Patent · US Active

Work machine

US12371880B2 · kind B2 · utility

0Cited by
0References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 7, 2023
Grant dateJul 29, 2025
Priority date
Expiry dateFeb 7, 2043

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF15B2211/8609
  • WIPO fieldCivil engineering
  • WIPO sectorOther fields

Abstract

A work machine includes: a hydraulic actuator; a closed-circuit pump that is connected to the hydraulic actuator in a closed circuit, and supplies and discharges a hydraulic working fluid to and from the hydraulic actuator; an open-circuit pump that is connected to the hydraulic actuator in an open circuit, and supplies the hydraulic working fluid to the hydraulic actuator; a charge pump; a charge flow path that introduces the hydraulic working fluid delivered from the charge pump to the closed circuit; an excess fluid discharging device that discharges an excess hydraulic working fluid of the closed circuit to the charge flow path; and a controller that controls a delivery capacity of the closed-circuit pump and a delivery capacity of the open-circuit pump. The controller increases the delivery capacity of the open-circuit pump, or reduces the delivery capacity of the closed-circuit pump when a state of a pressure of the charge flow path has transited to be lower than a predetermined pressure threshold from equal to or higher than the predetermined pressure threshold, or when a state of the work device has transited to a state of performing the excavation work from a state of not-…

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.