US20170306948A1 - Multiple Pressure Variable Displacement Pump with Mechanical Control - Google Patents
Multiple Pressure Variable Displacement Pump with Mechanical Control Download PDFInfo
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- US20170306948A1 US20170306948A1 US15/523,563 US201415523563A US2017306948A1 US 20170306948 A1 US20170306948 A1 US 20170306948A1 US 201415523563 A US201415523563 A US 201415523563A US 2017306948 A1 US2017306948 A1 US 2017306948A1
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- Prior art keywords
- pump
- control ring
- spring
- pump control
- chamber
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
- F04C14/18—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber
- F04C14/22—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
- F04C14/18—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber
- F04C14/22—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members
- F04C14/223—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members using a movable cam
- F04C14/226—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by varying the volume of the working chamber by changing the eccentricity between cooperating members using a movable cam by pivoting the cam around an eccentric axis
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2/00—Rotary-piston machines or pumps
- F04C2/30—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members
- F04C2/34—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members
- F04C2/344—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member
- F04C2/3441—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation
- F04C2/3442—Rotary-piston machines or pumps having the characteristics covered by two or more groups F04C2/02, F04C2/08, F04C2/22, F04C2/24 or having the characteristics covered by one of these groups together with some other type of movement between co-operating members having the movement defined in groups F04C2/08 or F04C2/22 and relative reciprocation between the co-operating members with vanes reciprocating with respect to the inner member the inner and outer member being in contact along one line or continuous surface substantially parallel to the axis of rotation the surfaces of the inner and outer member, forming the working space, being surfaces of revolution
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2210/00—Fluid
- F04C2210/14—Lubricant
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2270/00—Control; Monitoring or safety arrangements
- F04C2270/18—Pressure
- F04C2270/185—Controlled or regulated
Definitions
- variable displacement vane pumps relate to the field of variable displacement vane pumps, and more particularly, to a variable displacement vane pump having a biasing assembly that can provide multiple equilibrium pressures within a control chamber.
- Variable displacement vane pumps are well-known and can include a displacement adjusting structure in the form of a pump control ring that can be moved to alter the rotor eccentricity of the pump and hence alter the volumetric capacity of the pump. If the pump is supplying a system with a substantially constant orifice size, such as an automobile engine lubrication system, changing the output volume of the pump is equivalent to changing the pressure produced by the pump.
- Having the ability to alter the volumetric capacity of the pump to maintain an equilibrium pressure is important in environments in which the pump will be operated over a range of operating speeds, such as automobile lubrication pumps.
- a feedback supply of the working fluid e.g., lubricating oil
- the pressure in the control chamber acting to move the control ring, typically against a biasing force from a return spring, to alter the capacity of the pump.
- the equilibrium pressure is selected to be a pressure which is acceptable for expected operating range of the engine and is thus somewhat of a compromise, as, for example, the engine may be able to operate acceptably at lower operating speeds with a lower working fluid pressure than is required at a higher operating engine speeds.
- the engine designers will select an equilibrium pressure for the pump which meets the worst case (higher operating speeds) conditions.
- the pump will be operating at a higher capacity than necessary for those speeds, wasting energy pumping the surplus, unnecessary working fluid.
- variable displacement vane pumps having a housing, a biasing assembly, and a control chamber.
- the housing has a pump chamber.
- the pump chamber has a fluid inlet, a fluid outlet, a pump control ring, and a vane pump rotor.
- the pump control ring is disposed within the housing for altering the displacement of the pump by rotating between a first position that corresponds to a maximum volumetric capacity of the pump, a second position that corresponds to an intermediary volumetric capacity of the pump, and a third position that corresponds to a minimum volumetric capacity of the pump.
- the vane pump rotor is rotatably mounted within the pump control ring and has a plurality of slidably mounted vanes engaging an inside surface of the pump control ring.
- the vane pump rotor also has an axis of rotation eccentric from a center of the pump control ring.
- the vane pump rotor rotates to pressurize fluid as the fluid moves from the fluid inlet to the fluid outlet.
- the biasing assembly urges the pump control ring toward the first position.
- the biasing assembly applies a first biasing force to the pump control ring when the pump control ring is located between the first position and the second position and applies a second biasing force to the pump control ring when the pump control ring is located between the second position and the third position.
- the control chamber is formed between the housing and the pump control ring. The fluid pressure within the control chamber urges the pump control ring toward the third position.
- a second aspect of the disclosed embodiments is a variable displacement vane pump having a housing, a biasing assembly, a control chamber, a feedback path, and a spring chamber.
- the housing has a pump chamber.
- the pump chamber has a fluid inlet, a fluid outlet, a pump control ring, and a vane pump rotor.
- the pump control ring is disposed within the housing for altering the displacement of the pump by rotating between a first position that corresponds to a maximum volumetric capacity of the pump, a second position that corresponds to an intermediary volumetric capacity of the pump, and a third position that corresponds to a minimum volumetric capacity of the pump.
- the vane pump rotor is rotatably mounted within the pump control ring and has a plurality of slidably mounted vanes engaging an inside surface of the pump control ring.
- the vane pump rotor also has an axis of rotation eccentric from a center of the pump control ring.
- the vane pump rotor rotates to pressurize fluid as the fluid moves from the fluid inlet to the fluid outlet.
- the biasing assembly applies a first biasing force to the pump control ring when the pump control ring is located between the first position and the second position and applies a second biasing force to the pump control ring when the pump control ring is located between the second position and the third position.
- the control chamber is formed between the housing and the pump control ring.
- the fluid pressure within the control chamber urges the pump control ring toward the third position.
- the feedback path is in communication with the fluid outlet supplying a pressurized fluid to the control chamber.
- the spring chamber is formed between the housing and the pump control ring. The spring chamber has a maximum volume when the pump control ring is in the first position and a minimum volume when the pump control ring is in the third position.
- the biasing assembly is disposed within the spring chamber.
- FIG. 1 is a perspective view showing a variable displacement vane pump and an automotive oil sump reservoir
- FIG. 2 is an exploded perspective view showing the variable displacement vane pump and the automotive oil sump reservoir of FIG. 1 ;
- FIG. 3 is an illustration showing a control ring of the variable displacement vane pump in a first position that corresponds to a maximum volumetric capacity of the variable displacement vane pump;
- FIG. 4 is an illustration showing the control ring of the variable displacement vane pump in a second position that corresponds to an intermediary volumetric capacity of the variable displacement vane pump and a first stage equilibrium pressure;
- FIG. 5 is an illustration showing the control ring of the variable displacement vane pump in a third position that corresponds to a minimum volumetric capacity of the variable displacement vane pump and a second stage equilibrium pressure;
- FIG. 6 is a cross-sectional plain view of a biasing assembly of the variable displacement vane pump
- FIG. 7 is a diagram showing the variable displacement vane pump incorporated into a lubricating system of an automobile engine.
- FIG. 8 is a graph showing operation of the variable displacement vane pump with the biasing assembly.
- the present invention provides a pump that may be utilized to pump a fluid, such as automotive engine lubricant.
- the pump 10 may be a variable displacement vane pump. In automobile engine applications, the pump 10 may be connected to an oil sump reservoir 12 .
- a housing 14 of the pump 10 may include a back side 16 , a midsection 18 , a cover 20 , and a plate 22 .
- the midsection 18 forms the peripheral walls of the housing 14 , in which pumping and control chambers are formed, as will be explained herein.
- the cover 20 is connected to and sealed to the midsection 18 .
- the back side 16 of the housing defines fluid flow paths for the pump 10 to allow fluid to enter and exit the pump 10 .
- the plate 22 is mounted between the back side 16 and the midsection 18 of the housing 14 and includes apertures that define locations where fluid can pass between the back side 16 of the housing 14 and the chambers defined within the midsection 18 of the housing.
- a pump control ring 28 is pivotally connected to the housing 14 by a pivot pin 30 and, optionally, a needle bearing 32 .
- the pivot pin 30 extends through an aperture 31 that is formed near an outer periphery of a generally circular portion 60 (shown in FIGS. 3-5 ) of the pump control ring 28 .
- the needle bearing 32 is mounted between the pivot pin 30 and the pump control ring 28 so as to provide easy pivoting of the pump control ring 28 relative to the pivot pin 30 .
- a regulating member 62 (shown in FIGS. 3-5 ) extends outward from the circular portion 60 of the pump control ring 28 .
- the vane pump rotor 34 and the pump control ring 28 are substantially circular in shape.
- the center of the pump control ring 28 is located eccentrically with respect to the center of a vane pump rotor 34 is mounted within the pump control ring 28 .
- the vane pump rotor 34 has a plurality of vanes 36 that are mounted for sliding within slots that are formed in the vane pump rotor 34 .
- the vane pump rotor 34 includes a ring 35 (shown in FIGS. 3-5 ).
- the vanes 36 pass through openings formed in the ring 35 and are engaged by the ring 35 such that rotation of the ring 35 causes rotation of the vanes 36 .
- a single ring 35 is shown, some implementations includes two or more rings to help keep the vanes 36 in contact with the pump control ring 28 , especially at low speeds.
- the vanes 36 engage an inside surface (not shown) of the pump control ring 28 , and the vanes 36 slide within the slots in response to movement of the pump control ring 28 with respect to the vane pump rotor 34 .
- the vane pump rotor 34 has an axis of rotation that is eccentric from the center of the pump control ring 28 , as will be described further herein.
- a drive shaft 38 is driven by any suitable means, such as an automotive engine or other mechanism that can supply working fluid to operation the pump 10 .
- the drive shaft 38 engages the vane pump rotor 34 and rotates the vane pump rotor 34 as the drive shaft 38 is driven.
- the pump control ring 28 , the vane pump rotor 34 , and the vanes 36 cooperate to define working chambers 50 that are located between successive pairs of vanes 36 .
- Pumping from a fluid inlet 42 of the pump 10 to the fluid outlet 44 of the pump 10 occurs because the volume of each working chamber 50 changes as it passes from the fluid inlet 42 to the fluid outlet 44 , thereby increasing the pressure of the fluid.
- the fluid inlet 42 is the low pressure side of the pump 10
- the fluid outlet 44 is the high pressure side of the pump 10 .
- Pivoting of the pump control ring 28 is operable to vary the amount of volumetric change of each working chamber 50 during rotation, which in turn changes the volumetric displacement of the pump 10 .
- the pump control ring 28 pivots between a first position (shown in FIG. 3 ), a second position (shown in FIG. 4 ), and a third position (shown in FIG. 5 ).
- the first position corresponds to a maximum volumetric capacity of the pump 10 .
- the pump control ring 28 In the first position, the pump control ring 28 has reached its end limit of travel in a clockwise direction with respect to the pivot pin 30 by engagement of the pump control ring 28 with the housing 14 .
- the second position corresponds to an intermediary volumetric capacity of the pump 10 .
- the third position corresponds to a minimum volumetric capacity of the pump 10 .
- the pump control ring 28 has reached its end limit of travel in a counter-clockwise direction with respect to the pivot pin 30 .
- the volumetric capacity of the pump 10 varies as a function of the position of the pump control ring 28 , which under working conditions, often will be disposed somewhere between the first position and the third position.
- a spring chamber 40 and a control chamber 41 are defined within the housing 14 to regulate the position of the pump control ring 28 .
- a first seal 46 and a second seal 48 are mounted within respective recesses in the pump control ring 28 and engage an inner surface of the housing 14 to define the control chamber 41 .
- the control chamber 41 is formed within a space that is disposed outward of the pump control ring 28 , between the pump control ring 28 and an interior surface of the housing 14 .
- a second side 66 of the regulating member 62 faces the control chamber 41 .
- the volume of the control chamber 41 changes based on the position of the pump control ring 28 , given that the regulating member 62 moves with the pump control ring 28 .
- the control chamber 41 is at a minimum volume when the pump control ring 28 is in the first position.
- the volume of the control chamber 41 increases as the pump control ring 28 moves toward the third position and reaches a maximum volume when the pump control ring 28 is in the third position.
- the spring chamber 40 is formed within a space that is disposed outward of the pump control ring 28 , between the pump control ring 28 and an interior surface of the housing 14 .
- a first side 64 of a regulating member 62 faces the spring chamber 40 .
- the volume of the spring chamber 40 is at a maximum volume when the pump control ring 28 is in the first position.
- the volume of the spring chamber 40 decreases as the pump control ring 28 moves toward the third position and reaches a minimum volume when the pump control ring 28 is in the third position.
- a feedback path 82 supplies pressurized fluid to the control chamber 41 from a fluid outlet 44 of the pump 10 . This can be done directly, by routing the feedback path 82 directly to the control chamber 41 from the fluid outlet 44 , or indirectly, by routing the feedback path 82 to another portion of the pump 10 that is in fluid communication with the fluid outlet 44 and is at equilibrium with the fluid outlet 44 . Because the feedback path 82 is in fluid communication with the fluid outlet 44 of the pump 10 , the feedback path 82 receives pressurized fluid at the outlet pressure of the pump 10 . In some implementations, a restrictor (not shown) is formed along the feedback path 82 to control the amount of pressure provided via the feedback path 82 . In the illustrated example, the feedback path 82 is formed in housing 14 and is fluid communication with the control chamber 41 and the fluid outlet 44 .
- a biasing assembly 90 may be formed within the spring chamber 40 to control the position of the pump control ring 28 and the volume of the control chamber 41 .
- the biasing assembly 90 urges the pump control ring 28 toward the first position by applying a first biasing force to the pump control ring 28 when the pump control ring 28 is located between the first position and the second position.
- the pressure will eventually be able to overcome the first biasing force and move the pump control ring 28 toward the second position.
- the pressure within the control chamber 41 will remain substantially constant, resulting in a first equilibrium pressure.
- a second biasing force is activated and applied to urge the pump control ring 28 toward the second position. If the pressure continues to increase within the control chamber 41 , the pressure will eventually be sufficient to overcome the second biasing force and the pump control ring 28 will pivot toward the third position. As the pump control ring 28 pivots toward the third position, the pressure within the control chamber 41 will remain substantially constant, resulting in a second equilibrium pressure.
- two biasing forces are described, it will be obvious to one skilled in the art that the number of biasing forces acting on the pump control ring 28 could be varied to alter the number of equilibrium pressures that the pump 10 can maintain.
- the biasing assembly 90 has a first compression spring 51 , a second compression spring 52 , and a control pin 53 .
- the first compression spring 51 and the second compression spring 52 are substantially coaxially aligned with the first compression spring 51 positioned closer to the regulating member 62 .
- the first compression spring 51 applies a first spring load to the pump control ring 28 and the second compression spring 52 applies a second spring load to the pump control ring 28 .
- the second spring load is greater than the first spring load.
- the control pin 53 has a substantially T-shaped configuration with a first leg 54 extending through the radial center of the first compression spring 51 and a second leg 55 located between the first compression spring 51 and the second compression spring 52 .
- the spring chamber 40 may an annular shoulder 43 that the second leg 55 of the control pin 53 may abut to prevent the first leg 54 of the control pin 53 from engaging the regulating member 62 of the pump control ring 28 when the first compression spring 51 is not compressed.
- the first side 64 of the regulating member 62 engages a first end 56 of the first compression spring 51 and compresses the first compression spring 51 toward the second leg 55 of the control pin 53 .
- the second leg 55 of the control pin 53 will compress the second compression spring 52 toward the housing 14 .
- first compression spring 51 and the second compression spring 52 act independently in the illustrated example, it is anticipated that the first compression spring 51 and the second compression spring 52 could combine to provide the second biasing force.
- first compression spring 51 may have substantially the diameter as the width of the spring chamber 40 .
- the biasing assembly is not limited to being housed within the spring chamber 40 or utilizing compression springs. Other biasing assemblies could be utilized. For example, there could be two tension springs or two compression springs could be used in a location other than the spring chamber 40 .
- the first compression spring 51 and the second compression spring 52 have the same spring rate. In other implementations, the first compressions spring 51 and the second compression spring 52 have different spring rates. For example, the first compression spring 51 can have a first spring rate and the second compression spring 52 can have a second spring rate that is greater than the first spring rate 51 .
- FIG. 7 is a diagram showing the pump 10 incorporated in a lubricating system of an automobile engine 100 .
- the pump 10 receives fluid, such as oil, from the oil sump reservoir 12 at an inlet pressure P 1 via the fluid inlet 42 of the pump 10 .
- the pump 10 increases the pressure of the fluid to an outlet pressure P 2 , and the fluid exits the pump 10 at the fluid outlet 44 .
- the fluid travels from the fluid outlet 44 of the pump 10 to the automobile engine 100 via a supply circuit 102 and is subsequently returned to the oil sump reservoir 12 via a return circuit 104 .
- a portion of the fluid at the outlet pressure P 2 is diverted from the fluid outlet 44 of the pump 10 to the control chamber 41 via the feedback path 82 .
- the pump control ring 28 is rotated toward the third position, thereby decreasing the volumetric output of the pump 10 .
- the use of the biasing assembly 90 allows the pump 10 to provide multiple equilibrium pressures in the control chamber 41 , as shown in FIG. 8 .
- the pump control ring 28 is in the first position as the pressure in the control chamber 41 is not sufficient to overcome the first biasing force of the first compression spring 51 to compress the first compression spring 51 , which is shown as segment 701 .
- the pump 10 will have the maximum per-rotation volumetric capacity.
- the pump control ring 28 will move toward the second position, which is shown as segment 702 .
- the movement of the pump control ring 28 toward the second position linearly decreases the per-rotation volumetric capacity of the pump 10 and allows the pressure within the control chamber 41 to remain substantially constant at the first equilibrium pressure.
- the pump control ring 28 will move toward the third position, which is shown as segment 704 .
- the movement of the pump control ring 28 toward the third position linearly decreases the per-rotation volumetric capacity of the pump 10 and allows the pressure within the control chamber 41 to remain substantially constant at the second equilibrium pressure. Once the pump control ring 28 reaches the third position, the pump 10 will have the minimum volumetric capacity.
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Abstract
Description
- This disclosure relates to the field of variable displacement vane pumps, and more particularly, to a variable displacement vane pump having a biasing assembly that can provide multiple equilibrium pressures within a control chamber.
- Variable displacement vane pumps are well-known and can include a displacement adjusting structure in the form of a pump control ring that can be moved to alter the rotor eccentricity of the pump and hence alter the volumetric capacity of the pump. If the pump is supplying a system with a substantially constant orifice size, such as an automobile engine lubrication system, changing the output volume of the pump is equivalent to changing the pressure produced by the pump.
- Having the ability to alter the volumetric capacity of the pump to maintain an equilibrium pressure is important in environments in which the pump will be operated over a range of operating speeds, such as automobile lubrication pumps. In order to maintain an equilibrium pressure in such environments, it is known to utilize a feedback supply of the working fluid (e.g., lubricating oil) from the output of the pump to a control chamber adjacent the pump control ring, the pressure in the control chamber acting to move the control ring, typically against a biasing force from a return spring, to alter the capacity of the pump.
- When the pressure at the output of the pump increases, such as when the operating speed of the pump increases, the increased pressure is applied to the control ring to overcome the bias of the return spring and to move the control ring to reduce the capacity of the pump, thus reducing the output volume and hence the pressure at the output of the pump. Conversely, as the pressure at the output of the pump drops, such as when the operating speed of the pump decreases, the decreased pressure applied to the control chamber adjacent the control ring allows the bias of the return spring to move the control ring to increase the capacity of the pump, raising the output volume and hence pressure of the pump. In this manner, an equilibrium pressure is obtained at the output of the pump. The equilibrium pressure is determined by the area of the control ring against which the working fluid and the control chamber acts, the pressure of the working fluid supplied to the chamber, and the bias force generated by the return spring.
- Conventionally, the equilibrium pressure is selected to be a pressure which is acceptable for expected operating range of the engine and is thus somewhat of a compromise, as, for example, the engine may be able to operate acceptably at lower operating speeds with a lower working fluid pressure than is required at a higher operating engine speeds. To prevent undue wear or other damage to the engine, the engine designers will select an equilibrium pressure for the pump which meets the worst case (higher operating speeds) conditions. Thus, at lower speeds, the pump will be operating at a higher capacity than necessary for those speeds, wasting energy pumping the surplus, unnecessary working fluid.
- It is known to utilize more than one control chamber in order that more than one equilibrium pressure can be established within the pump. However, by establishing multiple control chambers, the pump must take on a greater size physically, thereby requiring the pump to have a larger overall size. A larger sized pump can limit the applications by which the pump can be utilized within an automobile engine compartment. In addition, the multiple control chambers require additional machining and parts, such as seals, thereby increasing the cost of such designs as compared to single chamber designs.
- Variable displacement vane pumps are described herein. One aspect of the disclosed embodiments is a variable displacement pump having a housing, a biasing assembly, and a control chamber. The housing has a pump chamber. The pump chamber has a fluid inlet, a fluid outlet, a pump control ring, and a vane pump rotor. The pump control ring is disposed within the housing for altering the displacement of the pump by rotating between a first position that corresponds to a maximum volumetric capacity of the pump, a second position that corresponds to an intermediary volumetric capacity of the pump, and a third position that corresponds to a minimum volumetric capacity of the pump. The vane pump rotor is rotatably mounted within the pump control ring and has a plurality of slidably mounted vanes engaging an inside surface of the pump control ring. The vane pump rotor also has an axis of rotation eccentric from a center of the pump control ring. The vane pump rotor rotates to pressurize fluid as the fluid moves from the fluid inlet to the fluid outlet. The biasing assembly urges the pump control ring toward the first position. The biasing assembly applies a first biasing force to the pump control ring when the pump control ring is located between the first position and the second position and applies a second biasing force to the pump control ring when the pump control ring is located between the second position and the third position. The control chamber is formed between the housing and the pump control ring. The fluid pressure within the control chamber urges the pump control ring toward the third position.
- A second aspect of the disclosed embodiments is a variable displacement vane pump having a housing, a biasing assembly, a control chamber, a feedback path, and a spring chamber. The housing has a pump chamber. The pump chamber has a fluid inlet, a fluid outlet, a pump control ring, and a vane pump rotor. The pump control ring is disposed within the housing for altering the displacement of the pump by rotating between a first position that corresponds to a maximum volumetric capacity of the pump, a second position that corresponds to an intermediary volumetric capacity of the pump, and a third position that corresponds to a minimum volumetric capacity of the pump. The vane pump rotor is rotatably mounted within the pump control ring and has a plurality of slidably mounted vanes engaging an inside surface of the pump control ring. The vane pump rotor also has an axis of rotation eccentric from a center of the pump control ring. The vane pump rotor rotates to pressurize fluid as the fluid moves from the fluid inlet to the fluid outlet. The biasing assembly applies a first biasing force to the pump control ring when the pump control ring is located between the first position and the second position and applies a second biasing force to the pump control ring when the pump control ring is located between the second position and the third position. The control chamber is formed between the housing and the pump control ring. The fluid pressure within the control chamber urges the pump control ring toward the third position. The feedback path is in communication with the fluid outlet supplying a pressurized fluid to the control chamber. The spring chamber is formed between the housing and the pump control ring. The spring chamber has a maximum volume when the pump control ring is in the first position and a minimum volume when the pump control ring is in the third position. The biasing assembly is disposed within the spring chamber.
- The various features, advantages, and other uses of the present disclosure will become more apparent by referring to the following drawings, in which:
-
FIG. 1 is a perspective view showing a variable displacement vane pump and an automotive oil sump reservoir; -
FIG. 2 is an exploded perspective view showing the variable displacement vane pump and the automotive oil sump reservoir ofFIG. 1 ; -
FIG. 3 is an illustration showing a control ring of the variable displacement vane pump in a first position that corresponds to a maximum volumetric capacity of the variable displacement vane pump; -
FIG. 4 is an illustration showing the control ring of the variable displacement vane pump in a second position that corresponds to an intermediary volumetric capacity of the variable displacement vane pump and a first stage equilibrium pressure; -
FIG. 5 is an illustration showing the control ring of the variable displacement vane pump in a third position that corresponds to a minimum volumetric capacity of the variable displacement vane pump and a second stage equilibrium pressure; -
FIG. 6 is a cross-sectional plain view of a biasing assembly of the variable displacement vane pump; -
FIG. 7 is a diagram showing the variable displacement vane pump incorporated into a lubricating system of an automobile engine; and -
FIG. 8 is a graph showing operation of the variable displacement vane pump with the biasing assembly. - The present invention provides a pump that may be utilized to pump a fluid, such as automotive engine lubricant. As illustrated in
FIGS. 1-2 , thepump 10 may be a variable displacement vane pump. In automobile engine applications, thepump 10 may be connected to anoil sump reservoir 12. Ahousing 14 of thepump 10 may include aback side 16, amidsection 18, acover 20, and aplate 22. Themidsection 18 forms the peripheral walls of thehousing 14, in which pumping and control chambers are formed, as will be explained herein. Thecover 20 is connected to and sealed to themidsection 18. Theback side 16 of the housing defines fluid flow paths for thepump 10 to allow fluid to enter and exit thepump 10. Theplate 22 is mounted between theback side 16 and themidsection 18 of thehousing 14 and includes apertures that define locations where fluid can pass between theback side 16 of thehousing 14 and the chambers defined within themidsection 18 of the housing. - A
pump control ring 28 is pivotally connected to thehousing 14 by apivot pin 30 and, optionally, a needle bearing 32. In particular, thepivot pin 30 extends through anaperture 31 that is formed near an outer periphery of a generally circular portion 60 (shown inFIGS. 3-5 ) of thepump control ring 28. If present, theneedle bearing 32 is mounted between thepivot pin 30 and thepump control ring 28 so as to provide easy pivoting of thepump control ring 28 relative to thepivot pin 30. A regulating member 62 (shown inFIGS. 3-5 ) extends outward from thecircular portion 60 of thepump control ring 28. Thevane pump rotor 34 and thepump control ring 28 are substantially circular in shape. The center of thepump control ring 28 is located eccentrically with respect to the center of avane pump rotor 34 is mounted within thepump control ring 28. - The
vane pump rotor 34 has a plurality ofvanes 36 that are mounted for sliding within slots that are formed in thevane pump rotor 34. Thevane pump rotor 34 includes a ring 35 (shown inFIGS. 3-5 ). Thevanes 36 pass through openings formed in thering 35 and are engaged by thering 35 such that rotation of thering 35 causes rotation of thevanes 36. Although asingle ring 35 is shown, some implementations includes two or more rings to help keep thevanes 36 in contact with thepump control ring 28, especially at low speeds. Thevanes 36 engage an inside surface (not shown) of thepump control ring 28, and thevanes 36 slide within the slots in response to movement of thepump control ring 28 with respect to thevane pump rotor 34. Thevane pump rotor 34 has an axis of rotation that is eccentric from the center of thepump control ring 28, as will be described further herein. Adrive shaft 38 is driven by any suitable means, such as an automotive engine or other mechanism that can supply working fluid to operation thepump 10. Thedrive shaft 38 engages thevane pump rotor 34 and rotates thevane pump rotor 34 as thedrive shaft 38 is driven. - As shown in
FIGS. 3-5 , thepump control ring 28, thevane pump rotor 34, and thevanes 36 cooperate to define workingchambers 50 that are located between successive pairs ofvanes 36. Pumping from afluid inlet 42 of thepump 10 to thefluid outlet 44 of thepump 10 occurs because the volume of each workingchamber 50 changes as it passes from thefluid inlet 42 to thefluid outlet 44, thereby increasing the pressure of the fluid. Thus, thefluid inlet 42 is the low pressure side of thepump 10, and thefluid outlet 44 is the high pressure side of thepump 10. - Pivoting of the
pump control ring 28 is operable to vary the amount of volumetric change of each workingchamber 50 during rotation, which in turn changes the volumetric displacement of thepump 10. In particular, thepump control ring 28 pivots between a first position (shown inFIG. 3 ), a second position (shown inFIG. 4 ), and a third position (shown inFIG. 5 ). The first position corresponds to a maximum volumetric capacity of thepump 10. In the first position, thepump control ring 28 has reached its end limit of travel in a clockwise direction with respect to thepivot pin 30 by engagement of thepump control ring 28 with thehousing 14. The second position corresponds to an intermediary volumetric capacity of thepump 10. The third position corresponds to a minimum volumetric capacity of thepump 10. In the third position, thepump control ring 28 has reached its end limit of travel in a counter-clockwise direction with respect to thepivot pin 30. The volumetric capacity of thepump 10 varies as a function of the position of thepump control ring 28, which under working conditions, often will be disposed somewhere between the first position and the third position. - A
spring chamber 40 and acontrol chamber 41 are defined within thehousing 14 to regulate the position of thepump control ring 28. Afirst seal 46 and asecond seal 48 are mounted within respective recesses in thepump control ring 28 and engage an inner surface of thehousing 14 to define thecontrol chamber 41. - The
control chamber 41 is formed within a space that is disposed outward of thepump control ring 28, between thepump control ring 28 and an interior surface of thehousing 14. Asecond side 66 of the regulatingmember 62 faces thecontrol chamber 41. The volume of thecontrol chamber 41 changes based on the position of thepump control ring 28, given that the regulatingmember 62 moves with thepump control ring 28. Thecontrol chamber 41 is at a minimum volume when thepump control ring 28 is in the first position. The volume of thecontrol chamber 41 increases as thepump control ring 28 moves toward the third position and reaches a maximum volume when thepump control ring 28 is in the third position. - The
spring chamber 40 is formed within a space that is disposed outward of thepump control ring 28, between thepump control ring 28 and an interior surface of thehousing 14. Afirst side 64 of a regulatingmember 62 faces thespring chamber 40. The volume of thespring chamber 40 is at a maximum volume when thepump control ring 28 is in the first position. The volume of thespring chamber 40 decreases as thepump control ring 28 moves toward the third position and reaches a minimum volume when thepump control ring 28 is in the third position. - A
feedback path 82 supplies pressurized fluid to thecontrol chamber 41 from afluid outlet 44 of thepump 10. This can be done directly, by routing thefeedback path 82 directly to thecontrol chamber 41 from thefluid outlet 44, or indirectly, by routing thefeedback path 82 to another portion of thepump 10 that is in fluid communication with thefluid outlet 44 and is at equilibrium with thefluid outlet 44. Because thefeedback path 82 is in fluid communication with thefluid outlet 44 of thepump 10, thefeedback path 82 receives pressurized fluid at the outlet pressure of thepump 10. In some implementations, a restrictor (not shown) is formed along thefeedback path 82 to control the amount of pressure provided via thefeedback path 82. In the illustrated example, thefeedback path 82 is formed inhousing 14 and is fluid communication with thecontrol chamber 41 and thefluid outlet 44. - A biasing
assembly 90 may be formed within thespring chamber 40 to control the position of thepump control ring 28 and the volume of thecontrol chamber 41. The biasingassembly 90 urges thepump control ring 28 toward the first position by applying a first biasing force to thepump control ring 28 when thepump control ring 28 is located between the first position and the second position. As the pressure increases within thecontrol chamber 41, the pressure will eventually be able to overcome the first biasing force and move thepump control ring 28 toward the second position. As thepump control ring 28 pivots toward the second position, the pressure within thecontrol chamber 41 will remain substantially constant, resulting in a first equilibrium pressure. Once thepump control ring 28 reaches the second position, a second biasing force is activated and applied to urge thepump control ring 28 toward the second position. If the pressure continues to increase within thecontrol chamber 41, the pressure will eventually be sufficient to overcome the second biasing force and thepump control ring 28 will pivot toward the third position. As thepump control ring 28 pivots toward the third position, the pressure within thecontrol chamber 41 will remain substantially constant, resulting in a second equilibrium pressure. Although two biasing forces are described, it will be obvious to one skilled in the art that the number of biasing forces acting on thepump control ring 28 could be varied to alter the number of equilibrium pressures that thepump 10 can maintain. - In the illustrated example, the biasing
assembly 90 has afirst compression spring 51, asecond compression spring 52, and acontrol pin 53. As shown inFIG. 6 , thefirst compression spring 51 and thesecond compression spring 52 are substantially coaxially aligned with thefirst compression spring 51 positioned closer to the regulatingmember 62. When engaged, thefirst compression spring 51 applies a first spring load to thepump control ring 28 and thesecond compression spring 52 applies a second spring load to thepump control ring 28. In some implementations, the second spring load is greater than the first spring load. Thecontrol pin 53 has a substantially T-shaped configuration with afirst leg 54 extending through the radial center of thefirst compression spring 51 and asecond leg 55 located between thefirst compression spring 51 and thesecond compression spring 52. Thespring chamber 40 may anannular shoulder 43 that thesecond leg 55 of thecontrol pin 53 may abut to prevent thefirst leg 54 of thecontrol pin 53 from engaging the regulatingmember 62 of thepump control ring 28 when thefirst compression spring 51 is not compressed. As the pressure increases within thecontrol chamber 41, thefirst side 64 of the regulatingmember 62 engages afirst end 56 of thefirst compression spring 51 and compresses thefirst compression spring 51 toward thesecond leg 55 of thecontrol pin 53. Once thefirst compression spring 51 has compressed to a distance that allows thefirst side 64 of the regulatingmember 62 to engage thefirst leg 54 of thecontrol pin 53, thesecond leg 55 of thecontrol pin 53 will compress thesecond compression spring 52 toward thehousing 14. - Although the
first compression spring 51 and thesecond compression spring 52 act independently in the illustrated example, it is anticipated that thefirst compression spring 51 and thesecond compression spring 52 could combine to provide the second biasing force. In this embodiment, thefirst compression spring 51 may have substantially the diameter as the width of thespring chamber 40. Once thefirst side 64 of the regulatingmember 62 is able to engage thefirst leg 54 of thecontrol pin 53, thefirst compression spring 51 continues compressing and thesecond compression spring 52 begins compressing due to force of the pressure in thecontrol chamber 41. - The biasing assembly is not limited to being housed within the
spring chamber 40 or utilizing compression springs. Other biasing assemblies could be utilized. For example, there could be two tension springs or two compression springs could be used in a location other than thespring chamber 40. In some implementations, thefirst compression spring 51 and thesecond compression spring 52 have the same spring rate. In other implementations, thefirst compressions spring 51 and thesecond compression spring 52 have different spring rates. For example, thefirst compression spring 51 can have a first spring rate and thesecond compression spring 52 can have a second spring rate that is greater than thefirst spring rate 51. -
FIG. 7 is a diagram showing thepump 10 incorporated in a lubricating system of anautomobile engine 100. Thepump 10 receives fluid, such as oil, from theoil sump reservoir 12 at an inlet pressure P1 via thefluid inlet 42 of thepump 10. Thepump 10 increases the pressure of the fluid to an outlet pressure P2, and the fluid exits thepump 10 at thefluid outlet 44. The fluid travels from thefluid outlet 44 of thepump 10 to theautomobile engine 100 via asupply circuit 102 and is subsequently returned to theoil sump reservoir 12 via areturn circuit 104. A portion of the fluid at the outlet pressure P2 is diverted from thefluid outlet 44 of thepump 10 to thecontrol chamber 41 via thefeedback path 82. As the pressure within thecontrol chamber 41 increases, thepump control ring 28 is rotated toward the third position, thereby decreasing the volumetric output of thepump 10. - The use of the biasing
assembly 90 allows thepump 10 to provide multiple equilibrium pressures in thecontrol chamber 41, as shown inFIG. 8 . Initially, thepump control ring 28 is in the first position as the pressure in thecontrol chamber 41 is not sufficient to overcome the first biasing force of thefirst compression spring 51 to compress thefirst compression spring 51, which is shown assegment 701. Duringsegment 701, thepump 10 will have the maximum per-rotation volumetric capacity. Once the pressure increases within thecontrol chamber 41 to a point where it is able to overcome the first biasing force of thefirst compression spring 51 and the regulatingmember 62 is able to compress thefirst compression spring 51, thepump control ring 28 will move toward the second position, which is shown assegment 702. The movement of thepump control ring 28 toward the second position linearly decreases the per-rotation volumetric capacity of thepump 10 and allows the pressure within thecontrol chamber 41 to remain substantially constant at the first equilibrium pressure. - As the pressure in the
control chamber 41 continues to rise, there will be a point where the regulatingmember 62 will engage thecontrol pin 53, preventing thefirst compression spring 51 from compressing further. As shown insegment 703, the per-rotation volumetric capacity of thepump 10 will remain constant because the pressure within thecontrol chamber 41 is unable to overcome the second biasing force of thesecond compression spring 52 to compress thesecond compression spring 52. As a result, thepump control ring 28 remains in the second position. Once the pressure increases within thecontrol chamber 41 to a point where it is able to overcome the second biasing force of thesecond compression spring 52 and thesecond leg 55 of thecontrol pin 53 is able to compress thesecond compression spring 52 toward thehousing 14, thepump control ring 28 will move toward the third position, which is shown assegment 704. The movement of thepump control ring 28 toward the third position linearly decreases the per-rotation volumetric capacity of thepump 10 and allows the pressure within thecontrol chamber 41 to remain substantially constant at the second equilibrium pressure. Once thepump control ring 28 reaches the third position, thepump 10 will have the minimum volumetric capacity. - While the description has been made in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiments, but to the contrary, it is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as is performed under the law.
Claims (20)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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PCT/US2014/063309 WO2016068971A1 (en) | 2014-10-31 | 2014-10-31 | Multiple pressure variable displacement pump with mechanical control |
Publications (1)
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US20170306948A1 true US20170306948A1 (en) | 2017-10-26 |
Family
ID=51946027
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US15/523,563 Abandoned US20170306948A1 (en) | 2014-10-31 | 2014-10-31 | Multiple Pressure Variable Displacement Pump with Mechanical Control |
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US (1) | US20170306948A1 (en) |
WO (1) | WO2016068971A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20200032791A1 (en) * | 2018-07-24 | 2020-01-30 | GM Global Technology Operations LLC | Spring structure with sliding element |
DE102021119936A1 (en) | 2021-07-30 | 2023-02-02 | Schwäbische Hüttenwerke Automotive GmbH | Rotary pump with variable structure spring with offset line of action |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20230023310A1 (en) * | 2021-07-23 | 2023-01-26 | Hamilton Sundstrand Corporation | Variable displacement pump systems with direct actuation |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2658456A (en) * | 1948-07-29 | 1953-11-10 | Gunnar A Wahlmark | Fluid displacement device |
US2768585A (en) * | 1952-12-18 | 1956-10-30 | Schwitzer Corp | Pump control mechanism |
WO2013049929A1 (en) * | 2011-10-07 | 2013-04-11 | Magna Powertrain, Inc. | Pre-compression dual spring pump control |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE457010B (en) * | 1983-09-17 | 1988-11-21 | Glyco Antriebstechnik Gmbh | ADJUSTABLE LUBRICANT PUMP |
JP4986726B2 (en) * | 2007-06-14 | 2012-07-25 | 日立オートモティブシステムズ株式会社 | Variable displacement pump |
JP4890604B2 (en) * | 2009-11-25 | 2012-03-07 | 日立オートモティブシステムズ株式会社 | Variable displacement pump |
JP5762202B2 (en) * | 2011-08-02 | 2015-08-12 | 日立オートモティブシステムズ株式会社 | Variable displacement vane pump |
-
2014
- 2014-10-31 WO PCT/US2014/063309 patent/WO2016068971A1/en active Application Filing
- 2014-10-31 US US15/523,563 patent/US20170306948A1/en not_active Abandoned
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2658456A (en) * | 1948-07-29 | 1953-11-10 | Gunnar A Wahlmark | Fluid displacement device |
US2768585A (en) * | 1952-12-18 | 1956-10-30 | Schwitzer Corp | Pump control mechanism |
WO2013049929A1 (en) * | 2011-10-07 | 2013-04-11 | Magna Powertrain, Inc. | Pre-compression dual spring pump control |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20200032791A1 (en) * | 2018-07-24 | 2020-01-30 | GM Global Technology Operations LLC | Spring structure with sliding element |
DE102021119936A1 (en) | 2021-07-30 | 2023-02-02 | Schwäbische Hüttenwerke Automotive GmbH | Rotary pump with variable structure spring with offset line of action |
Also Published As
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WO2016068971A1 (en) | 2016-05-06 |
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