worm gear axial clutch mechanism

Abstract

This invention provides an axial clutch mechanism for a worm gear, comprising a housing, a worm gear, a worm, two support units, two fasteners, and two preload elements. The worm is located on the outer periphery of the worm gear and has a meshing section, two non-meshing sections located axially outside the meshing section, and two mating sections located axially outside the two non-meshing sections. The two support units are respectively disposed on the two axial sides of the worm and form a sliding fit with the two mating sections. The two fasteners are respectively disposed at the two axial ends of the worm. The two preload elements are respectively disposed on the two mating sections and apply preload to the worm in opposite directions along its axial direction, thereby maintaining engagement between the meshing section and the worm gear. When the load force generated by one of the external loads on the worm gear is greater than the preload applied by one of the preload elements, the worm moves axially, causing the meshing section to move away from the worm gear and causing one of the non-meshing sections to move to a position corresponding to the worm gear, so that the worm and the worm gear are disengaged, thereby reducing the risk of structural damage.

Claims

1. A worm gear axial engagement / disengagement mechanism, comprising: a housing; a worm gear rotatably disposed within the housing; a worm located on the outer periphery of the worm gear and extending along a tangential direction of the outer periphery of the worm gear, the worm having a meshing section, two non-meshing sections located on the two axially outer sides of the meshing section, and two mating sections located on the two axially outer sides of the two non-meshing sections; two support units respectively disposed on the two axial sides of the worm and forming a sliding fit with the two mating sections to support the worm's rotation within the housing and allow the worm to move axially relative to the two support units; two fasteners respectively disposed on the two axial ends of the worm; and two preload elements respectively disposed on the two mating sections of the worm and applying preload directly or indirectly to the worm in opposite directions along the axial direction of the worm to maintain the worm in a meshing position and to keep the meshing section meshing with the teeth of the worm gear; wherein... When an external load is applied to the worm gear, the external load is transmitted to the worm through the meshing of the teeth of the worm gear and the meshing section, causing the worm to be subjected to a load force acting along its axial direction. When the load force is greater than the preload applied by one of the two preload elements, the worm is pushed by the load force and moves from the meshing position to a disengaged position along the direction of the load force. The two meshing sections slide axially relative to the two support units, causing the meshing section to move away from the position corresponding to the worm gear, and causing the non-meshing section located in the meshing section in the direction of the load force to move to the position corresponding to the worm gear, so that the worm and the worm gear disengage.

2. The worm gear axial clutch mechanism as described in claim 1, wherein, Each of the non-engaging segments has a smooth outer peripheral surface.

3. The worm gear axial clutch mechanism as described in claim 1, wherein, Each of the preload elements is either an elastic preload element or a magnetic preload element. The elastic preload element applies the preload force to the worm gear by means of elastic restoring force, while the magnetic preload element applies the preload force to the worm gear by means of magnetic attraction or magnetic repulsion force.

4. The worm gear axial clutch mechanism as described in claim 3, wherein, Both preload elements are elastic preload elements. Each elastic preload element is sleeved on the outer periphery of a corresponding mating section and disposed between a corresponding support unit and a fastener. One end of each elastic preload element directly or indirectly abuts against the corresponding support unit, and the other end abuts against the corresponding fastener, and is compressed along the axial direction of the worm by the fastener.

5. The worm gear axial clutch mechanism as described in claim 4, wherein, Each of these elastic preload elements is a compression spring, a polyurethane rubber, or an elastomer.

6. The worm gear axial clutch mechanism as described in claim 5, wherein, The worm has a threaded section at each of its two axial ends, and each fastener is a fastening nut screwed into the corresponding threaded section.

7. The worm gear axial clutch mechanism as described in claim 6, wherein, The position of each fastening nut relative to the corresponding threaded section can be adjusted to change the initial compression of the corresponding elastic preload element and adjust the preload applied to the worm by the elastic preload element.

8. The worm gear axial clutch mechanism as described in claim 1, wherein, One of the two support units includes a first support bearing, which is fixed relative to the housing. One of the two mating sections is cylindrical and passes through the first support bearing, so that the first support bearing provides radial support to the worm and allows the first mating section to rotate relative to the first support bearing and slide along the axial direction of the worm.

9. The worm gear axial clutch mechanism as described in claim 8, wherein, The second support unit of the two support units includes a driven gear, a second support bearing, and a third support bearing. The driven gear has a support shaft portion and a non-circular inner hole that extends axially along the support shaft portion. The second support bearing and the third support bearing are fixed relative to the housing and together support the support shaft portion, so that the driven gear can rotate relative to the housing. The second mating section of the two mating sections has a non-circular outer surface that passes through the non-circular inner hole. The non-circular inner hole and the non-circular outer surface engage with each other, so that the driven gear drives the worm to rotate and allows the second mating section to slide relative to the driven gear along the axial direction of the worm.

10. The worm gear axial clutch mechanism as described in claim 9, wherein, The non-circular inner hole is a polygonal inner hole, and the non-circular outer surface is a polygonal outer surface.

11. The worm gear axial clutch mechanism as described in claim 9 further includes a drive motor and a drive gear, the drive gear being connected to one output end of the drive motor and meshing with the driven gear, so that the drive motor drives the worm to rotate via the drive gear and the driven gear.

Images