Drive mechanism and image forming apparatus

1. A drive mechanism for transmitting a drive force to drive a processing apparatus which carries out a prescribed process, comprising:

an output portion configured to output the drive force;

an electromagnetic clutch configured to control transmission of the drive force to the output portion; and

a case including a first storage section which defines a first storage room to store the output portion, and a second storage section which defines a second storage room to store the electromagnetic clutch, wherein

the second storage section includes a peripheral wall which projects outwards from the first storage section to surround the electromagnetic clutch, and a supporting wall which supports the electromagnetic clutch;

the peripheral wall includes an upper wall above the electromagnetic clutch and a lower wall below the electromagnetic clutch; and

an opening section is formed only in the upper wall.

2. The drive mechanism according to claim 1 , wherein

the electromagnetic clutch includes a coil to which electric current is supplied to electrically control the transmission of the drive force and a metallic shell which surrounds the coil; and

the opening section is formed above the shell.

3. An image forming apparatus for forming an image, comprising:

an image forming unit configured to form an image on a sheet;

a conveyance portion configured to convey the sheet to the image forming unit; and

a drive mechanism configured to transmit a drive force to the conveyance portion, wherein

the drive mechanism includes:

an output portion configured to output the drive force;

an electromagnetic clutch configured to control transmission of the drive force to the output portion; and

a case including a first storage section which defines a first storage room to store the output portion, and a second storage section which defines a second storage room to store the electromagnetic clutch;

the second storage section includes a peripheral wall which projects outwards from the first storage section to surround the electromagnetic clutch, and a supporting wall which supports the electromagnetic clutch;

the peripheral wall includes an upper wall above the electromagnetic clutch and a lower wall below the electromagnetic clutch; and

an opening section is formed in the upper wall.

4. The image forming apparatus according to claim 3 , wherein

the conveyance portion includes an feed timing adjustor which matches a conveyance timing of the sheet to the image forming unit with an image formation timing by the image forming unit;

the output portion includes a first output portion which outputs the drive force to the feed timing adjustor; and

the electromagnetic clutch includes a first electromagnetic clutch which controls the transmission of the drive force to the first output portion.

5. The image forming apparatus according to claim 4 , wherein

the conveyance portion includes a sheet feeder which feeds the sheet to the feed timing adjustor;

the output portion includes a second output portion which outputs the drive force to the sheet feeder; and

the electromagnetic clutch includes a second electromagnetic clutch which controls the transmission of the drive force to the second output portion.

6. The image forming apparatus according to claim 5 , further comprising:

a main housing in which a return path is formed to guide the sheet to the feed timing adjustor after image formation on the sheet by the image forming unit, wherein

the conveyance portion includes a conveyance portion which conveys the sheet along the return path;

the output portion includes a third output portion which outputs the drive force to the conveyance portion; and

the electromagnetic clutch includes a third electromagnetic clutch which controls the transmission of the drive force to the third output portion.

7. The drive mechanism according to claim 1 , wherein

the opening section opens upward.