# US 10,502,302 B2 · Hydraulic limited differential slip > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,502,302 B2 - Document ID: US10502302B2 - Status: Granted - Kind: B2 - Application number: 15/870,934 - Filed: 2018-01-13 - Published: 2018-11-22 - Granted: 2019-12-10 - Earliest claimed: 2017-05-20 - Applicants: Amir Aghabeygi Saravani - Inventors: Amir Aghabeygi Saravani - Web page: https://patentgrep.com/patent/US10502302B2 ## CPC - F16H 48/27: using internally-actuatable fluid pressure, e.g. internal pump types - F04C 2/18: with similar tooth forms (F04C2/16 takes precedence) - F04C 14/24: characterised by using valves controlling pressure or flow rate, e.g. discharge valves {or unloading valves}(F04C14/10 takes precedence) - F16H 48/08: comprising bevel gears - F16H 48/32: using fluid pressure actuators - F16H 48/38: Constructional details (the outer casing comprising the differential and supporting input and output shafts F16H57/037) - F04C 2/084: {Toothed wheels} - F16H 2048/385: {of the ring or crown gear} - F16H: GEARING - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS ## Abstract A positive displacement pump for hydraulic limited differential comprises a first external gear and a second external gear juxtaposed inside a casing, wherein one or more outer teeth sections of the external gear are tangential to the casing. The casing is filled with a fluid via an opening and sealed using a plug member on both sides to define a fluid tight sealing configuration and a pair of shafts are configured to couple the first external gear and the second external gear. The clockwise rotation of the first external gear is configured to drive the second external gear in counter clockwise direction in the casing to allow the movement of the fluid inside the casing via one or more countersinks to create a pressure difference for internal circulation of the fluid in the permitted gaps to control the differential slip for increasing the stability of the driving vehicle. ## Claims ### Claim 1 A positive displacement pump for hydraulic limited differential in a vehicle, comprises: a first external gear and a second external gear juxtaposed inside a casing, wherein one or more outer teeth sections of the external gears are tangential to the casing; a crown wheel is configured to encompass the casing and takes a receiving force from a pinion to drive axle shafts of the vehicle via the positive displacement pump; wherein the casing is filled with a fluid via an opening and sealed using a plug member on both sides to define a fluid tight sealing configuration; a pair of shafts are configured to couple the first external gear and the second external gear, wherein the clockwise rotation of the first external gear is configured to drive the second external gear in counter clockwise direction in the casing to allow movement of the fluid inside the casing; and a channel is disposed in the casing configured to connect one or more countersinks created on all sides of the first external gear and the second external gear respectively, wherein the movement of the fluid in the casing creates a pressure difference in the countersinks to circulate the fluid internally via permitted gaps and slips to control a differential slip. ### Claim 2 (depends on 1) The positive displacement pump of claim 1, wherein the fluid is an oil having a predetermined viscosity based on a configuration of the pump. ### Claim 3 (depends on 1) The positive displacement pump of claim 1, wherein the fluid is configured to move from a high-pressure countersink to a low-pressure countersink to create the pressure difference to cause internal circulating of the fluid during the movement of the vehicle. ### Claim 4 (depends on 1) The positive displacement pump of claim 1, wherein the amount of fluid movement from a high-pressure countersink to a low-pressure countersink is directly proportional to the rate of the differential slip in the vehicle. ### Claim 5 (depends on 1) The positive displacement pump of claim 1, wherein an inlet and an outlet in the casing for the movement of the fluid is closed to control the differential slip based on the internal circulation of fluid by the pump. ### Claim 6 (depends on 1) The positive displacement pump of claim 1, wherein a coupling is configured to seal the opening to caulk the space inside the casing. ### Claim 7 (depends on 1) The positive displacement pump of claim 1, wherein a pair of side gears mounted on a shaft extending from the first external gear and the second external gear and a pair of support gears are mounted on the axle shafts of the vehicle. ### Claim 8 (depends on 7) The positive displacement pump of claim 7, wherein one or more support gears are positioned concentrically with the crown wheel. ### Claim 9 (depends on 1) The positive displacement pump of claim 1, wherein the axle shafts of the vehicle are connected to support gears for transferring a traction force for differential adjustment to control the differential slip in the vehicle. ### Claim 10 (depends on 1) The positive displacement pump of claim 1, wherein the opening in the casing defines an entry and bleeding path for a flow of the fluid inside the casing. ### Claim 11 (depends on 1) The positive displacement pump of claim 1, wherein the channel is configured to connect a fluid inlet and outlet in the casing to define a closed circuit. ### Claim 12 (depends on 1) The positive displacement pump of claim 1, further comprises a valve disposed in the channel of a closed circuit configured to control the movement of the fluid inside the casing. ### Claim 13 (depends on 1) The positive displacement pump of claim 1, wherein the differential in the vehicle is locked when the internal circulation of the fluid in the pump is minimum. ### Claim 14 (depends on 1) The positive displacement pump of claim 1, wherein the differential in the vehicle is configured to be open when the channel is open for movement of the fluid based on the internal circulation of fluid by the pump. ### Claim 15 A positive displacement pump for hydraulic limited differential in a vehicle, comprises: a first external gear and a second external gear juxtaposed inside a casing, wherein one or more outer teeth sections of the external gears are tangential to the casing; a crown wheel is configured to encompass the casing and takes a receiving force from a pinion to drive axle shafts of the vehicle via the positive displacement pump, wherein the axle shafts are configured to couple the first external gear and the second external gear; a pair of side gears mounted on a shaft extending from the first external gear and the second external gear and a pair of support gears are mounted on the axle shafts of the vehicle, wherein the support gears are coupled to the first external gear and the second external gear for concentric alignment with the crown wheel; wherein the casing is filled with a fluid via an opening and sealed using a plug member on both sides to define a fluid tight sealing configuration; wherein a clockwise rotation of the first external gear is configured to drive the second external gear in counter clockwise direction in the casing to allow movement of the fluid inside the casing; and a high-pressure countersink and a low-pressure countersink are created on all sides of the first external gear and the second external gear respectively, wherein movement of the fluid in the casing via a channel from the high-pressure countersink to the low-pressure countersink creates a pressure difference to circulate the fluid internally via permitted gaps and slips to control a differential slip. ### Claim 16 (depends on 15) The positive displacement pump of claim 15, wherein the side gears and support gears are enclosed by a shell member and rotatably attached to the plug member of the casing. ### Claim 17 (depends on 15) The positive displacement pump of claim 15, wherein a valve disposed in the channel of to a closed circuit is electronically controlled to selectively adjust the movement of the fluid inside the casing to limit the differential slip. ### Claim 18 (depends on 17) The positive displacement pump of claim 17, wherein the valve is configured to limit the differential slip in at least one of a manual and an automatic method depending on the stability requirements of the vehicle.