WO2010130238A2

WO2010130238A2 - Vacuum pump

Info

Publication number: WO2010130238A2
Application number: PCT/DE2010/000472
Authority: WO
Inventors: Carsten Sczesny; Robert Deipenwisch; Hans Jürgen LAUTH
Original assignee: Ixetic Hückeswagen Gmbh
Priority date: 2009-05-15
Filing date: 2010-04-26
Publication date: 2010-11-18
Also published as: WO2010130238A3; DE112010002012A5

Abstract

Disclosed is a vacuum pump comprising a suction chamber in which a negative pressure is produced when the vacuum pump is operated, and a lubricant feed. The disclosed vacuum pump is characterized in that the lubricant feed communicates with the suction chamber in such a manner that the vacuum pump is self-priming for the lubricant owing to the negative pressure produced during operation of the vacuum pump.

Description

vacuum pump

The invention relates to a vacuum pump with a suction chamber, in which a vacuum is generated during operation of the vacuum pump, and with a lubricant inlet.

The vacuum pump may be designed as a vane pump, as disclosed, for example, in International Publication WO 2004/074687 A2. Vacuum pumps are used in motor vehicles, for example, to generate a vacuum in a designed as Saugluftverstärker brake booster. As the lubricant for the vacuum pump, engine oil supplied from a lubrication system of the vehicle may be used. As a lubricant for the vacuum pump and water can be used. Lubricant-driven vacuum pumps are also referred to as wet running. Similarly, vacuum pumps that are operated without lubricant, referred to as dry running. Wet-running vacuum pumps are driven, for example, by a cam or distributor shaft or by a crankshaft of an internal combustion engine. Dry running vacuum pumps are driven, for example, by an electric motor.

The object of the invention is to improve the supply of a vacuum pump, which has a suction chamber, in which a vacuum is generated during operation of the vacuum pump, and a lubricant inlet, with lubricant. In this case, the supply of the vacuum pump with lubricant in a motor vehicle, in particular a hybrid vehicle, to be ensured even if an internal combustion engine of the motor vehicle is turned off.

The object is in a vacuum pump with a suction chamber, in which a vacuum is generated during operation of the vacuum pump, and with a lubricant inlet, achieved in that the lubricant inlet is in communication with the suction chamber that the vacuum pump generated by the operation of the vacuum pump Negative pressure itself is absorbent for the lubricant. The lubricant supply of the vacuum pump is independent of the lubricant supply, in particular a pressure circulation lubrication, an internal combustion engine and thus of its operating state according to an essential aspect of the invention. A preferred embodiment of the vacuum pump is characterized in that the lubricant inlet is in communication with a region of a working space in which a large negative pressure is generated during operation of the vacuum pump. This ensures that the vacuum pump is supplied with sufficient lubricant in all operating conditions.

A further preferred embodiment of the vacuum pump is characterized in that the lubricant inlet is in communication with a region of the working space in which, in operation of the vacuum pump, based on a control time, early negative pressure is generated. This ensures that the lubricant supply begins almost simultaneously with a suction of the vacuum pump.

A further preferred embodiment of the vacuum pump is characterized in that the lubricant inlet is in communication with a lubricant reservoir from which is sucked by the vacuum generated during operation of the vacuum pump lubricant in the vacuum pump in the vacuum pump for lubricating bearings, for cooling and / or for sealing gaps. The lubricant reservoir is preferably an oil sump or an oil sump of an internal combustion engine of a motor vehicle.

A further preferred embodiment of the vacuum pump is characterized in that extends from the lubricant inlet at least one Schmiermittelzuführkanal for supplying lubricant through a pump housing in the suction chamber. The lubricant supply channel can be guided past at least one bearing point in the interior of the pump housing and / or at least one gap in the interior of the pump housing.

Another preferred embodiment of the vacuum pump is characterized in that the vacuum pump is electrically driven. According to an essential aspect of the invention, the vacuum pump is not driven by the internal combustion engine, but preferably electrically. This ensures that the vacuum pump can be driven even when the internal combustion engine is switched off. As a result, in particular a start-stop operation, preferably a hybrid vehicle with an internal combustion engine and an electric machine, is made possible. A further preferred embodiment of the vacuum pump is characterized in that the vacuum pump is designed as a positive displacement pump with at least one displacement body. The vacuum pump preferably comprises a rotor, via which the displacement body is set in motion. The vacuum pump may be designed, for example, as a gear pump or reciprocating pump.

A further preferred embodiment of the vacuum pump is characterized in that the vacuum pump is designed as a vane pump with at least one vane and a rotor. The rotor preferably comprises a bearing portion, with which the rotor is rotatably mounted in a pump housing. Among other things, the lubricant serves to lubricate the bearing section of the rotor. The lubricant can be sucked into the suction chamber of the vacuum pump via the bearing point of the rotor, where it seals during operation occurring gap between the wing and the pump housing, in particular a circulation contour.

A further preferred exemplary embodiment of the vacuum pump is characterized in that the vacuum pump has an outlet which is connected to a lubricant reservoir or reservoir from which lubricant is sucked into the vacuum pump by the negative pressure generated during operation of the vacuum pump. About the output of the lubricant reservoir, an air-oil mixture is supplied, which was pressurized in a pressure chamber of the vacuum pump.

Another preferred embodiment of the vacuum pump is characterized in that the outlet of the vacuum pump is connected to the lubricant reservoir via an outlet channel. The outlet channel can run, for example, through a hose or a housing part of the vacuum pump or an internal combustion engine.

A further preferred embodiment of the vacuum pump is characterized in that the outlet channel opens above a lubricant level of the lubricant reservoir. This ensures that the lubricant in the lubricant reservoir is not foamed by the discharged from the vacuum pump air-oil mixture.

A further preferred embodiment of the vacuum pump is characterized in that the lubricant inlet of the vacuum pump via an input channel with the Lubricant reservoir is in communication. The inlet channel may pass through a hose or through a housing part of the vacuum pump or an internal combustion engine.

A further preferred embodiment of the vacuum pump is characterized in that the inlet channel opens below a lubricant level in the lubricant reservoir. This ensures that only lubricant and no air is sucked through the lubricant inlet of the vacuum pump.

A further preferred embodiment of the vacuum pump is characterized in that the inlet channel and the outlet channel pass through a two-chamber tube for the lubricant, which is connected to the vacuum pump. As a result, the installation space and the installation effort for connecting the vacuum pump to the lubricant reservoir can be reduced.

Another preferred embodiment of the vacuum pump is characterized in that the lubricant input upstream or downstream of a throttle. The throttle is designed and arranged so that a sufficient, but not too large amount of lubricant is sucked through the lubricant inlet in the vacuum pump, without the vacuum generation is impaired.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, an embodiment is described in detail. Show it:

Figure 1 shows a part of a vacuum pump according to an embodiment of the

Invention in longitudinal section;

Figure 2 is a greatly simplified representation of an internal combustion engine with a

Lubricant reservoir to which the vacuum pump of Figure 1 is connected and

Figure 3 is a schematic representation of the vacuum pump in cross section.

FIG. 1 shows a longitudinal section of a vacuum pump 1 with a pump housing 2. The pump housing 2 comprises a pump housing pot 3, which is protected by a lid 4. is closed. In the pump housing 2, a rotor 5 is rotatably received. The rotor 5 comprises a rotor bearing section 6, with which the rotor 5 is rotatably mounted in the housing pot 3. In addition, the rotor 5 comprises a wing receiving slot 7 through which at least one wing 8 is guided within a circulation contour 10 in the pump housing 2. At the free end of the rotor bearing section 6, the rotor 5 is driven by an electric motor.

The pump housing 2 bounded in its interior a working space 14 which is divided by the moving wing in a suction chamber 15 and a pressure chamber. The suction chamber 15 communicates with an inlet port of the vacuum pump 1 in connection, via which a working medium, in particular air, is sucked into the suction chamber 15. The sucked or sucked air is compressed by the moving wing 8 in the pressure space and discharged through an outlet of the vacuum pump 1.

The suction chamber 15 of the vacuum pump 1 is in accordance with an essential aspect of the invention via a Schmiermittelzuführkanal 18, which is shown exaggerated in size, with a lubricant inlet 16 of the vacuum pump 1 in connection. Via the lubricant inlet 16 and the lubricant supply channel 18, lubricant is sucked in, which serves in the vacuum pump 1 for cooling, lubricating bearings and / or sealing of gaps. According to one essential aspect of the invention, the vacuum pump 1 driven by the electric motor is made wet-running.

FIG. 2 shows in a greatly simplified manner how the vacuum pump 1 from FIG. 1 can be connected to a lubrication system of a motor vehicle. The vacuum pump 1 is electrically driven by an electric motor 20 and serves to generate via a vacuum line 22, a vacuum or a negative pressure in a brake booster 24, which is designed as Saugluftverstärker. By an arrow 25 is indicated, as the vacuum pump 1 sucks air from the brake booster 24.

An internal combustion engine 30 with a lubrication system is indicated by a rectangle. The lubrication system serves to supply all lubricating oil to be lubricated and cooled points in the internal combustion engine. The lubrication system includes a lubricant reservoir 32 that includes a liquid lubricant, such as oil. By a line 34 and a corresponding symbol, the surface or the liquid level of the lubricant is indicated. The lubrication system allows pressure circulation lubrication of the Internal combustion engine. For this purpose, a driven by the internal combustion engine (not shown) lubricant pump is provided, which is designed as a pressure pump and serves to supply the lubrication points with the engine running with lubricant.

Conventional electrically driven vacuum pumps or vacuum pumps, in particular in vane construction, for motor vehicles are running dry running. According to one essential aspect of the invention, the vacuum pump 1 driven by the electric motor 20 is made wet-running. For this purpose, a lubricant supply channel 18 is connected to the lubricant inlet 16 of the vacuum pump 1, which connects the lubricant inlet 16 with the lubricant reservoir 32. The inlet channel 41 opens below the lubricant surface or the lubricant level 34 into the lubricant reservoir 32 in order, as indicated by an arrow 42, to suck lubricant from the lubricant reservoir 32 into the vacuum pump 1.

The lubricant fulfills the following functions in the vacuum pump 1: Lubrication of the friction points, whereby the wear and the friction loss can be reduced; Cooling the vacuum pump 1, whereby a particularly compact design is made possible; Caulking the column, whereby shorter suction times during operation of the vacuum pump 1 are made possible. Due to the lubrication of the electrically driven vacuum pump 1, the energy requirement can be reduced due to reduced friction and reduced duty cycle of the vacuum pump 1. Due to the better sealing of the gaps in the interior of the vacuum pump 1, moreover, its volumetric efficiency can be improved. Finally, by reducing the wear and reducing the duty cycle, the life of the vacuum pump can be increased.

Another significant advantage of the vacuum pump 1 according to the invention is that it allows a start-stop operation of the internal combustion engine. By the electric drive, a sufficient supply of the vacuum pump 1 is ensured with lubricant even at a standstill of the internal combustion engine. Since the vacuum pump 1 is designed to be self-priming, lubricant is sucked in independently even when the internal combustion engine is switched off via the electric drive.

In the vacuum pump 1, the lubricant mixes with the sucked by the brake booster 24 air to an oil-air mixture, which via an output channel 45 again the lubricant reservoir 32 is supplied, as indicated by an arrow 46. The exit passage 45 opens above the lubricant level 34 to prevent the lubricant in the lubricant reservoir 32 from being foamed by the air contained in the oil-air mixture. According to a further aspect of the invention, the inlet channel 41 and the outlet channel 45 are provided in a two-chamber tube 50, which is indicated by two lines 51, 52.

In the input channel 41, a throttle 55 is indicated between the lubricant reservoir 32 and the lubricant inlet 16 of the vacuum pump 1. The throttle 55 prevents the vacuum pump 1 from sucking in too much lubricant from the lubricant reservoir 32.

In Figure 3, the vacuum pump 1 is shown schematically in cross section. The vacuum pump 1 comprises a housing 102 in which a rotor 104 is rotatably arranged. In or on the rotor 104, a wing 105 is slidably guided. The rotor 104 hugs with its outer contour in a so-called Schmiegespalt to an inner contour of the housing 102. The center of the Schmiegespalts represents a bottom dead center 106 of the vacuum pump 1.

By the wing 105, a working space of the vacuum pump 1 is divided in the housing 102 into a suction chamber 108 and a pressure chamber 109. The suction chamber 108 communicates with a suction port, via which a medium, in particular air or an air-oil mixture, is sucked into the suction chamber 108 and conveyed out of the pressure chamber 109. The aspirated medium passes through an inlet port 114 into the suction chamber 108. In a preferred application, the mono-cell vane pump is used to apply a negative pressure, that is a vacuum, to a brake booster of a motor vehicle.

The pressurized medium in the pressure chamber 109 passes through an outlet opening 110, which is designed as a slot 112, in the vicinity of the vacuum pump 1, where atmospheric pressure prevails. During normal operation of the vacuum pump 1, air is normally expelled from the pressure chamber 109 through the outlet port 110 with oil contents contained therein. In order to reduce the power consumption of the vacuum pump 1, the outlet opening 110 is part of a check valve 113, which prevents backflow of air from the environment into the pressure chamber 109, as long as the pressure in the pressure chamber 109 is less than the ambient pressure. According to one essential aspect of the invention, the lubricant inlet designated by 16 in FIGS. 1 and 2 is arranged in the vicinity of the inlet opening 114, which is also referred to as a suction connection, and / or in the vicinity of the nipping gap, ie in an area of the working space 14 and suction chamber 108, in which in operation of the vacuum pump 1, based on a control time, is generated early under pressure. This ensures that the lubricant supply begins almost simultaneously with a suction of the vacuum pump 1.

Bezugszelchenliste

Vacuum pump 102 housing

Pump housing 104 rotor

Pump housing pot 105 wings

Cover 106 dead center

Rotor 108 suction chamber

Rotor bearing section 109 pressure chamber

Wing receiving slot 110 outlet opening

Wing 112 slot

Circumferential contour 114 inlet opening

working space

suction

lubricant input

lubricant supply

electric motor

Vacuum line

Brake booster

arrow

Internal combustion engine

lubricant reservoir

lubricant levels

input channel

arrow

output channel

arrow

Two-chamber hose

line

throttle

Claims

claims

1. Vacuum pump with a suction chamber (15), in which during operation of the vacuum pump (1), a negative pressure is generated, and with a lubricant inlet (16), characterized in that the lubricant inlet (16) so with the suction chamber (15) in connection stands that the vacuum pump (1) by the negative pressure generated during operation of the vacuum pump (1) is itself sucking for the lubricant.

2. Vacuum pump according to claim 1, characterized in that the lubricant inlet (16) with a portion of a working space (14) is in communication, in which a large negative pressure is generated during operation of the vacuum pump.

3. Vacuum pump according to claim 2, characterized in that the lubricant inlet (16) with a portion of the working space (14) is in communication, in which during operation of the vacuum pump (1), based on a control time, early negative pressure is generated.

4. Vacuum pump according to one of the preceding claims, characterized in that the lubricant inlet (16) with a lubricant reservoir (32) is in communication, from which by the operation of the vacuum pump (1) generated negative pressure lubricant in the vacuum pump (1) is sucked used in the vacuum pump (1) for lubricating bearings, for cooling and / or for sealing gaps.

5. Vacuum pump according to one of the preceding claims, characterized in that extending from the lubricant inlet (16) at least one Schmiermittelzuführkanal (18) for supplying lubricant through a pump housing (2) in the suction chamber (15).

6. Vacuum pump according to one of the preceding claims, characterized in that the vacuum pump (1) is electrically driven.

7. Vacuum pump according to one of the preceding claims, characterized in that the vacuum pump (1) is designed as a positive displacement pump with at least one displacement body.

8. Vacuum pump according to one of the preceding claims, characterized in that the vacuum pump (1) is designed as a vane pump with at least one wing (8) and a rotor (5).

9. Vacuum pump according to one of the preceding claims, characterized in that the vacuum pump has an output which communicates with one or the lubricant reservoir (32), from the by the operation of the vacuum pump (1) generated negative pressure lubricant into the vacuum pump ( 1) is sucked.

10. Vacuum pump according to claim 9, characterized in that the output of the vacuum pump (1) via an output channel (45) with the lubricant reservoir (32) is in communication.

11. Vacuum pump according to claim 10, characterized in that the output channel (45) above a lubricant level (34) of the lubricant reservoir (32) opens.

12. Vacuum pump according to claim 10 or 11, characterized in that the lubricant inlet (16) of the vacuum pump (1) via an input channel (41) with the lubricant reservoir (32) is in communication.

13. Vacuum pump according to claim 12, characterized in that the inlet channel (41) opens below a lubricant level (34) in the lubricant reservoir (32).

14. Vacuum pump according to claim 12 or 13, characterized in that the inlet channel (41) and the outlet channel (45) extend through a two-chamber tube (50) for the lubricant, which is connected to the vacuum pump (1).

15. Vacuum pump according to one of the preceding claims, characterized in that the lubricant inlet (16) is a throttle (55) upstream or downstream.