阅读说明：本技术 用含水的润滑剂润滑的内燃机 (Internal combustion engine lubricated with aqueous lubricant ) 是由 M·克贝尔 U·古特泽 G·J·麦因加斯纳 于 2019-11-21 设计创作，主要内容包括：本发明涉及一种内燃机(1),所述内燃机具有内燃机内部空间(2),在所述内燃机内部空间中接纳有润滑剂,以便润滑设置在该内燃机内部空间中的至少一个构件(10、11、12),其特征在于,该润滑剂是含水的润滑剂(3)。(The invention relates to an internal combustion engine (1) having an internal combustion engine interior (2) in which a lubricant is received in order to lubricate at least one component (10, 11, 12) arranged in the internal combustion engine interior, characterized in that the lubricant is a water-containing lubricant (3).)

1. An internal combustion engine (1) having an internal combustion engine interior (2) in which a lubricant is received in order to lubricate at least one component (10, 11, 12) arranged in the internal combustion engine interior, characterized in that the lubricant is a water-containing lubricant (3).

2. An internal combustion engine according to claim 1, wherein the engine has water injection means for the planned introduction of water into at least one combustion chamber of the engine.

3. An internal combustion engine according to claim 2, wherein water from the water injection means can be delivered to the aqueous lubricant.

4. Internal combustion engine (1) according to one of the preceding claims, characterized in that the internal combustion engine interior (2) is connected in a fluid-conducting manner with at least one ventilation device (5) for pressure equalization with the environment (9) surrounding the internal combustion engine (1), and that the ventilation device has a semipermeable membrane (8) which is impermeable to water in a first direction, i.e. from a first surface of the membrane to a second surface, and that the first surface of the semipermeable membrane (8) faces the internal combustion engine interior (2), so that the semipermeable membrane (8) closes the internal combustion engine interior (2) against water and water vapor towards the environment (9) surrounding the internal combustion engine (1).

5. An internal combustion engine according to claim 4, characterized in that a further membrane is provided, which is arranged downstream of the semipermeable membrane (8) with reference to the flow direction (6) from the internal combustion engine interior (2) into the environment (9) surrounding the internal combustion engine (1), and which is constructed as a semipermeable membrane and is arranged such that it seals the semipermeable membrane (8) against water and water vapor towards the environment (9) surrounding the internal combustion engine (1).

6. Internal combustion engine according to one of the preceding claims, characterized in that the internal combustion engine (1) is configured as a reciprocating piston internal combustion engine and the at least one component arranged in the internal combustion engine interior (2) is a crankshaft (12).

7. An internal combustion engine according to any one of the preceding claims, wherein the engine comprises a valve train having at least one camshaft, and wherein the camshaft has a friction reducing coating at least in regions.

8. Internal combustion engine according to one of the preceding claims, characterized in that the internal combustion engine has a crankshaft starter generator, and the crankshaft starter generator and the internal combustion engine have a common lubricant reserve and can therefore be supplied with the same aqueous lubricant.

Technical Field

The invention relates to a liquid-lubricated internal combustion engine having a ventilation device. A device in a motor vehicle according to the preamble of claim 1 is generally known from DE102010025980a 1.

Background

The present invention will be described below in connection with an internal combustion engine and an aqueous lubricant for lubricating the internal combustion engine, and the description should not be construed as limiting the invention. Compared to conventional lubricants, aqueous lubricants offer advantages, in particular with regard to efficiency and, in particular, also with regard to temperature behavior. The lubricating properties of such aqueous lubricants are largely dependent on the water content in the lubricant. In the operation of motor vehicles, the devices lubricated with aqueous lubricants, i.e., in particular in the internal combustion engine or in various sections of the internal combustion engine, can reach a temperature at which water is converted into water vapor and escapes from the internal combustion engine, wherein the aqueous lubricants lose their advantages over conventional engine oils as water is lost. In general, it is known to provide a metering device which delivers water to the aqueous lubricant and thus keeps the water content of the aqueous lubricant constant.

Disclosure of Invention

The object of the invention is to provide an internal combustion engine which is supplied with a lubricant containing water. In a preferred embodiment of the invention, the variability of the water content in the aqueous lubricant is improved over conventional internal combustion engines, i.e. the water content in the lubricant remains almost constant during operation of the internal combustion engine. This object is achieved by an internal combustion engine according to claim 1, preferred embodiments of the invention being the subject matter of the dependent claims.

In the sense of the present invention, an internal combustion engine is understood to be a heat engine which is used to drive a motor vehicle, i.e. to provide drive power for overcoming the driving resistance of the motor vehicle, and is preferably designed as a reciprocating piston internal combustion engine, which can preferably be operated according to the diesel or gasoline principle. The internal combustion engine has an internal combustion engine interior in which at least one and preferably a plurality of components are arranged, which are lubricated or cooled at least temporarily by means of a lubricant during operation of the internal combustion engine. Further preferably, a lubricant containing water is completely or at least partially received in the internal combustion engine interior.

Such a component can be understood as a piston, a bearing, a connecting rod or a shaft, in particular a crankshaft. The lubricant is additionally received in the internal combustion engine interior or is preferably introduced into the internal combustion engine interior for lubricating the at least one component.

In addition, the lubricant is designed as an aqueous lubricant, and in the sense of the present invention, an aqueous lubricant is understood to mean a lubricant which has at least 5% by volume or more of water and the remaining constituents of which can be solid, preferably so-called nanoparticles or water-soluble substances. As such aqueous lubricants are known from the prior art, the aqueous lubricants are also referred to in part as water-based lubricants. In particular, the running performance of the internal combustion engine can be improved by using a lubricant containing water.

Furthermore, the internal combustion engine has a ventilation device for pressure compensation, in particular during operation of the internal combustion engine, with the environment surrounding the internal combustion engine, in other words in particular the internal combustion engine interior is connected or connectable in a fluid-conducting manner to this environment by means of the ventilation device. Furthermore, the ventilation device has a semipermeable membrane.

A semi-permeable membrane in the sense of the present invention is understood to be a membrane which is impermeable to water and/or water vapour in a first direction from a first surface to a second surface, and further preferably is permeable to water and/or water vapour in a second direction from the second surface to the first surface. Such membranes or their functional operation are also known in a similar fashion from the use in active breathing sports garments under different trade names.

The semipermeable membrane faces with its first surface the internal combustion engine space, so that an imaginary fluid flow from the internal combustion engine space into the environment surrounding the internal combustion engine should be required to flow through the membrane from its first surface to its second surface. However, this aforementioned flow direction is blocked by the installation position of the semipermeable membrane, and therefore the discharge of water vapor, in particular, from the interior of the internal combustion engine into the environment is prevented or at least strongly limited. Further preferably, the internal combustion engine has a plurality of such ventilation devices. Preferably, the internal combustion engine space is closed in a fluid-tight manner, apart from the at least one ventilation device, from the environment surrounding the internal combustion engine space, so that water vapor is prevented from escaping from the internal combustion engine space. In particular, with the film thus provided, the internal combustion engine space is sealed in a watertight and water-vapor-tight manner with respect to the environment surrounding the internal combustion engine, so that no or only a small amount of moisture can escape from the internal combustion engine space. Thus, with such a semipermeable membrane it is also possible to achieve at least a reduction in the discharge of water or water vapor from the internal combustion engine interior space, and therefore the water content in the aqueous lubricant can be kept constant or almost constant.

In a preferred embodiment of the invention, a further membrane is provided in the ventilation device. Preferably, the further membrane is arranged downstream of the semipermeable membrane with reference to the direction of flow from the interior space of the device into the environment surrounding the combustion engine. Preferably, the further membrane is designed as a semi-permeable membrane and can therefore be understood as a further semi-permeable membrane.

It is further preferred that the further semipermeable membrane is arranged such that it closes the internal combustion engine interior against water and water vapor in an imaginary flow direction from the environment surrounding the internal combustion engine into the internal combustion engine interior. In this case, the further semi-permeable membrane is arranged in the same manner as a mirror image of the semi-permeable membrane (gegengleich). In particular, such an arrangement makes it possible to prevent or at least reduce uncontrolled ingress of water and/or water vapor into the interior of the internal combustion engine.

In a preferred embodiment, the internal combustion engine is designed as a reciprocating piston internal combustion engine, which is preferably operable on a two-stroke principle or preferably on a four-stroke principle, and which is additionally accommodated in a drive train of the motor vehicle, which drive train is designed to provide a driving force for overcoming driving resistance (air resistance, friction resistance, climbing resistance, etc.). In particular, the at least one component arranged in the internal combustion engine interior is designed as a crankshaft, which is connected to at least one piston by means of at least one connecting rod, and further preferably the internal combustion engine interior is at least partially delimited by a so-called engine oil pan, wherein preferably a lubricant containing water can be received at least temporarily and at least partially in the engine oil pan.

In a preferred embodiment, the internal combustion engine has a cooling circuit, which is provided in particular to absorb heat from the internal combustion engine and to discharge it to the environment surrounding the internal combustion engine. Preferably, the cooling circuit for cooling the internal combustion engine is traversed by the aqueous lubricant, and further preferably at least one heat exchanger is provided in the cooling circuit, which can be traversed by the aqueous lubricant, and further preferably the internal combustion engine has no further cooling circuit apart from the cooling circuit, but instead the cooling circuit, which can be traversed by the aqueous lubricant, is a conventional cooling circuit known from the prior art, in particular a so-called cooling water circuit of a conventional internal combustion engine, through which the cooling water circuit can be traversed by means of a medium, in particular cooling water, which is additional to the aqueous lubricant. In particular, by using a water-containing lubricant in the cooling circuit, a simplification of the internal combustion engine can be achieved, in particular, by such a simplification of the cooling circuit, the water-containing lubricant is used directly for cooling the internal combustion engine.

In a preferred embodiment of the invention, the aqueous lubricant is additionally used for lubricating a so-called valve train of an internal combustion engine. In this context, a valve train is understood to mean a device of an internal combustion engine, with which the gas exchange of the internal combustion engine can be controlled, in particular, the valve train having at least one camshaft. In particular, by using a unified lubricant for an internal combustion engine, an internal combustion engine having a simple configuration and high efficiency can be realized.

In a preferred embodiment, the internal combustion engine has a so-called crankshaft starter generator. A crankshaft starter generator is understood to mean an electromechanical energy converter, in particular an electric motor generator, which can be coupled to a crankshaft of an internal combustion engine or preferably is coupled to a crankshaft of an internal combustion engine and which is at least designed for starting the internal combustion engine from a standstill. Preferably, the crankshaft starter generator is arranged concentrically to the crankshaft of the internal combustion engine or is preferably connectable to the transmission, and further preferably, the crankshaft starter generator is arranged axially parallel to the crankshaft. The crankshaft starter generator can be supplied with a liquid medium, in particular with which it can be lubricated and/or cooled. Preferably, the aqueous lubricant is used to supply the crankshaft starter generator, and further preferably, the crankshaft starter generator and the internal combustion engine therefore have a common lubricant reserve. In this context, a common lubricant reserve is understood to mean that at least the internal combustion engine and the crankshaft starter generator are supplied or are supplied by the same aqueous lubricant, i.e., in particular by a single or common aqueous lubricant. In particular, such a design makes it possible to achieve a particularly simple design of an internal combustion engine having a starter generator, since the internal combustion engine comprises only a lubricant reserve with a common lubricant.

Further preferably, at least one component, in particular a component of an internal combustion engine and/or a crankshaft-starter-generator, which may be supplied with the aqueous lubricant, has at least in regions a friction-reducing coating, preferably a "Diamond Like Carbon" coating (DLC coating) or the Like. Preferably, at least two directly contacting components, preferably the piston and the piston running surface, have such a coating for reducing friction. In particular, a so-called "super-lubrication" can be achieved by such a coating of at least one of the components. Super-lubrication is understood here to mean the so-called super-lubrication capacity, in which case the friction can disappear almost completely. Preferably, at least one component of the valve train has such a coating, and particularly preferably at least one camshaft has such a coating at least in sections or preferably completely. In particular, by using such a coating, a particularly low-friction operation of the internal combustion engine can be achieved.

In a preferred embodiment, the internal combustion engine has a water injection device. In particular, a water injection device is understood to mean a device with which water can be specifically delivered to at least one combustion chamber of an internal combustion engine. Such water jet devices are known from the prior art. Further preferably, the water injection device has a metering device, with which water can be delivered to the aqueous lubricant. It is further preferred that the metering device is provided for maintaining the proportion of water in the aqueous lubricant within a predeterminable range and thus for facilitating efficient operation of the internal combustion engine. In particular, by means of the water introduced by the water injection device into the at least one combustion chamber of the internal combustion engine, the emissions of the internal combustion engine can be positively influenced and, in addition, a positive interaction between the water injection device of the internal combustion engine and the water-containing lubricant takes place.

Drawings

The various features of the invention are explained in more detail below with the aid of the drawings.

Fig. 1 shows an internal combustion engine with a water-containing lubricant and a ventilator.

Detailed Description

Fig. 1 shows a schematic cross section of an internal combustion engine 1. In the internal combustion engine 1, as members to be lubricated, a crankshaft 12, as well as a connecting rod 10 and a piston 11, and corresponding bearings and bearing sites are provided. For lubricating these components, an aqueous lubricant 3 is received in the internal combustion engine interior 2. For ventilation, the internal combustion engine 1 comprises a ventilator 5 (ventilation device) with a semipermeable membrane 8. For controlling the gas exchange, the internal combustion engine 1 has a cylinder head 4. In the cylinder head 4, a camshaft is provided which can be driven by a valve train (not shown) and with which the gas exchange in the internal combustion engine 1 can be controlled by means of so-called inlet valves and outlet valves.

The semipermeable membrane 8 is arranged such that it is impermeable to water or water vapor in the flow direction 6 from the combustion engine interior 2 into the environment 9 surrounding the combustion engine 1. In addition, the semipermeable membrane 8 is permeable to water or water vapor with reference to the flow direction 7 from the environment 9 surrounding the internal combustion engine 1 into the internal combustion engine interior 2.

With such a design of the internal combustion engine 1, it is possible to achieve that no or only a small amount of moisture (water/water vapor) escapes from the internal combustion engine 1 and that the water content in the water-containing lubricant 3 in the internal combustion engine interior 2 is therefore at least substantially constant, in particular at least substantially constant during operation of the internal combustion engine.

In other words, the invention proposes the use of aqueous lubricants for lubrication and/or cooling in internal combustion engines. By this use:

a reduction in viscosity and thus a reduction in power loss/drag losses can be achieved in comparison with conventional lubricating oils, i.e. lubricants which contain no water in particular;

by improving the thermal properties (thermal transition, heat capacity) of aqueous lubricants, a reduction in the volume of the lubricating oil can be achieved relative to conventional lubricating oils;

a synergistic effect (cooling capacity, potential for the application of only one medium) with the cooling water circuit can be achieved, and a so-called depreciation/replacement of the cooling water circuit can thereby be achieved;

also, friction reduction can be achieved by using coated friction pairs/components (mainly DLC on the piston and cylinder block), and potential for creating super-lubrication is obtained especially when using coated friction pairs.

List of reference numerals

1 internal combustion engine

2 internal combustion engine inner space

3 aqueous lubricant

4 cylinder head

5 ventilator

6 flow direction from the internal combustion engine

7 flow direction into an internal combustion engine

8 semi-permeable membrane

9 environment

10 connecting rod with bearing

11 piston

12 crankshaft with bearing

13 combustion chamber