A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

A clutch unit includes a lever-side clutch part to control transmission and interruption of rotational torque input through a lever operation and a brake-side clutch part to transmit the rotational torque from the lever-side clutch part to the output side and interrupt rotational torque reversely input from the output side. The brake-side clutch part includes an outer ring constrained in rotation, an output shaft to output the rotation, cylindrical rollers to control interruption of the rotational torque reversely input from the output shaft and transmission of the rotational torque input from the lever-side clutch part through engagement and disengagement between the outer ring and the output shaft, a friction ring to apply a rotational resistance to the output shaft, and a variable part to change the rotational resistance applied to the output shaft between the transmission and the interruption of the rotational torque.

Methods and apparatus for predicting clutch local peak temperatures in real time and controlling engagement of a friction clutch are disclosed. The clutch local peak temperature prediction can take into account machine operating parameters such as clutch control current, clutch shaft speed and clutch load to determine clutch local peak temperatures at hot spots within the friction clutch. A thermal-mechanical finite element analysis model may be developed for the friction clutch and used to generate a surrogate model of the friction clutch that can be used by an electronic control module of the machine to predict the local peak temperature of the friction clutch in real time and control engagement and disengagement of the friction clutch to maintain the local peak temperature below a critical peak temperature above which damage to the components of the friction clutch may occur.

Methods and apparatus for predicting clutch local peak temperatures in real time and controlling engagement of a friction clutch are disclosed. The clutch local peak temperature prediction can take into account machine operating parameters such as clutch control current, clutch shaft speed and clutch load to determine clutch local peak temperatures at hot spots within the friction clutch. A thermal-mechanical finite element analysis model may be developed for the friction clutch and used to generate a surrogate model of the friction clutch that can be used by an electronic control module of the machine to predict the local peak temperature of the friction clutch in real time and control engagement and disengagement of the friction clutch to maintain the local peak temperature below a critical peak temperature above which damage to the components of the friction clutch may occur.

A clutched driven device (10) having a clutch assembly (16) with a first rotary clutch portion (50), a second rotary clutch portion (52), a bearing (54), a wrap spring (56) and an actuator (60). The first rotary clutch portion has an interior clutch surface (76). The first and second rotary clutch portions are rotatably disposed about a rotary axis (70) of the clutched driven device. The bearing is received between the first and second rotary clutch portions and supports the first rotary clutch portion for rotation on the second rotary clutch portion. The wrap spring is disposed radially inwardly of the bearing and has a plurality of helical coils (114) that are received against the interior clutch surface. The actuator is configured to selectively initiate coiling of the wrap spring to cause the helical coils of the wrap spring to disengage the interior clutch surface to a predetermined extent.

A clutched driven device (10) having a clutch assembly (16) with a first rotary clutch portion (50), a second rotary clutch portion (52), a bearing (54), a wrap spring (56) and an actuator (60). The first rotary clutch portion has an interior clutch surface (76). The first and second rotary clutch portions are rotatably disposed about a rotary axis (70) of the clutched driven device. The bearing is received between the first and second rotary clutch portions and supports the first rotary clutch portion for rotation on the second rotary clutch portion. The wrap spring is disposed radially inwardly of the bearing and has a plurality of helical coils (114) that are received against the interior clutch surface. The actuator is configured to selectively initiate coiling of the wrap spring to cause the helical coils of the wrap spring to disengage the interior clutch surface to a predetermined extent.

A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).

A power transmitting apparatus has a clutch member and a pressure member. The cam surfaces of the pressure-contact assist cam face each other. The cam surfaces of the back torque limiter cam face each other. A receiving portion for a clutch spring (10) on the pressure member (5) side has a receiving member (11) separate from the pressure member (5). A first cam surface (C1) and a second cam surface (C2), constituting the back torque limiter cam, are, respectively, formed on the receiving member (11) and the clutch member (4). A third cam surface (C3) and a fourth cam surface (C4), constituting the pressure-contact assist cam, are, respectively, formed on the pressure member (5) and the clutch member (4).