Linear actuator pumping system

Patent metadata

Field	Value
Publication number	US-11396868-B2
Application number	US-202016812934-A
Country	US
Kind code	B2
Filing date	Mar 9, 2020
Priority date	Mar 9, 2020
Publication date	Jul 26, 2022
Grant date	Jul 26, 2022

Abstract

A pumping system utilizes a linear actuator to move a shaft attached to two pistons within cylinders to pump a working fluid. A housing is designed with coolant passageways and one-way valves such that movement of the shaft also pumps coolant past cooling fins and over a motor. The shaft is formed of several sections joined by couplers which slide within a bore of the housing. The couplers have a non-round shape and the bore has a complimentary non-round cross section such that rotation of the shaft is prevented.

First claim

What is claimed is:

1. A pumping system comprising:
a first housing having cooling fins, defining a first passageway proximate the cooling fins, defining a second passageway fluidly connected to a sump, and defining a first bore, the first and second passageways fluidly connected to the first bore;
a shaft supported to slide within the first bore in response to activation of a motor;
a first sliding seal between the first housing and the shaft axially fixed to the first housing;
a second sliding seal between the first housing and the shaft axially fixed to the shaft, thereby defining a first chamber within the first bore, the first chamber having a first volume that varies based on an axial position of the shaft;
a first one-way valve configured to prevent flow from the first passageway to the first chamber such that axial movement of the shaft in a first direction increases the first volume and draws a coolant from the sump, through the second passageway, and into the first chamber;
a second one-way valve configured to prevent flow from the first chamber to the second passageway such that axial movement of the shaft in a second direction decreases the first volume and forces the coolant through the first passageway, past the cooling fins, past the motor to cool the motor, and back to the sump;
a first cylinder fixed to the first housing;
a first piston slidably supported within the first cylinder and fixed to the shaft;
a third valve configured to permit flow of the fluid other than the coolant into the first cylinder in response to movement of the shaft in the first direction; and
a fourth valve configured to permit flow of the fluid from the first cylinder in response to movement of the shaft in the second direction.

2. The pumping system of claim 1 further comprising:
a second housing defining a third passageway, defining a fourth passageway fluidly connected to the sump, and defining a second bore, the third and fourth passageways fluidly connected to the second bore, the shaft supported to slide within the second bore in response to activation of the motor;
a third seal between the second housing and the shaft axially fixed to the second housing;
a fourth seal between the second housing and the shaft axially fixed to the shaft, thereby defining a second chamber within the second bore, the second chamber having a second volume that varies based on the axial position of the shaft;
a fifth one-way valve configured to prevent flow from the third passageway to the second chamber such that axial movement of the shaft in the second direction increases the second volume and draws the coolant from the sump, through the fourth passageway, and into the second chamber; and
a sixth one-way valve configured to prevent flow from the second chamber to the fourth passageway such that axial movement of the shaft in the first direction decreases the second volume and forces the coolant through the third passageway, past the motor to cool the motor, and back to the sump.

3. The pumping system of claim 2 further comprising:
a second cylinder fixed to the second housing;
a second piston slidably supported within the second cylinder and fixed to the shaft;
a seventh valve configured to permit flow of the fluid into the second cylinder in response to movement of the shaft in the second direction; and
an eighth valve configured to permit flow of the fluid from the second cylinder in response to movement of the shaft in the first direction.

4. The pumping system of claim 2 wherein the first housing and the second housing are identical.

5. A pumping system comprising:
a central housing having a sump;
left and right side housings fixed to the central housing, each side housing having cooling fins and defining a bore and first and second passageways, each first passageway fluidly connecting the sump to the respective bore, each second passageway being proximate the respective cooling fins and fluidly connecting the respective bore to a top end of the central housing;
a shaft extending through the central housing and through the bores of each side housing;
a motor located in the central housing and configured to move the shaft axially;
two end sliding seals between shaft and each of the side housings, the end seals axially fixed to the side housings;
two middle sliding seals between the shaft and each of the side housings, the middle seals axially fixed to the shaft, thereby defining first chambers within the respective bore, the first chambers having respective first volumes that vary based on an axial position of the shaft; and
a set of one-way valves configured such that
axial movement of the shaft towards the right side housing draws coolant from the sump, through the first passageway of the left side housing, into the bore of the left side housing and propels coolant from the bore of right side housing, through the second passageway of the right side housing, and across the motor back to the sump, and
axial movement of the shaft towards the left side housing draws coolant from the sump, through the first passageway of the right side housing, into the bore of the right side housing and propels coolant from the bore of left side housing, through the second passageway of the left side housing, and across the motor back to the sump.

6. The pumping system of claim 5 further comprising:
left and right cylinders fixed to the left and right side housings, respectively;
left and right pistons slidably supported within the left and right cylinders, respectively, fixed to left and right ends of the shaft, respectively; and
a second set of valves configured such that
axial movement of the shaft towards the right side housing draws a working fluid into the left cylinder and propels the working fluid from the right cylinder, and
axial movement of the shaft towards the left side housing draws the working fluid into the right cylinder and propels the working fluid from the left cylinder.

7. The pumping system of claim 5 wherein a section of the shaft between the middle seals is threaded, and the motor drives the shaft via a screw drive mechanism.

8. The pumping system of claim 7 wherein the bores have a non-round cross section, and wherein the middle seals have a shape that is complementary to the shape of the bore cross-section thereby preventing rotation of the shaft with respect to the housings.

9. A pumping system comprising:
a first housing having cooling fins, defining a first passageway proximate the cooling fins, defining a second passageway fluidly connected to a sump, and defining a first bore, the first and second passageways fluidly connected to the first bore;
a shaft supported to slide within the first bore in response to activation of a motor;
a first sliding seal between the first housing and the shaft axially fixed to the first housing;
a second sliding seal between the first housing and the shaft axially fixed to the shaft, thereby defining a first chamber within the first bore, the first chamber having a first volume that varies based on an axial position of the shaft;
a first one-way valve configured to prevent flow from the first passageway to the first chamber such that axial movement of the shaft in a first direction increases the first volume and draws a coolant from the sump, through the second passageway, and into the first chamber;
a second one-way valve configured to prevent flow from the first chamber to the second passageway such that axial movement of the shaft in a second direction decreases the first volume and forces the coolant through the first passageway, past the cooling fins, past the motor to cool the motor, and back to the sump; and
the shaft has a first section extending fro

Assignees

• Schaeffler Technologies Ag

Inventors

• Vazquez Andre
• Hooker Craig
• White Michael
• Conlin Michael
• OVENDORF Eric

Classifications

• H02K35/04

  with moving coil systems and stationary magnets · CPC title

• F04B47/02

  the driving mechanisms being situated at ground level (F04B47/12 takes precedence) · CPC title

• F04B53/02

  Packing the free space between cylinders and pistons · CPC title

• F04B35/04

  the means being electric · CPC title

• F04B9/02

  the means being mechanical · CPC title