A clutch system includes a rotary input member, a wrap spring clutch and a rotary output member. The wrap spring clutch has a first end, a second end, and a plurality of coils. The stiffness of the wrap spring clutch is selected such that, when transmitting less than a selected coil engagement torque, the clutch system transmits torque helically from the rotary input member, to the second end, helically through the wrap spring clutch to the first end, and into the rotary output member. When transmitting more than the selected coil engagement torque, the clutch system transmits torque in parallel from the rotary input member, to the second end, helically through the wrap spring clutch to the first end, and into the rotary output member, and from the rotary input member through the coil engagement surface, to the first end, and into the rotary output member.

An automotive air conditioning assembly including a scroll compressor and a wrap spring clutch. The wrap spring clutch enables the use of a comparatively smaller pulley (a diameter of at most 85 mm) which comparatively increases the compressor speed and hence cooling capacity at a given engine speed. The clutch requires low power (e.g. less than 5 Watts) for continuous operation.

A gear apparatus for controlling movement of an output by an input coupled to a power source. The apparatus an input member coupled to the input, an output member coupled to the output and the input member so that movement of the input member causes movement of the output, a selectably releasable member coupled to the input member and the output member, wherein the selectably releasable member remains in a fixed position while the input member and the output member move, and a releasable member brake mechanism coupled to the selectably releasable member, wherein the releasable member brake mechanism is arranged to prevent movement of the selectably releasable member when the input member and the output member move and to allow back driving of the selectably releasable member.

A gear apparatus for controlling movement of an output by an input coupled to a power source. The apparatus an input member coupled to the input, an output member coupled to the output and the input member so that movement of the input member causes movement of the output, a selectably releasable member coupled to the input member and the output member, wherein the selectably releasable member remains in a fixed position while the input member and the output member move, and a releasable member brake mechanism coupled to the selectably releasable member, wherein the releasable member brake mechanism is arranged to prevent movement of the selectably releasable member when the input member and the output member move and to allow back driving of the selectably releasable member.

A method for installing a wrap spring includes providing a first sleeve with a first longitudinal axis extending in an axial direction and a lateral surface, and the wrap spring designed to frictionally abut the lateral surface. The wrap spring includes a nominal diameter and a central axis. The method includes applying the wrap spring in a relaxed state to the lateral surface at an angle α between the central axis and the first longitudinal axis, elastically twisting the wrap spring to change the nominal diameter while the wrap spring contacts the lateral surface, reducing the angle α, threading the wrap spring onto the first sleeve, and relaxing the wrap spring to establish frictional contact with the lateral surface.

A variety of brake and/or clutch mechanisms, and improvements thereof, are provided having improved braking power, reduced size and weight, and other benefits. The braking mechanisms include a wrap spring clutch that is operable to mechanically couple a rotating member to a brake rotor that is in consistent contact with a brake pad. Actuation of the wrap spring clutch allows the wrap spring to engage with the rotating member, coupling the rotating member to the brake rotor thus braking the rotating member. The combination of the wrap spring clutch with the brake rotor and pad provides an overall braking mechanism that exhibits the decreased power cost, weight, size, and engagement time of the wrap spring clutch while having a braking power that can be moderated by specifying the area, engagement force, coefficient of friction, or other properties of the brake rotor and pad.

A variety of brake and/or clutch mechanisms, and improvements thereof, are provided having improved braking power, reduced size and weight, and other benefits. The braking mechanisms include a wrap spring clutch that is operable to mechanically couple a rotating member to a brake rotor that is in consistent contact with a brake pad. Actuation of the wrap spring clutch allows the wrap spring to engage with the rotating member, coupling the rotating member to the brake rotor thus braking the rotating member. The combination of the wrap spring clutch with the brake rotor and pad provides an overall braking mechanism that exhibits the decreased power cost, weight, size, and engagement time of the wrap spring clutch while having a braking power that can be moderated by specifying the area, engagement force, coefficient of friction, or other properties of the brake rotor and pad.

A shifting system includes an input member, a disconnect, an output member, and a shifting assembly to selectively rotationally couple the input member and the output member. The shifting assembly includes an input hub having a disconnectable component engageable with the disconnect and a clutch engagement component extending radially away from an axis. A plurality of clutch plates is coupled to the clutch engagement component and is moveable between engaged and disengaged positions. A biasing member is coupled to the clutch plates to bias the clutch plates toward the engaged position, and an apply plate is coupled to the biasing member. The apply plate is moveable between a first plate position where the clutch plates are in the engaged position, and a second plate position where the clutch plates are in the disengaged position. A clutch plate carrier is coupled to the clutch plates and to the output member.

A shifting system includes an input member, a disconnect, an output member, and a shifting assembly to selectively rotationally couple the input member and the output member. The shifting assembly includes an input hub having a disconnectable component engageable with the disconnect and a clutch engagement component extending radially away from an axis. A plurality of clutch plates is coupled to the clutch engagement component and is moveable between engaged and disengaged positions. A biasing member is coupled to the clutch plates to bias the clutch plates toward the engaged position, and an apply plate is coupled to the biasing member. The apply plate is moveable between a first plate position where the clutch plates are in the engaged position, and a second plate position where the clutch plates are in the disengaged position. A clutch plate carrier is coupled to the clutch plates and to the output member.

One aspect is a wrap spring clutch with a rotatable input and a spring having a first and a second end and having an equilibrium state and a flexed state, the spring engaged with the input through one of the first and second ends such that the spring rotates with the input and with an input torque transmitted exclusively through one of the first and second ends when the input rotates. A damper mechanism is engaged with one of the first and second ends such that the damper mechanism causes the spring to change from its equilibrium to its flexed state when the input transitions from stationary to rotational, and such that the damper mechanism allows the spring to change from its flexed to its equilibrium state when the input transitions from rotational to stationary. A rotatable output is positioned relative to the spring such that the output synchronously rotates with the input when the spring is in its flexed state and rotates independently of the input when the spring is in its equilibrium state.