HIGH-OFFSET BELT TENSIONER WITH COUNTERBALANCE TORSION SPRING FORCE
A high-offset belt tensioner has a base having a pivot tube that defines a first axis of rotation, an arm having a pivot tube-receiving body rotatably seated over the pivot tube and having a pulley pivot tube that defines a second axis of rotation. A torsion spring is seated around an exterior surface of the pivot tube-receiving body with a first spring end attached to the base and a second spring end oriented and seated in the pulley pivot tube. A pulley is seated on the pulley pivot tube and rotatable thereabout. A dust cover is seated on the pulley pivot tube juxtaposed to the pulley and a first end of the pivot tube is deformed toward the dust cover to retain the pulley without the use of a pulley bolt.
1 . A high-offset belt tensioner comprising:
a base having a pivot tube that defines a first axis of rotation;
an arm having an arm arbor rotatably seated over the pivot tube and having a pulley pivot tube that defines a second axis of rotation; and
a torsion spring seated around an exterior surface of the arm arbor with a first spring end attached to the base and a second spring end oriented and seated in the pulley pivot tube.
2 . A high-offset belt tensioner of claim 1 , further comprising a pulley seated on the pulley pivot tube and a means for fastening the pulley thereto.
3 . The high-offset belt tensioner of claim 1 , wherein the first end of the pulley pivot tube defines a socket opening, opposite the second spring end, that is configured to receive a tool.
4 . The high-offset belt tensioner of claim 1 , further comprises a bushing seated between the pivot tube and an interior surface of the arm arbor.
5 . The high-off-set belt tensioner of claim 1 , wherein the base comprises an arcuate tab engaged with an arcuate track in the pivot tube-receiving body of the arm, wherein the arcuate track limits the degrees of rotation of the arm about the first axis of rotation.
6 . The high-offset belt tensioner of claim 1 , wherein the torsion spring is an exposed torsion spring.
7 . The high-offset belt tensioner of claim 1 , wherein the base includes a spring abutment feature offset from the pivot tube against which the first spring end is operatively seated.
8 . The high-offset belt tensioner of claim 7 , wherein the spring abutment feature protrudes from an upper surface of the base in parallel arrangement with the pivot tube.
9 . The high-offset belt tensioner of claim 7 , wherein the base comprises a locating pin extending from a mounting surface of the base at a positioned opposite the spring abutment feature.
10 . The high-offset belt tensioner of claim 7 , wherein the torsion spring is an exposed torsion spring.
11 . The high-offset belt tensioner of claim 10 , wherein the first spring end of the torsion spring protrudes radially outward and bends around the spring abutment feature.
12 . The high-offset belt tensioner of claim 10 , wherein the base defines a spring cradle configured to receive a first coil of the torsion spring.
13 . The high-offset belt tensioner of claim 1 , wherein the pivot tube has an open free end and a generally closed opposing end, wherein the generally closed opposing end defines a bore configured to receive a mounting bolt.
14 . The high-offset belt tensioner of claim 13 , wherein the pivot tube has an open free end and a generally closed opposing end, wherein the generally closed opposing end defines a bore configured to receive a mounting bolt.
15 . The high-offset belt tensioner of claim 14 , wherein the bore has an axial flange extending into the pivot tube toward the free end thereof.
16 . The high-offset belt tensioner of claim 14 , wherein the base comprises an annular flange protruding axially upward in surrounding relationship to the pivot tube, wherein the annular flange has an inner diameter (ID) that is greater than an outer diameter (OD) of the pivot tube, thereby defining a gap therebetween configured to receive a bottom end 137 of the arm arbor 105 .
17 . The high-offset belt tensioner of claim 14 , wherein the free end of the pivot tube terminates with a splined or fluted exterior surface configured to receive a fastener.
18 . The high-offset belt tensioner of claim 1 , wherein the pulley pivot tube has a spring tang registration feature therein proximate a bottom bore thereof.