BACKGROUND OF THE INVENTION
Field of the Invention
[0001] The present invention relates to a coin hopper that drops coins into a through hole
of a rotating disk, sorts the coins one by one, and dispenses them and more particularly
relates to a small coin hopper having a rotating disk diameter that is approximately
two times the diameter of the coin. Furthermore, the present invention relates to
a coin hopper that has sufficient mechanical strength at attachment parts of a rotating
disk and a rotating shaft. The "coins" used in the present specification include substitute
currencies or similar things such as medals and tokens of game machines in addition
to coins which are current money.
[0002] The "small coin hopper" refers to a coin hopper in which the diameter of the rotating
disk is approximately two times that of the through hole, and only the single through
hole is provided.
Description of the Related Art
[0003] Small coin hoppers are used in a recycling-type coin receiving/dispensing device
of an automatic vending machine (for example, see Japanese Non-Examined Patent Publication
No.
2003-196695) and a coin change dispenser of a cash register of a supermarket (for example, see
Japanese Non-Examined Patent Publication No.
H7-306965).
[0004] The sizes of the small coin hoppers used therein are limited due to the relation
with installation space, and, if the diameters of the coins are large, the diameter
of the rotating disk is approximately two times the through hole, and only the single
through hole is provided.
[0005] As an example of the prior art techniques of the small coin hoppers, there is Japanese
Patent No.
5540190 (see FIG. 1 to FIG. 4, paragraph numbers 0010, 0011, 0017 to 0029) according to an
application of the present applicant. The coin hopper of Japanese Patent No.
5540190 is a coin hopper having a tubular hopper head storing coins in bulk; a rotating disk
disposed in a bottom hole of the hopper head, the rotating disk having a through hole
and a pushing part of the coin, the through hole allowing the coin to pass through
from an upper surface to a lower surface, the rotating disk tilted at a predetermined
angle, having a diameter less than approximately two times the through hole; and a
slide base disposed in parallel to a lower side of the rotating disk and allowing
the coin pushed by the pushing part to slide thereon; wherein the rotating disk has
an at least two-step configuration of an upper step part and a lower step part having
an step; the at least two-step configuration has the step formed on a slope; the through
hole is formed at an eccentric position of the rotating disk on the lower step part;
the step has a smaller radius than the radius of the rotating disk in a planar view;
the upper step part forms a circular arc shape having a center on the rotating disk
so as to have a crescent shape in a planar view; an end of the circular arc is in
contact with the through hole; and a middle of the circular arc is disposed in a periphery
side than an axial line of the rotating disk.
[0006] Generally, in a coin hopper, a rotating disk is fixed to a rotating shaft serving
as a drive shaft by using a screw serving as a fixing member. In that case, it is
fixed by screw-fixing with a screw hole of the rotating shaft in a state in which
the screw is inserted in a screw insertion hole formed coaxially with a central axis
of the rotating disk. Therefore, the rotating axis of the rotating disk and the axis
of the fixing member become coaxial. On the other hand, in the coin hopper of Japanese
Patent No.
5540190, since the through hole of the rotating disk reaches the vicinity of the rotating
axis of the rotating disk, the fixing member cannot be coaxially disposed with the
rotating axis of the rotating disk, and the fixing member has to be disposed at a
position eccentric with respect to the rotating disk. In that case, shear stress acts
on the fixing member along with the rotation of the rotating disk, and the fixing
member may be fractured due to fatigue. Normally, the rotating disk repeats forward
rotation and backward rotation in order to solve coin jamming in the coin hopper.
Therefore, the risk of fracture of the fixing member is further increased due to the
repetition. If a material having high mechanical strength is used as a material of
the fixing member as a countermeasure, the risk of the fracture can be reduced; however,
since the fixing member is screws, this cannot be readily used in consideration of
workability and cost.
SUMMARY OF THE INVENTION
[0007] The present invention has been accomplished in view of the above described circumstances,
and an object thereof is to provide a coin hopper capable of effectively preventing
fracture of the fixing member even if the rotating axis of the rotating disk and the
axis of the fixing member are not coaxial. It is another object of the present invention
to provide a coin hopper capable of increasing the fixation strength of the rotating
disk with respect to the rotating shaft while suppressing increase in cost even if
the rotating axis of the rotating disk and the axis of the fixing member are not coaxial.
Other objects of the present invention which are not specified herein will be elucidated
by below description and accompanying drawings.
[0008] In order to achieve these objects, the coin hopper according to the present invention
are configured in a below manner.
[0009] The coin hopper of the present invention comprising: a container storing coins in
bulk; a rotating disk disposed in a bottom hole of the container, the rotating disk
having a through hole and a pushing part of the coin, the through hole allowing the
coin to pass through from an upper surface to a lower surface, the rotating disk tilted
at a predetermined angle, having a diameter less than approximately two times the
through hole, and fixed to a rotating shaft; and a slide base disposed in parallel
to a lower side of the rotating disk and allowing the coin pushed by the pushing part
to slide thereon; wherein the through hole formed at an eccentric position of the
rotating disk, and the rotating disk fixed at a position eccentric from a central
axis on an end surface of the rotating shaft by a fixing member; characterized in
that the rotating disk and the rotating shaft are fixed by the fixing member in a
state in which a fitting projecting part formed on the end surface of the rotating
shaft and a fitting recessed part formed on a back surface side of the rotating disk
are fitted with each other.
[0010] The coin hopper of the present invention is provided with: the container storing
the coins in bulk; the rotating disk disposed in the bottom hole of the container,
the through hole allowing the coin to pass therethrough from the upper surface to
the lower surface, and the pushing part of the coin; and the slide base disposed in
parallel to the lower side of the rotating disk and allowing the coin pushed by the
pushing part to slide thereon. The rotating disk is tilted at the predetermined angle,
the diameter thereof is less than approximately two times the thorough hole, and the
rotating disk is fixed to the rotating shaft. The through hole is formed at the eccentric
position of the rotating disk, and the rotating disk is fixed by the fixing member
at the position eccentric from the central axis on the end surface of the rotating
shaft. The rotating disk and the rotating shaft are fixed by the fixing member in
the state in which the fitting projecting part formed on the end surface of the rotating
shaft and the fitting recessed part formed on the back surface side of the rotating
disk are fitted with each other. If the rotating disk is rotated, the acting force
in the rotating direction that acts between the rotating disk and the rotating shaft
is received by the fitting between the fitting projecting part and the fitting recessed
part. Therefore, the acting force in the rotating direction that acts on the fixing
member is significantly reduced. Therefore, fracture of the fixing member can be effectively
prevented. Moreover, since the fitting projecting part and the fitting recessed part
can be formed in manufacturing of the rotating disk and the rotating shaft, other
members are not required, and increase in cost can be suppressed as much as possible.
Thus, even if the rotating axis of the rotating disk and the axis of the fixing member
are not coaxial, fracture of the fixing member can be prevented, and the fixation
strength of the rotating disk with respect to the rotating shaft can be increased
while suppressing increase in cost.
[0011] In a preferred embodiment of the coin hopper of the present invention, the rotating
shaft has a first end surface and a second end surface respectively having semicircular
shapes in a plane; the first end surface is disposed so as to be approximately on
a same plane as the slide base; the second end surface is projecting with respect
to the first end surface; and the fitting projecting part is disposed on the second
end surface.
[0012] In another preferred embodiment of the coin hopper of the present invention, the
rotating disk has a central part projecting to a lower side with respect to the lower
surface of the rotating disk; and the fitting recessed part is extending from a periphery
side of the central part toward an axis of the rotating shaft.
[0013] In further another preferred embodiment of the coin hopper of the present invention,
the fitting projecting part has an approximately rectangular parallelepiped outer
shape; and the fitting recessed part is formed by a recessed groove.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014]
FIG. 1 is a perspective view showing a coin hopper of an embodiment of the present
invention.
FIG. 2 is a plan view of a state in which a hopper head of the coin hopper of FIG.
1 is removed.
FIG. 3 is an exploded perspective view of a main part in a state in which the hopper
head of the coin hopper of FIG. 1 is removed.
FIG. 4 is a perspective view of a state in which the hopper head and a rotating disk
of the coin hopper of FIG. 1 are removed.
FIG. 5 is a perspective view showing the rotating disk of the coin hopper of FIG.
1 from a front side.
FIG. 6 is a perspective view showing the rotating disk of the coin hopper of FIG.
1 from a back side.
FIG. 7 shows a fitted state of the rotating disk and a rotating shaft of the coin
hopper of FIG. 1; wherein (A) shows a front view, and (B) shows a right side view.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] Hereinafter, an embodiment of the present invention will be explained based on the
drawings attached.
[Embodiment]
[0016] A coin hopper 100 according to the present invention has a function to sort coins
C, which are stored in bulk, one by one and dispense them. As shown in FIG. 1 and
FIG. 2, the coin hopper 100 approximately includes a frame part 102, a base part 104,
a rotating disk 106, an ejecting part 108, and a hopper head 112.
[0017] First, the frame part 102 will be explained with reference to FIG. 1 and FIG. 2.
The frame part 102 has a function to support the base part 104, the rotating disk
106, the ejecting part 108, and the hopper head 112. The frame part 102 is injection-molded
resin, has a box shape which is approximately right triangular in a lateral view,
has an apex part tilted by about 30 degrees, and is approximately square in a planar
view. An electric motor, etc. for subjecting the rotating disk 106 to rotary drive
is built in the frame part 102.
[0018] Next, the base part 104 will be explained with reference to FIG. 2. The base part
104 has a function to retain the slide base 114 of the coins C, the ejecting part
108 of the coins C, and the hopper head 112. The base part 104 has a rectangular thick
plate shape detachably attached to an top part of the frame part 102 and is injection-molded
resin. At the center of an upper surface of the base part 104, an approximately circular
bottomed guide hole 116 having a diameter close to the full width of the base part
104 is formed. A peripheral wall 117 of the guide hole 116 in the upper side of the
tilt of the base part 104 is opened to form an outlet opening 118 of the coins C.
The outlet opening 118 of the guide hole 116 is formed at a trapezoidal part 120,
which is continued to an upper-side edge 119 of the base part 104. A slope 121 of
the trapezoidal part 120 is tilted with respect to an upper-left corner part 122 of
the base part 104 in FIG. 2. In order to improve abrasion resistance, in the guide
hole 116 and the trapezoidal part 120, the metal-made slide base 114 formed into a
shape similar to them is fitted in, and an upper surface of the slide base 114 is
formed on the same plane as an outlet upper surface 123 of the base part 104.
[0019] Next, the rotating disk 106 will be explained with reference to FIG. 2, FIG. 5, and
FIG. 6. The rotating disk 106 has a function to sort the coins C, which are in bulk
in the hopper head 112, one by one and dispense them. More specifically, the rotating
disk 106 is disposed in the vicinity of and parallel to the upper surface of the slide
base 114 in a bottom hole 134 of the later-described hopper head 112 and is fixed
to a rotating shaft 300, which is rotatably/drivably coupled to an electric motor
(not shown) built in the frame part 102. The rotating disk 106 is rotated in a counterclockwise
direction in FIG. 2 by the rotation of the electric motor based on dispensing signals
of the coins C. This counterclockwise rotation is referred to as forward rotation.
If coin jamming occurs and the rotating disk 106 does not rotate even when the electric
motor is in a forward rotation mode or if the coin(s) C is not dispensed for predetermined
time even when the ordered number of coin(s) C has not been dispensed, in other words,
if the ordered number of coin(s) C has not been dispensed and the coin(s) C has not
been dispensed for the predetermined time, the rotation of the electric motor is stopped,
and the electric motor repeats, a predetermined times, backward rotation (clockwise
direction in FIG. 2) and forward rotation again.
[0020] The rotating disk 106 is a thin-plate disk shape, wherein a lower step part 126 and
an upper step part 128 are formed. In other words, the thickness of the lower step
part 126 is formed to be thinner than the thickness of the upper step part 128 as
shown in FIG. 5. The lower step part 126 and the upper step part 128 are formed in
parallel to a lower surface 130 of the rotating disk 106. This is for reducing the
rotational resistance of the rotating disk 106 caused by the coins C.
[0021] As shown in FIG. 2, the lower step part 126 is formed in an oval (rugby ball) shape
in a planar view, and one circular through hole 132 penetrating from the upper surface
to the lower surface of the rotating disk 106 is formed at an eccentric position of
the rotating disk 106 and at a position at which part of the outer edge thereof is
adjacent to the periphery of the rotating disk 106. The diameter of the through hole
132 is a diameter slightly larger than the diameter of the used coin C and is slightly
smaller than the radius of the rotating disk 106. A circumferential surface 133 of
the through hole 132 is formed in an upwardly-widened mortar shape. This is for facilitating
dropping of the coin C into the through hole 132.
[0022] The upper step part 128 is formed in a crescent shape at an eccentric position of
the rotating disk 106, and an circular-arc-shaped edge thereof is formed in a slope
(not shown) having an angle of about 20 degrees with respect to the extended line
of the upper step part 128. In other words, an upper outer circumferential surface
140 of the upper step part 128 is partially formed in a spindle shape. The upper outer
circumferential surface 140 having the spindle shape in this manner is used in order
to prevent the coins C from leaning on the inner circumferential surface of the hopper
head 112 and being upright. An inward circular arc edge 138 has a second radius R2,
which is smaller than a first radius R1 of the rotating disk 106, and is a circular
arc having a center CE2 adjacent to the through hole 132 and on the rotating disk
106. In other words, a circular upper step part serving as a base of the upper step
part 128 is formed by a third radius R3, which is slightly smaller than the first
radius R1 of the rotating disk 106, and part of the circular upper step part is removed
in an oval shape or adding the crescent-shaped upper step part 128, thereby forming
the lower step part 126. The rotating disk 106 is, for example, a sintered object,
and the lower step part 126 and the upper step part 128 can be integrally molded.
[0023] As shown in FIG. 2, a right-side first end part 142 of the arc edge 138 is in contact
with the through hole 132 in the vicinity of the periphery of the rotating disk 106.
An intermediate part 144 of the arc edge 138 is positioned in the side closer to the
periphery than an axis CE1 of the rotating disk 106. A straight line L connecting
a distal end of a left-side second end part 146 of the arc edge 138 and a distal end
of the first end part 142 of the arc edge 138 is positioned to be closer to the opposite
side of the upper step part 128 than the axis CE1 of the rotating disk 106. In other
words, the first end part 142 positioned in the rear position side with respect to
the forward rotation direction of the rotating disk 106 is in contact with the through
hole 132 at a periphery of the rotating disk 106. Therefore, if the coin C, which
is in surface-contact with and placed on the lower step part 126, is positioned in
the upper side of the slope with respect to the through hole 132, the coin C can slide
down the upper surface of the lower step part 126 by the weight of its own and can
be dropped into the through hole 132. When the arc edge 138 is positioned above a
horizontal line which passes through the axis CE1, the coin C rolls and moves to the
side of the through hole 132 by the slope of the arc edge 138 and weight of the coin
C, the coin which contacted the surface of coin C with the lower step part 126 and
stopped by the arc edge 138. The coin C rolled and moved to the side of the through
hole 132 is opposed to and dropped into the through hole 132 at the first end part
142 at which the arc edge 138 is in contact with the through hole 132. The arc edge
138 is a slope and is connecting the step between the lower step part 126 and the
upper step part 128.
[0024] A cylindrical-shaped projection 148 is formed at the center of the upper surface
of the upper step part 128. The center of the upper surface means the middle in the
width direction and the longitudinal direction of a widest part of the crescent-shaped
upper step part 128. The projection 148 has a cylindrical shape having a diameter
of about 3 millimeters and has a height lower than the thickness of the coin C, and
an upper edge thereof is chamfered. The projection 148 can be made of metal and formed
by press-fitting a lower end part thereof into a vertical hole, which is bored in
the upper step part 128. However, the projection 148 can be also integrally molded
with the rotating disk 106. If the coin C is stopped by the projection 148 and is
rotated together with the rotating disk 106, when the coin C is positioned approximately
above the slope, the coin C slides down the upper surface of the rotating disk 106
and is dropped into the through hole 132.
[0025] On the back surface side of the rotating disk 106, an coin pushing part 152 is formed
so as to be adjacent to the through hole 132, be extending from a central part of
the rotating disk 106 to a periphery thereof, and form an involute curve having a
projecting shape toward the forward rotation direction. Therefore, when the rotating
disk 106 is rotated forward, the coin C dropped into the through hole 132 is turned
in the counterclockwise direction in FIG. 2 while the coin C is pushed by the coin
pushing part 152, the peripheral surface of coin C is guided by the peripheral wall
117 of the guide hole 116, and the lower surface of the coin C is guided by the slide
base 114. Then, in the vicinity of the outlet opening 118, the coin is guided to the
side of the outlet opening 118 by guiding pins 154 (see FIG. 4), which are projecting
above the slide base 114, and is ejected by the later-described ejecting part 108.
[0026] As shown in FIG. 5 and FIG. 6, in a forward-rotation-direction front position side
of the through hole 132 in the back surface side of the rotating disk 106, pushing
projections 156, which are projecting downward along the through hole 132, are formed.
Therefore, if the rotating disk 106 is rotated backward, the coin C is pushed in the
clockwise direction in FIG. 2 by the pushing projections 156 and is turned in the
clockwise direction in FIG. 2 while the peripheral surface of the coin C thereof is
guided by the peripheral wall 117 of the guide hole 116 and the lower surface of the
coin C is guided by the slide base 114. In the vicinity of the outlet opening 118,
the coin C contacts the guiding pins 154. However, as is publicly known, since the
guiding pins 154 elastically retreat into the slide base 114, the coin C is turned
together with the rotating disk 106 without being guided by the guiding pins 154 to
the side of the outlet opening 118.
[0027] Next, the ejecting part 108 will be explained with reference to FIG. 2. The ejecting
part 108 has a function to sort the coins C one by one and dispense them. In the present
embodiment, the ejecting part 108 includes a fixed roller 162 and a movable roller
172.
[0028] The fixed roller 162 is disposed to be adjacent to the guide hole 116 in the upper
side of the slope of the base part 104. The fixed roller 162 is rotatably attached
to an upper end part of a supporting shaft 168, which is penetrating through a long
hole 166 formed in the base part 104. The supporting shaft 168 is disposed in the
back surface side of the base part 104. The supporting shaft 168 is turnably supported
by a fixed shaft (not shown) in the lower side of the rotating disk 106. The supporting
shaft 168 is fixed to a lever (not shown), which is biased in the clockwise direction
in FIG. 2 by a spring (not shown). The spring force thereof has an extremely large
spring constant with respect to a later-described spring 194 for ejection, and the
fixed roller 162 is not moved when in a case of normal dispensing of the coin C. However,
if extremely large force works, it can be moved within the range of the long hole
166.
[0029] The movable roller 172 has a function to eject the coin C, which has been pushed
into the part between the movable roller and the fixed roller 162 by the rotating
disk 106. The movable roller 172 is turnably supported by a shaft 178, which is projecting
downward from a distal end of a swing lever 176 turnably supported by a second supporting
shaft 174. The second supporting shaft 174 is projecting upward from an end of an
arc-shaped position-adjusting bracket 182, which is disposed to be adjacent to the
guide hole 116 in a corner part in the opposite side of the fixed roller 162 of the
base part 104.
[0030] The position-adjusting bracket 182 is fixed onto the upper surface of the base part
104 by a pair of screws 186a and 186b, which penetrate through an arc-shaped long
hole 184 formed by a predetermined radius using the axis of the rotating disk 106
as a center and are screwed into the base part 104. By virtue of this configuration,
the movable roller 172 is subjected to position adjustment within the range of the
arc-shaped long hole 184 so that the movable roller 172 is at an optimum position
in the relation with the fixed roller 162 with respect to the diameter of the used
coin C. A spring stopper 188 is projected upward from an end of the position-adjusting
bracket 182, and a second end 192 of the swing lever 176 contacts a lower end of the
spring stopper 188 and regulates a standby position (the position of FIG. 2) of the
movable roller 172 in a standby state.
[0031] The middle of the helical spring 194 is wound around the outer circumference of the
second supporting shaft 174, a first end thereof is stopped by the swing lever 176,
a second end thereof is stopped by the spring stopper 188, and turning force in the
counterclockwise direction in FIG. 2 is applied to the swing lever 176. If the movable
roller 172 is positioned at the standby position, the interval between the movable
roller and the fixed roller 162 is retained at an interval smaller than the diameter
of the coin C. If the coin C guided by the guiding pins 154 is pushed into the part
between the fixed roller 162 and the movable roller 172 by the pushing part 152 of
the rotating disk 106, the swing lever 176 is turned in the clockwise direction in
FIG. 2, and, immediately after the straight line passing through the center of the
coin C passes through contact points with the fixed roller 162 and the movable roller
172, the coin is ejected toward a later-described sensor 212 by the movable roller
172 based on the spring force of the helical spring 194.
[0032] Next, with reference to FIG. 1, the hopper head 112 will be explained. The hopper
head 112 has a function to store the coins C, which are in bulk, above the rotating
disk 106. In other word, the hopper head 112 functions as a container storing the
coins C. The hopper head 112 as a whole has a vertical tubular shape, a lower end
part 196 thereof is formed in a circular shape, an upper end part 198 thereof is formed
in a rectangular shape, an intermediate part 202 is formed in a slope so as to smoothly
connect the upper end part 198 and the lower end part 196, and the lower end part
196 is detachably fixed to the base part 104.
[0033] Next, the sensor 212 will be explained with reference to FIG. 1 and FIG. 2. The sensor
212 has a function to detect the coin C ejected by the ejecting part 108. The sensor
212 is, for example, a magnetic sensor 214. This is for a reason that the coin C can
be detected without being affected by dust, etc. The magnetic sensor 214 has a lateral
gate shape and is fixed to a metal-made bracket 226, which is fixed to a lateral surface
of the frame part 102, so that the ejected coin(s) C passes through a coin passing
part (not shown) between an upper supporting part 218 thereof and a lower supporting
part thereof (not shown).
[0034] Next, the connecting structure of the rotating disk 106 to the rotating shaft 300
will be explained. First, the rotating shaft 300 will be explained. The rotating shaft
300 has a function to rotatably support the rotating disk 106. The rotating shaft
300 is drivably coupled to a drive shaft of the electric motor (not shown) via a reduction
gear (not shown) and is rotated by the electric motor. The rotating shaft 300 is made
of metal having abrasion resistant (in other words, high hardness). The rotating shaft
300 is a rod of cross sectional view circle. The rotating shaft 300 has a large diameter
part 312 and a small diameter part 314 and has a first end surface 301 and a second
end surface 302 at an upper end thereof. The first end surface 301 and the second
end surface 302 have semicircular shapes in a planar view, and the first end surface
301 is positioned below the second end surface 302. In other words, a step is formed
between the first end surface 301 and the second end surface 302. The first end surface
301 is positioned so as to be approximately on the same plane as the slide base 114,
and the second end surface 302 is projecting from the slide base 114 to the upper
side. This is for a reason so that a predetermined gap is formed between the back
surface side of the rotating disk 106 and the slide base 114 when the rotating disk
106 is fixed to the second end surface 302. On the second end surface 302, a projecting
part 304 having an approximately rectangular shape in a planar view is integrally
formed with the rotating shaft 300. In other words, the projecting part 304 has an
approximately rectangular parallelepiped outer shape having a width W, a length L1,
and a height H. The projecting part 304 is disposed to be eccentric to a rotating
axis RA of the rotating shaft 300. In both sides of the projecting part 304 of the
second end surface 302, two screw holes 306 are formed. These two screw holes 306
are also disposed to be eccentric with respect to the rotating axis RA.
[0035] On the other hand, on a central part 324 projecting to the lower side with respect
to the lower surface 130 of the rotating disk 106, a recessed part 322, which can
be fitted with the projecting part 304 of the rotating shaft 300 is formed. The recessed
part 322 is a recessed groove 323 having the width W and is extending from a periphery
325 side of the central part 324 toward the rotating axis RA 132. In both sides of
the recessed groove 323, two screw insertion holes (counterbore holes) 326 are formed
at the positions eccentric with respect to the rotating axis RA.
[0036] Two screws 330 are screwed in the screw holes 306 of the rotating shaft 300 via the
screw insertion holes 326 of the rotating disk 106. These two screws 330 are disposed
at the positions eccentric with respect to the rotating axis RA and function as fixing
members 332, which fix the rotating disk 106 and the rotating shaft 300.
[0037] Fixation of the rotating disk 106 to the rotating shaft 300 is carried out in a below
manner. First, while the projecting part 304 of the rotating shaft 300 is fitted into
the recessed groove 323, which is formed on the back surface side of the rotating
disk 106, positioning is carried out so that the screw insertion holes 326 of the
rotating disk 106 and the screw holes 306 of the rotating shaft 300 become coaxial.
In this state, the two screws 330 are inserted in the screw insertion holes 326 of
the rotating disk 106, and the screws 330 are rotated and screw-fixed to the rotating
shaft 300 until the second end surface 302 of the rotating shaft 300 and the back
surface of the central part 324 of the rotating disk 106 are brought into close contact
with each other. In this manner, in the state in which the projecting part 304 formed
on the second end surface 302 of the rotating shaft 300 and the recessed groove 323
formed on the back surface side of the rotating disk 106 are fitted with each other,
the rotating disk 106 and the rotating shaft 300 are fixed by the screws 330.
[0038] If the rotating disk 106 is rotated by the rotation of the rotating shaft 300 in
this state, the acting force in the rotating direction which works between the rotating
disk 106 and the rotating shaft 300 is received by the fitting of the lateral surfaces
of the projecting part 304 and the lateral surfaces of the recessed groove 323. Therefore,
the acting force in the rotating direction which works on the screws 330 is significantly
reduced. Therefore, fracture of the screws 330 can be effectively prevented. Moreover,
since the projecting part 304 and the recessed groove 323 can be formed upon manufacturing
of the rotating disk 106 and the rotating shaft 300, other members are not required,
and cost increase can be suppressed as much as possible.
[0039] In the present embodiment, the projecting part 304 of the rotating shaft 300 has
an approximately rectangular parallelepiped outer shape, and the recessed part 322
of the rotating disk 106 is the recessed groove 323. However, these are not limited
thereto, and the outer shape of the projecting part 304 and the inner shape of the
recessed part 322 can be variously changed. For example, the projecting part 304 may
have a cylindrical shape, and the recessed part 322 may have a circular shape in a
planar view. However, from the viewpoint of increasing the area of receiving the acting
force in the rotating direction as much as possible, it is effective that the projecting
part 304 has an approximately rectangular parallelepiped outer shape and that the
recessed part 322 of the rotating disk 106 is the recessed groove 323 like the present
embodiment.