PARKING INTERLOCK DEVICE FOR AN AUTOMOTIVE TRANSMISSION

• US 20120097497A1
• Filed: 10/20/2011
• Published: 04/26/2012
• Est. Priority Date: 10/26/2010
• Status: Active Grant

• Current Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: ZF Friedrichshafen AG (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: LIST, Matthias, AUSTERMANN, Bernd, MILLER, Tobias, KATZORECK, Karl-Hermann, BREITWEG, Thomas, RASCH, Armin
• Granted Patent: US 8,579,099 B2
• Time in Patent Office: Days
• US Class Current: 192/219.5
• CPC Class Codes: F16H 63/3425 characterised by pawls or wheels
• CPC Class Codes: Y10T 74/2137 Single tooth

Abstract

A transmission parking lock device comprising a gearwheel with teeth and gaps and a pawl having a pawl tooth. The gearwheel rotates and the pawl pivots about axes that are parallel to each other. The gearwheel teeth each have a first contour and tooth flanks with respect to rotation of the gearwheel. The pawl tooth has a second contour and tooth flanks relative to the rotation of the gearwheel, and the gearwheel has an outer radius. The gearwheel and pawl are kinematically linked by a linear relationship between the pivoting and rotational angles. The first and/or second contour are at least partially circular with a radius of the outer radius of the gearwheel, and the teeth and/or the pawl tooth have, in the area of the front tooth flank of the gearwheel or parking lock pawl, a crown tip relief relative to the outer radius of the gearwheel.

Claims

1-12. -12. (canceled)

13. A parking lock device for a motor vehicle, the parking lock device comprising:

a parking lock gearwheel (1) with teeth (3) and tooth gaps (4) and a parking lock pawl (2) with a pawl tooth (5),

the parking lock gearwheel (1) undergoing a rotation movement with rotation angle (φ

) and rotational speed (φ

-dot) about a rotational axis and the parking lock pawl (2) undergoes a pivoting movement with pivoting angle (ω

) and pivoting speed (ω

-dot) around a pivot axis arranged parallel to the rotational axis;

such that above a predefined drop-in speed, the parking lock pawl (2) is rejected by the teeth (3) of the parking lock gearwheel (1) and therefore undergoes an oscillating pivoting movement (known as ratcheting); and

the parking lock gearwheel (1) and the parking lock pawl (2) are kinematically linked with one another by a linear relationship between the pivoting angle (ω

) and the rotational angle (φ

).

14. A parking lock device for a motor vehicle transmission, the parking lock device comprising:

a parking lock gearwheel (1) with teeth (3) and tooth gaps (4) and a parking lock pawl (2) with a pawl tooth (5);

the parking lock gearwheel (1) undergoing a rotation movement with rotation angle (φ

) and rotational speed (φ

-dot) about a rotational axis and the parking lock pawl (2) undergoing a pivoting movement with pivoting angle (ω

) and pivoting speed (ω

-dot) around a pivot axis arranged parallel to the rotation axis;

the teeth (3, 13) of the parking lock gearwheel (1) each have a first contour (13a) and front and rear tooth flanks (13b, 13c) as viewed in a rotational direction (D) of the parking lock gearwheel (1);

the pawl tooth (5, 15) having a second contour (15a) and front and rear tooth flanks (15b, 15c) relative to the rotational direction (D) of the parking lock gearwheel (1);

and the parking lock gearwheel (1) having an outer radius (r_aR);

at least one of the first and the second contours (13a, 15a) being formed at least partially in accordance with a mathematical function, whose curvature does not differ by more than 20% from an outer curvature of the parking lock gearwheel (1) which is defined as a reciprocal value of the outer radius (r_aR) of the parking lock gearwheel (1); and

at least one of the teeth (13) and the pawl tooth (15) having a crown tip relief (δ

) relative to the outer radius (r_aR) of the parking lock gearwheel (1) in an area of the front tooth flank (13b, 15b) of the at least one of the parking lock gearwheel (1) and the parking lock pawl (2).

15. The parking lock device according to claim 14, wherein the mathematical function defines a circle with a radius that differs from the outer radius (r_aR) of the parking lock gearwheel (1) by at most 20%.

16. The parking lock according to claim 14, wherein the mathematical function defines an ellipse with semi-axes that differ from the outer radius (r_aR) of the parking lock gearwheel (1) by at most 20%.

18. The parking lock device according to claim 14, wherein the crown tip relief (δ

) comprises a fraction (δ

_R) for the teeth (13) of the parking lock gearwheel (1) and a fraction (δ

_K) for the pawl tooth (15).

19. The parking lock device according to claim 18, wherein the fractions (δ

_R, δ

_K) of the crown tip relief (6) for the teeth (13) and for the pawl tooth (15) are their tooth widths (φ

_R, φ

_K).

20. The parking lock device according to claim 14, wherein at least one of the teeth (13) and the pawl tooth (15) have a crown tip relief, in an area of the rear tooth flank (13c, 15c), which merges into circular arc sections.

23. The parking lock device according to claim 14, wherein the first contour (13a) is of convex shape in relation to the rotational axis (M_R).

24. The parking lock device according to claim 14, wherein the second contour (13a) is of concave shape in relation to the rotational axis (M_R).

17. A parking lock device for a motor vehicle transmission, the parking lock device comprising:

a parking lock gearwheel (1) with teeth (3) and tooth gaps (4) and a parking lock pawl (2) with a pawl tooth (5);

the parking lock gearwheel (1) undergoing rotational movement with rotation angle (φ

) and rotational speed (φ

-dot) about a rotational axis and the parking lock pawl (2) undergoes a pivoting movement with pivoting angle (ω

) and pivoting speed (ω

-dot) around a pivot axis that is parallel to the rotational axis;

the teeth (3, 13) of the parking lock gearwheel (1) each having a first contour (13a) and front and rear tooth flanks (13b, 13c) when viewed in a rotational direction (D) of the parking lock gearwheel (1);

the pawl tooth (5, 15) having a second contour (15a) and front and rear tooth flanks (15b, 15c) relative to the rotational direction (D) of the parking lock gearwheel (1);

the parking lock gearwheel (1) having an outer radius (r_aR);

at least one of the first and the second contours (13a, 15a) being formed at least partially in accordance with a mathematical function, whose curvature does not differ by more than 20% from an outer curvature of the parking lock gearwheel (1) which is defined as a reciprocal value of the outer radius (r_aR) of the parking lock gearwheel (1); and

at least one of the teeth (13) and the pawl tooth (15) have a crown tip relief (δ

) relative to the outer radius (r_aR) of the parking lock gearwheel (1) in an area of the front tooth flank (13b, 15b) of a respective one of at the parking lock gearwheel (1) and the parking lock pawl (2).

21. The parking lock device according to claim 17, wherein at least one of the first and the second contour (13a, 15a) has a radius of curvature (r_K) which is in the range of 0.8 (r_aR)≦

radius of curvature (r_K)≦

1.2 (r_aR), where (r_aR) is the outer radius of the parking lock gearwheel.

22. The parking lock device according to claim 21, wherein the radius of curvature (r_K) of the at least one of the first and the second contours (13a, 15a) is equal to the outer radius (r_aR) of the parking lock gearwheel.