US-20260126112-A1 - METHOD FOR OPERATING A SUPPLY SYSTEM AND SUPPLY SYSTEM

US20260126112A1US 20260126112 A1US20260126112 A1US 20260126112A1US-20260126112-A1

Abstract

A method is provided for operating a supply system in which drive system components are supplied with lubricant and/or coolant. During normal operation of the drive system, an electrically powered feed pump is operated to deliver lubricant and/or coolant in the supply system to the drive system components. During a special operating mode, the electrically powered feed pump is switched off while the drive system is still operating so that at least some of the drive system components are supplied with lubricant and/or coolant only by a mechanically driven feed pump that is driven by a drive output of a motor vehicle drivetrain comprising the drive system. In this case, during operation, the mechanically driven feed pump only delivers a minimum quantity of lubricant and/or coolant that corresponds to a minimum demand required for supplying some of the components.

Inventors

Sebastian Heine
Markus Eisele
Roland Mair
Andreas Acker

Assignees

ZF FRIEDRICHSHAFEN AG

Dates

Publication Date: 20260507
Application Date: 20251103
Priority Date: 20241104

Claims (10)

1 . A method for operating a supply system ( 10 ; 20 ), in which components ( 11 , 12 , 13 , 14 ) of a drive system ( 9 ) are supplied with lubricant and/or coolant, the method comprising: operating an electrically powered feed pump ( 15 ) during normal operation of the drive system ( 9 ) thereby delivering lubricant and/or coolant in the supply system ( 10 ; 20 ) to the components ( 11 , 12 , 13 , 14 ); switching off the electrically powered feed pump ( 15 ) while the drive system ( 9 ) is still operating; supplying at least some components ( 11 , 14 ) of the components ( 11 , 12 , 13 , 14 ) in the supply system ( 10 ; 20 ) with lubricant and/or coolant only by a mechanically driven feed pump ( 16 ); driving the mechanically driven feed pump ( 16 ) by a drive output ( 18 ) of a motor vehicle drivetrain ( 2 ) comprising the drive system ( 9 ); and delivering, when the mechanically driven feed pump ( 16 ) is operating, only a minimum quantity of lubricant and/or coolant that corresponds to a minimum demand required for supplying the at least some components ( 11 , 14 ) of the components ( 11 , 12 , 13 , 14 ).
2 . The method according to claim 1 , wherein the normal operating mode includes operating the mechanically driven feed pump ( 16 ) in addition to the electrically powered feed pump ( 15 ).
3 . The method according to claim 1 , comprising: decoupling, during the normal operating mode, the mechanically driven feed pump (16) from the drive output ( 18 ), thereby turning off the mechanically driven feed pump ( 16 ).
4 . The method according to claim 3 , wherein decoupling the mechanically driven feed pump ( 16 ) is performed as a function of a pressure in the supply system ( 10 ; 20 ).
5 . The method according to claim 1 , wherein during the special operating mode only the at least some components ( 11 , 14 ) of the components ( 11 , 12 , 13 , 14 ) are supplied to which it is essential to supply lubricant and/or coolant permanently while the drive system ( 9 ) is operating.
6 . The method according to claim 1 , comprising: delivering, by the electrically powered feed pump during normal operation, only as much lubricant and/or coolant as is required.
7 . A supply system ( 10 ; 20 ), in which configured to supply components ( 11 , 12 , 13 , 14 ) of a drive system ( 9 ) with lubricant and/or coolant, the supply system comprising: an electrically powered feed pump ( 15 ); a mechanically driven feed pump ( 16 ) having a drive input; and a drive output of a motor vehicle drivetrain that includes the supply system, the drive output coupled to the drive input to drive the mechanically driven feed pump ( 16 ); wherein during normal operation of the drive system ( 9 ) the electrically powered feed pump ( 15 ) in the supply system ( 10 ; 20 ) is configured to deliver lubricant and/or coolant to the components ( 11 , 12 , 13 , 14 ), and wherein, during a special operating mode in which the electrically powered feed pump ( 15 ) is switched off while the drive system ( 9 ) is still operating, the mechanically driven feed pump ( 16 ) alone is configured to supply at least some ( 11 , 14 ) of the components ( 11 , 12 , 13 , 14 ) with lubricant and/or coolant, wherein when driven by the drive output, the mechanically driven feed pump ( 16 ) delivers only a minimum quantity of lubricant and/or coolant that corresponds to a minimum demand required for supplying the lubricant and/or coolant to at least those ( 11 , 14 ) of the components ( 11 , 12 , 13 , 14 ) concerned.
8 . The supply system ( 20 ) according to claim 7 , comprising a clutch ( 21 ) arranged between the mechanically driven feed pump ( 16 ) and the drive output ( 18 ), by means of which clutch the mechanically driven feed pump ( 16 ) can be decoupled from the drive output ( 18 ).
9 . The supply system ( 20 ) according to claim 8 , wherein the clutch ( 21 ) is configured to be controlled as a function of a pressure present in the supply system ( 20 ) and/or actuated by an actor.
10 . The supply system ( 10 ) according to claim 7 , wherein the mechanically driven feed pump ( 16 ) is permanently coupled to the drive output ( 18 ).

Description

RELATED APPLICATIONS This application claims the benefit of and right of priority under 35 U.S.C. § 119 to German Patent Application no. 10 2024 210 553.8, filed on 4 Nov. 2024, the contents of which are incorporated herein by reference in its entirety. FIELD OF THE DISCLOSURE The invention relates to a method for operating a supply system, in which components of a drive system are supplied with a lubricant and/or coolant, wherein during the normal operation of the drive system an electrically powered feed pump is operated and thereby, by way of the electrically powered feed pump, a lubricant and/or coolant in the supply system is delivered to the components, and wherein, during a special operation in which the electrically powered feed pump is switched off while the drive system is still operating, at least some of the components in the supply system are supplied with a lubricant and/or coolant by means of a mechanically driven feed pump. In addition, the invention relates to a supply system by which components of a drive system can be supplied with a lubricant and/or coolant. BACKGROUND In drivetrains, by means of supply systems it is usual in each case for components to be supplied with a lubricant and/or coolant in order to lubricate and/or cool the individual components and/or to operate the individual components by virtue of the supply. In most cases, a supply system is then designed as a hydraulic system in which a hydraulic fluid is supplied, which fluid is usually oil. During the operation of the drive system concerned, to the extent possible, a sufficient supply of the individual components should be ensured at all times. More and more often supply systems comprise electrically powered feed pumps, although in some cases, in addition to the electrically powered feed pump a mechanically driven feed pump is also provided so that in the event of a malfunction or similar, it remains possible to supply at least some of the components by way of the supply system. For example, EP 2 855 928 B1 discloses a supply system for a drive system in the form of a transmission of a wind-power unit. In this case, components in the form of bearings and gearwheels can be supplied with lubricant by the supply system, and for that supply, besides an electrically powered feed pump, a mechanically driven feed pump is also provided. In the context of a method, the supply system of EP 2 855 928 B1 can be operated in such manner that during the normal operation of the transmission, the electrically powered feed pump is supplied with electrical energy and thereby lubricant is delivered to the bearings and gearwheels by the two feed pumps. Furthermore, in a special operational mode in which the operation of the electrically powered feed pump is prevented during the active operation of the transmission because the electrical energy supply has failed, only some of the components, namely, the bearings of the transmission, are supplied with lubricant by the mechanically driven feed pump acting on its own. SUMMARY Starting from the above-mentioned prior art, it is now the purpose of the present invention, in the case of a supply system of a drive system, on one hand to keep losses as small as possible, and on the other hand, to avoid damage to components of the drive system that would otherwise take place owing to insufficient lubricant supply. From a process-technological standpoint, this objective is achieved starting from methods of the present disclosure. In addition, from the equipment standpoint, the objective is achieved by a supply system as disclosed herein. Advantageous further developments will be apparent in light of the present disclosure. According to the present disclosure, in a method for operating a supply system, components of a drive system are supplied with lubricant and/or coolant. For this, during normal operation of the drive system an electrically powered feed pump is operated and thereby, by way of the electrically powered feed pump, in the supply system lubricant and/or coolant is/are delivered to the components. In contrast, during a special operating mode in which while the drive system is operating the electrically powered feed pump is switched off, by means of the supply system at least some of the components are supplied with lubricant and/or coolant by means of a mechanically driven feed pump. Thus, during the normal operation of the drive system the supply system is operated in such manner that the components are supplied by an electrically powered feed pump which, in the supply system, is supplied with electrical energy for that purpose and thereby delivers lubricant and/or coolant to the components. On the other hand, the special operating mode takes place if, during the active operation of the drive system, the electrically powered feed pump is not operated so that then the electrically powered feed pump does not deliver any lubricant and/or coolant. Instead, during the special operating mode only