JP2008184947A - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electric compressor capable of enhancing the cooling efficiency of an electronic component in an inverter assembly. <P>SOLUTION: An electric compressor 10 is equipped with a motor chamber 27 provided in a suction pressure region. The motor chamber 27 is adjacent to an inverter accommodation chamber 101 with a first housing 24 in between. A cooling hole 130 extending from the motor chamber 27 toward the inverter accommodation chamber 101 is formed in a first housing 24 and taken as a through-hole passing therethrough. A cooling medium in the motor chamber 27 flows into the cooling hole 130 and comes into contact with a heat transfer plate 110, thereby cooling the heat transfer plate 110 directly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric compressor, and more particularly to an inverter that drives an electric motor.

  2. Description of the Related Art An electric compressor having a compression mechanism is known that includes an electric motor that drives the compression mechanism, and further includes an inverter that controls and drives the electric motor. Such an electric compressor accommodates and fixes an inverter in an inverter accommodation chamber. Such an electric compressor has a configuration in which each member of the inverter is fixed in a non-removable manner, and is disclosed in Patent Document 1, for example.

Japanese Patent Laid-Open No. 2004-197688

However, the inverter of the conventional electric compressor as shown in Patent Document 1 has a problem that the cooling efficiency of the electronic components included in the inverter, particularly the switching element, is relatively low.
For this reason, for example, when using a switching element with a low heat-resistant temperature, temperature protection is required, and the configuration becomes complicated. In addition, when a switching element having a high heat-resistant temperature is used, the cost and the size of the configuration are increased.

  The present invention has been made to solve such problems, and an object thereof is to provide an electric compressor capable of improving the cooling efficiency of electronic components of an inverter assembly.

  In order to solve the above-described problems, an electric compressor according to the present invention is provided with a compression mechanism portion that sucks fluid from a suction pressure region, an electric motor that drives the compression mechanism portion, and a suction pressure region. An inverter assembly for controlling the number of revolutions of the electric motor, and an inverter housing chamber for accommodating the inverter assembly. The assembly includes a board having an electric circuit, an electronic component connected to the board, and a base that supports the board, and is detachably fixed in the inverter accommodating chamber. The motor chamber and the inverter accommodating chamber sandwich the housing. In the adjacent electric compressor in the housing, the housing has a through hole extending from the motor chamber to the inverter accommodating chamber. Is formed, one end of the through hole base in contact, around the through hole, and the motor housing chamber and the inverter accommodation chamber, characterized in that it is sealed.

  According to this electric compressor, the refrigerant in the motor chamber that is in the suction pressure region, that is, the low temperature side, flows into the through-hole, passes through the housing, and contacts the base. As a result, the base is directly cooled around the through hole. The base functions as a heat transfer plate and further cools the electronic components.

The motor housing chamber and the inverter housing chamber may be sealed using an O-ring.
By setting it as such a structure, a motor storage chamber and an inverter storage chamber can be sealed reliably.
The electronic component may include a switching element, and the through hole may be provided in the vicinity of the switching element.
By setting it as such a structure, a switching element can be cooled more efficiently. Of the elements that make up electronic components, switching elements are more likely to be hotter than other components, so if the switching elements can be cooled pinpoint in this way, the entire electronic component can be cooled more efficiently. Can do.
The inverter assembly may further include a base that supports the substrate, and the base may contact one end of the through hole.
By setting it as such a structure, the base which is a heat exchanger plate can be utilized also as a structure for sealing a motor storage chamber and an inverter storage chamber, and a structure becomes simple.

According to the present invention, since the refrigerant in the suction pressure region contacts the heat transfer plate of the inverter assembly through the cooling hole and directly cools the heat transfer plate, the cooling efficiency of the electronic components of the inverter assembly is improved. be able to.
Thereby, for example, a switching element having a high heat-resistant temperature is not necessary, and high cost and an increase in size of the configuration can be avoided. Further, for example, even a switching element having a low heat resistance temperature does not require temperature protection, and the configuration is simplified.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
FIG. 1 shows an electric compressor 10 according to Embodiment 1 of the present invention.
The electric compressor 10 includes a first housing 24 and a second housing 25. The first housing 24 and the second housing 25 are fixed to each other by a bolt 16. The first housing 24 has a bottomed cylindrical shape including a cylindrical portion 24f and a bottom portion 24g, and a cylindrical shaft support portion 24h is provided on the bottom portion 24g.
In FIG. 1, the right side of the drawing, ie, the second housing 25 side is defined as the front, and the left side of the drawing, ie, the bottom 24g side of the first housing 24 is defined as the rear.

The electric compressor 10 includes a fixed scroll 11, a turning scroll 12, and a compression chamber 13 formed by the fixed scroll 11 and the turning scroll 12. The fixed scroll 11 includes a disk-shaped fixed base 11a, a spiral fixed wrap 11b erected from the fixed base 11a, and a fixed wrap outermost wall 11c. A discharge port 47 is provided in the center of the fixed base 11a.
In the electric compressor 10, the compression mechanism section includes a fixed scroll 11, a turning scroll 12, and a compression chamber 13, sucks fluid from the suction pressure region, compresses it, and discharges it to the discharge pressure region. Here, the suction pressure region is a region through which the fluid sucked from the outside of the electric compressor 10 passes before flowing into the compression chamber 13, and the discharge pressure region is the fluid compressed in the compression chamber 13. This is a region through which the electric compressor 10 passes before it flows out.

  The orbiting scroll 12 includes a disc-shaped orbiting base 12a and a spiral orbiting wrap 12b provided upright from the orbiting base 12a. A cylindrical holding portion 12c is provided.

The electric compressor 10 further includes a drive crank mechanism 19 that causes the orbiting scroll 12 to perform orbiting motion (revolution motion) and a pin 20 that prevents the orbiting scroll 12 from rotating. The pin 20 is attached to the shaft support member 15 and is provided so as to loosely fit into the annular recess 12 d of the orbiting scroll 12.
The drive crank mechanism 19 includes a holding portion 12 c, a crank pin 22 a of the drive shaft 22, and a ball bearing 17 that supports the crank pin 22 a via the bush 18.

  The drive shaft 22 passes through the center of the electric motor 26. The electric motor 26 drives the compression mechanism, and includes a drive shaft 22, a rotor 28 fitted into the drive shaft 22, and a stator 30 that is provided on the outer peripheral side and around which a coil 29 is wound. Is a three-phase synchronous motor.

A part of the first housing 24 is recessed on the outer surface near the rear side of the first housing 24 to provide the inverter accommodating chamber 101. The electric compressor 10 includes an inverter assembly 100 housed in the inverter housing chamber 101. The detailed configuration of the inverter assembly 100 will be described later with reference to FIG. 2, and only the heat transfer plate 110 is shown in FIG. 1 for simplicity.
The inverter assembly 100 is electrically connected to the electric motor 26 via an airtight terminal 122 (described later with reference to FIG. 2) provided in the first housing 24.
The inverter assembly 100 converts DC power supplied from the outside into multiphase AC power and supplies it to the electric motor 26, and controls the rotation speed of the electric motor 26.

Further, a cover 150 is attached to the first housing 24 so as to cover the inverter assembly 100, and the cover 150 isolates the inverter housing chamber 101 from the outside. Here, the cover 150 constitutes an outer wall of the electric compressor 10. That is, the cover 150, the first housing 24, and the second housing 25 isolate the interior of the electric compressor 10 from the outside. Further, the inverter accommodating chamber 101 is formed with the cover 150 and the first housing 24 as outer walls.
In addition, when the electric compressor 10 is used, it arrange | positions so that the direction which looked at the inverter assembly 100 from the drive shaft 22 in FIG. That is, the inverter assembly 100 is disposed above the first housing 24.

  The end of the drive shaft 22 on the drive crank mechanism 19 side is supported by the shaft support member 15 via a ball bearing 22e, and the rear end is supported by the shaft support portion 24h of the first housing 24 via a ball bearing 22f. The A seal 22g is provided on the rear side of the ball bearing 22e, and seals between the drive shaft 22 and the shaft support member 15.

A fluid, which is a refrigerant, flows through the space covered by the first housing 24 and the second housing 25 described above. In this space, the portion defined by the first housing 24 and the shaft support member 15 is the motor chamber 27, and the portion defined by the first housing 24, the second housing 25, and the shaft support member 15 is the crank. Chamber 21. The motor chamber 27 and the crank chamber 21 communicate with each other through a passage (not shown).
Here, as shown in FIGS. 1 and 2, the motor chamber 27 and the inverter accommodating chamber 101 are adjacent to each other with the first housing 24 interposed therebetween.

  A discharge chamber 32 defined by the fixed scroll 11 and the second housing 25 is provided on the side opposite to the compression chamber 13 with respect to the discharge port 47, and the refrigerant compressed in the compression chamber 13 passes through the discharge port 47 to the discharge chamber 32. Is discharged. The discharge chamber 32 is provided with a reed valve 34 and a retainer 36 to prevent the reverse flow of the refrigerant, that is, the flow from the discharge chamber 32 toward the discharge port 47. The discharge chamber 32 has an external opening 32a that communicates with the outside. The inside and the outside of the electric compressor 10 communicate with each other through the external opening 32a.

  In the electric compressor 10 configured as described above, the refrigerant flows into the motor chamber 27 from the outside through a suction port (not shown). Further, the refrigerant flows from the motor chamber 27 into the compression chamber 13 that communicates with the crank chamber 21 and the crank chamber via a suction passage (not shown). In the compression chamber 13, the refrigerant is compressed by the turning of the orbiting scroll 12 accompanying the rotation of the drive shaft 22, flows into the discharge chamber 32 from the discharge port 47, and is further discharged to the outside through the external opening 32a. .

FIG. 2 shows an inverter assembly 100 according to Embodiment 1 of the present invention and the configuration around it.
2 is a partial cross-sectional view taken along line II-II in FIG.
The cover 150 and the first housing 24 sandwich the gasket 120, thereby isolating the inverter accommodating chamber 101 from the outside. The gasket 120 is a plate-like member composed of a core that is an iron plate and a rubber material that surrounds the core.

The inverter assembly 100 includes a substrate 112 having an electric circuit, and a heat transfer plate 110 as a base that supports the substrate 112. The heat transfer plate 110 is made of a material having a relatively high thermal conductivity, such as aluminum, and mediates heat conduction between the motor chamber 27 and the inverter housing chamber 101. The substrate 112 is fixed to the heat transfer plate 110 with screws 128.
The cover 150, the heat transfer plate 110, and the first housing 24 are fastened together by screws 118, and the heat transfer plate 110 is attached in close contact with the first housing 24. Since the screw 118 is provided at a position different from the cross section of FIG. 2, the portion to be fastened together does not appear in FIG. FIG. 2 shows only the screw head of the screw 118 for explanation.
Further, the inverter assembly 100 includes a capacitor 114, a coil 116, an airtight terminal 122, IGBTs (insulated gate bipolar transistors) 124 and 125, and varistors (not shown) as electronic components. Including.

  Capacitor 114 is an electrolytic capacitor, for example, and has leads 114a. The leads 114a are soldered to the substrate 112 to electrically connect the capacitor 114 to the electric circuit of the substrate 112. Capacitor 114 is fixed to substrate 112 with lead 114a and solder (not shown) around lead 114a, and is also fixed to heat transfer plate 110 with resin adhesive 114b.

  The coil 116 has a lead 116 a, and the lead 116 a is soldered to the substrate 112 to electrically connect the coil 116 to an electric circuit of the substrate 112. The coil 116 is fixed to the substrate 112 with a lead 116a and solder around the lead 116a (not shown), and the coil 116 is fixed to the heat transfer plate 110 with a resin adhesive 116b.

The IGBTs 124 and 125 have leads 124a and 125a, respectively, which are soldered to the substrate 112 to electrically connect the IGBTs 124 and 125 to the electrical circuit of the substrate 112. IGBTs 124 and 125 are fixed to heat transfer plate 110 by screws 126 and 127, respectively.
The hermetic terminal 122 has a lead 122 a, and the lead 122 a is soldered to the substrate 112 to electrically connect the hermetic terminal 122 to an electric circuit of the substrate 112. The airtight terminal 122 is fixed to the heat transfer plate 110. Although not shown, the hermetic terminal 122 electrically connects the inverter assembly 100 and the electric motor 26 (see FIG. 1) in the first housing 24, and accommodates the inverter accommodating chamber 101 and the electric motor 26. The motor chamber 27 which is a space to be formed is hermetically isolated.

  In this way, the substrate 112, the capacitor 114, and the coil 116 are supported by the heat transfer plate 110, and the inverter assembly 100 is assembled. As described above, the heat transfer plate 110 is fixed to the first housing 24 by the screws 118, and thereby the inverter assembly 100 is fixed to the first housing 24. This fixing is a detachable screwing with a screw 118.

A refrigerant passage including at least a part of the motor chamber 27 is formed between the first housing 24 and the stator 30 (see FIG. 1), and the refrigerant flows therethrough. This refrigerant cools the heat transfer plate 110 through the first housing 24, thereby cooling the inverter assembly 100. Further, the refrigerant cools the electric motor 26 via the stator 30.
The refrigerant passage is a passage on the low pressure side of the electric compressor 10. That is, the motor chamber 27 is provided in the suction pressure region of the electric compressor 10.

In the first housing 24, a cooling hole 130 is formed immediately below the IGBT 125 from the motor chamber 27 toward the inverter accommodating chamber 101. The cooling hole 130 is a through-hole penetrating the first housing 24, and its upper end opening 130a is in contact with the heat transfer plate 110, whereby the heat transfer plate 110 is in contact with the refrigerant in the suction pressure region. The shape of the cooling hole 130 is, for example, a hollow cylindrical shape, but this may be another shape.
A sealing structure for sealing the motor chamber 27 and the inverter accommodating chamber 101 is provided around the cooling hole 130. In the example of FIG. 2, an O-ring groove 130b is provided around the upper end opening 130a of the cooling hole 130, and an O-ring 130c is disposed therein as a seal member. The O-ring 130 c is sandwiched between the first housing 24 and the heat transfer plate 110 and isolates the motor chamber 27 and the inverter housing chamber 101 around the cooling hole 130.

When assembling the electric compressor 10, the inverter assembly 100 is first assembled as a unit. This may be done in any order. For example, each electronic component is first attached to the heat transfer plate 110, and then the substrate 112 is fixed to the heat transfer plate 110 with screws 128, and each electronic component is attached to the substrate 112. Connected to.
After the inverter assembly 100 is assembled, it is incorporated into the electric compressor 10. This is performed by fixing the cover 150, the heat transfer plate 110, and the first housing 24 together by screws 118.
Here, since the gel is not sealed in the inverter accommodating chamber 101 as described above, the heat transfer plate 110 is released from the first housing 24 by removing the screw 118, and the inverter assembly 100 can be removed. it can. That is, the integrated inverter assembly 100 is a cartridge type and is configured to be detachable from the electric compressor 10.

  According to the electric compressor 10 configured as described above, the refrigerant in the suction pressure region of the electric compressor 10, that is, the low-temperature side refrigerant, contacts the heat transfer plate 110 from the motor chamber 27 through the cooling hole 130 at its upper end 130a. As a result, the heat transfer plate 110 is directly cooled around the cooling hole 130. Here, since the cooling hole 130 is formed immediately below the IGBT 125, the refrigerant in the cooling hole 130 efficiently cools the IGBT 125 via the heat transfer plate 110. Thus, electric compressor 10 can improve the cooling performance of IGBT 125 and inverter assembly 100 including the same.

Moreover, since the IGBT 125 can be maintained at a lower temperature by improving the cooling efficiency, the heat-resistant temperature required for the IGBT 125 can be further lowered. Thereby, a smaller or lower-cost switching element can be employed.
Furthermore, since temperature protection is not required even when a switching element having a low heat resistance temperature is used, the inverter assembly 100 can be used in a wider operating range, that is, in more various operating states.
Further, since the refrigerant directly cools the heat transfer plate 110 without passing through the first housing 24, the cooling efficiency can be improved as compared with the configuration in which the refrigerant is indirectly cooled through the first housing 24. .

  Moreover, in the electric compressor 10, since the gel is not enclosed in the inverter accommodating chamber 101 and the inverter assembly 100 can be detached, the maintenance can be performed as compared with the conventional configuration in which the inverter assembly is fixed so as not to be removed. It becomes easy. Thus, the cooling efficiency can be improved as described above while facilitating maintenance.

  In some conventional configurations, fins or the like are formed to cool the inverter. However, in such a configuration, the shape of the mold for forming the fins or the like is complicated, and the maintenance of the mold is difficult. In the electric compressor 10 according to the present embodiment, since the cooling hole 130 can be formed by forming a through hole in the first housing 24, a mold having a relatively simple shape can be used, and maintenance is easier. Become.

In the above-described first embodiment, in the example of FIG. 2, the position of the cooling hole 130 is directly below the IGBT 125, but it may not be directly below, for example, below or in the vicinity of the IGBT 125. Furthermore, it may be provided anywhere as long as the efficiency of cooling the IGBT 125 is improved.
The cooling hole 130 may not cool the IGBT 125, or may cool at least one of the electronic components, for example, the capacitor 114 or the coil 116. In this case, the cooling hole 130 may be provided directly below, in the vicinity of the capacitor 114 or the coil 116, or at a position where the efficiency of cooling them is improved. In such a configuration, similarly to the configuration shown in FIG. 2, the inverter assembly 100 including electronic components can be efficiently cooled.

In the example of FIG. 2, only one cooling hole 130 is provided for the IGBT 125, but the cooling hole 130 may be provided for a plurality of elements. For example, one cooling hole may be provided for each of IGBTs 124 and 125, and one cooling hole may be provided for each of the other electronic components.
A plurality of cooling holes 130 may be provided for one electronic component.

  Although the electric compressor 10 is exemplified as a scroll type, it may be of other types as long as it has a compression mechanism for compressing fluid.

It is a figure which shows the structure of the electric compressor which concerns on Embodiment 1 of this invention. It is a figure which shows the structure of the inverter assembly contained in the electric compressor of FIG. 1, and its periphery.

Explanation of symbols

  24 First housing (housing), 26 Electric motor, 100 Inverter assembly, 101 Inverter housing chamber, 110 Heat transfer plate (base), 112 Substrate, 114 Capacitor (electronic component), 116 Coil (electronic component), 124 and 125 IGBT (Electronic component, switching element), 130 cooling hole (through hole), 130a upper end opening (one end of the through hole), 130c O-ring.

Claims (3)

A compression mechanism for sucking fluid from the suction pressure region;
An electric motor for driving the compression mechanism;
A motor chamber provided in the suction pressure region and containing the electric motor;
An inverter assembly that converts DC power into multi-phase AC power and supplies it to the electric motor, and controls the rotational speed of the electric motor;
An inverter storage chamber for storing the inverter assembly;
The inverter assembly includes a board having an electric circuit, an electronic component connected to the board, and a base that supports the board, and is detachably fixed in the inverter housing chamber.
In the electric compressor adjacent to the motor chamber and the inverter accommodating chamber with a housing interposed therebetween,
A through hole is formed in the housing from the motor chamber toward the inverter accommodating chamber.
One end of the through hole is in contact with the base,
The electric compressor, wherein the motor storage chamber and the inverter storage chamber are sealed around the through hole.   The electric compressor according to claim 1, wherein the seal between the motor storage chamber and the inverter storage chamber is made using an O-ring.   The electric compressor according to claim 1, wherein the electronic component includes a switching element, and the through hole is provided in the vicinity of the switching element.

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