Two-speed accessory drive pulley

Patent metadata

Field	Value
Publication number	US-10830126-B2
Application number	US-201916456137-A
Country	US
Kind code	B2
Filing date	Jun 28, 2019
Priority date	Jun 29, 2018
Publication date	Nov 10, 2020
Grant date	Nov 10, 2020

Abstract

A two-speed pulley assembly for an engine accessory drive includes a planetary gear, a pulley, a friction clutch, a one-way clutch, and a torsional isolator. The planetary gear has a ring gear, a sun gear, a planet carrier and at least one planet gear. The planet carrier is arranged for driving engagement with an engine crankshaft. The pulley circumscribes the ring gear and is in driving engagement with the ring gear. The friction clutch is arranged to selectively prevent rotation of the sun gear. The one-way clutch permits rotation of the sun gear relative to the ring gear in a first rotational direction, and prevents rotation of the sun gear relative to the ring gear in a second rotational direction, opposite the first rotational direction. The torsional isolator is drivingly connected to the planet carrier and arranged to rotate at a same speed as the planet carrier.

First claim

What we claim is:

1. A two-speed pulley assembly for an engine accessory drive comprising:
an axis;
a planetary gear comprising:
a ring gear rotatable about the axis;
a sun gear;
a planet carrier arranged for driving engagement with an engine crankshaft and including at least one planetary pin, radially offset from the axis; and
at least one planet gear:
rotatable relative to the planet carrier about the at least one planetary pin; and
drivingly engaged with the ring gear and the sun gear;

a pulley circumscribing the ring gear and in driving engagement with the ring gear;
a friction clutch arranged to selectively prevent rotation of the sun gear;
a one-way clutch arranged between the sun gear and the ring gear that:
permits rotation of the sun gear relative to the ring gear in a first rotational direction; and
prevents rotation of the sun gear relative to the ring gear in a second rotational direction, opposite the first rotational direction; and

a torsional isolator drivingly connected to the planet carrier and arranged to rotate at a same speed as the planet carrier.

2. The two-speed pulley assembly of claim 1 wherein the torsional isolator is at least partially disposed axially between the pulley and an engine block.

3. The two-speed pulley assembly of claim 1 further comprising a crankshaft hub arranged for fixing to the engine crankshaft, wherein the planet carrier is drivingly engaged with the crankshaft hub by a face spline.

4. The two-speed pulley assembly of claim 3 further comprising a crankshaft balance weight installed on the crankshaft hub.

5. The two-speed pulley assembly of claim 1 further comprising:
a drive plate fixed to the planet carrier and including a drive plate spline; and
a bearing arranged in a radial space between the drive plate and the pulley.

6. The two-speed pulley assembly of claim 5 wherein the torsional isolator includes a torsional isolator spline drivingly engaged with the drive plate spline.

7. The two-speed pulley assembly of claim 1 wherein the ring gear and the pulley are integrated into a single component made from a single piece of material.

8. The two-speed pulley assembly of claim 1 wherein the friction clutch comprises:
an output plate arranged for fixing to an engine block, the output plate comprising a first conical surface;
a piston, drivingly engaged with the sun gear and comprising a second conical surface arranged for frictional engagement with the first conical surface; and
an electromagnet arranged to displace the piston in a first axial direction to frictionally engage the second conical surface with the first conical surface.

9. The two-speed pulley assembly of claim 8 further comprising a snap ring, wherein the sun gear comprises a sun gear hub with a sun gear hub groove and the snap ring is installed in the sun gear hub groove to limit an axial displacement of the piston a second axial direction, opposite the first axial direction.

10. The two-speed pulley assembly of claim 8 further comprising a resilient element arranged to displace the piston in a second axial direction, opposite the first axial direction, to disengage the second conical surface form the first conical surface.

11. The two-speed pulley assembly of claim 8 wherein the electromagnet is fixed to the output plate.

12. The two-speed pulley assembly of claim 8 wherein the pulley comprises a pulley outer diameter and the electromagnet comprises an electromagnet inner diameter, greater than the pulley outer diameter.

13. The two-speed pulley assembly of claim 8 wherein the first conical surface and the second conical surface are disposed radially outside of and at least partially axially aligned with the electromagnet.

14. The two-speed pulley assembly of claim 1 wherein the two-speed pulley assembly comprises a sealed chamber for filling with a lubricating oil.

15. The two-speed pulley assembly of claim 14 wherein the at least one planetary pin comprises a plurality of flow channels for distributing the lubricating oil.

Assignees

• Schaeffler Technologies Ag

Inventors

• Hrusch Nicholas
• Swank Michael

Classifications

• F16H1/2863

  Arrangements for adjusting or for taking-up backlash · CPC title

• F16D41/36

  with clutching ring or disc axially shifted as a result of lost motion between actuating members · CPC title

• F16H3/54

  one of the central gears being internally toothed and the other externally toothed · CPC title

• F16H2200/2066

  using one freewheel mechanism · CPC title

• F02B67/06 Primary

  driven by means of chains, belts, or like endless members · CPC title