Axle driving apparatus

• US 6,073,443 A
• Filed: 08/06/1998
• Issued: 06/13/2000
• Est. Priority Date: 08/06/1997
• Status: Expired due to Term

• Current Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd. (Yanmar Holdings Co., Ltd.)
• Original Assignee: Kanzaki Kokyukoki Mfg. Co., Ltd. (Yanmar Holdings Co., Ltd.)
• Inventors: Ishii, Norihiro, Okada, Hideaki
• Primary Examiner(s): NGUYEN, HOANG M
• Application Number:
  US09/129,957
• Time in Patent Office: 677 Days
• Field of Search: 60/487, 60/488, 60/489, 60/456
• US Class Current: 60/456
• CPC Class Codes: F16H 39/14 with cylinders carried in rotary cylinder blocks or cylinder-bearing members
• CPC Class Codes: F16H 57/027 characterised by means for venting gearboxes, e.g. air breathers
• CPC Class Codes: F16H 57/0412 Cooling or heating; Control of temperature
• CPC Class Codes: F16H 57/0415 Air cooling or ventilation; Heat exchangers; Thermal insulations
• CPC Class Codes: F16H 57/0421 on or within the casing, e.g. shields or baffles for collecting lubricant, tubes, pipes, grooves, channels or the like

Abstract

A hydrostatic transmission (HST) including a hydraulic pump is contained in a housing having upper and lower housings. An input shaft of the hydraulic pump projects outward from the upper housing. A cooling fan is provided on an upper end of the input shaft. A conduit is disposed within an area between the fan and the upper housing. The conduit extends between first and second couplings and is in communication with an oil sump formed in the housing. A pumping device, which rotates with the input shaft, is disposed within the second coupling for forcedly circulating oil between the conduit and the sump. Alternatively, a reservoir is disposed on an outer wall of the housing forming a second oil sump. A level of oil in the second oil sump is lower than a level of oil in the oil sump formed in the housing. The second oil sump communicates with the atmosphere whereas the oil sump formed in the housing is separated from the atmosphere. A siphon communicates both sumps with each other. The driving apparatus may incorporate either the conduit, the reservoir, or both the conduit and the reservoir.

Claims

1. An axle driving apparatus comprising:

a housing having an oil sump formed therein;

a hydrostatic transmission (HST) contained in said housing and immersed in said oil sump;

an input shaft of said HST projecting outwardly from said housing;

a cooling fan provided on said input shaft external to said housing;

an oil passage, wherein each end of said passage is in fluid communication with said oil sump, said oil passage being disposed in an area of said housing which is air-cooled by said cooling fan; and

a pumping means disposed between said oil passage and said oil sump, said pumping means being driven by said input shaft, wherein said pumping means circulates oil between said oil sump and said oil passage.

2. An axle driving apparatus according to claim 1, wherein said oil passage comprises a pair of couplings and a conduit connecting said couplings with each other, wherein said pair of couplings are in communication with said oil sump by a pair of openings in said housing, respectively.

3. An axle driving apparatus according to claim 1, wherein said oil passage comprises a channel formed in a plate member disposed on said housing.

4. An axle driving apparatus according to claim 1, further comprising a coupling interposed between said oil passage and said oil sump, wherein said pumping means is disposed within an interior of said coupling.

5. An axle driving apparatus comprising:

a housing having a first oil sump formed therein;

a hydrostatic transmission (HST) contained in said housing and immersed in said first oil sump;

an input shaft of said HST projecting substantially vertically outwardly from said housing;

a cooling fan provided on said input shaft external to said housing; and

a second oil sump disposed underneath said cooling fan for regulating the volume of oil in said first oil sump such that said second oil sump is partially overlapped by said cooling fan, wherein oil flows in both directions between said first and second oil sumps.

6. An axle driving apparatus according to claim 5, wherein an oil level of said second oil sump is lower than that of said first oil sump.

7. An axle driving apparatus comprising:

a housing;

a first oil sump formed in said housing, said first oil sump being separated from the atmosphere;

a hydrostatic transmission (HST) contained in said housing and immersed in said first oil sump;

a second oil sump in communication with the atmosphere for regulating the volume of oil in said first oil sump; and

a siphon allowing oil to flow in both directions between said first and second oil sumps.

8. An axle driving apparatus according to claim 7, further comprising:

an input shaft for driving said HST, said input shaft projecting outwardly from said housing; and

a cooling fan provided on said input shaft exterior of said housing, wherein said second oil sump is disposed in an air-cooled area of said cooling fan.

9. An axle driving apparatus according to claim 7, wherein an oil level of said second oil sump is lower than that of said first oil sump.

10. An axle driving apparatus comprising

a housing;

a hydrostatic transmission (HST) contained in said housing;

an oil reservoir disposed on an outer wall of said housing for regulating the volume of oil in said housing, wherein said reservoir is provided with a first fixture and said housing is provided with a second fixture corresponding to said first fixture; and

a coupling disposed above said first fixture which connects to the interior of said housing to provide fluid flow between said oil reservoir and an interior of said housing.

11. An axle driving apparatus according to claim 10, wherein one of said first fixture and said second fixture is concave and the other of said first fixture and said second fixture is convex, wherein said second fixture is provided on an elastic plate for engaging with said first fixture.

12. An axle driving apparatus comprising:

a housing;

a first oil sump formed in said housing;

a hydrostatic transmission (HST) contained in said housing, said HST being immersed in said first oil sump;

an input shaft of said HST projecting outwardly from said housing;

a cooling fan provided on said input shaft external to said housing;

an oil passage in communication with said first oil sump, said oil passage being disposed in an air-cooled area of said cooling fan external to said housing;

a pumping means disposed between said oil passage and said first oil sump, said pumping means being driven by said input shaft, wherein said pumping means circulates oil between said oil sump and said oil passage;

second oil sump in communication with the atmosphere for regulating the volume of oil in said first oil sump; and

a siphon allowing oil to flow in both directions between said first and second oil sumps.

13. An axle driving apparatus according to claim 12, wherein said second oil sump is disposed in an area of said housing which is air-cooled by said cooling fan.

14. An axle driving apparatus according to claim 12, wherein an oil level of said second oil sump is lower than an oil level of said first oil sump.

15. An axle driving apparatus according to claim 12, wherein said oil passage further comprises a pair of couplings and a conduit connecting said couplings with each other, wherein said pair of couplings are in communication with said oil sump by a pair of openings in said housing, respectively, and one of said couplings is connected to said siphon.

16. An axle driving apparatus according to claim 12, wherein said oil passage is a channel formed in a plate member disposed on said housing.

17. An axle driving apparatus comprising:

a housing forming an oil sump therein;

a hydrostatic transmission (HST) contained in said housing and immersed in said oil sump;

an input shaft of said HST projecting outwardly from said housing;

a cooling fan provided on said shaft external to said housing;

an oil passage in communication with said oil sump, said oil passage being disposed in an area of said housing which is air-cooled by said cooling fan;

a pumping means disposed between said oil passage and said oil sump, said pumping means being driven by said input shaft, wherein said pumping means circulates oil between said oil sump and said oil passage;

an oil reservoir disposed on an outer wall of said housing for regulating the volume of oil in said housing;

a first fixture provided on said reservoir;

a second fixture corresponding to said first fixture, provided on said housing; and

a siphon providing communication between said oil sump and the interior of said reservoir.

18. An axle driving apparatus according to claim 17, wherein said reservoir is disposed in an area of said housing which is air-cooled by said cooling fan.

19. An axle driving apparatus according to claim 17, wherein a level of oil in said oil reservoir is lower than a level of oil in said oil sump.

20. An axle driving apparatus according to claim 17, wherein said oil passage further comprises a pair of couplings and a conduit connecting said couplings with each other, wherein said pair of couplings are in communication with said oil sump by a pair of openings in said housing, respectively, and one of said couplings is connected to said siphon.

21. An axle driving apparatus according to claim 17, wherein said oil passage is a channel formed in a plate member disposed on said housing.