Rotary pump with telescoping rotor sections that vary the flow rate

1 . A pump for an aircraft engine, comprising:

a housing including a static wall, a peripheral wall extending from the static wall around an axis, and a movable wall movable along the axis towards and away from the static wall, the movable wall in sealing contact with the peripheral wall;

the static wall, the peripheral wall, and the movable wall defining therebetween a rotor cavity communicating with an inlet and an outlet of the housing;

an input shaft extending through the housing and parallel to the axis;

a rotor drivingly engaged by the input shaft and movably contained within the rotor cavity of the housing for orbital revolutions around the axis, the rotor having two sections axially telescopically connected to one another and both extending between two apexes in sealing contact with the peripheral wall of the housing;

an actuator operatively connected to the movable wall of the housing and operable to displace the movable wall along the axis and relative to the static wall; and

a biasing member operatively connected to the two sections of the rotor to bias the two sections away from one another to follow a movement of the movable wall.

2 . The pump of claim 1 , wherein the two sections include a male section and a female section each defining a respective one of two rotor end walls, the male section defining a first male curved wall and a second male curved wall both extending between the two apexes, the female section defining a first female curved wall and a second female curved wall both extending between the two apexes, the first female curved wall defining a slot, the first male curved wall slidably received within the slot.

3 . The pump of claim 2 , wherein the first male curved wall has a thickness being less than that of the second male curved wall such that a distance between the two apexes is constant along an axial height of the rotor relative to the axis.

4 . The pump of claim 3 , wherein an outer face of the first female curved wall and an outer face of the second male curved wall are flush at the two apexes.

5 . The pump of claim 1 , comprising bearings disposed between two end walls of the rotor and both of the movable wall and the static wall of the housing.

6 . The pump of claim 5 , wherein the bearings are balls rollingly received within grooves defined by the two end walls.

7 . The pump of claim 1 , wherein the movable wall defines an annular groove, a sealing member received within the annular groove, the sealing member abutting the peripheral wall of the housing.

8 . The pump of claim 1 , wherein the housing further include a cover located opposite the static wall, the movable wall movable towards and away from the cover.

9 . The pump of claim 8 , wherein the actuator is located between the cover and the movable wall.

10 . An aircraft engine comprising:

a thermal engine drivingly engaging an engine shaft; and

a fluid system for circulating a fluid to a component, the fluid system having a pump fluidly connecting a reservoir of the fluid to the component, the pump having:

a housing having an inlet fluidly connected to the reservoir and an outlet fluid connected to the component, the housing including a static wall, a peripheral wall extending from the static wall around an axis, and a movable wall in sealing contact with the peripheral wall;

the static wall, the peripheral wall, and the movable wall defining a rotor cavity therebetween, the rotor cavity fluidly connected to the inlet and the outlet;

a rotor drivingly engaged by the engine shaft and movably contained within the rotor cavity for orbital revolutions around the axis, the rotor having two sections axially movable relative to one another and both extending between two apexes in sealing contact with the peripheral wall of the housing during the orbital revolutions, the rotor having a volume being variable with movements of the two sections relative to one another;

an actuator operatively connected to the movable wall of the housing and operable to displace the movable wall along the axis and relative to the static wall; and

a biasing member operatively connected to the two sections of the rotor to bias the two sections away from one another to follow a movement of the movable wall.

11 . The aircraft engine of claim 10 , comprising a controller operatively connected to the actuator, the controller having a processing unit and a computer-readable medium operatively connected to the processing unit and having instructions stored thereon executable by the processing unit to:

determine that a flow rate of the fluid outputted by the pump is different than a desired flow rate of the component; and

adjust the flow rate of the fluid outputted by the pump to reach the desired flow rate by causing the actuator to move the movable wall of the housing to vary a volume of the rotor cavity.

12 . The aircraft engine of claim 10 , wherein the two sections include a male section and a female section each defining an end wall of the rotor, the male section defining a first male curved wall and a second male curved wall both extending between the two apexes, the female section defining a first female curved wall and a second female curved wall both extending between the two apexes, the first female curved wall defining a slot, the first male curved wall slidably received within the slot.

13 . The aircraft engine of claim 12 , wherein the first male curved wall has a thickness being less than that of the second male curved wall such that a distance between the two apexes is constant along an axial height of the rotor relative to the axis.

14 . The aircraft engine of claim 12 , wherein an outer face of the first female curved wall and an outer face of the second male curved wall are flush at the two apexes.

15 . The aircraft engine of claim 10 , comprising bearings disposed between end walls of the rotor and both of the movable wall and the static wall of the housing.

16 . The aircraft engine of claim 15 , wherein the bearings are balls rollingly received within grooves defined by the end walls.

17 . The aircraft engine of claim 10 , wherein the movable wall defines an annular groove, a sealing member received within the annular groove, the sealing member abutting the peripheral wall of the housing.

18 . The aircraft engine of claim 10 , wherein the housing includes a cover located opposite the static wall, the movable wall movable towards and away from the cover.

19 . The aircraft engine of claim 18 , wherein the actuator is located between the cover and the movable wall.

20 . A pump for an aircraft engine, comprising:

a housing defining an inlet and an outlet, the housing having walls enclosing a rotor cavity communicating with the inlet and the outlet, the walls including a static wall, a peripheral wall extending around an axis, and a movable wall in sealing contact with the peripheral wall;

an input shaft extending through the housing and parallel to the axis;

a rotor drivingly engaged by the input shaft and movably contained within the rotor cavity of the housing for orbital revolutions around the axis, the rotor having two end rotor walls and a peripheral rotor wall extending between the two rotor end walls, the rotor having two apexes sealingly contacting the peripheral wall of the housing during the orbital revolutions, the rotor having two sections movable relative to one another to vary a distance between the two rotor end walls;

an actuator operatively connected to the movable wall for moving the movable wall relative to the static wall to vary a volume of the rotor with movement of the movable wall; and

as biasing member for biasing the two sections of the rotor away from one another.