The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 12, 2024
Filed:
Jul. 29, 2021
Kawasaki Jukogyo Kabushiki Kaisha, Kobe, JP;
KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe, JP;
Abstract
A hydraulic excavator drive system includes: a first pump connected to a head-side chamber of a boom cylinder; and a second pump that supplies hydraulic oil to at least one of an arm cylinder or a bucket cylinder. The first pump is driven by an electric motor. The drive system further includes: a first switching valve located on a rod-side line; and a second switching valve located on a relay line. The first switching valve opens the rod-side line at a boom raising operation, but blocks the rod-side line except at the boom raising operation. The second switching valve blocks the relay line at the boom raising operation, but opens the relay line at a vehicle body lifting operation.