Patent Application
20100209266
The present invention relates to an electric compressor integral with a drive circuit, in which the drive circuit for driving a motor is incorporated, and relates to an electric compressor integral with a drive circuit in which heat generating components can be effectively cooled.
As to an electric compressor integral with a drive circuit in which the drive circuit for driving a motor is incorporated, many kinds of structures where sucked refrigerant gas is utilized for cooling the drive circuit having heat generating components are known, as disclosed in Patent documents 1-3.
Patent document 1: JP-2000-291557-A
Patent document 2: JP-2002-174178-A
Patent document 3: JP-2001-263243-A
However, a conventional cooling structure utilizing sucked refrigerant gas has not always been a structure where the drive circuit can be effectively cooled over a wide range, or a structure where a part to be desired to enhance the cooling can be effectively cooled. In addition, also known is a structure where the refrigerant gas which cooled the drive circuit of the motor is sucked through the motor mounted section into a compression mechanism section so as to cool the motor, however, this is not a structure where the motor can be effectively cooled over a wide range, or a structure where a lubrication in a motor bearing can be kept well during the cooling.
Therefore the object of the present invention is to provide a structure where a heat generating component, specifically a heat generating component in a drive circuit, can be easily cooled effectively, and where motor cooling and bearing lubrication can be easily kept well at a side of a motor installation section.
To achieve the above-described object, an electric compressor integral with a drive circuit is an electric compressor integral with a drive circuit, in which a compression mechanism section and a motor for driving the compression mechanism section are contained, and into which the drive circuit for driving the motor is incorporated, characterized in that a refrigerant gas chamber having a refrigerant gas expansion space, into which refrigerant gas is introduced, is formed between an installation section of the drive circuit and an installation section of the motor by a first partition wall provided on a side of the installation section of the drive circuit and a second partition wall provided on a side opposite the drive circuit installation section side, which is a side of the installation section of the motor, wherein the refrigerant gas chamber is interrupted by the first partition wall against the installation section of the drive circuit, and is communicated with the installation section of the motor by a through hole, provided in the second partition wall, through which the refrigerant gas can pass.
In this electric compressor integral with a drive circuit, because the refrigerant gas chamber having the refrigerant gas expansion space into which refrigerant gas is introduced is formed between the installation section of the drive circuit and the installation section of the motor, the introduced refrigerant gas flows in the refrigerant gas chamber and is once trapped in the refrigerant gas chamber in a well expanded condition. Therefore, comparatively large cooling capacity for the part to be cooled can be given to the refrigerant gas in the refrigerant gas chamber, so that the part to be cooled can be cooled by the refrigerant gas more effectively. In addition, because the refrigerant gas chamber is formed by the first partition wall provided on the side of the installation section of the drive circuit and the second partition wall provided on its opposite side, which is the side of the installation section of the motor, an optimum structure for cooling the drive circuit can be employed for the first partition wall, and independently, an optimum structure for lubricating the bearing section can be employed for the second partition wall, so that target structures can be achieved more easily and more surely.
In the electric compressor integral with a drive circuit according to the present invention, it is possible that a compressor housing containing the compression mechanism section and the motor, and a drive circuit housing incorporating the drive circuit are separately composed, the first partition wall is provided in the drive circuit housing, and the refrigerant gas chamber is formed by assembling the drive circuit housing on the compressor housing. In this structure, a desirably designed refrigerant gas chamber can be easily formed if only the drive circuit housing is assembled on the compressor housing. In addition, because the compressor housing and the drive circuit housing are composed in different bodies, a shell diameter at the compressor housing side can be made larger than a shell diameter at the drive circuit housing, so that cooling surface area at the first partition wall side is ensured to be wide, and specifically, the cooling performance at the drive circuit side can be developed. In order to seal a gap between the compressor housing and the drive circuit housing which are assembled each other, a gasket or O-ring can be used, which is superior in a sealing performance and is inexpensive and long-lived.
Alternatively, it is possible that a compressor housing containing the compression mechanism section and the motor, and a drive circuit housing containing the drive circuit are composed as an integrated housing, and the refrigerant gas chamber is formed by inserting a member forming the first partition wall to be fixed into the integrated housing. In this structure, because housings are integrated, the housing itself can be easily manufactured, and a desirably designed refrigerant gas chamber can be easily formed by inserting the member different from the integrated housing forming the first partition wall to be fixed into the integrated housing.
In addition, in the electric compressor integral with a drive circuit according to the present invention, it is preferred that the through hole is provided on the second partition wall, at a position corresponding to an installation section of a sealed terminal for supplying an electricity to the motor, sealed terminal extending through the first partition wall from the drive circuit. When thus constructed, at least some of the refrigerant gas introduced thereinto is sent to the motor side through the through hole of the second partition wall after led to the sealed terminal installation section surely, so that the sealed terminal section which is required to be cooled can be cooled more surely. In addition, when most of the refrigerant gas is flowed near the sealed terminal, the cooling can be focused on the sealed terminal section and its cooling performance can be increased.
Further, it is preferred that plural through holes are provided, so that the refrigerant gas can be delivered more surely over a wide range, specifically for the motor side.
As plural through-holes, it is preferred that a through hole with a relatively larger cross section and a through hole with a relatively smaller cross section are provided. Thereby the distribution amount can be set optimum when the refrigerant gas is sent to the motor side through the second partition wall.
The sealed terminal section can be cooled more strongly, specifically when formed as the through hole with a relatively larger cross section is a through hole which is provided on the second partition wall at a position corresponding to an installation section of a sealed terminal for supplying an electricity to the motor, the sealed terminal extending through the first partition wall from the drive circuit.
Further, because the sucked refrigerant gas usually includes lubricating oil, the refrigerant gas which is sent to the motor side through the through hole on the second partition wall can be used for the lubrication. Specifically, when a through hole which communicates from the refrigerant gas chamber to a bearing section for a rotational shaft of the motor is provided on the second partition wall, the bearing section for the rotational shaft of the motor can be lubricated more adequately. By this lubricant securement, it can be expected that an abnormal noise generation from the bearing section is prevented and that a lifetime of the bearing improved.
Further, preferable is a structure where a concavo-convex structure is formed on a surface forming the refrigerant gas chamber of the first partition wall. The concavo-convex structure can increase an area, in other words a surface area of the first partition wall in the refrigerant gas chamber to cool the drive circuit side, where the heat is radiated from the drive circuit and by just that much, the cooling effect can be improved.
It is preferred that the concavo-convex structure on the surface forming the refrigerant gas chamber of the first partition wall is such as formed as a rib structure for the first partition wall. Such a rib structure can be provided integrally with the first partition wall. Formed as a rib structure, the performance of heat exchange with refrigerant gas in the refrigerant gas chamber can be improved by the surface area increase, and the first partition wall strength can be improved. Specifically when the rib structure is composed of ribs which extend like a lattice, the strength and the heat exchange performance can be further improved.
Also it is preferred that a protrusion which obstructs a flow of the refrigerant gas in the refrigerant gas chamber is provided on a surface forming the refrigerant gas chamber of the second partition wall. Such a protrusion can be formed integrally with the second partition wall.
By providing such a protrusion, refrigerant gas flows in a whirl near the protrusion in the refrigerant gas chamber, so that the detention time of the refrigerant gas becomes long because the refrigerant gas flows in a longer route. That can promote the heat exchange with components, such as a power semiconductor element, which are provided on the opposite side of the refrigerant gas chamber of the first partition wall, so that the cooling can be performed more effectively. In addition, because the amount of refrigerant gas flowing near the partition wall surface in the refrigerant gas chamber increases, further promotion of the heat exchange can be expected. Further, because the cooling of the second partition wall is further promoted for the same reason, the cooling of the bearing section of the rotational shaft of the motor provided at the opposite side of the refrigerant gas chamber relative to the second partition wall can be also promoted, so that the lifetime extension of the bearing can be expected. It is preferred that such plural protrusions are disposed. By disposing plurally, the above-described increased effect of cooling performance can be expected over a wide range in the refrigerant gas chamber.
The drive circuit usually comprises an inverter circuit having a power semiconductor element, and power circuit components such as a smoothing capacitor and a noise filter which are disposed in an electricity supply section to the inverter circuit. It is preferred that the power circuit components are disposed in a region which is partitioned relatively to the inverter circuit by a partition wall. Although such power circuit components are relatively larger so that the amount of heat generation may become greater as a whole, these components can be effectively cooled from the periphery by disposing these components in another region partitioned by the partition wall.
In addition, it is possible that the first partition wall has a region which protrudes into said refrigerant gas chamber and the power circuit components are disposed on a surface of this protruded region positioned at a side opposite to the refrigerant gas chamber. By employing this structure, at least some of these relatively larger sized components can be set in the above-described region, thereby the contact area between these components and the first partition wall can be increased and the cooling effect by the refrigerant gas chamber can be increased. Further, the axial directional size of the compressor can be shortened, so that a whole compressor can be reduced in size and weight.
Furthermore, a refrigerant gas guide plate can be provided in the refrigerant gas chamber. When the refrigerant gas guide plate is provided, refrigerant gas in the refrigerant gas chamber can be led to a desirable course and a desirable part more surely and the cooling can be performed more efficiently.
Specifically by forming the refrigerant gas guide plate into a shape which guides refrigerant gas introduced into the refrigerant gas chamber to a side of the second partition wall after guiding the refrigerant gas along the first partition wall, it is possible that the drive circuit side is cooled adequately over a wide range and that the refrigerant gas is led to the sealed terminal section more surely, so that the cooling effect can be increased as a whole.
The refrigerant gas is introduced into the refrigerant gas chamber through a suction port, which can be formed either on a drive circuit housing containing the drive circuit or on a compressor housing containing the compression mechanism section and the motor. The location to form the suction port can be determined by considering the peripheral space of the compressor assembled in a vehicle, or the avoidance of the interference with other components.
It is preferable in designing and manufacturing that the second partition wall is formed integrally with a compressor housing containing the compression mechanism section and the motor. However, it is possible that the second partition wall which has been formed separately is firmly fixed to the compressor housing.
The first partition wall can be formed integrally with a drive circuit housing containing the drive circuit. However, when the compressor housing and the drive circuit housing are composed as an integrated housing as described above, it is preferred in assembling, specifically in assembling the drive circuit in the compressor, that a first partition wall forming member which is formed as a body which is separated from the integrated housing is inserted to be fixed thereto.
As to a disposition structure inside the compressor, the installation section of the motor, the refrigerant gas chamber and the installation section of the drive circuit may be disposed in this order in a compressor axial direction, and alternatively, the installation section of the motor, the refrigerant gas chamber and the installation section of the drive circuit may be disposed in this order in a compressor radial direction. The structure to be selected therebetween can be determined according to a situation of surroundings where the compressor is mounted.
Thus, in the electric compressor integral with a drive circuit according to the present invention, because the refrigerant gas chamber having the refrigerant gas expansion space into which refrigerant gas is introduced is formed between the installation section of the drive circuit and the installation section of the motor, the drive circuit side can be easily cooled effectively, and for the motor side, cooling the motor and lubricating the bearing section can be easily kept better.
Further, a desirably designed refrigerant gas chamber can be easily formed if the compressor housing and the drive circuit housing are separately composed and are assembled to form the refrigerant gas chamber. Also in a case where both housings are composed as an integrated housing, the housing itself can be easily manufactured, and a desirably designed refrigerant gas chamber can be easily formed by inserting the member different from the integrated housing forming the first partition wall to be fixed thereinto.
Further, more adequate cooling structure can be achieved by accordingly devising: the position and the number of the through hole of the second partition wall; the first partition wall structure at the refrigerant gas chamber side or at the drive circuit side; the structure where the guide plate is provided in the refrigerant gas chamber; and the structure of the suction port through which refrigerant gas is led into the refrigerant gas chamber, etc.
Hereinafter, desirable embodiments will be explained referring to figures.
In
Drive circuit 5 comprises: inverter circuit 20 with substrate 18 which is fixed on an surface of the first partition wall to be described by insulation member 17 and power semiconductor element 19 which is disposed thereon; power circuit components, such as smoothing capacitor 21 and noise filter 22, which are disposed in the power dispatching section to inverter circuit 20. It is explained as referring to a circuit diagram in
Refrigerant gas chamber 42 formed by an expansion space of refrigerant gas into which refrigerant gas is introduced through first partition wall 40 provided on a side of the installation section of drive circuit 5 and second partition wall 41 provided on an opposite side thereof, which is a side of the installation section of motor 3. In this embodiment, first partition wall 40 is formed integrally with drive circuit housing 6 and second partition wall 41 is formed integrally with compressor housing 4. Refrigerant gas 44 is sucked from refrigerant gas suction port 43 provided in drive circuit housing 6 and is introduced into refrigerant gas chamber 42, and is once expanded in refrigerant gas chamber 42 in flowing in refrigerant gas chamber 42. Refrigerant gas chamber 42 is interrupted by first partition wall 40 against an installation section of drive circuit 5, and is communicated with an installation section of motor 3 by through holes 45,46,47 provided in second partition wall 41, through which refrigerant gas 44 can pass. Among these through holes, through hole 45 is provided at a position corresponding to an installation section of sealed terminal 28 which extends as penetrating through first partition wall 40, and through hole 46 is provided on second partition wall 41, at a position on a side opposite to through hole 45. Through hole 47 is formed as communicating with a section of bearing 15 of motor rotational shaft 9 in this embodiment. In addition, through hole 45 provided at a position corresponding to an installation section of sealed terminal 28 is formed as a through hole whose cross sectional area is larger than that of the other through holes 46,47. Further, in this embodiment concavo-convex section 48 with a concavo-convex structure is provided on a forming surface of refrigerant gas chamber 42 of first partition wall 40, so that a cooling surface area in this part is increased. Furthermore, in this embodiment partition wall 49 is provided between inverter circuit 20 in a part of drive circuit 5 and components, such as smoothing capacitor 21 and noise filter 22 but inverter circuit 20, so that smoothing capacitor 21 and noise filter 22 are disposed in a region sectioned by partition wall 49 against inverter circuit 20.
Thus constructed electric compressor integral with drive circuit 100 has a structure where an installation section of motor 3, refrigerant gas chamber 42 and an installation section of drive circuit 5 are disposed in this order in the compressor axial direction. Refrigerant gas 44 sucked through refrigerant gas suction port 43 is introduced into refrigerant gas chamber 42 having a comparatively larger volume, and drive circuit 5 is efficiently cooled through first partition wall 40 by refrigerant gas 44 flowing in refrigerant gas chamber 42. Motor 3 side is cooled by refrigerant gas 44 sucked via through hole 45,46,47 on second partition wall from the inside of refrigerant gas chamber 42, and refrigerant gas 44 which has been utilized for cooling is compressed by compression mechanism section 2 and discharged out of the compressor through discharge port 16. Because drive circuit housing 6 containing drive circuit 5 is composed separately from compressor housing 4, if only drive circuit housing 6 with first partition wall 40 is assembled with compressor housing 4, refrigerant gas chamber 42 can be easily formed into a desirable shape. By forming refrigerant gas chamber 42 with the desirable shape, drive circuit 5 can be surely cooled effectively. In addition, when both housing 4,6 are separately composed, only drive circuit housing 6 is formed as having a larger diameter relatively to compressor housing 4 which mainly determines a shell diameter of the compressor, so that the cooling area at the side of first partition wall 44 can be increased. Therefore drive circuit 5 can be cooled effectively while whole compressor 100 is miniaturized.
In addition, because the cross section of through hole 45 provided at a position corresponding to the installation section of sealed terminal 28 is set larger than the other through holes 46,47, most of refrigerant gas can be introduced into an installation section of sealed terminal 28 and then, can be delivered to motor 3 side. Thereby a part of sealed terminal 28 which generates heat and is required to be cooled more efficiently can be surely cooled efficiently.
In addition, because concavo-convex section 48 is provided on a forming surface of refrigerant gas chamber of first partition wall 40 so as to extend a surface area for heat exchange between refrigerant gas chamber 42 and first partition wall 40, drive circuit 5 can be cooled efficiently over a wide area through first partition wall 40.
Further, because smoothing capacitor 21 and noise filter 22 are disposed in a region which is partitioned by partition wall 49 against a power element circuit, smoothing capacitor 21 and noise filter which have relatively greater thermal capacities can be cooled from a whole periphery, so that even these components other than the power element circuit can be cooled efficiently.
Furthermore, because refrigerant gas including lubricating oil is introduced into a part of bearing 15 of motor rotational shaft 9 via through hole 47, the lubrication is ensured in a good condition as well as the cooling of this part, so that abnormal noise generation can be prevented and lifetime extension of bearing 15 can be expected.
In each embodiment, although the compressor housing and the drive circuit housing are separately provided and assembled to form the refrigerant gas chamber, alternatively both housings can be composed integrally in the present invention.
The structure of an electric compressor integral with a drive circuit according to the present invention is applicable to an electric compressor incorporating only a motor as a drive source as well as so-called hybrid compressor which incorporates a first compression mechanism driven by an external drive source and a second compression mechanism which can be driven independently from the first compression mechanism by an onboard motor. Specifically it is preferably used as an electric compressor used for vehicles.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2007-246772 | Sep 2007 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2008/065279 | 8/27/2008 | WO | 00 | 3/25/2010 |
