JP2017096200A - Coolant pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coolant pump which can suppress an increase of a discharge amount even when the number of revolutions of an internal combustion engine is increased.SOLUTION: A coolant pump comprises a rotor R to which a drive force is transmitted via a clutch mechanism C for connecting and disconnecting the drive force of a rotating body 3 driven by an internal combustion engine E. The clutch mechanism C comprises a contact transmission member 13 which is displaceable in a direction separating from the rotating body 3 accompanied with the rotation of the rotor R by being supported by the rotor R, and an energization member 14 which applies an energization force to the contact transmission member 13 in a direction where the contact transmission member comes into contact with the rotating body 3.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a coolant pump that is driven by a driving force of an internal combustion engine and sends a coolant of the internal combustion engine.

  In Patent Document 1, a drive shaft is supported as a coolant pump so as to be rotatable with respect to a housing, a pump-side pulley is provided at an outer end of the drive shaft, a rotor is provided at an inner end of the drive shaft, and a pump-side pulley is provided. And a technique of driving a rotor by a driving force of an engine by winding a belt around an engine pulley.

  In this technique, a flow is generated in the cooling water by the rotation of the rotor, and the rotor rotates and discharges the cooling water when the engine is operating.

  Further, Patent Document 2 includes a fluid joint between a pump shaft to which an impeller of a water pump is connected and a water pump pulley that is rotated by the driving force of the engine. The fluid joint is a water pump pulley due to the viscosity of the fluid. A technique for transmitting the rotational force of the pump to the pump shaft is shown.

  With this technology, the fluid joint has a small slip amount when the engine is operating at a low speed to ensure the necessary rotation speed of the water pump, and the slip amount is large when the engine is operating at a high speed to prevent excessive rotation of the water pump. It is configured.

JP 2014-227984 A JP 2001-342832 A

  Engines (internal combustion engines) provided in passenger cars tend to be downsized, and many of them are equipped with a supercharger to increase output. Further, such an engine generates a large amount of heat even at a low speed, and requires a water amount of cooling water that enables heat radiation corresponding to this.

  The water pump driven by the engine has a simple structure and is less expensive and less expensive than the one driven by the electric motor. Therefore, as shown in Patent Documents 1 and 2, a structure driven by an engine is used.

  In addition, when the water pump driven by the engine is configured to supply a relatively large amount of cooling water at a low speed, the engine is operated at a high speed in a state where the flow of the cooling water is blocked as in warm-up. When it rotates, the pressure of the cooling water rises, and the water hose may come off (hose disconnection).

  For such inconvenience, the water pump disclosed in Patent Document 2 can suppress the increase in the rotation speed of the impeller by increasing the slip at the fluid joint as the engine rotates at a higher speed. Not only does it cause heat generation because of transmission, but the configuration is also likely to be complicated and there is room for improvement.

  For these reasons, there is a need for a coolant pump that has a configuration that is driven by an internal combustion engine and that suppresses an increase in the discharge amount of the pump even if the rotational speed of the internal combustion engine increases.

The present invention provides a rotating body that rotates about a rotating shaft center by a driving force of the internal combustion engine, a rotor that circulates coolant of the internal combustion engine by rotating about the rotating shaft core, A clutch mechanism for intermittently transmitting the rotational driving force transmitted to the rotor,
When the clutch mechanism rotates together with the rotor, a contact transmission member that is displaceable in a direction away from the rotating body by centrifugal force and a biasing force that displaces the contact transmission member in a direction to contact the rotating body act. And an urging member to be moved.

According to this, when the rotating body rotates at a low speed, the contact transmission member is kept in contact with the rotating body by the urging force of the urging member (the clutch mechanism is maintained in the transmission state). The rotational driving force is transmitted to the rotor by static friction acting between the transmission member and the rotating body. Next, after the rotational speed of the rotating body increases and the contact transmission member starts to move away from the rotating body due to centrifugal force, slip occurs before the rotating body and the contact transmission member separate ( The clutch mechanism is in a half-clutch state), and the rotational driving force is transmitted to the rotor by dynamic friction acting between the rotating body and the contact transmission member. Since this transmission mode involves slip, the rotational speed of the rotor is reduced and the rotor can be driven smoothly without greatly changing the rotational speed.
In particular, in this configuration, when the rotating body rotates at a high speed, the contact transmission member is separated from the rotating body for a short time by the centrifugal force acting on the contact transmission member (the clutch mechanism is cut off). It can also be understood that the mechanism returns to the transmission state, and that the blocking state and the transmission state are repeated in a short time. Even in this transmission mode, the rotor speed can be reduced and the rotor can be driven smoothly without greatly changing the speed.
Therefore, a coolant pump having a configuration that is driven by an internal combustion engine and that suppresses an increase in pump discharge when the rotational speed of the internal combustion engine increases is configured.

The present invention has a configuration in which the rotating body is formed in an axial shape, and the rotor is arranged at a position surrounding the rotating body,
The contact transmission member is slidably supported with respect to the guide body in a posture along the radial direction of the rotor, and the urging member urges the contact transmission member to project toward the outer peripheral surface of the rotating body. May be.

  According to this, the contact transmission member is slidably supported on the guide body, and the biasing member is attached to the contact transmission member by adopting a simple configuration in which the biasing member is urged in the direction of contact with the rotating body. The clutch mechanism can be configured such that a force is applied and the contact member can be displaced from the rotating body in the separation direction against the urging force by the action of centrifugal force.

  In the present invention, a plurality of the contact transmission members may be provided at equal intervals in the circumferential direction around the rotation axis.

  According to this, a plurality of contact transmission members can be brought into contact with the outer peripheral surface of the rotating body equally. For example, a load in a bending direction is applied to the rotating body as in a configuration including a single contact transmission member. Does not act, nor does it unbalance the rotation.

  In the present invention, the clutch mechanism may be disposed in the coolant.

  According to this, since noise diffusion generated when the contact transmission member comes into contact with the rotating body can be suppressed by the coolant, an improvement in quietness is realized. Further, even if the contact transmission member generates heat, it can be cooled by the coolant.

  In the present invention, a friction material may be provided on at least one of two transmission surfaces that contact each other and transmit a rotational driving force between the rotating body and the contact transmission member.

  According to this, by providing the friction material, it is possible to suppress the wear of the contact portion between the transmission surface of the rotating body and the transmission surface of the contact transmission member, and to drive the rotation with high efficiency by setting the friction coefficient of the friction material. Power can be transmitted.

  In the present invention, a recess in which the contact transmission member is fitted to a transmission surface of the rotating body that contacts the contact transmission member may be formed.

  According to this, in a state where the contact transmission member is fitted in the recess, reliable transmission is possible without causing slip. Further, when the rotational speed of the rotating body is increased, the contact transmission member can be detached from the recess by the centrifugal force acting on the contact transmission member.

It is sectional drawing of the water pump provided with the clutch mechanism. It is sectional drawing of a clutch mechanism. It is a graph which shows the relationship between the rotation speed of a drive shaft, and discharge amount. It is sectional drawing of the clutch mechanism of another embodiment (a). It is sectional drawing of the clutch mechanism of another embodiment (b). It is sectional drawing of the clutch mechanism of another embodiment (c). It is sectional drawing of the clutch mechanism of another embodiment (d).

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
〔overall structure〕
As shown in FIGS. 1 and 2, a drive pulley 2 around which a drive belt 1 driven by a driving force of an engine E as an internal combustion engine is wound is provided, and a drive shaft 3 (of a rotating body) connected to the drive pulley 2 is provided. An example), a clutch mechanism C that intermittently transmits and receives the rotational driving force transmitted from the drive shaft 3, and a rotor R that rotates by the rotational driving force transmitted from the clutch mechanism C are configured as a water pump WP as a coolant pump. ing.

  This water pump WP supplies cooling water (an example of cooling liquid) of a water jacket (not shown) of an engine E provided in a vehicle to a radiator (not shown). The drive belt 1 is wound around an output pulley of a crankshaft of the engine E.

  The water pump WP includes a housing 4, and a drive shaft 3 (an example of a rotating body) is supported by a bearing portion 4 </ b> A formed in the housing 4 via a bearing 5 so as to be rotatable around a rotation axis X. Has been. The drive pulley 2 is connected and fixed to the outer end portion of the drive shaft 3, and the rotor R is supported on the inner end portion of the drive shaft 3 so as to be relatively rotatable about the rotation axis X, and between the drive shaft 3 and the rotor R. Is provided with a clutch mechanism C. A seal 6 is provided between the housing and the drive shaft to prevent leakage of cooling water.

  FIG. 1 shows a configuration in which the housing 4 of the water pump WP is connected and fixed at a position covering the pump chamber S formed in a concave shape on the outer wall portion of the cylinder block or the like of the engine E. The rotor R is disposed inside the pump chamber S, and is configured as a centrifugal type in which the rotor body 8 includes a plurality of impellers 9.

  The rotor body 8 has a cylindrical portion 8a centered on the rotation axis X, and a flange-like portion 8b in a posture orthogonal to the rotation axis X is integrally formed on one end side of the cylindrical portion 8a. A plurality of impellers 9 are provided for the shaped portion 8b. Further, a sleeve portion 8c is provided on the other end side of the cylindrical portion 8a. The sleeve portion 8c is externally fitted to the small diameter portion 3a of the drive shaft 3 so as to be rotatable relative to the cylindrical portion 8a. By doing so, the rotor R is supported so as to be rotatable relative to the drive shaft 3 around the rotation axis X.

[Clutch mechanism]
The clutch mechanism C maintains a transmission state in which the rotational driving force of the drive shaft 3 is transmitted to the rotor R when the drive shaft 3 rotates at a low speed, and the rotor R exceeds a predetermined rotational speed (the rotational speed per unit time). In addition, the drive shaft 3 is configured to be switched to a cut-off state that cuts off the rotational driving force.

  The clutch mechanism C is supported by a plurality of guide bodies 12 provided in a posture along the radial direction with respect to the cylindrical portion 8a of the rotor R with respect to the rotation axis X, and is slidably supported by the respective guide bodies 12. The contact transmission member 13, a coil-like biasing member 14 disposed on the coaxial core with the guide body 12 so as to project and bias each contact transmission member 13 in the direction of the rotation axis X, and the contact transmission member 13 And a passive friction material 15 that is supported by and is in contact with the outer periphery of the drive shaft 3.

  A plurality (three in this embodiment) of guide bodies 12 are supported at positions that are equally spaced in the circumferential direction of the cylindrical portion 8a. The contact transmission member 13 is formed with an arcuate transmission portion 13a extending along the circumferential direction of the drive shaft 3, and a concave insertion portion 13b through which the guide body 12 is inserted. The transmission portion 13a has a drive shaft. A concave transmission surface 13c having the same radius as that of the drive shaft 3 is formed along the outer periphery of the drive shaft 3, and the passive friction material 15 is supported on the transmission surface 13c. In the state where the passive friction material 15 of the three contact transmission members 13 is in contact with the outer periphery of the drive shaft 3, the dimensional relationship in the circumferential direction is set so that the three transmission portions 13a surround the outer periphery of the drive shaft. . Further, the clutch mechanism C is disposed at a position where all parts are immersed in the cooling water.

  In this clutch mechanism C, the passive friction material 15 is made of a material having excellent wear resistance and a predetermined friction coefficient. In addition, although the thing which shape | molded the resin fiber in plate shape as this passive friction material 15 is assumed, you may use a resin material.

  That is, the cylindrical portion 8a of the rotor R is disposed at a position surrounding the drive shaft 3, and with respect to the plurality of guide bodies 12 formed in a radial posture around the rotational axis X with respect to the cylindrical portion 8a. The contact transmission member 13 is slidably supported. Further, the contact transmission member 13 is urged by the urging member 14 so as to contact the outer peripheral surface of the drive shaft 3. Thereby, with the rotation of the rotor R, the contact transmission member 13 can be separated from the outer peripheral surface of the drive shaft 3 by the action of centrifugal force.

  With such a configuration, when the rotational speed of the drive shaft 3 rotates below a predetermined value N, the passive friction material 15 of the contact transmission member 13 biases the outer peripheral surface of the drive shaft 3. The drive shaft 3 and the rotor R rotate together by static friction between them. This is the transmission state of the clutch mechanism C, and the rotor R is driven to rotate at the same speed as the drive shaft 3. As shown in FIG. 3 as a low speed region discharge amount Q1 in FIG. 3, the discharge amount of the cooling water from the water pump WP is proportional to the rotational speed of the drive shaft 3 by a predetermined proportional constant.

  On the other hand, when the rotor R rotates beyond a predetermined value N set in advance, the passive friction material 15 of the contact transmission member 13 resists the biasing force of the biasing member 14 by the action of centrifugal force. The displacement starts in a direction away from the outer peripheral surface of the drive shaft 3. Along with this displacement, slip is caused between the passive friction material 15 of the contact transmission member 13 and the outer peripheral surface of the drive shaft 3, and the rotational driving force of the drive shaft 3 is transmitted to the contact transmission member 13 by dynamic friction between them. Tell the rotor R. Since this transmission state is a half-clutch state and slip occurs between the drive shaft 3 and the contact transmission member 13, as a result, a rotational driving force having a rotational speed smaller than the rotational speed of the drive shaft 3 is transmitted.

  The clutch mechanism C can be regarded as a transmission form in which transmission is performed by repeating the transmission state and the cutoff state in a short time. Even in this transmission mode, since slip occurs between the drive shaft 3 and the contact transmission member 13, as a result, a rotational driving force having a rotational speed smaller than the rotational speed of the drive shaft 3 is transmitted.

  The state in which the water pump WP is driven by the transmission accompanied by the slip is shown as a high speed region discharge amount Q2 in FIG. 3, and at this high speed region discharge amount Q2, the discharge amount of the cooling water of the water pump WP is driven. It is proportional to the rotational speed of the shaft 3 by a proportional constant smaller than the proportional constant of the low speed region discharge amount Q1.

  In the graph of FIG. 3, the horizontal axis represents the rotational speed of the drive shaft 3, and the vertical axis represents the discharge amount of the cooling water from the water pump WP. Until the rotational speed of the drive shaft 3 reaches a predetermined value N, the clutch mechanism C maintains the transmission state, so that the discharge amount of the water pump WP discharges the cooling water in a proportional relationship indicated by the low-speed range discharge amount Q1. When the rotational speed exceeds a predetermined value N, the clutch mechanism C switches to the half-clutch state. Therefore, the discharge amount of the water pump WP discharges the cooling water in a proportional relationship indicated by the high-speed range discharge amount Q2.

  Considering the graph of the figure, when the clutch mechanism C repeats the transmission state and the shut-off state, the rotation of the drive shaft 3 is directly received in the transmission state. Therefore, it is considered that the discharge amount increases. On the other hand, when the rotational driving force of the drive shaft 3 is transmitted to the contact transmission member 13 by dynamic friction and transmitted to the rotor R, the posture of the high speed region discharge amount Q2 is parallel to the horizontal axis (becomes a horizontal posture). However, when the influence of the spiral water flow around the rotation axis X is taken into account as the drive shaft 3 rotates, the discharge amount increases in a relationship proportional to the rotation speed. For this reason, the high-speed area discharge amount Q2 is drawn in an inclined posture.

[Operation / Effect of Embodiment]
For example, assuming an engine E (for example, a small in-line engine or a V-type engine) configured to obtain a high output at low speed rotation even if it is relatively small by providing a supercharger, an engine of this configuration E requires a sufficient amount of cooling water even at low speeds. When the discharge amount of the water pump WP is set so as to supply the cooling water corresponding to this, the cooling water is excessively supplied when the engine E rotates at a high speed. On the other hand, in the water pump WP shown in the embodiment, it is possible to suppress the inconvenience of excessive supply of cooling water during high-speed rotation, and the rotor R can be smoothly driven without greatly changing the rotation speed.

  Further, in the engine E configured as described above, when the rotational speed of the engine E increases in a state where the flow of the cooling water to the radiator is interrupted during warm-up, the discharge pressure of the water pump WP sends the cooling water. It acts on the hoses and causes not only the leakage of cooling water but also the disconnection of the hoses. On the other hand, in the water pump WP shown in the embodiment, since the discharge amount of the cooling water is suppressed even when the engine E rotates at a high speed during warm-up, the leakage of the cooling water and the disconnection of the hose are not caused.

  In particular, in the water pump WP, a plurality of contact transmission members 13 are contacted at equal intervals in the circumferential direction of the outer periphery of the drive shaft 3, so that balanced rotation is performed and a biased load is applied to the drive shaft 3. There is nothing. By providing the plurality of contact transmission members 13, for example, even when one contact transmission member 13 falls into a malfunctioning state, the driving force of the drive shaft 3 is applied to the rotor R via the other contact transmission members 13. It is also possible to communicate.

  Further, in the water pump WP having this configuration, since the contact transmission member 13 of the clutch mechanism C is disposed in the cooling water, the contact transmission member 13 falls into a state of intermittent contact with the outer periphery of the drive shaft 3. However, it is possible to suppress the contact sound.

[Another embodiment]
In addition to the above-described embodiments, the present invention may be configured as follows (the components having the same functions as those of the embodiments are given the same numbers and symbols as those of the embodiments).

(A) As shown in FIG. 4, the drive friction material 20 is provided on the outer periphery of the drive shaft 3, and the clutch mechanism C is brought into direct contact with the drive friction material 20 with the transmission surface 13 c of the contact transmission member 13. You may comprise so that the transmission state of may be produced.

  Also in this alternative embodiment, the driving friction material 20 is made of a material having excellent wear resistance and a predetermined friction coefficient, like the passive friction material 15 described in the embodiment. As a result, when the clutch mechanism C is in the transmission state, the driving force of the driving shaft 3 is transmitted to the contact transmission member 13 via the driving friction material 20 to realize the driving rotation of the rotor R.

  In particular, as a modification of this another embodiment (a), the clutch mechanism C is configured so that the drive friction material 20 is provided on the outer periphery of the drive shaft 3 and the passive friction material 15 is provided on the transmission surface 13 c of the contact transmission member 13. It is also possible to do.

(B) As shown in FIG. 5, an engagement recess 3g is formed on the outer periphery of the drive shaft 3, and the contact transmission member 13 is configured to be engageable with and disengageable from the engagement recess 3g. In this configuration, the contact transmission member 13 is formed in a rod shape, and the guide body 12 is formed in a cylindrical shape so that the contact transmission member 13 is slidably mounted. The contact transmission member 13 includes a through pin 13f. A slit 12a through which the through pin 13f is inserted is formed along the longitudinal direction of the guide body 12, and the contact transmission member 13 is protruded through the through pin 13f. A biasing member 14 is provided so as to bias.

  In this configuration, the state where the contact transmission member 13 is engaged with the engagement recess 3g can be maintained, so that the clutch mechanism C is maintained in the transmission state, thereby realizing reliable transmission. In addition, when the rotational speed of the drive shaft 3 increases and the contact transmission member 13 is separated from the engagement recess 3g by the action of centrifugal force, and then the clutch mechanism C shifts to the transmission state by the urging force of the urging member 14. Since the contact transmission member 13 is engaged with the engaging recess 3g, reliable transmission can be performed in a short time.

  In other words, when the contact transmission member 13 is engaged with the engagement recess 3g, the drive transmission is reliably transmitted without slipping, and the contact transmission member 13 is driven away from the engagement recess 3g by the action of centrifugal force. The state where the force is interrupted is repeated, and the rotational speed of the rotor R is reduced while performing reliable transmission. Incidentally, the shape of the engaging recess 3g is a cross-sectional shape slightly larger than the cross section of the protruding end of the contact transmission member 13 so that the protruding end of the contact transmission member 13 is fitted in the direction approaching the rotation axis X. It may be formed in a hollow shape.

(C) As shown in FIG. 6, a contact transmission member that includes a pair of swing shafts 22 that are parallel to the rotation axis X with respect to the rotor R, and that can swing about the respective swing shafts 22. 13, a passive friction material 15 is provided at the oscillating ends of the contact transmission members 13, and an urging member 14 formed of a tension spring is provided so that the oscillating ends of the pair of contact transmission members 13 are attracted to each other.

  In this configuration, since the urging force of the urging member 14 acts so that the swinging ends of the pair of contact transmission members 13 are simultaneously pulled toward the outer periphery of the drive shaft 3, the passive friction material 15 is simultaneously moved to the drive shaft. 3 can be brought into contact with each other to ensure reliable transmission. Further, since the contact transmission member 13 is configured to swing, the operation when the swing end of the contact transmission member 13 is displaced in a direction approaching or separating from the drive shaft 3 becomes smooth.

(D) As shown in FIG. 7, a drive disk 25 (an example of a rotating body) that rotates integrally with the drive shaft 3, a disk-shaped contact transmission member 13 that is movable along the rotation axis X, and a contact transmission member The clutch mechanism C is configured to include a biasing member 14 that biases 13 and a centrifugal force acting mechanism 27 that applies a force that causes the contact transmission member 13 to be separated from the drive disk 25 by centrifugal force as the rotor R rotates. .

  In this configuration, the contact transmission member 13 is supported so as to be rotatable relative to the drive shaft 3 and movable in a direction along the rotation axis X. As a result, the contact transmission member 13 can be switched between a position in contact with the drive disk 25 and a position in which the contact transmission member 13 is separated. The centrifugal force acting mechanism 27 includes a swing arm 27a whose base end is swingably supported with respect to the rotor body 8 of the rotor R, a weight 27b provided at the swing end of the swing arm 27a, and a swing arm. An operating portion 27c is provided that applies a force along the rotation axis X to the contact transmission member 13 as the moving arm 27a swings. In this configuration, a friction material may be provided on the contact surface between the drive disk 25 and the contact transmission member 13.

  With such a configuration, when the rotational speed of the drive shaft 3 is less than the set value, the contact transmission member 13 maintains a state of contacting the drive disk 25 by the urging force of the urging member 14 (the clutch mechanism C is Therefore, the rotational driving force of the drive disk 25 is transmitted to the rotor R via the centrifugal force acting mechanism 27. When the rotational speed of the drive shaft 3 reaches a set value or more, the swing arm 27a swings as the centrifugal force acting on the weight 27b of the centrifugal force acting mechanism 27 increases, and the swing force is actuated. The part 27c displaces the contact transmission member 13 in the direction away from the drive disk 25, and the clutch mechanism C enters the half-clutch state.

  Thereby, the rotational driving force accompanied by slip is transmitted from the drive shaft 3 to the rotor R, and the discharge amount of the water pump WP can be reduced. In this other embodiment, since transmission is performed via a wide contact surface between the drive disk 25 and the contact transmission member 13, stable driving is possible.

(E) In the above-described embodiment and each of the separate embodiments, the clutch mechanism C is configured to create a transmission state and a cutoff state by direct contact between the drive shaft 3 and the contact transmission member 13. The clutch mechanism C may be configured by arranging the contact transmission member 13 so as to contact the parts rotating integrally with the drive shaft 3 to be in a transmission state.

(F) The clutch mechanism C may be configured not to contact cooling water (cooling liquid) at the center position of the rotor R, for example, so that the responsiveness of the contact transmission member 13 is improved.

  The present invention can be used for a coolant pump driven by a driving force of an internal combustion engine.

3 Rotating body (drive shaft)
3g recess (engagement recess)
12 Guide body 13 Contact transmission member 14 Biasing member 15 Friction material (passive friction material)
20 Friction material (drive friction material)
25 Rotating body (drive disk)
C Clutch mechanism E Internal combustion engine
R Rotor X Rotating shaft core

Claims (6)

A rotating body that rotates about the rotation axis by the driving force of the internal combustion engine, a rotor that circulates the coolant of the internal combustion engine by rotating about the rotation axis, and the rotor is transmitted to the rotor A clutch mechanism for intermittently rotating driving force,
When the clutch mechanism rotates together with the rotor, a contact transmission member that is displaceable in a direction away from the rotating body by centrifugal force and a biasing force that displaces the contact transmission member in a direction to contact the rotating body act. And a biasing member to be cooled. The rotating body is formed in a shaft shape, and the rotor is arranged at a position surrounding the rotating body,
The contact transmission member is slidably supported with respect to the guide body in a posture along the radial direction of the rotor, and the urging member urges the contact transmission member to project toward the outer peripheral surface of the rotating body. The coolant pump according to claim 1.   The coolant pump according to claim 2, wherein the plurality of contact transmission members are provided at equal intervals in a circumferential direction centering on the rotation axis.   The coolant pump according to any one of claims 1 to 3, wherein the clutch mechanism is disposed in the coolant.   5. The friction material according to claim 1, wherein a friction material is provided on at least one of two transmission surfaces that contact each other and transmit a rotational driving force among the rotating body and the contact transmission member. Coolant pump. The coolant pump as described in any one of Claims 1-5 in which the recessed part which the said contact transmission member fits is formed with respect to the transmission surface which the said contact transmission member contacts among the said rotary bodies.

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