Power transmission device, recording device and gear

Abstract

To solve a problem in which when a shape of a gear is asymmetric in an axial direction of a rotational shaft, an assembly worker may install the gear in a wrong direction.SOLUTION: A power transmission device comprises a gear having an axial hole that is fitted onto a shaft, and a restriction member that is fitted into a fitting part formed on the shaft and restricts movement of the gear toward a free end of the shaft. The gear has a first end part that is the outermost end part in a first direction, and a second end part that is the outermost end part in a second direction. When the second end part of the gear is located at the side of the free end of the shaft, the restriction member can be fitted into the fitting part, and when the first end part of the gear is located at the side of the free end of the shaft, a part of the gear prevents the restriction member from being fitted into the fitting part.SELECTED DRAWING: Figure 10

Description

[Technical field]

[0001] The present invention relates to a power transmission device having a shaft and a gear, and a recording device equipped with the same. The present invention also relates to a gear having a shaft hole capable of being fitted onto a shaft. [Background technology]

[0002] The torque transmission device disclosed in Patent Document 1 includes a gear, a rotating shaft on which the gear is provided, and an E-ring that prevents the gear from coming off the rotating shaft. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-145627 A Summary of the Invention [Problem to be solved by the invention]

[0004] When the shape of the gear is asymmetrical in the axial direction of the rotating shaft, an assembly worker may install the gear in the wrong direction. For example, if the gear is installed in the wrong direction, the teeth will be misaligned in the axial direction and will not be able to mesh properly with adjacent gears. In such a case, the gear must be removed and reinstalled, resulting in an extra process. [Means for solving the problem]

[0005] In order to solve the above problem, the power transmission device of the present invention is a power transmission device having a shaft, a gear having an axial hole that fits onto the shaft, and a regulating member that fits into a fitting portion formed on the shaft and regulates movement of the gear toward a free end side of the shaft, wherein the gear has a first end that is the outermost end in the first direction and a second end that is the outermost end in the second direction, with one of the axial directions of the axial hole being a first direction and the other being a second direction, and when the second end of the gear is located on the free end side of the shaft, the regulating member can fit into the fitting portion, and when the first end of the gear is located on the free end side of the shaft, a part of the gear prevents the regulating member from fitting into the fitting portion.

[0006] The recording device of the present invention is also characterized by comprising a recording unit that records on a medium, a pair of transport rollers that transport the medium, a drive source for the pair of transport rollers, and the above-mentioned power transmission device that transmits power from the drive source to the pair of transport rollers.

[0007] The gear of the present invention is a gear having a shaft hole that fits onto a shaft, one of the axial directions of the shaft hole being a first direction and the other being a second direction, the gear having a first end which is the outermost end in the first direction and a second end which is the outermost end in the second direction, the distance along the axial direction from the first end to an opening of the shaft hole in the second direction being a first distance, and the distance along the axial direction from the second end to the opening of the shaft hole in the first direction being a second distance, the first distance being shorter than the second distance, and when the second end is located on the free end side of the shaft, an inner circumferential surface of the shaft hole does not cover the outer circumferential surface of the shaft in a first region in the axial direction of the shaft, and when the first end is located on the free end side of the shaft, the inner circumferential surface of the shaft hole covers the outer circumferential surface of the shaft in the first region in the axial direction of the shaft.

[0008] The gear of the present invention is a gear having a shaft hole that fits onto a shaft, with one axial direction of the shaft hole being a first direction and the other being a second direction, the gear having a first end that is the outermost end in the first direction and a second end that is the outermost end in the second direction, the second end being formed by a protrusion that protrudes in the second direction from an opening of the shaft hole in the second direction, and when the second end is located on the free end side of the shaft, the protrusion covers only a part of the first region in the axial direction of the shaft, and when the first end is located on the free end side of the shaft, the inner surface of the shaft hole covers the first region.

[0009] The gear of the present invention is a gear having a shaft hole that fits onto a shaft, one axial direction of the shaft hole being a first direction and the other being a second direction, the gear having a first end that is the outermost end in the first direction and a second end that is the outermost end in the second direction, the first end being formed by a protruding portion that protrudes in the first direction from an opening of the shaft hole in the first direction, the protruding portion being located radially outward from an outer peripheral surface of the shaft which is a cylindrical surface, when the second end of the gear is located on the free end side of the shaft, a part of the gear does not face the first region in the axial direction of the shaft, and when the first end of the gear is located on the free end side of the shaft, the protruding portion faces the first region in the axial direction of the shaft. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a diagram showing a media transport path of the printer. [Diagram 2] FIG. 2 is an external perspective view of the printer with the first cover and the second cover closed. [Diagram 3] FIG. 2 is an external perspective view of the printer with the first cover closed and the second cover open. [Figure 4] FIG. 4 is a perspective view of a first power transmission device provided on the second cover. [Diagram 5] FIG. 2 is a perspective view of a main portion of the first power transmission device. [Figure 6] FIG. 4 is a perspective view of gears constituting the first power transmission device. [Figure 7] FIG. 4 is a perspective view of gears constituting the first power transmission device. [Figure 8] FIG. 4 is a perspective view of a shaft that constitutes the first power transmission device. [Figure 9] 4 is a cross-sectional view of the first power transmission device with gears fitted to a shaft in the correct orientation. FIG. [Figure 10] 11 is a cross-sectional view of a state in which a gear constituting the first power transmission device is fitted onto a shaft in an incorrect orientation. [Figure 11] A diagram of the E-ring that constitutes the first power transmission device being removed. [Figure 12] FIG. 4 is a perspective view of a second power transmission device provided on the second cover. [Figure 13] FIG. 4 is a perspective view of a gear that constitutes the second power transmission device. [Figure 14] FIG. 4 is a perspective view of a gear that constitutes the second power transmission device. [Figure 15] FIG. 4 is a perspective view of gears and shafts that constitute a second power transmission device. [Figure 16] FIG. 4 is a perspective view of a shaft that constitutes the second power transmission device. [Figure 17] 13 is a cross-sectional view of the second power transmission device with gears fitted to a shaft in the correct orientation. FIG. [Figure 18] 13 is a cross-sectional view of a state in which a gear constituting the second power transmission device is fitted onto a shaft in an incorrect orientation. [Figure 19] FIG. 4 is a perspective view of a gear that constitutes the second power transmission device. [Figure 20] 13 is a cross-sectional view of the second power transmission device with gears fitted to a shaft in the correct orientation. FIG. [Figure 21] 13 is a cross-sectional view of a state in which a gear constituting the second power transmission device is fitted onto a shaft in an incorrect orientation. [Figure 22] FIG. 4 is a perspective view of a gear that constitutes the second power transmission device. [Diagram 23] 13 is a cross-sectional view of the second power transmission device with gears fitted to a shaft in the correct orientation. FIG. [Figure 24] 13 is a cross-sectional view of a state in which a gear constituting the second power transmission device is fitted onto a shaft in an incorrect orientation. [Diagram 25]FIG. 4 is a perspective view of a gear that constitutes the second power transmission device. [Figure 26] 13 is a cross-sectional view of the second power transmission device with gears fitted to a shaft in the correct orientation. FIG. [Figure 27] 13 is a cross-sectional view of a state in which a gear constituting the second power transmission device is fitted onto a shaft in an incorrect orientation. [Figure 28] FIG. 4 is a perspective view of a fixing structure that fixes the cover member to the inner plate. [Figure 29] A diagram of the E-ring removed from the state shown in Figure 19. [Diagram 30] FIG. 4 is a cross-sectional view of a fixing structure that fixes the cover member to the inner plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will now be briefly described. A power transmission device according to a first aspect is a power transmission device having a shaft, a gear having an axial hole that fits onto the shaft, and a regulating member that fits into a fitting portion formed on the shaft and regulates movement of the gear toward the free end side of the shaft, wherein the gear has a first end that is the outermost end in the first direction and a second end that is the outermost end in the second direction, with one of the axial directions of the shaft hole being a first direction and the other being a second direction, and when the second end of the gear is located on the free end side of the shaft, the regulating member can fit into the fitting portion, and when the first end of the gear is located on the free end side of the shaft, a part of the gear prevents the regulating member from fitting into the fitting portion.

[0012] According to this aspect, when the second end of the gear is located on the free end side of the shaft, the regulating member can engage with the engaging portion, and when the first end of the gear is located on the free end side of the shaft, a part of the gear prevents the regulating member from engaging with the engaging portion, thereby preventing the gear from being attached to the shaft in the wrong orientation, i.e., with the first end on the free end side of the shaft.

[0013] A second aspect is an aspect dependent on the first aspect, characterized in that the first end of the gear is formed by a cylindrical portion having the shaft hole on the inside and having an outer diameter smaller than the outer diameter of the gear, the opening of the shaft hole on the second end side is formed at the bottom of a recess that is recessed in the first direction more than the outer periphery, when the second end of the gear is located on the free end side of the shaft, the recess exposes the fitting portion so that the regulating member can fit into the fitting portion, and when the first end of the gear is located on the free end side of the shaft, the cylindrical portion covers at least a portion of the fitting portion, thereby preventing the regulating member from fitting into the fitting portion.

[0014] According to this aspect, when the second end of the gear is located on the free end side of the shaft, the recess exposes the fitting portion, allowing the regulating member to fit into the fitting portion, and when the first end of the gear is located on the free end side of the shaft, the cylindrical portion covers at least a portion of the fitting portion, thereby preventing the regulating member from fitting into the fitting portion, thereby obtaining the effect of the first aspect described above. In addition, by adjusting the axial length of the cylindrical portion, the position of the teeth in the axial direction can be easily adjusted.

[0015] A third aspect is an aspect dependent on the second aspect, characterized in that the gear has an inclined surface on the inside of the recess that faces in the second direction from the center in the radial direction toward the outside.

[0016] When an attempt is made to remove the regulating member from the state in which the regulating member is fitted in the fitting portion, the regulating member may get caught on the inner side of the recess, making it difficult to remove. However, according to the present embodiment, the gear has an inclined surface on the inside of the recess that extends from the center in the radial direction outward toward the second direction, thereby preventing the regulating member from getting caught on the inside of the recess and making it easy to remove the regulating member.

[0017] A fourth aspect is a aspect dependent on the third aspect, characterized in that the regulating member is an E-ring, the fitting portion is a groove into which the E-ring fits, and when the E-ring is removed from the fitting portion, a part of the E-ring is hooked on the groove with the outer periphery of the E-ring resting on the inclined surface.

[0018] When removing the E-ring from the fitting portion, the outer circumference of the E-ring is placed on the inclined surface and part of the E-ring is caught in the groove. If the inclined surface were not formed, the outer circumference of the E-ring would get caught on the inside of the recess and be difficult to remove. However, by forming the inclined surface, the regulating member can be prevented from getting caught on the inside of the recess, and the regulating member can be easily removed.

[0019] A fifth aspect is an aspect dependent on the first aspect, wherein a first distance is a distance along the axial direction from the first end to the opening of the shaft hole in the second direction, and a second distance is a distance along the axial direction from the second end to the opening of the shaft hole in the first direction, the second distance being longer than the first distance, and when the second end of the gear is located on the free end side of the shaft, the fitting portion is exposed so that the regulating member can fit into the fitting portion, and when the first end of the gear is located on the free end side of the shaft, the inner surface of the shaft hole covers at least a portion of the fitting portion, thereby preventing the regulating member from fitting into the fitting portion.

[0020] According to this aspect, when the second end of the gear is located on the free end side of the shaft, the fitting portion is exposed, allowing the regulating member to fit into the fitting portion, and when the first end of the gear is located on the free end side of the shaft, the inner surface of the shaft hole covers at least a portion of the fitting portion, thereby preventing the regulating member from fitting into the fitting portion, thereby obtaining the effect of the first aspect described above.

[0021] A sixth aspect is an aspect dependent on the first aspect, characterized in that the second end of the gear is formed by a protrusion protruding in the second direction from the second direction opening of the shaft hole, and when the second end of the gear is located on the free end side of the shaft, the regulating member can be fitted to a portion of the fitting portion except for a portion covered by the protrusion, and when the first end of the gear is located on the free end side of the shaft, the inner surface of the shaft hole covers the fitting portion, thereby preventing the regulating member from fitting to the fitting portion.

[0022] According to this aspect, when the second end of the gear is located on the free end side of the shaft, the regulating member can engage with the fitting portion except for the portion covered by the protrusion, and when the first end of the gear is located on the free end side of the shaft, the inner surface of the shaft hole covers the fitting portion, thereby preventing the regulating member from engaging with the fitting portion, thereby obtaining the effect of the first aspect described above.

[0023] The seventh aspect is a dependent aspect of the sixth aspect, characterized in that the portion of the shaft into which the shaft hole fits is formed in a D-cut shape having an arc portion and a straight portion along the outer periphery, and the shaft hole is shaped to fit with the D-cut shape over the entire axial direction.

[0024] In the case where the portion of the shaft where the shaft hole fits is formed in a D-cut shape having an arc portion and a straight portion along the outer periphery, one side of the shaft hole in the axial direction can be formed so as not to fit with the D-cut shape to prevent the gear from being attached in the wrong orientation. However, in this case, since the D-cut shape fits only in a part of the shaft hole in the axial direction, a rotational torque is applied locally, which may cause damage to the shaft hole. However, according to this aspect, the projection prevents the gear from being attached in the wrong direction, and the shaft hole can be formed to have a shape that fits with the D-cut shape over the entire axial direction, thereby preventing damage to the shaft hole.

[0025] The eighth aspect is a aspect dependent on the seventh aspect, characterized in that the regulating member is an E-ring, the fitting portion is a groove into which the E-ring fits, and the protrusion portion is provided at a position corresponding to the straight portion when the shaft hole is fitted onto the shaft, and at a position corresponding to the opening of the E-ring when the E-ring is fitted into the groove.

[0026] According to the present aspect, the protrusion is provided at a position which corresponds to the straight portion when the shaft hole is fitted onto the shaft, and at a position which corresponds to the opening of the E-ring when the E-ring is fitted into the groove, thereby preventing the protrusion from getting in the way when the E-ring is fitted into the groove.

[0027] A ninth aspect is an aspect dependent on the eighth aspect, and is characterized in that the gear is a first gear and has a second gear that meshes with the first gear, the first gear is movable between a position where it meshes with the second gear and a position where it is separated from the second gear, and when the first gear moves from the position where it is separated from the second gear to the position where it meshes with the second gear, the teeth of the first gear enter the tooth grooves of the second gear from a corner portion, and the corner portion is chamfered or rounded.

[0028] When the first gear moves from the second position to the first position, in a configuration in which the teeth of the first gear enter the tooth grooves of the second gear through a corner, there is a risk that the corner will collide with the teeth of the second gear. However, according to the present aspect, the corner is chamfered or rounded, which prevents the corner from colliding with the teeth of the second gear.

[0029] A tenth aspect is an aspect dependent on the first aspect, characterized in that the first end of the gear is formed by a protrusion protruding in the first direction from the first direction opening of the shaft hole, the protrusion is located radially outward from the outer circumferential surface of the shaft which is a cylindrical surface, when the second end of the gear is located on the free end side of the shaft, the fitting portion is exposed to an extent that the regulating member can fit into the fitting portion, so that the regulating member can fit into the fitting portion, and when the first end of the gear is located on the free end side of the shaft, the protrusion is in a position that interferes with the regulating member, so that the protrusion prevents the regulating member from fitting into the fitting portion.

[0030] According to this aspect, when the second end of the gear is located on the free end side of the shaft, the fitting portion is exposed to an extent that the regulating member can fit into the fitting portion, thereby enabling the regulating member to fit into the fitting portion, and when the first end of the gear is located on the free end side of the shaft, the protrusion is in a position that interferes with the regulating member, thereby preventing the regulating member from fitting into the fitting portion, thereby obtaining the effect of the first aspect described above.

[0031] The recording device of the 11th aspect is characterized in that it comprises a recording unit that records on a medium, a pair of transport rollers that transport the medium, a drive source for the pair of transport rollers, and the power transmission device of any of the first to tenth aspects that transmits power from the drive source to the pair of transport rollers. According to this aspect, the recording device can achieve the effects of any one of the first to tenth aspects described above.

[0032] A gear according to a twelfth aspect is a gear having a shaft hole that fits onto a shaft, one of the axial directions of the shaft hole being a first direction and the other being a second direction, the gear having a first end that is the outermost end in the first direction and a second end that is the outermost end in the second direction, the first distance being a distance along the axial direction from the first end to an opening of the shaft hole in the second direction and the second distance being a distance along the axial direction from the second end to the opening of the shaft hole in the first direction, the first distance being shorter than the second distance, and when the second end is located on the free end side of the shaft, the inner circumferential surface of the shaft hole does not cover the outer circumferential surface of the shaft in a first region in the axial direction of the shaft, and when the first end is located on the free end side of the shaft, the inner circumferential surface of the shaft hole covers the outer circumferential surface of the shaft in the first region in the axial direction of the shaft.

[0033] According to this aspect, when the second end is located on the free end side of the shaft, the inner surface of the shaft hole does not cover the outer surface of the shaft in a first region in the axial direction of the shaft, and therefore, the first region can be used to restrict movement of the gear toward the free end side of the shaft. Furthermore, when the first end is located on the free end side of the shaft, the inner surface of the shaft hole covers the outer surface of the shaft in the first region in the axial direction of the shaft, thereby preventing restriction of movement of the gear using the first region, and ultimately preventing the first end from being attached to the shaft in an orientation that faces the free end side of the shaft.

[0034] A gear according to a thirteenth aspect is a gear having a shaft hole that fits onto a shaft, with one axial direction of the shaft hole being a first direction and the other being a second direction, and having a first end that is the outermost end in the first direction and a second end that is the outermost end in the second direction, wherein the second end is formed by a protrusion that protrudes in the second direction from an opening of the shaft hole in the second direction, and when the second end is on the free end side of the shaft, in a first region in the axial direction of the shaft, the protrusion covers only a part of the first region, and when the first end is on the free end side of the shaft, the inner surface of the shaft hole covers the first region.

[0035] According to this aspect, when the second end is located on the free end side of the shaft, the protrusion covers only a portion of a first region in the axial direction of the shaft, and therefore, the first region can be utilized to restrict movement of the gear toward the free end side of the shaft. Furthermore, when the first end is located on the free end side of the shaft, the inner surface of the shaft hole covers the first region, thereby preventing restriction of movement of the gear using the first region, and thus preventing the first end from being attached to the shaft in an orientation that faces the free end side of the shaft.

[0036] A gear according to a fourteenth aspect is a gear having a shaft hole that fits onto a shaft, with one axial direction of the shaft hole being a first direction and the other being a second direction, the gear having a first end that is the outermost end in the first direction and a second end that is the outermost end in the second direction, the first end being formed by a protruding portion that protrudes in the first direction from an opening of the shaft hole in the first direction, the protruding portion being located radially outward from the outer peripheral surface of the shaft which is a cylindrical surface, when the second end of the gear is located on the free end side of the shaft, a part of the gear does not face the first region in the axial direction of the shaft, and when the first end of the gear is located on the free end side of the shaft, the protruding portion faces the first region in the axial direction of the shaft.

[0037] According to this aspect, when the second end of the gear is located on the free end side of the shaft, a part of the gear does not face the first region in the axial direction of the shaft, and therefore, the first region can be utilized to restrict movement of the gear toward the free end side of the shaft. Furthermore, when the first end of the gear is located on the free end side of the shaft, the protrusion faces the first region in the first region in the axial direction of the shaft, thereby preventing restriction of movement of the gear using the first region, and ultimately preventing the first end from being attached to the shaft in an orientation that faces the free end side of the shaft.

[0038] The present invention will be specifically described below. In the following, an inkjet printer 1 that performs recording by ejecting ink, which is an example of a liquid, onto a medium such as recording paper will be described as an example of a recording device. In the following, the inkjet printer 1 will be abbreviated to printer 1. From the perspective of transporting the medium, the configuration of the printer 1 excluding the line head 44 described below can be considered as the medium transport device 100. The printer 1 is equipped with the medium transport device 100, the line head 44, and a power transmission device described below. The medium transport device 100 also includes a power transmission device described below. The power transmission device here refers to at least one of a first power transmission device 60 and a second power transmission device 70 described below.

[0039] The XYZ coordinate system shown in each figure is an orthogonal coordinate system, with the Y-axis direction being the direction that intersects with the medium transport direction, i.e., the medium width direction, and also the device depth direction. The +Y direction of the Y-axis direction is the direction from the front of the device to the rear of the device, and the -Y direction is the direction from the rear of the device to the front of the device. In this embodiment, a tilt panel 8 (see Figures 2 and 3) that constitutes an operation unit for performing various operation settings is provided on the front of the device, and the side of the device on which the tilt panel 8 is provided is the front of the device. In addition, since the second cover 52 described later opens and closes, when illustrating the configuration provided on the second cover 52, the coordinate system is omitted.

[0040] The X-axis direction is the width direction of the device, and as seen by an operator facing the tilt panel 8, the +X direction is the left direction and the -X direction is the right direction. The Z-axis direction is the vertical direction and is the normal direction to the mounting surface G of the printer 1, that is, the height direction of the device. Within the Z-axis direction, the +Z direction is the upward direction and the -Z direction is the downward direction. In the following, the direction in which the medium is transported may be referred to as "downstream," and the opposite direction may be referred to as "upstream." In addition, the medium transport path is shown by a dashed line in Figure 1. In the printer 1, the medium is transported through the medium transport path shown by the dashed line in Figure 1.

[0041] The F-axis direction is the medium transport direction between a line head 44 and the transport belt 13 (described later), i.e., in the recording area, with the +F direction being the downstream transport direction and the opposite -F direction being the upstream transport direction. The V-axis direction is perpendicular to the F-axis direction.

[0042] The printer 1 is configured so that an add-on unit (not shown) can be connected to the bottom of the housing 2, and is configured so that media can be fed from this add-on unit. In Fig. 1, reference numeral 28 denotes a pair of transport rollers that feed the media fed from the add-on unit (not shown) into the housing 2. The printer 1 may be configured as a multifunction machine equipped with a scanner unit (not shown) that is an example of an image reading device on the upper part of the housing 2. The housing 2 can also be called the device main body 2.

[0043] The housing 2 has a first media cassette 3 that stores media in its lower portion. A pick roller 21 that sends out the stored media in the -X direction is provided for the first media cassette 3. The medium sent out by the pick roller 21 is sent toward the transport roller pair 31 by the feed roller pair 25. In the following, unless otherwise specified, a "roller pair" is defined as consisting of a drive roller that is driven by a drive source (not shown) to apply a feeding force to the medium, and a driven roller that rotates in contact with the drive roller or the medium. The supply roller 19 and the separation roller 20 provided near the transport roller pair 38 are a roller pair that feeds the medium from a supply tray not shown in FIG.

[0044] The medium receiving the feeding force from the transport roller pair 31 is sent between the line head 44, which is an example of a recording unit, and the transport belt 13, that is, to a position facing the line head 44. Note that hereinafter, the medium transport path from the transport roller pair 31 to the transport roller pair 32 is referred to as the transport path T1 during recording. The line head 44 constitutes the head unit 43. The line head 44 performs recording by ejecting ink onto the surface of the medium. The line head 44 is an ink ejection head configured so that the nozzles that eject ink cover the entire area in the width direction of the medium, and is configured as an ink ejection head that can perform recording over the entire width of the medium without moving in the width direction of the medium. However, the ink ejection head is not limited to this, and may be a type that is mounted on a carriage and ejects ink while moving in the width direction of the medium.

[0045] The head unit 43 is provided so as to be capable of moving forward and backward relative to the transport path T1 during recording, and is provided so as to be movable between a recording position where it advances onto the transport path T1 during recording to record on the medium, and a retreat position where it retreats from the transport path T1 during recording. FIG. 1 shows a state in which the head unit 43 is in the recording position, and in this state recording is performed on the medium.

[0046] Reference numerals 10A, 10B, 10C, and 10D denote ink storage units serving as liquid storage units. Ink ejected from the line head 44 is supplied from each ink storage unit to the line head 44 via a tube (not shown). The ink storage units 10A, 10B, 10C, and 10D are detachably provided in the mounting units 11A, 11B, 11C, and 11D, respectively. Reference numeral 12 denotes a waste liquid storage section that stores ink as waste liquid discharged from the line head 44 toward a flushing cap (not shown) for maintenance purposes.

[0047] The conveyor belt 13 is an endless belt that is wound around pulleys 14 and 15, and rotates when at least one of the pulleys 14 and 15 is driven by a motor (not shown). The medium is conveyed to a position facing the line head 44 while being attracted to the belt surface of the conveyor belt 13. The medium can be attracted to the conveyor belt 13 by a known attraction method such as an air suction method or an electrostatic attraction method.

[0048] Here, the transport path T1 during recording, which passes through a position facing the line head 44, intersects both the horizontal and vertical directions and transports the medium upward. That is, the F-axis direction intersects both the horizontal and vertical directions. Therefore, the ejection surface 44a of the line head 44 that ejects ink is also parallel to the F-axis direction and intersects both the horizontal and vertical directions. In this embodiment, the angle α that the F-axis direction makes with the horizontal direction is 75°. The angle α may be changed to another angle within the range of 0°<α≦90°. For example, the angle α may be set to the range of 45°≦α≦80°. When making the printer 1 compact, 60°≦α≦80° is preferable.

[0049] The medium on whose first side recording has been performed by the line head 44 is then conveyed further upward by the conveyor roller pair 32 positioned downstream of the conveyor belt 13 . A flap 41 is provided downstream of the transport roller pair 32, and the transport direction of the medium is switched by this flap 41. When the medium is sent to a post-processing unit 90 described below, the medium is sent to an upper discharge path T5 by the flap 41. The medium sent to the discharge path T5 is sent to the post-processing unit 90 by the transport roller pair 35A and the downstream transport roller pair 35B.

[0050] When recording is performed on the second side of the medium in addition to the first side, the transport direction of the medium is directed to branch position K1 by flap 41. The medium then passes through branch position K1 and enters switchback path T2. In this embodiment, switchback path T2 is the medium transport path above branch position K1. Switchback path T2 is an example of a transport path that is provided inside housing 2 and transports the medium along a transport direction that includes the +Z direction and the -Z direction. Incidentally, the transport direction including the +Z direction and the opposite -Z direction does not need to be strictly parallel to the +Z direction and the -Z direction, but may include a +Z direction component or a -Z direction component. The switchback path T2 has a curved path portion T2a, and the medium is curved in the curved path portion T2a.

[0051] Switchback path T2 is provided with a pair of transport rollers 36, 37. The medium that enters switchback path T2 is transported upward by the pair of transport rollers 36, 37, and when the lower end of the medium passes branch position K1, the rotation direction of the pair of transport rollers 36, 37 is switched, whereby the medium is transported downward.

[0052] A connection path T3 is connected to the switchback path T2. In this embodiment, the connection path T3 is a medium transport path that extends from the branch position K1 to the transport roller pair 34. A reversing path T4 is connected to the connection path T3. In this embodiment, the reversing path T4 is a medium transport path that extends from the transport roller pair 34 to the transport roller pair 31 through the transport roller pair 38. The reversing path T4 is a transport path upstream of a position facing the line head 44 and is located vertically below the line head 44. The reversing path T4 is a path portion that is convex vertically downward and curves the medium upward to reverse it. The medium conveyed downward from branch position K1 receives a feeding force from conveying roller pairs 33 and 34, reaches conveying roller pair 38, is turned over, and is sent to conveying roller pair 31.

[0053] The medium is again sent to a position facing the line head 44, with the second side opposite the first side on which recording has already been performed facing the line head 44. This makes it possible for the line head 44 to record on the second side of the medium.

[0054] The upper part of the switchback path T2 described above can be exposed by opening the first cover 51, which allows for jam clearance work to be performed. In addition, the lower part of the switchback path T2 can be exposed by opening the second cover 52, which allows jam clearance work to be performed. In addition, a part of the discharge path T5 can be exposed by opening the inner door 53, which allows the jamming clearance work to be performed. In this specification, the jam clearing operation means the operation of removing the jammed medium.

[0055] Next, the medium transported along the discharge path T5 is discharged to the internal discharge section 7. The internal discharge section 7 is an internal space provided in the printer 1 for discharging the medium after recording, and is a space that is open in the -Y and +X directions. The internal discharge section 7 overlaps with the top surface of the housing 2 when viewed from the +Z direction. A post-processing unit 90 is provided in this internal discharge section 7. The post-processing unit 90 may be detachable from the internal discharge section 7. In addition, when the post-processing unit 90 is not attached, a discharge tray (not shown) may be configured to be attachable instead of the post-processing unit 90.

[0056] The post-processing unit 90 has a processing tray 91, and media discharged through the discharge path T5 are temporarily stacked on the processing tray 91. The media stacked on the processing tray 91 can be stapled by a post-processing section 92. The stapled media are discharged toward and stacked on a stacking tray 93 by a discharge means (not shown). In addition, binding processing using a stapler is an example of post-processing, and post-processing is not limited to binding processing, but may be other processes such as a punching process in which holes are punched in the medium, a saddle stitching process in which a stack of media is saddle stitched, and a shift discharge process in which the discharge position of the stack of media is shifted alternately in the media width direction and discharged.

[0057] Next, the first cover 51 and the second cover 52 will be described. As shown in FIGS. 2 and 3, the printer 1 has a first cover 51 on the right side, and also has a second cover 52 below the first cover 51.

[0058] The first cover 51 is a cover that can rotate around a rotation shaft 51a (see FIG. 1). In this embodiment, the axis of the rotation shaft 51a is parallel to the Y-axis. The first cover 51 can rotate between an open state (not shown) in which a part of the switchback path T2 is exposed, and a closed state (FIG. 2) in which the part is not exposed. The rotation shaft 51a of the first cover 51 is provided near the end of the first cover 51 in the -Z direction, so that the end of the first cover 51 in the +Z direction is the free end when rotating. A grip portion 51c is provided near the end portion in the +Z direction of the first cover 51, and the first cover 51 can be opened by inserting fingers into the grip portion 51c.

[0059] The second cover 52 is a cover that can rotate via a hinge portion 52a, and is disposed in the -Z direction with respect to the first cover 51. In this embodiment, the axial center line of the hinge portion 52a, i.e., the axial center line of the rotation of the second cover 52, is parallel to the Z axis. The second cover 52 is rotatable between an open state (FIG. 3) in which a portion of the switchback path T2 is exposed, and a closed state (FIG. 2) in which the portion is not exposed. The hinge portion 52a of the second cover 52 is provided near the end of the second cover 52 in the +Y direction, so that the end of the second cover 52 in the -Y direction is the free end when rotating. A grip portion 52c is provided near the end portion in the -Y direction of the second cover 52, and the second cover 52 can be opened by inserting fingers into the grip portion 52c.

[0060] When the first cover 51 is opened, the upper part of the switchback path T2, particularly the curved path portion T2a (FIG. 1), is exposed. This makes it possible to carry out a jamming operation when a jam occurs in the upper part of the switchback path T2. When the second cover 52 is opened, the lower part of the switchback path T2 is exposed. This allows the jamming process to be cleared if a jam occurs at the lower part of the switchback path T2. When the second cover 52 is opened, the nip between the transport roller pairs 36 and 37 is released.

[0061] As shown in Fig. 3, an inner door 53 is provided inside the second cover 52. The inner door 53 is an opening / closing body that can rotate around a rotation shaft 53a (Fig. 1). The inner door 53 can rotate between an open state (Fig. 1) in which a part of the discharge path T5 is exposed, and a closed state (Fig. 3) in which the part is not exposed. The rotation shaft 53a of the inner door 53 is provided near the end of the inner door 53 in the +Y direction, so that the end of the inner door 53 in the -Y direction is the free end when rotating. The middle door 53 forms a part of the switchback path T2 and also forms a part of the discharge path T5. When the middle door 53 is opened, a part of the discharge path T5 is exposed. This makes it possible to carry out a jam clearance operation when a jam occurs in the discharge path T5.

[0062] Next, the first power transmission device 60 provided on the second cover 52 will be described. The first power transmission device 60 is a power transmission device provided in the second cover 52 in the area A shown in Fig. 3. The first power transmission device 60 is a device for receiving power from a motor (not shown) provided on the device main body side in order to drive the transport roller pairs 36 and 37 shown in Fig. 1. A gear 59 shown in Fig. 3 is a gear for transmitting power from the device main body side to the first power transmission device 60.

[0063] The first power transmission device 60 includes a gear 61 as shown in Fig. 4. When the second cover 52 is closed, the gear 61 meshes with the gear 59 shown in Fig. 3. When the second cover 52 is opened, the gear 61 moves away from the gear 59. Gear 61 meshes with gear 62. Gear 62 is a double gear in which a large gear and a small gear are integrally formed, and the small gear constituting gear 62 meshes with gears 63 and 64 as shown in FIG. The gear 63 rotates around a shaft 65. The movement of the gear 63 toward the free end of the shaft 65 is restricted by an E-ring 67. The gear 63 may rotate relatively to the shaft 65, or may rotate integrally with the shaft 65. The gear 64 rotates around a shaft 66. The movement of the gear 64 toward the free end of the shaft 66 is restricted by an E-ring 67. The gear 64 may rotate relatively to the shaft 66, or may rotate integrally with the shaft 66.

[0064] Gear 63 and gear 64 have the same structure, and the structure of gear 63 will be described below with reference to FIGS. The gear 63 is a spur gear having teeth 63m on its outer periphery. The gear 63 has a shaft hole 63a into which a shaft 65 is fitted. 6, 7, 9, and 10, the symbol D1 indicates a first direction, and the symbol D2 indicates a second direction. The first direction D1 and the second direction D2 are directions to show the structure of the gear 63. The first direction D1 and the second direction D2 are directions along the axial center line of the shaft 65 and the shaft hole 63a.

[0065] In Fig. 6, reference symbol 63b indicates the inner peripheral surface of the shaft hole 63a. Also in Fig. 6, reference symbol 63c indicates the opening of the shaft hole 63a in the second direction D2. Also in Fig. 6, reference symbol 63j indicates a second end portion. The second end portion 63j is the outermost end portion of the gear 63 in the second direction D2. The second end 63j is formed along the outer periphery of the gear 63, and a recess 63d is formed so as to recess from the outer periphery toward the center. It can be said that the opening 63c is formed at the bottom of the recess 63d.

[0066] A plurality of ribs 63e are formed radially from the opening 63c. The tops of the ribs 63e form the bottom surface of the recess 63d. The ribs 63e are connected to an inclined surface 63f, which is further connected to a chamfered portion 63g. The chamfered portion 63g is formed along the circumferential direction on the inside of the second end portion 63j.

[0067] Next, a cylindrical portion 63k is formed in the first direction D1 of the gear 63 as shown in Fig. 7. The shaft hole 63a is formed inside the cylindrical portion 63k. In Fig. 7, reference symbol 63n is an opening of the shaft hole 63a in the first direction D1. Also in Fig. 7, reference symbol 63h is a first end portion. The first end portion 63h is the outermost end portion of the gear 63 in the first direction D1. The first end portion 63h is formed by an end surface of the cylindrical portion 63k in the first direction D1.

[0068] The shaft 65 is provided on a frame 68 as shown in Fig. 8. Reference numeral 65a denotes a base end of the shaft 65, and reference numeral 65b denotes a free end of the shaft 65. A groove 65c, which is an example of a fitting portion, is formed in a position close to the free end 65b of the shaft 65. The groove 65c is formed around the entire outer periphery of the shaft 65. In the axial direction of the shaft 65, the region where the groove 65c is formed is an example of a first region. Therefore, the groove 65c may be referred to as the first region 65c.

[0069] 9 shows the gear 63 fitted to the shaft 65 in the correct orientation. The symbol a1 denotes the distance along the axial direction from the first end 63h to the opening 63c in the second direction D2, which will be referred to as the first distance a1 below. The symbol a2 denotes the distance along the axial direction from the second end 63j to the opening 63n in the first direction D1, which will be referred to as the second distance a2 below. The second distance a2 is longer than the first distance a1. 9 shows a state in which the first end 63h is in contact with the frame 68. As shown in FIG.

[0070] 9, when the gear 63 is fitted to the shaft 65 so that the second end 63j is on the free end 65b side of the shaft 65, a groove 65c, which is an example of a fitting portion, is exposed above the opening 63c. This allows the E-ring 67 to fit into the groove 65c. 10, when the gear 63 is fitted onto the shaft 65 so that the first end 63h faces the free end 65b of the shaft 65, the inner peripheral surface 63b of the shaft hole 63a covers the groove 65c. Therefore, in this state, the E-ring 67 cannot be fitted into the groove 65c.

[0071] In this manner, when the gear 63 is fitted onto the shaft 65 so that the first end 63h is on the free end 65b side of the shaft 65, a part of the gear 63, specifically the inner surface 63b of the shaft hole 63a, prevents the gear 63 from fitting into the groove 65c of the E-ring 67, thereby preventing the gear 63 from being attached to the shaft 65 in the wrong orientation, i.e., with the first end 63h on the free end 65b side of the shaft 65.

[0072] Furthermore, when the gear 63 is fitted onto the shaft 65 so that the second end 63j is on the side of the free end 65b of the shaft 65, the inner surface 63b of the shaft hole 63a does not cover the first region in which the groove 65c is formed in the axial direction of the shaft 65, and when the gear 63 is fitted onto the shaft 65 so that the first end 63h is on the side of the free end 65b of the shaft 65, it can be said that the gear 63 has a configuration in which the inner surface 63b of the shaft hole 63a covers the first region.

[0073] When the second end 63j is located on the free end 65b side of the shaft 65, the E-ring 67 can fit into the groove 65c, and when the first end 63h is located on the free end 65b side of the shaft 65, a part of the gear 63 prevents the E-ring 67 from fitting into the groove 65c. This configuration can be realized as follows. For example, as in this embodiment, the first end 63h is formed of a cylindrical portion 63k having an axial hole 63a on the inside and having an outer diameter smaller than the outer diameter of the gear 63, and the opening 63c of the axial hole 63a on the second end 63j side is formed at the bottom of a recess 63d recessed in the first direction D1. As a result, when the second end 63j of the gear 63 is located on the free end 65b side of the shaft 65, the recess 63d exposes the groove 65c, so that the E-ring 67 can fit into the groove 65c. When the first end 65h of the gear 63 is located on the free end 65b side of the shaft 65, the cylindrical portion 63k covers at least a part of the groove 65c, preventing the E-ring 67 from fitting into the groove 65c. In this embodiment, the cylindrical portion 63k covers the entire groove 65c, but even if the cylindrical portion 63k covers a part of the groove 65c, it is sufficient that the E-ring 67 is prevented from fitting into the groove 65c. According to this configuration, the position of the teeth 63m in the axial direction can be easily adjusted by adjusting the axial length of the cylindrical portion 63k.

[0074] The shape of the outer periphery of the cylindrical portion 63k is not limited to a perfect circle, but may be a polygon. Alternatively, the outer periphery of the cylindrical portion 63k may be a gear, in which case the teeth 63m and the teeth on the outer periphery of the cylindrical portion 63k form a compound gear.

[0075] Also, for example, as in this embodiment, the second distance a2 is made longer than the first distance a1. As a result, when the second end 63j is located on the free end 65b side of the shaft 65, the groove 65c is exposed, and the E-ring 67 can fit into the groove 65c. When the first end 63h is located on the free end 65b side of the shaft 65, the inner circumferential surface 63b of the shaft hole 63a covers at least a part of the groove 65c, preventing the E-ring 67 from fitting into the groove 65c. In this embodiment, the inner circumferential surface 63b of the shaft hole 63a covers the entire groove 65c, but even if the inner circumferential surface 63b covers a part of the groove 65c, it is sufficient that the E-ring 67 is prevented from fitting into the groove 65c.

[0076] Furthermore, when the second end 63j is located toward the free end 65b of the shaft 65, the E-ring 67 can fit into the groove 65c, and when the first end 63h is located toward the free end 65b of the shaft 65, a part of the gear 63 prevents the E-ring 67 from fitting into the groove 65c. This configuration is not limited to the above and may be other configurations.

[0077] The restricting member for restricting the movement of the gear 63 toward the free end 65b of the shaft 65 is not limited to the E-ring 67, and may be another member. For example, a hole may be provided in the shaft 65, and a pin-shaped member that fits into the hole may be used as the restricting member.

[0078] In this embodiment, the gear 63 has an inclined surface 63f that extends from the center in the radial direction outward toward the second direction D2, as described with reference to Fig. 6. This provides the following advantageous effects. When attempting to remove the E-ring 67 from the state in which the E-ring 67 is fitted in the groove 65c of the shaft 65, the E-ring 67 may get caught on the inside of the recess 63d, making it difficult to remove. However, according to this embodiment, since the inclined surface 63f extends from the center in the radial direction outward toward the second direction D2, it is possible to prevent the E-ring 67 from getting caught inside the recess 63d as shown in FIG. 11, and the E-ring 67 can be easily removed. Furthermore, in this embodiment, the inclined surface 63f is connected to the chamfered portion 63g, and the chamfered portion 63g is formed along the circumferential direction on the inside of the second end portion 63j, thereby further reducing the risk of the E-ring 67 getting caught when being removed.

[0079] In this embodiment, the regulating member is E-ring 67, the fitting portion into which the regulating member fits is groove 65c into which E-ring 67 fits, and when E-ring 67 is removed from groove 65c, the outer periphery of E-ring rests on inclined surface 63f, and a part of E-ring 67 hangs on groove 65c. This is clear from the contents of Fig. 11. In this embodiment, the diameter of gear 63 and the diameter of E-ring 67 form such a relationship. In this configuration, if the inclined surface 63f were not formed, the outer periphery of the E-ring 67 would get caught on the inside of the recess 63d, making it difficult to remove; however, by forming the inclined surface 63f as described above, the E-ring 67 can be prevented from getting caught on the inside of the recess 63d, and the E-ring 67 can be easily removed.

[0080] Next, the second power transmission device 70 provided in the second cover 52 will be described. The second power transmission device 70 is a power transmission device provided in the second cover 52 in area B shown in Fig. 3. The second power transmission device 70 is a device for receiving power from a motor (not shown) provided on the device main body side in order to drive the transport roller pairs 33, 34 and the like shown in Fig. 1. A gear 71 shown in Fig. 12 is a gear that transmits power from the device main body side to the second power transmission device 70, and is an example of a second gear.

[0081] The second power transmission device 70 includes a gear 72 that is an example of a first gear. When the second cover 52 is closed, the gear 72 meshes with the gear 71. When the second cover 52 is opened, the gear 72 moves away from the gear 71. In Fig. 12, the arrow Ra indicates the path of movement of the gear 72 when the second cover 52 is closed from the open state. 15, gear 72 rotates around shaft 73. In this embodiment, gear 72 rotates integrally with shaft 73 due to a D-cut structure described later, but it may be configured to rotate relatively to shaft 73. The movement of the gear 72 toward the free end of the shaft 73 is restricted by an E-ring 74 .

[0082] 13 and 14, gear 72 is a spur gear and has teeth 72m on its outer periphery. Gear 72 has a shaft hole 72a that fits onto shaft 73. A first direction D1 and a second direction D2 are directions showing the structure of gear 72 and are directions along the axial center lines of shaft 73 and shaft hole 72a.

[0083] The shaft hole 72a has a D-cut shape when viewed from the axial direction, so that an inner circumferential surface 72b of the shaft hole 72a has a circular arc portion 72b1 and a straight portion 72b2. In Fig. 13, reference symbol 72c denotes an opening of the shaft hole 72a in the second direction D2. Reference symbol 72j denotes a second end. The second end 72j is the outermost end of the gear 72 in the second direction D2. In this embodiment, the second end 72j is formed by a protruding portion 72s that protrudes in the second direction D2. The protruding portion 72s is formed so as to protrude in the second direction D2 from the straight portion 72b2 at the opening 72c.

[0084] In Fig. 14, reference symbol 72n denotes an opening of the shaft hole 72a in the first direction D1. As is clear from Fig. 13 and Fig. 14, the D-cut shape of the shaft hole 72a extends over the entire area in the axial direction.

[0085] 15 and 16, reference numeral 73b denotes a free end of the shaft 73. The tip of the shaft 73 is formed in a D-cut shape, and has an arcuate portion 73e and a straight portion 73d. A groove 73c, which is an example of a fitting portion, is formed in a position close to the free end 73b of the shaft 73. The groove 73c is formed around at least the entire circumference of the arc portion 73e. In the axial direction of the shaft 73, the region in which the groove 73c is formed is an example of a first region. Therefore, the groove 73c may be referred to as the first region 73c. A stopper portion 73f is formed on the straight portion 73d on the side farther from the free end 73b. The stopper portion 73f restricts the movement of the gear 72 in the direction away from the free end 73b.

[0086] 17 shows the gear 72 fitted to the shaft 73 in the correct orientation. The symbol a1 denotes a first distance along the axial direction from the first end 72h to the opening 72c in the second direction D2. The symbol a2 denotes a second distance along the axial direction from the second end 72j to the opening 72n in the first direction D1. The second distance a2 is longer than the first distance a1. FIG. 17 shows a state in which the opening 72n of the shaft hole 72a in the first direction D1 is in contact with the stopper portion 73f.

[0087] As shown in Fig. 17, when the gear 72 is fitted to the shaft 73 so that the second end 72j is on the free end 73b side of the shaft 73, a groove 73c, which is an example of a fitting portion, is exposed above the opening 72c. This allows the E-ring 74 to fit into the groove 73c. ​​As shown in Fig. 15, the width of the protrusion 72s forming the second end 72j is smaller than the width of the opening of the E-ring 74, so that the protrusion 72s does not get in the way when the E-ring 74 fits into the groove 73c.

[0088] 18, when the gear 72 is fitted onto the shaft 73 so that the first end 72h faces the free end 73b of the shaft 73, the inner circumferential surface 72b of the shaft hole 72a covers the groove 73c. ​​Therefore, in this state, the E-ring 74 cannot be fitted into the groove 73c. FIG. 18 shows a state in which the protruding portion 72s, ie, the second end portion 72j, is in contact with the stopper portion 73f.

[0089] In this manner, when the gear 72 is fitted onto the shaft 73 so that the first end 72h is on the free end 73b side of the shaft 73, a part of the gear 72, specifically the inner surface 72b of the shaft hole 72a, prevents the gear 72 from fitting into the groove 73c of the E-ring 74, thereby preventing the gear 72 from being attached to the shaft 73 in the wrong orientation, i.e., with the first end 72h on the free end 73b side of the shaft 73. In this embodiment, the gear 72 is fitted to the shaft 73 having the stopper portion 73f. However, the gear 72 may be fitted to a shaft provided on a frame like the shaft 65 described with reference to FIG. 8, so that the movement of the gear 72 toward the base end side is restricted by the frame.

[0090] Furthermore, when the gear 72 is fitted onto the shaft 73 so that the second end 72j is on the side of the free end 73b of the shaft 73, the protrusion 72s covers only a portion of the first region in which a groove 73c is formed in the axial direction of the shaft 73, and when the gear 72 is fitted onto the shaft 73 so that the first end 72h is on the side of the free end 73b of the shaft 73, the inner surface 72b of the shaft hole 72a covers the first region.

[0091] When the second end 72j is located toward the free end 73b of the shaft 73, the E-ring 74 can fit into the groove 73c, and when the first end 72h is located toward the free end 73b of the shaft 73, a configuration in which a part of the gear 72 prevents the E-ring 74 from fitting into the groove 73c can be achieved by forming the second end 72j of the gear 72 as a protrusion 72s that protrudes in the second direction D2 from the opening 72c in the second direction D2 of the shaft hole 72a, as in this embodiment.

[0092] Furthermore, when the second end 72j is located toward the free end 73b of the shaft 73, the E-ring 74 can fit into the groove 73c, and when the first end 72h is located toward the free end 73b of the shaft 73, a part of the gear 72 prevents the E-ring 74 from fitting into the groove 73c. ​​This configuration is not limited to the above, and may be other configurations.

[0093] In this embodiment, the portion of shaft 73 into which shaft hole 72a fits is formed in a D-cut shape having an arc portion 73e and a straight portion 73d along the outer periphery, and shaft hole 72a is shaped to fit into the D-cut shape over the entire axial direction. In the case where the portion of the shaft 73 into which the shaft hole 72a fits is formed in a D-cut shape having an arc portion 73e and a straight portion 73d along the outer periphery, it is possible to prevent the gear 72 from being attached in the wrong orientation by forming one side of the shaft hole 72a in the axial direction so as not to fit with the D-cut shape. However, in this case, since the D-cut shape fits only in a part of the shaft hole 72a in the axial direction, a rotational torque is applied locally, which may cause damage to the shaft hole 72a. However, according to the present embodiment, the gear 72 is prevented from being attached in the wrong direction, and the shaft hole 72a can be formed to have a shape that fits with the D-cut shape over the entire axial direction, thereby preventing damage to the shaft hole 72a.

[0094] Furthermore, in this embodiment, the regulating member is E-ring 74, the fitting portion of shaft 73 is groove 73c into which E-ring 74 fits, and protrusion 72s of gear 72 is located at a position corresponding to straight portion 73d when shaft hole 72a is fitted onto shaft 73, and at a position corresponding to the opening of E-ring 74 when E-ring 74 is fitted into groove 73c. This can prevent the protrusion 72s from interfering with the fitting of the E-ring 74 into the groove 73c.

[0095] The restricting member for restricting the movement of the gear 72 toward the free end 73b of the shaft 73 is not limited to the E-ring 74, and may be another member. For example, a hole may be provided in the shaft 73, and a pin-shaped member that fits into the hole may be used as the restricting member.

[0096] Furthermore, gear 72 can move between a position (not shown) where it meshes with gear 71 (see FIG. 12) and a position (see FIG. 12) where it is separated from gear 71, and when gear 72 moves from a position separated from gear 71 to a position where it meshes with gear 72, teeth 72m of gear 72 enter into tooth grooves (not shown) of gear 71 from a corner in the second direction D2, and the corner of gear 72 is formed as chamfered portion 72p. This makes it possible to prevent the corner of teeth 72m of gear 72 from colliding with the teeth of gear 71.

[0097] Next, a modification of the above-mentioned gear 72 will be described. Gear 72A shown in Figures 19 to 21 is a modified example of gear 72 described with reference to Figures 13 to 18. In gear 72A, parts common to gear 72 described above are given the same reference numerals, and duplicated explanations will be omitted. The gear 72A has a protrusion 72s1 in place of the protrusion 72s formed on the gear 72 described above. In this embodiment, the first end 72h is formed by a protruding portion 72s1 that protrudes in the first direction D1. The protruding portion 72s1 is formed so as to protrude in the first direction D1 from the arc portion 72b1 at the opening 72n in the first direction D1. The protruding portion 72s1 is located radially outward of the outer circumferential surface 73g of the shaft 73, which is a cylindrical surface. The opening 72c in the second direction D2 does not have a protruding portion that protrudes in the second direction D2.

[0098] Fig. 20 shows a state in which the gear 72A is fitted onto the shaft 73 in the correct orientation. That is, Fig. 20 shows a state in which the opening 72n of the shaft hole 72a in the first direction D1 contacts the stopper portion 73f. As shown in Fig. 20, when the gear 72A is fitted to the shaft 73 so that the second end 72j is on the free end 73b side of the shaft 73, a groove 73c, which is an example of a fitting portion, is exposed above the opening 72c. This allows an E-ring 74 (see Fig. 15) to fit into the groove 73c.

[0099] 21, when the gear 72A is fitted onto the shaft 73 so that the first end 72h is on the free end 73b side of the shaft 73, the protrusion 72s1 faces the groove 73c. ​​The position where the protrusion 72s1 faces the groove 73c is a position that prevents the E-ring 74 from fitting into the groove 73c. ​​Therefore, in this state, the E-ring 74 cannot be fitted into the groove 73c. In addition, FIG. 21 shows a state in which the second end 72j is in contact with the stopper portion 73f.

[0100] Next, gear 72B shown in Figures 22 to 24 is also a modified example of gear 72 described with reference to Figures 13 to 18. In gear 72B, the same reference numerals are used to designate parts common to gear 72 described above, and duplicated explanations will be omitted. The gear 72B has a protrusion 72s2 in place of the protrusion 72s formed on the gear 72 described above. In this embodiment, the first end 72h is formed by a protruding portion 72s2 that protrudes in the first direction D1. The protruding portion 72s2 is formed to be located radially outward from the straight portion 72b2 of the opening 72n in the first direction D1. As a result, the protruding portion 72s2 is located radially outward from the outer circumferential surface 73g of the shaft 73, which is a cylindrical surface. The opening 72c in the second direction D2 does not have a protruding portion that protrudes in the second direction D2.

[0101] Fig. 23 shows a state in which the gear 72B is fitted to the shaft 73 in the correct orientation. That is, Fig. 23 shows a state in which the opening 72n of the shaft hole 72a in the first direction D1 is in contact with the stopper portion 73f. The protrusion 72s2 is located radially outward of the outer circumferential surface 73g of the shaft 73, and therefore does not engage with the stopper portion 73f. As shown in Fig. 23, when the gear 72B is fitted to the shaft 73 so that the second end 72j is on the free end 73b side of the shaft 73, a groove 73c, which is an example of a fitting portion, is exposed above the opening 72c. This allows an E-ring 74 (see Fig. 15) to fit into the groove 73c.

[0102] Next, when the gear 72B is fitted to the shaft 73 so that the first end 72h is on the free end 73b side of the shaft 73 as shown in Fig. 24, the protrusion 72s2 overlaps with the formation area of ​​the groove 73c in the axial direction. The width W1 (see Fig. 22) of the protrusion 72s2 is set to a width that interferes with the E-ring 74 when the E-ring 74 is fitted into the groove 73c. ​​Therefore, in this state, the E-ring 74 cannot be fitted into the groove 73c. FIG. 24 shows a state in which the second end 72j is in contact with the stopper portion 73f.

[0103] Next, gear 72C shown in Figures 25 to 27 is also a modified example of gear 72 described with reference to Figures 13 to 18. In gear 72C, parts common to gear 72 described above are given the same reference numerals, and duplicated explanations will be omitted. The gear 72C has a protrusion 72s3 in place of the protrusion 72s formed on the gear 72 described above. In this embodiment, the first end 72h is formed by a protruding portion 72s3 that protrudes in the first direction D1. The protruding portion 72s3 is formed so as to protrude in the first direction D1 outside the opening 72n in the first direction D1. The protruding portions 72s3 are formed at predetermined intervals along the circumferential direction outside the opening 72n in the first direction D1. The protruding portions 72s3 are located radially outward of the outer circumferential surface 73g of the shaft 73, which is a cylindrical surface. In this embodiment, the protrusion 72s3 is formed integrally with the rib 72t. The rib 72t is a radially extending rib, and a plurality of ribs 72t are provided at intervals along the circumferential direction. The strength of the gear 72C can be ensured by the rib 72t. Furthermore, by forming the protrusion 72s3 integrally with the rib 72t, the strength of the gear 72C can be ensured while preventing the gear 72C from being attached in an incorrect orientation, as described below. The opening 72c in the second direction D2 does not have a protruding portion that protrudes in the second direction D2.

[0104] Fig. 26 shows a state in which gear 72C is fitted to shaft 73 in the correct orientation. That is, Fig. 26 shows a state in which opening 72n of shaft hole 72a in first direction D1 is in contact with stopper portion 73f. Protrusion 72s3 is located radially outward of outer circumferential surface 73g of shaft 73, which is a cylindrical surface, and therefore does not engage with stopper portion 73f. As shown in Fig. 26, when the gear 72C is fitted to the shaft 73 so that the second end 72j is on the free end 73b side of the shaft 73, a groove 73c, which is an example of a fitting portion, is exposed above the opening 72c. This allows an E-ring 74 (see Fig. 15) to fit into the groove 73c.

[0105] 27, when the gear 72C is fitted onto the shaft 73 so that the first end 72h is on the free end 73b side of the shaft 73, the protrusion 72s3 faces the groove 73c. ​​The protrusion 72s3 prevents the E-ring 74 from fitting into the groove 73c. ​​Therefore, in this state, the E-ring 74 cannot be fitted into the groove 73c. In addition, FIG. 27 shows a state in which the second end 72j is in contact with the stopper portion 73f.

[0106] In this embodiment, the protrusions 72s3 are formed at predetermined intervals along the circumferential direction outside the opening 72n in the first direction D1, but may be provided around the entire circumference without any intervals.

[0107] As described above, when the second end 72j of gear 72A, gear 72B, or gear 72C is brought toward the free end 73b of shaft 73, groove 73c, which is an example of a regulating member, is exposed to an extent that it can be fitted into groove 73c, which is an example of a fitting portion, so that E-ring 74 can be fitted into groove 73c. When the first end 72h of gear 72A, 72B, or 72C is positioned toward the free end 73b of shaft 73, protrusion 72s1, 72s2, or 72s3 is in a position that interferes with the E-ring 74, and therefore protrusion 72s1, 72s2, or 72s3 prevents the E-ring 74 from fitting into groove 73c. Therefore, according to the gear 72A, the gear 72B, or the gear 72C, the same effects as those of the gear 72 described above can be obtained.

[0108] Incidentally, it can be said that the gear 72A, the gear 72B, or the gear 72C has a configuration in which, when the second end 72j is fitted onto the shaft 73 so as to be on the free end 73b side of the shaft 73, the gear 72A, the gear 72B, or the gear 72C does not face the first region in which the groove 73c is formed in the axial direction of the shaft 73, and when the first end 72h is fitted onto the shaft 73 so as to be on the free end 73b side of the shaft 73, the protrusion 72s1, the protrusion 72s2, or the protrusion 72s3 faces the first region. Incidentally, here, the protrusion 72s2 or the protrusion 72s3 faces the first region in such a way as to prevent the E-ring 74 from fitting into the groove 73c.

[0109] Other features of the second cover 52 will be described below. 28 to 30 show a fixing structure 58 that fixes a cover member 57 to the inner plate 54. The second cover 52 includes an inner plate 54 and a cover member 57. Components such as a sensor that detects the medium are provided between the inner plate 54 and the cover member 57, and when replacing these components, it is necessary to remove the cover member 57 from the inner plate 54. Here, since inner plate 54 is made of a metal plate material and cover member 57 is made of a resin material, for example, when cover member 57 is fixed to inner plate 54 by screws, there is a risk that cover member 57 will bend due to the difference in thermal expansion coefficient. Fixing structure 58 solves such a problem.

[0110] Fig. 28 is an enlarged view of region C shown in Fig. 3. Note that a fixing structure 58 is also provided in region D shown in Fig. 3, but since it is the same as the fixing structure 58 provided in region C, a duplicated description will be avoided. The fixing structure 58 includes an E-ring 55 and a screw 56. The E-ring 55 is integrally provided with a protrusion 55a.

[0111] 30, a seat 57a is formed on the cover member 57, and the screw 56 is fixed to the seat 57a. The top of the seat 57a has a stepped structure, and when the screw 56 is fixed to the seat 57a, a gap is formed between the head of the screw 56 and the seat 57a into which the E-ring 55 can fit. As shown in Fig. 29, a hole 54a is formed in the inner plate 54. The inner diameter of the hole 54a is larger than the outer diameter of the head of the screw 56. The inner diameter of the hole 54a is also larger than the outer diameter of the base portion 57a. The head of the screw 56 can protrude outward from the hole 54a as shown in Fig. 29.

[0112] 28 and 30, with the screw head of the screw 56 protruding outward from the hole 54a, the inner plate 54 and the cover member 57 are integrated. From this state, the E-ring 55 can be removed by hooking a finger on the protrusion 55a of the E-ring 55, and by removing the E-ring 55 as shown by the arrow Ej in FIG. 28, the cover member 57 can be easily removed from the inner plate 54.

[0113] Furthermore, when the inner plate 54 and the cover member 57 are integrated as shown in Figure 30, a gap Bs is formed between the hole 54a of the inner plate 54 and the base portion 57a, so that even if a difference in thermal expansion occurs between the inner plate 54 and the cover member 57, this can be absorbed and, in particular, deflection of the cover member 57 can be suppressed.

[0114] Furthermore, the present invention is not limited to the embodiments and modifications described above, but various modifications are possible within the scope of the invention described in the claims, and it goes without saying that these are also included in the scope of the present invention. For example, the first power transmission device 60, the second power transmission device 70, the gear 63, and the gear 72 according to this embodiment may be applied to other parts of the printer 1, and may also be applied to an image reading device that reads document images or other devices, not limited to the printer 1. [Explanation of symbols]

[0115] 1...inkjet printer, 2...casing, 3...first media cassette, 7...internal discharge section, 8...tilt panel, 10A, 10B, 10C, 10D...ink storage section, 11A, 11B, 11C, 11D...mounting section, 12...waste liquid storage section, 13...conveyor belt, 14, 15...pulley, 19...supply roller, 20...separation roller, 21...pick roller, 25...feed roller pair, 28, 31, 32, 33, 34, 35A, 35B, 36, 37, 38...conveyor roller pair, 41...flap , 43...head unit, 44...line head, 51...first cover, 51a...rotating shaft, 51c...grip, 52...second cover, 52a...hinge, 52c...grip, 53...middle door, 53a...rotating shaft, 54...inner plate, 54a...hole, 55...E-ring, 55a...projection, 56...screw, 57...cover member, 57a...base, 58...fixing structure, 59...gear, 60...first power transmission device, 61...gear, 62...gear, 63...gear, 63a...shaft hole, 63b...inner surface, 63c...opening, 6 3d...recess, 63e...rib, 63f...inclined surface, 63g...chamfered portion, 63h...first end, 63j...second end, 63k...cylindrical portion, 63m...tooth, 63n...opening, 64...gear, 65...shaft, 65a...base end, 65b...free end, 65c...groove, 66...shaft, 67...E-ring, 68...frame, 70...second power transmission device, 71...gear, 72, 72A, 72B, 72C...gear, 72a...shaft hole, 72b1...circular arc portion, 72b2...straight portion, 72c...opening, 72h...first end, 72j...second end, 72m...tooth, 72n...opening, 72p...chamfered portion, 72s, 72s1, 72s2, 72s3...protruding portion, 72t...rib, 73...shaft, 73b...free end, 73c...groove, 73d...straight portion, 73e...arc portion, 73f...stopper portion, 73g...outer periphery, 74...E-ring, 90...post-processing unit, 91...processing tray, 92...post-processing portion, 93...loading tray, 100...medium transport device, T1...transport path during recording, T2...switchback path, T3...connection path, T4...reversal path, T5...ejection path

Claims

1. Axle and a gear having a shaft hole that fits onto the shaft; a restricting member that is fitted into a fitting portion formed on the shaft and restricts movement of the gear toward a free end side of the shaft; A power transmission device having The gear has one axial direction of the shaft hole defined as a first direction and the other axial direction defined as a second direction, a first end portion that is an outermost end portion in the first direction; a second end portion that is the outermost end portion in the second direction; having When the second end of the gear is located on a free end side of the shaft, the restricting member can be fitted into the fitting portion, When the first end of the gear is located on the free end side of the shaft, a part of the gear prevents the regulating member from fitting into the fitting portion. A power transmission device characterized by:

2. 2. The power transmission device according to claim 1, the first end of the gear is formed by a cylindrical portion having the shaft hole therein and having an outer diameter smaller than an outer diameter of the gear, an opening of the shaft hole on the second end side is formed at a bottom of a recess that is recessed in the first direction more than an outer periphery, When the second end of the gear is disposed on a free end side of the shaft, the fitting portion is exposed by the recess, so that the regulating member can be fitted into the fitting portion, When the first end of the gear is disposed on the free end side of the shaft, the cylindrical portion covers at least a portion of the fitting portion, thereby preventing the regulating member from fitting into the fitting portion. A power transmission device characterized by:

3. 3. The power transmission device according to claim 2, The gear has an inclined surface that is inclined from a center in a radial direction toward an outer side in the second direction on an inner side of the recess. A power transmission device characterized by:

4. 4. The power transmission device according to claim 3, The restricting member is an E-ring, the fitting portion is a groove into which the E-ring fits, When the E-ring is removed from the fitting portion, a part of the E-ring is hooked on the groove with the outer periphery of the E-ring resting on the inclined surface. A power transmission device characterized by:

5. 2. The power transmission device according to claim 1, The gear is a first distance is a distance along the axial direction from the first end to an opening of the shaft hole in the second direction, and a second distance is a distance along the axial direction from the second end to the opening of the shaft hole in the first direction, the second distance being longer than the first distance; When the second end of the gear is disposed on the free end side of the shaft, the fitting portion is exposed, so that the regulating member can be fitted into the fitting portion, When the first end of the gear is disposed on the free end side of the shaft, an inner circumferential surface of the shaft hole covers at least a part of the fitting portion, thereby preventing the regulating member from fitting into the fitting portion. A power transmission device characterized by:

6. 2. The power transmission device according to claim 1, the second end of the gear is formed by a protruding portion protruding in the second direction from an opening of the shaft hole in the second direction, When the second end of the gear is disposed on a free end side of the shaft, the restricting member can be fitted to a portion of the fitting portion except for a portion covered by the protruding portion, When the first end of the gear is disposed on the free end side of the shaft, an inner circumferential surface of the shaft hole covers the fitting portion, thereby preventing the regulating member from fitting into the fitting portion. A power transmission device characterized by:

7. 7. The power transmission device according to claim 6, The portion of the shaft into which the shaft hole is fitted is formed in a D-cut shape having an arc portion and a straight portion along the outer periphery, The shaft hole has a shape that fits with the D-cut shape over the entire area in the axial direction. A power transmission device characterized by:

8. 8. The power transmission device according to claim 7, The restricting member is an E-ring, the fitting portion is a groove into which the E-ring fits, The protrusion is provided at a position corresponding to the straight portion when the shaft hole is fitted onto the shaft, and at a position corresponding to an opening of the E-ring when the E-ring is fitted into the groove. A power transmission device characterized by:

9. 9. The power transmission device according to claim 8, The gear is a first gear, and a second gear is meshed with the first gear, the first gear is movable between a position where it meshes with the second gear and a position where it is spaced apart from the second gear, When the first gear moves from a position away from the second gear to a position meshing with the second gear, the teeth of the first gear enter the tooth grooves of the second gear from a corner portion, The corners are chamfered or rounded. A power transmission device characterized by:

10. 2. The power transmission device according to claim 1, the first end of the gear is formed by a protruding portion that protrudes in the first direction from an opening of the shaft hole in the first direction, the protruding portion is located radially outward of an outer circumferential surface of the shaft, the outer circumferential surface being a cylindrical surface, when the second end of the gear is disposed on the free end side of the shaft, the fitting portion is exposed to an extent that the regulating member can be fitted into the fitting portion, so that the regulating member can be fitted into the fitting portion, When the first end of the gear is disposed on the free end side of the shaft, the protruding portion is located at a position where it interferes with the regulating member, and therefore the protruding portion prevents the regulating member from fitting into the fitting portion. A power transmission device characterized by:

11. a recording unit for recording on a medium; A pair of transport rollers for transporting the medium; A drive source for the pair of conveying rollers; The power transmission device according to claim 1 , which transmits power of the drive source to the pair of transport rollers; A recording device comprising:

12. A gear having a shaft hole that fits onto a shaft, One of the axial directions of the shaft hole is defined as a first direction and the other is defined as a second direction, a first end portion that is an outermost end portion in the first direction; a second end portion that is the outermost end portion in the second direction; having a first distance is a distance along the axial direction from the first end to an opening of the shaft hole in the second direction, and a second distance is a distance along the axial direction from the second end to the opening of the shaft hole in the first direction, the first distance being shorter than the second distance; When the second end is located on the free end side of the shaft, an inner circumferential surface of the shaft hole does not cover an outer circumferential surface of the shaft in a first region in the axial direction of the shaft, When the first end is located on the free end side of the shaft, an inner circumferential surface of the shaft hole covers an outer circumferential surface of the shaft in the first region in the axial direction of the shaft. A gear characterized by:

13. A gear having a shaft hole that fits onto a shaft, One of the axial directions of the shaft hole is defined as a first direction and the other is defined as a second direction, a first end portion that is an outermost end portion in the first direction; a second end portion that is the outermost end portion in the second direction; having the second end is formed by a protruding portion protruding in the second direction from an opening of the shaft hole in the second direction, When the second end is located on the free end side of the shaft, the protrusion covers only a part of a first region in the axial direction of the shaft, When the first end is located on the free end side of the shaft, an inner circumferential surface of the shaft hole covers the first region. A gear characterized by:

14. A gear having a shaft hole that fits onto a shaft, One of the axial directions of the shaft hole is defined as a first direction and the other is defined as a second direction, a first end portion that is an outermost end portion in the first direction; a second end portion that is the outermost end portion in the second direction; having the first end is formed by a protruding portion that protrudes in the first direction from an opening of the shaft hole in the first direction, the protruding portion is located radially outward of an outer circumferential surface of the shaft, the outer circumferential surface being a cylindrical surface, When the second end of the gear is disposed on the free end side of the shaft, a part of the gear does not face the first region in the axial direction of the shaft, When the first end of the gear is disposed on a free end side of the shaft, the protruding portion faces the first region in the axial direction of the shaft. A gear characterized by:

Images