Belt tensioning device

Patent metadata

Field	Value
Publication number	US-9638294-B2
Application number	US-201514677038-A
Country	US
Kind code	B2
Filing date	Apr 2, 2015
Priority date	Apr 8, 2014
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A belt tensioning device for a belt drive comprises a base member that is firmly connectable to a stationary component; at least one tensioning arm, which is pivotably supported relative to the base member around a pivot axis; a spring element, with which the tensioning arm is supported elastically in circumferential direction, wherein the ratio of the nominal diameter to the axial length of the spring element is larger than 3.0 in the mounted condition; and a tensioning roller for tensioning the belt, which is rotatably supported on the tensioning arm around an axis of rotation; wherein the base member and the tensioning arm are each at least partially made from plastic material.

First claim

The invention claimed is:

1. A belt tensioning device for a belt drive, comprising:
a base member that is connectable to a stationary component;
at least one tensioning arm pivotably supported relative to the base member around a pivot axis, wherein the tensioning arm has an opening which is configured such that at least one of a drive shaft and a belt pulley of an accessory are extendable into said opening in a mounted condition, wherein a wall of the tensioning arm encasing the opening comprises ribs that are circumferentially distributed;
a spring element that resiliently supports the tensioning arm in a circumferential direction, wherein the spring element has a nominal diameter and an axial length in a mounted condition, and wherein a ratio of the nominal diameter to the axial length of the spring element is larger than 3.0 in the mounted condition, and
a tensioning roller arranged to tension the belt, the tensioning roller being rotatably supported on the tensioning arm around an axis of rotation, wherein the base member and the tensioning arm are each at least partially made from a plastic material.

2. The belt tensioning device of claim 1 , further comprising a connection mechanism for connecting the tensioning arm to the base member, wherein the connection mechanism has at least one first connection element, which is associated to the base member, and at least one second connection element, which is associated to the tensioning arm, wherein the first connection element and the second connection element are configured to be connected to each other by an insertion and rotational movement.

3. The belt tensioning device of claim 2 , wherein the connection mechanism is formed such that the tensioning arm and the base member are insertable into one another only in exactly one predetermined rotational position.

4. The belt tensioning device of claim 1 , wherein the base member and the tensioning arm are manufactured from a glass fiber reinforced plastic material.

5. The belt tensioning device of claim 1 , wherein at least one of the base member and the tensioning arm has at least one reinforcing element made from a metal material, which is over-molded with a plastic material.

6. The belt tensioning device of claim 1 , further comprising a bearing arrangement 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 has at least one bearing element associated to the base member and at least one bearing element associated to the tensioning arm.

7. The belt tensioning device of claim 6 , wherein a plurality of bearing elements are provided at the base member and are arranged in segments along a circumference.

8. The belt tensioning device of claim 6 , wherein the at least one bearing element and the base member are integrally formed as a single unit.

9. The belt tensioning device of claim 6 , wherein the base member is made from a first plastic material and the at least one bearing element is made from a second plastic material, wherein the first and the second plastic material have different material characteristics.

10. The belt tensioning device of claim 6 , wherein the at least one bearing element of the tensioning arm is made from a metal material.

11. The belt tensioning device of claim 1 , wherein the ribs extend one of parallel, at an angle, or arched in relation to the pivot axis.

12. The belt tensioning device of claim 1 , wherein at least one damping element is provided made from a dampening material that differs from the plastic material of the base member and the tensioning arm.

13. The belt tensioning device of claim 1 , wherein the spring element is formed as a helical spring, wherein a spring axis of the helical spring extends at least substantially parallel to the pivot axis in the mounted condition, wherein the helical spring has a maximum of three complete turns.

14. The belt tensioning device of claim 1 , wherein the ratio of the nominal diameter of the spring element to the axial length of the spring element is larger than 5.0 in the mounted condition.

15. The belt tensioning device of claim 1 , wherein the ribs extend parallel in relation to the pivot axis.

16. A belt tensioning device for a belt drive, comprising:
a base member that is connectable to a stationary component;
at least one tensioning arm pivotably supported relative to the base member around a pivot axis;
a spring element that resiliently supports the tensioning arm in a circumferential direction, wherein the spring element has a nominal diameter and an axial length in a mounted condition, and wherein a ratio of the nominal diameter to the axial length of the spring element is larger than 3.0 in the mounted condition;
a tensioning roller arranged to tension the belt, the tensioning roller being rotatably supported on the tensioning arm around an axis of rotation, wherein the base member and the tensioning arm are each at least partially made from a plastic material; and
a connection mechanism for connecting the tensioning arm to the base member, wherein the connection mechanism has at least one first connection element, which is associated to the base member, and at least one second connection element, which is associated to the tensioning arm, wherein the first connection element and the second connection element are configured to be connected to each other by an insertion and rotational movement.

17. The belt tensioning device of claim 16 , wherein the connection mechanism is formed such that the tensioning arm and the base member are insertable into one another only in exactly one predetermined rotational position.

18. The belt tensioning device of claim 16 , wherein the base member and the tensioning arm are manufactured from a glass fiber reinforced plastic material.

19. A belt tensioning device for a belt drive, comprising:
a base member that is connectable to a stationary component;
at least one tensioning arm pivotably supported relative to the base member around a pivot axis;
a spring element that resiliently supports the tensioning arm in a circumferential direction, wherein the spring element has a nominal diameter and an axial length in a mounted condition, and wherein a ratio of the nominal diameter to the axial length of the spring element is larger than 3.0 in the mounted condition; and
a tensioning roller arranged to tension the belt, the tensioning roller being rotatably supported on the tensioning arm around an axis of rotation, wherein the base member and the tensioning arm are each at least partially made from a plastic material; and
a bearing arrangement 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 has at least one bearing element associated to the base member and at least one bearing element associated to the tensioning arm,
wherein the base member is made from a first plastic material and the at least one bearing element is made from a second plastic material, wherein the first and the second plastic material have different material characteristics.

Assignees

• Muhr & Bender Kg

Inventors

• Buchen Thomas
• Diblik Jan
• Vollmer Frederik

Classifications

• F16H2007/0865

  Pulleys · CPC title

• F16H7/1209

  with vibration damping means · CPC title

• F16H7/12 Primary

  of an idle pulley · 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