Belt tensioning device

Patent metadata

Field	Value
Publication number	US-10400871-B2
Application number	US-201615262101-A
Country	US
Kind code	B2
Filing date	Sep 12, 2016
Priority date	Sep 17, 2015
Publication date	Sep 3, 2019
Grant date	Sep 3, 2019

Abstract

A belt tensioning device comprises a base member; at least one tensioning arm which, relative to the base member, is pivotably supported around a pivot axis; a tensioning roller for tensioning the belt; a spring for resiliently supporting the tensioning arm; and a connecting assembly for connecting the tensioning arm to the base member, wherein the connecting assembly comprises at least two base member connecting portions and at least two tensioning arm connecting portions which are connected to one another by an insertion and rotational movement; wherein, between a first base member connecting portion and a first tensioning arm connecting portion a first contact surface region is formed which is greater than a second contact surface region which is formed between a second base member connecting portion and a second tensioning arm connecting portion.

First claim

The invention claimed is:

1. A belt tensioning device for a belt drive, comprising:
a base member which is attachable to an assembly having a drive shaft and a belt pulley;
at least one tensioning arm which is pivotably supported relative to the base member around a pivot axis;
a tensioning roller for tensioning the belt, which tensioning roller is connected to the tensioning arm so as to be rotatable around a rotational axis;
a spring by which the tensioning arm is resiliently supported in circumferential direction; and
a connecting assembly for connecting the tensioning arm to the base member;
wherein the connecting assembly comprises at least two circumferentially extending base member connecting portions and at least two circumferentially extending tensioning arm connecting portions which are connected to one another by an insertion and rotation movement; and
further wherein the tensioning arm comprises an opening that is configured such that at least one of the drive shaft and the belt pulley of the assembly are extendable into said opening in a mounted condition, wherein a wall of the tensioning arm that surrounds the opening is provided with circumferentially distributed ribs, wherein the ribs comprise a greater thickness in a foot portion than in a head portion;
wherein in the mounted condition a first contact surface region formed between a first base member connecting portion and a first tensioning arm connecting portion is at least 10% greater than a second contact surface region formed between a second base member connecting portion and a second tensioning arm connecting portion.

2. The belt tensioning device according to claim 1 ,
wherein between two circumferentially adjoining base member connecting portions a recess is formed;
the at least two circumferentially extending tensioning arm connecting portions are provided in the form of radial projections; and
the tensioning arm is configured to be axially introduced into the base member in a rotational position in which the radial projections of the tensioning arm are arranged in the circumferential region of the recesses of the base member.

3. The belt tensioning device according to claim 1 , wherein the base member connecting portions and the tensioning arm connecting portions are designed such that the tensioning arm and the base member can be inserted into one another in exactly one predetermined rotational position.

4. The belt tensioning position according to claim 1 , wherein, in the foot portion, the ribs comprise a variable width along a height, wherein the height of the foot portion with a variable thickness amounts to at least 10% of the total height of the rib.

5. The belt tensioning device according to claim 1 ,
wherein, in the head portion, the ribs comprise a constant thickness along a height, and
wherein the height of the head portion with a constant thickness amounts to at least 50% of the total height of the rib.

6. The belt tensioning device according to claim 1 , wherein a smallest distance formed between two adjoining ribs in the head portion is greater than a smallest distance formed between two adjoining ribs in the foot portion.

7. The belt tensioning device according to claim 1 , wherein, at the wall of the tensioning arm, the ribs extend around a circumferential portion of at least 60 around the pivot axis.

8. The belt tensioning device according to claim 1 ,
wherein a bearing arrangement is provided between the base member and the tensioning arm for rotatably supporting the tensioning arm relative to the base member around the pivot axis;
wherein the bearing arrangement comprises at least one bearing element associated with the base member and at least one bearing element associated with the tensioning arm;
wherein one of the bearing elements is produced from a metal-based material and the other one of the bearing elements is produced from a plastic material.

9. The belt tensioning device according to claim 1 , wherein the base member and the tensioning arm are produced from different materials, wherein at least one of the base member and the tensioning arm is at least partially produced from plastics.

10. The belt tensioning device according to claim 9 , wherein the at least one of the base member and the tensioning arm is produced from glass fibre reinforced plastics.

11. The belt tensioning device according to claim 1 , wherein the bearing element associated with the base member is produced from a bearing material which comprises a higher thermal conductivity than the basic material of the base member.

12. The belt tensioning device according to claim 1 ,
wherein the spring is provided in the form of a helical spring whose spring axis, in the built-in condition, extends at least substantially parallel to the pivot axis, wherein the helical spring comprises at most three full windings;
wherein the ratio of nominal diameter of the helical spring relative to the axial length of the helical spring is greater than 3.0 in the built-in condition.

Assignees

• Muhr & Bender Kg

Inventors

• Buchen Thomas
• Diblik Jan
• Vollmer Frederik

Classifications

• F16H7/1218 Primary

  of the dry friction type · CPC title

• F16H2007/081

  Torsion springs · CPC title

• F16H7/1281 Primary

  where the axis of the pulley moves along a substantially circular path · CPC title

• F16H2007/0893

  Circular path · CPC title

• F16H2007/0865

  Pulleys · CPC title