Chain saw

1 . A chain saw, comprising:

a housing extending substantially along a front and rear direction and formed with an accommodation space;

an electric motor at least partially disposed in the accommodation space;

a transmission system connected to the electric motor and capable of outputting a driving force;

a control system comprising a circuit board assembly, the circuit board assembly extending in a plane; and

a power supply assembly disposed on a rear side of the housing and used for powering the electric motor;

wherein the circuit board assembly obliquely intersects with a first straight line extending along the front and rear direction; in a direction of a second straight line perpendicular to a direction of the first straight line and extending along an up and down direction, the electric motor has a first projection surface perpendicular to the direction of the second straight line and the circuit board assembly has a second projection surface perpendicular to the direction of the second straight line;

the first projection surface of the electric motor at least partially overlaps the second projection surface of the circuit board assembly;

the electric motor has a third projection surface in an upper and lower plane perpendicular to the direction of the first straight line and the circuit board assembly has a fourth projection surface in the upper and lower plane perpendicular to the direction of the first straight line;

the third projection surface of the electric motor at least partially overlaps the fourth projection surface of the circuit board assembly;

the electric motor comprises an electric motor shaft; the transmission system comprises an output shaft, a first gear connected to the output shaft, and a second gear connected to the electric motor shaft; a diameter of the second gear is smaller than a diameter of the first gear; the circuit board assembly comprises an upper end and an lower end; and

the upper end is arranged on an upper side of the first gear and the lower end is arranged on an upper side of the second gear so that the circuit board assembly extends from the upper side of the first gear to the upper side of the second gear at an angle relative to the first straight line.

2 . The chain saw according to claim 1 , wherein in the direction of the second straight line, the transmission system has a fifth projection surface perpendicular to the direction of the second straight line; and the fifth projection surface of the transmission system at least partially overlaps the second projection surface of the circuit board assembly.

3 . The chain saw according to claim 1 , wherein the electric motor is an external rotor electric motor, and a ratio of a mass of the electric motor to a mass of the chain saw is greater than or equal to 0.07 and less than or equal to 0.4.

4 . The chain saw according to claim 1 , further comprising an oil pumping system which comprises an oil can, wherein the housing is formed with an opening communicating with an outside along both the front and rear direction and a left and right direction, and the oil can is at least partially disposed in the accommodation space and seals at least part of the opening.

5 . The chain saw according to claim 4 , wherein the oil pumping system, the transmission system, the electric motor, and the power supply assembly are sequentially arranged along the front and rear direction.

6 . The chain saw according to claim 1 , wherein the housing further comprises an air inlet and an air outlet, wherein when the chain saw is running, a heat dissipation air path flowing in from the air inlet and flowing out from the air outlet is capable of being formed, and the heat dissipation air path is capable of flowing through the transmission system and the control system simultaneously.

7 . The chain saw according to claim 6 , wherein the air outlet is configured to have a first blowing direction in which air is capable of being blown forward and a second blowing direction in which the air is capable of being blown backward.

8 . The chain saw according to claim 1 , further comprising a guide plate connected to the housing and a chain distributed around the guide plate;

wherein the output shaft is capable of driving the chain to rotate;

the chain saw further comprises a cover plate capable of sealing at least part of the guide plate and at least part of the chain, the cover plate and the housing are connected to each other and form a chip discharge space, and the output shaft is at least partially disposed in the chip discharge space; and

the electric motor shaft is disposed away from the chip discharge space.

9 . The chain saw according to claim 1 , wherein the transmission system comprises a gearbox distributed along the front and rear direction, and the electric motor and the output shaft of the transmission system are disposed on a same side of the gearbox.

10 . The chain saw according to claim 1 , wherein a length of the chain saw in the front and rear direction is less than or equal to 330 mm, and a width of the chain saw in a left and right direction is less than or equal to 150 mm.

11 . The chain saw according to claim 1 , wherein the housing further comprises a lower bottom surface substantially perpendicular to the up and down direction, the housing is recessed away from the lower bottom surface so that a hook is formed.

12 . The chain saw according to claim 1 , wherein a width of the chain saw in a left and right direction is less than or equal to 150 mm.

13 . The chain saw according to claim 1 , further comprising an oil can, wherein the oil can is exposed on front and left sides of the housing so that the oil can is observable in both the front and rear direction and a left and right direction.

14 . The chain saw according to claim 1 , wherein the housing is further formed with a hook, and the hook does not protrude from a lower bottom surface of the chain saw.

15 . The chain saw according to claim 1 , wherein the housing is formed with a coupling portion to which the power supply assembly is mounted, the housing is further formed with a guide slot guiding the power supply assembly to be mounted to the coupling portion, the guide slot extends along a left and right direction perpendicular to the front and rear direction, and the power supply assembly is mounted to the coupling portion.