Snowmobile having a gearbox

Patent metadata

Field	Value
Publication number	US-11220310-B2
Application number	US-202016747118-A
Country	US
Kind code	B2
Filing date	Jan 20, 2020
Priority date	Jun 28, 2019
Publication date	Jan 11, 2022
Grant date	Jan 11, 2022

Abstract

A snowmobile has a gearbox having a first shaft, a second shaft, first transmission gears mounted to the first shaft and second transmission gears mounted to the second shaft. A driven gear mounted to the first shaft engages a forward drive gear mounted to a countershaft. In a first configuration: the first shaft is coupled to the countershaft; when rotating, a driveshaft rotates in a same direction as the countershaft; and configurable portions of the countershaft and second shaft are free of gears. In a second configuration: the forward drive gear is in selective free-spin engagement with the countershaft; a reverse drive gear mounted to the configurable portion of the countershaft is in driving engagement with the countershaft; an actuator selectively transmits rotary motion from the countershaft to the gearbox; a reverse driven gear mounted to the configurable portion of the second shaft meshes with the reverse drive gear.

First claim

What is claimed is:

1. A snowmobile, comprising:
a frame;
at least one ski connected to the frame;
a rear suspension assembly connected to the frame;
a drive track disposed around the rear suspension assembly;
an internal combustion engine supported by the frame, the engine comprising a crankshaft;
a continuously variable transmission (CVT) operatively connected to the crankshaft, comprising:
a drive pulley operatively connected to the crankshaft;
a driven pulley; and
a transmission belt interconnecting the drive pulley and the driven pulley;

a countershaft connected to the driven pulley of the CVT;
a forward drive gear mounted to the countershaft;
a gearbox comprising:
a first shaft;
a second shaft extending parallel to the first shaft;
a plurality of gears mounted to the first shaft, including:
a plurality of first transmission gears; and
a driven gear engaging the forward drive gear;

a plurality of second transmission gears mounted to the second shaft,
each of the first transmission gears being in constant mesh with a corresponding one of the second transmission gears to form a plurality of gear pairings including a high gear pairing and a low gear pairing,
for each of the high and low gear pairings:
a given one of the first and second transmission gears being in selective free-spin engagement with a corresponding one of the first shaft and the second shaft to which the given one of the first and second transmission gears is mounted,
an other one of the first and second transmission gears being in fixed engagement with a corresponding one of the first shaft and the second shaft to which the other one of the first and second transmission gears is mounted; and

a housing enclosing the first and second transmission gears therein and rotatably supporting the first shaft and the second shaft, the countershaft partly extending within the housing and rotatably supported thereby,
a configurable portion of the countershaft extending laterally between the forward drive gear and an inner wall of the housing,
a configurable portion of the second shaft being laterally aligned with the configurable portion of the countershaft;

a driveshaft coupled to the second shaft of the gearbox, the driveshaft being operatively connected to the drive track to propel the snowmobile; and
a shifter operable by a user for selectively operating the gearbox in one of a high gear, a low gear and a neutral gear, such that:
when the gearbox operates in the high gear, the shifter engages the given one of the first and second transmission gears corresponding to the high gear pairing to cause driving engagement thereof with the corresponding one of the first shaft and the second shaft;
when the gearbox operates in the low gear, the shifter engages the given one of the first and second transmission gears corresponding to the low gear pairing to cause driving engagement thereof with the corresponding one of the first shaft and the second shaft; and
when the gearbox operates in the neutral gear, the shifter is disengaged from the first and second transmission gears so that the given one of the first and second transmission gears of each of the high and low gear pairings remains in free-spin engagement with the corresponding one of the first shaft and the second shaft,

the snowmobile being configured according to one of a first configuration and a second configuration, wherein:
in the first configuration:
the forward drive gear is rotationally fixed to the countershaft;
the driven gear is rotationally fixed to the first shaft;
the driven gear is in rotational engagement with the forward drive gear so that the first shaft is coupled to the countershaft;
when rotating, the driveshaft rotates in a same direction as the countershaft; and
the configurable portions of the countershaft and the second shaft are free of gears;

and
in the second configuration:
the forward drive gear is in selective free-spin engagement with the countershaft;
the snowmobile further comprises:
a reverse drive gear mounted to the countershaft at the configurable portion of the countershaft, the reverse drive gear being in driving engagement with the countershaft; and
an actuator for selectively transmitting rotary motion from the countershaft to the gearbox via a selected one of the forward drive gear and the reverse drive gear;

the gearbox further comprises a reverse driven gear mounted to the second shaft at the configurable portion of the second shaft, enclosed within the housing of the gearbox, and configured to mesh with the reverse drive gear;
when the selected one of the forward drive gear and the reverse drive gear is the forward drive gear:
when rotating, the driveshaft rotates in the same direction as the countershaft; and
the gearbox is operable in one of the high gear, the low gear and the neutral gear;

and
when the selected one of the forward drive gear and the reverse drive gear is the reverse drive gear:
when rotating, the driveshaft rotates in a reverse direction opposite to a direction of rotation of the countershaft.

2. The snowmobile of claim 1 , wherein the gearbox further comprises:
a driving sprocket fixedly mounted to the second shaft and enclosed within the housing of the gearbox;
an output sprocket fixedly mounted to the driveshaft and enclosed within the housing of the gearbox; and
a flexible driving member drivingly connecting the driving sprocket to the output sprocket so as to transmit rotary motion from the second shaft to the driveshaft.

3. The snowmobile of claim 2 , wherein the flexible driving member is a chain.

4. The snowmobile of claim 1 , wherein:
the given one of the first and second transmission gears of each of the high and low gear pairings in selective free-spin engagement with the corresponding one of the first shaft and the second shaft is the first transmission gears such that:
the first transmission gears are in selective free-spin engagement with the first shaft; and
the second transmission gears are in fixed engagement with the second shaft.

5. The snowmobile of claim 4 , wherein the shifter comprises:
a shifter knob movable between a high gear position, a low gear position and a neutral gear position corresponding to the high gear, the low gear and the neutral gear of the gearbox respectively;
a dog mounted on the first shaft and slidable along an axis of the first shaft, the dog comprising dog teeth; and
a plurality of links interconnecting the dog to the shifter knob,
wherein:
each of the first transmission gears has dog teeth matching the dog teeth of the dog;
when the shifter knob is moved to the high gear position, the dog engages the dog teeth of the first transmission gear corresponding to the high gear pairing;
when the shifter knob is moved to the low gear position, the dog engages the dog teeth of the first transmission gear corresponding to the low gear pairing; and
when the shifter knob is moved to the neutral gear position, the dog is disengaged from the first transmission gears.

6. The snowmobile of claim 5 , wherein, in the neutral gear position of the shifter knob, the dog is mounted on the first shaft between the first transmission gear corresponding to the high gear pairing and the first transmission gear corresponding to the low gear pairing.

7. The snowmobile of claim 1 , wherein the housing of the gearbox comprises a left housing portion and a right housing portion, the left and right housing portions being affixed to one another.

8. The snowmobile of claim 1 , wherein:
the first shaft defines a first shaft axis about which the first shaft is rotatable;
the second shaft defines a second shaft axis about which the second shaft is rotatable; and

Assignees

• Bombardier Recreational Products Inc

Inventors

• Pard Jean-Sebastien
• Pitre Joel
• Nolet Yan

Classifications

• B62M11/06

  with spur gear wheels (B62M11/14 takes precedence) · CPC title

• B62M2027/027

  Snow mobiles characterised by the tracks · CPC title

• F16H2702/00

  Combinations of two or more transmissions · CPC title

• B62M2027/025

  Snow mobiles characterised by the skis · CPC title

• B62M2027/023

  Snow mobiles characterised by engine mounting arrangements · CPC title