Mechanical lifter

1. A mechanical lifter comprising:

an inner lift member at least partly made of a metallic material;

an outer lift member at least partly made of a polymeric material, the outer lift member surrounding the inner lift member;

a roller rotatably coupled with respect to the inner lift member, the roller being partly disposed within the inner lift member, wherein the inner lift member is configured to move a first component in response to a force applied to the roller by a second component; and

a shaft supporting the roller, wherein the shaft is fixed to the outer lift member, and at least a portion of the shaft is in direct contact with the outer lift member.

2. The mechanical lifter of claim 1 , wherein the mechanical lifter has a mass ranging between about 68 grams and about 72 grams.

3. The mechanical lifter of claim 2 , wherein the mechanical lifter has a mass of about 70 grams.

4. The mechanical lifter of claim 1 , wherein an entirety of the inner lift member is disposed inside the outer lift member.

5. The mechanical lifter of claim 1 , wherein the polymeric material includes a polyamide.

6. The mechanical lifter of claim 5 , wherein the polymeric material includes a glass filled polyamide.

7. The mechanical lifter of claim 5 , wherein the polymeric material includes a glass filled polyhexamethyleneadipamide.

8. The mechanical lifter of claim 6 , wherein the polymeric material includes a 30% glass filled polyhexamethyleneadipamide.

9. The mechanical lifter of claim 1 , wherein the outer lift member includes an outer lift body and a protrusion extending outwardly from the outer lift body, the protrusion being shaped and sized to be slidably received in a groove of a housing so as to inhibit rotation of the mechanical lifter relative to the housing.

10. The mechanical lifter of claim 9 , wherein the protrusion is monolithically formed with the outer lift body.

11. A vehicle comprising:

an engine configured to power the vehicle, the engine including an engine component;

a housing; and

a fuel pump assembly in fluid communication with the engine so as to supply fuel to the engine, the fuel pump assembly including:

a pump body affixed to the housing and defining a pump bore, the pump bore defining a stroke axis;

a plunger at least partly disposed in the pump bore, the plunger being operatively coupled to the pump body such that the plunger is configured to move relative to the pump bore along the stroke axis;

a mechanical lifter disposed within the housing, the mechanical lifter being operatively coupled to the plunger such that the plunger is configured to move relative to the pump bore along the stroke axis upon movement of the mechanical lifter relative to the housing, the mechanical lifter including:

an outer lift member including a polymeric material;

an inner lift member at least partly disposed within the outer lift member, the outer lift member being molded over the inner lift member;

a roller rotatably coupled with respect to the inner lift member, the roller being partly disposed within the inner lift member, wherein the engine component is configured to apply a force to the roller so as to move the mechanical lifter relative to the housing along the stroke axis; and

a shaft supporting the roller, wherein at least a portion of the shaft is in direct contact with the outer lift member.

12. The vehicle of claim 11 , wherein the mechanical lifter has a mass ranging between about 68 grams and about 72 grams.

13. The vehicle of claim 11 , wherein the mechanical lifter has a mass of about 70 grams.

14. The vehicle of claim 11 , wherein the polymeric material includes a polyamide.

15. The vehicle of claim 14 , wherein the polyamide is selected from a group consisting of polyhexamethyleneadipamide, poly-6-caprolactam, and a combination thereof.

16. The vehicle of claim 14 , wherein the polyamide is embedded with glass fibers.

17. The vehicle of claim 11 , wherein the housing has an inner housing surface and a groove that extends into the inner housing surface, and the outer lift member includes an outer lift body and a protrusion extending from the outer lift body, the protrusion being shaped and sized to be slidably received in the groove so as to inhibit rotation of the mechanical lifter about the stroke axis.

18. The vehicle of claim 11 , further comprising a shaft supporting the roller, wherein the shaft is directly fixed to the outer lift member.

19. A vehicle comprising:

an engine configured to power the vehicle, the engine including an engine component;

a housing; and

a fuel pump assembly in fluid communication with the engine so as to supply fuel to the engine, the fuel pump assembly including:

a pump body affixed to the housing and defining a pump bore, the pump bore defining a stroke axis;

a plunger at least partly disposed in the pump bore, the plunger being operatively coupled to the pump body such that the plunger is configured to move relative to the pump bore along the stroke axis;

a mechanical lifter disposed within the housing, the mechanical lifter being operatively coupled to the plunger such that the plunger is configured to move relative to the pump bore along the stroke axis upon movement of the mechanical lifter relative to the housing, the mechanical lifter including:

an outer lift member including a polymeric material;

an inner lift member at least partly disposed within the outer lift member, the outer lift member being molded over the inner lift member; and

a roller rotatably coupled with respect to the inner lift member, the roller being partly disposed within the inner lift member, wherein the engine component is configured to apply a force to the roller so as to move the mechanical lifter relative to the housing along the stroke axis; and

a shaft supporting the roller, wherein the shaft is directly fixed to the outer lift member.