis of cross-sectional portion  7  for magnetizing rotor  16 , using a jig (not shown), such as a positioning pin through suction port  1 . 
     The motor driven compressor described above according to the first, second, third, and fourth embodiments of the present invention, may set the offset of phase between stator  15  and rotor  16  by using counterbalance weights  2 ,  2 ′,  5 , and  5 ′ to maintain rotary balance. Consequently, in these embodiments, rotor  16  need not be machined with a mark, such as a hole, and the locating hole need not be closed, such as by using a sealing bolt. Thus, these embodiments may achieve a motor driven compressor of reduced cost. 
     FIG.7 shows a cross-sectional view of the motor driven compressor in accordance with fifth embodiment of the present invention. The compressor has substantially the same structure as the motor driven compressor according to the above described embodiments, except suction hole  52  of third housing portion  13  is located substantially on the axis of the rotary shaft  21 , and orbiting scroll member  40  has a mark  8 , such as concave groove. Mark  8  is formed on a central end portion of  42   a  of bottom plate  42  of orbiting scroll member  40 . Discharge hole  51  is located about on the axis of the discharge port  36 . Mark  8  is located at a position corresponding to discharge hole  51  and discharge port  36 . 
     The offset of phase between stator  15  and rotor  16  is set on the basis of mark  8  of orbiting scroll member  40  for magnetizing rotor  16 , using a jig, such as a positioning pin (not shown), through discharge hole  51  and discharge port  36 . 
     The motor driven compressor  50 , in accordance with the fifth embodiment of the present invention, may set the position of rotor  16  with stator  15  based on an orientation between discharge hole  51 , discharge port  36 , and mark  8  of orbiting scroll member  40 . Consequently, in this embodiment, rotor  16  need not be machined with a mark, such as a hole, and the locating hole need not be closed, such as by using a sealing bolt (FIG. # 8 ). Thus, this embodiment also may produce a motor driven compressor of reduced cost. 
     This invention has been described in connection with preferred embodiments. These embodiments, however, are merely exemplary, and the invention is not intended to be restricted thereto. It will be understood by those of skill in the art that variations may be readily made within the scope of this invention, as defined by the appended claims.