Driving tool

1 . A driving tool comprising:

a driver configured to move in a driving direction to drive a driving member;

a wheel configured to engage the driver, the wheel including a plurality of engagement portions;

an electric motor configured to rotate the wheel for moving the driver in a direction opposite to the driving direction via the plurality of engagement portions;

a holder attached to the wheel;

at least one grease reservoir formed in the holder; and

at least one grease flow passage configured to connect the at least one grease reservoir and at least one of the plurality of engagement portions, the at least one of the plurality of engagement portions engaging the driver at a standby position, wherein

the wheel includes supporting holes for inserting the plurality of engagement portions, and

the at least one grease flow passage includes a first grease flow passage having an extension groove arranged on an outer surface of the wheel facing the holder and configured to extend from one of the supporting holes.

2 . The driving tool according to claim 1 , wherein:

the extension groove extends in an arc-shape centered at a rotation center of the wheel; and

the first grease flow passage further includes a penetrating groove for penetrating the wheel from the extension groove along an inner circumferential surface of the one of the supporting hole.

3 . The driving tool according to claim 1 , wherein:

the at least one grease flow passage includes a second grease flow passage having a recess arranged on an outer surface of the wheel facing the holder and a first communicating hole connected to the recess, the first communicating hole being opened toward the at the least one of the plurality of engagement portions.

4 . The driving tool according to claim 3 , further comprising a cover between the wheel and the holder for covering the at least one grease reservoir,

wherein the cover includes a second communicating hole configured to be opened to the recess of the wheel, the second communicating hole being a part of the second grease flow passage for flowing grease to the recess.

5 . The driving tool according to claim 3 , wherein:

the wheel includes a front flange, a rear flange and a coupling member, the front flange and the rear flange being integrally connected to each other via the coupling member; and

the coupling member includes the first communicating hole.

6 . The driving tool according to claim 1 , wherein the at least one grease reservoir includes a tilting surface positioned at a circumferential end of the at least one grease reservoir so as to be tilted relatively to a depth direction of the at least one grease reservoir and extends along the at least one grease flow passage.

7 . The driving tool according to claim 1 , wherein the holder includes a magnet for detecting a rotation position of the wheel.

8 . The driving tool according to claim 1 , further comprising a cover between the wheel and the holder for covering the at least one grease reservoir,

wherein the cover includes at least one hole being a part of the grease flow passage for flowing grease to the at least one of the plurality of engagement portions.

9 . The driving tool according to claim 8 , wherein:

the cover includes a plurality of holes, the plurality of holes being arranged so as to be asymmetrically arranged with respect to a rotation center of the cover; and

the holder includes a cylindrical-shaped positioning protrusion positioned at a front surface of the holder and insertable to one of the plurality of holes.

10 . The driving tool according to claim 1 , further comprising a cover between the wheel and the holder for covering the at least one grease reservoir,

wherein the cover includes an opening hole configured to be opened to the extension groove of the wheel, the opening hole being a part of the first grease flow passage for flowing grease to the extension groove.

11 . The driving tool according to claim 10 , wherein:

the at least one grease flow passage includes a second grease flow passage having a recess arranged on an outer surface of the wheel facing the holder and a first communicating hole connected to the recess, the first communicating hole being opened toward the at the least one of the plurality of engagement portions, and

the cover includes a second communicating hole configured to be opened to the recess of the wheel, the second communicating hole being a part of the second grease flow passage for flowing the grease to the recess.

12 . The driving tool according to claim 1 , wherein the wheel includes a front flange, a rear flange and a coupling member, the front flange and the rear flange being integrally connected to each other via the coupling member.

13 . The driving tool according to claim 12 , wherein the plurality of engagement portions are positioned between the front flange and the rear flange.

14 . The driving tool according to claim 1 , wherein:

the wheel includes a front flange, a rear flange and a coupling member, the front flange and the rear flange being integrally connected to each other via the coupling member; and

the rear flange includes the extension groove arranged on a rear-side surface of the rear flange, the extension groove being arc-shaped.

15 . The driving tool according to claim 1 , wherein:

the holder includes a plurality of grease reservoirs;

at least one grease reservoir is on an outer circumferential side of an outer surface of the holder; and

at least one grease reservoir is on an inner circumferential side of the outer surface of the holder.

16 . The driving tool according to claim 15 , wherein the one of the plurality of engagement portions is positioned adjacent to the at least one grease reservoir on the outer circumferential side of the outer surface of the holder.

17 . A driving tool comprising:

a driver configured to move in a driving direction to drive a driving member;

a wheel configured to engage the driver, the wheel including a plurality of engagement portions;

an electric motor configured to rotate the wheel for moving the driver in a direction opposite to the driving direction via the plurality of engagement portions;

a holder attached to the wheel, the holder including at least one grease reservoir; and

at least one magnet arranged on the holder for detecting a rotation of the wheel.

18 . A driving tool comprising:

a driver configured to move in a driving direction to drive a driving member;

a wheel configured to engage the driver, the wheel including a plurality of engagement portions;

an electric motor configured to rotate the wheel for moving the driver in a direction opposite to the driving direction via the plurality of engagement portions;

a holder attached to the wheel, the holder including a plurality of grease reservoirs arranged on outer and inner circumferential sides of an outer surface of the holder;

a plurality of grease flow passages configured to connect at least one of the plurality of grease reservoirs and at least one of the plurality of engagement portions, the at least one of the plurality of engagement positions configured to engage the driver at a standby position;

at least one magnet arranged along a circumferential edge of the holder for detecting a rotation of the holder; and

at least one sensor for detecting a magnetism of the at least one magnet.

19 . The driving tool according to claim 18 , further comprising a controller for controlling the electric motor, the electric motor configured to receive one or more signals from the at least one sensor.