Electric machine

Abstract

An electric machine (100) includes a machine (110), an electric motor (120), an inverter (130) and an electrical connector (150, 160). The electric motor (120) drives the machine (110). The inverter (130) received and held in an inverter housing (132) and adapted to process and regulate electrical power being supplied to the electric motor (120). The inverter (130) comprising a printed circuit board (140). The electrical connector (150, 160) mounted on an end wall (134a) of the inverter housing (132) and comprising a conductive member (152, 162) penetrating through the end wall (134a). A first end (152a, 162a) of the conductive member (152, 162) electrically connected to an input portion (140a, 140b) of the printed circuit board (140) via a bus-bar (170, 180, 190). There is at least one dis-connectable coupling (173, 175, 183, 185, 195) between the conductive member (152, 162) and the input portion (140a, 140b).

Description

ELECTRIC MACHINEField of Invention

[0001] The present invention relates to an electric machine, more particularly, the present invention relates to an electrical coupling between elements of an electric driven compressor.Background of the Invention

[0002] Generally, an electric driven compressor includes a compression mechanism, an electric motor driving the compression mechanism, and an inverter for regulating and supplying electrical power to the electric motor. The inverter includes a printed circuit board and various electronic components mounted thereon. The inverter is received and held inside an inverter housing that comprises a front head and a cover. Generally, electric power is supplied from an external power source to the printed circuit board via an electrical connector mounted on a wall of the inverter housing.

[0003] As a conventional configuration, EP patent document EP2169231 discloses an electric compressor having a compression mechanism, an electric motor, and an inverter. In this configuration, as illustrated in FIG. 1, a printed circuit board 3 is received in an inverter housing 2 and an electrical connector 4 is mounted on an external wall of the inverter housing 2. Lead frames 4a of the electrical connector 4 are aligned with apertures 3a formed through a printed circuit board 3. The lead frames 4a are inserted straight into the apertures 3a and soldered, thus achieving direct and permanent electric connection between the electrical connector 4 and the printed circuit board 3. However, in such a connection, it is impossible to disassemble the printed circuit board 3 without de-soldering the connection between the printed circuit board 3 and the lead frames 4a. Therefore, such arrangement faces serviceability issues as it is hard to replace a printed circuit board with a new one when an error or a problem is detected in the printed circuit board. Further, this connection structure can ft be applied to a configuration in which a connector is placed offset from apertures of the printed circuit board.

[0004] Accordingly, there is a need for an electric machine, particularly, an electric driven compressor that addresses serviceability issues faced by conventional electric driven compressors. Further, there is a need for an electric machine that involves robust connection and electrical coupling between the components thereof. Furthermore, there is a need for an electric machine that is compact and addresses packaging issues. Still further, there is a need for an electric machine that allows connection between the lead frames extending from the electrical connectors and the apertures formed on the printed circuit board, even when connectors are placed offset from the apertures.Summary of the Invention

[0005] (OBJECTS)

[0006] An object of the present invention is to provide an electric device, particularly, an electric driven compressor that obviates the drawbacks of the conventional electric driven compressor that addresses the serviceability issues, is efficient and reliable.

[0007] Another object of the present invention is to provide an electric driven compressor that allows connection between the lead frames extending from the electrical connectors and the corresponding apertures formed on the printed circuit board even when connectors are placed offset from the apertures.

[0008] 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.

[0009] 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.

[0010] (SUMMARY)

[0011] An electric machine includes a machine, an electric motor, an inverter and an electrical connector. The electric motor drives the machine, particularly, a compressor. The inverter is received and held in an inverter housing and adapted to process and regulate electrical power being supplied to the electric motor from an external power source. The inverter comprising a printed circuit board. The electrical connector is mounted on a wall of the inverter housing. The electrical connector comprising a conductive member penetrating through the wall. A first end of the conductive member is electrically connected to an input portion of the printed circuit board via a bus-bar. There is at least one dis-connectable coupling between the conductive member and the input portion.

[0012] Since there is at least one dis-connectable coupling between the conductive member and the input portion, the printed circuit board can be replaceable when some trouble is detected in the PCB

[0013] The electric machine further comprising a socket terminal mounted on and electrically coupled to the input portion of the printed circuit board, wherein a first end of a socket terminal is adapted to be fixed to the input portion and a second end of the socket terminal is provided with a first engagement element. A first end of the bus-bar is connected to the first engagement element of the socket terminal to form the first dis-connectable coupling.

[0014] Generally, the first end of the bus-bar is configured with second engagement element adapted to be directly engaging with and electrically coupled to the socket terminal.

[0015] Further, a second end of the bus-bar is provided with a third engagement element. The first end of the conductive member is connected to and electrically coupled to the third engagement element of the bus-bar to form the second dis-connectable coupling.

[0016] Particularly, position (A) of the conductive member of the electrical connector mounted on the wall of the inverter housing is offset with position (B) of the input portion of the printed circuit board. The bus-bar has a bended portion between the first end and the second end so as to adapt the offset positions (A, B).

[0017] Particularly, the portions of the bus-bar on opposite sides of the bended portion are at an angle with respect to each other.

[0018] In accordance with another embodiment of the present invention, the bus-bar is over-molded by a first resin housing.

[0019] Further, the first resin housing is formed with reinforcement ribs.

[0020] Particularly, the first resin housing of the bus-bar is fixed on the inverter housing.

[0021] More specifically, the first resin housing comprises at least one mounting hole aligned to corresponding hole formed on a front head for passage of mounting bolt there through.

[0022] Generally, the mounting bolt remains accessible when the printed circuit board is mounted on the front head.

[0023] More specifically, the printed circuit board comprises an access hole formed thereon and adapted to provide access to the mounting bolt when the printed circuit board is securely mounted to the housing.

[0024] Also, the socket terminal is over-molded by a second resin housing. The second resin housing is fixed on the printed circuit board.

[0025] Generally, the first end of the socket terminal comprises terminals adapted to be secured to and electrically coupled to the input portion of the printed circuit board. The terminal further being in electrical contact with the first engagement elements.

[0026] Further, the first resin housing comprises a positioning member extending along the bus-bar towards the first end and adapted to be received in a flanged hole formed on the socket terminal.

[0027] Generally, substantial portion of the electrical connector is disposed outside the inverter housing.

[0028] In accordance with yet another embodiment of the present invention, the bus-bar comprises first lead frames and second lead frames. The first lead frames adapted to be soldered to the input portion of the printed circuit board and the second lead frames adapted to engage with the first end of the conductive member to form the dis-connectable coupling there with.

[0029] 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:

[0030] FIG. 1 illustrates an exploded view of an inverter module of a conventional electric driven compressor;

[0031] FIG.2 illustrates a schematic representation of an electric driven compressor in accordance with an embodiment of the present invention;

[0032] FIG. 3 illustrates an isometric view of an electrical connection in accordance with an embodiment, wherein a bus-bar with a first resin housing over-molded thereon forms at least one dis-connectable coupling between an electrical connector and a printed circuit board;

[0033] FIG. 4 illustrates a schematic representation of an inverter configured with the electrical connection of FIG. 3;

[0034] FIG. 5 illustrates an isometric view of the bus-bar of FIG. 3;

[0035] FIG. 6 illustrates an isometric view of bus-bar of FIG. 3 without the first resin housing and forming the electrical connection;

[0036] FIG. 7 illustrates a sectional view depicting a first engagement element of a socket terminal forming a first dis-connectable coupling with a second engagement element of the bus-bar of FIG. 3;

[0037] FIG. 8 illustrates a sectional view depicting a third engagement element of the bus-bar forming a second dis-connectable coupling with a conductive member of an electrical connector of FIG. 3;

[0038] FIG. 9 illustrates an exploded view of a socket terminal of FIG. 7 with respect to the printed circuit board, the socket terminal adapted configure dis-connectable coupling with the bus-bar;

[0039] FIG. 10 illustrates an exploded view of the inverter configured with socket terminal of FIG. 9 and depicting relative arrangement between various elements of the inverter, the bus-bar is arranged inside an inverter housing and the electrical connector is disposed outside the inverter housing;

[0040] FIG. 11 illustrates an isometric view of an inverter in accordance with another embodiment configured with a socket terminal with resin housing, wherein one end of the bus-bar is electrically coupled to and dis-connectably connected the printed circuit board via the socket terminal;

[0041] FIG. 12 illustrates a schematic representation of an inverter configured with the electrical connection of FIG. 11

[0042] FIG. 13 illustrates an isometric view of the socket terminal of FIG. 11;

[0043] FIG. 14 illustrates another isometric view of the socket terminal of FIG. 11;

[0044] FIG. 15 illustrates a sectional view of the socket terminal of FIG. 11 depicting internal details thereof and electrical connection between input portion of the printed circuit board and a first end of the bus-bar; and

[0045] FIG. 16 illustrates an isometric view of a bus-bar in accordance with another embodiment adapted to configure electrical connection between a low voltage electrical connector and a printed circuit board.Detailed Description of the Invention

[0046] The present invention is described with example of inverter of an electric driven compressor, particularly, the inverter of the present invention involves at least one dis-connectable electrical coupling between elements thereof and electrical connectors to improve serviceability of the inverter. More specifically, the present invention involves dis-connectable electrical coupling between electrical connectors and a printed circuit board of the inverter by means of bus-bar for improved serviceability of the inverter. The present invention also addresses the packaging issues by achieving offset mounting of the electrical connector with respect to connection interface between the bus-bar and the printed circuit board. The present invention enables angular positioning of the electrical connectors with respect to the printed circuit board to further address the packaging issues. However, the present invention is also applicable to any electronic system used in vehicular and non-vehicular applications, wherein electrical connectors are required to be dis-connectably connected to the electronic components, such as printed circuit board to improve the serviceability and the electrical connectors are required to be angularly positioned or offset mounted with respect to the electronic components such as for example printed circuit board to address packaging issues.

[0047] The present invention envisages an electric machine, particularly, an electric driven compressor 100. Referring to FIG. 2, the electric driven compressor 100 is illustrated. The electric driven compressor 100 comprises an electric machine 110, for example a compressor unit, an electric motor 120 and an inverter 130.

[0048] The compressor unit 110 is received in an enclosure defined by a compressor housing 110a. The compressor housing 110a is an open ended housing that includes an end wall and peripheral wall. The compressor unit 110 compresses a fluid, particularly, a refrigerant flowing through an air-conditioning loop of a vehicle air-conditioning system. The compressor unit 110 is generally a scroll type compressor. However, the present invention is not limited to any particular configuration of the compressor unit 110. The compressor housing 110a protects the compressor unit 110 against harmful external environment conditions.

[0049] The electric motor 120 is received and held in a motor housing 120a. The electric motor 120 drives the compressor unit 110. In accordance with an embodiment, the motor housing 120a is also an open ended housing that includes an end wall and peripheral wall disposed along a periphery of the end wall.

[0050] The inverter 130 is received and held in an inverter housing 132. The inverter housing 132 is of larger radial dimension compared to the motor housing 120a and at least a portion of the inverter housing 132 extends beyond the motor housing 120a to provide space for mounting of at least one electrical connector 150, 160 to the inverter housing 132. The inverter housing 132 comprises a front head 132a and a cover 132b. The front head 132a is an open ended housing that includes an end wall 134a and a peripheral wall 138a disposed along a periphery of the end wall 134a. The front head 132a and the cover 132b are assembled together to define an enclosure that receives components, particularly electronic components such as for example a printed circuit board 140 to safeguard the electronic components from harmful external environment. The cover 132b is removable with respect to the front head 132a for accessing the components received in the front head 132a for service and maintenance.

[0051] The motor housing 120a is open ended separate housing arranged between the compressor housing 110a and the inverter housing 132. In one arrangement an open end of the motor housing 120a is abutting the end wall 134a or closed end of the inverter housing 132 and the end wall or closed end of the motor housing 120a is abutting open end of the compressor housing 110a to define separate enclosures for receiving the electric motor 120 and the compressor unit 110.

[0052] Alternatively, the closed ends or end walls of the motor housing 120a and the inverter housing 132 are abutting each other and the open ends of the motor housing 120a and the compressor housing 110a are abutting each other to define a common enclosure for the electric motor 120 and the compressor unit 110.

[0053] In accordance with yet another embodiment, the motor housing 120a and the front head 132a of the inverter housing 132 are formed integrally with two open ends opposite to each other and a common wall between the front head 132a and the motor housing 120a. The first open end is closed by open end of the compressor housing 110a to define a common enclosure for the electric motor 120 and the compressor unit 110. The second open end is closed by the cover 132b to define enclosure for receiving the inverter 130.

[0054] However, the present invention is not limited to any particular configuration and arrangement of the compressor housing 110a, the motor housing 120a and the inverter housing 132 as far as the compressor housing 110a, the motor housing 120a and the inverter housing 132 are capable of enclosing the compressor unit 110, the electric motor 120 and the inverter 130 to protect these against harmful external environment conditions.

[0055] Referring to the FIG. 4 of the accompanying drawings, the end wall 134a of the front head 132a comprises at least one first opening 136a, at least one first column 137 formed with a corresponding first mounting hole 137a and at least one second column 139 formed with a corresponding second mounting hole 139a. The first opening 136a receives at least a portion of corresponding the electrical connector 150 inside the inverter housing 132, particularly, a first end 152a of a conductive member 152 of the electrical connector 150. The inverter 130 further comprises the printed circuit board 140. A plurality of electronic components are mounted on the printed circuit board 140. Leads of the electronic components are inserted in apertures formed through the printed circuit board 140, and soldered on pads formed around the apertures. Conductive patterns are printed in the printed circuit board 140 for configuring electrical connection between the electric components. The printed circuit board 140 is supported on the columns 139 and securely mounted on the columns 139 by means of second mounting bolts 139b passing through aligned holes formed on the printed circuit board 140 and the columns 139. At least a portion of the periphery of the printed circuit board 140 is also supported between peripheral wall 138a of the front head 132a and the cover 132b. With such arrangement, the printed circuit board 140 is securely held inside the front head 132a in spaced apart configuration with respect to the end wall 134a. The inverter 130 processes and regulates electrical power being supplied to the electric motor 120 from an external power source for efficient operation of the electric motor 120. The inverter 130 further comprises at least one bus-bar 170, 180, 190 configuring dis-connectable electrical coupling between the printed circuit board 140 and the at least one electrical connector 150, 160.

[0056] In accordance with one embodiment of the present invention, the electrical connector 150 is a high voltage electrical connector as illustrated in FIG. 3 - FIG. 4, FIG. 6, FIG. 8, and FIG. 10 - FIG. 12 of the accompanying drawings.

[0057] The electrical connector 150 is mounted on the end wall 134a of the inverter housing 132. The electrical connector 150 is substantially disposed outside the inverter housing 132 to be frequently accessible from outside and conveniently removable from outside the inverter housing 132. In one example, at least a portion of the electrical connector 150 is received inside the inverter housing 132. More specifically, the electrical connector 150 comprises conductive members 152 and a flange portion 154. The first end 152a of the conductive member 152 is received inside the inverter housing 132 while the flange portion 154 remains outside the inverter housing 132. The flange portion 154 is formed with mounting holes 154a for passage of mounting bolts 156 there-through for mounting the electrical connector 150 to the inverter housing 132, particularly exterior of the inverter housing 132. The mounting holes 154a are aligned to corresponding apertures formed on the inverter housing 132, particularly outside surface of the inverter housing 132 for removably mounting the at least one electrical connector 15 on the inverter housing 132. In case the electrical connector 150 is damaged, the same can be disconnected from the inverter housing 132 and the corresponding bus-bar 170, 180 and replaced with new electrical connector, thereby improving the serviceability.

[0058] The electrical connector 150 is electrically coupled to and dis-connectably connected to the printed circuit board 140 via the bus-bar 170, 180 and a socket terminal 200, 300 to supply high voltage electrical power to the printed circuit board 140. The bus-bar 170, 180 configures dis-connectable connection between the electrical connector 150 and the printed circuit board 140. In accordance with one embodiment, the socket terminal 200 is directly secured to the printed circuit board 140.

[0059] FIG. 5 of the accompanying drawings illustrates an isometric view of the bus-bar 170 in accordance with an embodiment of the present invention. The bus-bar 170 is formed of metal strip, preferably copper. The bus-bar 170 includes second engagement elements 172 and third engagement elements 174 disposed on extreme ends 170a and 170b thereof. Referring to the FIG. 7, the second engagement elements 172 are male engagement elements in the form of terminals that are received in a first engagement elements 204 in the form of female engagement elements of the socket terminal 200 mounted on the printed circuit board 140 to configure dis-connectable connection and electrical coupling between a first end 170a of the bus-bar 170 and the socket terminal 200. More specifically, the socket terminal 200 includes a first end 200a and a second end 200b. The first end 200a of the socket terminal 200 includes a terminal end 202 received and secured to a hole formed at a first input portion 140a of the printed circuit board 140. More specifically, the terminal end 202 is secured to the input portion 140a of the printed circuit board 140 by soldering. The second end 200b of the socket terminal 200 comprises the first engagement element 204 in the form of female engagement element. The first engagement element 204 in the form of female engagement element comprises spring elements 204a that extend radially inwards towards each other to grip the second engagement elements 172 received in the first engagement element 204. The terminal end 202 being in electrical contact with the first engagement elements 204 and the first input portions 140a configure electrical contact between the first input portions 140a and the corresponding first engagement elements 204 via a conductive pattern printed in the printed circuit board 140. In accordance with one embodiment, the first engagement elements 204 are female engagement elements that receive corresponding second engagement elements 172 in the form of male engagement element extending from the first end 170a of the bus-bar 170. With such arrangement, the first end 170a of the bus-bar 170 is connected to and electrically coupled to the first engagement element 204 of the socket terminal 200 to form a first dis-connectable coupling 173. More specifically, the second engagement elements 172 formed on the first end 170a of the bus-bar 170 are adapted to directly engage with the first engagement element 204 of the socket terminal 200 to form the first dis-connectable coupling 173.

[0060] Referring to the FIG. 8 of the accompanying drawings, the third engagement elements 174 are female engagement elements in the form of socket terminal adapted to receive the first end 152a of the conductive member 152 to configure dis-connectable connection and electrical coupling between a second end 170b of the bus-bar 170 and the conductive member 152 of the electrical connector 150. More specifically, the third engagement elements 174 are in the form of female engagement element and comprises spring elements 174a that extend radially inwards towards each other to grip the first end 152a of the conductive members 152 received in the third engagement elements 174 in the form of female engagement elements.

[0061] With such configuration, the bus-bar 170 configures at least one dis-connectable coupling 173, 175 between the conductive member 152 of the electrical connector 150 and the first input portion 140a of the printed circuit board 140. The first dis-connectable coupling 173 configures dis-connectable connection between the bus-bar 170 and the socket terminal 200 mounted on the printed circuit board 140, while the second dis-connectable coupling 175 configures between the bus-bar 170 and the conductive member 152 of the electrical connector 150. The at least one dis-connectable coupling 173, 175 between the conductive member 152 and the first input portion 140a of the printed circuit board 140 permits convenient replacement of the printed circuit board 140 or the electrical connector 150, when either one of the printed circuit board 140 or the electrical connector 150 is damaged.

[0062] The bus-bar 170 is configured with at least one bended portion 178. The bended portion 178 of the bus-bar 170 enables offset positioning of the electrical connector 150 and the first input portion 140a of the printed circuit board 140 electrically coupled to each other by the bus-bar 170. Particularly, position A of the conductive member 152 of the electrical connector 150 mounted on the end wall 134a of the inverter housing 132 is offset with position (B) of the first input portion 140a of the printed circuit board 140. The bended portion 178 of the bus-bar 170 between the first end 170a and the second end 170b is configured to adapt the offset positions A, B. Such bended configuration of the bus-bar 170 permits the position A of the conductive member 152 of the electrical connector 150 mounted on the end wall 134a of the inverter housing 132 to be offset with position B of the first input portion 140a of the printed circuit board 140. The bended portion 178 of the bus-bar 170 also facilitates mounting of the electrical connector 150 at an angle with respect to the plane of the printed circuit board 140 as the portions of the bus-bar 170 on opposite sides of the bended portion 178 are at an angle with respect to each other. With such configuration of the bus-bar 170 with bended portion 178, the electrical connector 150 can be connected to and electrically coupled to the first input portion 140a of the printed circuit board 140 even though the positions A and B of the of the conductive member 152 and the first input portion 140a are not aligned.

[0063] The metallic strip of the bus-bar 170 is over-molded by a first resin housing 176. Particularly, the bus-bar 170 includes the first resin housing 176 formed over at least a portion of the metal strip forming the bus-bar 170 to provide rigidity thereto. Generally, the resin housing 176 is plastic over-molded over the metal strip forming the bus-bar 170. The first resin housing 176 is essentially formed over the bended portion 178 of the metal strip forming the bus-bar 170. The first resin housing 176 provides rigidity to the metal strip forming the bus-bar 170, particularly, the bended portion 178 of the metal strip to enable the bus-bar 170 to withstand deforming forces and prevent deformation and damage to the bus-bar 170. The first resin housing 176 comprises reinforcement ribs 176a formed thereon to further enhance rigidity of the bus-bar 170. Since the metal strip forming bus-bar 170 is over-molded by the first resin housing 176, the bended portion 178 of the bus-bar 170 can bear and keep its form when the offset axial force acts on the ends of the bus-bar 170 in the assembly / disassembly process. More specifically, the first resin housing 176 over-molded over the bus-bar 170 permits the bus-bar 170 with bended portion 178 to bear stresses without being deformed when the bus-bar 170 is being connected or dis-connected with respect to the electrical connector 150 or the socket terminal 200 by application of forces.

[0064] The first resin housing 176 of the bus-bar 170 is fixed on the inverter housing 132. More specifically, the first resin housing 176 further comprises at least one first mounting hole 176b as illustrated in FIG. 4. The first mounting hole 176b is aligned to the corresponding first mounting hole 137a of the first column 137 formed on the end wall 134a of the inverter housing 132 to receive a first mounting bolt 137b there-through. Such arrangement of the first mounting hole 137a, the first mounting hole 176b and the first mounting bolt 137b is for mounting the bus-bar 170 to the inverter housing 132, particularly, for mounting the bus-bar 170 to the front head 132a of the inverter housing 132. Particularly, such an arrangement facilitates positioning of the bus-bar 170 inside the front head 132a. The bus-bar 170 being securely mounted on the end wall 134a enables retaining of the bus-bar 170 in position within the front head 132a without requiring a jig when the printed circuit board 140 is being assembled / disassembled with respect to the front head 132a. In accordance with an embodiment, the first mounting bolt 137b is accessible from inside the front head 132a without removing the printer circuit board 140 from the front head 132a. The printed circuit board 140 is adapted to provide access to the first mounting bolt 137b. Particularly, the printed circuit board 140 comprises an access hole 142 formed thereon. The access hole 142 is accessible after removal of the cover 132b. The access hole 142 is aligned to the first mounting bolt 137b and adapted to provide access to the first mounting bolt 137b even when the printed circuit board 140 is mounted on the inverter housing 132. In accordance with another embodiment the first mounting bolt 137b is accessible from outside of the front head 132a. With such configuration of the access hole 142 formed on the printed circuit board 140 or the first mounting bolt 137b being accessible from outside of the front-head 132a, the assembly of the bus-bar 170 and the printed circuit board can be removed from the front head 132a after the electrical connector 150 is dis-connected from the third engagement element 174 and the bus-bar 170 is dismounted from the end wall 134a by loosening the first mounting bolt 137b.

[0065] The electrical connector 150 comprises a plurality of conductive members 152. In accordance with an embodiment of the present invention, the first end 152a of the conductive members 152 is in the form of terminals protruding from the electrical connector 150 as illustrated in FIG. 3 - FIG. 5, FIG. 6 and Fig. 8. The first end 152a of conductive members 152 in the form of terminals penetrate through the end wall 134a and electrically connect to the first input portion 140a of the printed circuit board 140 via the bus-bar 170. More specifically, the first end 152a in the form of the terminals penetrate through the end wall 134a and dis-connectably engage with third engagement elements 174 of the bus-bar 170 that are in the form of female engagement elements. Further, the second engagement elements 172 of the bus-bar 170 are in form of male engagement elements that dis-connectably engage with the socket terminal 200 secured to the printed circuit board 140.

[0066] In accordance with an embodiment of the present invention, the second engagement elements 172 of the bus-bar 170 are in form of female engagement elements that receive the male engagement elements, particularly terminals mounted on the first input portion 140a to dis-connectably engage with the terminal in form of male engagement elements secured to the printed circuit board 140. However, the present invention is not limited in any particular configuration, number and placement of the second engagement elements 172 of the bus-bar 170 as far as the second engagement elements 172 are adapted to dis-connectably engage with the terminal secured to the printed circuit board 140.

[0067] Further, in one example, the first end of the conductive members 152 is in the form of female engagement elements or sockets that receive the third engagement elements 174 of the bus-bar 170 that are in the form of male engagement elements or terminal. However, the present invention is not limited in any particular configuration, number and placement of the conductive members 152 and the third engagement elements 174 as far as the conductive members 152 engage with the complementary third engagement elements 174 formed on the corresponding bus-bars 170 to configure second dis-connectable electrical coupling between the electrical connector 150 and the corresponding bus-bars 170.

[0068] With such dis-connectable coupling between the bus-bar 170 and the electrical connector 150 on one side and the bus-bar 170 and the printed circuit board 140 on the other side, both the electrical connector 150 and the printed circuit board 140 are conveniently disc-connectable and hence replaceable in case of damage, thereby enhancing the serviceability of the inverter 130. Such configuration of the bus-bar 170 is adapted to configure dis-connectable coupling at ends thereof forms dis-connectable coupling with the printed circuit board 140 at one end and with the electrical connector 150 at the other end thereof. Accordingly, at least one of the printed circuit board 140 or the electrical connector 150 can be disassembled from inverter housing 132 by disconnecting either of the dis-connectable couplings 173, 175.

[0069] For assembly of the inverter 130, first the high voltage electrical connector 150 is mounted to outside of the inverter housing 132, particularly, the front head 132a by means of bolts so that at least a portion of the conductive member 152, particularly, the first end 152a of the conductive member 152 is received inside the inverter housing 132 through the first opening 136a. At least a portion of the conductive member 152 of the electrical connector 150, particularly, the first end 152a being received inside the inverter housing 132 engages with the third engagement elements 174 on the second side 170b of the bus-bar 170 to configure the second dis-connectable coupling 175. The bus-bar 170 is also mounted on the front head 132a, particularly, the end wall 134a by means of the first mounting bolt 137b passing through the first mounting hole 176b and the first mounting hole 137a aligned with respect to each other. The assembly of the electrical connector 150, the front head 132a and the bus-bar 170 is referred to as a first sub-assembly. The socket terminal 200 is secured to the printed circuit board 140 and the assembly of the socket terminal 200 and the printed circuit board 140 is referred to as a second sub-assembly. Finally, the socket terminal 200 of the second sub-assembly engages with the second engagement element 172 formed on the first end 170a of the bus-bar 170 to configure the first dis-connectable coupling 173 as the printed circuit board 140 is mounted on the front head 132a.

[0070] In accordance with one embodiment, the socket terminal 300 is over-molded by a second resin housing 306 as illustrated in FIG. 11 - FIG. 14. More specifically, the socket terminal 300 includes the second resin housing 306 formed over at least a portion thereof by plastic over-molding. The second resin housing 306 is formed by plastic over molding over at least a portion of the socket terminal 300 and facilitates mounting of the socket terminal 300 to the printed circuit board 140 and also facilitates positioning of the bus-bar 180 inside the front head 132a.

[0071] FIG. 13 and FIG. 14 illustrates different isometric views of the socket terminal 300. Although, the socket terminal 300 is structurally and functionally similar to the socket terminal 200 disclosed earlier in this document, however, the socket terminal 300 includes additional components such as for example, the second resin housing 306 that is not present in the socket terminal 200 . The socket terminal 300 also includes terminal ends 302 formed on a first end 300a and first engagement elements 304 formed at a second end 300b thereof similar to the socket terminal 200. However, for the sake of brevity of the present document, these elements are not described in detail. The second resin housing 306 is fixed on the printed circuit board 140. More specifically, the second resin housing 306 is formed by plastic over molding over the socket terminal 300 and includes a first flange portion 306a and a second flange portion 306c formed thereon. The first flange portion 306a is formed at the first end 300a of the socket terminal 300 and includes a first flange hole 306b for mounting the socket terminal 300 over the printed circuit board 140. In accordance with one embodiment, the socket terminal 300 is secured to the printed circuit board 140 by plastic riveting. The second flange portion 306c is formed at the second end 300b of the socket terminal 300 and includes a second flange hole 306d formed thereon.

[0072] Although, the bus-bar 180 corresponding to the socket terminal 300 is structurally and functionally similar to the bus-bar 170 corresponding to the socket terminal 200, wherein the bus-bar 170 is already described in the present document. Particularly, the bus-bar 180 also configures at least one dis-connectable coupling 183, 185 between the conductive member 152 of the electrical connector 150 and the first input portion 140a of the printed circuit board 140 and is formed with a first resin housing 186 formed with reinforcement rib 186a and a first mounting hole 186b similar to the bus-bar 170. However, the bus-bar 180 includes additional components such as for example positioning member 189 that is not present in the bus-bar 170. The positioning member 189 extends along the bus-bar 180 towards a first end 180a of the bus-bar 180 and is received in the second flange hole 306d formed on the socket terminal 300. Particularly, the second flange hole 306d formed on the second resin housing 306 receives the positioning member 189 extending from the second resin housing 306 formed on the bus-bar 180 for stably positioning the bus-bar 180 inside the front head 132a. More specifically, the positioning member 189 at the first end 180a of the bus-bar 180 is for positioning the first end 180a of the bus-bar 180 with respect to the printed circuit board 140 held inside the front head 132a and the first mounting bolt 137b passing through the first mounting hole 186b is for positioning a second end 180b of the bus-bar 180 with respect to the end wall 134a of the front head 132a. With such arrangement of the positioning member 189 and the first mounting bolt 137b passing through the first mounting hole 186b, the bus-bar 180 is securely held and positioned inside the front head 132a.

[0073] In accordance with another embodiment the electrical connector is a low voltage electrical connector 160. The corresponding bus-bar 190 in accordance with another embodiment for configuring electrical coupling and mechanical connection between the low voltage connector 160 and the printed circuit board 140 as illustrated in FIG. 16 of the accompanying drawings. The low voltage electrical connector 160 supply low voltage electrical power to the printed circuit board 140. Similar to the high voltage electrical connector 150, the low voltage electrical connector 160 also includes conductive member 162, wherein at least a portion of the conductive member 162, particularly, a first end 162a of the conductive member 162 is received inside the inverter housing 132 via a second opening 136b formed on the end wall 134a. The bus-bar 190 comprises first lead frames 192 and second lead frames 194. The bus-bar 190 further comprises a first resin housing 196 formed with reinforcement element 196a to provide reinforcement to the bus-bar 190. The first resin housing 196 further includes a first mounting hole 196b aligned to the corresponding first mounting hole 137a formed on the front head 132a for passage of the first mounting bolt 137b there through. The first lead frames 192 are adapted to be soldered to a second input portion 140b of the printed circuit board 140 and the second lead frames 194 are adapted to dis-connectably engage with the first end 162a of the conductive member 162 to form the dis-connectable coupling there with. With such arrangement, there is at least one dis-connectable coupling between the conductive member 162 and the second input portion 140b of the printed circuit board 140. More specifically, the first lead frames 192 forms fixed connection with the second input portion 140b of the printed circuit board 140 by soldering, whereas the second lead frames 194 forms dis-connectable coupling 195 with the first end 162a of the conductive member 162.

[0074] 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.List of Reference Numerals

[0075] Reference Description numeral 100 electric machine 110 machine or compressor unit 110a compressor housing 120 electric motor 120a motor housing 130 inverter 132 inverter housing 132a front head 132b cover 134a end wall of the front head 136a first opening on the end wall 137 first column on the end wall 137a first mounting hole on the first column 137b first mounting bolt 139 second column 139a second mounting hole on the second column 139b second mounting bolt 140 printed circuit board (PCB) 140a first input portion 140b second input portion 150 high voltage electrical connector 152 first conductive member of the high voltage electrical connector 152a first end of the first conductive member 160 low voltage electrical connector 162 second conductive member of the low voltage electrical connector 162a first end of the second conductive member 170 bus-bar according to a first embodiment 170a first end of the bus-bar of the first embodiment 170b second end of the first bus-bar of the first embodiment 172 second engagement element of the bus-bar of first embodiment 173 first dis-connectable connection formed by bus-bar of first embodiment 174 third engagement element of the bus-bar of the first embodiment 174a spring elements defining the third engagement element 175 second dis-connectable connection formed by bus-bar of first embodiment 176 first resin housing for the bus-bar of the first embodiment 176a reinforcement rib on first resin housing of the bus-bar of first embodiment 176b first mounting hole on first resin housing of bus-bar of first embodiment 200 socket terminal in accordance with a first embodiment 200a first end of the socket terminal of the first embodiment 200b second end of the socket terminal of the first embodiment 202 terminal end of the socket terminal of the first embodiment 204 first engagement element of the socket terminal of the first embodiment 204a spring elements defining the first engagement element 180 bus-bar according to a second embodiment 180a first end of the bus-bar of the second embodiment 180b second end of the first bus-bar of the second embodiment 182 second engagement element of bus-bar of the second embodiment 183 first dis-connectable connection formed by bus-bar of second embodiment 184 third engagement element of the bus-bar of second embodiment 185 second dis-connectable connection formed by bus-bar of second embodiment 186 first resin housing for the bus-bar of second embodiment 186a reinforcement rib on first resin housing of bus-bar of second embodiment 186b first mounting hole on first resin housing of bus-bar of second embodiment 300 socket terminal in accordance with a second embodiment 300a first end of the socket terminal of the second embodiment 300b second end of the socket terminal of the second embodiment 302 terminal end of the socket terminal of the second embodiment 304 first engagement element of socket terminal of the second embodiment 306 second resin housing for the socket terminal of the second embodiment 306a first flange portion for the second resin housing 306b first flange hole formed on the first flange portion 306c second flange portion for the second resin housing 306d second flange hole formed on the second flange portion 190 first bus-bar according to a third embodiment 190a first end of the bus-bar of the third embodiment 190b second end of the first bus-bar of the third embodiment 192 first set of lead frames of bus-bar of the third embodiment 193 fixed connection formed between bus-bar of third embodiment and PCB 194 second set of lead frames of bus-bar of the third embodiment 196 first resin housing for the bus-bar of third embodiment 196a reinforcement rib on first resin housing of bus-bar of third embodiment 196b first mounting hole on first resin housing of bus-bar of third embodiment

Claims

1. An electric machine (100) comprising: a machine (110); an electric motor (120) to drive the machine (110); an inverter (130) received and held in an inverter housing (132) and adapted to process and regulate electrical power being supplied to the electric motor (120) from an external power source, the inverter (130) comprising a printed circuit board (140); an electrical connector (150, 160) mounted on an end wall (134a) of the inverter housing (132), the electrical connector (150, 160) comprising a conductive member (152, 162) penetrating through the end wall (134a), wherein a first end (152a, 162a) of the conductive member (152, 162) is electrically connected to an input portion (140a, 140b) of a printed circuit board (140) via a bus-bar (170, 180, 190), characterized in that there is at least one dis-connectable coupling (173, 175, 183, 185, 195) between the conductive member (152, 162) and the input portion (140a, 140b).

2. The electric machine (100) according to claim 1, further comprising a socket terminal (200, 300) mounted on and electrically coupled to the input portion (140a) of the printed circuit board (140), wherein a first end (200a, 300a) of the socket terminal (200, 300) is adapted to be fixed to the first input portion (140a), and a second end (200b, 300b) of the socket terminal (200, 300) is provided with a first engagement element (204, 304), a first end (170a, 180a) of the bus-bar (170, 180) is connected to the first engagement element (204, 304) of the socket terminal (200, 300) to form the first dis-connectable coupling (173, 183).

3. The electric machine (100) according to claim 2, wherein a first end (170a, 180a) of the bus-bar (170, 180) is configured with a second engagement element (172, 182) adapted to be directly engaging with and electrically coupled to the socket terminal (200, 300).

4. The electric machine (100) according to claim 1, wherein a second end (170b, 180b) of the bus-bar (170, 180) is provided with a third engagement element (174, 184), the first end (152a, 162a) of the conductive member (152, 162) is connected to and electrically coupled to the third engagement element (174, 184) of the bus-bar (170, 180) to form the dis-connectable coupling (175, 185).

5. The electric machine (100) according to claim 2 or 4, wherein position (A) of the conductive member (152, 162) of the electrical connector (150, 160) mounted on the end wall (134a) of the inverter housing (132) is offset with position (B) of the input portion (140a, 140b) of the printed circuit board (140), the bus-bar (170, 180) has a bended portion (178, 188) between the first end (170a, 180a) and the second end (170b,180b) so as to adapt the offset positions (A, B).

6. The electric machine (100) according to claim 5, wherein portions of the bus-bar (170, 180) on opposite sides of the bended portion (178, 188) are at an angle with respect to each other.

7. The electric machine (100) according to claim 5, wherein the bus-bar (170, 180) is over-molded by a first resin housing (176, 186).

8. The electric machine (100) according to claim 7, wherein the first resin housing (176, 186) is formed with reinforcement ribs (176a, 186a).

9. The electric machine (100) according to claim 7, wherein the first resin housing (176, 186) of the bus-bar (170, 180) is fixed on the inverter housing (132).

10. The electric machine (100) according to claim 7, wherein the first resin housing (176, 186) comprises at least one first mounting hole (176b, 186b) aligned to corresponding hole (137a) formed on a front head (132a) for passage of mounting bolt (137b) there through.

11. The electric machine (100) according to claim 10, wherein the mounting bolt (137b) is accessible even when the printed circuit board (140) is mounted on a front head (132a).

12. The electric machine (100) according to claim 10, wherein the printed circuit board (140) comprises an access hole (142) formed thereon and adapted to provide access to the mounting bolt (137b) when the printed circuit board (140) is securely mounted to the inverter housing (132).

13. The electric machine (100) according to claim 2, wherein the socket terminal (300) is over-molded by a second resin housing (306) and the second resin housing (306) is fixed on the printed circuit board (140).

14. The electric machine (100) according to claim 2, wherein the first end (200a, 300a) of the socket terminal (200, 300) comprises terminal ends (202, 302) adapted to be secured to and electrically coupled to the first input portion (140a) of the printed circuit board (140), the terminal end (202, 302) further being in electrical contact with the first engagement elements (204, 304).

15. The electric machine (100) according to claim 7, wherein the first resin housing (186) further comprises a positioning member (189) extending along the bus-bar (180) towards the first end (180a) and adapted to be received in a flanged hole (306d) formed on the socket terminal (300).

16. The electric machine (100) according to claim 1, wherein substantial portion of the electrical connector (150, 160) is disposed outside the inverter housing (132).

17. The electric machine (100) according to claim 1, wherein the bus-bar (190) comprises first lead frames (192) and second lead frames (194), the first lead frames (192) adapted to be soldered to the second input portion (140b) of the printed circuit board (140) and the second lead frames (194) adapted to engage with the first end (152a, 162a) of the conductive member (152, 162) to form the dis-connectable coupling (195) there with.

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