The invention relates to a downhole tool for use in a petroleum well. The downhole tool (100) comprises a first part (110) comprising a driving unit (8), and second part (120) comprising a driven unit (9), wherein the drive unit (8) is configured for driving the driven unit (9). The downhole tool (100) comprises a coupling unit (1) having an input side (S1) coupled with the driving unit (8) and an output side (S2) coupled with the driven unit (9), wherein the driving unit (8) is configured for driving the driving unit (9) via the coupling unit (1) comprising a torque limiting coupling having a first operational mode, the coupling unit (1) transfers all torque from the input side (S1) to the output side (S2), the coupling unit (1) further having a second operational mode, wherein the coupling unit (1) slips such that less torque is transferred form the input side (S1) to the output side (S2), wherein the second operational mode is automatically activated when the torque load on the input side exceeds a predefined level, and wherein the first operational mode is automatically activated when the torque load on the input side reduces to a level below a further predefined level. The coupling unit (1) comprises a displacement pump (2), wherein the displacement pump (2) is activated by opening of a pressure-limitation valve (4), for facilitating slipping of the coupling unit (1) when the coupling unit (1) is switching to the second operational mode, and wherein the displacement pump (2) is deactivated by closing of the pressure-limitation valve (4), for locking the coupling unit (1) when the coupling unit (1) is switching to the first operational mode.

A working machine is disclosed. A boom supports an arm. An upper revolving body supports the boom. A lower traveling body mounts the upper revolving body in a rotatable state. A hydraulic actuator drives a hydraulic oil while relieving the hydraulic oil. A first pump supplies the hydraulic oil to the hydraulic actuator. A pump state detector detects load of the first pump. A controller reduces a flow rate of the hydraulic oil from the first pump to the hydraulic actuator when the pump state detector detects a predetermined state.

A working machine is disclosed. A boom supports an arm. An upper revolving body supports the boom. A lower traveling body mounts the upper revolving body in a rotatable state. A hydraulic actuator drives a hydraulic oil while relieving the hydraulic oil. A first pump supplies the hydraulic oil to the hydraulic actuator. A pump state detector detects load of the first pump. A controller reduces a flow rate of the hydraulic oil from the first pump to the hydraulic actuator when the pump state detector detects a predetermined state.

The invention relates to a downhole tool for use in a petroleum well. The downhole tool (100) comprises a first part (110) comprising a driving unit (8), and second part (120) comprising a driven unit (9), wherein the drive unit (8) is configured for driving the driven unit (9). The downhole tool (100) comprises a coupling unit (1) having an input side (S1) coupled with the driving unit (8) and an output side (S2) coupled with the driven unit (9), wherein the driving unit (8) is configured for driving the driving unit (9) via the coupling unit (1) comprising a torque limiting coupling having a first operational mode, the coupling unit (1) transfers all torque from the input side (S1) to the output side (S2), the coupling unit (1) further having a second operational mode, wherein the coupling unit (1) slips such that less torque is transferred form the input side (S1) to the output side (S2), wherein the second operational mode is automatically activated when the torque load on the input side exceeds a predefined level, and wherein the first operational mode is automatically activated when the torque load on the input side reduces to a level below a further predefined level. The coupling unit (1) comprises a displacement pump (2), wherein the displacement pump (2) is activated by opening of a pressure-limitation valve (4), for facilitating slipping of the coupling unit (1) when the coupling unit (1) is switching to the second operational mode, and wherein the displacement pump (2) is deactivated by closing of the pressure-limitation valve (4), for locking the coupling unit (1) when the coupling unit (1) is switching to the first operational mode.

The invention relates to a downhole tool for use in a petroleum well. The downhole tool (100) comprises a first part (110) comprising a driving unit (8), and second part (120) comprising a driven unit (9), wherein the drive unit (8) is configured for driving the driven unit (9). The downhole tool (100) comprises a coupling unit (1) having an input side (S1) coupled with the driving unit (8) and an output side (S2) coupled with the driven unit (9), wherein the driving unit (8) is configured for driving the driving unit (9) via the coupling unit (1) comprising a torque limiting coupling having a first operational mode, the coupling unit (1) transfers all torque from the input side (S1) to the output side (S2), the coupling unit (1) further having a second operational mode, wherein the coupling unit (1) slips such that less torque is transferred form the input side (S1) to the output side (S2), wherein the second operational mode is automatically activated when the torque load on the input side exceeds a predefined level, and wherein the first operational mode is automatically activated when the torque load on the input side reduces to a level below a further predefined level. The coupling unit (1) comprises a displacement pump (2), wherein the displacement pump (2) is activated by opening of a pressure-limitation valve (4), for facilitating slipping of the coupling unit (1) when the coupling unit (1) is switching to the second operational mode, and wherein the displacement pump (2) is deactivated by closing of the pressure-limitation valve (4), for locking the coupling unit (1) when the coupling unit (1) is switching to the first operational mode.

A method and system are provided for controlling the operating temperature of a torque converter during torque converter stall conditions. The torque converter has a pump rotatably driven by an internal combustion engine and a rotatable turbine fluidly coupled to the pump. The system first determines whether the torque converter is currently in a torque converter stall condition, and, if so, determines a slip speed as a difference in rotational speeds between the pump and the turbine, determines an engine output torque limit as a function of the slip speed and a desired slip speed, and controls the operating temperature of the torque converter by limiting output torque produced by the engine based on the engine output torque limit.

A method and system are provided for controlling the operating temperature of a torque converter during torque converter stall conditions. The torque converter has a pump rotatably driven by an internal combustion engine and a rotatable turbine fluidly coupled to the pump. The system first determines whether the torque converter is currently in a torque converter stall condition, and, if so, determines a slip speed as a difference in rotational speeds between the pump and the turbine, determines an engine output torque limit as a function of the slip speed and a desired slip speed, and controls the operating temperature of the torque converter by limiting output torque produced by the engine based on the engine output torque limit.

This invention refers to a hydraulic bearing clutch which is placed between the engine and the gear box, being suitable for any type of gear box. The hydraulic bearing clutch, according to this invention includes: a metal disc (1) coupled with an engine flywheel (2), a PTO shaft (3) attached to the metal disc (1) and tied in with a rotor (8) of the hydraulic pump (4) and a pressure chamber (7) mounted on the PTO shaft (3). Inside the hydraulic pump (4) there is a ball drum (9) tied in with the rotor (8) of the pump and in gear, through blocking, with the stator (15) of the pump. The stator is tied in with the primary shaft (6) on which are mounted a low pressure chamber (33) and a high pressure chamber (28). The high pressure chamber (28) is connected to a pressure regulator (38) and, through a solenoid valve (37), to the pressure chamber (7) on the PTO shaft (3). The pump rotor (8) has provided some radial rectangular seats (29) into which slide some metal blades (14), connected with an axial groove (11) and a radial groove (10) which correspond to the pressure chamber (7) on the PTO shaft (3). The axial groove (11) corresponds to a circular groove (17) and to the radial grooves (18) on the drum (9) and some balls (20) press on a circular groove (21) with bulges on the stator (15). The stator (15) is provided with admission ports (23), corresponding to the cross grooves (25) and the radial grooves (26), but also to the axial grooves (27) on the primary shaft (6). These grooves also make the connection with the high pressure chamber (28) and the low pressure chamber (33).