JP2011052650A - Linear motor-driven compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high compression capability linear motor-driven compressor capable of fixing troubles such as power loss and decrease in durability due to diametrical displacement between each piston head and each piston rod while maintaining coolant compression capability per unit hour at a high level by employing a double-headed piston. <P>SOLUTION: The linear motor-driven compressor 100 comprises first and second cylinder blocks 1, 3, a shell 5, a center housing 7, first and second end plates 11, 13, a valve unit 25, a piston 27, first and second coil springs 49, 51, coils 63a, 63b, 65a, 65b, and permanent magnets 35, 37. The piston 27 comprises a piston rod 29, and first and second piston heads 31, 33. Between the shell 5 and the first and second cylinder blocks 1, 3, ensured are first and second gaps 1c, 3c for absorbing displacements G1, G2 between the center axis of the piston rod 27 and the center axis of the first and second piston heads 31, 33. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a linear electric compressor.

  A conventional linear electric compressor is disclosed in FIG. This linear electric compressor is provided between a housing in which a cylinder bore extends in the axial direction, a pair of end plates joined to both ends of the housing, and between the cylinder bore and each end plate. And a pair of valve units each having a discharge chamber and a suction chamber on each end plate side, a piston that is reciprocably accommodated in the cylinder bore, and that forms a compression chamber between each valve unit, and a piston in the cylinder bore. A spring having an urging force for reciprocating movement, a coil provided in the housing, and a permanent magnet provided in the piston for reciprocating the piston together with the spring by electromagnetic force generated by the coil. The piston is a double-headed piston comprising a piston rod and a piston head that is integrally provided at both ends of the piston rod and slidably contacts the inside of the cylinder bore.

  In this linear electric compressor, by periodically supplying power to the coil, an electromagnetic force that periodically changes around the coil is generated, and the permanent magnet of the piston is attracted to or separated from the electromagnetic force. For this reason, the piston reciprocates in the cylinder bore. At this time, the piston reciprocates also by resonance due to the natural frequency of the spring. By the reciprocation of the piston, the refrigerant is sucked into the compression chamber from the suction chamber, compressed in the compression chamber, and then discharged to the discharge chamber. For this reason, since this linear electric compressor can perform the compression action of a refrigerant by electric control, it is thought that it can be adopted as an air conditioner for an electric vehicle or the like. In addition, in this linear electric compressor, since it is possible to compress the refrigerant twice while the pistons of both heads reciprocate once, compared to the linear electric compressor that forms a compression chamber only at one end of the piston, The refrigerant compression capacity per unit time can be increased.

Japanese Patent No. 3953735

  However, in the above linear electric compressor, since the pistons of both heads are not an integral part and piston heads are assembled at both ends of the piston rod, there is a radial positional deviation between each piston head and the piston rod. Inevitable. For this reason, this piston is not easily slidably contacted within a single cylinder bore as it is, resulting in power loss due to frictional heat, deterioration in durability due to wear, and the like.

  The present invention has been made in view of the above-described conventional situation, and by adopting a double-headed piston, while maintaining a high refrigerant compression capacity per unit time, the central axis of each piston head and the piston rod It is an object to be solved to provide a linear electric compressor capable of solving problems such as power loss due to radial misalignment with the central shaft and a decrease in durability.

The linear electric compressor of the present invention is provided between a housing in which a cylinder bore extends in the axial direction, a pair of end plates joined to both ends of the housing, and between the cylinder bore and each end plate, The cylinder bore side is a compression chamber, each end plate side is a discharge chamber and / or a suction chamber, and the cylinder bore is reciprocally accommodated in the cylinder bore, and the compression unit is interposed between the valve units. A piston forming a chamber, a coil provided in the housing, and a permanent magnet provided in the piston and reciprocating the piston by electromagnetic force generated by the coil,
The housing has a first cylinder block through which a first cylinder bore which is the cylinder bore penetrates on one side, and a second cylinder block through which a second cylinder bore which is the cylinder bore penetrates on the other side,
The piston is provided integrally with a piston rod, one end of the piston rod, and is slidably brought into contact with the inside of the first cylinder bore, and is provided integrally with the other end of the piston rod, and is provided in the second cylinder bore. A second piston head in sliding contact with,
The first cylinder block and the second cylinder block have a diameter so as to absorb a radial displacement between the central axis of the piston rod and the central axes of the first piston head and the second piston head during assembly. It is comprised so that relative movement is possible in a direction (Claim 1).

  In the linear electric compressor of the present invention, the piston is a double-headed piston having the first and second piston heads, and the refrigerant can be compressed twice during one reciprocation. The compression capacity can be increased.

  The linear electric compressor has first and second cylinder blocks corresponding to the first and second piston heads, the first cylinder block has a first cylinder bore, and the second cylinder block has a second cylinder block. A cylinder bore is provided. For this reason, the first piston head makes sliding contact with the first cylinder bore, and the second piston head makes sliding contact with the second cylinder bore. For this reason, the position shift of the central axis between the first and second piston heads is absorbed by the first and second cylinder blocks moving in the radial direction. The first and second cylinder blocks move relative to each other in the radial direction when assembled, and absorb the positional deviation in the radial direction between the central axis of the piston rod and the central axis of the first and second piston heads. The first cylinder block and the second cylinder block cannot be moved relative to each other in the radial direction after being assembled. For this reason, the first and second piston heads of this piston are preferably slidably brought into contact with the first and second cylinder bores, and power loss due to frictional heat, durability deterioration due to wear, and the like are unlikely to occur.

  Therefore, this linear electric compressor uses a double-headed piston to maintain a high refrigerant compression capacity per unit time, while maintaining a high power loss due to radial displacement between each piston head and piston rod. It is possible to solve problems such as a decrease in durability.

  Further, in this linear electric compressor, the dimensional accuracy of the first and second cylinder blocks, the piston rod, and the first and second piston heads can be made equal to the conventional one, and an increase in manufacturing cost can be prevented.

  In this linear electric compressor, the housing may be provided radially outside the first cylinder block and the second cylinder block, and may have a shell that holds a coil between the first cylinder block and the second cylinder block. . In addition, the shell and the first cylinder block may be configured to be relatively movable in the radial direction so as to absorb a radial displacement between the central axis of the piston rod and the central axis of the first piston head during assembly. The shell and the second cylinder block can be configured to be relatively movable in the radial direction so as to absorb a radial displacement between the central axis of the piston rod and the central axis of the second piston head during assembly. Item 2).

  In this case, the shell and the first and second cylinder blocks move relative to each other in the radial direction when assembled, thereby absorbing the radial positional deviation between the central axis of the piston rod and the central axis of the first and second piston heads. can do. The shell and the first and second cylinder blocks cannot be moved relative to each other in the radial direction after being assembled.

  In this case, in the linear electric compressor, the first gap that absorbs the radial displacement between the central axis of the piston rod and the central axis of the first piston head is interposed between the shell and the first cylinder block. Can be secured. Further, it is preferable that a second gap that absorbs a radial displacement between the central axis of the piston rod and the central axis of the second piston head is secured between the shell and the second cylinder block (claim). Item 3). In this case, the first and second gaps can absorb radial displacement between the central axis of the piston rod and the central axis of the first and second piston heads. The shell and the first and second cylinder blocks can be relatively moved in the radial direction within the first and second gaps when assembled. For this reason, the range in which the shell and the first and second cylinder blocks can move relative to each other can be easily adjusted by changing the size of the first and second gaps. It should be noted that the first and second gaps may be configured to remain after absorbing each positional shift, or may be configured not to remain.

  Furthermore, in the linear electric compressor in this case, it is preferable that the first cylinder block and the second cylinder block are fixed so as not to rotate relative to the shell. In this case, the piston is prevented from rolling, and the first and second piston heads can be slidably contacted in the first and second cylinder bores.

  In this linear electric compressor, a first bolt hole extending in the axial direction may be formed in the first cylinder block, and a second bolt hole extending in the axial direction may be formed in the second cylinder block. Further, bolts for fastening the first cylinder block and the second cylinder block can be inserted into the first bolt hole and the second bolt hole. And the 1st clearance gap which absorbs the position shift of the diameter direction of the central axis of a piston rod and the central axis of the 1st piston head can be secured between the 1st bolt hole and a bolt. Further, a second gap that absorbs a radial displacement between the center axis of the piston rod and the center axis of the second piston head can be secured between the second bolt hole and the bolt.

  In this case, the first and second cylinder blocks are fastened by bolts. The first and second cylinder blocks can be moved relative to each other in the radial direction within the first and second gaps, which are gaps between the first and second bolt holes. For this reason, the range in which the first and second cylinder blocks can be relatively moved can be easily adjusted by changing the sizes of the first and second bolt holes and the bolts. It should be noted that the first and second gaps may be configured to remain after absorbing each positional shift, or may be configured not to remain.

  In this linear electric compressor, the first gap is larger than the radial displacement between the center axis of the piston rod and the center axis of the first piston head, and the second gap is the center axis of the piston rod and the second piston head. It is preferably larger than the positional deviation in the radial direction with respect to the central axis. In this case, the first gap completely absorbs the positional deviation between the central axis of the piston rod and the central axis of the first piston head, and the second gap is a position between the central axis of the piston rod and the central axis of the second piston head. Fully absorb the deviation. For this reason, the first and second piston heads of this piston are most preferably in sliding contact with the first and second cylinder bores. For this reason, it is hard to produce the power loss by friction heat, the fall of durability by abrasion, etc. more.

  Further, the linear electric compressor may include an urging member having an urging force for reciprocating the piston in the cylinder bore. The housing may have a center housing provided between the first cylinder block and the second cylinder block and forming a spring seat around the piston rod. And it is preferable that the coil spring as an urging | biasing member is provided between the spring seat and both piston heads (Claim 7). In this case, in addition to the electromagnetic force generated by the coil, the piston can be reciprocated by resonance due to the natural frequency of the biasing member. In addition, since a coil spring as an urging member is provided in the piston, a large compression chamber or the like can be secured. For this reason, even if the linear electric compressor is downsized, the compression efficiency of the refrigerant can be maintained high.

1 is a cross-sectional view showing a linear electric compressor of Example 1. FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic structural diagram showing a vehicle air conditioner using linear electric compression according to a first embodiment. It is sectional drawing which expands and shows a part of linear electric compressor of Example 1. FIG. It is explanatory drawing which shows the coil and permanent magnet in the linear electric compressor of Example 1. FIG. In the linear electric compressor of Example 1, it is a schematic cross section which shows the positional relationship of a piston and each cylinder block. In the linear electric compressor of Example 2, it is a schematic cross section which shows the positional relationship of a piston and each cylinder block.

  Embodiments 1 and 2 embodying the present invention will be described below with reference to the drawings.

Example 1
A linear electric compressor 100 according to the first embodiment shown in FIG. 1 is employed as an air conditioner for a hybrid vehicle or an electric vehicle. In this linear electric compressor 100, a housing 9 is constituted by first and second cylinder blocks 1, 3, a shell 5 and a center housing 7. A first cylinder bore 1a extends through the first cylinder block 1 in the axial direction, and a second cylinder bore 3a extends through the second cylinder block 3 in the axial direction. The first and second cylinder bores 1a and 3a are designed to be coaxial and have the same diameter.

  The first and second cylinder blocks 1 and 3 have flanges 1b and 3b around the first and second cylinder bores 1a and 3a, and are accommodated in the shell 5 so that the flanges 1b and 3b are located at both ends. . At this time, as shown in FIGS. 3 and 5, the first cylinder block 1 is accommodated in the shell 5 so as to secure a first gap 1 c between the flange 1 b and the shell 5. Similarly, the second cylinder block 3 is accommodated in the shell 5 such that a second gap 3c is secured between the flange 3b and the shell 5.

  The shell 5 and the first and second cylinder blocks 1 and 3 are relatively movable in the radial direction when assembled as the linear electric compressor 100. The first and second cylinder blocks 1 and 3 can be rotated relative to each other when assembled as the linear electric compressor 100. On the other hand, the shell 5 and the first and second cylinder blocks 1 and 3 are not relatively movable in the radial direction after being assembled as the linear electric compressor 100. Further, the first and second cylinder blocks 1 and 3 are not rotatable relative to the shell 5 when assembled as the linear electric compressor 100.

  As shown in FIG. 1, a center housing 7 is provided between the first and second cylinder blocks 1 and 3 in the shell 5. The center housing 7 is provided with a receiving hole 7a that is coaxial with and has the same diameter as the first and second cylinder bores 1a and 3a.

  First and second end plates 11 and 13 are joined to both ends of the shell 5 via first and second gaskets 10 and 12. A space is formed in the first and second end plates 11, 13. A first valve plate 15 is sandwiched between the first gasket 10 and the first end plate 11, and the second gasket 12 and the second end are sandwiched between the first gasket 10 and the first end plate 11. A second valve plate 17 is sandwiched between the plate 13. The spaces of the first and second end plates 11 and 13 are defined as first and second discharge chambers 11a and 13a by first and second valve plates 15 and 17, respectively. The first and second end plates 11 and 13 are provided with first and second discharge ports 11b and 13b. The first discharge chamber 11a is connected to the pipe 101 shown in FIG. 2 by the first discharge port 11b, and the second discharge chamber 13a is connected to the pipe 102 by the second discharge port 13b.

  As shown in FIG. 1, the first valve plate 15 is provided with a discharge port 15 a. Further, on the first discharge port 11 b side of the first valve plate 15, a lead type discharge valve 19 that can open and close the discharge port 15 a and a retainer 21 that regulates the opening degree of the discharge valve 19 are provided by a rivet 23. ing. The first valve plate 15, the discharge valve 19, the retainer 21, and the rivet 23 are the first valve unit 25. The same applies to the second valve plate 17 side.

  As shown in FIG. 1, pistons 27 are accommodated in the first and second cylinder bores 1a, 3a and the accommodation hole 7a so as to be reciprocally movable. The piston 27 is provided integrally with the piston rod 29, one end of the piston rod 29, the first piston head 31 slidably contacting the inside of the first cylinder bore 1a, and the other end of the piston rod 29. The second piston head 33 is in sliding contact with the cylinder bore 3a. Thus, the piston 27 is not an integral part. That is, as shown in FIG. 5, the piston 27 has the first and second piston heads 31 and 33 assembled at both ends of the piston rod 29, so that the central axis of the first piston head 31 and the center of the piston rod 29 A radial displacement G1 is inevitably generated between the shaft and the shaft, and a radial displacement G2 is inevitably generated between the central axis of the second piston head 33 and the central axis of the piston rod 29. ing. The first gap 1c is larger than the positional deviation G1, and the second gap 3c is larger than the positional deviation G2.

  As shown in FIGS. 3 and 4, the first piston head 31 is provided integrally with a head main body 39 that fixes permanent magnets 35 and 37 on the outer peripheral surface, and the head main body 39, and is formed on the inner surface of the first cylinder bore 1 a. On the other hand, the first and second spacers 41 and 43 that separate the outer peripheral surfaces of the permanent magnets 35 and 37 are provided.

  The permanent magnets 35 and 37 are cylindrical. The permanent magnets 35 and 37 are made of rare earth magnets. The permanent magnet 35 has an N pole on the outer peripheral surface side and an S pole on the inner peripheral surface side, and the permanent magnet 37 has an S pole on the outer peripheral surface side and an N pole on the inner peripheral surface side. The permanent magnet 35 may have an S pole on the outer peripheral surface side and an N pole on the inner peripheral surface side, and the permanent magnet 37 may have an N pole on the outer peripheral surface side and an S pole on the inner peripheral surface side.

  As shown in FIG. 3, the second spacer 43 is press-fitted into the head main body 39, then the permanent magnets 37 and 35 are inserted into the head main body 39, and then the first spacer 41 is press-fitted into the head main body 39, so that Magnets 35 and 37 are sandwiched between first and second spacers 41 and 43 on head body 39. The first piston head 31 has a compression chamber 45 on the first spacer 41 side.

  The head body 39 is provided with a suction port 39a that opens from the inside toward the compression chamber 45. The first spacer 41 is formed with a valve port 41a communicating with the suction port 39a, and a float type suction valve 47 is accommodated in the valve port 41a. The valve port 41a has a locking piece 41b on the compression chamber 45 side. On the outer peripheral edge of the suction valve 47, there are formed a plurality of locking pieces 47a that come into contact with the locking piece 41b when the suction port 39a is opened, and notches 47b are formed between the locking pieces 47a.

  As shown in FIG. 1, a first piston head 31 and a second piston head 33 are press-fitted into both ends of the piston rod 29. The piston rod 29 has a smaller diameter than the first and second piston heads 31 and 33. The piston rod 29 is formed with a suction passage 29a that opens radially in the center and extends in the axial direction. As shown in FIG. 4, the suction passage 29 a communicates with the suction port 39 a of the first piston head 31. The suction passage 29a, the suction port 39a, the suction valve 47, and the first spacer 41 constitute a suction valve mechanism 50. The same applies to the second piston head 33 side.

  As shown in FIG. 1, a spring seat 7b is formed in the center housing 7 at a central position at the same distance from the end faces of the first and second cylinder blocks 1 and 3 so as to protrude into the storage hole 7a. Yes. A space between the inner surface of the storage hole 7a and the outer peripheral surface of the piston rod 29 is a spring chamber 7c. First and second coil springs 49 and 51 as urging members are accommodated in the spring chamber 7c.

  In the pre-compressed state, the first coil spring 49 has one end abutting against the spring seat 7 b and the other end abutting against the second spacer 43 of the first piston head 31. Similarly, the second coil spring 51 is in a pre-compressed state, and has one end abutting against the spring seat 7 b and the other end abutting against a second spacer (no symbol) of the second piston head 33.

  An intermediate chamber 53 is formed between the center housing 7 and the shell 5. The center housing 7 has a communication hole 7d penetrating the intermediate chamber 53 and the spring chamber 7c. The intermediate chamber 53 and the spring chamber 7 c correspond to the suction chamber 55. The shell 5 is provided with a suction port 5a. The suction chamber 55 is connected to the pipe 103 shown in FIG. 2 by a suction port 5a. A cover 57 for closing the intermediate chamber 53 is also fixed to the shell 5, and terminals (not shown) connected to coils 63 a, 63 b, 65 a, 65 b described later are fixed to the cover 57.

  Coils 63 a, 63 b, 65 a, 65 b are provided between the first and second cylinder blocks 1, 3 and the shell 5 while being held by the first and second holding members 59, 61. The coils 63a, 63b, 65a, 65b are provided around the first and second piston heads 31, 33. The first and second cylinder blocks 1 and 3 and the first and second holding members 59 and 61 are made of a magnetic material. The first and second gaps 1 c and 3 c are also secured between the first and second holding members 59 and 61 and the shell 5. The first and second cylinder blocks 1 and 3 can also be made of a nonmagnetic material.

  As shown in FIG. 2, the linear electric compressor 100 has a pipe 101 and a pipe 102 connected to a pipe 104, and the pipe 104 is connected to a condenser 105. The condenser 105 is connected to the expansion valve 107 and the evaporator 108 by a pipe 106, and the evaporator 108 is connected to the pipe 103. The terminal in the intermediate chamber 53 is connected to the power feeding device 110 by a lead wire 109. The power feeding device 110 is electrically controlled.

  In the linear electric compressor 100 configured as described above, the power supply device 110 periodically supplies power to the coils 63a, 63b, 65a, and 65b, thereby periodically changing around the coils 63a, 63b, 65a, and 65b. To generate electromagnetic force. At this time, as shown in FIG. 4, if the coil 63 a attracts the permanent magnet 35 of the first piston head 31, the coil 63 b tries to separate the permanent magnet 37 of the first piston head 31. Conversely, if the coil 63 a pulls away the permanent magnet 35 of the first piston head 31, the coil 63 b tries to attract the permanent magnet 37 of the first piston head 31. For this reason, in this linear electric compressor 100, it is possible to reciprocate the piston 27 with a large thrust. In particular, in the linear electric compressor 100, since the permanent magnets 35 and 37 are rare earth magnets, the thrust is large while being small.

  Therefore, the permanent magnets 35 and 37 of the piston 27 (only the permanent magnet of the first piston head 31 is indicated by a symbol) are attracted to or separated from the electromagnetic force generated by 63a, 63b, 65a, and 65b. For this reason, the piston 27 reciprocates in the first and second cylinder bores 1a and 3a. At this time, the piston 27 reciprocates also by resonance due to the natural frequency of the first and second coil springs 49 and 51.

  By the reciprocating motion of the piston 27, the respective steps of refrigerant suction, compression, and discharge are performed. The first piston head 31 side will be described in detail as an example. As shown in FIG. 3, when the first piston head side 31 is in the suction stroke, the pressure in the compression chamber 45 becomes low, the suction valve 47 moves in the valve port 41, and the suction port 39a is opened. For this reason, the refrigerant in the suction chamber 55 passes through the gap between the notch 47b of the suction valve 47 and the locking piece 41b from the suction port 39a and is sucked into the compression chamber 45. At this time, the discharge port 15 a is closed by the discharge valve 19.

  When the first piston head side 31 shifts to the compression stroke, the suction valve 47 moves in the valve port 41a by the pressure in the compression chamber 45, and the suction port 39a is closed. And when the pressure in the compression chamber 45 rises, the discharge valve 19 is opened. That is, the first piston head side 31 shifts to the discharge stroke. Thus, the compressed refrigerant is discharged to the discharge chamber 11a through the discharge port 15a. Although the refrigerant in the discharge chamber 11a is hot, the gasket 10 exists between the first end plate 11 and the first cylinder block 1, and the piston 27 is not in direct contact with the discharge chamber 11a. For this reason, the piston 27 is hardly heated by the refrigerant in the discharge chambers 11a and 13a. The same applies to the second piston head 33 side.

  In this way, the refrigerant circulates as follows to air-condition the vehicle interior. That is, the refrigerant discharged from the evaporator 108 to the pipe 103 is sucked into the compression chamber 45 from the suction chamber 55, compressed in the compression chamber 45, and then discharged into the first and second discharge chambers 11a and 13a. The refrigerant in the first and second discharge chambers 11 a and 13 a reaches the condenser 105, the expansion valve 107 and the evaporator 108 through the pipes 101 and 102. Since these linear electric compressors 100 can perform a refrigerant compression action by electric control, it is possible to perform air conditioning suitably as an air conditioner for an electric vehicle or the like. For example, even if the vehicle is equipped with a hybrid engine and the engine is stopped while the vehicle is stopped, the linear electric compressor 100 can provide suitable air conditioning.

  Further, in this linear electric compressor 100, since the refrigerant can be compressed twice while the piston 27 reciprocates once, compared with the linear electric compressor that forms a compression chamber only at one end of the piston, The refrigerant compression capacity per unit time can be increased.

  The linear electric compressor 100 has first and second cylinder blocks 1 and 3 corresponding to the first and second piston heads 31 and 33, respectively, and a first cylinder bore 1a is provided through the first cylinder block 1, A second cylinder bore 3 a is provided through the second cylinder block 3. Therefore, in the piston 27, the first piston head 31 is in sliding contact with the first cylinder bore 1a, and the second piston head 33 is in sliding contact with the second cylinder bore 3a. For this reason, the radial displacement (G1 + G2) of the central axis between the first and second piston heads 31 and 33 is absorbed by the first and second cylinder blocks 1 and 3 moving in the radial direction.

  As shown in FIG. 5, in this linear electric compressor 100, the shell 5 and the first and second cylinder blocks 1 and 3 move relative to each other in the radial direction when assembled, and the first and second cylinder blocks 1 First and second gaps 1c and 3c are secured between the first and second shells 5 and the shell 5. For this reason, the radial displacement G1 between the central axis of the piston rod 29 and the central axis of the first piston head 31 is absorbed in the first gap 1c when the shell 5 and the first cylinder block 1 are assembled. Further, the radial displacement G2 between the central axis of the piston rod 29 and the central axis of the second piston head 33 is absorbed by the second gap 3c when the shell 5 and the second cylinder block 3 are assembled. For these reasons, the first and second piston heads 31 and 33 of the piston 27 are preferably in sliding contact with the first and second cylinder bores 1a and 3a.

  In particular, in this linear electric compressor 100, the shell 5 and the first and second cylinder blocks 1 and 3 can be relatively moved in the radial direction in the range of the first and second gaps 1c and 3c when assembled. For this reason, by changing the size of the first and second gaps 1c and 3c, it is possible to easily adjust the range in which the shell 5 and the first and second cylinder blocks 1 and 3 can relatively move when assembled. Further, since the first gap 1c is larger than the positional deviation G1, and the second gap 3c is larger than the positional deviation G2, the first gap 1c completely absorbs the positional deviation G1, and the second gap 3c eliminates the positional deviation G2. Absorb completely. Therefore, the first and second piston heads 31 and 33 of the piston 27 are most preferably in sliding contact with the first and second cylinder bores 1a and 3a. For this reason, the linear electric compressor 100 is less likely to cause power loss due to frictional heat, deterioration in durability due to wear, and the like. Since the first and second gaps 1c and 3c are larger than the positional deviations G1 and G2, some of the first and second gaps 1c and 3c remain even after the positional deviations G1 and G2 are absorbed.

  Therefore, this linear electric compressor 100 employs the double-headed piston 27 to maintain the refrigerant compression capacity per unit time high, while maintaining the central axes of the first and second piston heads 31 and 33 and the piston rod 29. It is possible to solve problems such as power loss and deterioration in durability due to a radial positional deviation from the central axis.

  Further, in this linear electric compressor 100, the dimensional accuracy of the shell 5, the first and second cylinder blocks 1, 3, the piston rod 29 and the first and second piston heads 31, 33 can be made equal to the conventional one, An increase in manufacturing cost can be prevented.

  Further, in this linear electric compressor 100, the first and second cylinder blocks 1, 3 are fixed to the shell 5 so as not to rotate relative to each other. For this reason, the rolling of the piston 27 is prevented, and the first and second piston heads 31 and 33 can be stably brought into sliding contact within the first and second cylinder bores 1a and 3a.

  In this linear electric compressor 100, the housing 9 has a center housing 7 provided between the first cylinder block 1 and the second cylinder block 3 and forming a spring seat 7c around the piston rod 27. ing. In addition, first and second coil springs 49 and 51 as urging members are provided between the spring seat 7c and the first and second piston heads. For this reason, since the 1st, 2nd coil springs 49 and 51 as an urging | biasing member can be provided in the piston 27, the compression chamber 45 can be ensured large. For this reason, even if the linear electric compressor 100 is downsized, the compression efficiency of the refrigerant can be maintained high.

(Example 2)
As shown in FIG. 6, the linear electric compressor 200 according to the second embodiment is configured such that the first and second cylinder blocks 1e and 3e are relatively movable in the radial direction. In FIG. 6, illustration of the shell 5 is omitted.

  More specifically, a plurality of first bolt holes 71 extending in the axial direction are formed in the first cylinder block 1e and the first end plate 11a. A plurality of second bolt holes 73 extending in the axial direction are formed in the second cylinder block 3e and the second end plate 13a. Through bolts 67 are inserted into the first and second bolt holes 71 and 73, respectively. The first and second cylinder blocks 1e and 3e and the first and second end plates 11a and 13a are fastened by through bolts 67 and assembled as a linear electric compressor 200. The first and second cylinder blocks 1e and 3e are immovable relative to each other in the radial direction after being fastened, that is, after being assembled as the linear electric compressor 200.

  A first gap 1 f is secured between each first bolt hole 71 and each through bolt 67. A second gap 3 f is secured between each second bolt hole 73 and each through bolt 67. The first gap 1f is larger than the radial displacement G1 between the center axis of the piston rod 29 and the center axis of the first piston head 31, and the second gap 3f is the center axis of the piston rod 29 and the center of the second piston head 33. It is larger than the positional deviation G2 in the radial direction from the shaft. Other configurations are the same as those of the first embodiment, and the same components are denoted by the same reference numerals, and detailed description of the configurations is omitted.

  In this linear electric compressor 200, when the first and second cylinder blocks 1e and 3e are fastened, the radial displacement (G1 + G2) of the central axis between the first and second piston heads 31 and 33 is absorbed. Therefore, the first and second piston heads 31 and 33 of the piston 27 are preferably in sliding contact with the first and second cylinder bores 1a and 3a.

  In particular, in this linear electric compression 200, a first bolt hole 71 is formed in the first cylinder block 1e, and a second bolt hole 73 is formed in the second cylinder block 3e. A through bolt 67 is inserted through the first and second bolt holes 71 and 73. Further, a first gap 1 f is secured between the first bolt 71 hole and the through bolt 67, and a second gap 3 f is secured between the second bolt hole 73 and the through bolt 67. For this reason, when the first and second cylinder blocks 1e and 3e are fastened by the through bolts 67, the first cylinder block 1e can be relatively moved in the radial direction within the range of the first gap 1f. Similarly, the second cylinder block 3e can be relatively moved in the radial direction within the range of the second gap 3f. For this reason, when the first cylinder block 1e and the second cylinder block 3e are fastened, the respective radial position shifts G1, G2 between the central axis of the piston rod 27 and the central axes of the first and second piston heads 31, 33 are provided. Can be absorbed in the first and second gaps 1f and 3f, respectively. For these reasons, the first and second piston heads 31 and 33 of the piston 27 are preferably in sliding contact with the first and second cylinder bores 1a and 3a.

  In this linear electric compressor 200, the first and second cylinder blocks 1e and 3e have a diameter within a range of first and second gaps 1f and 3f which are gaps between the first and second bolt holes 71 and 73 and the through bolt 67. Relative movement in the direction is possible. For this reason, by changing the sizes of the first and second bolt holes 71 and 73 and the through bolt 67, the range in which the first and second cylinder blocks 1e and 3e can be relatively moved can be easily adjusted. Further, since the first gap 1f is larger than the positional deviation G1, and the second gap 3f is larger than the positional deviation G2, the first gap 1f completely absorbs the positional deviation G1, and the second gap 3f completely eliminates the positional deviation G2. Absorb. Therefore, the first and second piston heads 31 and 33 of the piston 27 are most preferably in sliding contact with the first and second cylinder bores 1a and 3a. Since the first and second gaps 1f and 3f are larger than the positional deviations G1 and G2, a part of the first and second gaps 1f and 3f remains even after the positional deviations G1 and G2 are absorbed. Other functions and effects are the same as those of the first embodiment.

  In the above, the present invention has been described with reference to the first and second embodiments. However, the present invention is not limited to the above-described embodiments, and it goes without saying that the present invention can be appropriately modified and applied without departing from the spirit of the present invention. Absent.

  For example, the linear electric compressor of the present invention may be used in combination with other compressors in addition to the case where it is used alone.

  The first and second spacers 41 and 43 can also be made of a fluororesin such as PTFE. In this case, the piston 27 preferably slides in the first and second cylinder bores 1a and 3a.

  The intake valve mechanism 50 may employ a lead type intake valve.

  The present invention can be mounted on an electric vehicle using an electric motor in addition to a hybrid vehicle. Moreover, it cannot be overemphasized that it can mount in the motor vehicle using an engine.

DESCRIPTION OF SYMBOLS 1a, 3a ... Cylinder bore 9 ... Housing (1, 1e ... 1st cylinder block, 3, 3e ... 2nd cylinder block, 5 ... Shell, 7 ... Center housing)
11, 11a, 13, 13a ... end plate (11, 11a ... first end plate, 13, 13a ... second end plate)
45 ... Compression chamber 11a, 13a ... Discharge chamber (11a ... First discharge chamber, 13a ... Second discharge chamber)
55 ... Suction chamber (7c ... Spring chamber, 53 ... Intermediate chamber)
25 ... Valve unit 27 ... Piston 63a, 63b, 65a, 65b ... Coil 35, 37 ... Permanent magnet 29 ... Piston rod 31, 33 ... Piston head (31 ... First piston head, 33 ... Second piston head)
G1, G2 ... Misalignment 100, 200 ... Linear electric compressor 1c ... First gap 3c ... Second gap 71 ... First bolt hole 73 ... Second bolt hole 67 ... Through bolt 49, 51 ... Biasing member (49 ... 1st coil spring, 51 ... 2nd coil spring)
7b ... Spring seat

Claims (7)

A housing in which a cylinder bore extends in an axial direction, a pair of end plates joined to both ends of the housing, a cylinder bore and each end plate are provided, and the cylinder bore side serves as a compression chamber. A pair of valve units having a discharge chamber and / or a suction chamber on the end plate side, a piston which is reciprocably accommodated in the cylinder bore, and forms the compression chamber between the valve units, and a housing A coil provided and a permanent magnet provided on the piston and reciprocating the piston by electromagnetic force generated by the coil;
The housing has a first cylinder block through which a first cylinder bore which is the cylinder bore penetrates on one side, and a second cylinder block through which a second cylinder bore which is the cylinder bore penetrates on the other side,
The piston is provided integrally with a piston rod, one end of the piston rod, and is slidably in contact with the first cylinder bore, and is provided integrally with the other end of the piston rod. A second piston head in sliding contact with,
The first cylinder block and the second cylinder block have a diameter so as to absorb a radial displacement between the central axis of the piston rod and the central axes of the first piston head and the second piston head during assembly. A linear electric compressor characterized by being configured to be relatively movable in a direction. The housing is provided on a radially outer side of the first cylinder block and the second cylinder block, and has a shell for holding the coil between the first cylinder block and the second cylinder block,
The shell and the first cylinder block are configured to be relatively movable in the radial direction so as to absorb a radial displacement between the central axis of the piston rod and the central axis of the first piston head when assembled.
The shell and the second cylinder block are configured to be relatively movable in the radial direction so as to absorb a radial displacement between the central axis of the piston rod and the central axis of the second piston head during assembly. The linear electric compressor according to claim 1. A first gap is secured between the shell and the first cylinder block to absorb a radial displacement between the central axis of the piston rod and the central axis of the first piston head.
3. A second gap is secured between the shell and the second cylinder block to absorb radial displacement between the central axis of the piston rod and the central axis of the second piston head. The linear electric compressor as described.   The linear electric compressor according to claim 2 or 3, wherein the first cylinder block and the second cylinder block are fixed so as not to rotate relative to the shell. A first bolt hole extending in the axial direction is formed in the first cylinder block, and a second bolt hole extending in the axial direction is formed in the second cylinder block. The first bolt hole and the second bolt Bolts for fastening the first cylinder block and the second cylinder block are inserted into the holes,
A first gap is secured between the first bolt hole and the bolt to absorb a radial displacement between the central axis of the piston rod and the central axis of the first piston head.
2. A second gap is secured between the second bolt hole and the bolt to absorb a radial displacement between the central axis of the piston rod and the central axis of the second piston head. The linear electric compressor as described.   The first gap is larger than the radial displacement between the central axis of the piston rod and the central axis of the first piston head, and the second gap is the center of the piston rod and the center of the second piston head. The linear electric compressor according to claim 3 or 5, wherein the linear electric compressor is larger than a radial positional deviation with respect to the shaft. An urging member having an urging force for reciprocating the piston in the cylinder bore;
The housing is provided between the first cylinder block and the second cylinder block, and has a center housing that forms a spring seat around the piston rod, and between the spring seat and both the piston heads. The linear electric compressor according to claim 1, wherein a coil spring is provided as the biasing member.

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