WO2016108846A1 - Releasable pumping plunger retractor for fuel injection pump - Google Patents

Releasable pumping plunger retractor for fuel injection pump Download PDF

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Publication number
WO2016108846A1
WO2016108846A1 PCT/US2014/072761 US2014072761W WO2016108846A1 WO 2016108846 A1 WO2016108846 A1 WO 2016108846A1 US 2014072761 W US2014072761 W US 2014072761W WO 2016108846 A1 WO2016108846 A1 WO 2016108846A1
Authority
WO
WIPO (PCT)
Prior art keywords
retainer
lock collar
diameter portion
fuel pump
coupler
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.)
Ceased
Application number
PCT/US2014/072761
Other languages
French (fr)
Inventor
Anthony A. Shaull
Anthony D. Smith
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Cummins Inc
Original Assignee
Cummins Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Cummins Inc filed Critical Cummins Inc
Priority to PCT/US2014/072761 priority Critical patent/WO2016108846A1/en
Publication of WO2016108846A1 publication Critical patent/WO2016108846A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
    • F02M59/10—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by the piston-drive
    • F02M59/102—Mechanical drive, e.g. tappets or cams
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/44—Details, components parts, or accessories not provided for in, or of interest apart from, the apparatus of groups F02M59/02 - F02M59/42; Pumps having transducers, e.g. to measure displacement of pump rack or piston
    • F02M59/445—Selection of particular materials
    • 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
    • F04B1/0426—Arrangements for pressing the pistons against the actuated cam; Arrangements for connecting the pistons to the actuated cam
    • 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
    • F04B1/0439—Supporting or guiding means for the pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/03—Fuel-injection apparatus having means for reducing or avoiding stress, e.g. the stress caused by mechanical force, by fluid pressure or by temperature variations
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M2200/00—Details of fuel-injection apparatus, not otherwise provided for
    • F02M2200/90—Selection of particular materials
    • F02M2200/9015—Elastomeric or plastic materials
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M59/00—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps
    • F02M59/02—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type
    • F02M59/04—Pumps specially adapted for fuel-injection and not provided for in groups F02M39/00 -F02M57/00, e.g. rotary cylinder-block type of pumps of reciprocating-piston or reciprocating-cylinder type characterised by special arrangement of cylinders with respect to piston-driving shaft, e.g. arranged parallel to that shaft or swash-plate type pumps

Definitions

  • the invention relates generally to releasable mechanical assemblies.
  • Embodiments of the invention include a releasable pumping plunger retractor for fuel injection pumps.
  • Fuel injection pumps are generally known and disclosed, for example, in the Grant et al. U.S. Patent 8,070,464 and the Aritomi et al. U.S. Patent 8,671,914.
  • Pumps of these types include several cylinders, each having a spring-driven pumping plunger that reciprocates in a barrel bore.
  • the spring surrounds a portion of the pumping plunger and is coupled to the pumping plunger by a retractor assembly mounted to an end portion of the plunger. During a fill cycle the spring acts on the retractor assembly and pulls the plunger from the barrel.
  • a roller tappet driven by a lobe of a rotating camshaft engages the retractor assembly on a side opposite the pumping plunger and limits the motion of the retractor assembly and plunger during the fill cycle stroke (i.e., the spring and retractor assembly act to keep the roller tappet in contact with and following the camshaft lobe profile during the fill cycle).
  • the camshaft lobe and roller tappet act on the retractor assembly against the spring force to push the pumping plunger into the barrel.
  • the pumping plunger occasionally becomes stuck in the barrel bore.
  • One scenario involves the retractor assembly breaking and pulling from the pumping plunger.
  • the plunger and retractor can continue to create debris. Such a failure can lead to tappet damage, camshaft damage and lower bearing damage. It is also possible that damage from the lower end of the pump can enter the engine oil sump and create further complications.
  • the retractor does not break and is able to retain the spring load instead of transferring that load to the roller tappet. The roller tappet is then in a no-follow condition which may lead to damage of the roller tappet and camshaft lobe, which can continue with progressive damage to the lower pump assembly.
  • Embodiments of the invention include an assembly comprising a fuel pump plunger having a longitudinal axis and a plunger retractor connected to the fuel pump plunger.
  • the plunger retractor can release from the plunger without generating debris that might cause progressive damage.
  • the plunger retractor comprises a spring retainer, a retainer coupler connected to the spring retainer, and a lock collar.
  • the spring retainer has an inner diameter portion with a tapered surface.
  • the retainer coupler is configured for limited movement with respect to the spring retainer about an axis perpendicular to the longitudinal axis of the pump plunger, and is formed from a first material such as metal.
  • the lock collar has an inner diameter portion surrounding and engaging the fuel pump plunger and an outer diameter portion with a tapered surface engaging the tapered surface of the inner diameter portion of the retainer coupler to form a locking taper coupling the lock collar and the retainer coupler.
  • the lock collar is formed from a second material, such as a polymer, that is relatively compressible or otherwise deformable with respect to the first material of the retainer coupler.
  • the lock collar compresses or otherwise deforms, engages the fuel pump plunger and releases from the retainer coupler.
  • a fuel pump body including a barrel bore, a camshaft having a cam lobe, a roller tappet coupling the cam lobe to the plunger retractor, and a return spring.
  • the fuel pump plunger is located in the barrel bore, and the fuel pump plunger and plunger retractor reciprocally move between a retracted position and an extended position.
  • the return spring is engaged with the spring retainer to bias the plunger retractor and fuel pump plunger from the extended position toward the retracted position with a force greater than the release force.
  • FIG. 1 is a cross sectional view of a multi-cylinder fuel pump including releasable pumping plunger retractors in accordance with embodiments of the invention.
  • FIG. 2 is a detailed illustration of a portion of the fuel pump shown in FIG. 1, showing the pumping plunger retractor engaged with the pumping plunger.
  • FIG. 3 is an isometric view of the spring retainer shown in FIG. 2.
  • FIG. 4 is an isometric view of the lock collar shown in FIG. 2.
  • FIG. 5 is an isometric view of the retainer coupler shown in FIG. 2.
  • FIG. 6 is a detailed illustration of the portion of the fuel pump and pumping plunger shown in FIG. 2, showing the pumping plunger retractor released from the pumping plunger.
  • FIG. 7 is a detailed illustration of a portion of a fuel pump showing a pumping plunger retractor in accordance with other embodiments of the invention.
  • FIG. 8 is an isometric view of the lock collar shown in FIG. 7.
  • a fuel injection pump 8 including releasable pumping plunger retractor assemblies 10 in accordance with embodiments of the invention is shown in FIG. 1.
  • fuel injection pump 8 can be of conventional or otherwise known design.
  • the illustrated embodiment of pump 8 includes a body 12 in which a camshaft 14 is rotatably mounted.
  • Camshaft 14 includes lobes 17 and is driven by a drive gear 16 mounted to an end thereof.
  • Motion provided by the profiles of the lobes 17 during rotation of the camshaft 14 is coupled to the pumping plunger retractor assemblies 10 by roller tappet assemblies 19.
  • the embodiment shown in FIG. 1 has two fuel pump cylinders 15, although other embodiments can have more or fewer cylinders.
  • Each fuel pump cylinder 15 includes a pumping plunger retractor assembly 10 mounted within a pumping barrel 18 that includes a pumping chamber 20 and a pumping plunger 22.
  • the pumping plungers 22, which can for example be metal or ceramic members, are driven by pumping plunger retractor assemblies 10 and reciprocate within the pumping chambers 20 between retracted and extended positions during fill and pumping strokes.
  • a biasing member such as return spring 21 in each cylinder 15 applies a return force to the pumping plunger retractor assembly 10 with respect to the pumping barrel 18 to urge the pumping plunger retractor assembly toward the retracted position and into engagement with the roller tappet assembly 19.
  • the return springs 2 cause the pumping plunger retractors 10 to contact the roller tappet assemblies 19 as the roller tappet assemblies move in response to the rotation of the camshaft 14 and its lobes 17.
  • the pumping plunger 22 in the left pump cylinder 15 is in the extended position
  • the pumping plunger 22 in the right pump cylinder 15 is in the retracted position.
  • An inlet metering valve 24, low pressure supply pump 26 and an inlet and outlet check valve assembly 28 on each cylinder 15, are also shown in FIG. 1.
  • Other embodiments (not shown) have metering valves located in place of the inlet check valves (i.e., active inlet metering).
  • FIG. 2 is a detailed illustration of a portion of the injection pump 8, showing a pumping plunger retractor assembly 10, roller tappet assembly 19, pumping plunger 22 and return spring 21.
  • Roller tappet assembly 19 includes a roller 30 rotatably secured to a shell 32 by a pin 34.
  • the roller tappet shell 32 is a cup-shaped member that receives the pumping plunger retractor assembly 10.
  • the illustrated embodiment of pumping plunger retractor assembly 10 includes a spring retainer 40, lower spring retainer 42, retainer ring or coupler 44 and lock wedge or collar 46.
  • the spring retainer 40 is located within the roller tappet shell 32 and includes a side wall 48, an inwardly extending lip 50, and an outwardly extending flange 54. As shown in FIGs.
  • the lip 50 on the spring retainer 40 defines a central opening 52 having an inner diameter.
  • the lower spring retainer 42 includes a central portion 56 within the spring retainer 40, and an outwardly extending flange 58 that extends between the flange 54 of the spring retainer 40 and the bottom of the roller tappet shell 32. As shown, the end of the return spring 21 extends around the side wall 48 and engages the flange 54 of the spring retainer 40.
  • Spring retainer 40 is a metal member in some embodiments. Other embodiments of the spring retainer 40 are formed from other materials, such as polymers.
  • the retainer coupler 44 and lock collar 46 releasably connect the pumping plunger 22 to the spring retainer 40.
  • the retainer coupler 44 is an annular member having a neck 60 with an inner surface 62 defining an inner diameter, and an outwardly extending flange 64.
  • the outer diameter of the retainer coupler neck 60 is less than the inner diameter of the spring retainer central opening 52
  • the outer diameter of the retainer coupler flange 64 is greater than the inner diameter of the spring retainer central opening and less than the inner diameter of the spring retainer side wall 48.
  • Retainer coupler 44 is formed from material that has elasticity, compliance and other parameters that characterize its resistance to being deformed (either permanently or non- permanently) in response to the application of force.
  • the retainer coupler 44 is a metal member (e.g., steel) in some embodiments.
  • Other embodiments of the retainer coupler 44 are formed from other materials such as polymers.
  • the lock collar 46 is an annular member having an outer surface 70 defining an outer diameter and an inner surface 72 defining an inner diameter that engages an outer wall of the pumping plunger 22.
  • the outer diameter of the lock collar outer surface 70 is about equal to the inner diameter of the retainer coupler inner surface 62.
  • the inner surface 72 includes a flat walled portion 74 that engages a flat walled portion 75 on the outer diameter portion of the pumping plunger 22, and an inwardly extending lip 76 that is received in and engages a complimentary-shaped annular recess 77 in the outer diameter portion of the pumping plunger.
  • the lock collar 46 is formed from a material that has elasticity, compliance and other parameters that characterize its resistance to being compressed or otherwise deformed (either permanently or non-permanently) in response to the application of force. As described in greater detail below, lock collar 46 is formed from material that enables the structure to be more compressible or otherwise deformable that the retainer coupler 44.
  • the lock collar 46 is a polymer (e.g., Nylon or poly ether ketone (PEEK)) in some embodiments, and is formed from other materials in other embodiments. In the embodiment shown in FIG. 4, the lock collar 46 has a gap 79 extending therethrough to facilitate assembly of the lock collar onto the pumping plunger 22.
  • the entire inner surface 72 of the lock collar 46 is flat and engaged with flat walled portions such as 75 on the outer diameter portion of the pumping plunger 22 (i.e., these embodiments do not have the complimentary shaped lip 76 and recess 77).
  • the interface between the retainer coupler inner surface 62 and the lock collar outer surface 70 forms a releasable connection between the components.
  • the surfaces 62 and 70 are complimentary flat and tapered surfaces that extend at nonzero angles with respect to an axis parallel the longitudinal axis of the pumping plunger 22.
  • the lock collar retains engagement to both the fuel pump plunger 22 and the retainer coupler.
  • the lock collar compresses or otherwise deforms with respect to the retainer coupler, engages the fuel pump plunger 22, and releases from the spring retainer.
  • the taper angle of the surfaces 62 and 70 of the retainer coupler 44 and lock collar 46, respectively is about 7° with respect to the longitudinal axis of the pumping plunger 22. Other embodiments have other taper angles.
  • the taper angle can, for example, depend upon factors such as the shapes, sizes, and materials (i.e., and therefore elasticities and deformation characteristics) of the retainer coupler 44 and lock collar 46 and the desired release force.
  • the taper angle is between 6° and 8°. Yet other embodiments have larger and smaller taper angles.
  • plunger retractor assemblies 10 are configured to provide a release force that is less than the return force provided by the return springs 21, but greater than the forces required of the pumping plunger 22 when moving from the extended position to the retracted position during fill cycles of the pump 8.
  • a pumping plunger 22 may stick or seize within a barrel 18 at a location between the extended and retracted positions.
  • the return force of the return spring 21 acting on the spring retainer 40 will be greater than the release force provided by the retainer coupler 44 and lock collar 46.
  • the lock collar 46 will therefore engage the pumping plunger 22 and compress or otherwise deform as described above, allowing the retainer coupler 44 to and release from and be pulled away from the lock collar.
  • the retainer coupler 44 and spring retainer 40 will then continue to follow the roller tappet assembly 19 and camshaft lobe 17 as shown in FIG. 6.
  • the lock collar 46 is retained on the pumping plunger 22, and during the next pumping stroke of the spring retainer 40 and retainer coupler 44, the lock collar will be pushed up the pumping plunger and away from the spring retainer.
  • the retainer coupler 44 is contained within the spring retainer 40 by the lower spring retainer 42.
  • Releasable pumping plunger retractor assembly 10 offers a number of important advantages. Although the associated pump cylinder 15 is dead and non-functional upon the release of the retractor assembly 10 from the plunger 22, all the components of the plunger retractor assembly are contained, so further damage to the pump 8 or the engine (not shown) with which the pump is mounted, including possible progressive damage, is minimized or eliminated. In fuel pumps such as 8 having several pump cylinders 15, other remaining and operative pump cylinders can provide sufficient fuel to enable vehicles on which the pump is located to operate and be driven to a service center. Furthermore, it has been demonstrated that lock collars formed from non-metallic material, such as polymer, will not damage the lower assembly. Such a material, if destroyed into debris during operation of the pump, would be captured by the engine lube filter.
  • retractor assembly 10 Another advantage of retractor assembly 10 is that the spring retainer 40 and the retainer coupler 44 are configured for limited movement with respect to one another about an axis perpendicular to the longitudinal axis of the pump plunger 22.
  • the range of movement between the spring retainer 40 and the retainer coupler 44 is constrained by the engagement of either or both of the retainer coupler neck 60 and the spring retainer lip 50 and the retainer coupler flange 64 and the spring retainer side wall 48.
  • the limited or constrained movement of the retainer coupler 44 with respect to the spring retainer 40 provides a degree of "float” to minimize or reduce side loading of the pumping plunger 22 within the pumping barrel 18 by any horizontal motion the spring retainer (i.e., in a direction perpendicular to the longitudinal axis of the plunger) during operation of the pump 8.
  • This feature can be particularly advantageous in pumps 8 having ceramic pumping plungers 22.
  • Yet another advantage of the pumping plunger retractor assembly 10 is that the locking taper provided by the retainer coupler 44 and the lock collar 46 can hold the components together sufficiently well during assembly of pump 8 to enhance the manufacturability of the pump.
  • FIGs. 7 and 8 illustrate portions of a fuel injection pump 108 having a releasable pumping plunger retractor assembly 110 in accordance with yet other embodiments of the invention.
  • the releasable pumping plunger assembly 110 does not have a retainer coupler 44. Instead, the releasable locking taper coupler functionality is provided by the lip 151 of the spring retainer 140 and the lock collar 146.
  • the fuel injection pump 108 can be the same as or similar to that of pump 8, and similar components are identified by similar reference numbers.
  • the spring retainer 140 includes a neck 151 that extends upwardly from a shoulder 150.
  • the neck 151 has an inner surface 162 defining an inner diameter.
  • Lock collar 146 is an annular member having an outer surface 170 defining an outer diameter and an inner surface 172 defining an inner diameter that engages an outer wall of the pumping plunger 122.
  • the outer diameter of the lock collar outer surface 170 is about equal to the inner diameter of the spring retainer inner surface 162.
  • the inner surface 172 includes inwardly extending, annular lips 173 that engage a flat walled portion 175 on the outer diameter portion of the pumping plunger 122.
  • lock collar 146 is formed from a material that has elasticity, compliance and other parameters that characterize its resistance to being deformed (either permanently or non-permanently) in response to the application of force.
  • Lock collar 146 is formed from material that enables the structure to be more compressible or otherwise deformable that the neck 151 or other portions of the spring retainer 140.
  • the lock collar 146 is a polymer (e.g., Nylon or poly ether ketone (PEEK)) in some embodiments, and is formed from other materials in other embodiments.
  • PEEK poly ether ketone
  • the lock collar 146 is split and has a gap 179 extending therethrough to facilitate assembly of the lock collar onto the pumping plunger 122.
  • the interface between the spring retainer inner surface 162 and the lock collar outer surface 170 forms a releasable connection between the components.
  • the surfaces 162 and 170 are complimentary flat and tapered surfaces that extend at non-zero angles with respect to an axis parallel the longitudinal axis of the pumping plunger 122.
  • the lock collar retains engagement to both the fuel pump plunger 122 and the spring retainer.
  • the lock collar compresses or otherwise deforms with respect to the spring retainer, engages the fuel pump plunger 122 and releases from the spring retainer.
  • the taper angle of the surfaces 162 and 170 are about 7° with respect to the longitudinal axis of the pumping plunger 122.
  • Other embodiments have other taper angles.
  • the taper angle can, for example, depend upon factors such as the shapes, sizes, and materials (i.e., and therefore elasticities and deformation characteristics) of the spring retainer 140 and lock collar 146 and the desired release force.
  • the taper angle is between 6° and 8°.
  • Yet other embodiments have larger and smaller taper angles.
  • Releasable pumping plunger retractor assembly 110 provides advantages similar to those of retractor assembly 10 described above.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Fuel-Injection Apparatus (AREA)

Abstract

An assembly comprising a fuel pump plunger and a plunger retractor. The plunger retractor includes a spring retainer, a metal retainer coupler connected to the spring retainer, and a polymer lock collar. The retainer coupler has an inner diameter portion with a tapered surface, 5 and is configured for limited movement with respect to the spring retainer about an axis perpendicular to a longitudinal axis of the pump plunger.

Description

RELEASABLE PUMPING PLUNGER RETRACTOR
FOR FUEL INJECTION PUMP
FIELD OF THE INVENTION
The invention relates generally to releasable mechanical assemblies. Embodiments of the invention include a releasable pumping plunger retractor for fuel injection pumps.
BACKGROUND
Fuel injection pumps are generally known and disclosed, for example, in the Grant et al. U.S. Patent 8,070,464 and the Aritomi et al. U.S. Patent 8,671,914. Pumps of these types include several cylinders, each having a spring-driven pumping plunger that reciprocates in a barrel bore. The spring surrounds a portion of the pumping plunger and is coupled to the pumping plunger by a retractor assembly mounted to an end portion of the plunger. During a fill cycle the spring acts on the retractor assembly and pulls the plunger from the barrel. A roller tappet driven by a lobe of a rotating camshaft engages the retractor assembly on a side opposite the pumping plunger and limits the motion of the retractor assembly and plunger during the fill cycle stroke (i.e., the spring and retractor assembly act to keep the roller tappet in contact with and following the camshaft lobe profile during the fill cycle). During a pumping cycle the camshaft lobe and roller tappet act on the retractor assembly against the spring force to push the pumping plunger into the barrel. In pumps of these types the pumping plunger occasionally becomes stuck in the barrel bore. A number of different failure scenarios are possible during a seizure of this type. One scenario involves the retractor assembly breaking and pulling from the pumping plunger. If the seizure is mid-stroke, the plunger and retractor can continue to create debris. Such a failure can lead to tappet damage, camshaft damage and lower bearing damage. It is also possible that damage from the lower end of the pump can enter the engine oil sump and create further complications. In another scenario the retractor does not break and is able to retain the spring load instead of transferring that load to the roller tappet. The roller tappet is then in a no-follow condition which may lead to damage of the roller tappet and camshaft lobe, which can continue with progressive damage to the lower pump assembly. There remains, therefore, a continuing need for improved fuel injection pumps and components. In particular, there is a need for a pump that is not susceptible to further or progressive damage in the event of a pumping plunger seizure. Such a pump that can continue to operate on another cylinder and enable the vehicle on which the pump is present to be driven to a repair facility would be especially desirable.
SUMMARY
Embodiments of the invention include an assembly comprising a fuel pump plunger having a longitudinal axis and a plunger retractor connected to the fuel pump plunger. The plunger retractor can release from the plunger without generating debris that might cause progressive damage. In embodiments, the plunger retractor comprises a spring retainer, a retainer coupler connected to the spring retainer, and a lock collar. The spring retainer has an inner diameter portion with a tapered surface. The retainer coupler is configured for limited movement with respect to the spring retainer about an axis perpendicular to the longitudinal axis of the pump plunger, and is formed from a first material such as metal. The lock collar has an inner diameter portion surrounding and engaging the fuel pump plunger and an outer diameter portion with a tapered surface engaging the tapered surface of the inner diameter portion of the retainer coupler to form a locking taper coupling the lock collar and the retainer coupler. The lock collar is formed from a second material, such as a polymer, that is relatively compressible or otherwise deformable with respect to the first material of the retainer coupler. Upon the application of forces less than a release force between the fuel pump plunger and the spring retainer in a direction causing the locking taper to couple the lock collar and retainer coupler, the lock collar retains engagement to both the fuel pump plunger and the retainer coupler. Upon the application of forces greater than or equal to the release force between the fuel pump plunger and the retainer coupler in a direction causing the locking taper to couple the lock collar and retainer coupler, the lock collar compresses or otherwise deforms, engages the fuel pump plunger and releases from the retainer coupler.
Other embodiments of the invention include a fuel pump body including a barrel bore, a camshaft having a cam lobe, a roller tappet coupling the cam lobe to the plunger retractor, and a return spring. The fuel pump plunger is located in the barrel bore, and the fuel pump plunger and plunger retractor reciprocally move between a retracted position and an extended position. The return spring is engaged with the spring retainer to bias the plunger retractor and fuel pump plunger from the extended position toward the retracted position with a force greater than the release force. BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross sectional view of a multi-cylinder fuel pump including releasable pumping plunger retractors in accordance with embodiments of the invention.
FIG. 2 is a detailed illustration of a portion of the fuel pump shown in FIG. 1, showing the pumping plunger retractor engaged with the pumping plunger.
FIG. 3 is an isometric view of the spring retainer shown in FIG. 2.
FIG. 4 is an isometric view of the lock collar shown in FIG. 2.
FIG. 5 is an isometric view of the retainer coupler shown in FIG. 2.
FIG. 6 is a detailed illustration of the portion of the fuel pump and pumping plunger shown in FIG. 2, showing the pumping plunger retractor released from the pumping plunger.
FIG. 7 is a detailed illustration of a portion of a fuel pump showing a pumping plunger retractor in accordance with other embodiments of the invention.
FIG. 8 is an isometric view of the lock collar shown in FIG. 7.
DETAILED DESCRIPTION
A fuel injection pump 8 including releasable pumping plunger retractor assemblies 10 in accordance with embodiments of the invention is shown in FIG. 1. With the exception of the pumping plunger retractor assemblies 10, fuel injection pump 8 can be of conventional or otherwise known design. For example, the illustrated embodiment of pump 8 includes a body 12 in which a camshaft 14 is rotatably mounted. Camshaft 14 includes lobes 17 and is driven by a drive gear 16 mounted to an end thereof. Motion provided by the profiles of the lobes 17 during rotation of the camshaft 14 is coupled to the pumping plunger retractor assemblies 10 by roller tappet assemblies 19. The embodiment shown in FIG. 1 has two fuel pump cylinders 15, although other embodiments can have more or fewer cylinders. Each fuel pump cylinder 15 includes a pumping plunger retractor assembly 10 mounted within a pumping barrel 18 that includes a pumping chamber 20 and a pumping plunger 22. The pumping plungers 22, which can for example be metal or ceramic members, are driven by pumping plunger retractor assemblies 10 and reciprocate within the pumping chambers 20 between retracted and extended positions during fill and pumping strokes. A biasing member such as return spring 21 in each cylinder 15 applies a return force to the pumping plunger retractor assembly 10 with respect to the pumping barrel 18 to urge the pumping plunger retractor assembly toward the retracted position and into engagement with the roller tappet assembly 19. During normal operation of the pump 8, the return springs 2 cause the pumping plunger retractors 10 to contact the roller tappet assemblies 19 as the roller tappet assemblies move in response to the rotation of the camshaft 14 and its lobes 17. In the embodiment shown in FIG. 1, the pumping plunger 22 in the left pump cylinder 15 is in the extended position, and the pumping plunger 22 in the right pump cylinder 15 is in the retracted position. An inlet metering valve 24, low pressure supply pump 26 and an inlet and outlet check valve assembly 28 on each cylinder 15, are also shown in FIG. 1. Other embodiments (not shown) have metering valves located in place of the inlet check valves (i.e., active inlet metering).
FIG. 2 is a detailed illustration of a portion of the injection pump 8, showing a pumping plunger retractor assembly 10, roller tappet assembly 19, pumping plunger 22 and return spring 21. Roller tappet assembly 19 includes a roller 30 rotatably secured to a shell 32 by a pin 34. The roller tappet shell 32 is a cup-shaped member that receives the pumping plunger retractor assembly 10. The illustrated embodiment of pumping plunger retractor assembly 10 includes a spring retainer 40, lower spring retainer 42, retainer ring or coupler 44 and lock wedge or collar 46. The spring retainer 40 is located within the roller tappet shell 32 and includes a side wall 48, an inwardly extending lip 50, and an outwardly extending flange 54. As shown in FIGs. 2 and 3, the lip 50 on the spring retainer 40 defines a central opening 52 having an inner diameter. The lower spring retainer 42 includes a central portion 56 within the spring retainer 40, and an outwardly extending flange 58 that extends between the flange 54 of the spring retainer 40 and the bottom of the roller tappet shell 32. As shown, the end of the return spring 21 extends around the side wall 48 and engages the flange 54 of the spring retainer 40. Spring retainer 40 is a metal member in some embodiments. Other embodiments of the spring retainer 40 are formed from other materials, such as polymers.
The retainer coupler 44 and lock collar 46 releasably connect the pumping plunger 22 to the spring retainer 40. In the embodiment shown in FIGs. 2 and 5, the retainer coupler 44 is an annular member having a neck 60 with an inner surface 62 defining an inner diameter, and an outwardly extending flange 64. As discussed in greater detail below, the outer diameter of the retainer coupler neck 60 is less than the inner diameter of the spring retainer central opening 52, and the outer diameter of the retainer coupler flange 64 is greater than the inner diameter of the spring retainer central opening and less than the inner diameter of the spring retainer side wall 48. Retainer coupler 44 is formed from material that has elasticity, compliance and other parameters that characterize its resistance to being deformed (either permanently or non- permanently) in response to the application of force. The retainer coupler 44 is a metal member (e.g., steel) in some embodiments. Other embodiments of the retainer coupler 44 are formed from other materials such as polymers.
In the embodiment shown in FIGs. 2 and 4, the lock collar 46 is an annular member having an outer surface 70 defining an outer diameter and an inner surface 72 defining an inner diameter that engages an outer wall of the pumping plunger 22. As is discussed in greater detail below, the outer diameter of the lock collar outer surface 70 is about equal to the inner diameter of the retainer coupler inner surface 62. In the illustrated embodiment, the inner surface 72 includes a flat walled portion 74 that engages a flat walled portion 75 on the outer diameter portion of the pumping plunger 22, and an inwardly extending lip 76 that is received in and engages a complimentary-shaped annular recess 77 in the outer diameter portion of the pumping plunger. The lock collar 46 is formed from a material that has elasticity, compliance and other parameters that characterize its resistance to being compressed or otherwise deformed (either permanently or non-permanently) in response to the application of force. As described in greater detail below, lock collar 46 is formed from material that enables the structure to be more compressible or otherwise deformable that the retainer coupler 44. The lock collar 46 is a polymer (e.g., Nylon or poly ether ketone (PEEK)) in some embodiments, and is formed from other materials in other embodiments. In the embodiment shown in FIG. 4, the lock collar 46 has a gap 79 extending therethrough to facilitate assembly of the lock collar onto the pumping plunger 22. In yet other embodiments (not shown), the entire inner surface 72 of the lock collar 46 is flat and engaged with flat walled portions such as 75 on the outer diameter portion of the pumping plunger 22 (i.e., these embodiments do not have the complimentary shaped lip 76 and recess 77).
The interface between the retainer coupler inner surface 62 and the lock collar outer surface 70 forms a releasable connection between the components. In the embodiment shown in FIG. 2, the surfaces 62 and 70 are complimentary flat and tapered surfaces that extend at nonzero angles with respect to an axis parallel the longitudinal axis of the pumping plunger 22. By this configuration of the surfaces 62 and 70, the retainer coupler 44 and lock collar 46 form a form a locking taper or self-holding coupler. In response to the application of forces less than a release force between the retainer coupler 44 and lock collar 46 in a direction tending to cause the locking taper to engage and couple the spring retainer and lock collar (i.e., in a direction causing the retainer coupler to move toward the roller tappet assembly 19 with respect to the lock collar in the illustrated embodiment), the lock collar retains engagement to both the fuel pump plunger 22 and the retainer coupler. However, because of the relative deformation characteristics of the components, upon the application of forces greater than or equal to the release force between the retainer coupler 44 and lock collar 46 in a direction causing the locking taper to couple the spring retainer and lock collar, the lock collar compresses or otherwise deforms with respect to the retainer coupler, engages the fuel pump plunger 22, and releases from the spring retainer. In embodiments, the taper angle of the surfaces 62 and 70 of the retainer coupler 44 and lock collar 46, respectively, is about 7° with respect to the longitudinal axis of the pumping plunger 22. Other embodiments have other taper angles. The taper angle can, for example, depend upon factors such as the shapes, sizes, and materials (i.e., and therefore elasticities and deformation characteristics) of the retainer coupler 44 and lock collar 46 and the desired release force. For example, in some embodiments the taper angle is between 6° and 8°. Yet other embodiments have larger and smaller taper angles.
The operation of plunger retractor assemblies 10 can be described with reference to FIG. 6. Pumping plunger retractor assemblies 10 are configured to provide a release force that is less than the return force provided by the return springs 21, but greater than the forces required of the pumping plunger 22 when moving from the extended position to the retracted position during fill cycles of the pump 8. During the operation of fuel injection pump 8, a pumping plunger 22 may stick or seize within a barrel 18 at a location between the extended and retracted positions. On the occurrence of a failure of this type, the return force of the return spring 21 acting on the spring retainer 40 will be greater than the release force provided by the retainer coupler 44 and lock collar 46. The lock collar 46 will therefore engage the pumping plunger 22 and compress or otherwise deform as described above, allowing the retainer coupler 44 to and release from and be pulled away from the lock collar. The retainer coupler 44 and spring retainer 40 will then continue to follow the roller tappet assembly 19 and camshaft lobe 17 as shown in FIG. 6. As is also shown in FIG. 6, the lock collar 46 is retained on the pumping plunger 22, and during the next pumping stroke of the spring retainer 40 and retainer coupler 44, the lock collar will be pushed up the pumping plunger and away from the spring retainer. The retainer coupler 44 is contained within the spring retainer 40 by the lower spring retainer 42. Separation of the pumping plunger 22 from the spring retainer 40 occurs without the breakage of metal parts and the generation of metallic debris. Releasable pumping plunger retractor assembly 10 offers a number of important advantages. Although the associated pump cylinder 15 is dead and non-functional upon the release of the retractor assembly 10 from the plunger 22, all the components of the plunger retractor assembly are contained, so further damage to the pump 8 or the engine (not shown) with which the pump is mounted, including possible progressive damage, is minimized or eliminated. In fuel pumps such as 8 having several pump cylinders 15, other remaining and operative pump cylinders can provide sufficient fuel to enable vehicles on which the pump is located to operate and be driven to a service center. Furthermore, it has been demonstrated that lock collars formed from non-metallic material, such as polymer, will not damage the lower assembly. Such a material, if destroyed into debris during operation of the pump, would be captured by the engine lube filter.
Another advantage of retractor assembly 10 is that the spring retainer 40 and the retainer coupler 44 are configured for limited movement with respect to one another about an axis perpendicular to the longitudinal axis of the pump plunger 22. In particular, the range of movement between the spring retainer 40 and the retainer coupler 44 is constrained by the engagement of either or both of the retainer coupler neck 60 and the spring retainer lip 50 and the retainer coupler flange 64 and the spring retainer side wall 48. The limited or constrained movement of the retainer coupler 44 with respect to the spring retainer 40 provides a degree of "float" to minimize or reduce side loading of the pumping plunger 22 within the pumping barrel 18 by any horizontal motion the spring retainer (i.e., in a direction perpendicular to the longitudinal axis of the plunger) during operation of the pump 8. This feature can be particularly advantageous in pumps 8 having ceramic pumping plungers 22. Yet another advantage of the pumping plunger retractor assembly 10 is that the locking taper provided by the retainer coupler 44 and the lock collar 46 can hold the components together sufficiently well during assembly of pump 8 to enhance the manufacturability of the pump.
FIGs. 7 and 8 illustrate portions of a fuel injection pump 108 having a releasable pumping plunger retractor assembly 110 in accordance with yet other embodiments of the invention. As shown, unlike retractor assembly 10 described above, the releasable pumping plunger assembly 110 does not have a retainer coupler 44. Instead, the releasable locking taper coupler functionality is provided by the lip 151 of the spring retainer 140 and the lock collar 146. Other than these differences which are described in greater detail below, the fuel injection pump 108 can be the same as or similar to that of pump 8, and similar components are identified by similar reference numbers.
As shown, the spring retainer 140 includes a neck 151 that extends upwardly from a shoulder 150. The neck 151 has an inner surface 162 defining an inner diameter. Lock collar 146 is an annular member having an outer surface 170 defining an outer diameter and an inner surface 172 defining an inner diameter that engages an outer wall of the pumping plunger 122. The outer diameter of the lock collar outer surface 170 is about equal to the inner diameter of the spring retainer inner surface 162. In the illustrated embodiment, the inner surface 172 includes inwardly extending, annular lips 173 that engage a flat walled portion 175 on the outer diameter portion of the pumping plunger 122. Like the lock collar 46 described in connection with pump 8, lock collar 146 is formed from a material that has elasticity, compliance and other parameters that characterize its resistance to being deformed (either permanently or non-permanently) in response to the application of force. Lock collar 146 is formed from material that enables the structure to be more compressible or otherwise deformable that the neck 151 or other portions of the spring retainer 140. The lock collar 146 is a polymer (e.g., Nylon or poly ether ketone (PEEK)) in some embodiments, and is formed from other materials in other embodiments. In the embodiment shown in FIG. 8, the lock collar 146 is split and has a gap 179 extending therethrough to facilitate assembly of the lock collar onto the pumping plunger 122.
The interface between the spring retainer inner surface 162 and the lock collar outer surface 170 forms a releasable connection between the components. In the embodiment shown in FIGs. 7 and 8, the surfaces 162 and 170 are complimentary flat and tapered surfaces that extend at non-zero angles with respect to an axis parallel the longitudinal axis of the pumping plunger 122. By this configuration the surfaces 162 and 170 of the spring retainer 140 and lock collar 146, respectively, form a locking taper or self-holding coupler. In response to the application of forces less than a release force between the spring retainer 140 and lock collar 146 in a direction causing the locking taper to couple the spring retainer and lock collar (i.e., in a direction causing the spring retainer to move toward the roller tappet assembly 119 with respect to the lock collar in the illustrated embodiment), the lock collar retains engagement to both the fuel pump plunger 122 and the spring retainer. However, because of the relative deformation characteristics of the components, upon the application of forces greater than or equal to the release force between the spring retainer 140 and lock collar 146 in a direction causing the locking taper to couple the spring retainer and lock collar, the lock collar compresses or otherwise deforms with respect to the spring retainer, engages the fuel pump plunger 122 and releases from the spring retainer. In embodiments, the taper angle of the surfaces 162 and 170 are about 7° with respect to the longitudinal axis of the pumping plunger 122. Other embodiments have other taper angles. The taper angle can, for example, depend upon factors such as the shapes, sizes, and materials (i.e., and therefore elasticities and deformation characteristics) of the spring retainer 140 and lock collar 146 and the desired release force. For example, in some embodiments the taper angle is between 6° and 8°. Yet other embodiments have larger and smaller taper angles. Releasable pumping plunger retractor assembly 110 provides advantages similar to those of retractor assembly 10 described above.
Although the invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.

Claims

What is claimed is: 1. An assembly, comprising:
a fuel pump plunger; and
a plunger retractor connected to the fuel pump plunger, comprising:
a spring retainer having an inner diameter portion with a tapered surface, the spring retainer formed from a first material; and
a lock collar having an inner diameter portion surrounding and engaging the fuel pump plunger and an outer diameter portion with a tapered surface engaging the tapered surface of the inner diameter portion of the spring retainer to form a locking taper coupling the collar and the spring retainer, the lock collar formed from a second material that is relatively deformable with respect to the first material of the spring retainer; and wherein upon application of forces less than a release force between the fuel pump
plunger and the spring retainer in a direction causing the locking taper to couple the lock collar and spring retainer, the lock collar retains engagement to both the fuel pump plunger and the spring retainer; and
wherein upon application of forces greater than or equal to the release force between the fuel pump plunger and the spring retainer in a direction causing the locking taper to couple the lock collar and spring retainer, the lock collar deforms, engages the fuel pump plunger and releases from the spring retainer.
2. The assembly of claim 1 and further including:
a fuel pump body including a barrel bore, wherein the fuel pump plunger is located in the barrel bore, and the fuel pump plunger and plunger retractor reciprocally move between a retracted position and an extended position;
a camshaft having a cam lobe;
a roller tappet coupling the cam lobe to the plunger retractor; and
a return spring engaged with the spring retainer to bias the plunger retractor and fuel pump plunger from the extended position toward the retracted position with a force greater than the release force.
3. The assembly of claim 2 wherein:
the inner diameter portion of the spring retainer is circular with a flat tapered surface; and the outer diameter portion of the lock collar is circular with a flat tapered surface.
4. The assembly of claim 3 wherein:
the inner diameter portion of the spring retainer is metal; and
the lock collar is polymer.
5. The assembly of claim 4 wherein:
the inner diameter portion of the lock collar has a flat wall; and
an outer diameter portion of the fuel pump plunger engaged by the inner diameter portion of the lock collar has a flat wall.
6. The assembly of claim 4 wherein the inner diameter portion of the lock collar has a non-flat gripping surface.
7. The assembly of claim 6 wherein an outer diameter portion of the fuel pump plunger engaged by the inner diameter portion of the lock collar has a flat wall.
8. The assembly of claim 6 wherein an outer diameter portion of the fuel pump plunger engaged by the inner diameter portion of the lock collar has a non-flat wall.
9. The assembly of claim 4 wherein:
the inner diameter portion of the lock collar includes:
a portion with a flat wall; and
a portion with an inwardly extending projection such as an annular lip; and an outer diameter portion of the fuel pump plunger engaged by the inner diameter portion of the lock collar includes:
a portion with flat wall engaged by the flat wall of the lock collar; and
a recessed portion, such as an annular groove, engaged by the inwardly extending projection.
An assembly, comprising a fuel pump plunger having a longitudinal axis; and
a plunger retractor connected to the fuel pump plunger, comprising:
a spring retainer;
a retainer coupler connected to the spring retainer and having an inner diameter portion with a tapered surface, the retainer coupler configured for limited movement with respect to the spring retainer about an axis perpendicular to the longitudinal axis of the pump plunger, and formed from a first material; and
a lock collar having an inner diameter portion surrounding and engaging the fuel pump plunger and an outer diameter portion with a tapered surface engaging the tapered surface of the inner diameter portion of the retainer coupler to form a locking taper coupling the lock collar and the retainer coupler, the lock collar formed from a second material that is relatively deformable with respect to the first material of the retainer coupler; and wherein upon application of forces less than a release force between the fuel pump
plunger and the spring retainer in a direction causing the locking taper to couple the lock collar and retainer coupler, the lock collar retains engagement to both the fuel pump plunger and the retainer coupler; and
wherein upon application of forces greater than or equal to the release force between the fuel pump plunger and the retainer coupler in a direction causing the locking taper to couple the lock collar and retainer coupler, the lock collar compresses or otherwise deforms, engages the fuel pump plunger and releases from the retainer coupler.
11. The assembly of claim 10 and further including:
a fuel pump body including a barrel bore, wherein the fuel pump plunger is located in the barrel bore, and the fuel pump plunger and plunger retractor reciprocally move between a retracted position and an extended position;
a camshaft having a cam lobe;
a roller tappet coupling the cam lobe to the plunger retractor; and
a return spring engaged with the spring retainer to bias the plunger retractor and fuel pump plunger from the extended position toward the retracted position with a force greater than the release force.
12. The assembly of claim 11 wherein:
the inner diameter portion of the retainer coupler is circular with a flat tapered surface; and
the outer diameter portion of the lock collar is circular with a flat tapered surface.
13. The assembly of claim 12 wherein:
the inner diameter portion of the retainer coupler is metal; and
the lock collar is polymer.
14. The assembly of claim 13 wherein:
the inner diameter portion of the lock collar has a flat wall; and
an outer diameter portion of the fuel pump plunger engaged by the inner diameter portion of the lock collar has a flat wall.
15. The assembly of claim 13 wherein the inner diameter portion of the lock collar has a non-flat gripping surface.
16. The assembly of claim 15 wherein an outer diameter portion of the fuel pump plunger engaged by the inner diameter portion of the lock collar has a flat wall.
17. The assembly of claim 15 wherein an outer diameter portion of the fuel pump plunger engaged by the inner diameter portion of the lock collar has a non-flat wall.
18. The assembly of claim 13 wherein:
the inner diameter portion of the lock collar includes:
a portion with a flat wall; and
a portion with an inwardly extending projection such as an annular lip; and an outer diameter portion of the fuel pump plunger engaged by the inner diameter portion of the lock collar includes:
a portion with flat wall engaged by the flat wall of the lock collar; and a recessed portion, such as an annular groove, engaged by the inwardly extending projection.
19. The assembly of claim 13 wherein:
the spring retainer includes a side wall and a lip extending inwardly from the side wall and defining a central opening having a diameter; and
the retainer coupler includes a neck extending into the central opening and a shoulder having an outer diameter that is greater than the diameter of the central opening; and
wherein the limited movement between the retainer coupler and the spring retainer is constrained by one or both of (1) engagement of the retainer coupler neck with the spring retainer lip, and (2) engagement of the retainer coupler shoulder with the spring retainer side wall.
20. The assembly of claim 10 and including structures on one or both of the retainer coupler and the spring retainer to constrain the range of movement of the retainer coupler with respect to the spring retainer.
21. The assembly of claim 10 wherein:
the spring retainer includes a side wall and a lip extending inwardly from the side wall and defining a central opening having a diameter; and
the retainer coupler includes a neck extending into the central opening and a shoulder having an outer diameter that is greater than the diameter of the central opening; and
wherein the limited movement between the retainer coupler and the spring retainer is constrained by one or both of (1) engagement of the retainer coupler neck with the spring retainer lip, and (2) engagement of the retainer coupler shoulder with the spring retainer side wall.
22. An assembly, comprising:
a first element having a first axis; and
a second element connected to the first element, comprising:
a retainer;
a retainer coupler connected to the retainer and having an inner diameter portion with a tapered surface, the retainer coupler configured for limited movement with respect to the retainer about a second axis perpendicular to the first axis of the first element, and formed from a first material; and a lock collar having an inner diameter portion surrounding and engaging a portion of the first element and an outer diameter portion with a tapered surface engaging the tapered surface of the inner diameter portion of the retainer coupler to form a locking taper coupling the lock collar and the retainer coupler, the lock collar formed from a second material that is relatively compressible or otherwise deformable with respect to the first material of the retainer coupler; and
wherein upon application of forces less than a release force along the first axis between the first element and the retainer in a direction causing the locking taper to couple the lock collar and retainer coupler, the lock collar retains engagement to both the first element and the retainer coupler; and
wherein upon application of forces greater than or equal to the release force along the first axis between the first element and the retainer coupler in a direction causing the locking taper to couple the lock collar and retainer coupler, the lock collar compresses, engages the first element and releases from the retainer coupler.
PCT/US2014/072761 2014-12-30 2014-12-30 Releasable pumping plunger retractor for fuel injection pump Ceased WO2016108846A1 (en)

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PCT/US2014/072761 WO2016108846A1 (en) 2014-12-30 2014-12-30 Releasable pumping plunger retractor for fuel injection pump

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2014/072761 WO2016108846A1 (en) 2014-12-30 2014-12-30 Releasable pumping plunger retractor for fuel injection pump

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Cited By (1)

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WO2024013374A1 (en) * 2022-07-15 2024-01-18 Delphi Technologies Ip Limited Fuel pump for the direct-injection of fuel for internal combustion engines

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GB761405A (en) * 1954-06-15 1956-11-14 Valves Ltd Poppet valves
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US5520155A (en) * 1994-07-28 1996-05-28 Caterpillar Inc. Tappet and plunger assembly adapted for a fluid injection pump
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Publication number Priority date Publication date Assignee Title
WO2024013374A1 (en) * 2022-07-15 2024-01-18 Delphi Technologies Ip Limited Fuel pump for the direct-injection of fuel for internal combustion engines
FR3137945A1 (en) * 2022-07-15 2024-01-19 Delphi Technologies Ip Limited Fuel pump for direct fuel injection for internal combustion engines.

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