Drive device and image forming apparatus incorporating the drive device

A drive device comprising:

• a drive source configured to exert a driving force;
• an input side rotary shaft rotatably disposed and configured to receive the driving force from the drive source;
• an output side rotary shaft rotatably disposed and configured to transmit the driving force to a driving target body configured to rotate in a forward direction or a reverse direction opposite to the forward direction;
• a first drive transmission route configured to transmit the driving force from the input side rotary shaft to the output side rotary shaft if the driving target body is rotated in the forward direction;
• and
• a second drive transmission route configured to transmit the driving force from the input side rotary shaft to the output side rotary shaft if the driving target body is rotated in the reverse direction, the second drive transmission route including an electromagnetic clutch configured to switch the second drive transmission route between a transmission state in which the driving force is transmitted and a non-transmission state in which transmission of the driving force is cut off, wherein
• the only clutch in the drive device is the electromagnetic clutch included in the second drive transmission route, and
• the first drive transmission route includes a torque limiter configured to,
• transmit the driving force via the first drive transmission route to the output side rotary shaft if the second drive transmission route is in the non-transmission state, and
• restrict the transmission of the driving force from the first drive transmission route to the output side rotary shaft if the second drive transmission route is in the transmission state.

A drive device comprising:

• a drive source configured to exert a driving force;
• an input side rotary shaft rotatably disposed and configured to receive the driving force from the drive source;
• an output side rotary shaft rotatably disposed and configured to transmit the
• driving force to a driving target body configured to rotate in a forward direction or a reverse direction opposite to the forward direction;
• a first drive transmission route configured to transmit the driving force from the
• input side rotary shaft to the output side rotary shaft if the driving target body is rotated in the forward direction;
• and
• a second drive transmission route configured to transmit the driving force from
• the input side rotary shaft to the output side rotary shaft if the driving target body is rotated in the reverse direction, the second drive transmission route including an electromagnetic clutch configured to switch the second drive transmission route between a transmission state in which the driving force is transmitted and a non-transmission state in which transmission of the driving force is cut off,
• wherein the first drive transmission route includes a torque limiter configured to, transmit the driving force via the first drive transmission route to the output side rotary shaft if the second drive transmission route is in the non-transmission state, and restrict the transmission of the driving force from the first drive transmission route to the output side rotary shaft if the second drive transmission route is in the transmission state, and
• wherein the torque limiter and the electromagnetic clutch work together to transmit the drive force to the output side rotary shaft through either the first transmission route or the second transmission route.