Control for fluid coupling

A fluid coupling comprising:

• a first rotatable member defining a housing rotatable about an axis;
• a second member disposed in the interior of said housing and rotatable about said axis;
• a working chamber defined by said members and containing an inventory of fluid for transmitting torque from one of said members to the other of said members via said fluid in response to relative rotation between said members;
• control means including moveable means biased toward a first position and moveable toward a second position in opposition to said biasing force in response to the rotational speed of said housing and operative to vary the torque transmitted by said fluid in proportion to the position of said moveable means between said first and second positions;
• and
• temperature sensing means for varying said biasing force in response to sensed temperature changes.

An improved control for varying the output speed of a fluid coupling of the type wherein an impeller member and a turbine member, which each include pockets formed by blade sets, define a toroidal chamber containing a fluid for transmitting torque from said impeller to said turbine in response to acceleration of the fluid in said impeller pockets and circulation to the turbine pockets, and whereby an increase in the rotational speed of the impeller relative to the turbine increases the fluid circulation and torque, said improvement comprising:

• means for stagnating fluid circulating in one of said pockets, thereby raising the static pressure of the stagnated fluid relative to the static pressure of the circulating fluid;
• and
• control means for varying said torque and fluid circulation independent of the rotational speed between said impeller member and turbine member, said control including
• 1. sensing means responsive to an operating condition of said coupling, and
• 2. valving means including a valving member moveable between first and second positions in response to sensed changes in said operating condition for controlling flow of said stagnated fluid from said one pocket, whereby said torque and fluid circulation in said chamber is controlled independent of the relative rotational speed between said impeller and turbine members.

An improved control for varying the output speed of a fluid coupling of the type wherein an impeller member and a turbine member, which each include pockets formed by blade sets, define a toroidal chamber containing a fluid for transmitting torque from said impeller to said turbine in response to acceleration of the fluid in said impeller pockets and circulation to the turbine pockets, and whereby an increase in the rotational speed of the impeller relative to the turbine increases the fluid circulation and torque, said improvement comprising:

• means for stagnating fluid circulating in one of said pockets, thereby raising the static pressure of the stagnated fluid relative to the static pressure of the circulating fluid;
• a second chamber defined by said turbine member;
• first passage means for communicating fluid flow from said one pocket to said second chamber;
• second passage means for communicating fluid flow from said second chamber to said toroidal chamber;
• valving means moveable between first and second positions and operative when in said first position to block fluid flow in said first passage and and allow fluid flow in said second passage, and operative when in said second position to allow fluid flow in said first passage and block fluid flow in said second passage;
• and
• sensing means responsive to an operating condition of said coupling for moving said valving means between said first and second positions in response to sensed changes in said operating condition.