5 WE CLAIM:
1. A sealing mechanism (100) for sealing against leakage of fluid under pressure in a
hydraulic drive, the hydraulic drive comprising
a housing (101);
a phase terminal (102) extending from the hydraulic drive; and
10 the sealing mechanism (100) between the phase terminal and the housing, wherein the
sealing mechanism (100) comprises:
a hollow plug (103) comprising a neck and externally threaded grooves, wherein
the plug (103) is disposed in contact with the phase terminal (102);
a first O-ring (104) disposed within an annular groove on the phase terminal
15 (102), between the phase terminal (102) and the plug (103);
a backup ring (106) disposed in contact with the first O-ring (104), within the
annular groove;
a second O-ring (105) disposed within the externally threaded grooves of the
hollow plug (103) below the plug neck, in contact with the housing (101); and
20 a circlip (107) disposed within a groove on the plug (103);
wherein the leakage of fluid under pressure is stopped at multiple stages.
2. The sealing mechanism (100) as claimed in claim 1 wherein the hollow plug (103) is a
pass-through plug that is configured to secure the phase terminal (102) to the housing
25 (101).
3. The sealing mechanism (100) as claimed in claim 1 wherein the hollow plug (103) is a
polymeric, fluid-impervious insulator having an end opening for the phase terminal.
30 4. The sealing mechanism (100) as claimed in claim 1 wherein the first O-ring (104) and
backup ring (106) are provided against the phase terminal (102) as a first seal for sealing
against leakage of fluid under pressure, internally.
5. The sealing mechanism (100) as claimed in claim 1 wherein the fastening of the second
35 O-ring (105) in the plug to the housing provides a second seal for sealing against leakage
of fluid under pressure, externally.
14
5 6. The sealing mechanism (100) as claimed in claim 1 wherein the first and second O-rings
(104,105) are fabricated from polymeric materials such as fluoroelastomers and
fluorosilicones.
7. The sealing mechanism (100) as claimed in claim 1 wherein the backup ring secures the
10 first O-ring (104) in the annular groove of the phase terminal (102).
8. The sealing mechanism (100) as claimed in claim 1 wherein the circlip is a semi-flexible
metal ring with open ends, fabricated from stainless steel or spring steel.
9. The sealing mechanism (100) as claimed in claim 1 wherein the circlip is configured to
secure the plug (103) in place and prevent it from sliding in the sealing arrangement.
15 10. The sealing mechanism (100) as claimed in claim 1 wherein the mechanism can
withstand a high pressure of up to 130 bar.
11. The sealing mechanism (100) as claimed in claim 1 wherein the mechanism can
withstand temperatures up to 120oC.
12. The sealing mechanism (100) as claimed in claim 1, wherein the fluid utilized is a high20 pressure coolant for the purpose of heat dissipation in PMSM systems.
13. A method of operation of a sealing mechanism (100) for sealing against leakage of fluid
under pressure in a hydraulic drive comprising a phase terminal (102), and a housing
(101), the method comprising steps of:
securing the phase terminal (102) in a hollow plug (103) in the housing (101);
25 disposing of a first O-ring (104) and a backup ring (106) in an annular groove
on the phase terminal (102) to stop leakage of fluid internally, at the phase
terminal (102);
fastening of a second O-ring (105) in an externally threaded groove on the plug
(103) to the housing (101) to stop leakage of fluid externally, at the housing
30 (101); and
securing a circlip (107) within a groove on the housing (101) to keep the plug
(103) in position in the sealing mechanism (100);
wherein the leakage of fluid under pressure is stopped at multiple stages from
the housing (101) by the sealing mechanism (100).
35
15
5 14. A hydraulic drive, comprising the sealing mechanism (100) in accordance with claims
1-12.