US 12,257,989 B2
Accumulator piston device
Marcus Ertle, Immenstadt (DE); Alexander Bareiss, Immenstadt (DE); Juergen Reiner, Gestratz (DE); and Michael Loeffler, Oberstaufen (DE)
Assigned to Robert Bosch GmbH, Stuttgart (DE)
Appl. No. 18/562,441
Filed by Robert Bosch GmbH, Stuttgart (DE)
PCT Filed Mar. 3, 2022, PCT No. PCT/EP2022/055366
§ 371(c)(1), (2) Date Nov. 20, 2023,
PCT Pub. No. WO2022/248090, PCT Pub. Date Dec. 1, 2022.
Claims priority of application No. 10 2021 205 371.8 (DE), filed on May 27, 2021.
Prior Publication US 2024/0239325 A1, Jul. 18, 2024
Int. Cl. B60T 17/06 (2006.01); F15B 1/04 (2006.01)
CPC B60T 17/06 (2013.01) [F15B 1/04 (2013.01)] 13 Claims
OG exemplary drawing
 
1. An accumulator piston device for a pressure medium accumulator of a hydraulic unit for brake pressure control in an electronically pressure-controllable power brake system of an electrically driven motor vehicle, comprising:
an accumulator piston, which comprises a sleeve-shaped piston shaft and a piston crown which closes the sleeve-shaped piston shaft at one of its ends,
wherein the piston shaft is divided in a direction of a longitudinal piston axis into successive shaft portions of different outer diameters,
wherein outer diameters of the successive shaft portions increase in respective steps starting from a first shaft portion, on which the piston crown is arranged, the first shaft portion defining a first outer diameter that is a smallest outer diameter of the successive shaft portions,
wherein a first step of the respective steps between the first shaft portion and a subsequent shaft portion of the successive shaft portions in the longitudinal axis of the piston forms an abutment shoulder for a seal of the accumulator piston device arranged on the first shaft portion, and
wherein the accumulator piston includes a first guide ring on the first shaft portion, the first guide ring configured to surround the piston shaft, and
wherein a maximum diameter of the crown is equal to or less than the first outer diameter of the first shaft portion.