US 12,215,484 B2
Hydraulic motor unit
Hiromi Nagayama, Tokyo (JP)
Assigned to NABTESCO CORPORATION, Tokyo (JP)
Filed by Nabtesco Corporation, Tokyo (JP)
Filed on Nov. 3, 2023, as Appl. No. 18/501,669.
Claims priority of application No. 2022-196285 (JP), filed on Dec. 8, 2022.
Prior Publication US 2024/0191475 A1, Jun. 13, 2024
Int. Cl. E02F 9/22 (2006.01); F15B 11/044 (2006.01); F16H 61/4157 (2010.01); F16H 61/421 (2010.01); F16H 61/423 (2010.01)
CPC E02F 9/2285 (2013.01) [E02F 9/2228 (2013.01); E02F 9/2253 (2013.01); E02F 9/2289 (2013.01); F15B 11/0445 (2013.01); F16H 61/4157 (2013.01); F16H 61/421 (2013.01); F16H 61/423 (2013.01)] 6 Claims
OG exemplary drawing
 
6. A hydraulic motor unit, comprising:
a hydraulic motor having an output shaft and a brake for braking the output shaft;
a two-speed switching valve for switching a speed of the output shaft; and
a brake actuator for releasing braking of the brake,
wherein the hydraulic motor is connected to a first channel and a second channel each conveying a hydraulic fluid for driving by a hydraulic pump, and the hydraulic motor is connected in a closed circuit with the hydraulic pump to form an HST circuit, and
wherein the hydraulic motor unit further comprises:
a low-pressure selector valve connected to the first channel and the second channel and configured to select a low-pressure hydraulic fluid under a lower pressure from the hydraulic fluids conveyed by the first channel and the second channel; and
one proportional valve connected to a third channel downstream of the low-pressure selector valve and housed inside the HST circuit, and
wherein the hydraulic fluid under a lower pressure is branched and supplied to the brake actuator and the two-speed switching valve through a pilot channel connected to the proportional valve.