COMPONENT WITH MOULDED-ON SEAL

Abstract

A method for manufacturing a component with moulded-on seal, in particular a pump component. The component is laid in an injection-moulding tool, then a sealing material is injected from an injection gate into the injection-moulding tool and fills a cavity on one side of the component. Sufficient sealing material is injected for a part of the sealing material to pass from the cavity, via an overflow channel connected to the cavity, into an overflow chamber which is provided inside the contour of the component. A component can includes the moulded-on seal.

Claims

1. Method for manufacturing a component with moulded-on seal, in particular a pump component, wherein the component is laid in an injection-moulding tool, then a sealing material is injected from an injection gate into the injection-moulding tool and fills a cavity on one side of the component, wherein sufficient sealing material is injected for a part of the sealing material to pass from the cavity, via an overflow channel connected to the cavity, into an overflow chamber which is provided inside the contour of the component.

2. Method according to claim 1, wherein starting from the injection gate, the sealing material fills a cavity on an end face of the component and, through overspill channels arranged in the component, fills the cavity connected to the overflow channel, wherein the cavity connected to the overflow channel is arranged on an end face of the component facing away from the injection gate.

3. Method according to claim 1, wherein the overflow channel is provided in the component.

4. Method according to claim 1, wherein the overflow channel is provided in the injection-moulding tool.

5. Method according to claim 1, wherein sealing material flowing into the overflow chamber encloses and compresses a gas present in the overflow chamber.

6. Component with moulded-on seal, in particular a pump component, having an overflow chamber which is formed inside a contour of the component and is provided for receiving a part of the injected sealing material during the injection moulding of the seal.

7. Component according to claim 6, wherein the seal has two seal portions which are arranged on two mutually opposite end faces of the component, wherein the two seal portions are integrally connected together by means of at least one overspill channel, and wherein one of the seal portions has an injection gate and the overflow chamber is assigned to the other seal portion.

8. Component according to claim 6, wherein the overflow chamber is connected via an overflow channel to the region in which the seal is arranged.

9. Component according to claim 8, wherein the overflow chamber, with the exception of the connection to the overflow channel, is gas-tight.

10. Component according to claim 7, wherein the overflow chamber is arranged between the two end faces of the component.

11. Component according to claim 6, wherein overflow chamber has a curved cross-section.

12. Component according to claim 7, wherein the overflow chamber is very much longer in an extent direction from the one end face to the other end face of the component than in the cross-sectional direction.

13. Component according to claim 7, wherein the two seal portions are annular and the overflow chamber is arranged radially outside the seal portions.

14. Component according to claim 6, having a protrusion which protrudes into the overflow chamber and is arranged transversely to a flow direction of sealing material flowing into the overflow chamber.

15. Method according to claim 2, wherein the overflow channel is provided in the component.

16. Method according to claim 2, wherein the overflow channel is provided in the injection-moulding tool.

17. Method according to claim 2, wherein sealing material flowing into the overflow chamber encloses and compresses a gas present in the overflow chamber.

18. Component according to claim 7, wherein the overflow chamber is connected via an overflow channel to the region in which the seal is arranged.

19. Component according to claim 8, wherein the overflow chamber is arranged between the two end faces of the component.

20. Component according to claim 7, wherein overflow chamber has a curved cross-section.

Description

[0023] Further features and advantages of the invention will emerge from the following description and from the appended drawings, to which reference is made. In the drawings:

[0024] FIG. 1 shows a perspective view of a one-piece seal with two seal portions for a pump component;

[0025] FIG. 2 shows a perspective view of a pump component with an integral moulded-on seal;

[0026] FIG. 3 shows a first sectional view of the pump component from FIG. 2;

[0027] FIG. 4 shows a second sectional view of the pump component from FIG. 2;

[0028] FIG. 5 shows an end face view of the pump component from FIG. 2;

[0029] FIG. 6 shows an extract of the pump component from FIG. 2 which has a filled overflow chamber and an overflow channel;

[0030] FIG. 7 shows an extract of a pump component which has a filled overflow chamber with a protrusion; and

[0031] FIG. 8 shows a perspective view of an injection-moulding tool for manufacture of a component with an integral moulded-on seal.

[0032] FIG. 1 shows a one-piece seal 12 for components 10, in particular pump components, for example a pump housing. The pump is in particular a hydraulic pump for supplying a transmission of an electric or hybrid drive module of a motor vehicle.

[0033] The seal 12 is produced by moulding onto or over a pump component 10 and has two annular seal portions 20, 22. The seal portions 20, 22 are arranged spaced apart from one another on an axis and are connected together by several overspill webs 18.

[0034] Evidently, the example shown in FIG. 1 should be regarded purely as an example. Embodiments with simpler geometry are also possible, in particular those in which the seal 12 has a single seal portion 20 arranged on one side of the component 10.

[0035] In the exemplary embodiment shown in FIG. 1, the two seals portions 20, 22 are provided for sealing the pump component 10 against a housing cover and/or other attachments on two opposing end faces 14, 16.

[0036] The integral design of the seal 12 means that the component 10 can be mounted more easily than conventional two-piece systems, which ensures a particularly high component reliability.

[0037] FIGS. 2 to 6 show various views of a pump component 10 with such an integral moulded-on seal 12.

[0038] In the exemplary embodiment, the pump component 10 is an injection moulding produced from a thermoplastic material. The seal 12 is also an injection moulding and may for example be made of rubber, particular fluorocarbon rubber.

[0039] The seal 12 and the pump component 10 are designed such that the two seal portions 20, 22 are arranged on two mutually opposite end faces 14, 16 of the pump component 10.

[0040] In this exemplary embodiment, the two seal portions 20, 22 are connected via six overspill channels 18 which run through the pump component 10. The overspill channels 18 are evenly spaced apart from one another over an edge region of the pump component 10.

[0041] One of the seal portions 20 has an injection gate 26.

[0042] The opposite seal portion 22 is connected to an overflow chamber 34 via an overflow channel 32. The overflow channel is arranged inside a contour of the component 10 and is provided to receive surplus sealing material during injection moulding of the seal 12, and thereby compensate for fluctuations of process parameters, for example the cavity pressure.

[0043] Evidently, in addition to the example described, embodiments with several overflow chambers 34 are also conceivable.

[0044] FIGS. 4 to 6 show various views of an exemplary arrangement of the overflow chamber 34 in the component 10. The overflow chamber 34 extends between the two end faces 14, 16 of the component. In this extent direction, the overflow chamber 34 is very much longer than in its cross-sectional direction perpendicular thereto. This very compact arrangement avoids competition for installation space with the overspill channels 18.

[0045] The geometry of the overflow chamber 34 is not restricted to the embodiment variants shown in FIGS. 4 to 6. In particular, spirally curved overflow chambers 34 or ones tapering in cross-section are conceivable, for example in order to provide a smaller or larger overflow volume 1 and/or a volume precisely adapted to the process parameters.

[0046] FIG. 7 shows as an example a second embodiment variant of an overflow chamber 34 with a protrusion 36 which is arranged transversely to a flow direction of sealing material flowing into the overflow chamber 34. In this variant, the protrusion 36 reduces the overflow volume and fixes the sealing material.

[0047] As evident from FIGS. 4 to 6, the overflow chamber 34 is arranged radially outside the seal portions 20, 22. The volume lying inside the seal 12 accordingly remains untouched and may be used as a working and/or pump volume.

[0048] In the exemplary embodiment, the overflow chamber 34 has only one opening which is connected to the overflow channel 32. The walls of the overflow chamber 34 are gas-tight. It is therefore possible to enclose a gas in the overflow chamber 34 during injection-moulding of the seal 12, and build up a counter-pressure on the sealing material flowing into the overflow chamber 12. The counter-pressure may, as described above, have a positive effect on the quality of the seal 12.

[0049] For illustration, FIG. 6 shows a view of a filled overflow chamber 34, looking onto the opening, and the overflow channel 32.

[0050] The pump component 10 with moulded-on seal 12 shown in FIGS. 2 to 6 is produced with an exemplary embodiment of a method according to the invention. An injection-moulding tool 24, as shown in FIG. 8, is used here. The method is described in more detail below.

[0051] At the start of the method, the pump component 10 is laid in the injection-moulding tool 24. The component 10 is positioned such that between its end faces 14, 16 and the injection-moulding tool 24, cavities 28, 30 are formed in which the two seal portions 20, 22 are moulded.

[0052] Evidently, the method according to the invention is not limited to the exemplary embodiment described. In particular, embodiments are also possible in which a component 10 is positioned in an injection-moulding tool 24 such that only a single cavity is formed on one side of the component 10.

[0053] In the embodiment variant described, the sealing material is injected into the injection-moulding tool 24 from an injection gate 26.

[0054] The sealing material passes from the injection gate 26 into the cavity 28 and fills this. Through the overspill channels 18 in the pump component 10, the sealing material also enters the other cavity 30 on the opposite end face 16 of the component 10 and fills this.

[0055] Enough sealing material is injected for part of the sealing material to flow from the latter cavity 30 via the overflow channel 32 into the overflow chamber 34.

[0056] In this exemplary embodiment, the overflow channel 32—as shown in FIG. 6—is formed by a depression in the end face 16 of the pump component 10.

[0057] Alternatively or additionally, it is also conceivable that the injection-moulding tool 24 is fitted with additional cavities forming overflow channels.

[0058] When flowing into the overflow chamber 34, the sealing material encloses gas present in the overflow chamber 34 and compresses this, whereby a counter-pressure is produced which may have a positive effect on the quality of the seal 12.

[0059] When the cavities 28, 30 are completely filled with sealing material, said material is cooled. It then sets and forms the seal 12.

[0060] In a final step, the injection-moulding tool 24 is opened and the component 10 with moulded-on seal 12 is ejected.