Rotary clutch assembly with actuator having threadingly engaged two-component armature

Patent metadata

Field	Value
Publication number	US-11149798-B2
Application number	US-201816632451-A
Country	US
Kind code	B2
Filing date	Jul 20, 2018
Priority date	Jul 20, 2017
Publication date	Oct 19, 2021
Grant date	Oct 19, 2021

Abstract

A rotary clutch uses a wrap spring clutch. An actuator generates a drag force to control the wrap spring clutch to engage or disengage the clutch. The actuator includes an electromagnet, a two-component armature and an axial return spring. The two-component armature includes first and second components threadingly connected one another for relative axial translation as they rotate relative to one another, and an angular position biasing member connecting them. The second component translates axially under magnetic force from the electromagnet, and when stopped by the electromagnet the first armature component translates axially due to their threaded connection. Due to the previous axial movement of the floating component the translation of the first armature component occurs in conditions where the air gap and reluctance of a magnetic circuit is reduced compared to the prior art, and thus the overall strength of the applied magnetic field can be comparatively reduced.

First claim

The invention claimed is:

1. A rotary clutch assembly, comprising:
a first rotary clutch portion that is disposed about a rotary axis and adapted to receive a rotary input;
a second rotary clutch portion that is disposed about the rotary axis and adapted to be coupled to a rotary output;
at least one of the first and second rotary clutch portions defining a clutch surface;
a wrap spring clutch having a power transfer end, a control end and a plurality of helical coils between the power transfer end and the control end, the plurality of helical coils engaging the clutch surface, the wrap spring clutch being configured to transmit or interrupt flow of rotary power between the first rotary clutch portion and the second rotary clutch portion depending on a drag force applied to the control end of the wrap spring clutch; and
an actuator that is selectively operable for generating said drag force, the actuator comprising an electromagnet, a two-component armature and an axial return spring,
wherein the two-component armature comprises a first armature component, a second armature component threadingly connected to the first armature component whereby the first and second armature components are capable of relative axial translation as the first and second armature components rotate relative to one another, and an angular position biasing member connecting the first and second armature components,
wherein the axial return spring is connected to the first armature component, and
wherein the second armature component translates axially under magnetic force applied by the electromagnet and is stopped thereby, and the first armature component translates axially due to the threaded connection between the first and second armature components.

2. A rotary clutch assembly according to claim 1 , wherein the angular position biasing member biases the first and second armature components towards an axially extensible condition.

3. A rotary clutch assembly according to claim 1 , wherein the first armature component and the second armature component have a range of relative angular motion therebetween less than 360 degrees.

4. A rotary clutch assembly according to claim 1 , wherein one of the first and second armature components includes a channel and the other of the first and second armature components includes a projection constrained by the channel, wherein the channel and projection enable the first and second armature components to translate axially relative to one another as the first and second armature components rotate relative to one another.

5. A rotary clutch assembly according to claim 4 , wherein the channel has a wide cross-sectional area and a narrow cross-sectional area, and the angular position biasing member biases the armature component having the projection to a position where the projection is disposed in the wide cross-sectional area.

6. A rotary clutch assembly according to claim 1 , wherein the second armature component is positionable to a first angular position relative to the first armature component where the second armature component has axial play relative to the first armature component, and wherein the second armature component is positionable to a second angular position relative to the first armature component where the first armature component has substantially no axial play relative to the first armature component, the angular position biasing member biasing the second armature component to the first angular position.

7. A rotary clutch assembly, comprising:
a first rotary clutch portion that is disposed about a rotary axis and adapted to receive a rotary input;
a second rotary clutch portion that is disposed about the rotary axis and adapted to be coupled to a rotary output;
at least one of the first and second rotary clutch portions defining a clutch surface;
a wrap spring clutch having a power transfer end, a control end and a plurality of helical coils between the power transfer end and the control end, the plurality of helical coils engaging the clutch surface, the wrap spring clutch being configured to transmit or interrupt flow of rotary power between the first rotary clutch portion and the second rotary clutch portion depending on a drag force applied to the control end of the wrap spring clutch; and
an actuator that is selectively operable for generating said drag force, the actuator comprising an electromagnet, a two-component armature and an axial return spring;
wherein the two-component armature comprises a holding component, a floating component entrained with the holding component, and an angular position biasing member connecting the floating and holding components;
wherein the floating component is positionable to a first angular position relative to the holding component where the floating component has axial play relative to the holding component and wherein the floating component is positionable to a second angular position relative to the holding component where the floating component has substantially no axial play relative to the holding component;
wherein the angular position biasing member biasing the floating component to the first angular position;
wherein the axial return spring is connected to the holding component;
wherein, in operation, the floating component translates axially under magnetic force applied by the electromagnet without having to overcome the bias of the axial return spring to thereby stop the floating component, whereby the holding component moves to the second angular position and translates axially due to mechanical linkage between the holding and floating components, overcoming the bias of the axial return spring.

Assignees

• Litens Automotive Inc

Inventors

• Yazigi Bashar

Classifications

• F16D13/08 Primary

  with a helical band or equivalent member, which may be built up from linked parts, with more than one turn embracing a drum or the like, with or without an additional clutch actuating the end of the band (F16D13/02 takes precedence; {similar slip couplings F16D7/022; similar clutches electromagnetically actuated F16D27/025, F16D27/105} ; similar free-wheel clutches F16D41/20; similar brakes F16D49/02) · CPC title

• F16D27/105

  with a helical band or equivalent member co-operating with a cylindrical coupling surface · CPC title