EP4476443A1

EP4476443A1 - A motor driven compressor

Info

Publication number: EP4476443A1
Application number: EP22907568.4A
Authority: EP
Inventors: Hariharan BANUMURTHY; Herve Ribot; Praveen Mathesan; Prakash GANESAN; Antony Vinoth RAJA
Original assignee: Valeo Japan Co Ltd
Current assignee: Valeo Electrification SAS
Priority date: 2021-12-15
Filing date: 2022-12-21
Publication date: 2024-12-18
Also published as: CN118401754A; EP4476443A4; WO2023113046A1

Abstract

A motor driven compressor (100) includes a compression unit (110) and an electric motor (120) both received in a main housing (110a) and an inverter unit (130) received in an inverter housing (140). The compression unit (110) compresses a refrigerant fluid. The electric motor (120) drives the compression unit (110). The inverter unit (130) includes a PCB (200) configured with a plurality of electronic components (210) mounted thereon and controls the electric motor (120). The inverter housing (140) includes an end wall 140a, a peripheral wall (140b) and a cover (140c) defining an interior space that receives, positions and holds the PCB (200) therein. The spaced apart portions of the PCB (200) are fixed to the inverter housing (140) by fixing means. At least one of the unfixed portions of the PCB (200) is glued to elements adjacent thereto to prevent vibration of the PCB.

Description

A MOTOR DRIVEN COMPRESSOR

The present invention relates to a motor driven compressor, particularly, the present invention relates to a motor driven compressor used in vehicle air conditioning system.

Generally, a motor-driven compressor for an air-conditioning system of a vehicle includes a compression unit for compressing refrigerant, an electric motor to drive the compression unit and an inverter unit. The motor driven compressor further includes a main housing to accommodate the compression unit and the electric motor and a separate inverter housing to accommodate the inverter.

The inverter is configured with a Printed Circuit Board (PCB). The inverter housing includes an end wall, a peripheral wall extending from the periphery of the end wall to define a PCB accommodation space and an open end of the inverter housing closed by a cover received inside the inverter housing. The Printed Circuit Board is functionally coupled to the electric motor received in the main housing and drives the electric motor in a controlled manner. Specifically, the PCB accommodation space is disposed adjacent to the electric motor receiving portion of the main housing, when the inverter housing is assembled to the main housing. The PCB includes a plurality of electronic components mounted thereon for performing inverter operation and controlling motor in various aspects by giving controlled input to the electric motor.

The cover protects the PCB positioned in the PCB accommodation space from external shocks and external environmental conditions such as dust, moisture etc. that can be detrimental to the PCB and other electronic components held in the inverter housing. The inverter housing and the cover are of a metallic material for providing sufficient stiffness to the structure thereof and prevent transmission of electromagnetic noise therethrough.

The inverter housing further includes a separator element. The separator element is of insulating material and separates the electronic components mounted on the PCB. In some cases, the separator element also positions the PCB inside the inverter housing. At least one of the PCB and the separator is supported and fixed on the screw hubs formed on the inverter housing, wherein the holes in the respective screw hubs receive screws received inside the housing and passing through the PCB and the separator. More specifically, the PCB and the separator are mounted inside the housing by means of screws passing there through, while some portions of the PCB remain unfixed. More specifically, space constraints associated with forming the screw hubs within the inverter housing, creepage constraints and other factors such as the PCB subjected to strains due to mounting screws being disposed close to each other are responsible for some portions of the PCB remaining unfixed. Accordingly, at least some sections of the PCB is not sufficiently supported and remain unfixed. Particularly, the peripheral portion of the PCB overhangs and remain unfixed. The unfixed portion, particularly, the overhanging portions of the PCB and the separator are subjected to vibrations and cause noise issues. The problems associated with vibration of the unfixed portions of the PCB are more severe, relevant and frequent when the PCBs are used in automotive environment, wherein the PCB is prone to be subjected to vibrations due to vehicle traversing over rough terrain. None of the prior art proposes any solution to address the vibration, noise and reliability issues caused by portions of the PCB remaining unfixed.

Accordingly, there is a need for a motor driven compressor, wherein the PCB disposed inside an inverter housing is securely held and fixed to prevent undesirable movement thereof. Further, there is a need of a motor driven compressor, wherein the PCB disposed inside an inverter housing is securely held and fixed to prevent vibration of any portion thereof, thereby preventing the problems such as noise arising due to vibration thereof. Furthermore, there is a need of a motor driven compressor, wherein the PCB of the compressor is stably supported and fixed to avoid vibration, accordingly, the PCB and the compressor is reliable and exhibits extended service life.

OBJECTS

An object of the present invention is to provide a motor driven compressor that obviates the drawbacks associated conventional motor driven compressor in which portions of elements thereof such as PCB are subjected to vibration because of being unfixed or loosely held, thereby causing noise.
Another object of the present invention is to provide a motor driven compressor that requires comparatively less maintenance compared to conventional motor driven compressor.
Yet another object of the present invention is to provide a motor driven compressor that is comparatively silent in operation compared to conventional motor driven compressor.
Still another object of the present invention is to provide a motor driven compressor that is comparatively more reliable and exhibits extended service life compared to conventional motor driven compressor.
Yet another object of the present invention is to provide a motor driven compressor that is configured with simple arrangement for preventing vibration of unfixed portions of the PCB and other similar planar elements.
In the present description, some elements or parameters may be indexed, such as a first element and a second element. In this case, unless stated otherwise, this indexation is only meant to differentiate and name elements which are similar but not identical. No idea of priority should be inferred from such indexation, as these terms may be switched without betraying the invention. Additionally, this indexation does not imply any order in mounting or use of the elements of the invention.

A motor driven compressor is disclosed in accordance with an embodiment of the present invention. The motor driven compressor includes a compression unit and an electric motor both received in a main housing and an inverter unit received in an inverter housing. The compression unit compresses a refrigerant fluid. The electric motor drives the compression unit. The inverter includes a Printed Circuit Board configured with a plurality of electronic components mounted thereon. The Printed Circuit Board controls the electric motor. The inverter housing includes an end wall, a peripheral wall and a cover defining an interior space that receives, positions and holds the Printed Circuit Board therein. The Printed Circuit Board is fixed to the inverter housing by fixing spaced-apart portions of the Printed Circuit Board to the inverter housing by means of fixing means, while the remaining portions of Printed Circuit Board remain unfixed. At least one of the unfixed portions of the Printed Circuit Board is glued to elements adjacent thereto to prevent vibration of the Printed Circuit Board.

Specifically, at least a portion of a periphery of the Printed Circuit Board is disposed between the peripheral wall of the inverter housing and the cover.

More specifically, at least one of the peripheral wall and the cover is formed with a cutout that forms a cavity to receive at least a portion of the periphery of the Printed Circuit Board and glue to form glue connection with at least one side of the Printed Circuit Board.

Preferably, the peripheral wall and the cover are formed with respective first and second cutouts aligned to each other to form a cavity that receives at least a portion of a periphery of the Printed Circuit Board and glue to form glue connection with both sides of the Printed Circuit Board.

In accordance with another embodiment of the present invention, at least one of the unfixed portions of the Printed Circuit Board is supported over and secured to a separator element received, positioned and held within the inverter housing. At least one of the unfixed portions of the separator element is glued to elements adjacent thereto to prevent vibration of the separator element.

Further, at least one of the Printed Circuit Board and a separator element is supported over, fixed and glued to at least one screw hub extending from the end wall towards the cover. The screw hub receives the fixing means in the form of a mounting screw for fixing at least one of the Printed Circuit Board and the separator element to the end wall.

Generally, at least a portion of a periphery of the Printed Circuit Board is glued to at least one of the separator element and the inverter housing.

In accordance with another embodiment of the present invention, at least a portion of a periphery of the separator element is glued to the inverter housing.

Specifically, at least a portion of a periphery of the separator element is disposed between the peripheral wall and the cover.

More specifically, at least one of the peripheral wall and the cover is formed with a cutout that forms a cavity to receive at least a portion of a periphery of the separator element and glue to form glue connection with at least one side of the separator element.

Preferably, the peripheral wall and the cover are formed with respective first and second cutouts aligned to each other to form a cavity that receives at least a portion of a periphery of the separator element and glue to form glue connection with both sides of the separator element.

In accordance with yet another embodiment of the present invention, at least a portion of a periphery of the Printed Circuit Board and the separator element is disposed between the peripheral wall and the cover.

Preferably, the peripheral wall and the cover is formed with respective first and second cutouts aligned to each other to form a cavity to receive glue and at least a portion of a periphery of the Printed Circuit Board and the separator element to form glue connection between the Printed Circuit Board and the cover on one side and between the separator element and the peripheral wall on the other side.

Generally, the unfixed portion of the Printed Circuit Board is glued to at least one of the inverter housing and the separator element.

Further, the unfixed portion of the separator element is glued to the inverter housing.

Furthermore, a portion of cured glue forms sealing connection between the between the cover and the peripheral wall of the inverter housing.

In accordance with another embodiment of the present invention the inverter housing is formed with at least one raised platform extending from end wall towards the cover and provides support to and forms glue connection with the unfixed portion of at least one of the Printed Circuit Board and separator element.

Generally, the glue is silicon based epoxy resin.

In accordance with still another embodiment of the present invention, the PCB and the separator element includes different sized holes aligned to each other that receives different sections of the screw hub of different dimensions and are secured to the different sections of the screw hubs by means of glue connection.

Other characteristics, details and advantages of the invention can be inferred from the description of the invention hereunder. A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying figures, wherein:

illustrates a schematic representation of a motor-driven compressor for an air-conditioning system in accordance with an embodiment of the present invention; illustrates a schematic cross sectional representation of the inverter unit in accordance with an embodiment of the present invention received inside an inverter housing, wherein a peripheral portion of a PCB of the inverter unit is glued to the inverter housing in accordance with an embodiment of the present invention, also is illustrated an enlarged view depicting the glued connection; illustrates an enlarged view depicting a portion of the cured glue forming connection between the PCB and the inverter housing; illustrates an isometric view of an inverter unit of the motor-driven compressor in accordance with another embodiment of the present invention that includes a separator element; illustrates another isometric view of the inverter unit of FIG. 4 depicting the other side thereof; illustrates an isometric view of the inverter unit of FIG. 4 along with glue applied along a periphery of a PCB in cured state; illustrates an exploded view of the inverter unit of FIG. 4 and inverter housing assembly; illustrates schematic cross sectional representation of the inverter unit received inside an inverter housing in accordance with another embodiment, wherein a PCB is connected to a separator element that is glued to the inverter housing, also is illustrated an enlarged view depicting the glued connection; illustrates schematic cross sectional representation of the inverter unit in accordance with yet another embodiment, wherein a PCB and a separator element are glued to the inverter housing, also is illustrated an enlarged view depicting the glued connection; illustrates the PCB and the separator element both mounted on and forming glue connection with different sections of the screw hub in accordance with an embodiment of the present invention; and illustrates the PCB and the separator element both mounted on and forming glue connection with a stem portion extending from the screw hub in accordance with an embodiment of the present invention. It must be noted that the figures disclose the invention in a detailed enough way to be implemented, said figures helping to better define the invention if needs be. The invention should however not be limited to the embodiment disclosed in the description.

DETAILED DESCRIPTION

Although the present invention is explained in the forthcoming description and the accompanying drawings, with an example of a motor driven compressor for a vehicle air conditioning system, wherein a Printed Circuit Board, hereinafter referred to as PCB for controlling an electric motor is securely held inside an inverter housing to prevent vibration of unfixed portions for example the peripheral portions, thereof. More specifically, the PCB is securely held inside the housing by fixing spaced-apart portions of the Printed Circuit Board to the inverter housing by means of fixing means such as screws, whereas at least one of the unfixed portions of the PCB are glued to the elements adjacent to the PCB for example, to the inventor housing to prevent vibration of the PCB. The glued fixing of at least one of the unfixed portions of the PCB prevents problems such as noise and reliability issues caused by the vibration of such unfixed portions of the PCB. However, the present invention is also applicable in other vehicular and non-vehicular applications, wherein unfixed portions or free peripheral portions of a PCB or any other planar element disposed within a housing is required to be securely held by gluing the same to adjacent elements such as for example, the housing itself to prevent problems such as noise, reliability issues and the vibrating portions interfering with operation of other adjacent elements.
The present envisages a motor driven compressor 100 as illustrated in FIG. 1. The motor driven compressor 100 includes a compression unit 110, an electric motor 120 and an inverter unit 130.
The compressor unit 110 and the electric motor 120 are received in a main housing 110a having a compressor accommodating space and an electric motor accommodating space. More specifically, the compressor unit 110 is received in the compressor accommodating space, while the electric motor 120 is received in the electric motor receiving space of the main housing 110a. The main housing 110a may be formed as a single part having the compressor accommodating space and the electric motor accommodating space or may be formed as separated parts having the compressor accommodating space and the electric motor accommodating space respectively. The compression unit 110 is functionally coupled to and is driven by the electric motor 120. The compression unit 110 in operating configuration thereof compresses a fluid particularly, a refrigerant flowing through an air conditioning loop. The inverter unit 130, hereinafter, simply referred to as inverter 130 is disposed inside an inverter housing 140 and includes a Printed Circuit Board 200 (not shown in FIG. 1), herein after referred to as a PCB 200. The PCB 200 is configured with a plurality of electronic components 210 mounted thereon and controls the electric motor.120. The inverter housing 140 is either integrally formed with the main housing 110a or separate from the main housing 110a.
In case the inverter housing 140 is separate from the main housing 110a, the inverter housing 140 includes an end wall 140a, a peripheral wall 140b extending from the periphery of the end wall 140a to define a PCB accommodation space and an open end of the inverter housing 140 closed by a cover 140c. In one embodiment, the cover 140c can be a removable cover 140c that is removably secured to the peripheral wall 140b of the inverter housing 140 by means of bolts 132 to provide access to the interior of the inverter housing 140. The PCB accommodation space of the inverter housing 140 is disposed adjacent to the electric motor accommodating space of the main housing 110a. The electric motor 120 is driven and controlled by the PCB 200. Specifically, the PCB 200 is functionally coupled to the electric motor 120 via a connector element 230 and controls operation of the electric motor 120. The connector element 230 extends from the PCB held inside the PCB accommodating space to the electric motor held inside the electric motor accommodating space.
The cover 140c protects the PCB 200 positioned in the PCB accommodation space from external shocks and external environmental conditions such as dust, moisture etc. that can be detrimental to the PCB 200 and other electronic components held in the inverter housing 140. The inverter housing 140 and the cover 140c are generally of a metallic material for providing sufficient stiffness to the structure thereof and prevent transmission of electromagnetic noise therethrough.
The inverter unit 130 generally includes a PCB 200 received inside the inverter housing 140. Particularly, the Printed Circuit Board 200 is fixed to the inverter housing 130 by fixing spaced-apart portions of the Printed Circuit Board 200 to the inverter housing 130 by means of fixing means, while the remaining portions of Printed Circuit Board 200 remain unfixed. The fixing means are in the form of screws 134 threadably engaging with holes formed on the screw hubs 144. More specifically, the spaced apart portions of the PCB 200 are supported on and fixed to the screw hubs 144 formed on the inverter housing 140 by means of screws 134. The screw hubs 144 extend from the end wall 140a of the inverter housing 140 towards the cover 140c and the holes on the screw hubs 144 receive and threadably engage with screws 134 passing through the PCB 200. At least one of the unfixed portions 202 of the PCB 200 are glued to at least one of the screw hubs 144 and the inverter housing 140 to prevent vibration of the PCB 200.
Generally, the peripheral portion of the PCB 200 disposed inside the inverter housing 140 is likely to be subjected to vibration because of unrestricted movement thereof. The present invention envisages applying gluing fixation for arresting vibration of the peripheral portions of the PCB 200 or at least one of the unfixed and free to move portions of the PCB 200 that is likely to vibrate because of not being securely held. Particularly, at least one of the unfixed portions of the PCB 200 are are glued to elements adjacent thereto to prevent vibration of the PCB 200. In accordance with a preferred embodiment of the present invention as illustrated in FIG. 2, a portion of periphery of the PCB 200, being the unfixed portion, are glued to the peripheral wall 140b of the inverter housing 140 which is positioned adjacent to the periphery of the PCB 200, as will be explained later. Further, the PCB 200 is supported over and glued to at least one screw hub 144 extending from the end wall 140a towards the cover 140c. Other than the peripheral portion of the PCB 200, there are other unfixed portions such as portions of the PCB 200 that are not fixed by the fixing means. The PCB 200 can be glued to other portions of the inverter housing 140 that are positioned adjacent to the PCB, particularly, adjacent to the unfixed portions of the PCB 200 such as for example, the raised platform 146. The screw hub 144 apart from being configured with threaded hole to receive and form threaded engagement with the screw 134 for mounting the PCB 200 to the end wall 140a also provides surface area for receiving glue and forming glued fixation with the PCB 200 supported thereon. The glued fixation of the PCB 200 to the screw hubs 144 restrict any angular vibration of the PCB 200 along the axis of the screw hub 144/ screws 134 that is not restricted by the fixing means. However, glued fixation between the PCB 200 and the screw hubs 144 is optional.
Referring to the FIG. 2 of the accompanying drawings, at least a portion of the periphery of the PCB 200 is disposed between the peripheral wall 140b and the cover 140c of the inverter housing 140. Specifically, at least one of the peripheral wall 140b and the cover 140c is formed with a cutout 142b, 142c that forms a cavity 142 to receive at least a portion of the periphery of the PCB 200 and the glue 150 to form glue connection with at least one side of the PCB 200. More specifically, the peripheral wall 140b is formed with a first cut out 142b and the cover 140c is formed with a second cut out 142c. When the cover 140c is assembled to the peripheral wall 140b by means of bolts 132, the second cut out 142c is aligned with the first cutout 142b to form the cavity 142. The cavity 142 so formed receives at least a portion of the periphery of the PCB 200 and the glue 150 to form glue connection of the inverter housing 140 with both sides of the PCB 200. Specifically, the uncured glue received in the cavity 142 flows along unrestricted path and wherever there is space, for example between the cover 140c and the peripheral wall 140b of the inverter housing 140 and around the at least a portion of the periphery of the PCB 200 received in the cavity 142 and once cured, the glue forms glued fixation between the inverter housing 140 and both sides of the PCB 200. FIG. 3 illustrates an enlarged view depicting a portion of the cured glue 150 forming connection between the PCB 200 and the inverter housing 140. More specifically, referring to the FIG. 2, a portion 150a of the cured glue 150 forms glued fixation between the PCB 200 and the cover 140c on one side of the PCB 200 and another portion 150b of the cured glue 150 forms glued fixation between the PCB 200 and the peripheral wall 140b on the other side of the PCB 200. Further, still another portion 150e of cured glue forms sealing connection between the between the cover 140c and the peripheral wall 140b of the inverter housing 140. The cavity 142 also provides support to at least a portion of the periphery of the PCB 200. Accordingly, both sides of at least a portion of the periphery of the PCB 200 is secured by glued fixation and vibration thereof along both directions is arrested. FIG. 3 illustrates an enlarged view depicting a portion of the cured glue 150 for forming connection between the PCB 200 and the inverter housing 140.
In accordance with another embodiment of the present invention, the PCB 200 includes, extended unfixed portions that are received between the peripheral wall 140b and the cover 140c of the inverter housing 140. Specifically, at least one of the peripheral wall 140b and the cover 140c is formed with a cutout 142b, 142c that forms a cavity 142 to receive the extended, unfixed portion of the PCB 200 and the glue 150 to form glue connection with at least one side of the PCB 200.
In accordance with an embodiment of the present invention, the inverter unit 130 also includes a separator element 220. Referring to the FIG. 4 and FIG. 5, the separator element 220 is of insulating material and separates the electronic components 210 mounted on the PCB 200. In some cases, the separator element 220 also positions the PCB 200 inside the inverter housing 140. More specifically, the PCB 200 is secured to the separator element 220 by any means such as rivets and the assembly of the PCB 200 and the separator element 220 is mounted within the inverter housing 140. Alternatively, the PCB 200 and the separator 220 are aligned and removably assembled to each other and the assembly of the PCB 200 and the separator 220 is mounted to the end wall 140a to securely hold the assembly of the PCB 200 and the separator 220 inside the inverter housing 140. FIG. 7 illustrates an exploded view of the inverter 130 and inverter housing 140 assembly, also is depicted the separator 220 and the sealing element 150 formed by the cured glue. FIG. 6 illustrates an isometric view of the inverter unit 130 along with glue applied along a periphery of the PCB 200 in cured state.
At least one of the Printed Circuit Board 200 and the separator element 220 is fixed to the inverter housing 140 by fixing spaced-apart portions of at least one of the Printed Circuit Board 200 to the inverter housing 130 by means of fixing means. More specifically, at least one of the PCB 200 and the separator element 220 is supported on and fixed to the screw hubs 144 formed on the inverter housing 140 by means of the screws 134. The threaded holes formed on the respective screw hubs 144 receive and engage with screws 134 passing through at least one of the PCB 200 and the separator element 220. The screw hubs 144 extend from the end wall 140a towards the cover 140c and the holes on the screw hubs 144 receive and threadably engage with screws 134 passing through at least one of the PCB 200 and the separator element 220.
Due to space limitations within the inverter housing 140, the screw hubs 144 are widely spaced with respect to each other. Further, the electronic components 210 depending from the PCB 200 also prevent the screw hubs 144 from being closely spaced with respect to each other. More specifically, although, the screws 134 engaging with the corresponding screw hubs 144 support spaced apart portions of at least one of the PCB 200 and the separator element 220 inside the inverter housing 140, however, remaining portions of at least one of the PCB 200 and the separator element 220 remain unfixed due to various constraints. Particularly, the space constraints inside the inverter housing 140, creepage constraints and the PCB 200 subjected to strains if the mounting screws are disposed close to each other result in some portions of the PCB 200 remaining unfixed. More specifically, at least some portions of the PCB 200 and the separator element 220 remain insufficiently supported and are free to move inside the inverter housing 140. The unfixed and free to move portions of the PCB 200 and the separator element 220 are likely to be subjected to vibrations that cause various problems such as noise and reliability issues. The movement or vibration of the PCB 200, the separator element 220 may also cause such elements to interfere with adjacent elements disposed inside the inverter housing 140. The vibration of the PCB 200 can also be detrimental to the delicate electronic components 210 mounted on the PCB 200 and adversely impact the service life and reliability of the PCB 200.
In order to overcome the problems caused by the vibration of the unfixed and free to move portions of the PCB 200, the separator element 220 or any other planar element disposed inside the inverter housing 140, such portions are glued to adjacent elements to securely hold such elements and prevent any movement or vibration thereof. Generally, at least one of the PCB 200 and the separator element 220 is glued to the inverter housing 140.
More specifically, at least a portion of a periphery of the PCB 200 is glued to at least one of the separator element 220 and the inverter housing 140. FIG. 6 illustrates an isometric view of the inverter unit 130 along with the glue 150 applied along the periphery of the PCB 200 in cured state. The glue 150 applied along the periphery of the PCB 200 when cured forms a sealed connection between the PCB 200 and the inverter housing 140. More specifically, the glued connection acts as a sealing for preventing dust, moisture and other foreign particles from entering inside the inverter housing 140. Generally, the glue 150 is silicon based epoxy resin. However, the present invention is not limited to any particular type of the glue as far as the glue is capable of configuring a secure glue fixation between the elements. Generally, the glue once cured forms secure glue fixation between at least one of peripheral portions of the PCB 200, the separator element 220, elements disposed adjacent to the PCB 200 and the separator element 220 and the inverter housing 140. Particularly, the glue once cured forms secure glue fixation between the inverter housing 140 and the peripheral portions of at least one of the PCB 200 and the separator element 220.
In accordance with one embodiment of the present invention, at least a portion of the periphery of the PCB 200 or at least one of the unfixed and free to move portions of the PCB 200 is glued to the separator element 220 that in turn is mounted to the inverter housing 140. According to another embodiment, the PCB 200 is secured to the separator element 220 and at least a portion of the periphery of the separator element 220 or at least one of the unfixed and free to move portions of the separator element 220 is glued to the inverter housing 140. More specifically, the PCB 200 is supported over and secured to the separator element 220 received, positioned and held within the inverter housing 140 and at least one of the unfixed portions 222 of the separator element 220 is glued to elements adjacent to the separator element 220 or to the inverter housing 140 to prevent vibration of the separator element 220. The portion of periphery of the separator element 220, being the unfixed portion, are glued to the peripheral wall 140b of the inverter housing 140 which is positioned adjacent to the periphery of the separator element 220. Further, separator element 220 is supported over and glued to at least one screw hub 144 extending from the end wall 140a towards the cover 140c. Other than the peripheral portion of the separator element 220, there are other unfixed portions such as portions of separator element 220 that are not fixed by the fixing means. The separator element 220 can be glued to other portions of the inverter housing 140 that are positioned adjacent to the separator element 220, particularly, adjacent to the unfixed portions of the separator element 220 such as for example, the raised platform 146. This way, the peripheral portions of the PCB 200 or any unfixed or free to move portion thereof is indirectly secured to the inverter housing 140 and vibration thereof is prevented. In accordance with yet another embodiment of the present invention, at least a portion of the periphery of the PCB 200 or any unfixed and free to move portion thereof is directly glued to the inverter housing 140. This way, the peripheral portions of the PCB 200 or any unfixed and free to move portions thereof is directly secured to the inverter housing 140 and prevented from vibration. By preventing vibration of the PCB, the separator element, any noise due to vibration of components is avoided and silent operation of the compressor is achieved.
Alternatively, the PCB 200 is connected to the separator element 220 and at least one of the unfixed portions 222 of the separator element 220 is glued to at least one of the screw hubs 144 and the inverter housing 140. Referring to the FIG. 8 of the accompanying drawings, at least a portion of a periphery of the separator element 220 is glued to the inverter housing 140. Generally, at least a portion of a periphery of the separator element 220 is disposed between the peripheral wall 140b and the cover 140c. Specifically, at least one of the peripheral wall 140b and the cover 140c is formed with a cut-out 142b, 142c that forms a cavity 142 to receive at least a portion of a periphery of the separator element 220 and the glue 150 to form glue connection with at least one side of the separator element 220. The peripheral wall 140b and the cover 140c are formed with the respective first and second cutouts 142b and 142c that are aligned to each other to form the cavity 142 to receive at least a portion of a periphery of the separator element 220 and the glue 150 to form glue connection of the inverter housing 140 with both sides of the separator element 220. Specifically, the uncured glue received in the cavity 142 flows around the at least a portion of the periphery of the separator element 220 received in the cavity 142 and once cured, the cured glue 150 forms glued fixation between the inverter housing 140 and both sides of the separator element 220. More specifically, a portion 150c of the cured glue 150 forms glued fixation between the separator element 220 and the cover 140c on one side of the separator element 220 and another portion 150d of the cured glue 150 forms glued fixation between the separator element 220 and the peripheral wall 140b on the other side of the separator element 220. Further, still another portion 150e of cured glue forms sealing connection between the between the cover 140c and the peripheral wall 140b of the inverter housing 140. The cavity 142 also provides support to at least a portion of the periphery of the separator element 220. Accordingly, both sides of at least a portion of the periphery of the separator element 220 is secured by glued fixation and vibration thereof along both directions is arrested.
In accordance with yet another embodiment of the present invention as illustrated in FIG. 9, at least a portion of a periphery of PCB 200 and the separator element 220 is disposed between the peripheral wall 140b and the cover 140c. The peripheral wall 140b and the cover 140c are formed with the respective first and second cutouts 142b and 142c aligned to each other to form the cavity 142 that receives the glue 150 and at least a portion of a periphery of the PCB 200 and the separator element 220 to form glue connection between the PCB 200 and the cover 140c on one side and between the separator element 220 and the peripheral wall 140b on the other side. More specifically, a portion 150a of the cured glue 150 forms glued fixation between the PCB 200 and the cover 140c on one side and another portion 150d of the cured glue 150 forms glued fixation between the separator element 220 and the peripheral wall 140b on the other side. Further, still another portion 150e of cured glue forms sealing connection between the between the cover 140c and the peripheral wall 140b of the inverter housing 140. The cavity 142 also provides support to at least a portion of the periphery of the PCB 200 and the separator element 220. Accordingly, both sides of at least a portion of the periphery of the PCB 200 and the separator element 220 is secured by glued fixation and vibration thereof along both directions is arrested.
In accordance with another embodiment of the present invention as illustrated in FIG. 10, both the PCB 200 and the separator element 220 are supported over and fixed to at least one of the screw hubs 144 by means of interference fit. Further, at least one of the PCB 200 and the separator element 220 is fixed to the screw hubs 144 by means of glue connection 150. More specifically, the PCB 200 and the separator element 220 include different sized holes aligned to each other to receive different sections of the screw hub 144 of different dimensions and are secured to the different sections of the screw hubs 144 by means of glue connection. Such configuration prevents the sliding of the PCB 200 and the separator element 220 with respect to the screw hub 144, whereas the screws 134 mount the PCB 200 and the separator element 220 on the screw hub 144. Further, the screw head 134a of the screw 134 is in contact with the PCB 200 to urge the PCB 200 and the separator element 220 against the screw hub 144.
FIG. 11 illustrates the PCB and the separator element both mounted on and forming glue connection with a stem portion extending from the screw hub in accordance with an embodiment of the present invention.
If in case space is not available for forming glue fixation between inverter housing 140 and at least one of the unfixed portion 202 of the PCB 200 and the separator element 220, additional platforms 146 are formed within the inverter housing 140. More specifically, the inverter housing 140 is formed with a raised platform 146 depicted in FIG. 2, FIG. 8 - FIG. 9 to provide support to at least one of the PCB 200 and separator element 220 and also provide surface to form glue connection with the unfixed portion 202, 222 of at least one of the PCB 200 and the separator element 220.
The glue 150 after being cured forms a secure connection between the inverter housing 140 and unfixed, free to move portions of at least one of the PCB 200 and the separator element 220, thereby preventing vibration thereof and addressing problems arising due to the vibration of such portions.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described herein.
In any case, the invention cannot and should not be limited to the embodiments specifically described in this document, as other embodiments might exist. The invention shall spread to any equivalent means and any technically operating combination of means.

Claims

A motor driven compressor (100) comprising:
a compression unit (110) received in a main housing (110a) and compressing a refrigerant fluid;
an electric motor (120) also received in the main housing (110a) and driving said compression unit (110);
an inverter unit (130) comprising a Printed Circuit Board (200) configured with a plurality of electronic components (210) mounted thereon and adapted to control said electric motor (120);
an inverter housing (140) comprising an end wall (140a), a peripheral wall (140b) and a cover (140c) defining an interior space adapted to receive, position and hold the Printed Circuit Board (200) therein, the Printed Circuit Board (200) is fixed to the inverter housing (130) by fixing spaced-apart portions of the Printed Circuit Board (200) to the inverter housing (130) by means of fixing means, while the remaining portions of Printed Circuit Board (200) remain unfixed,
characterized in that at least one of the unfixed portions (202) of the Printed Circuit Board (200) is glued to elements adjacent thereto to prevent vibration of the Printed Circuit Board.
The motor driven compressor (100) as claimed in the previous claim, wherein at least a portion of a periphery of the Printed Circuit Board (200) is disposed between the peripheral wall (140b) of the inverter housing (140) and the cover (140c).
The motor driven compressor (100) as claimed in any of the preceding claims, wherein at least one of the peripheral wall (140b) and the cover (140c) is formed with a cutout (142b, 142c) that forms a cavity to receive at least a portion of the periphery of the Printed Circuit Board (200) and a glue (150) to form glue connection with at least one side of the Printed Circuit Board (200).
The motor driven compressor (100) as claimed in any of the preceding claims, wherein the peripheral wall (140b) and the cover (140c) are formed with the respective first and second cutouts (142b) and (142c) aligned to each other to form a cavity (142) that receives at least a portion of a periphery of the Printed Circuit Board (200) and the glue (150) to form glue connection with both sides of the Printed Circuit Board (200).
The motor driven compressor (100) as claimed in any of the preceding claims, wherein the Printed Printed Circuit Board (200) is supported over and secured to a separator element (220) received, positioned and held within the inverter housing (140), at least one of the unfixed portions (222) of the separator element (220) is glued to elements adjacent thereto to prevent vibration of the separator element (220).
The motor driven compressor (100) as claimed in any of the preceding claims, wherein at least one of the Printed Circuit Board (200) and a separator element (220) is supported over and glued to at least one screw hub (144) extending from the end wall (140a) towards the cover (140c) and adapted to receive the fixing means in the form of a mounting screw (134) for fixing at least one of the Printed Circuit Board (200) and the separator element (220) to the end wall (140a) .
The motor driven compressor (100) as claimed in any of the preceding claims, wherein at least a portion of a periphery of the Printed Circuit Board (200) is glued to at least one of a separator element (220) and the inverter housing (140).
The motor driven compressor (100) as claimed in claim 5, wherein at least a portion of a periphery of the separator element (220) is glued to the inverter housing (140).
The motor driven compressor (100) as claimed in claim 5, wherein at least a portion of a periphery of the separator element (220) is disposed between the peripheral wall (140b) and the cover (140c).
The motor driven compressor (100) as claimed in claim 5, wherein at least one of the peripheral wall (140b) and the cover (140c) is formed with a cut-out that forms a cavity to receive at least a portion of a periphery of the separator element (220) and a glue (150) to form glue connection with at least one side of the separator element (220).
The motor driven compressor (100) as claimed in in claim 5, wherein the peripheral wall (140b) and the cover (140c) are formed with respective first and second cutouts aligned to each other to form a cavity to receive at least a portion of a periphery of the separator element (220) and the glue (150) to form glue connection with both sides of the separator element (220).
The motor driven compressor (100) as claimed in claim 5, wherein at least a portion of a periphery of the Printed Circuit Board (200) and the separator element (220) is disposed between the peripheral wall (140b) and the cover (140c).
The motor driven compressor (100) as claimed in claim 5, wherein the peripheral wall (140b) and the cover (140c) are formed with respective first and second cutouts aligned to each other to form a cavity that receives a glue (150) and at least a portion of a periphery of the Printed Circuit Board (200) and the separator element (220) to form glue connection between the Printed Circuit Board (200) and the cover (140c) on one side and between the separator element (220) and the peripheral wall (140b) on the other side.
The motor driven compressor (100) as claimed in claim 5, wherein the unfixed portion (202) of the Printed Circuit Board (200) is glued to at least one of the inverter housing (140) and the separator element (220).
The motor driven compressor (100) as claimed in the claim 5, wherein the unfixed portion (222) of the separator element (220) is glued to the inverter housing (140).
The motor driven compressor (100) as claimed in the claim 3, wherein a portion of cured glue (150) forms sealing connection between the between the cover (140c) and the peripheral wall (140b) of the inverter housing (140).
The motor driven compressor (100) as claimed in any of the preceding claims, wherein the inverter housing (140) is formed with at least one raised platform (146) extending from end wall (140a) towards the cover (140c) and adapted to provide support to and form glue connection with the unfixed portion (202, 222) of at least one of the Printed Circuit Board (200) and a separator element (220).
The motor driven compressor (100) as claimed in any of the preceding claims, wherein the glue is silicon based epoxy resin.
The motor driven compressor (100) as claimed in claim 6, the PCB (200) and the separator element (220) both are mounted on and forming glue connection with a stem portion extending from the screw hub (144).
The motor driven compressor (100) as claimed in claim 6, wherein the PCB (200) and the separator element (220) comprises different sized holes aligned to each other and adapted to receive different sections of the screw hub (144) of different dimensions and are secured to the different sections of the screw hubs (144) by means of glue connection (150), wherein the screw head (134a) presses the PCB (200) and the separator element (220) against the screw hub (144).