US 12,305,544 B2
Hydraulic drive for accelerating and braking components
Patrik Soltic, Uhwiesen (CH); Andyn Omanovic, Uster (CH); and Wolfgang Schneider, Thun (CH)
Assigned to EMPA Eidgenössische Materialprüfungs-und Forschungsanstalt, Dubendorf (CH); and Wolfgang Schneider Ingenieurburo, Thun (CH)
Appl. No. 18/268,876
Filed by EMPA Eidgenössische Materialprüfungs-und Forschungsanstalt, Dubendorf (CH); and Wolfgang Schneider Ingenieurburo, Thun (CH)
PCT Filed Dec. 20, 2019, PCT No. PCT/EP2019/086856
§ 371(c)(1), (2) Date Jun. 21, 2023,
PCT Pub. No. WO2021/121639, PCT Pub. Date Jun. 24, 2021.
Prior Publication US 2024/0035400 A1, Feb. 1, 2024
Int. Cl. F01L 9/10 (2021.01); F01L 9/40 (2021.01)
CPC F01L 9/10 (2021.01) [F01L 9/40 (2021.01)] 19 Claims
OG exemplary drawing
 
1. A hydraulic drive for accelerating and braking dynamically moving components of an internal combustion engine, the hydraulic drive comprising:
a double-acting working cylinder defining a driving chamber and a braking chamber;
a drive piston configured to slide within the double-acting working cylinder so as to engage at least one gas exchange valve, the drive piston including an opening pressure acting surface in the driving chamber, and a closing pressure acting surface in the braking chamber;
at least one restoring energy accumulator configured to impart a biasing force on the at least one gas exchange valve;
at least one drive pressure reservoir configured to provide a drive pressure of a hydraulic pressure medium at a first pressure;
at least one base pressure reservoir configured to store the hydraulic pressure medium at a base pressure which is less than the first pressure;
at least one inflow control valve configured to selectively connect the at least one drive pressure reservoir to the driving chamber so as to open the at least one gas exchange valve; and
at least one drain control valve configured to selectively connect the driving chamber to the at least one base pressure reservoir,
wherein the drive piston further includes at least one control edge corresponding to an inflow opening of the double-acting working cylinder such that, when a cutting stroke of the drive piston is reached, the at least one control edge (i) prevents an inflow of the drive pressure into the driving chamber, and/or (ii) prevents a low-loss outflow of the hydraulic pressure medium from the braking chamber to the at least one base pressure reservoir,
wherein a remaining hydraulic drive force of the hydraulic pressure medium drops to zero or reverses direction when the cutting stroke is reached, and
wherein the at least one base pressure reservoir is connected to the braking chamber via at least one first check valve which opens in a direction towards the braking chamber, and closes in a direction towards the at least one base pressure reservoir.