US20050074349A1 - Pump with reciprocating high pressure seal and valve for vehicle braking systems - Google Patents
Pump with reciprocating high pressure seal and valve for vehicle braking systems Download PDFInfo
- Publication number
- US20050074349A1 US20050074349A1 US10/678,676 US67867603A US2005074349A1 US 20050074349 A1 US20050074349 A1 US 20050074349A1 US 67867603 A US67867603 A US 67867603A US 2005074349 A1 US2005074349 A1 US 2005074349A1
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- United States
- Prior art keywords
- passageway
- piston
- inlet
- seal
- flange
- Prior art date
- 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.)
- Abandoned
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B60—VEHICLES IN GENERAL
- B60T—VEHICLE BRAKE CONTROL SYSTEMS OR PARTS THEREOF; BRAKE CONTROL SYSTEMS OR PARTS THEREOF, IN GENERAL; ARRANGEMENT OF BRAKING ELEMENTS ON VEHICLES IN GENERAL; PORTABLE DEVICES FOR PREVENTING UNWANTED MOVEMENT OF VEHICLES; VEHICLE MODIFICATIONS TO FACILITATE COOLING OF BRAKES
- B60T8/00—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force
- B60T8/32—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration
- B60T8/34—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition
- B60T8/40—Arrangements for adjusting wheel-braking force to meet varying vehicular or ground-surface conditions, e.g. limiting or varying distribution of braking force responsive to a speed condition, e.g. acceleration or deceleration having a fluid pressure regulator responsive to a speed condition comprising an additional fluid circuit including fluid pressurising means for modifying the pressure of the braking fluid, e.g. including wheel driven pumps for detecting a speed condition, or pumps which are controlled by means independent of the braking system
- B60T8/4031—Pump units characterised by their construction or mounting
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
- F04B1/0404—Details or component parts
- F04B1/0408—Pistons
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
- F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
- F04B1/0404—Details or component parts
- F04B1/0452—Distribution members, e.g. valves
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
- F04B53/00—Component parts, details or accessories not provided for in, or of interest apart from, groups F04B1/00 - F04B23/00 or F04B39/00 - F04B47/00
- F04B53/10—Valves; Arrangement of valves
- F04B53/12—Valves; Arrangement of valves arranged in or on pistons
- F04B53/125—Reciprocating valves
- F04B53/127—Disc valves
- F04B53/128—Annular disc valves
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/16—Sealings between relatively-moving surfaces
- F16J15/164—Sealings between relatively-moving surfaces the sealing action depending on movements; pressure difference, temperature or presence of leaking fluid
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16J—PISTONS; CYLINDERS; SEALINGS
- F16J15/00—Sealings
- F16J15/56—Other sealings for reciprocating rods
Definitions
- This invention relates in general to brake systems for vehicles and in particular to a pump assembly with a combination reciprocating high-pressure seal and fluid inlet check valve for use within brake systems.
- a supply of hydraulic fluid for the vehicle brakes is modulated by a hydraulic control unit.
- Various hydraulic pumps may be employed to selectively supply hydraulic fluid to the vehicle brakes.
- Several hydraulic pump designs are known.
- U.S. Pat. No. 4,556,261 to Farr discloses a prior art pump and skid sensing assembly for a vehicle hydraulic anti-skid braking system, as shown in FIGS. 1 and 2 .
- the assembly comprises a housing 1 incorporating a hydraulic pump 2 , and a solenoid-operated valve assembly 3 . Only the operation of the pump 2 will be described herein, as the operation of the rest of the anti-skid braking system is not relevant to the present invention.
- the pump 2 includes a plunger 10 , which reciprocates within a stepped bore 11 in the housing 1 .
- the plunger 10 is engageable with a drive mechanism comprising a ring 12 rotatable on a shaft 4 .
- the plunger 10 carries an ‘O’ ring seal 18 and a lip seal 19 .
- the seals 18 and 19 are disposed on opposite sides of a passage 20 leading to the valve 3 .
- the seals 18 and 19 , the plunger 10 , and the bore 11 define a chamber 22 .
- a reservoir 35 supplies the chamber 22 with fluid.
- the seal 19 which is illustrated in detail in FIG. 2 , comprises an annular ring of elastomeric material, which is received in an annular groove 25 in the plunger 10 .
- the groove 25 is parallel sided and is of an axial length greater than the thickness of the seal 19 .
- Opposite faces 26 and 27 of the seal 19 are respectively planar and of reduced area, with the face 27 of reduced area being provided with at least one diametrical slot 28 which communicates with one or more passages 29 in the inner peripheral edge of the seal 19 .
- the planar face 26 is adapted to seal against the adjacent, inner, face of the groove 25 to prevent flow from the secondary chamber 22 into the reservoir 35 .
- the seal 19 is rather complex in that it contains at least one slot 28 and at least one passage 29 formed therethrough to control fluid flow through the seal 19 .
- the seal 19 moves relative to the plunger 10 so that the face 26 is spaced apart from the adjacent face of the groove 25 . This allows fluid from the reservoir 35 to be drawn into the increasing volume of the chamber 22 past the seal 19 with flow taking place through the slot 28 and the at least one passage 29 in the seal 19 .
- the face 26 of the seal 19 seals against the adjacent face of the groove 25 so that fluid cannot flow between the plunger 10 and the seal 19 or through the slot 28 and the at least one passage 29 within the seal 19 .
- the seal 19 in this condition thus provides a seal between the plunger 10 and the wall of the bore 11 , allowing the plunger 10 to pump fluid from the secondary chamber 22 into the primary chamber 23 .
- the present invention is a pump assembly with a combination reciprocating high-pressure seal and fluid inlet check valve for use within brake systems.
- the pump assembly comprises a piston for reciprocal movement within a bore in a housing.
- the pump assembly includes a housing having a bore formed therethrough and a piston disposed within the bore for reciprocal movement therein.
- An annular seal is disposed around the piston for reciprocal movement thereon.
- the piston has at least one passageway formed therein. The passageway, the piston, and the annular seal cooperating to form a check valve assembly.
- the check valve assembly divides the bore into an inlet chamber and a pumping chamber.
- the annular seal is moveable to a first position relative to the piston in which said check valve assembly is in a flow-through position to fill the pumping chamber with fluid from the inlet chamber during a fluid inlet stroke.
- the annular seal is moveable to a second position relative to the piston in which the check valve assembly is closed to pressurize the fluid within the pumping chamber during a pumping stroke.
- the piston includes a retaining flange, an inlet flange, and an intermediate portion disposed therebetween. Both the retaining flange and the inlet flange extend substantially perpendicular from the piston.
- the intermediate portion of the piston has at least one passageway formed therethrough.
- the retaining flange also has at least one passageway formed therethrough. The at least one passageway of the intermediate portion and the at least one passageway of the retaining flange are communicably connected.
- the inlet flange also has at least one passageway formed therethrough.
- a high-pressure seal is disposed around the intermediate portion of the piston.
- the seal is not as thick as the intermediate portion is long, and, therefore, the seal can reciprocate between the retaining flange and inlet flange.
- the seal and the inlet flange cooperate to form a first check valve assembly, as will be described below.
- the piston, housing, the first check valve assembly, and a second check valve assembly define a pumping chamber.
- the piston, housing, and the first check valve assembly define an inlet chamber.
- a fluid inlet supplies fluid to the inlet chamber.
- the piston withdraws from the bore and the volume of the pumping chamber increases.
- the seal is moved into a first position relative to the inlet flange, in which the seal is not seated against the inlet flange.
- the first check valve assembly is opened, and fluid from the inlet chamber is allowed to flow into the pumping chamber.
- the piston moves toward the second check valve assembly, and the seal is moved into a second position relative to the inlet flange, in which the seal is seated against the inlet flange.
- the inlet flange and seal cooperate to prevent fluid from exiting the pumping chamber, such that the first check valve assembly is closed.
- the fluid pressure builds within the pumping chamber until the pressure overcomes the force required to unseat the ball of the second check valve assembly.
- the second check valve assembly then opens, allowing the pressurized fluid to exit the pumping chamber through a fluid outlet to be delivered to the vehicle brake system.
- the at least one passageway in the retaining flange is communicably connected to at least one passageway in the seal.
- the seal and the inlet flange form a check valve assembly.
- the check valve assembly When the seal is in the first position, fluid is allowed to flow through the at least one passageway in the inlet flange, below the seal, through the passageway in the seal, through the at least one passageway in the retaining flange, and into the pumping chamber.
- the check valve assembly is in a flow-through position.
- the seal is in a second position, seated against the sealing surface of the inlet flange, the at least one passageway in the seal is prevented from communicating with the at least one passageway in the inlet flange.
- the check valve assembly is in a closed position.
- FIG. 1 is a cross sectional view of a known prior art hydraulic pump assembly.
- FIG. 2 is a cross sectional view of the seal of the known prior art hydraulic pump assembly illustrated in FIG. 1 .
- FIG. 3 is a prospective view of a first embodiment of a piston in accordance with the present invention.
- FIG. 4 is a cross sectional view of the piston shown in FIG. 3 , taken along line 4 - 4 , with the piston disposed within a first embodiment of a pump assembly, in accordance with the present invention.
- FIG. 5 is a cross sectional view of the pump assembly of FIG. 4 .
- FIG. 6 is an enlarged cross sectional view of a portion of a second embodiment of a pump assembly in accordance with the present invention.
- FIG. 3 a first embodiment of a piston, indicated generally at 50 , in accordance with this invention.
- the piston 50 comprises a shaft 51 , a retaining flange 52 , and an inlet flange 53 .
- the retaining flange 52 extends substantially perpendicular from the shaft 51 at a first end portion 54 of the shaft 51 .
- the inlet flange 53 extends substantially perpendicular from the shaft 51 below and spaced apart from the retaining flange 52 .
- the retaining flange 52 and the inlet flange 53 cooperate to define an intermediate portion 55 of the shaft 51 disposed between retaining flange 52 and the inlet flange 53 .
- the shaft 51 is generally elongated along a longitudinal axis A.
- the shaft 51 includes a second end portion 56 , opposite the first end portion 54 .
- the intermediate portion 55 described above is disposed between the first end portion 54 and the second end portion 56 .
- the second end portion 56 is engaged by a driving mechanism (not shown) for reciprocatingly driving the piston 50 .
- the intermediate portion 55 of the shaft 51 may have a generally circular cross section.
- the intermediate portion 55 extends outwardly from the axis A to a radius R 1 , as is shown in FIGS. 4 and 5 , and as will be described further below.
- the intermediate portion 55 has at least one passageway 57 formed therethrough.
- the at least one passageway 57 comprises a plurality of longitudinally extending grooves, with preferably semi-circular cross-section, that have been machined through the intermediate portion 55 of the shaft 51 around the periphery of the intermediate portion 55 .
- the at least one passageway 57 comprises a plurality of longitudinally extending notches molded in the intermediate portion 55 , with preferably rectangular or diamond-shaped cross-section.
- the at least one passageway 57 may be formed in the intermediate portion 55 in any manner, and may have any suitable cross-section.
- semi-circular encompasses any portion of a circle, which includes but is not limited to half of a circle.
- the at least one passageway 57 is formed through the intermediate portion 55 such that no part of the at least one passageway 57 extends further into the intermediate portion 55 than a radius R 2 from the axis A.
- the retaining flange 52 may have a generally circular cross section, and has a radius taken from the axis A that is larger than the radius R 1 of the intermediate portion 55 , the purpose of which will be described below.
- the retaining flange 52 has at least one passageway 58 formed therethrough.
- the at least one passageway 58 comprises a plurality of longitudinally extending grooves, preferably with semi-circular cross-section, that have been machined through the retaining flange 52 around the periphery of the retaining flange 52 .
- the at least one passageway 58 comprises a plurality of longitudinally extending notches molded in the retaining flange 52 , with preferably rectangular or diamond-shaped cross-section.
- the at least one passageway 58 may be formed in the retaining flange 52 in any manner, and may have any suitable cross-section. It will also be appreciated that the retaining flange 52 may be any one of a plurality of nubs or tangs extending outwardly from said piston 50 , the purpose of which will be described below.
- the at least one passageway 58 is formed through the retaining flange 52 such that the at least one passageway 58 does not extend into the retaining flange 52 any closer than a radius R 3 from the axis A as seen in FIG. 4 .
- the radius R 3 is smaller than the radius R 1 of the intermediate portion, the such that the at least one passageway 58 is aligned to radially overlap the at least one passageway 57 , and the at least one passageway 58 and the at least one passageway 57 are connected in fluid communication.
- the inlet flange 53 may have a circular cross section, and has at least one passageway 59 formed therethrough.
- the at least one passageway 59 comprises a plurality of longitudinally extending grooves, preferably with semi-circular cross-section, that have been machined through the inlet flange 53 around the periphery of the inlet flange 53 .
- the at least one passageway 59 comprises a plurality of longitudinally extending notches molded in the inlet flange 53 , with preferably rectangular or diamond-shaped cross-section.
- the at least one passageway 59 may be formed in the inlet flange 53 in any manner, and may have any suitable cross-section.
- the at least one passageway 59 is formed through the inlet flange 53 such that the at least one passageway 59 does not extend further into the inlet flange 53 any closer than a radius R 4 from the axis A, as seen in FIG. 4 .
- the radius R 4 is greater than the radius R 1 , the outer radius of the at least one passageway 57 , such that even though the at least one passageway 57 and the passageway 59 may be aligned to overlap radially, the at least one passageway 57 and the at least one passageway 59 are not directly communicably connected with one another.
- the piston 50 is suitable for use in a pump assembly, such as the first embodiment of a pump assembly, indicated generally at 60 , in FIGS. 4 and 5 .
- the pump assembly 60 comprises a housing 61 having a bore 62 formed therethrough.
- the piston 50 is mounted for reciprocal movement within the bore 62 of the housing 61 .
- the piston 50 is formed of a material that is sufficient to sustain operation of the pump assembly 60 under operating conditions within the pump assembly 60 as described herein, such as the relatively high operating pressures of a pump assembly within a vehicle brake system.
- the piston 50 is comprised of materials that are compatible with hydraulic brake fluid.
- An annular high-pressure seal 63 is disposed around the intermediate portion 55 of the piston 50 .
- the high-pressure seal 63 has a generally rectangular radial cross section as illustrated for each portion of the seal 63 shown on either side of the axis A in FIG. 4 .
- the seal may have any radial cross-section.
- the seal 63 is not as thick as the intermediate portion 55 is long, such that the seal 63 can reciprocate between the retaining flange 52 and the inlet flange 53 of the piston 50 , as will be described below.
- the seal 63 is preferably elastomeric.
- the seal 63 includes a base material, such as Polytetrafluoroethylene (PTFE) sold under the tradename Teflon® and manufactured by DuPont, and a filler material, such as carbon.
- PTFE Polytetrafluoroethylene
- the seal 63 includes carbon fiber, or other high tensile strength fibers suitable for use in composite materials.
- the seal 63 is formed of a material that is sufficient to sustain operation of the pump assembly 60 under operating conditions within the pump assembly 60 as described herein, such as the relatively high operating pressures of a pump assembly within a vehicle brake system.
- the seal 63 is formed of a material that is sufficient to sustain operation of the pump assembly 60 with an operating pressure range of about 0 to about 250 bars absolute pressure within the pump assembly 60 , as will be described in more detail below. However, it will be appreciated that operating pressure within the pump assembly 60 may vary, and may be a negative pressure under some operating conditions, as will be described below.
- the seal 63 is formed of a material that is sufficient to sustain operation of the pump assembly 60 in a temperature range of about ⁇ 40 degrees Celsius to about 120 degrees Celsius. Additionally, in a preferred embodiment, the seal 63 is comprised of materials that are compatible with hydraulic brake fluid.
- the seal 63 has a first surface 64 that slidingly engages the walls of the housing 61 that form the bore 62 to form a dynamic seal therebetween.
- the seal 63 also has a second surface 65 that slidingly engages the outer periphery of the intermediate portion 55 of the piston 50 , although such is not required.
- the seal 63 is able to move relative to the intermediate portion 55 between a first position, in which the seal 63 contacts the retaining flange 52 and a second position, in which the seal 63 contacts the inlet flange 53 as will be described below.
- the second surface 65 may seal against only the outer periphery of the intermediate portion 55 , and does not contact the inner periphery of the at least one passageway 57 , such that the seal 63 does not enter the at least one passageway 57 . Thus, no seal is formed between the seal 63 and the intermediate portion 55 .
- the seal 63 further includes a third surface 66 that engages a surface 68 of the retaining flange 52 when the seal 63 is in the first position thereof.
- the at least one passageway 58 is a plurality of similar passageways in the form of grooves that are symmetrically positioned around the retaining flange 52 , so that the seal 63 is evenly axially supported by the retaining flange 52 when seated in the first position.
- the seal 63 has a fourth surface 67 that may engage a sealing surface 69 of the inlet flange 53 when the seal 63 is in a second position relative to the inlet flange 53 , as will be described below.
- the fourth surface 67 engages the sealing surface 69 .
- the seal 63 prevents fluid flow through the at least one passageway 59 through the inlet flange 53 , because, as is best shown in FIG. 5 , the seal 63 seats against the sealing surface 69 blocking the passageway 59 .
- Fluid is not able to flow out of the at least one passageway 57 past the seal 63 , so fluid is not able to flow from the at least one passageway 57 , around the seal 63 , and into the at least one passageway 59 . Therefore, the seal 63 , in the second position, prevents the at least one passageway 57 and the at least one passageway 59 from fluid communication with one another.
- the seal 63 and the inlet flange 53 cooperate to form a first check valve assembly 70 , as will be described in more detail below.
- the at least one passageway 59 is a plurality of similar passageways that are symmetrically positioned around the inlet flange 53 , so that the seal 63 is evenly supported by the inlet flange 53 when seated in the second position.
- the pump assembly 60 will now be further described.
- the second end portion 56 of the piston 50 is mounted so that the piston 50 may reciprocate within the bore 62 of the housing 61 .
- the piston 50 slides against the walls of the bore 62 as the piston 50 reciprocates.
- a seal 71 may be provided or formed by the piston 50 and the walls of the bore 62 .
- the seal 71 , the seal 63 , and the piston 50 define an inlet chamber 72 within the bore 62 .
- a fluid inlet 73 is communicably connected to the inlet chamber 72 to supply fluid to the pump assembly 60 , as will be described below.
- the seal 71 may not be provided, and the inlet chamber 72 may extend such that the fluid of the inlet chamber 72 may be used to lubricate the piston 50 and the walls of the bore 62 to facilitate the reciprocal movement therebetween.
- an o-ring (not shown) may be disposed around the shaft 51 of the piston 50 near the second end portion 56 of the piston 50 instead of the seal 71 such that the inlet chamber 72 extends below the intersection of the walls of the bore 62 and the piston 50 .
- a second check valve assembly 74 is provided at the end of the bore 62 opposite the piston 50 .
- the second check valve assembly 74 includes a ball 75 and a seat 76 .
- the second check valve assembly 74 is formed of a material that is sufficient to sustain operation of the pump assembly 60 under operating conditions within the pump assembly 60 as described herein, such as the relatively high operating pressures of a pump assembly within a vehicle brake system.
- second check valve assembly 74 is comprised of materials that are compatible with hydraulic brake fluid.
- a pumping chamber 77 is defined within the bore 62 between the second check valve assembly 74 and the combination of the piston 50 and the seal 63 .
- the seal 63 is in the second position, thereby seated against the sealing surface 69 of the inlet flange 53 (the first check valve assembly 70 is shut).
- the piston 50 moves away from the second check valve assembly 74 .
- the seal 63 is disposed between the retaining flange 52 and the inlet flange 53 , and, as the piston 50 moves away from the second check valve assembly 74 , pressure in the pumping chamber 77 drops below the pressure in the inlet chamber 72 as the pumping chamber 77 expands.
- the differential pressure unseats the seal 63 from the inlet flange 53 , opening the first check valve assembly 70 and allowing fluid to flow from the inlet chamber 72 through the passageways 59 , 57 , and 58 , into the pumping chamber 77 .
- the seal 63 will generally have greater friction to the wall of the bore 62 than to the piston 50 , and will tend to remain stationary as the piston 50 moves.
- the retaining flange 52 will eventually intercept the seal 63 , and the seal 63 will be drug away from the second check valve assembly 74 by the retaining flange 52 of the piston 50 , so that the seal 63 is now in the first position thereof.
- the seal 63 will remain seated against the retaining flange 52 as long as the piston 50 continues to move in the same direction, e.g., away from the second check valve assembly 74 .
- the piston 50 moves back toward the second check valve assembly 74 .
- the seal 63 again tends to remain stationary due to friction with the wall of the bore.
- pressure starts to rise, even with the first check valve assembly 70 still open, due to head losses in the passageways.
- the seal 63 moves out of the second position thereof.
- the inlet flange 53 will eventually intercept the seal 63 , and the seal 63 will be drug toward the second check valve assembly 74 by the inlet flange 53 of the piston 50 .
- the seal 63 will remain in the second position thereof, i.e. seated against the inlet flange 53 , as long as the piston 50 continues to move in the same direction, e.g., toward the second check valve assembly 74 .
- the first check valve assembly 70 is in the closed position, as illustrated in FIG. 5 .
- the pumping chamber 77 is isolated from the inlet chamber 72 .
- the volume of the pumping chamber 77 decreases, and pressure is raised in the fluid within the pumping chamber 77 .
- the fluid pressure within the chamber 77 continues to build until the fluid pressure within the chamber 77 is greater than the resistance required to unseat the ball 75 from the seat 76 of the second check valve assembly 74 .
- the second check valve assembly 74 opens and pressurized fluid is discharged from the pump 60 via an outlet 78 .
- the pump assembly 60 may be a self-priming or pre-charging pump, and the pump assembly 60 may operate with negative pressure conditions within the inlet chamber 72 .
- the first end portion 54 of the piston 50 is relatively close to the second check valve assembly 74 .
- the first check valve assembly 70 and the second check valve assembly 74 are in relatively close proximity to one another, such that the pumping chamber 77 is relatively small, as compared to the pumping chambers of conventional pumps.
- the axial distance between the first check valve assembly 70 and the second check valve assembly 74 is minimized so that the pump assembly 60 has a relatively small unswept volume.
- the size and design of the seal 63 , the at least one passageway 58 of the retaining flange 52 , and the at least one passageway 59 of the inlet flange 53 must be coordinated so that the seal 63 and piston 50 cooperate such that the pump 60 operates as described above.
- the seal 63 , the at least one passageway 58 of the retaining flange 52 , and the at least one passageway 59 of the inlet flange 53 could be any size or shape capable of performing as described above.
- FIG. 6 there is illustrated a portion of a second embodiment of a pump assembly, indicated generally at 160 , in accordance with this invention.
- the pump assembly 160 is similar to the pump assembly 60 , and only those elements that differ will be described herein, and corresponding elements have been given the same reference numeral incremented by 100.
- the piston 150 includes a retaining flange 152 , an inlet flange 153 , and an intermediate portion 155 disposed therebetween. Unlike the intermediate portion 55 of the piston 50 , the intermediate portion 155 of the piston 150 does not have a passageway formed therethrough. Instead, the intermediate portion 155 is preferably circular in cross-section, and is slidingly engaged by a seal 163 . The seal 163 may reciprocate between the retaining flange 152 and the inlet flange 153 , in a manner similar to that described above for the seal 63 .
- the seal 163 differs from the seal 63 in that the seal 163 has at least one passageway 180 formed therethrough.
- the at least one passageway 180 has an outer radius R 1 from the axis A.
- the outer radius R 1 is smaller than the inner radius R 4 of the at least one passageway 159 in the inlet flange 153 .
- the outer radius R 1 is larger than the inner radius R 3 of the at least one passageway 158 in the retaining flange 152 .
- the seal 163 and the inlet flange 153 form a check valve assembly 170 .
- the at least one passageway 158 in the retaining flange 152 is communicably connected to the at least one passageway 180 in the seal 163 .
- the at least one passageway 180 is a plurality of passageways sized such that no matter how the seal 163 is rotated relative to the retaining flange 152 , the at least one passageway 180 is communicably connected to the at least one passageway 158 of the retaining flange 152 , when the seal 163 is seated against the surface 168 .
- the seal 163 When the seal 163 is in a first position relative to the inlet flange 153 , the seal 163 is unseated from the sealing surface 169 of the inlet flange 153 , and may be seated against the surface 168 of the retaining flange 152 , as described in the previous embodiment and as shown in FIG. 6 .
- the seal 163 When the seal 163 is in the first position, fluid is allowed to flow through the at least one passageway 159 , below the seal 163 , through the passageway 180 , through the at least one passageway 158 , and into the pumping chamber 177 .
- the check valve assembly 170 is in a flow-through position.
- the check valve assembly 170 is in a closed position, such that the pump 160 works in a manner similar to that described for the pump 60 .
- the pistons 50 , 150 , seals 63 , 163 and pump assemblies, 60 , 160 have been described for use in a vehicle braking system, including, but not limited to, vehicle braking systems having anti-lock braking systems, and/or integrated or stand alone traction control and vehicle stability control systems. However, it will be appreciated that the pistons 50 , 150 , the seals 63 , 163 and pump assemblies 60 , 160 may be used in any vehicle component or in any other device requiring a piston, seal, or pump assembly.
Abstract
Description
- This invention relates in general to brake systems for vehicles and in particular to a pump assembly with a combination reciprocating high-pressure seal and fluid inlet check valve for use within brake systems.
- In conventional vehicular brake systems having anti-lock brake, traction control and/or vehicle stability control, a supply of hydraulic fluid for the vehicle brakes is modulated by a hydraulic control unit. Various hydraulic pumps may be employed to selectively supply hydraulic fluid to the vehicle brakes. Several hydraulic pump designs are known.
- U.S. Pat. No. 4,556,261 to Farr, discloses a prior art pump and skid sensing assembly for a vehicle hydraulic anti-skid braking system, as shown in
FIGS. 1 and 2 . The assembly comprises a housing 1 incorporating a hydraulic pump 2, and a solenoid-operatedvalve assembly 3. Only the operation of the pump 2 will be described herein, as the operation of the rest of the anti-skid braking system is not relevant to the present invention. The pump 2 includes a plunger 10, which reciprocates within a stepped bore 11 in the housing 1. The plunger 10 is engageable with a drive mechanism comprising aring 12 rotatable on ashaft 4. The plunger 10 carries an ‘O’ ring seal 18 and alip seal 19. Theseals 18 and 19 are disposed on opposite sides of a passage 20 leading to thevalve 3. Theseals 18 and 19, the plunger 10, and the bore 11 define achamber 22. Areservoir 35 supplies thechamber 22 with fluid. - The
seal 19, which is illustrated in detail inFIG. 2 , comprises an annular ring of elastomeric material, which is received in anannular groove 25 in the plunger 10. Thegroove 25 is parallel sided and is of an axial length greater than the thickness of theseal 19.Opposite faces seal 19 are respectively planar and of reduced area, with theface 27 of reduced area being provided with at least onediametrical slot 28 which communicates with one ormore passages 29 in the inner peripheral edge of theseal 19. Theplanar face 26 is adapted to seal against the adjacent, inner, face of thegroove 25 to prevent flow from thesecondary chamber 22 into thereservoir 35. Theseal 19 is rather complex in that it contains at least oneslot 28 and at least onepassage 29 formed therethrough to control fluid flow through theseal 19. - As the plunger 10 is moved towards the
ring 12, theseal 19 moves relative to the plunger 10 so that theface 26 is spaced apart from the adjacent face of thegroove 25. This allows fluid from thereservoir 35 to be drawn into the increasing volume of thechamber 22 past theseal 19 with flow taking place through theslot 28 and the at least onepassage 29 in theseal 19. As the plunger 10 is moved in the opposite direction, theface 26 of theseal 19 seals against the adjacent face of thegroove 25 so that fluid cannot flow between the plunger 10 and theseal 19 or through theslot 28 and the at least onepassage 29 within theseal 19. Theseal 19 in this condition thus provides a seal between the plunger 10 and the wall of the bore 11, allowing the plunger 10 to pump fluid from thesecondary chamber 22 into theprimary chamber 23. - Although prior hydraulic pumps, such as the one described above, have been effective, it would be desirable to provide a low cost pump assembly having more easily manufactured and more durable components.
- The present invention is a pump assembly with a combination reciprocating high-pressure seal and fluid inlet check valve for use within brake systems. The pump assembly comprises a piston for reciprocal movement within a bore in a housing.
- The pump assembly includes a housing having a bore formed therethrough and a piston disposed within the bore for reciprocal movement therein. An annular seal is disposed around the piston for reciprocal movement thereon. The piston has at least one passageway formed therein. The passageway, the piston, and the annular seal cooperating to form a check valve assembly. The check valve assembly divides the bore into an inlet chamber and a pumping chamber. The annular seal is moveable to a first position relative to the piston in which said check valve assembly is in a flow-through position to fill the pumping chamber with fluid from the inlet chamber during a fluid inlet stroke. The annular seal is moveable to a second position relative to the piston in which the check valve assembly is closed to pressurize the fluid within the pumping chamber during a pumping stroke.
- In a preferred embodiment, the piston includes a retaining flange, an inlet flange, and an intermediate portion disposed therebetween. Both the retaining flange and the inlet flange extend substantially perpendicular from the piston. The intermediate portion of the piston has at least one passageway formed therethrough. The retaining flange also has at least one passageway formed therethrough. The at least one passageway of the intermediate portion and the at least one passageway of the retaining flange are communicably connected. The inlet flange also has at least one passageway formed therethrough.
- A high-pressure seal is disposed around the intermediate portion of the piston. The seal is not as thick as the intermediate portion is long, and, therefore, the seal can reciprocate between the retaining flange and inlet flange. The seal and the inlet flange cooperate to form a first check valve assembly, as will be described below.
- The piston, housing, the first check valve assembly, and a second check valve assembly define a pumping chamber. The piston, housing, and the first check valve assembly define an inlet chamber. A fluid inlet supplies fluid to the inlet chamber.
- On a fluid inlet stroke, the piston withdraws from the bore and the volume of the pumping chamber increases. As the piston withdraws, the seal is moved into a first position relative to the inlet flange, in which the seal is not seated against the inlet flange. With the seal in the first position, the first check valve assembly is opened, and fluid from the inlet chamber is allowed to flow into the pumping chamber.
- On a pumping stroke, the piston moves toward the second check valve assembly, and the seal is moved into a second position relative to the inlet flange, in which the seal is seated against the inlet flange. When the seal is in the second position, the inlet flange and seal cooperate to prevent fluid from exiting the pumping chamber, such that the first check valve assembly is closed. The fluid pressure builds within the pumping chamber until the pressure overcomes the force required to unseat the ball of the second check valve assembly. The second check valve assembly then opens, allowing the pressurized fluid to exit the pumping chamber through a fluid outlet to be delivered to the vehicle brake system.
- In an alternate embodiment of the invention, the at least one passageway in the retaining flange is communicably connected to at least one passageway in the seal. The seal and the inlet flange form a check valve assembly. When the seal is in the first position, fluid is allowed to flow through the at least one passageway in the inlet flange, below the seal, through the passageway in the seal, through the at least one passageway in the retaining flange, and into the pumping chamber. Thus, the check valve assembly is in a flow-through position. When the seal is in a second position, seated against the sealing surface of the inlet flange, the at least one passageway in the seal is prevented from communicating with the at least one passageway in the inlet flange. Thus, the check valve assembly is in a closed position.
- Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment, when read in light of the accompanying drawings.
-
FIG. 1 is a cross sectional view of a known prior art hydraulic pump assembly. -
FIG. 2 is a cross sectional view of the seal of the known prior art hydraulic pump assembly illustrated inFIG. 1 . -
FIG. 3 is a prospective view of a first embodiment of a piston in accordance with the present invention. -
FIG. 4 is a cross sectional view of the piston shown inFIG. 3 , taken along line 4-4, with the piston disposed within a first embodiment of a pump assembly, in accordance with the present invention. -
FIG. 5 is a cross sectional view of the pump assembly ofFIG. 4 . -
FIG. 6 is an enlarged cross sectional view of a portion of a second embodiment of a pump assembly in accordance with the present invention. - Referring again to the drawings, there is illustrated in
FIG. 3 , a first embodiment of a piston, indicated generally at 50, in accordance with this invention. Thepiston 50 comprises ashaft 51, a retainingflange 52, and aninlet flange 53. The retainingflange 52 extends substantially perpendicular from theshaft 51 at afirst end portion 54 of theshaft 51. Theinlet flange 53 extends substantially perpendicular from theshaft 51 below and spaced apart from the retainingflange 52. The retainingflange 52 and theinlet flange 53 cooperate to define anintermediate portion 55 of theshaft 51 disposed between retainingflange 52 and theinlet flange 53. - The
shaft 51 is generally elongated along a longitudinal axis A. Theshaft 51 includes asecond end portion 56, opposite thefirst end portion 54. Theintermediate portion 55, described above is disposed between thefirst end portion 54 and thesecond end portion 56. Thesecond end portion 56 is engaged by a driving mechanism (not shown) for reciprocatingly driving thepiston 50. Theintermediate portion 55 of theshaft 51 may have a generally circular cross section. Theintermediate portion 55 extends outwardly from the axis A to a radius R1, as is shown inFIGS. 4 and 5 , and as will be described further below. Theintermediate portion 55 has at least onepassageway 57 formed therethrough. In a preferred embodiment, the at least onepassageway 57 comprises a plurality of longitudinally extending grooves, with preferably semi-circular cross-section, that have been machined through theintermediate portion 55 of theshaft 51 around the periphery of theintermediate portion 55. In a more preferred embodiment, the at least onepassageway 57 comprises a plurality of longitudinally extending notches molded in theintermediate portion 55, with preferably rectangular or diamond-shaped cross-section. However, it will be appreciated that the at least onepassageway 57 may be formed in theintermediate portion 55 in any manner, and may have any suitable cross-section. As used throughout the application, semi-circular encompasses any portion of a circle, which includes but is not limited to half of a circle. The at least onepassageway 57 is formed through theintermediate portion 55 such that no part of the at least onepassageway 57 extends further into theintermediate portion 55 than a radius R2 from the axis A. - The retaining
flange 52 may have a generally circular cross section, and has a radius taken from the axis A that is larger than the radius R1 of theintermediate portion 55, the purpose of which will be described below. The retainingflange 52 has at least onepassageway 58 formed therethrough. In a preferred embodiment, the at least onepassageway 58 comprises a plurality of longitudinally extending grooves, preferably with semi-circular cross-section, that have been machined through the retainingflange 52 around the periphery of the retainingflange 52. In a more preferred embodiment, the at least onepassageway 58 comprises a plurality of longitudinally extending notches molded in the retainingflange 52, with preferably rectangular or diamond-shaped cross-section. However, it will be appreciated that the at least onepassageway 58 may be formed in the retainingflange 52 in any manner, and may have any suitable cross-section. It will also be appreciated that the retainingflange 52 may be any one of a plurality of nubs or tangs extending outwardly from saidpiston 50, the purpose of which will be described below. The at least onepassageway 58 is formed through the retainingflange 52 such that the at least onepassageway 58 does not extend into the retainingflange 52 any closer than a radius R3 from the axis A as seen inFIG. 4 . The radius R3 is smaller than the radius R1 of the intermediate portion, the such that the at least onepassageway 58 is aligned to radially overlap the at least onepassageway 57, and the at least onepassageway 58 and the at least onepassageway 57 are connected in fluid communication. - The
inlet flange 53 may have a circular cross section, and has at least onepassageway 59 formed therethrough. In a preferred embodiment, the at least onepassageway 59 comprises a plurality of longitudinally extending grooves, preferably with semi-circular cross-section, that have been machined through theinlet flange 53 around the periphery of theinlet flange 53. In a more preferred embodiment, the at least onepassageway 59 comprises a plurality of longitudinally extending notches molded in theinlet flange 53, with preferably rectangular or diamond-shaped cross-section. However, it will be appreciated that the at least onepassageway 59 may be formed in theinlet flange 53 in any manner, and may have any suitable cross-section. The at least onepassageway 59 is formed through theinlet flange 53 such that the at least onepassageway 59 does not extend further into theinlet flange 53 any closer than a radius R4 from the axis A, as seen inFIG. 4 . The radius R4 is greater than the radius R1, the outer radius of the at least onepassageway 57, such that even though the at least onepassageway 57 and thepassageway 59 may be aligned to overlap radially, the at least onepassageway 57 and the at least onepassageway 59 are not directly communicably connected with one another. - The
piston 50 is suitable for use in a pump assembly, such as the first embodiment of a pump assembly, indicated generally at 60, inFIGS. 4 and 5 . Thepump assembly 60 comprises ahousing 61 having abore 62 formed therethrough. Thepiston 50 is mounted for reciprocal movement within thebore 62 of thehousing 61. Preferably, thepiston 50 is formed of a material that is sufficient to sustain operation of thepump assembly 60 under operating conditions within thepump assembly 60 as described herein, such as the relatively high operating pressures of a pump assembly within a vehicle brake system. Additionally, in a preferred embodiment, thepiston 50 is comprised of materials that are compatible with hydraulic brake fluid. - An annular high-
pressure seal 63 is disposed around theintermediate portion 55 of thepiston 50. In a preferred embodiment, the high-pressure seal 63 has a generally rectangular radial cross section as illustrated for each portion of theseal 63 shown on either side of the axis A inFIG. 4 . However, it will be appreciated that the seal may have any radial cross-section. In a preferred embodiment, theseal 63 is not as thick as theintermediate portion 55 is long, such that theseal 63 can reciprocate between the retainingflange 52 and theinlet flange 53 of thepiston 50, as will be described below. Theseal 63 is preferably elastomeric. In a preferred embodiment, theseal 63 includes a base material, such as Polytetrafluoroethylene (PTFE) sold under the tradename Teflon® and manufactured by DuPont, and a filler material, such as carbon. In a more preferred embodiment, theseal 63 includes carbon fiber, or other high tensile strength fibers suitable for use in composite materials. Preferably, theseal 63 is formed of a material that is sufficient to sustain operation of thepump assembly 60 under operating conditions within thepump assembly 60 as described herein, such as the relatively high operating pressures of a pump assembly within a vehicle brake system. In a preferred embodiment, theseal 63 is formed of a material that is sufficient to sustain operation of thepump assembly 60 with an operating pressure range of about 0 to about 250 bars absolute pressure within thepump assembly 60, as will be described in more detail below. However, it will be appreciated that operating pressure within thepump assembly 60 may vary, and may be a negative pressure under some operating conditions, as will be described below. In a preferred embodiment, theseal 63 is formed of a material that is sufficient to sustain operation of thepump assembly 60 in a temperature range of about −40 degrees Celsius to about 120 degrees Celsius. Additionally, in a preferred embodiment, theseal 63 is comprised of materials that are compatible with hydraulic brake fluid. - The
seal 63 has afirst surface 64 that slidingly engages the walls of thehousing 61 that form thebore 62 to form a dynamic seal therebetween. Theseal 63 also has asecond surface 65 that slidingly engages the outer periphery of theintermediate portion 55 of thepiston 50, although such is not required. Theseal 63 is able to move relative to theintermediate portion 55 between a first position, in which theseal 63 contacts the retainingflange 52 and a second position, in which theseal 63 contacts theinlet flange 53 as will be described below. Thesecond surface 65 may seal against only the outer periphery of theintermediate portion 55, and does not contact the inner periphery of the at least onepassageway 57, such that theseal 63 does not enter the at least onepassageway 57. Thus, no seal is formed between theseal 63 and theintermediate portion 55. - The
seal 63 further includes athird surface 66 that engages asurface 68 of the retainingflange 52 when theseal 63 is in the first position thereof. As indicated above, in a preferred embodiment, the at least onepassageway 58 is a plurality of similar passageways in the form of grooves that are symmetrically positioned around the retainingflange 52, so that theseal 63 is evenly axially supported by the retainingflange 52 when seated in the first position. - The
seal 63 has afourth surface 67 that may engage a sealingsurface 69 of theinlet flange 53 when theseal 63 is in a second position relative to theinlet flange 53, as will be described below. When theseal 63 is in the second position, thefourth surface 67 engages the sealingsurface 69. Theseal 63 prevents fluid flow through the at least onepassageway 59 through theinlet flange 53, because, as is best shown inFIG. 5 , theseal 63 seats against the sealingsurface 69 blocking thepassageway 59. Fluid is not able to flow out of the at least onepassageway 57 past theseal 63, so fluid is not able to flow from the at least onepassageway 57, around theseal 63, and into the at least onepassageway 59. Therefore, theseal 63, in the second position, prevents the at least onepassageway 57 and the at least onepassageway 59 from fluid communication with one another. - Thus, the
seal 63 and theinlet flange 53 cooperate to form a firstcheck valve assembly 70, as will be described in more detail below. In a preferred embodiment, the at least onepassageway 59 is a plurality of similar passageways that are symmetrically positioned around theinlet flange 53, so that theseal 63 is evenly supported by theinlet flange 53 when seated in the second position. - The
pump assembly 60 will now be further described. Thesecond end portion 56 of thepiston 50 is mounted so that thepiston 50 may reciprocate within thebore 62 of thehousing 61. Thepiston 50 slides against the walls of thebore 62 as thepiston 50 reciprocates. Aseal 71 may be provided or formed by thepiston 50 and the walls of thebore 62. Theseal 71, theseal 63, and thepiston 50 define aninlet chamber 72 within thebore 62. Afluid inlet 73 is communicably connected to theinlet chamber 72 to supply fluid to thepump assembly 60, as will be described below. Alternatively, it will be appreciated that theseal 71 may not be provided, and theinlet chamber 72 may extend such that the fluid of theinlet chamber 72 may be used to lubricate thepiston 50 and the walls of thebore 62 to facilitate the reciprocal movement therebetween. In a more preferred embodiment, an o-ring (not shown) may be disposed around theshaft 51 of thepiston 50 near thesecond end portion 56 of thepiston 50 instead of theseal 71 such that theinlet chamber 72 extends below the intersection of the walls of thebore 62 and thepiston 50. - At the end of the
bore 62 opposite thepiston 50, a secondcheck valve assembly 74 is provided. The secondcheck valve assembly 74 includes aball 75 and aseat 76. Preferably, the secondcheck valve assembly 74 is formed of a material that is sufficient to sustain operation of thepump assembly 60 under operating conditions within thepump assembly 60 as described herein, such as the relatively high operating pressures of a pump assembly within a vehicle brake system. Additionally, in a preferred embodiment, secondcheck valve assembly 74 is comprised of materials that are compatible with hydraulic brake fluid. A pumpingchamber 77 is defined within thebore 62 between the secondcheck valve assembly 74 and the combination of thepiston 50 and theseal 63. As is evident from the structure of thepump 60 and as will be evident from the operation of thepump 60 described below, thepump 60 is highly efficient due to the relatively small unswept volume of thepiston 50. - The operation of the
pump assembly 60 will now be described. At the end of a pumping stroke, when thepiston 50 is closest to the secondcheck valve assembly 74, theseal 63 is in the second position, thereby seated against the sealingsurface 69 of the inlet flange 53 (the firstcheck valve assembly 70 is shut). During a fluid inlet stroke, thepiston 50 moves away from the secondcheck valve assembly 74. Theseal 63 is disposed between the retainingflange 52 and theinlet flange 53, and, as thepiston 50 moves away from the secondcheck valve assembly 74, pressure in thepumping chamber 77 drops below the pressure in theinlet chamber 72 as the pumpingchamber 77 expands. The differential pressure unseats theseal 63 from theinlet flange 53, opening the firstcheck valve assembly 70 and allowing fluid to flow from theinlet chamber 72 through thepassageways chamber 77. Theseal 63 will generally have greater friction to the wall of thebore 62 than to thepiston 50, and will tend to remain stationary as thepiston 50 moves. However, as thepiston 50 continues to move away from the secondcheck valve assembly 74, the retainingflange 52 will eventually intercept theseal 63, and theseal 63 will be drug away from the secondcheck valve assembly 74 by the retainingflange 52 of thepiston 50, so that theseal 63 is now in the first position thereof. Once theseal 63 has been intercepted by the retainingflange 52, theseal 63 will remain seated against the retainingflange 52 as long as thepiston 50 continues to move in the same direction, e.g., away from the secondcheck valve assembly 74. - During a pumping stroke, the
piston 50 moves back toward the secondcheck valve assembly 74. As thepiston 50 moves, theseal 63 again tends to remain stationary due to friction with the wall of the bore. Additionally, as the pumping chamber gets smaller as thepiston 50 moves toward the secondcheck valve assembly 74, pressure starts to rise, even with the firstcheck valve assembly 70 still open, due to head losses in the passageways. Thus, theseal 63 moves out of the second position thereof. As thepiston 50 continues to move toward the secondcheck valve assembly 74, theinlet flange 53 will eventually intercept theseal 63, and theseal 63 will be drug toward the secondcheck valve assembly 74 by theinlet flange 53 of thepiston 50. Once theseal 63 has been intercepted by theinlet flange 53, theseal 63 will remain in the second position thereof, i.e. seated against theinlet flange 53, as long as thepiston 50 continues to move in the same direction, e.g., toward the secondcheck valve assembly 74. When theseal 63 is in the second position thereof, the firstcheck valve assembly 70 is in the closed position, as illustrated inFIG. 5 . With theseal 63 seated against the sealingsurface 69 of theinlet flange 53, fluid cannot flow into the at least onepassageway 59 from the at least onepassageway 57. Therefore, the pumpingchamber 77 is isolated from theinlet chamber 72. Thus, as thepiston 50 moves further into thebore 62, the volume of the pumpingchamber 77 decreases, and pressure is raised in the fluid within the pumpingchamber 77. - As the
piston 50 continues to move toward the secondcheck valve assembly 74, the fluid pressure within thechamber 77 continues to build until the fluid pressure within thechamber 77 is greater than the resistance required to unseat theball 75 from theseat 76 of the secondcheck valve assembly 74. When theball 75 is unseated, the secondcheck valve assembly 74 opens and pressurized fluid is discharged from thepump 60 via anoutlet 78. - As the
piston 50 continues to move toward the secondcheck valve assembly 74, the volume of theinlet chamber 72 increases. The increase in volume of theinlet chamber 72 may create negative pressure or a vacuum pressure within theinlet chamber 72. This vacuum pressure within theinlet chamber 72 pulls fluid from thefluid inlet 73 into theinlet chamber 72. Thus, thepump assembly 60 may be a self-priming or pre-charging pump, and thepump assembly 60 may operate with negative pressure conditions within theinlet chamber 72. At the end of a pumping stroke, thefirst end portion 54 of thepiston 50 is relatively close to the secondcheck valve assembly 74. With thepiston 50 in this position, the firstcheck valve assembly 70 and the secondcheck valve assembly 74 are in relatively close proximity to one another, such that the pumpingchamber 77 is relatively small, as compared to the pumping chambers of conventional pumps. The axial distance between the firstcheck valve assembly 70 and the secondcheck valve assembly 74 is minimized so that thepump assembly 60 has a relatively small unswept volume. - It will be appreciated that the size and design of the
seal 63, the at least onepassageway 58 of the retainingflange 52, and the at least onepassageway 59 of theinlet flange 53, must be coordinated so that theseal 63 andpiston 50 cooperate such that thepump 60 operates as described above. Conversely, it will be appreciated that theseal 63, the at least onepassageway 58 of the retainingflange 52, and the at least onepassageway 59 of theinlet flange 53 could be any size or shape capable of performing as described above. - Referring now to
FIG. 6 , there is illustrated a portion of a second embodiment of a pump assembly, indicated generally at 160, in accordance with this invention. Thepump assembly 160 is similar to thepump assembly 60, and only those elements that differ will be described herein, and corresponding elements have been given the same reference numeral incremented by 100. - The piston 150 includes a retaining
flange 152, aninlet flange 153, and an intermediate portion 155 disposed therebetween. Unlike theintermediate portion 55 of thepiston 50, the intermediate portion 155 of the piston 150 does not have a passageway formed therethrough. Instead, the intermediate portion 155 is preferably circular in cross-section, and is slidingly engaged by aseal 163. Theseal 163 may reciprocate between the retainingflange 152 and theinlet flange 153, in a manner similar to that described above for theseal 63. - The
seal 163 differs from theseal 63 in that theseal 163 has at least onepassageway 180 formed therethrough. The at least onepassageway 180 has an outer radius R1 from the axis A. The outer radius R1 is smaller than the inner radius R4 of the at least onepassageway 159 in theinlet flange 153. The outer radius R1 is larger than the inner radius R3 of the at least onepassageway 158 in the retainingflange 152. - The
seal 163 and theinlet flange 153 form a check valve assembly 170. However, the structure of the check valve assembly 170 varies from structure of thecheck valve assembly 70. The at least onepassageway 158 in the retainingflange 152 is communicably connected to the at least onepassageway 180 in theseal 163. In a preferred embodiment, the at least onepassageway 180 is a plurality of passageways sized such that no matter how theseal 163 is rotated relative to the retainingflange 152, the at least onepassageway 180 is communicably connected to the at least onepassageway 158 of the retainingflange 152, when theseal 163 is seated against thesurface 168. - When the
seal 163 is in a first position relative to theinlet flange 153, theseal 163 is unseated from the sealingsurface 169 of theinlet flange 153, and may be seated against thesurface 168 of the retainingflange 152, as described in the previous embodiment and as shown inFIG. 6 . When theseal 163 is in the first position, fluid is allowed to flow through the at least onepassageway 159, below theseal 163, through thepassageway 180, through the at least onepassageway 158, and into thepumping chamber 177. Thus, the check valve assembly 170 is in a flow-through position. When theseal 163 is in a second position, seated against the sealingsurface 169 of theinlet flange 153, the at least onepassageway 180 in theseal 163 is prevented from communicating with the at least onepassageway 159. Thus, the check valve assembly 170 is in a closed position, such that thepump 160 works in a manner similar to that described for thepump 60. - The
pistons 50, 150, seals 63, 163 and pump assemblies, 60, 160 have been described for use in a vehicle braking system, including, but not limited to, vehicle braking systems having anti-lock braking systems, and/or integrated or stand alone traction control and vehicle stability control systems. However, it will be appreciated that thepistons 50, 150, theseals pump assemblies
Claims (22)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/678,676 US20050074349A1 (en) | 2003-10-03 | 2003-10-03 | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
PCT/US2004/032607 WO2005032897A1 (en) | 2003-10-03 | 2004-10-01 | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
EP04794085A EP1667880A1 (en) | 2003-10-03 | 2004-10-01 | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
US11/479,594 US20060275165A1 (en) | 2003-10-03 | 2006-06-30 | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/678,676 US20050074349A1 (en) | 2003-10-03 | 2003-10-03 | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
Related Child Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US11/479,594 Continuation-In-Part US20060275165A1 (en) | 2003-10-03 | 2006-06-30 | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
Publications (1)
Publication Number | Publication Date |
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US20050074349A1 true US20050074349A1 (en) | 2005-04-07 |
Family
ID=34393985
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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US10/678,676 Abandoned US20050074349A1 (en) | 2003-10-03 | 2003-10-03 | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
Country Status (1)
Country | Link |
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US (1) | US20050074349A1 (en) |
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US20060106740A1 (en) * | 2004-11-12 | 2006-05-18 | General Electric Company | Creation and correction of future time interval power generation curves for power generation costing and pricing |
US7104613B2 (en) | 2004-07-28 | 2006-09-12 | Kelsey-Hayes Company | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
US20060275165A1 (en) * | 2003-10-03 | 2006-12-07 | Wilke Westley J | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
WO2010037555A1 (en) * | 2008-10-02 | 2010-04-08 | Hydac Electronic Gmbh | Spool valve |
US20110227014A1 (en) * | 2010-03-16 | 2011-09-22 | Lautzenhiser Lloyd L | Hydraulic pumpling cylinder and method of pumping hydraulic fluid |
WO2011147494A1 (en) * | 2010-05-27 | 2011-12-01 | Wabco Gmbh | Device having a molded seal |
WO2012097854A1 (en) * | 2011-01-20 | 2012-07-26 | Schaeffler Technologies AG & Co. KG | Piston assembly |
US8708669B1 (en) * | 2007-02-12 | 2014-04-29 | Brunswick Corporation | Fuel pumping system |
WO2014198267A1 (en) * | 2013-06-10 | 2014-12-18 | Schaeffler Technologies Gmbh & Co. Kg | Piston/cylinder arrangement for a hydraulic disengagement device, in particular a master cylinder for a hydraulic shift actuating device |
US10393112B2 (en) * | 2014-02-17 | 2019-08-27 | Robert Bosch Gmbh | Piston fuel pump for an internal combustion engine |
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US4114059A (en) * | 1976-09-03 | 1978-09-12 | Westinghouse Electric Corp. | Grooved visco seal for stationary discharge chamber of water-cooled turbine generator |
US4556261A (en) * | 1982-10-21 | 1985-12-03 | Lucas Industries Public Limited Company | Hydraulic anti-skid braking systems for vehicles |
US4893473A (en) * | 1988-01-21 | 1990-01-16 | Lucas Industries Public Limited Company | Reservoir-formed shoulder stop for makeup fluid valve actuation in pull-type master cylinder |
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US5695197A (en) * | 1996-12-06 | 1997-12-09 | Farley; Michael L. | Seal ring method of sealing and molding composition comprising blend of PTFE copolymer, polyamide and carbon fiber therefor |
US5865350A (en) * | 1997-01-24 | 1999-02-02 | Pure Vision International L.L.P. | Spray bottle with built-in pump |
US6514058B1 (en) * | 2001-07-20 | 2003-02-04 | Wen San Chou | Compressor having an improved valved piston device |
US6671966B2 (en) * | 2001-10-23 | 2004-01-06 | Calvin R. MacKay | Hydraulic and pneumatic actuated cutting apparatus |
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US20060275165A1 (en) * | 2003-10-03 | 2006-12-07 | Wilke Westley J | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
US7104613B2 (en) | 2004-07-28 | 2006-09-12 | Kelsey-Hayes Company | Pump with reciprocating high pressure seal and valve for vehicle braking systems |
US20060106740A1 (en) * | 2004-11-12 | 2006-05-18 | General Electric Company | Creation and correction of future time interval power generation curves for power generation costing and pricing |
US8708669B1 (en) * | 2007-02-12 | 2014-04-29 | Brunswick Corporation | Fuel pumping system |
WO2010037555A1 (en) * | 2008-10-02 | 2010-04-08 | Hydac Electronic Gmbh | Spool valve |
US20110227014A1 (en) * | 2010-03-16 | 2011-09-22 | Lautzenhiser Lloyd L | Hydraulic pumpling cylinder and method of pumping hydraulic fluid |
US9617129B2 (en) * | 2010-03-16 | 2017-04-11 | Brookefield Hunter, Inc. | Hydraulic pumping cylinder and method of pumping hydraulic fluid |
CN102918292A (en) * | 2010-05-27 | 2013-02-06 | 威伯科有限公司 | Device having a molded seal |
US9109704B2 (en) | 2010-05-27 | 2015-08-18 | Wabco Gmbh | Compressed-air control device with molded seal |
CN102918292B (en) * | 2010-05-27 | 2016-02-10 | 威伯科有限公司 | With the device of molded seals |
WO2011147494A1 (en) * | 2010-05-27 | 2011-12-01 | Wabco Gmbh | Device having a molded seal |
US20120186443A1 (en) * | 2011-01-20 | 2012-07-26 | Schaeffler Technologies AG & Co. KG | Piston assembly with a stamped orifice |
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WO2014198267A1 (en) * | 2013-06-10 | 2014-12-18 | Schaeffler Technologies Gmbh & Co. Kg | Piston/cylinder arrangement for a hydraulic disengagement device, in particular a master cylinder for a hydraulic shift actuating device |
CN105283686A (en) * | 2013-06-10 | 2016-01-27 | 舍弗勒技术股份两合公司 | Piston/cylinder arrangement for a hydraulic disengagement device, in particular a master cylinder for a hydraulic shift actuating device |
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Legal Events
Date | Code | Title | Description |
---|---|---|---|
AS | Assignment |
Owner name: KELSEY-HAYES COMPANY, MICHIGAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HOOL, PATRICK H.;SECHLER, JAMES;REEL/FRAME:014582/0672 Effective date: 20031003 |
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AS | Assignment |
Owner name: JPMORGAN CHASE BANK, N.A., NEW YORK Free format text: SECURITY INTEREST;ASSIGNORS:KELSEY-HAYES COMPANY;TRW AUTOMOTIVE U.S. LLC;TRW VEHICLE SAFETY SYSTEMS INC.;REEL/FRAME:015991/0001 Effective date: 20050124 Owner name: JPMORGAN CHASE BANK, N.A.,NEW YORK Free format text: SECURITY INTEREST;ASSIGNORS:KELSEY-HAYES COMPANY;TRW AUTOMOTIVE U.S. LLC;TRW VEHICLE SAFETY SYSTEMS INC.;REEL/FRAME:015991/0001 Effective date: 20050124 |
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STCB | Information on status: application discontinuation |
Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION |