Abstract:
A regulator assembly, comprising a vaned diffuser, a motor, a driving gear engaged with a driven gear, the driven gear having rectangle-shaped through holes thereon, the rectangle-shaped through holes disposed and extending along an axis of the driven gear, and a regulating mechanism including a regulator, a supporting member, wherein the regulator is sleeved on the supporting member, and wherein the vaned diffuser is fixed on the supporting member, and regulator sliding members fixed to the regulator through the rectangle-shaped through holes of the driven gear, whereby the motor is configured to drive the driving gear to rotate, the driving gear is configured to drive the driven gear to rotate, the driven gear is configured to push the regulator sliding members to move, and the regulator sliding members are configured to drive the regulator to rotate relative to the vaned diffuser, thus driving the regulator to move along its axis.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a U.S. National Phase application submitted under 35 U.S.C. §371 of Patent Cooperation Treaty application serial no. PCT/CN2014/084409, filed Aug. 14, 2014, and entitled REGULATOR STRUCTURE AND CENTRIFUGAL COMPRESSOR, which application claims priority to Chinese patent application serial no. 201310377440.4, filed Aug. 26, 2013, and entitled                      
         [0002]    Patent Cooperation Treaty application serial no. PCT/CN2014/084409, published as WO2015/027824, and CN patent application serial no. 201310377440.4, are incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0003]    The present disclosure relates to a regulator assembly, more particularly, to a regulator assembly for regulating the outlet width of the impeller of a centrifugal compressor, and to a centrifugal compressor. 
       BACKGROUND 
       [0004]    In a centrifugal compressor of the prior art, the regulator is installed at the outlet of the impeller, forming a segment with an adjustable width. The outlet width of the impeller is regulated according to the operating conditions of the unit, so as to enable the unit to remain at the highest operating efficiency in a wider range. In the prior art, the regulator of the centrifugal compressor is normally linked with the regulating mechanism of the impeller. The regulator is not independent in structure, and thus the control is not precise enough. What is more, the regulating range of the adjustable width of the impeller is relatively smaller, and the regulator of the centrifugal compressor is not applicable to compressors under various kinds of operating conditions. 
         [0005]    In view of the defects above, after long time of research and practice, the inventors finally obtained the present invention. 
       SUMMARY 
       [0006]    In view of the situations, it is imperative to provide a regulator assembly capable of realizing a larger regulating range, and to provide a centrifugal compressor. 
         [0007]    The present disclosure provides a regulator assembly, comprising a vaned diffuser, wherein, said regulator assembly further comprises a motor, a driving gear, a driven gear and a regulating mechanism;
       the motor is rotatable forwardly and reversibly; the driving gear is engaged with the driven gear;   the regulating mechanism comprises a regulator, a supporting member and regulator sliding members;   the driven gear is sleeved on the regulator; the regulator is sleeved on the supporting member;   the driven gear has rectangle-shaped through holes thereon, the rectangle-shaped through holes are disposed and extend along an axis of the driven gear;   the regulator sliding members are fixed to the regulator through the rectangle-shaped through holes;   the vaned diffuser is fixed on the supporting member, and is provided with internal threads;   the regulator is provided with external threads, the external threads are engageable with the internal threads of the vaned diffuser;   the motor is configured to drive the driving gear to rotate; the driving gear is configured to drive the driven gear to rotate; the driven gear is configured to push the regulator sliding members to move; and the regulator sliding members are configured to drive the regulator to rotate relative to the vaned diffuser, thus driving the regulator to move along its axis. In some embodiments, the regulator assembly further comprises a driven gear stopper;   the driven gear stopper is sleeved on the regulator, and is disposed between the driven gear and the vaned diffuser.       
 
         [0017]    In some embodiments, a bearing is disposed between the driven gear and the driven gear stopper. 
         [0018]    In some embodiments, grooves, which match with the rectangle-shaped through holes, are disposed on a periphery of the regulator; an axis of each groove is perpendicular to the axis of the driven gear; 
         [0019]    Each regulator sliding member is fixed in corresponding groove through corresponding rectangle-shaped through hole. 
         [0020]    In some embodiments, at least two rectangle-shaped through holes are arranged evenly along a circumference of the driven gear; 
         [0021]    the number of the grooves is identical to the number of the rectangle-shaped through holes. 
         [0022]    In some embodiments, the groove is provided with internal threads; 
         [0023]    the regulator sliding member is a bolt; the internal threads of the groove are engaged with and fixed with external threads of the regulator sliding member. 
         [0024]    In some embodiments, a sealing groove is disposed in a periphery of the supporting member; a sealing ring is disposed in the sealing groove. 
         [0025]    In some embodiments, length of the regulator is greater than length of the supporting member. 
         [0026]    A refrigeration compressor of the present disclosure comprises an impeller and the regulator assembly mentioned above. 
         [0027]    In some embodiments, an end of the regulator with external threads thereon is arranged near an outlet of the impeller;
       when the motor drives the driving gear to rotate forwardly, the driving gear drives the driven gear to rotate forwardly, and the end of the regulator with external threads thereon is retracted continuously, until the outlet of the impeller is opened completely; when the motor drives the driving gear to rotate reversibly, the driving gear drives the driven gear to rotate reversibly, and the end of the regulator with external threads thereon extends continuously, until the outlet of the impeller is closed completely.       
 
         [0029]    As compared with the prior art, the present disclosure has the beneficial effects as follows: the regulator assembly and the centrifugal compressor can realize a larger regulating range and have a wider range of applications; the outlet can be sealed completely, which prevents the refrigerant from flowing backwards to drive the impeller to rotate reversely, thereby avoiding the damage to the impeller; the regulator assembly is controlled independently, fewer transmission mechanisms are required, thus the transmission efficiency and the reliability are higher; the air flow direction and air flow rate at the inlet of the vaned diffuser are maintained unchanged, which reduces impact losses and avoids surges effectively; the overall structure of the regulator assembly is compact, and the regulator assembly is convenient to process and produce, and is convenient to refit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0030]      FIG. 1  is a schematic diagram illustrating the regulator assembly completely opened according to the first embodiment of the present invention; 
           [0031]      FIG. 2  is a partial schematic diagram illustrating the regulator assembly incompletely opened according to the first embodiment of the present invention; 
           [0032]      FIG. 3  is a partial schematic diagram illustrating the regulator assembly completely closed according to the first embodiment of the present invention; and 
           [0033]      FIG. 4  is a schematic diagram illustrating the regulator assembly completely opened according to the second embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0034]    In order to solve the problem of the too small regulating range, a regulator assembly is provided. 
         [0035]    The technical features above, additional technical features and the beneficial effects of the present invention will be described in more details with reference to the accompanying figures. 
         [0036]      FIG. 1  is a schematic diagram illustrating the regulator assembly completely opened according to the first embodiment of the present invention. As shown in  FIG. 1 , the regulator assembly comprises a motor  20 , a driving gear  31 , a driven gear  32 , a vaned diffuser  42  and a regulating mechanism. 
         [0037]    The motor  20  is rotatable forwardly and reversibly. 
         [0038]    Preferably, the driving gear  31  and the driven gear  32  are bevel gears. 
         [0039]    The driving gear  31  is connected with the motor  20 , and the motor  20  drives the driving gear  31  to rotate. As the driving gear  31  is engaged with the driven gear  32 , the driven gear  32  rotates synchronously. 
         [0040]    The regulating mechanism comprises a regulator  41 , a supporting member  43  and regulator sliding members  47 . 
         [0041]    The outer contour of the supporting member  43  is cylinder-shaped. 
         [0042]    The regulator  41  is formed through rotation machining, and has a through hole in the center. The regulator  41  is sleeved on the outer contour of the supporting member  43 . The length of the regulator  41  is greater than the length of the supporting member  43 . The supporting member  43  is disposed at the intermediate part of the regulator  41 , so that the regulator  41  can be supported more evenly. 
         [0043]    The motor  20  drives the driving gear  31  to rotate, and the driving gear  31  drives the driven gear  32  to rotate. The driven gear  32  pushes the regulator sliding members  47  to move, and the regulator sliding members  47  drive the regulator  41  to rotate relative to the vaned diffuser  42 , thus the regulator  41  moves along its axis. 
         [0044]    The driven gear  32  is sleeved on the regulator  41 , and the axis of the driven gear  32  is coincident with the axis of the regulator  41 . The driven gear  32  has rectangle-shaped through holes thereon, and the axis of each rectangle-shaped through hole is perpendicular to the axis of the driven gear  32 . The rectangle-shaped through hole extends along the axis of the driven gear  32 . At least two rectangle-shaped through holes are arranged in the driven gear  32 . In consideration of difficulties of the processing and balancing of forces acting on the driven gear, two rectangle-shaped through holes are preferably provided. 
         [0045]    The regulator sliding members  47  are fixed to the regulator  41  through the rectangle-shaped through holes, and the regulator sliding member is fixed with the regulator  41  through welding or is integrally formed with the regulator  41 . 
         [0046]    Preferably, grooves are provided at the proximal end of the regulator  41 , which is proximal to the driven gear  32 . The number of the grooves is identical to the number of the rectangle-shaped through holes, and the positions of the grooves arranged on the circumference of the regulator  41  correspond with the positions of the rectangle-shaped through holes. The regulator sliding member  47  is connected to the groove through the rectangle-shaped through hole in the driven gear  32 . This kind of structure is easy to process and the installation is fixed and stable. 
         [0047]    The groove may be provided with threads, and the regulator sliding member  47  may be provided with threads as well, so that the regulator sliding member  47  is connected with the groove reliably through threads. The regulator sliding member  47  is a screw or a bolt. The regulator  41  and the regulator sliding member  47 , as an integral assembly, move in the rectangle-shaped through hole in the axial direction of the regulator  41 . The length of the rectangle-shaped through hole determines the displacement distance in the axial direction. 
         [0048]    External threads are provided at the distal end of the regulator  41 , which is distal from the driven gear  32 . The vaned diffuser  42  is provided with internal threads. The vaned diffuser  42  is sleeved on the external threads of the regulator  41 , and is connected with the regulator  41  through threads. Meanwhile, the vaned diffuser  42  is fixed on the supporting member  43 . 
         [0049]    According to the description above, when the driven gear  32  rotates to drive the regulator  41  to rotate, the regulator  41  threadably engages with the vaned diffuser  42 , and the vaned diffuser  42  is positioned and fixed, and thus the rotation of the regulator  41  will make itself to move in the axial direction, and the regulator  41  is pushed forwards along the axial direction through the internal threads of the vaned diffuser  42 . When the motor  20  rotates reversibly, the motor drives the driving gear  31 , the driven gear  32  and the regulator  41  to rotate reversibly, and the regulator  41  moves backwards along the axial direction through the internal threads of the vaned diffuser  42 . 
         [0050]    The length of the external threads of the regulator  41  is designed according to actual requirements, and the length of the corresponding rectangle-shaped through hole in the driven gear  32  is adjusted accordingly, thereby realizing a wider regulating range and meeting different requirements under practical conditions. 
         [0051]    Preferably, in order to prevent the driven gear  32  from moving in the axial direction and ensure that the driven gear  32  is engaged with the driving gear  31 , a driven gear stopper  44  is arranged on the regulator  41 . The driven gear stopper  44  has a through hole in the center and is sleeved on the regulator  41 . 
         [0052]    Preferably, the regulating mechanism further comprises a position-limiting fastener  46 , which fixes the driven gear stopper  44  on the case  10 . 
         [0053]    The position-limiting fastener  46  may be a bolt, a positioning pin or a key in structure. Multiple position-limiting fasteners  46  may be arranged along the periphery of the driven gear stopper  44 . 
         [0054]    Preferably, a sealing groove is provided in a periphery of the supporting member  43  to contain a sealing ring  48 , which ensures a good sealing between the regulator  41  and the supporting member  43 . 
         [0055]    The regulator assembly is installed on the centrifugal compressor. The centrifugal compressor comprises a case  10 . The supporting member  43  is fixed on the case  10 . The end of the regulator  41  with external threads thereon is disposed near the outlet of the impeller  50 . The axial movement of the regulator  41  causes the expansion and contraction of the regulator  41 , thereby changing the outlet width of the impeller  50 . 
         [0056]    When the motor  20  drives the driving gear  31  to rotate forwardly, the driving gear  31  drives the driven gear  32  to rotate forwardly, and the end of the regulator  41  with external threads thereon is retracted continuously, until the outlet of the impeller  50  is opened completely. The state of the impeller  50  with the largest outlet width is shown in  FIG. 1 . 
         [0057]      FIG. 2  is a partial schematic diagram illustrating the regulator assembly incompletely opened according to the first embodiment of the present invention. As shown in  FIG. 2 , the regulator  41  of the regulator assembly is in a state of being incompletely opened. As shown in the figure, the directions denoted by the double-headed arrow are the directions in which the regulator  41  moves along its axis; the direction denoted by the single-headed arrow is the direction in which the refrigerant in the centrifugal compressor flows. 
         [0058]      FIG. 3  is a partial schematic diagram illustrating the regulator assembly completely closed according to the first embodiment of the present invention. When the motor  20  drives the driving gear  31  to rotate reversibly, the driving gear  31  drives the driven gear  32  to rotate reversibly, and the end of the regulator  41  with external threads thereon extends continuously, until the outlet of the impeller  50  is closed completely. 
         [0059]    When the regulator  41  extends to the farthest position, the outlet of the impeller  50  is sealed completely, which prevents the refrigerant from flowing backwards to drive the impeller  50  to rotate reversely. The regulator assembly does not need to use a check valve, thereby preventing the impeller  50  from rotating reversely to cause damages. 
         [0060]      FIG. 4  is a schematic diagram illustrating the regulator assembly completely opened according to the second embodiment of the present invention. The second embodiment differs from the first embodiment shown in  FIG. 1  in that: in the regulator assembly, a bearing  49  is provided between the driven gear  32  and the vaned diffuser  42 . 
         [0061]    Preferably, the bearing  49  is a thrust bearing. The frictional resistance of the thrust bearing is relatively smaller and the operating state of the thrust bearing is better. 
         [0062]    Conventional centrifugal compressors are mature products which are mass-produced in series. The regulator assembly may be installed in the existing space of the conventional centrifugal compressor by slightly refitting the existing vaned diffuser and the existing case. By slightly changing the dimension of the regulator  41 , the regulator  41  can be applied to impellers  50  with different diameters. The regulator assembly can be applied to centrifugal compressors with different powers, and has a wider range of applications. 
         [0063]    The present disclosure can regulate the outlet width of the impellers  50  precisely according to the operating conditions of applications, so as to form continuous and regulable width, enabling the centrifugal compressor to operate at the highest efficiency. 
         [0064]    The regulator assembly is controlled independently, fewer transmission mechanisms are required, and the transmission efficiency and the reliability are higher. Through regulating by the regulator assembly, it is ensured that the air flow direction and air flow rate at the inlet of the vaned diffuser  42  are maintained unchanged, which reduces impact losses and avoids surges effectively. The regulator assembly has high reliability, and the centrifugal compressor has a wider operating range. The overall structure of the regulator assembly is compact, and the regulator assembly is convenient to process and produce. 
         [0065]    Described above are several embodiments of the present invention, and they are specific and in details, but not intended to limit the scope of the present invention. It will be understood by those skilled in the art that various modifications and improvements can be made without departing from the concept of the present invention, and all these modifications and improvements are within the scope of the present invention.