Snowmobile

Patent metadata

Field	Value
Publication number	US-9610986-B2
Application number	US-201414339180-A
Country	US
Kind code	B2
Filing date	Jul 23, 2014
Priority date	Aug 1, 2011
Publication date	Apr 4, 2017
Grant date	Apr 4, 2017

Abstract

A drive apparatus for a track of a snowmobile includes a drive shaft and a drive sprocket coupled to the drive shaft. The drive sprocket includes a first drive member having a plurality of teeth configured to engage drive lugs on an inner surface of the track and a second drive member having plurality of teeth configured to enter the openings formed in the track upon rotation of the drive shaft. First and second connecting webs extend between the teeth of the first and second drive members, respectively. The first and second connecting webs each have first and second side angled surfaces aligned an angle of less than 180° relative to each other to minimize snow build up on the first and second drive members, respectively.

First claim

What is claimed is:

1. A drive apparatus for an endless track of a snowmobile, the track having an outer surface and an inner surface, a plurality of tread lugs extending outwardly from the outer surface, a plurality of drive lugs extending inwardly from the inner surface, and a plurality of openings, the drive apparatus comprising:
a drive shaft having a hexagonal-shaped cross-section extending along a longitudinal axis, the drive shaft including a plurality of ribs extending radially outward from the hexagonal-shaped cross-section and extending along a substantial length of the drive shaft in a direction of the longitudinal axis; and
a drive sprocket coupled to the drive shaft, the drive sprocket including:
a pair of outer drive members, each outer drive member including a body portion having a center opening located over the drive shaft, a plurality of teeth extending generally parallel to the longitudinal axis of the drive shaft, a first connecting web extending between each of the teeth of outer drive member, and the plurality of teeth of the outer drive members being configured to engage the drive lugs on the inner surface of the track to move the track upon rotation of the drive shaft, and the first connecting web having first and second side angled surfaces aligned at an angle of less than 180° relative to each other to minimize snow build up on the outer drive members, and
a center drive member located between the outer drive members, the center drive member including a body portion having a center opening located over the drive shaft, a plurality of teeth extending radially outwardly from the body portion of the center drive member transverse to the longitudinal axis of the drive shaft, and a second connecting web extending between each of the teeth of the center drive member, the plurality of teeth of the center drive member being configured to enter the openings formed in the track upon rotation of the drive shaft, and the second connecting web also having first and second side angled surfaces aligned an angle of less than 180° relative to each other to minimize snow build up on the center drive member,
wherein the center openings of each of the drive members has a hexagonally-shaped cross-section and includes a plurality of grooves extending radially outward from the hexagonally-shaped cross-section and aligned with the plurality of ribs on the drive shaft, and each of the grooves extends along an entire width of the center openings.

2. The apparatus of claim 1 , wherein the first and second side angled surfaces of the first and second connecting webs are aligned an angle of less than or equal to 90° relative to each other.

3. The apparatus of claim 1 , wherein the first and second connecting webs each include a top flat surface located between the first and second side angled surfaces.

4. The apparatus of claim 1 , wherein the outer drive members each include a plurality of ramped surfaces extending from body portion of the outer drive members to the plurality of teeth to reduce snow build up adjacent the teeth of the outer drive members.

5. The apparatus of claim 1 , wherein the outer drive members have a first radius to an outer surface of the plurality of teeth of the outer drive members and the center drive member has a second radius to an outer surface of the plurality of teeth of the center drive member, the second radius being 15% to 23% larger than the first radius to optimize ratcheting control for the drive sprocket.

6. The apparatus of claim 5 , wherein the teeth of center drive member are configured to engage edges defining the openings in the track if the teeth of outer drive member begin to slip over the drive lugs.

7. The apparatus of claim 1 , wherein the first and second side angled surfaces of the second connecting web extend from a lower surface of each of the plurality of teeth of the center drive member and are positioned radially outward from the body portion of the center drive member.

8. A drive apparatus for an endless track of a snowmobile, the track having an outer surface and an inner surface, a plurality of tread lugs extending outwardly from the outer surface, a plurality of drive lugs extending inwardly from the inner surface, and a plurality of openings, the drive apparatus comprising:
a drive shaft having a hexagonal-shaped cross-section extending along a longitudinal axis, the drive shaft including a plurality of ribs extending radially outward from the hexagonal-shaped cross-section and extending along a substantial length of the drive shaft in a direction of the longitudinal axis; and
a drive sprocket coupled to the drive shaft, the drive sprocket including a body portion having a center opening located over the drive shaft, a plurality of teeth configured to engage the track to move the track upon rotation of the drive shaft, and a connecting web extending between each of the plurality of teeth, the connecting web having first and second side angled surfaces aligned at an angle of less than 180° relative to each other to minimize snow build up on the drive sprocket, and an interface between the body portion and the connecting web being curved, wherein the center opening of the drive sprocket has a hexagonally-shaped cross-section and includes a plurality of grooves extending radially outward from the hexagonally-shaped cross-section and aligned with the plurality of ribs on the drive shaft, and each of the grooves extends along an entire width of the center opening.

9. The apparatus of claim 8 , wherein the plurality of teeth extend generally parallel to the longitudinal axis of the drive shaft and are configured to engage the drive lugs on the inner surface of the track to move the track upon rotation of the drive shaft.

10. The apparatus of claim 8 , wherein the plurality of teeth extend radially outwardly from the body portion transverse to the longitudinal axis of the drive shaft and are configured to enter the openings formed in the track upon rotation of the drive shaft.

11. The apparatus of claim 8 , wherein the first and second side angled surfaces of the connecting web are aligned an angle of 90° relative to each other.

12. The apparatus of claim 8 , wherein the first and second side angled surfaces of the connecting web are aligned an angle of less than 90° relative to each other.

13. The apparatus of claim 8 , wherein the connecting web includes a top flat surface located between the first and second side angled surfaces.

14. The apparatus of claim 8 , wherein the drive sprocket further includes a plurality of ramped surfaces extending from body portion to the plurality of teeth to reduce snow build up adjacent the teeth.

Assignees

• Polaris Inc

Inventors

• Conn Jeffrey D

Classifications

• B62D55/125

  Final drives · CPC title

• B62D55/244

  Moulded in one piece, with either smooth surfaces or surfaces having projections, e.g. incorporating reinforcing elements · CPC title

• B62M2027/026

  Snow mobiles characterised by the suspension means · CPC title

• B62D55/07

  Mono-track vehicles · CPC title

• B62D55/108

  with mechanical springs, e.g. torsion bars · CPC title