Torsional force linear tensioner
A linear tensioner driven by a torque input is provided having a base, a pinion rotatably mounted on the base, a rack operatively engaged with the pinion, an arm slideably mounted on the base and coupled to the rack for linear movement therewith, and a pulley rotatably mounted on the arm to engage and tension an associated power transmitting element such as a belt or chain. The tensioner further includes a means for applying a rotational force to the pinion, which may be, for example, a torsion spring, a servo motor or a hydraulic pump.
1 . A tensioner for tensioning a power transmitting element, the tensioner comprising:
a rotatable element; and
a translating element operatively engaged with the rotatable element so that rotation of the rotatable element in a first rotational direction causes translation of the translating element in a first linear direction to tension the power transmitting element and so that translation of the translating element in a second linear direction causes rotation of the rotatable element in a second rotational direction.
2 . A tensioner as claimed in claim 1 , wherein the rotatable element is a pinion and the translating element is a rack.
3 . A tensioner as claimed in claim 1 , wherein the rotatable element is a friction wheel in frictional contact with the translating element.
4 . A tensioner as claimed in claim 1 , further comprising a rotary actuator for applying a rotational force to the rotatable element.
5 . A tensioner as claimed in claim 1 , further comprising a means for applying a rotational force to the rotatable element.
6 . A tensioner as claimed in claim 5 , wherein the means for applying a rotational force to the rotatable element is a torsion spring.
7 . A tensioner as claimed in claim 5 , wherein the means for applying a rotational force to the rotating member is a servo motor.
8 . A tensioner as claimed in claim 5 , wherein the means for applying a rotational force to the rotating member is a hydraulic pump.
9 . A tensioner as claimed in claim 2 , further comprising an intermediate gear operatively engaged with the rack and the pinion so that the pinion indirectly engages the rack through the intermediate gear.
10 . A tensioner as claimed in claim 4 , further comprising a pulley rotatably coupled to the translating element for movement therewith, the pulley being operable to engage and tension the associated power transmitting element.
11 . A tensioner for tensioning a power transmitting element, the tensioner comprising:
a rotatable element; and
a translating element operatively engaged with the rotatable element so that rotation of the rotatable element in a first rotational direction causes translation of the translating element in a first linear direction;
wherein the translating element is capable of translating in a second linear direction opposite the first linear direction in response to force exerted by the associated power transmitting element.
12 . A tensioner as claimed in claim 11 , further comprising a cable having a first end coupled to the translating element and a second end coupled the rotatable element, wherein the rotatable element is a spool.
13 . A tensioner as claimed in claim 11 , wherein the rotatable element is a friction wheel in frictional contact with the translating element.
14 . A tensioner as claimed in claim 11 , wherein translation of the translating element in the second linear direction causes the rotatable element to rotate in a second rotational direction.
15 . A tensioner as claimed in claim 14 , wherein the rotatable element is a pinion and the translating element is a rack.
16 . A tensioner as claimed in claim 11 , further comprising a rotary actuator for biasing the rotatable element to rotate in the first rotational direction.
17 . A tensioner as claimed in claim 11 , further comprising a means for biasing the rotatable element to rotate in the first rotational direction.
18 . A tensioner as claimed in claim 17 , wherein the means for biasing is a torsion spring.
19 . A tensioner as claimed in claim 17 , wherein the means for biasing is a servo motor.
20 . A tensioner as claimed in claim 17 , wherein the means for biasing is a hydraulic pump.
21 . A tensioner as claimed in claim 16 , further comprising a pulley rotatably coupled to the translating element for movement therewith, the pulley being operable to engage and tension the associated power transmitting element.
22 . A tensioner for tensioning a power transmitting element, the tensioner comprising:
a base;
a pinion rotatably mounted on the base;
a means for applying a rotational force to the pinion;
a rack operatively engaged with the pinion;
an arm slideably mounted on the base and coupled to the rack for linear movement therewith; and
a pulley rotatably mounted on the arm to engage and tension the associated power transmitting element.
23 . A tensioner as claimed in claim 22 , wherein the means for applying a rotational force is a torsion spring.
24 . A tensioner as claimed in claim 22 , wherein the means for applying a rotational force is a servo motor.
25 . A tensioner as claimed in claim 22 , wherein the means for applying a rotational force is a hydraulic pump.
26 . A tensioner as claimed in claim 22 , further comprising an intermediate gear rotatably mounted on the base and operatively engaged with both the rack and the pinion.
27 . A tensioner as claimed in claim 22 , further comprising:
a second rack operatively engaged with the pinion;
a second arm slideably mounted on the base and coupled to the second rack for linear movement therewith; and
a second pulley rotatably mounted on the second arm to engage and tension an associated power transmitting element.
28 . A tensioner for tensioning a power transmitting element, the tensioner comprising:
a base;
a pinion rotatably mounted on the base;
a spring operatively coupled to the base and the pinion;
a rack operatively engaged with the pinion; and
a pulley rotatably mounted on the rack to engage and tension the associated power transmitting element.
29 . A tensioner as claimed in claim 28 , further comprising an intermediate gear rotatably mounted on the base and operatively engaged with both the rack and the pinion.
30 . A tensioner as claimed in claim 28 , further comprising:
a second rack operatively engaged with the pinion; and
a second pulley rotatably mounted on the second rack to engage and tension the associated power transmitting element.
31 . A tensioner for tensioning a power transmitting element, the tensioner comprising:
a base;
a pinion rotatably mounted on the base;
a means for applying a rotational force to the pinion;
a rack operatively engaged with pinion such that rotation of the pinion causes linear translation of the rack;
a pulley rotatably coupled to the rack for linear movement therewith, the pulley being operable to engage and tension the associated power transmitting element; and
a planetary gear set operatively coupling the pinion and the means for applying a rotational force to the pinion.
32 . A tensioner for tensioning a power transmitting element, the tensioner comprising:
a base;
a sun gear rotatably mounted on the base;
a means for applying a rotational force to the sun gear;
a ring gear concentric with the sun gear and non-rotatably mounted on the base;
a planetary gear operatively engaged with the sun gear and the ring gear such that rotation of the sun gear causes orbital movement of the planetary gear about the sun gear;
a pinion co-axially mounted with respect the sun gear for independent rotation, the pinion coupled to the planetary gear such that orbital movement of the planetary gear causes rotation of the pinion;
a rack operatively engaged with the pinion such that rotation of the pinion causes linear translation of the rack; and
a pulley rotatably coupled to the rack for linear movement therewith, the pulley being operable to engage and tension the associated power transmitting element.
33 . A tensioner as claimed in claim 32 , wherein the means for applying a rotational force is a torsion spring.
34 . A tensioner as claimed in claim 32 , wherein the means for applying a rotational force is a servo motor.
35 . A tensioner as claimed in claim 32 , wherein the means for applying a rotational force is a hydraulic pump.
36 . A tensioner for tensioning a power transmitting element, the tensioner comprising
a base;
a friction wheel rotatably mounted on the base;
a rotary actuator for applying a rotational force to the friction wheel;
an arm slideably mounted on the base and frictionally engaged with the friction wheel; and
a pulley rotatably coupled to the arm for movement therewith, the pulley operable to engage and tension the associated power transmitting element.
37 . A tensioner as claimed in claim 36 , wherein the rotary actuator is a torsion spring operatively coupled at a first end to the base and at a second end to the friction wheel.
38 . A tensioner for tensioning a power transmitting element, the tensioner comprising:
a base;
a spool rotatably mounted on the base;
a rotary actuator for applying a rotational force to the spool;
an arm slideably mounted on the base;
a cable coupled at a first end to the arm and coupled at a second end to the spool so as to be in winding engagement with the spool; and
a pulley rotatably coupled to the arm for movement therewith, the pulley operable to engage and tension the associated power transmitting element.
39 . A tensioner for tensioning a power transmitting element, the tensioner comprising:
a rotatable element; and
a translating element operatively engaged with the rotatable element so that rotation of the rotatable element causes translation of the translating element;
wherein the tensioner is operable in a first condition and a second condition, the first condition characterized by the rotatable element rotating in a first rotational direction and the translating element translating in a first linear direction, and the second condition characterized by the translating element translating in a second linear direction opposite the first linear direction and the rotatable element rotating in a second rotational direction.
40 . A tensioner as claimed in claim 39 , further comprising a rotary actuator for biasing the rotatable element to rotate in the first rotational direction.
41 . A tensioner as claimed in claim 40 , wherein the rotary actuator resists rotation of the rotatable member in the second rotational direction.