Low-profile connection assembly with minimal contact

Abstract

The invention relates to a connecting assembly for connecting two elements (10a, 10b) including flanges (12a, 12b) configured to be connected to each other, the flanges (12a, 12b) including inner sides configured to abut to each other and outer sides facing away from each other. The connecting assembly includes a metal band (16) configured to be strapped around the outer circumference of the flanges (12a, 12b) and a tightening device (18) for tightening the metal band (16). It is proposed that the metal band (16) includes a plurality of longitudinal slots (20) separated by connecting portions (22) in a longitudinal direction, wherein the longitudinal slots (20) are laterally delimited by web portions (20a, 20b) of the metal band (16) and wherein the web portions (20a, 20b) are configured to abut to the outer sides of the flanges (12a, 12b) to thereby connect the flanges (12a, 12b) when the metal band (16) is being tightened, wherein at least one of the longitudinal slots (20) is formed as a longitudinal cut and two transverse cuts at the ends of the longitudinal slot, wherein tab portions delimited by the longitudinal cut and two transverse cuts are bent inward or outward.

Description

[0001] Low-profile connection assembly with minimal contact

[0002] The invention relates to a connection assembly according to the preamble of claim 1 .

[0003] It is well-known to connect flanges of machine elements such as housing parts or tubes with nuts and bolts . As this requires multiple nuts and bolts and alignment of the holes in the flanges , the assembly of such a connection is burdensome and not flexible ion that a relative position of the elements in is predetermined by the alignment of the holes .

[0004] It has further been proposed to connect flanges using V-Clamps . The document US2017184238A1 discloses a connecting device between a turbine housing of an exhaust turbocharger and an exhaust manifold housing of an internal combustion engine . The turbine housing and the exhaust manifold housing are kept in position via a band clamp which acts with first and second limbs , which are oriented in a V shaped manner in cross section and are connected via a web , on supporting devices , which are attached to outer circumferences of the turbine housing and of the exhaust manifold housing .

[0005] While the use of V-Clamps with a single tightening device greatly facilitates the assembly and is more flexible with regard to positioning in the circumferential direction, this solution still has some drawbacks in that the tightening device requires assembly space , which may not be available and in that the contact between the clamping band and the elements being connected may entail galvanic corrosion if the band and the elements are made of different metal .

[0006] Moreover, some applications such as compressors for compressing oxygen and / or hydrogen in a fuel cell electric vehicle ( FCEV) require high safety standards in terms of the pull-off force , i . e . the minimum axial force required to disconnect the elements . The latter applies in particular to shock-like forces which may occur when a rotor is ruptures or in the event of ac- cidents . Experiments have shown that pull-off forces as high as 60 kN may be required in the context of air compressors of FCEVs .

[0007] The invention seeks to provide a connection assembly solving the above problems and drawbacks of connection assemblies according to the prior art .

[0008] The problem is solved by a device having the features of claim 1 . Advantageous embodiments of the invention are defined in the dependent claims .

[0009] The invention relates to a connecting assembly for connecting two elements including flanges configured to be connected to each other, the flanges including inner sides configured to abut to each other and outer sides facing away from each other . The connecting assembly includes a metal band configured to be strapped around the outer circumference of the flanges and a tightening device for tightening the metal band .

[0010] It is proposed that the metal band includes a plurality of longitudinal slots separated by connecting portions in a longitudinal direction, wherein the longitudinal slots are laterally delimited by web portions of the metal band and wherein the web portions are configured to abut to the outer sides of the flanges to thereby connect the flanges when the metal band is being tightened . By this design of the band, it is possible to limit the contact surface between the metal band and the elements being connected and thereby reduce galvanic corrosion . Meanwhile , the clamping assembly has a very low profile , is adaptable to different sizes and shapes of the flanges , including noncircular shapes . Moreover , the assembly is easy, and a low number of parts is required .

[0011] According to an advantageous embodiment of the invention, the elements are aluminium housing elements , and the metal band is a steel band . In this combination, the advantages of reduced gal- vanic corrosion due to reduced contact surface can exploit their full potential .

[0012] It is further proposed the metal band is pre-shaped in an essentially polygonal shape , wherein the longitudinal slots are provided in straight portions of the polygonal shape and the connecting portions are provided in corner portions of the polygonal shape . This facilitates the assembly and may provide additional longitudinal elasticity depending on the shape of the corner portions .

[0013] According to an advantageous embodiment of the invention, the slots are substantially rectangular and are provided with radiuses on the edge portions thereof . This reduces influence of notches created during cutting process and makes the connection more robust against tear .

[0014] In a further advantageous embodiment of the invention, at least one of the longitudinal slots is formed as a longitudinal cut and two transverse cuts at the ends of the longitudinal slot , wherein tab portions delimited by the longitudinal cut and two transverse cuts are bent in-ward or outward .

[0015] It is further proposed a root portion of the outer sides of the flanges includes a radius or a slope .

[0016] The inventors further propose the inner side of at least one of the flanges , preferably both of the flanges , includes a groove accommodating an O-ring .

[0017] Preferably, the metal band includes from 4 to 7 slots .

[0018] A further aspect of the invention relates to an air compressor in including two housing parts and a connecting assembly as described above , wherein the two housing parts are the two elements including flanges connected by the connecting assembly . Further features and advantages will be apparent from the following description of the embodiments and figures . The entire description, claims and figures disclose features of the invention in specific embodiments and combinations . The person s killed in the art will also consider the features individually and combine them into further combinations or sub-combinations to adapt the invention, as defined in the claims , to his needs or to specific fields of application .

[0019] The figures illustrate the following :

[0020] Fig . 1 illustrates a connecting assembly according to a first embodiment of the invention;

[0021] Fig . 2 is a partial section of the flanges of housing parts of an air compressor to be connected with the connecting assembly according the invention;

[0022] Fig . 3 illustrates one of the slots according to a first embodiment of the invention;

[0023] Fig . 5 is a sectional view of the connection assembly according to a second embodiment of the invention; and Fig . 6 is a sectional view of the connection assembly according to a third second embodiment of the invention .

[0024] Fig . 1 shows a connection assembly according to a first embodiment of the invention . The connecting assembly is designed for connecting two elements 10a, 10b formed as aluminium housing elements 10a , 10b including flanges 12a , 12b configured to be connected to each other, the flanges 12a , 12b including inner sides configured to abut to each other and outer sides facing away from each other . As illustrated in Fig . 2 , inner side of the two flanges 12a , 12b includes a groove accommodating an O-ring 14 . The connection is therefore sealed by the O-ring 14 and the connection assembly must generate a continuous axial pressure to ensure the sealing while simultaneously withststanding a much higher pull-off force in the axial direction .

[0025] The connecting assembly includes a metal band 16 formed as a steel band configured to be strapped around the outer circumference of the flanges 12a, 12b and a tightening device 18 for tightening the metal band 16 . The tightening device 18 is a quick connector including a bolt 18a passing through one trunnion 18b and engaging with an inner tread of another trunnion 18 c, the trunnions 18b, 18c being accommodated in end loops 16a, 16b of the metal band 16 .

[0026] The metal band 16 includes a plurality of longitudinal slots 20 , a total of seven slots 20 in the embodiment illustrated . The longitudinal slots 20 separated by connecting portions 22 in a longitudinal direction . In the connecting portions 22 , the metal band 16 is plain and uninterrupted across its full width . The longitudinal slots 20 are laterally delimited by web portions 20a , 20b of the metal band 16 .

[0027] The web portions 20a , 20b are configured to abut to the outer sides of the flanges 12a , 12b to thereby connect the flanges 12a , 12b when the metal band 16 is being tightened .

[0028] Optionally, the metal band 16 is pre-shaped in an essentially polygonal shape , wherein the longitudinal slots 20 are provided in straight portions of the polygonal shape and the connecting portions 22 are provided in corner portions of the polygonal shape . In this case , the metal band 16 can be pre-shaped such that the radius of curvature at the corner portions is smaller than the radius of curvature of the radially outer surface of the flanges 12a, 12b such that the corner portions protrude over the radially outer surface of the flanges 12a , 12b in an arcshaped manner , wherein the arcs are flattened as a consequence of the tensioning of the band and thereby act as elastic tolerance compensation structures .

[0029] Fig . 3 illustrates one of the slots 20 according to a first embodiment of the invention . In the first embodiment , the slots 20 are substantially rectangular and are provided with radiuses on the corner portions 20c thereof . This makes the band more robust against tear . Figures 4 to 6 show further embodiments of the invention . In order to avoid repetition, the following description of these further embodiments is essentially limited to differences from the first embodiment of the invention . Because of the unchanged features , the s killed person is referred to the description of the first embodiment . The same reference signs are used for features of the further embodiments that have the same or similar effect in order to emphasize the similarities .

[0030] Fig . 4 illustrates a connecting assembly according to a second embodiment of the invention and Fig . 5 is a sectional view of the connecting assembly in the mounted configuration . According to the second embodiment of the invention, at the longitudinal slots 20 are formed as a longitudinal cuts and two transverse cuts at the ends of the longitudinal slot , wherein tab portions 20d, 20e or wings delimited by the longitudinal cut and two transverse cuts are bent outward . A root portion of the outer sides of the flanges 12a , 12b includes a radius or a slope . Since the tab portions 20d, 20e or wings are bent outward, the surface thereof lies flatly on the outer sides of the flanges 12a , 12b , thereby distributing the pressure evenly and avoiding damage of the surface , even for brittle materials and / or cast aluminium.

[0031] Fig . 6 illustrates a connecting assembly according to a third embodiment of the invention in a sectional view . According to the third embodiment of the invention, the tab portions 20f , 20g or wings delimited by the longitudinal cut and two transverse cuts are bent inward . A root portion of the outer sides of the flanges 12a , 12b includes a radius or a slope . Since the tab portions 20f , 20g or wings are bent inward, the inner edge thereof stands perpendicular on the outer sides of the flanges 12a , 12b , thereby being able to transmit high forces onto the flanges 12a , 12b without ris king to slip off . List of reference numbers

[0032] 10a, 10b elements

[0033] 12a, 12b flanges

[0034] 14 0-ring 16 metal band

[0035] 16a, 16b end loops

[0036] 18 tightening device

[0037] 18a bolt

[0038] 18b, 18c trunnions 20 slots

[0039] 20a, 20b web portions

[0040] 22c corner portion

[0041] 20d, 20e tab portion

[0042] 20f, 20g tab portion 22 connecting portions

Claims

Claims1. Connecting assembly for connecting two elements (10a, 10b) including flanges (12a, 12b) configured to be connected to each other, the flanges (12a, 12b) including inner sides configured to abut to each other and outer sides facing away from each other, wherein the connecting assembly includes a metal band (16) configured to be strapped around the outer circumference of the flanges (12a, 12b) and a tightening device (18) for tightening the metal band (16) , characterized in that the metal band (16) includes a plurality of longitudinal slots (20) separated by connecting portions (22) in a longitudinal direction, wherein the longitudinal slots (20) are laterally delimited by web portions (20a, 20b) of the metal band (16) and wherein the web portions (20a, 20b) are configured to abut to the outer sides of the flanges (12a, 12b) to thereby connect the flanges (12a, 12b) when the metal band (16) is being tightened, wherein at least one of the longitudinal slots (20) is formed as a longitudinal cut and two transverse cuts at the ends of the longitudinal slot, wherein tab portions delimited by the longitudinal cut and two transverse cuts are bent inward or outward.

2. Connecting assembly according to claim 1, characterized in that the elements (10a, 10b) are aluminium housing elements (10a, 10b) and the metal band (16) is a steel band.

3. Connecting assembly according to one of the preceding claims , characterized in that the metal band (16) is pre-shaped in an essentially polygonal shape, wherein the longitudinal slots (20) are provided in straight portions of the polygonal shape and the connecting portions (22) are provided in corner portions of the polygonal shape .

4. Connecting assembly according to one of the preceding claims , characterized in that the slots (20) are substantially rectangular and are provided with radiuses on the edge portions thereof.

5. Connecting assembly according to one of the preceding claims , characterized in that a root portion of the outer sides of the flanges (12a, 12b) includes a radius or a slope.

6. Connecting assembly according to one of the preceding claims , characterized in that the inner side of at least one of the flanges (12a, 12b) includes a groove accommodating an O-ring (14) .

7. Connecting assembly according to one of the preceding claims , characterized in that the metal band (16) includes from 4 to 7 slots (20) .

8. Air compressor in including two housing parts and connecting assembly according to one of the preceding claims, wherein the two housing parts are the two elements (10a, 10b) including flanges (12a, 12b) connected by the connecting assembly.

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