Electrically driven compressor

Abstract

Electrically driven compressor (1) with a first metal housing (2) in which an electric motor (6) is received, a second metal housing (3) in which a compression mechanism (9) is received, which is driven by the electric motor (6), and an annular sealing ring (16) which is inserted between joining surfaces of the first and second housings (1, 2), characterized in that the sealing ring (16) has an electrical connection section (109, 111) with which the first and the second housings (1, 2) can be electrically connected, wherein the sealing ring (16) is formed with a metal carrier (16a) and a rubber layer (16b) which covers both of its surfaces, and the electrical connection section (109, 111) is a metal carrier exposure section (109, 111) which is formed on each of the two surfaces of the sealing ring (16) and which exposes the metal carrier (16a) by removing a section exposes the rubber layer (16b),wherein the sealing ring (16) has an annular bead (101, 102) on its inner edge side and its outer edge side, and through holes (107) for bolts between the beaded edges (101, 102) to connect the first and second housings (1, 2) together, and the metal support exposure section (109, 111) is formed between the beaded edges (101, 102), wherein a convex surface (105) is located between the beaded edges (101, 102) of one surface of the sealing ring (16) and a concave surface (106) is located between the beaded edges (101, 102) of the other surface, wherein the metal support exposure section (109) of one surface of the sealing ring (16) is formed at an edge section of a through hole (107) of the convex surface (105), wherein the sealing ring (16) has a convex section (110) that projects from the concave surface, and the metal support exposure section (109, 111) of the other surface of the sealing ring (16) is formed on the convex section (110).

Description

TECHNICAL AREA

[0001] The present invention relates to an electrically driven compressor in which an electric motor and a compression mechanism are housed in a casing, and in particular to an electrically driven compressor of a type in which the casing is divided in the axial direction of the electric motor and joined together via a sealing ring. STATE OF THE ART

[0002] An electrically driven compressor of the inverter type is known from patent document 1. This electrically driven compressor has a housing (main body housing) containing an electric motor and a compression mechanism, an inverter housing open at one end containing an inverter for driving the electric motor, and a lid-shaped inverter cover to close the opening of the inverter housing. All these elements are made of metal. A sealing ring is used between the annular joining surfaces of the inverter housing and the inverter cover to act as a sealing element. However, the sealing ring is insulating due to a rubber coating on its surface. Therefore, it is necessary to electrically connect the inverter housing and the inverter cover. For this purpose, a convex section is provided on one of the annular joining surfaces, at a position located inwards relative to the sealing ring, to directly connect the two elements. LIST OF REFERENCE DOCUMENTS PATENT DOCUMENTS

[0003] PATENT DOCUMENT 1: Unexamined Japanese patent application no. 2015-017577 BRIEF DESCRIPTION OF THE INVENTIONAL TASK OF THE INVENTION

[0004] As an enclosure structure for the electrically driven compressor, the housing that accommodates the electric motor and the compression mechanism is sometimes divided into a first housing that accommodates the electric motor and a second housing that accommodates the compression mechanism, with the first and second housings being joined together via a sealing ring. With an electrically driven compressor with such an enclosure structure, there is a risk that a potential difference will occur between the first enclosure and the second enclosure, and that the current flow will cause discomfort to a person who touches the enclosure structure at the delivery point of the product. Therefore, it is required to equalize the potential of the first enclosure and the second enclosure. As a measure for potential equalization, it is conceivable, as with the measure from patent document 1, to provide a convex section as an electrical connection section on the annular joining surface of the first or second housing at a position which is inside with respect to the sealing ring. However, if the width of the annular joining surfaces (thickness of the housing) cannot be large, a measure like the one described in patent document 1 is difficult. With regard to the inverter housing and the inverter cover, it is conceivable to provide a projecting section extending from the inner bottom section of the inverter housing and to position the front end of the projecting section against the inner surface of the inverter cover in order to establish an electrical connection (see patent application no. 2017-109158 of the applicant). However, since the electric motor is located in the first housing and the compression mechanism in the second housing, it is difficult to provide the electrical connection section inside the housing. The present invention was made in view of the aforementioned circumstances, and its objective is to achieve a potential equalization between the first housing in which the electric motor is housed and the second housing in which the compression mechanism is housed, by means of a comparatively simple structure. SOLUTION OF THE TASKS

[0005] An electrically driven compressor according to the present invention comprises a first metal housing in which an electric motor is received, a second metal housing in which a compression mechanism is received and driven by the electric motor, and an annular sealing ring inserted between the joining surfaces of the first and second housings. It is characterized in that the sealing ring has an electrical connection section by which the first and second housings can be electrically connected. The sealing ring is formed with a metal carrier and a rubber layer covering both of its surfaces, and the electrical connection section can be a metal carrier exposure section formed on each of the two surfaces of the sealing ring, exposing the metal carrier by removing a section of the rubber layer. The sealing ring may have an annular bead on its inner and outer edge sides, and through holes for bolts between the beads to connect the first and second housings, and the metal support exposure section may be formed between the beads. EFFECTS OF THE INVENTION

[0006] By providing the electrical connection section on the sealing ring itself (on a circumferential section and a lateral section) according to the present invention, potential equalization of the first and second housings can be achieved without increasing the width of the joining surfaces. Since the metal support exposure section is provided on the sealing ring, a particularly simple design is possible. Positioning it between the ridges prevents any impairment of the sealing performance. List of characters

[0007] They show: Fig. 1 a vertical sectional view of an electrically driven compressor according to an embodiment of the present invention; Fig. 2 a front view of a sealing ring corresponding to a view at arrows AA from Fig. 1; Fig. 3 a rear view of the sealing ring; Fig. 4 an enlarged view of section B from Fig. 2; Fig. 5 a section view along line CC from Fig. 4; and Fig. 6 a section view along line DD from Fig. 4. DESCRIPTION OF THE EXECUTION FORMS

[0008] One embodiment of the present invention is described in detail below. Fig. Figure 1 shows a vertical sectional view of an electrically driven compressor according to an embodiment of the present invention. The electrically driven compressor of the present embodiment is of a horizontally installed design (with a horizontal compressor center axis), is integrated into the refrigerant circuit of a vehicle air conditioning system, draws in refrigerant, compresses it, and discharges it. Lubricating oil is added to the refrigerant. A housing of the electrically driven compressor 1 The compressor is subdivided multiple times in the direction of the compressor's central axis and is formed by a front housing (first housing) 2, a middle housing (second housing) 3, and a rear housing (third housing) 4. These are joined in one piece as described below. The front case 2 is essentially cylindrical and has a partition wall in the middle in the axial direction 5on. On the right side of the partition in the drawing 5 of the front case 2 An electric motor mounting space is formed in which an electric motor 6 has been recorded. The electric motor 6 is equipped with a rotating shaft 6a , which are rotatable on a central section in the front housing 2 is mounted on a rotor 6b with a permanent magnet that rotates around the shaft 6a is attached around it, and a stator 6c formed with electromagnetic windings, which is located on the inner wall of the front housing 2 is held fixed and the rotor 6b surrounds. On the left side of the partition in the drawing 5 of the front case 2 An inverter chamber is formed in which an inverter (drive circuit for the electric motor) 7 is included. The inverter 7 controls the power supply of the electric motor6 , by converting direct current from an external power supply source into alternating current. The inverter 7 It includes in particular a capacitor for smoothing the DC voltage from the external power supply source, a power module that uses PWM control (control in which a voltage with a modulated pulse width is generated to seemingly achieve a sine wave at a constant frequency) to convert the DC voltage from the capacitor into AC voltage and apply it to the coil on the stator side. 6c of the electric motor 6 installs, and a power module control circuit that uses the power module to drive the electric motor based on a control signal from an external air conditioner. 6 controls. An opening section of the inverter mounting compartment of the front housing 2 (In other words, an opening section of the inverter housing) is covered by a lid-shaped inverter cover.8 hermetically sealed. The middle case 3 It is essentially cylindrical, and inside it is a motor powered by an electric motor. 6 driven compression mechanism 9 recorded. The compression mechanism 9 The present embodiment features a compression mechanism of the spiral type and comprises a fixed spiral element. 10 , a movable spiral element 11 and a crank mechanism section 12 . In the fixed spiral element 10 and the movable spiral element 11 are spiral paths 10b , 11b one piece on each end plate 10a , 11a formed and arranged facing each other in the direction of the central axis. The movable spiral element 11 is driven by the rotating shaft 6a of the electric motor 6 by means of the crank mechanism section 12moved in a circular path around the compressor's central axis, while its rotation is prevented. Fluid pockets located between the spiral flute 10b of the fixed spiral element 10 and the spiral path 11b of the movable spiral element 11 The fluids formed shift from the outer side to the inner side, reducing their volume and thus compressing the fluid (namely refrigerant gas) absorbed into the fluid pockets on the outer side. On the outer wall of the front casing 2 or the middle case 3 An intake opening (not shown) for refrigerant is provided. The refrigerant drawn in through the intake opening flows into the front housing. 2 It lubricates and cools the electric motor. 6 (and cools via the partition wall) 5 the inverter 7 ), then flows into the middle housing 3, is taken up by the fluid pockets on the outer circumferential side of the spiral passages 10b, 11b and subjected to compaction. The compressed refrigerant is discharged through a discharge hole. 13 with a one-way valve located in the middle section of the end plate 10a of the fixed spiral element 10 It is intended to be drained. The rear casing 4 is in relation to the middle case 3 arranged like a lid and forms between itself and the end plate 10a of the fixed spiral element 10 , located on the middle case 3 is fixed, an output chamber 14 for the refrigerant. This is achieved by means of the compression mechanism 9 Compressed refrigerant is thus extracted from the outlet hole 13 into the issuing chamber 14 inside the rear case 4 discharged and from there via a channel on the outer wall of the rear housing 4intended dispensing opening 15 directed outwards. The following is a description of the connection structure and the sealing structure of the front housing. 2 , of the middle case 3 and the rear case 4 . Between the joining surfaces on the outer circumferential side of the front housing 2 and the middle case 3 , which are joined together, form a ring-shaped sealing ring. 16 It is used. Likewise, it is used between the joining surfaces on the outer circumference of the middle housing. 3 (and the end plate 10a ) and the rear case 4 , which are joined together, a ring-shaped sealing ring 17 used. The sealing rings 16 , 17are designed, as described below, such that both sides of a metal carrier are covered with a layer of rubber, and are insulating with respect to the assembled elements. The front case 2 , the middle case 3 and the rear case 4 are formed by several (for example six) bolts arranged at suitable intervals in the circumferential direction 18 tied together. The bolts 18 run parallel to the compressor's central axis from the side of the rear casing 4 through the rear casing 4 and the middle case 3 and are in the front case 2 screwed. Therefore, the rear case 4 and in the middle case 3 Bolt holes were formed. Also at the sealing rings. 17 , 16 Bolt holes have been formed on the front housing. 2 are screw holes2s formed, into which the bolts 18 are screwed together. The seating surface of the head section of the bolts 18 is on the rear case 4 locked, the shaft section runs through the bolt holes of the rear housing. 4 , of the sealing ring 17 , of the middle case 3 and the sealing ring 16 and the threaded section at the front end is in the screw holes 2s of the front case 2 screwed. So, although the front case 2 and the rear case 4 They are not in direct contact with each other, they are connected by the bolts 18 electrically connected. The reason for this is that the head section of the bolts 18 with sufficient contact pressure with the rear housing 4 is in contact and the threaded section of the bolts 18 with sufficient contact pressure with the screw holes2s of the front case 2 is in contact. In contrast, the front casing 2 and the middle case 3 not electrically connected. By arranging the insulating sealing ring. 16 In between, they do not touch each other directly, and the bolts 18 run with play through the bolt holes of the middle housing 3 . In the present embodiment, the sealing ring 16 between the front case 2 and the middle case 3 A potential equalization has been achieved. The detailed structure of the sealing ring 16 and the measures for potential equalization are implemented with reference to Fig. 2 to Fig. 6 described in detail. Fig. Figure 2 shows a front view of a sealing ring. 16 according to a view of the arrows AA from Fig. 1, Fig. Figure 3 shows a rear view of the sealing ring. 16 , Fig. Figure 4 shows an enlarged view of section B. Fig. 2, Fig. 5 shows a section view along line CC from Fig. 4 and Fig. Figure 6 shows a section view along line DD. Fig. 4. To form the sealing ring 16 A metal sheet coated with a layer of rubber is punched out in a ring shape, while a bead is created by machining at the same time as the punching or before or after the punching. Therefore, the sealing ring 16 as in Fig. 5 (and Fig. 6) shown with a metal support 16a and a rubber layer covering both surfaces 16b formed. The thickness of the metal support 16a is approximately 0.2 mm and the thickness of the rubber layer 16b Each is approximately 0.1 mm. The sealing ring16 It has a ring-shaped ridge (half-ridge) on both its inner and outer edge sections. 101 , 102 on.

[0009] The inside of the ridge 101 on the inner edge and the outer edge of the ridge 102 Seating surfaces (reference surfaces) form on the outer edge. 103 , 104 . The area between the bulge 101 on the inner edge and the ridge 102 When viewed from the front, the outer edge has a convex surface (convex flat surface). 105 and when viewed from behind, a concave surface (concave flat surface) 106. When assembling the front housing 2 , of the middle case 3 and the rear case 4 Generally, the front case will be 2 clamped with its joining surface facing upwards in a clamping device, and the sealing ring 16 , the middle case 3, the sealing ring 17 and the rear case 4 They are arranged on it one after the other. So that the sealing ring... 16 Because it fits well, it is therefore positioned with the seat facing downwards. The seating surfaces are located there 103 , 104 (and the concave surface 106 ) of the sealing ring 16 on the side of the front case 2 and the convex surface 105 of the sealing ring 16 It lies on the side of the middle case. 3 . The sealing ring also features 16 between the bulge 101 on the inner edge and the ridge 102 Six bolt holes on the outer edge 107 and two positioning holes 108 on. At the bolt holes 107 As already mentioned, these are through holes for the bolts. 18 to connect the rear case 4 , of the middle case3 and the front casing 2 . The positioning holes 108 These are holes that are used during assembly to position the front housing 2 installed sealing ring 16 They serve this purpose. For this positioning, they spring onto the joining surface of the front housing. 2 Positioning pins 19 (see Fig. 1) before. At the joining surface of the middle housing 3 are guide holes 20 formed (see Fig. 1), into which the positioning pins 19 be introduced. The shape and structure of the sealing ring described above 16 The same applies to the sealing ring. 17 . The sealing ring 16 For the purpose of potential equalization, it has the following special form and structure. Between the bulge 101 on the inner edge and the ridge 102 on the outer edge of the sealing ring 16on the side of the convex surface 105 is arranged at the edge section of any one of the bolt through holes 107 an electrical connection section 109 formed (see Fig. 2, Fig. 4 and Fig. 6). The electrical connection section 109 This is a metal support exposure section where the rubber layer has been removed at this point (for example by grinding) to expose the metal support. Between the bulge 101 on the inner edge and the ridge 102 on the outer edge of the sealing ring 16 on the side of the concave surface 106 is a round, projecting, convex section 110 formed (see Fig. 3 and Fig. 6) The convex section 110 Viewed from behind, it is a convex section, and viewed from the front, a concave section. 110' . At the edge of the round convex section110 between the bulge 101 on the inner edge and the ridge 102 on the outer edge of the sealing ring 16 on the side of the concave surface 106 is an electrical connection section 111 formed (see Fig. 3 and Fig. 6). The electrical connection section 111 This is a metal support exposure section where the rubber layer has been removed at this point (for example by grinding) to expose the metal support. The convex section 110 is adjacent to the bolt hole 107 provided for, at which the electrical connection section 109 is formed. For example, the distance between the bolt through-hole is 107 , where the electrical connection section 109 is formed, and the convex section 110 shorter in the circumferential direction than the distance between the other bolt holes107 and the convex section 110 in the circumferential direction. This results in the electrical connection section (metal support exposure section) 109 on one surface and the electrical connection section (metal support exposure section) 111 on the other surface of the sealing ring 16 in the circumferential direction of the sealing ring 16 adjacent. By using the sealing ring 16 This structure achieves the following effect. The sealing ring 16 is achieved by connecting the front housing 2 and the middle case 3 at the corner sections of the bulges 101 , 102 Squeezed. This ensures a secure seal between the joining surfaces of the front housing. 2 and the middle case 3 . The seal between the joining surfaces of the front housing 2 and the middle case3 This is done by working on the corner sections of the bulges 101 , 102 of the sealing ring 16 A surface pressure is created, which is why the area between the ridge 101 on the inner edge and the ridge 102 The seal is not affected at the outer edge. Therefore, a section will be 109 the area between the bulge 101 on the inner edge and the ridge 102 The rubber layer was removed from the outer edge, exposing the metal support, and also on one section 111 The rubber layer was removed from the other surface, exposing the metal support. By creating the metal support exposure sections on both surfaces in this way 109 , 111 The sealing ring is provided for 16 compressed by the axial pulling force, which is why the front housing 2 and the middle case 3 at the metal beam exposure sections 109 ,111 to come into contact with metal, thus ensuring potential equalization. This includes the metal beam exposure section. 109 on the side of the convex surface 105 between the bulges 101 , 102 of the sealing ring 16 at the edge section of the bolt through hole 107 provided for. Since the surface pressure on this part is reliably controlled by the axial force of the bolts. 18 As the temperature increases, the sealing ring can be easily compressed, and the contact pressure is high. Therefore, a reliable electrical connection can be achieved. On the side of the concave surface 106 between the bulges 101 , 102 of the sealing ring 16 is the convex section 110 provided for, at the edge section of which the metal support exposure section 111This is intended. This increases the surface pressure on this part, which is why a reliable electrical connection can be achieved. The metal beam exposure sections 109 , 111 The two surfaces are spaced apart by a certain amount in the circumferential direction, but adjacent in the circumferential direction, which is why the front housing 2 and the middle case 3 over the metal beam 16a They can be connected with a relatively small distance between them, so that their electrical connection is not affected. According to the present embodiment, the sealing ring has 16 an electrical connection section with which the first and second housings (the front housing) 2 and the middle case 3) can be connected, which is why a potential equalization of the first and second housings can be achieved without increasing the width of the joining surfaces. The sealing ring is also 16 according to the present embodiment with the metal support 16a and the rubber layer 16b formed, covering both of its surfaces, and the electrical connection section consists of the metal support exposure sections. 109 , 111 , which are located on the two surfaces of the sealing ring 16 are formed and the metal support 16a by removing a section of the rubber layer 16b Expose. Therefore, a version using an existing sealing ring is easily possible. According to the present embodiment, the sealing ring has 16 on its inner and outer edges, the ring-shaped ridges 101 , 102 and between the bulges 101, 102 the through holes 107 for the bolts 18 up, and the metal beam exposure sections 109 , 111 are between the bulges 101 , 102 formed. Consequently, an impairment of the sealing performance can be avoided. According to the present embodiment, there is a space between the ridges. 101 , 102 a surface of the sealing ring 16 the convex surface 105 and between the bulges 101 , 102 the other surface the concave surface 106 before, whereby the metal support exposure section 109 one surface of the sealing ring 16 at the edge of a through hole 107 the convex surface 105 is formed. In the area of ​​the through-hole. 107 The axial tightening force and contact pressure are high, which is why a reliable electrical connection can be achieved. The sealing ring also features 16 according to the present embodiment, the convex section 110 on, which is from the concave surface 106 protrudes, and the metal beam exposure section 111 the other surface of the sealing ring 16 is on the convex section 110 formed. Because in this way the contact pressure is also on the side of the concave surface. 106 By increasing the voltage, a reliable electrical connection can be achieved. According to the present embodiment, the metal support exposure section 109 on one surface and the metal beam exposure section 111 on the other surface of the sealing ring 16 in the circumferential direction of the sealing ring 16 adjacent. This allows the connection distance to be adjusted when electrically connecting via the metal support. 16a be shortened. Returning to Fig.1. The potential equalization measure of the inverter housing section of the front housing will be 2 and the inverter cover 8 described. The inverter housing section of the front housing 2 and the inverter cover 8 are protected by an insulating sealing ring 21 joined and fixed. This involves a section of the inner bottom of the inverter housing. 2 a prominent promontory section is provided, and the leading end of the promontory section 22 is attached to the inner surface of the inverter cover 8 This was done to establish an electrical connection. In the process, the inverter cover deformed. 8 to a certain extent. The description above only refers to the sealing ring. 16 between the first housing (front housing) 2 ) and the second housing (middle housing) 3) an electrical connection section is provided, but it can also be connected to the sealing ring 17 between the second housing (middle housing) 3 ) and the third housing (rear housing) 4 ) an electrical connection section must be provided. Furthermore, the embodiment described above is merely an example to illustrate the present invention, and the present invention may, in addition to what is directly demonstrated by the described embodiment, include various modifications and alterations within the scope of the claims that are apparent to a person skilled in the art. For example, an existing sealing ring was modified in the description above, but a sealing ring with an electrical connection section can also be newly manufactured. Reference symbol list 1 electrically driven compressor 2 front case (first case) 2s screw hole 3 medium case (second case) 4 rear case (third case) 5 Partition wall 6 electric motor 6a Rotary shaft 6b Rotor 6c Stator 7 Inverter 8 Inverter cover 9. Compression mechanism 10 fixed spiral element 10a End plate 10b spiral path 11 movable spiral element 11 a End plate 11b Spiral path 12 Crank mechanism section 13 Output hole 14 Issuing Chamber 15 Issue opening 16 sealing rings 16a Metal beam 16b Rubber layer 17 sealing ring 18 bolts 19 Positioning pin 20 guide holes 21 sealing ring 22 Projection section from the inner bottom section of the inverter housing 101, 102 bulge 103, 104 Seat area (reference area) 105 convex surface (convex flat surface) 106 concave surface (concave flat surface) 107 Bolt through hole 108 Positioning hole 109 Electrical connection section (metal support exposure section) 110 lead section 111 Electrical connection section (metal support exposure section) QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] JP 2015017577

[0003]

Claims

[1] Electrically driven compressor comprising a first metal housing containing an electric motor, a second metal housing containing a compression mechanism driven by the electric motor, and an annular sealing ring inserted between the joining surfaces of the first and second housings, characterized by that the sealing ring has an electrical connection section with which the first and second housings can be electrically connected. [2] Electrically driven compressor according to claim 1, characterized by , that the sealing ring is formed with a metal support and a rubber layer covering both of its surfaces, and the electrical connection section is a metal support exposure section formed on each of the two surfaces of the sealing ring, exposing the metal support by removing a section of the rubber layer. [3] Electrically driven compressor according to claim 2, characterized by , that the sealing ring has an annular bead on its inner edge side and its outer edge side, and through holes for bolts between the beads to connect the first and second housings, and the metal support exposure section is formed between the beads. [4] Electrically driven compressor according to claim 3, characterized by , that between the ridges of one surface of the sealing ring there is a convex surface and between the ridges of the other surface there is a concave surface, wherein the metal support exposure section of one surface of the sealing ring is formed at an edge section of a through hole of the convex surface. [5] Electrically driven compressor according to claim 4, characterized by, that the sealing ring has a convex section that protrudes from the concave surface, and the metal support exposure section of the other surface of the sealing ring is formed on the convex section. [6] Electrically driven compressor according to claim 5, characterized by , that the metal support exposure section of one surface and the metal support exposure section of the other surface of the sealing ring adjoin each other in the circumferential direction of the sealing ring.