Hydromechanical transmission with double sump gear unit housing

Patent metadata

Field	Value
Publication number	US-9453566-B2
Application number	US-201414529249-A
Country	US
Kind code	B2
Filing date	Oct 31, 2014
Priority date	May 2, 2012
Publication date	Sep 27, 2016
Grant date	Sep 27, 2016

Abstract

A hydromechanical transmission 11 includes a hydraulic unit 23 and a gear unit 24 . The gear unit 24 includes a first gear unit housing 29 a defining a first sump 37 a having a first set of gears 71 . A second gear unit housing 29 b defines a substantially smaller second sump 37 b having a second set of gears 78, 79 . An input shaft 62 extends longitudinally into the first sump 37 a , and an output shaft 63 extends longitudinally from the second sump 37 b . The longitudinal axes of the input and output shafts are substantially coaxial. A first hydraulic pump motor unit drive shaft 44 extends into the first sump 37 a and is drivingly connected with the first set of gears, and a second hydraulic pump motor unit drive shaft 45 extends through the first sump 37 a and into the second sump 37 b and is drivingly connected with the second set of gears.

First claim

The invention claimed is:

1. A hydromechanical transmission comprising:
a first gear unit housing and a second gear unit housing, each of the housings having walls, the walls of the first and second housings being connected together, the walls of the first housing defining a first sump, the walls of the second housing defining a second sump,
a first set of rotatable gears disposed in the first sump,
a second set of rotatable gears disposed in the second sump, each of the sets of rotatable gears including at least two gears,
an input drive shaft extending longitudinally into the first sump and being rotatably connected to the first set of rotatable gears,
an output drive shaft extending longitudinally out of the second sump and being rotatably connected to the second set of gears,
first and second hydraulic pump motor unit drive shafts which extend longitudinally into the first sump,
wherein the longitudinal axes of the input and output drive shafts are substantially coaxial,
the first hydraulic pump motor unit drive shaft extends longitudinally into and through the first sump and into the second sump and is rotatably supported by a bearing in a wall of the first sump, and
a first gear of the second set of gears is rotatably connected to the first hydraulic pump motor unit drive shaft, and a second gear of the second set of gears is rotatably connected to the output drive shaft, the said first and second gears drivingly engaging one another.

2. A hydromechanical transmission as set forth in claim 1 , in which at least one wall of the first and second housings is a common wall that defines the first sump and the second sump, the common wall including a hydraulic pump motor unit opening, and the second hydraulic pump motor unit drive shaft extending through the opening.

3. A hydromechanical transmission as set forth in claim 1 , in which the second hydraulic pump motor unit drive shaft extends longitudinally through the first sump and into the second sump.

4. A hydromechanical transmission as set forth in claim 1 , in which the second hydraulic pump motor unit drive shaft is rotatably supported by a bearing in a wall of the first sump and by a bearing in a wall of the second sump.

5. A hydromechanical transmission as set forth in claim 1 , in which the first hydraulic pump motor unit drive shaft is driving connected to the first set of rotatable gears in the first sump, and the second hydraulic pump motor unit drive shaft is drivingly connected to the second set of rotatable gears in the second sump.

6. A hydromechanical transmission as set forth in claim 1 , in which the first set of rotatable gears includes planetary gear components disposed in the first sump, the first mentioned input drive shaft is rotatably connected to one of the planetary gear components, and the output drive shaft is rotatably connected to another of the planetary gear components.

7. A hydromechanical transmission as set forth in claim 6 , in which the output drive shaft extends longitudinally from the planetary gear components in the first sump through the second sump.

8. A hydromechanical transmission as set forth in claim 6 , in which:
the first hydraulic pump motor unit drive shaft is rotatably connected to another of the planetary gear components,
at least one wall of the first and second housings is a common wall that defines the first sump and the second sump,
the longitudinal axes of the input shaft and output shaft extend through the common wall, and the longitudinal axes of the pump motor unit drive shafts are laterally offset relative to the longitudinal axes of the input and output shafts,
the longitudinally aligned shaft openings in the common wall and in other walls of the first and second sumps, and the input shaft and output shaft, extend through the shaft openings, and
bearings are provided in the shaft openings which support the input shaft and the output shaft.

9. A hydromechanical transmission as set forth in claim 1 , in which the second hydraulic pump motor unit drive shaft is supported by a bearing in a wall of the first sump and by a bearing in a wall of the second sump.

10. A hydromechanical transmission as set forth in claim 1 , which includes:
a hydraulic unit housing connected to the first gear unit housing,
a prime mover drive shaft extending longitudinally into the hydraulic unit housing, the longitudinal axis of the prime mover drive shaft being coaxial with the input shaft and the output shaft.

11. A hydromechanical transmission as set forth in claim 10 , including first and second hydraulic pump motor units disposed in the hydraulic unit housing.

12. A hydromechanical transmission as set forth in claim 8 , in which the first set of rotatable gears has a stationary condition and a rotating condition, the second set of rotatable gears has a stationary condition and a rotating condition, at least one opening extends through the common wall and establishes a fluid flow path between the first sump and the second sump, the first sump is partially filled with a liquid lubricant to a predetermined first sump fill level, the second sump is partially filled with a liquid lubricant to a second sump predetermined fill level, the first and second sump fill levels are substantially the same when the second rotatable gear set is in its stationary condition, and the second sump fill level is substantially vertically beneath the first sump fill level when the second rotatable gear set is in its rotating condition.

13. A hydromechanical transmission as set forth in claim 12 , in which the first sump has a volume of liquid lubricant, the second sump has a volume of liquid lubricant, and the volume of liquid lubricant in the second sump is no greater than about 30 percent of the volume of liquid lubricant in the first sump when the second gear set is in its stationary condition.

14. A hydromechanical transmission as set forth in claim 12 , in which:
at least two openings extend between and establish a fluid flow path between the first sump and the second sump, the openings being in the common wall,
a channel provides a fluid flow path between the openings, one of the rotatable gears of the second set of gears being disposed adjacent the channel, and
rotation of the one of the rotatable gears when the second gear set is in its rotating condition pumps fluid through the channel between the first and second openings.

15. A hydromechanical transmission as set forth in claim 1 , including at least one longitudinally extending ledge in the second sump, a wall of the first housing having an opening formed in it which extends longitudinally between the first sump and the second sump, the ledge being adjacent the opening, arranged so that rotation of a gear in the second sump splashes liquid lubricant on to the ledge so that liquid lubricant flows from the ledge through the other opening and into the first sump.

16. A hydromechanical transmission as set forth in claim 15 , including bearings in the shaft openings supporting the input shaft and the output shaft.

17. A hydromechanical transmission comprising:
a first gear unit housing and a second gear unit housing, each of the housings having walls, the walls of the first and second housings being connected together, the walls of the first housing defining a first sump, the walls of the second housing defining a second sump,
a first set of rotatable gears disposed in the first sump,
a second set of rotatable gears disposed in the second sump, each of the sets of rotatable gears including at least two gears,
an input drive shaft exten

Assignees

• Parker Hannifin Corp

Inventors

• Loeffler John
• Paisley Daniel
• Imam Nabil
• Rommel Matthew

Classifications

• Y10T29/49464

  Assembling of gear into force transmitting device · CPC title

• F16D1/06

  for attachment of a member on a shaft or on a shaft-end (attachment of marine propellers on shafts B63H23/34) · CPC title

• F16H61/44

  with more than one pump or motor in operation · CPC title

• Y10T403/7026

  Longitudinally splined or fluted rod · CPC title

• F16H47/04 Primary

  the mechanical gearing being of the type with members having orbital motion · CPC title