Scissors gear, actuator, and reaction force imparting device

Abstract

An output transmission gear (48, 38) meshes with a mating gear and is rotatable about an axis. An urging gear (46, 36) engages with the mating gear together with the output transmission gear, and rotates together with the output transmission gear. Urging members (81‒89) are provided between the output transmission gear and the urging gear, and urge the output transmission gear so as to rotate relative to the urging gear in one direction, thereby eliminating backlash of the output transmission gear. The output transmission gear and the urging gear have load-receiving parts (487, 488, 465, 466, 387, 388, 365, 366) for respectively receiving the loads of the urging members. At least one of the output transmission gear and the urging gear has a plurality of load-receiving parts for receiving the loads of the urging members for urging the output transmission gear so as to relatively rotate in a first direction with respect to the urging gear and in a second direction opposite to the first direction.

Description

Scissors gear, actuator and reaction force applying device CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Japanese Application No. 2024-061574, filed on April 5, 2024, the contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a scissors gear, an actuator, and a reaction force applying device.

[0003] Conventionally, scissors gears have been known as gears that generally eliminate backlash. For example, the scissors gear disclosed in Patent Document 1 has a spring built in between two coaxially arranged gears.

[0004] Furthermore, conventionally, there are known reaction force applying devices that can apply a reaction force to an accelerator pedal that is depressed by a driver in response to the pedal depression force of the driver. For example, the reaction force applying device disclosed in Patent Document 2 includes an actuator that generates a reaction force against the pedal.

[0005] Japanese Utility Model Application Publication No. 55-158349 European Patent Application Publication No. 2607139

[0006] In the actuator of Patent Document 2, a torsion spring biases a lever connected to a reducer so that it always abuts against the accelerator pedal lever. Therefore, when the accelerator is operated, the internal gear is also driven in accordance with the pedal operation. With this configuration, backlash in the gears can cause play during operation, which can result in abnormal noise and delays in load transmission.

[0007] The general scissors gear disclosed in Patent Document 1 and the like has a structure in which a "biased gear" on the biasing side abuts against a load-receiving surface of a "biasing gear" on the biasing side. When applied to the actuator of Patent Document 2, the biasing direction of the scissors gear is determined to be one direction relative to the output direction of the actuator. If the output direction of the actuator is reversed, the biasing direction of the scissors gear must be reversed, which increases the number of gear types and management man-hours.

[0008] Patent Document 1 describes that assembly is made easier by providing a C-shaped spring in the space provided where the two gears meet, with both ends of the spring engaging with small holes in each gear.However, Patent Document 1 does not describe anything about facilitating the assembly of scissors gears that have a structure in which a coil spring is compressed in the circumferential direction of the gears.

[0009] An object of the present disclosure [Group A] is to provide a scissors gear that can reverse the biasing direction using a common gear, an actuator to which the scissors gear is applied, and a reaction force applying device that uses the actuator.

[0010] The object of the present disclosure [Group B] is to provide a scissors gear that is easy to assemble and has a structure in which a coil spring is compressed in the circumferential direction of the gear. The object of the present disclosure [Group B] is also to provide an actuator to which the scissors gear is applied, and a reaction force applying device using the actuator.

[0011] A first aspect of the present disclosure [Group A] is a scissors gear including an output transmission gear, a biasing gear, and one or more biasing members. The output transmission gear meshes with a mating gear and is rotatable about an axis. The biasing gear meshes with the mating gear together with the output transmission gear and rotates in conjunction with the output transmission gear.

[0012] The biasing member is provided between the output transmission gear and the biasing gear, and biases the output transmission gear so as to rotate relative to the biasing gear in one direction, thereby removing backlash in the output transmission gear.

[0013] The output transmission gear and the biasing gear each have a load receiving portion that receives a load from the biasing member. At least one of the output transmission gear and the biasing gear has a plurality of load receiving portions that receive a load from the biasing member that biases the output transmission gear to rotate relatively to the biasing gear in a first direction and a second direction opposite to the first direction.

[0014] In the first aspect of the present disclosure [Group A], by changing the assembly position of the biasing member in a gear having multiple load receiving portions, it is possible to reverse the biasing direction using a common gear, thereby avoiding an increase in the number of management steps.

[0015] A first aspect of the present disclosure [Group B] is a scissors gear assembled with an output transmission gear, a biasing gear, and one or more coil springs. The output transmission gear meshes with a mating gear and is rotatable about an axis. The biasing gear meshes with the mating gear together with the output transmission gear and rotates in conjunction with the output transmission gear.

[0016] The spring is housed in at least one of spring grooves recessed in the opposing surfaces of the output transmission gear and the biasing gear, and is compressed in the circumferential direction of the gears to bias the output transmission gear to rotate in one direction relative to the biasing gear, thereby eliminating backlash in the output transmission gear.

[0017] The length of the spring groove in the gear circumferential direction is greater than the free length of the spring, and the width of the spring groove in the gear radial direction is greater than the outer diameter of the spring.

[0018] In the first aspect of the present disclosure [Group B], the spring can be inserted into the spring groove without being compressed during assembly, making assembly easy.

[0019] A second aspect of the present disclosure is an actuator capable of unidirectionally outputting a reaction force against an external force, the actuator comprising: a housing; a drive source; and a reducer. The drive source has a drive gear that outputs a drive force. The reducer reduces the speed of the drive force from the drive source.

[0020] The reducer has an output gear and an intermediate gear. The output gear is rotatable around an output shaft supported by the housing. The intermediate gear meshes with the drive gear and the output gear and is rotatable around an intermediate shaft supported by the housing. At least one of the output gear and the intermediate gear is configured as a scissors gear of the first aspect. This eliminates backlash in the gear configured as a scissors gear.

[0021] A third aspect of the present disclosure is a reaction force applying device that can apply a reaction force corresponding to the pedal depression force to a pedal operated by a driver in an accelerator device, and includes the actuator of the second aspect and a load transmission member. The load transmission member rotates integrally with the output shaft and applies a reaction force in the pedal return direction. This can minimize abnormal noise and discomfort caused by backlash when the driver operates the pedal.

[0022] The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which Fig. 1A is a plan view of a biasing gear constituting a scissors gear (full circumference gear) of a first embodiment, Fig. 1B is a cross-sectional view of the biasing gear constituting the scissors gear (full circumference gear) of the first embodiment taken along line Ib-Ib, Fig. 2A is a plan view of an output transmission gear constituting the scissors gear of the first embodiment, Fig. 2B is a cross-sectional view of the output transmission gear constituting the scissors gear of the first embodiment taken along line IIb-IIb, Fig. 3 is a side view of the scissors gear of the first embodiment in an assembled state, and Fig. 4 is an axial view of the scissors gear of the first embodiment in an assembled state. 5 is a cross-sectional view of the opposing surface (VV line in FIG. 3) of the scissors gear (first / second direction biasing specification) of the first embodiment, FIG. 6 is a plan view of the scissors gear (first / second direction biasing specification) of the first embodiment in an assembled state, FIG. 7A is a plan view of the biasing gear constituting the scissors gear (sector gear) of the second embodiment, FIG. 7B is a cross-sectional view of the biasing gear constituting the scissors gear (sector gear) of the second embodiment taken along line VIIb-VIIb, FIG. 8A is a plan view of the output transmission gear constituting the scissors gear of the second embodiment, and FIG. 8B is a FIG. 9 is a cross-sectional view of the scissors gear according to the second embodiment taken along line VIIIb-VIIIb of an output transmission gear constituting the scissors gear of the second embodiment; FIG. 10 is a cross-sectional view of the opposing surface (line X-X in FIG. 9) of the scissors gear (first / second direction biasing specification) of the second embodiment; FIG. 11 is a plan view of the biasing gear and output transmission gear of the scissors gear (full circumference gear) of the third embodiment; FIG. 12 is a plan view of the biasing gear and output transmission gear of the scissors gear (sector gear) of the fourth embodiment; and FIG. 13 is a cross-sectional view of the scissors gear (full circumference gear) of the fifth embodiment. FIG. 14 is a cross-sectional view of an opposing surface of a scissors gear (sector gear) of a sixth embodiment, FIG. 15 is a cross-sectional view of an opposing surface of a scissors gear (full circumference gear) of a seventh embodiment, FIG. 16 is a cross-sectional view of an opposing surface of a scissors gear (full circumference gear) of an eighth embodiment, FIG. 17 is a cross-sectional view of an opposing surface of a scissors gear (full circumference gear) of a ninth embodiment, FIG. 18 is a cross-sectional view of an opposing surface of a scissors gear (full circumference gear) of a tenth embodiment, FIG. 19 is a diagram of a first configuration example of an accelerator device, and FIG. 20 is a diagram of a second configuration example of an accelerator device.21 is a plan view of an actuator of a reaction force application device, FIG. 22 is a schematic cross-sectional view of an actuator in which scissors gears are applied to an intermediate gear and an output gear, FIG. 23 is a diagram explaining elimination of backlash of the intermediate gear by scissors gears, FIG. 24 is a schematic cross-sectional view of an actuator in which scissors gears are applied to an intermediate gear and backlash of the output gear is eliminated by a return spring, FIG. 25 is a perspective view of the output gear and return spring, FIG. 26 is a diagram explaining elimination of backlash of the output gear by a return spring, and FIG. 27 is a flowchart of assembling scissors gears. 28 is a diagram showing the first step, FIG. 29 is a cross-sectional view of an opposing surface showing step 2-1 of the second step, FIG. 30 is a cross-sectional view of an opposing surface showing steps 2-2 and 2-3 of the second step, FIG. 31 is a schematic partial cross-sectional view showing steps 2-1 to 2-3 of the second step, FIG. 32 is a cross-sectional view of an opposing surface explaining the restriction of the spring deflection amount, FIG. 33 is a cross-sectional view showing the relationship between the shaft fitting length and the protrusion amount of the protrusion in the second step, FIG. 34 is a diagram corresponding to FIG. 33 for a scissors gear of a modified example, FIG. 35 is a diagram showing the assembly of the retaining member in the third step, and FIG. 36 is a diagram showing gear tooth phase alignment in the fourth step.

[0023] Several embodiments of the scissors gear according to the present disclosure, as well as embodiments of an actuator to which the scissors gear is applied and a reaction force applying device using the actuator, will be described with reference to the drawings. Substantially identical components in the several embodiments are designated by the same reference numerals, and description thereof will be omitted. As embodiments of the scissors gear that eliminates backlash with a mating gear, the following embodiments are broadly divided into [Group A] and [Group B]. The scissors gears of [Group A] are capable of reversing the biasing direction using a common gear. The scissors gears of [Group B] are structured so that a coil spring is compressed in the circumferential direction of the gear, and are easy to assemble.

[0024] Both the scissors gears of [Group A] and [Group B] are applied to actuators of reaction force applying devices that can apply a reaction force to the pedal operated by the driver in an accelerator device according to the force applied by the driver. The actuator outputs the rotational force of the motor, which is the drive source, via a drive gear, an intermediate gear, and an output gear, thereby rotating a load transmission member. The intermediate gear or output gear of this actuator is composed of a scissors gear. The configuration of the actuator and the reaction force applying device will be described in the explanation of the scissors gears of [Group A].

[0025] [Group A: Scissors gears capable of reversing the biasing direction using a common gear] (First embodiment) A scissors gear according to a first embodiment applied to a full-circumference gear will be described with reference to FIGS. 1A to 6. The scissors gear according to the first embodiment includes an output transmission gear 48, a biasing gear 46, and a spring 81 as "one or more biasing members," and removes backlash in the output transmission gear 48. The output transmission gear 48 and the biasing gear 46 have gear teeth formed on their entire circumferences that are identical in basic specifications other than thickness, such as the number of teeth and pitch circle diameter. The spring 81 is a coil spring that is used in a compressed state.

[0026] The output transmission gear 48 meshes with the mating gear and is rotatable about axis O. The biasing gear 46 meshes with the mating gear together with the output transmission gear 48 and rotates along with the output transmission gear 48. A spring 81 is provided between the output transmission gear 48 and the biasing gear 46 and biases the output transmission gear 48 to rotate relative to the biasing gear 46 in one direction. In a typical scissors gear, the "mating gear" with which the output transmission gear 48 and the biasing gear 46 mesh may be any. As will be described later, when a scissors gear is used as an intermediate gear in the actuator of the reaction force applying device, the "mating gear" with which the output transmission gear 48 and the biasing gear 46 mesh is the drive gear 22.

[0027] 1A and 1B show a plan view and an axial cross-sectional view of the biasing gear 46. FIGS. 2A and 2B show a plan view and an axial cross-sectional view of the output transmission gear 48. The circumferential direction of the gears 46 and 48 in the plan view is referred to as the "gear circumferential direction" where appropriate, and the radial direction of the gears 46 and 48 is referred to as the "gear radial direction" where appropriate. FIGS. 3 and 4 show a side view and an axial cross-sectional view in an assembled state. Based on the up-down direction in FIGS. 3 and 4 , the surface of the biasing gear 46 facing the output transmission gear 48 is referred to as the lower surface 462, and the surface opposite the lower surface 462 is referred to as the upper surface 461. The surface of the output transmission gear 48 facing the biasing gear 46 is referred to as the upper surface 481, and the surface opposite the upper surface 481 is referred to as the lower surface 482. The lower surface 462 of the biasing gear 46 and the upper surface 481 of the output transmission gear 48, which face each other, are referred to as "opposing surfaces."

[0028] The opposite rotation directions of the output transmission gear 48 relative to the biasing gear 46 due to the load of the spring 81 are referred to as a "first direction" and a "second direction." In the following embodiments, when viewed from the perspectives of FIGS. 1A and 2A , the direction in which the output transmission gear 48 rotates clockwise relative to the biasing gear 46 is referred to as the "first direction," and the direction in which the output transmission gear 48 rotates counterclockwise relative to the biasing gear 46 is referred to as the "second direction." When the output transmission gear 48 is used as a reference, the biasing gear 46 that receives a load in the first direction rotates counterclockwise relative to the biasing gear 46, and the biasing gear 46 that receives a load in the second direction rotates clockwise relative to the biasing gear 46.

[0029] 1A and 1B, the biasing gear 46 has a shaft hole 460 penetrating along the axis O, and gear teeth are formed around the entire circumference. Two arc-shaped spring grooves 463 are recessed in the opposing surface 462, symmetrically about the axis O, over a section of nearly 180° in the gear circumferential direction. Load receiving portions 465, 466 that receive the load of the spring 81 are provided at both ends of the circumferential direction of each spring groove 463. The load receiving portion 465 receives a load in a first direction. The load receiving portion 466 receives a load in a second direction. The walls that constitute each load receiving portion 465, 466 protrude from the opposing surface 462 and form protrusions 467. The viewing hole 464 will be described later with reference to FIG. 6.

[0030] Each of the load receiving portions 465, 466 has a load receiving surface Sa1, Sa2 formed along a plane passing through the rotation center O of the gear, which receives the load of the spring 81. This allows the reaction force of the spring 81 to be applied in the gear rotation direction, preventing the generation of unnecessary bearing load.

[0031] As shown in Figures 2A and 2B, the output transmission gear 48 has a shaft hole 480 that penetrates along the axis O, and gear teeth are formed on the entire circumference. Four arc-shaped spring grooves 483 are recessed in the opposing surface 481, symmetrically arranged with respect to the axis O. Load receiving portions 487, 488 that receive the load of the spring 81 are provided back-to-back at the boundaries between adjacent spring grooves 483. The load receiving portion 487 receives a load in a first direction. The load receiving portion 488 receives a load in the direction shown in Figure 2. The walls that constitute each of the load receiving portions 487, 488 protrude from the opposing surface 481, forming protrusions 489.

[0032] Each of the load receiving portions 487, 488 has a load receiving surface Sb1, Sb2 formed along a plane passing through the rotation center O of the gear, which receives the load of the spring 81. This allows the reaction force of the spring 81 to be applied in the gear rotation direction, preventing the generation of unnecessary bearing load.

[0033] The wall of spring groove 483 opposite load receiving portion 487 forms rear wall 485, and the wall opposite load receiving portion 488 forms rear wall 486. Also, there are formed stepped walls 495 where the groove width of spring groove 483 in the gear radial direction decreases from the rear wall 485 side to the load receiving portion 487 side, and stepped walls 496 where the groove width of spring groove 483 in the gear radial direction decreases from the rear wall 486 side to the load receiving portion 488 side. The significance of this will be explained in [Group B].

[0034] A small diameter gear portion 47 having gear teeth with a smaller diameter than the output transmission gear 48 is provided on the lower surface 482 side of the output transmission gear 48. The small diameter gear portion 47 is provided depending on the configuration of the applied actuator, etc., and is not essential for the configuration of a general scissors gear.

[0035] 3 and 4, the biasing gear 46 and the output transmission gear 48 are assembled coaxially with a spring 81 sandwiched therebetween. Here, the plate thickness Tb of the output transmission gear 48 is set to be larger than the plate thickness Ta of the biasing gear 46. This allows the plate thickness of each gear 46, 48 to be set appropriately, and the plate thickness of the entire scissors gear can be reduced.

[0036] Furthermore, the biasing gear 46 and the output transmission gear 48 rotate around the common shaft 40. This minimizes misalignment of the rotation axes compared to a configuration in which the biasing gear 46 and the output transmission gear 48 rotate individually around separate shaft members.

[0037] Figure 5 shows an "opposing surface cross-sectional view" corresponding to the cross-section taken along line VV in Figure 3. The "opposing surface cross-sectional view" in the following embodiments of the full circumference gear is equivalent to the cross-section taken along line VV in Figure 3. In the opposing surface cross-sectional view, the cross-section of the protrusion 467 of the biasing gear 46 is illustrated by hatching.

[0038] Hereinafter, the specification for biasing the output transmission gear 48 in the first direction relative to the biasing gear 46 will be referred to as the "first direction biasing specification," and the specification for biasing the output transmission gear 48 in the second direction relative to the biasing gear 46 will be referred to as the "second direction biasing specification." In the first direction biasing specification, the spring 81 is set between the load receiving portion 465 of the biasing gear 46 and the load receiving portion 487 of the output transmission gear 48. In the second direction biasing specification, the spring 81 is set between the load receiving portion 466 of the biasing gear 46 and the load receiving portion 488 of the output transmission gear 48.

[0039] In this way, both the biasing gear 46 and the output transmission gear 48 have a plurality of load receiving portions 487, 488, 465, 466 that receive the load of the spring 81 that biases the output transmission gear 48 to rotate in the first direction and the second direction relative to the biasing gear 46. In the first embodiment, by changing the assembly position of the spring 81 in a gear having a plurality of load receiving portions, it is possible to reverse the biasing direction using a common gear. Therefore, an increase in management man-hours is avoided.

[0040] Figure 6 shows a plan view of the assembled state corresponding to Figure 5. The rotation arrow in Figure 6 indicates the direction in which the biasing gear 46, which receives a load, rotates relative to the output transmission gear 48. The biasing gear 46 is formed with viewing holes 464 that allow the presence or absence of the spring 81 in the assembled position to be visually confirmed from the outside on the top surface 461 side. In this example, four viewing holes 464 are formed. By allowing an operator to visually confirm that the spring 81 is correctly set in the correct assembly position and that the spring 81 is not set in an unused position, incorrect assembly of the spring 81 is prevented.

[0041] Second Embodiment A scissors gear according to a second embodiment applied to a sector gear will be described with reference to FIGS. 7A to 10. While the first embodiment uses reference numerals beginning with "4," the second embodiment uses reference numerals beginning with "3." Essentially similar to the first embodiment, the scissors gear according to the second embodiment includes an output transmission gear 38, a biasing gear 36, and a spring 81 as "one or more biasing members," and eliminates backlash in the output transmission gear 38. The output transmission gear 38 and the biasing gear 36 have gear teeth formed on a portion of their circumferences, with the same basic specifications except for thickness. The scissors gear according to the second embodiment rotates within the angular range within which the gear teeth are formed.

[0042] 9 , the lower surface 362 of the urging gear 36 and the upper surface 381 of the output transmission gear 38, which face each other, are referred to as "opposing surfaces." The surface of the urging gear 36 opposite the opposing surface 362 is referred to as the upper surface 361. The surface of the output transmission gear 38 opposite the opposing surface 381 is referred to as the lower surface 382.

[0043] 7A and 7B, the biasing gear 36 has a cylindrical portion fitting hole 360 ​​that penetrates along the axis O. Two arc-shaped spring grooves 363 are recessed in the opposing surface 362 of the biasing gear 36, symmetrically with respect to the reference plane Ss. At the boundary between adjacent spring grooves 363, load receiving portions 365 and 366 that receive the load of the spring 81 are provided back-to-back. The load receiving portion 365 receives a load in a first direction. The load receiving portion 366 receives a load in a second direction. Each load receiving portion 365 and 366 has a load receiving surface Sa1 and Sa2 that receive the load of the spring 81, formed along a plane that passes through the rotation center O of the gear.

[0044] The walls constituting the load receiving portions 365, 366 of the biasing gear 36 protrude from the opposing surface 362 to form protrusions 367. Also, a viewing hole 364 is formed in the biasing gear 36.

[0045] As shown in FIGS. 8A and 8B , the output transmission gear 38 has a cylindrical portion 389 that protrudes from the opposing surface 381 around the axis O and is fitted into the cylindrical portion fitting hole 360 ​​of the biasing gear 36 so as to be rotatable relative to the axis O. A shaft hole 380 with a rotation prevention shape is formed inside the cylindrical portion 389 and along the axis O. An arc-shaped spring groove 383 is recessed symmetrically with respect to the reference plane Ss in the opposing surface 381 of the output transmission gear 38. Load receiving portions 387 and 388 that receive the load of the spring 81 are provided at both circumferential ends of the spring groove 383. The load receiving portion 387 receives a load in a first direction. The load receiving portion 388 receives a load in a second direction. Each load receiving portion 387 and 388 has load receiving surfaces Sb1 and Sb2 that receive the load of the spring 81 along a plane passing through the rotation center O of the gear.

[0046] As shown in Figure 9, the biasing gear 36 and the output transmission gear 38 are assembled with a spring 81 sandwiched therebetween. The plate thickness Tb of the output transmission gear 38 is set to be larger than the plate thickness Ta of the biasing gear 36. The biasing gear 36 and the output transmission gear 38 rotate about a common shaft 30. Figure 10 shows a "cross-sectional view of the opposing surfaces" corresponding to the cross section taken along line X-X in Figure 9. In the second embodiment, too, by changing the assembly position of the spring 81 in a gear having multiple load receiving portions, the biasing direction can be reversed using a common gear.

[0047] Third and Fourth Embodiments Scissor gears according to third and fourth embodiments will be described with reference to Figures 11 and 12. In the third and fourth embodiments, only one of the output transmission gear and the biasing gear has a plurality of load receiving portions so that the biasing direction can be reversed.

[0048] 11, the third embodiment of the full-circumference gear is the same as the first embodiment in that it shares the biasing gear 46. The output transmission gear 48 has a spring groove 483 formed only on the side having the load receiving portion 487 with the first-direction biasing specification. When manufacturing a scissors gear with the second-direction biasing specification, the biasing gear 46 is shared, and a separate part is used for the output transmission gear.

[0049] In the fourth embodiment of the sector gear shown in Fig. 12, the output transmission gear 38 is the same as in the second embodiment. The biasing gear 36 has a spring groove 363 formed only on the side having the load receiving portion 365 with the first-direction biasing specification. When manufacturing a scissors gear with the second-direction biasing specification, the output transmission gear 38 is shared, and a separate biasing gear is used.

[0050] In the third and fourth embodiments, the gears whose biasing direction is reversible can share parts as in the first and second embodiments. Also, by not sharing parts for the gears whose biasing direction is not reversible, incorrect assembly is prevented. In this way, in the embodiments of group A, at least one of the output transmission gear and the biasing gear only needs to have a plurality of load receiving portions so that the biasing direction is reversible.

[0051] The fifth to tenth embodiments are variations of the scissors gear that include a biasing member other than the spring (coil compression spring) 81. In any of the variations, the biasing direction can be reversed using the common biasing gears 46, 36 and output transmission gears 48, 38, thereby avoiding an increase in the number of management steps.

[0052] 13 and 14 show cross-sectional views of opposing surfaces of a scissors gear equipped with a torsion spring 82 as a biasing member. The torsion spring 82 generates a torsional load on the coil portion by compressing both ends of a wire wound in a coil shape in the circumferential direction.

[0053] 13 , a torsion spring 82 is disposed so as to surround the shaft 40 of the full circumference gear. In the first-direction biasing specification, the load receiving portion 465 of the biasing gear 46 and the load receiving portion 487 of the output transmission gear 48 receive the torsional load at both ends of the torsion spring 82. In the second-direction biasing specification, the load receiving portion 466 of the biasing gear 46 and the load receiving portion 488 of the output transmission gear 48 receive the torsional load at both ends of the torsion spring 82.

[0054] 14 , a torsion spring 82 is disposed so as to surround the sector gear shaft 30. In the first-direction biasing specification, the load receiving portion 365 of the biasing gear 36 and the load receiving portion 387 of the output transmission gear 38 receive the torsional load at both ends of the torsion spring 82. In the second-direction biasing specification, the load receiving portion 366 of the biasing gear 36 and the load receiving portion 388 of the output transmission gear 38 receive the torsional load at both ends of the torsion spring 82.

[0055] (Seventh to Tenth Embodiments) Figures 15 to 18 show cross-sectional views of opposing surfaces of scissors gears equipped with other biasing members 83, 84, 85, and 86, using a full circumference gear as an example. The same can be applied to sector gears. In the seventh embodiment shown in Figure 15, a spiral spring 83 is used. Load receiving portions 465 and 466 of the biasing gear 46 are arranged on the radially outer side, and load receiving portions 487 and 488 of the output transmission gear 48 are arranged on the radially inner side. The output transmission gear 48 is biased by the load of the wound spiral trying to return to its original shape.

[0056] 16 uses a C-shaped snap ring 84. The C-shaped snap ring 84 is disposed so as to surround the shaft 40 in the same manner as the torsion spring 82, and the output transmission gear 48 is biased by the load that tends to open the ends in the circumferential direction.

[0057] 17 uses a U-shaped leaf spring 85. The output transmission gear 48 is biased by the load that tends to open the U-shaped leaf spring 85 in the circumferential direction. The number of U-shaped leaf springs 85 is not limited to one, and multiple U-shaped leaf springs 85 may be used.

[0058] 18 uses a tension spring 86. Load receiving portions 465, 466 of the biasing gear 46 and load receiving portions 487, 488 of the output transmission gear 48 are formed, for example, in a cylindrical shape in accordance with the hook shape of the tension spring 86. The output transmission gear 48 is biased by the load of the tension spring 86 trying to return when it is pulled. The number of tension springs 86 is not limited to one, and multiple springs 86 may be used.

[0059] [Configuration of the Actuator of the Reaction Force Applicator] Next, the configuration of the actuator of the reaction force applicator to which the scissors gear of each embodiment of Group A is applied will be described with reference to Figures 19 to 26. Figures 19 and 20 show two configuration examples of an accelerator device attached to the floor panel 2 of a vehicle. The reaction force applicator 3 is capable of applying a reaction force Fr corresponding to the driver's depression force Ft to a pedal 72 of the accelerator devices 701, 702 that is depressed by the driver.

[0060] As shown in FIGS. 19 to 21, the reaction force application device 3 includes an actuator 10 capable of outputting a reaction force in one direction against an external force, and a load transmission member 60 that transmits the load output by the actuator 10.

[0061] The actuator 10 includes a housing 11, a motor 20 serving as a drive source, and a reducer 4 that reduces the speed of the drive force from the motor 20. The motor 20 has a drive gear 22 fixed to a motor shaft 21 (see FIG. 22 ). When the motor 20 is energized, the drive gear 22 outputs a drive force (torque). The reducer 4 has an intermediate gear 44 and an output gear 33. The intermediate gear 44 meshes with the drive gear 22 and the output gear 33, and is rotatable about an intermediate shaft 40 supported by the housing 11. The output gear 33 meshes with the intermediate gear 44, and is rotatable about an output shaft 30 supported by the housing 11.

[0062] The load transmission member 60 is formed into a rod shape from metal or the like, and one end is connected to the output shaft 30. The load transmission member 60 rotates integrally with the output shaft 30 of the actuator 10, and applies a reaction force Fr in the return direction of the pedal 72.

[0063] FIG. 19 shows a floor-mounted accelerator device 701 as a first configuration example. A pedal 72 is provided directly above a pedal housing 71 attached to a floor panel 2. The driver applies a depression force Ft to a pad 73 to depress the pedal 72. In the actuator 10 of the reaction force applying device 3, the drive gear 22 rotates clockwise, the intermediate gear 44 rotates counterclockwise, and the output gear 33 rotates clockwise, as viewed in the figure. As a result, the load transmission member 60 applies a reaction force Fr to the pedal 72 in the direction opposite to the depression force Ft.

[0064] FIG. 20 shows a suspended accelerator device 702 as a second configuration example. A pedal 72 is connected to a pedal housing 71 attached to the floor panel 2 via a pedal base 715 and a pedal connection portion 716. The driver applies a depression force Ft to a pad 73 to depress the pedal 72. In the actuator 10 of the reaction force applying device 3, the drive gear 22 rotates counterclockwise, the intermediate gear 44 rotates clockwise, and the output gear 33 rotates counterclockwise, as viewed in the drawing. As a result, the load transmission member 60 applies a reaction force Fr to the pedal 72 in the direction opposite to the depression force Ft, via an arm 78, one end of which is connected to the pedal base 715.

[0065] Thus, depending on the configuration of the accelerator device to be installed, the reaction force applying device 3 requires two types of actuators 10 with different output directions. Here, in the reducer 4 of the actuator 10, play caused by gear backlash during driving may cause abnormal noise and delays in load transmission. Therefore, in order to prevent abnormal noise and delays in load transmission, it is effective to use a scissors gear to bring the biased gear into contact with the load-receiving surface of the biasing gear.

[0066] 22, the configuration of an actuator 10 in which two sets of scissors gears are applied to the intermediate gear 44 and the output gear 33 of the reducer 4 will be described. As shown in FIG. 22, the housing 11 has a housing main body 12 made of metal or the like, and a cover (not shown) made of resin or the like. The motor 20 is accommodated in the housing main body 12, and a drive gear 22 is attached to the tip of the motor shaft 21.

[0067] The housing main body 12 is formed with an output shaft hole 121, an intermediate shaft hole 122, and a cylindrical housing portion 123. The output shaft hole 121 houses bearings 881 and 882 that rotatably support the output shaft 30. The intermediate shaft hole 122 houses bearings 883 and 884 that rotatably support the shaft 40. The cylindrical housing portion 123 is formed to extend cylindrically from the outer edge of the output shaft hole 121 toward the output gear 33. A coil-shaped return spring 50 is provided radially outside the cylindrical housing portion 123. The function of the return spring 50 will be described later with reference to Figures 25 and 26.

[0068] The intermediate gear 44 is composed of a scissors gear, which is a full-circumference gear including a biasing gear 46, an output transmission gear 48, and biasing members such as a spring 81. The biasing gear 46 and the output transmission gear 48 both mesh with the drive gear 22, which is the "mating gear." The output transmission gear 48 has a small-diameter gear portion 47 that transmits output from the intermediate gear 44 to the output gear 33. The intermediate gear 44 is rotatable around an intermediate shaft 40 supported by the housing 11.

[0069] The output gear 33 is composed of a scissors gear, which is a sector gear including a biasing gear 36, an output transmission gear 38, and a biasing member such as a spring 81. The biasing gear 36 and the output transmission gear 38 both mesh with a small diameter gear portion 47 of an intermediate gear 44, which is the "mating gear." The output gear 33 is rotatable around an output shaft 30 supported by the housing 11.

[0070] 21, in the actuator 10, the drive gear 22 rotates clockwise, the intermediate gear 44 rotates counterclockwise, and the output gear 33 rotates clockwise. As a result, the load transmission member 60 outputs a reaction force in one direction, the clockwise direction. As shown by the thick solid arrow T0 in Figure 22, the path from the drive gear 22 to the load transmission member 60 via the intermediate gear 44 and output gear 33 is the output transmission path of the actuator 10.

[0071] FIG. 23 shows the meshing state between the drive gear 22 and the intermediate gear 44. The biasing gear 46 of the intermediate gear 44, which is composed of a scissors gear, is shown by a solid line, and the output transmission gear 48 is shown by a dashed line. The output transmission gear 48 is biased in a direction (first direction) that rotates clockwise relative to the biasing gear 46 by the biasing force of a biasing member such as a spring 81. As shown by the block arrows, the biasing gear 46 biases the drive gear 22 downward in the figure, and the output transmission gear 48 biases the drive gear 22 upward in the figure. Therefore, the output transmission gear 48 always abuts against the direction of the output load of the drive gear 22 (downward in the figure).

[0072] 22 , a thick dashed arrow T1 indicates the action of the biasing gear 46 of the intermediate gear 44 and the output transmission gear 48 biasing each other via the drive gear 22. Similarly, a thick dashed arrow T2 indicates the action of the biasing gear 36 of the output gear 33 and the output transmission gear 38 biasing each other via the small diameter gear portion 47 of the intermediate gear 44.

[0073] In this way, the biasing direction of the scissors gear is determined in one direction depending on the output direction of the actuator 10. If the output direction of the actuator 10 is reversed, the biasing direction of the scissors gear must be reversed. However, if two types of biasing gears and two types of output transmission gears are set up to manufacture two types of scissors gears with opposite biasing directions, the number of gear types increases, which increases the number of management steps.

[0074] Therefore, the scissors gears of each embodiment of group A have a plurality of load receiving portions that can accommodate biasing specifications in both the first and second directions for both or either of the biasing gear 46 and the output transmission gear 48. This makes it possible to reverse the biasing direction of the scissors gears using the common gears 46 and 48 by changing the assembly position of the biasing member such as the spring 81. This avoids an increase in the number of management steps.

[0075] 24 to 26, a configuration will be described in which a scissor gear is not applied to the output gear 33, but a return spring 50 is used instead to remove backlash. The actuator 10R shown in Fig. 24 has the same configuration as that shown in Fig. 22 except for the output gear 33R.

[0076] The output gear 33R is composed of sector gears including a feed gear 34 and a return gear 35. The feed gear 34 and the return gear 35 both mesh with the small diameter gear portion 47 of the intermediate gear 44, which is the "mating gear." The output gear 33R is rotatable around the output shaft 30 supported by the housing 11. The feed gear 34 is fixed to the output shaft 30. The return gear 35 is rotatable relative to the output shaft 30.

[0077] 24 and 25 , the return spring 50 is provided radially outward of the return gear 35. One end of the return spring 50 is engaged with the housing main body 12, and the other end is engaged with the return gear 35. The return spring 50 biases the return gear 35 in the direction opposite to the rotational direction of the feed gear 34. The biasing force of the return spring 50 is transmitted from the return gear 35 to the feed gear 34 via the small diameter gear portion 47 of the intermediate gear 44.

[0078] 26 shows the meshing state between the small diameter gear portion 47 of the intermediate gear 44 and the output gear 33R. The feed gear 34 of the output gear 33R is indicated by a dashed line, and the return gear 35 is indicated by a two-dot chain line. The return biasing force Frt of the return spring 50 causes the return gear 35 to abut against the small diameter gear portion 47 of the intermediate gear 44. The small diameter gear portion 47 of the intermediate gear 44, acting on the return biasing force Frt from the return gear 35, abuts against the feed gear 34 and applies an intermediate biasing force Fmd. Because the feed gear 34 is always abutting against the small diameter gear portion 47 of the intermediate gear 44, backlash of the output gear 33R is eliminated.

[0079] In Figure 24, the thick solid arrow T0 and the thick dashed arrow T1 are the same as those in Figure 22. The thick dashed arrow T2 indicates the action of the biasing force of the return spring 50, which is transmitted from the return gear 35 of the output gear 33R to the feed gear 34 and the output shaft 30 via the small diameter gear portion 47 of the intermediate gear 44.

[0080] In this way, the same effect as a scissors gear can be obtained by configuring the output gear 33R using the biasing force of the return spring 50. As a result, compared to a configuration in which scissors gears are applied to both the intermediate gear 44 and the output gear 33 (see FIG. 22), a spring or the like for a scissors gear of the output gear 33R is not required, and the number of parts can be reduced.

[0081] [Group B: Scissors Gear with Easy Assembly] (One Embodiment) Next, with reference to FIGS. 27 to 36 , the "scissors gear with easy assembly" of Group B will be described. As one embodiment of Group B, a scissors gear with a full-circumference gear conforming to the first embodiment of Group A is shown. However, the scissors gear of Group B only needs to be able to assemble a spring 81 in at least one biasing direction. For example, as shown in FIG. 11 of the third embodiment of Group A, the output transmission gear 48 may only be formed with a spring groove 483 having a load receiving portion 487 with a first-direction biasing specification. In one embodiment of Group B, assembly of the first-direction biasing specification will be described, and reference numerals for parts not used in the first-direction biasing specification will be omitted.

[0082] The output transmission gear 48 has a second phase alignment hole 492 and a reduced diameter portion 493, which are not shown in the drawings of group A. The use thereof will be described with reference to Fig. 36. In addition, although a scissors gear with a full circumference gear is exemplified in one embodiment, the present invention can also be applied to a scissors gear with a sector gear.

[0083] The scissors gear of one embodiment of group B is assembled with an output transmission gear 48, a biasing gear 46, and one or more coil springs 81, and removes backlash of the output transmission gear 48. The output transmission gear 48 meshes with a mating gear and is rotatable about an axis O. The biasing gear 46 meshes with the mating gear together with the output transmission gear 48, and rotates together with the output transmission gear 48.

[0084] Based on the up-down direction in FIG. 33 , the surface of the biasing gear 46 facing the output transmission gear 48 is referred to as the lower surface 462, and the surface opposite the lower surface 462 is referred to as the upper surface 461. The surface of the output transmission gear 48 facing the biasing gear 46 is referred to as the upper surface 481, and the surface opposite the upper surface 481 is referred to as the lower surface 482. The lower surface 462 of the biasing gear 46 and the upper surface 481 of the output transmission gear 48, which face each other, are referred to as "facing surfaces." The spring 81 is housed in spring grooves 463, 483 recessed in the facing surfaces 462, 481 of at least one of the output transmission gear or the biasing gear. The spring 81 is compressed in the circumferential direction of the gear and biases the output transmission gear 48 to rotate in one direction relative to the biasing gear 46.

[0085] The method for assembling the scissors gear according to one embodiment is shown in the flowchart of Figure 27. This method includes steps 1 to 4, and step 2 further includes steps 2-1 to 2-3. As a premise, as shown in Figures 1 and 2 for group A, the output transmission gear 48 and the biasing gear 46 have load receiving portions 487 and 465, respectively, that receive the load of the spring 81.

[0086] At least one of the output transmission gear 48 and the biasing gear 46 (both in this embodiment) has a wall that constitutes a load receiving portion protruding from the opposing surface to form protrusions 489, 467. When assembled, the protrusions 489, 467 are inserted into the spring grooves 463, 483 of the other gear. This makes the portion where the end face of the spring 81 abuts against the load receiving portions 487, 465 larger than the radius of the spring 81, ensuring stable seating. In the opposing surface cross-sectional views of Figures 29 and 30, the cross section of the protrusion 467 of the biasing gear 46 is shown hatched.

[0087] The output transmission gear 48 and the urging gear 46 are supported on a common shaft 40, and at least one of the output transmission gear 48 and the urging gear 46 is journaled so as to be rotatable relative to the shaft 40. In this embodiment, the output transmission gear 48 is fixed to the shaft 40, i.e., supported so as not to be rotatable relative to the shaft 40, and the urging gear 46 is journaled so as to be rotatable relative to the shaft 40. In another embodiment, the urging gear 46 may be fixed to the shaft 40, and the output transmission gear 48 may be journaled so as to be rotatable relative to the shaft 40. Alternatively, both the urging gear 46 and the output transmission gear 48 may be journaled so as to be rotatable relative to the shaft 40.

[0088] Before the first step, the shaft 40 is fixed in the shaft hole 480 of the output transmission gear 48 by press-fitting or the like. In the first step, the spring 81 is set in the spring groove of the output transmission gear 48 or the biasing gear 46. In this example, the spring 81 is set in the spring groove 483 of the output transmission gear 48.

[0089] 28 , the length Lg of the spring groove 483 in the gear circumferential direction is greater than the free length Ls of the spring 81. Note that the representative value of the length Lg of the spring groove 483 in the gear circumferential direction corresponds to the arc length of the spring groove 483 at a radial position corresponding to the central axis of the spring 81. Furthermore, the width Wg of the spring groove 483 in the gear radial direction is greater than the outer diameter φs of the spring 81. This allows the spring groove 483 to be inserted without compressing the spring 81, facilitating assembly.

[0090] 33, the depth Dg of the spring groove 483 is smaller than the outer diameter φs of the spring 81, and the upper end of the spring 81 is positioned above the opposing surface 481 when inserted into the spring groove 483. This makes it easier for the spring 81 to come into contact with the load receiving portion 465 of the mating biasing gear 46.

[0091] In the second step, the biasing gear 46 is inserted into the output transmission gear 48. As shown in FIG. 28 , the output transmission gear 48 has an abutment portion 484 in a region of the opposing surface 481 that is adjacent to the spring groove 483 in the circumferential direction and extends beyond the rear wall 485 (the wall opposite the load receiving portion 487). The abutment portion 484 does not have a groove, hole, or the like formed therein. As shown in FIGS. 29 and 31 , in step 2-1, the biasing gear 46 is inserted into the output transmission gear 48 until the protrusion 467 of the biasing gear 46 abuts against the abutment portion 484 of the output transmission gear 48. The abutment of the protrusion 467 of the biasing gear 46 against the abutment portion 484 at the initial stage of assembly stabilizes the posture of the biasing gear 46.

[0092] 30 and 31 , in step 2-2, while compressing the spring 81, the urging gear 46 is rotated until the protrusion 467 of the urging gear 46 enters the spring groove 483 of the output transmission gear 48. In step 2-3, the protrusion 467 of the urging gear 46 is inserted into the spring groove 483 of the output transmission gear 48.

[0093] 32, the limitation of the deflection amount of the spring 81 (denoted as "SPG" in the figure) will be described. The spring groove 483 of the output transmission gear 48 has a rear wall 485, which is the wall opposite the load receiving portion 487, and a stepped wall 495 whose groove width in the gear radial direction decreases from the rear wall 485 side to the load receiving portion 487 side. The radial length of the protrusion 467 of the biasing gear 46 is greater than the groove width of the stepped wall 495 on the load receiving portion 487 side. The protrusion 467 is movable in the circumferential direction between the rear wall 485 and the stepped wall 495.

[0094] In the fully closed state where the protrusion 467 abuts against the rear wall 485, the spring 81 is most expanded and the amount of deflection is smallest. In the fully open state where the protrusion 467 abuts against the stepped wall 495, the spring 81 is most compressed and the amount of deflection is largest. Here, the amount of deflection of the spring 81 when fully compressed is defined as the maximum amount of deflection. In this embodiment, the amount of deflection of the spring 81 is limited to be used in a range of more than 0% and less than 80% of the maximum amount of deflection so that the spring 81 contacts the wall even in the fully closed state and a deflection margin up to full compression remains even in the fully open state.

[0095] In other words, the output transmission gear 48 and the urging gear 46 have expansion stoppers that limit the amount of relative rotation between the output transmission gear 48 and the urging gear 46 so that the amount of deflection of the spring 81 in the expansion direction becomes greater than 0% of the maximum deflection. The rear wall 485 of the output transmission gear 48 and the protrusion 467 of the urging gear 46 function as the expansion stoppers. As a result, the output transmission gear 48 and the urging gear 46 are urged even in the fully closed state, so their postures are stable.

[0096] Furthermore, the output transmission gear 48 and the urging gear 46 have compression stoppers that limit the amount of relative rotation between the output transmission gear 48 and the urging gear 46 so that the amount of deflection of the spring 81 in the compression direction is less than 80% of the maximum amount of deflection. The stepped wall 495 of the output transmission gear 48 and the protrusion 467 of the urging gear 46 function as compression stoppers. This prevents the spring 81 from being over-compressed during assembly of the spring 81 and in the inspection process after assembly.

[0097] 33 , in this embodiment, the shaft hole 460 of the biasing gear 46 is fitted to the shaft 40 so as to be rotatable relative to the shaft 40. The axial fitting length Lax, by which the biasing gear 46 is fitted to the shaft 40 in the axial direction during assembly, is greater than the protrusion amount Hp of the protrusions 467, 489. This allows the spring 81 to be compressed in step 2-2 with the biasing gear 46 journaled to the shaft 40.

[0098] FIG. 34 shows the shaft fitting configuration during assembly of a modified scissors gear. In this modified example, the output transmission gear 48 is directly supported by the shaft 40. The outer fitting wall 451 of the biasing gear 46 is fitted to the inner fitting wall 452 of the output transmission gear 48 so as to be relatively rotatable, thereby arranging the biasing gear 46 coaxially with the output transmission gear 48. In this modified example, the shaft fitting length Lax between the outer fitting wall 451 and the inner fitting wall 452 is greater than the protrusion amount Hp of the protrusions 467, 489. Therefore, the same effect as in this embodiment can be obtained. In this way, depending on the configuration of the scissors gear, the shaft fitting length Lax is defined as "the length by which one of the output transmission gear 48 or the biasing gear 46 is axially fitted to the other gear or the shaft 40 during assembly."

[0099] 35 , in the third step, a retaining member 87 is attached to the shaft 40 that has been inserted upward from the upper surface 461 of the biasing gear 46. For example, the retaining member 87, such as a snap ring, is attached to a groove formed on the outer diameter of the shaft 40.

[0100] 36 , in the fourth step, the phase of the gear teeth is aligned using an adjustment pin 449. In this embodiment, the biasing gear 46 is formed with a first phase alignment hole 491 through which the adjustment pin 449 passes. The output transmission gear 48 is formed with a second phase alignment hole 492 into which the tip of the adjustment pin 449 passing through the first phase alignment hole 491 is inserted. A tapered reduced diameter portion 493 is formed at the opening of the second phase alignment hole 492 on the opposing surface 481 side, the diameter of which decreases as it extends from the opposing surface 481 toward the back. A taper width tp, which is the difference in radius between the opening and the back of the reduced diameter portion 493, is greater than the maximum phase shift amount δmax of the gear teeth.

[0101] As the tip edge of the adjustment pin 449 is inserted deeper along the tapered shape of the reduced diameter portion 493, the biasing gear 46 and the output transmission gear 48 rotate relative to each other, making it possible to align the gear teeth from a state in which the gear teeth are out of phase. In another embodiment, a first phase alignment hole 491 may be formed in the output transmission gear 48, and a second phase alignment hole 492 may be formed in the biasing gear 46.

[0102] As described above, one embodiment of group B provides a scissors gear that is easy to assemble, with the coil spring 81 compressed in the circumferential direction of the gear. Similar to group A, this scissors gear can be applied to at least one of the output gear 33 and the intermediate gear 44 in the actuator 10 of the reaction force application device 3.

[0103] Other Embodiments In the following description of other embodiments, the reference numerals of the full gears will be used, and the reference numerals of the sector gears will be omitted.

[0104] (a) Instead of or in addition to the viewing hole 464 of the urging gear 46, a viewing hole may be formed in the output transmission gear 48. By forming a viewing hole in at least one of the output transmission gear 48 and the urging gear 46 that allows the presence or absence of the urging member at the assembly position of the urging member to be visually confirmed from the outside, incorrect assembly is prevented.

[0105] (b) The spring 81 is not limited to being accommodated across both the spring groove 463 of the biasing gear 46 and the spring groove 483 of the output transmission gear 48, but may be accommodated in the spring groove of either the biasing gear 46 or the output transmission gear 48. It is sufficient that the protrusion of one gear is inserted into the spring groove of the other gear and can receive the load of the spring 81.

[0106] (c) In one embodiment of group B in which spring 81 is used as the biasing member, the spring groove depth is less than the outer diameter of spring 81. In contrast, in the case of a scissors gear using torsion spring 82 or spiral spring 83 as the biasing member, it is preferable that the groove depth be less than the height of torsion spring 82 or spiral spring 83.

[0107] 24, the intermediate gear 44 may not be a scissors gear, and the output gear 33 may be a scissors gear. By using the biasing force of the return spring 50 and configuring the output gear 33 as a scissors gear, abnormal noise and discomfort in operation of the actuator 10 are further reduced.

[0108] (e) The scissors gear according to the present disclosure may be applied to devices other than the actuator of the reaction force application device.

[0109] As such, the present disclosure is not limited to the above-described embodiments, and can be implemented in various forms without departing from the spirit of the present disclosure.

[0110] (Disclosure of Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, with the subsequent clause referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0111] (Technical Idea 1) A scissors gear comprising: an output transmission gear (48, 38) that meshes with a mating gear and is rotatable about an axis; a biasing gear (46, 36) that meshes with the mating gear together with the output transmission gear and rotates in association with the output transmission gear; and one or more biasing members (81-89) that are provided between the output transmission gear and the biasing gear and that bias the output transmission gear to rotate relative to the biasing gear in one direction, thereby removing backlash of the output transmission gear, wherein the output transmission gear and the biasing gear each have load receiving portions (487, 488, 465, 466, 387, 388, 365, 366) that receive the load of the biasing member, and at least one of the output transmission gear or the biasing gear has a plurality of load receiving portions that receive the load of the biasing member that biases the output transmission gear to rotate relative to the biasing gear in a first direction and a second direction opposite to the first direction. (Technical Idea 2) The scissors gear according to Technical Idea 1, wherein at least one of the output transmission gear or the urging gear has a visual hole (464) that allows the presence or absence of the urging member at the assembly position of the urging member to be visually confirmed from the outside. (Technical Idea 3) The scissors gear according to Technical Idea 1 or 2, wherein the plate thickness of the output transmission gear is set to be larger than the plate thickness of the urging gear. (Technical Idea 4) The scissors gear according to any one of Technical Ideas 1 to 3, wherein the output transmission gear and the urging gear rotate about a common shaft (40, 30). (Technical Idea 5) The scissors gear according to any one of Technical Ideas 1 to 4, wherein the load receiving portions of the output transmission gear and the urging gear each have receiving surfaces (Sa1, Sa2, Sb1, Sb2) that receive the load of the urging member along a plane that passes through the rotation center of the gear.(Technical Idea 6) An actuator capable of outputting a reaction force against an external force in one direction, comprising: a housing (11); a drive source (20) having a drive gear (22) that outputs a drive force; and a reducer (4) that reduces the drive force from the drive source, wherein the reducer has an output gear (33, 33R) that can rotate around an output shaft (30) supported by the housing, and an intermediate gear (44) that meshes with the drive gear and the output gear and can rotate around an intermediate shaft (40) supported by the housing, and at least one of the output gear or the intermediate gear is constituted by a scissors gear according to any one of Technical Ideas 1 to 5. (Technical Idea 7) A reaction force imparting device capable of imparting a reaction force corresponding to the driver's depression force to a pedal (72) depressed by a driver in an accelerator device (701, 702), the reaction force imparting device comprising: an actuator (10) according to Technical Idea 6; and a load transmission member (60) that rotates integrally with the output shaft of the actuator and imparts a reaction force in the return direction of the pedal. (Technical Idea 8) A scissors gear comprising: an output transmission gear (48) that meshes with a mating gear and is rotatable about its axis; an urging gear (46) that meshes with the mating gear together with the output transmission gear and rotates accompanying the output transmission gear; and one or more coil-shaped springs (81) that are housed in at least one of spring grooves (483, 463) recessed in opposing surfaces (481, 462) that face each other on the output transmission gear and the urging gear, and that are compressed in the circumferential direction of the gear to urge the output transmission gear to rotate relative to the urging gear in one direction, thereby removing backlash of the output transmission gear, wherein the length of the spring groove in the gear circumferential direction is greater than the free length of the spring, and the width of the spring groove in the gear radial direction is greater than the outer diameter of the spring. (Technical Idea 9) A scissors gear according to Technical Idea 8, wherein the depth of the spring groove is smaller than the outer diameter of the spring.(Technical Idea 10) The output transmission gear and the urging gear each have a load receiving portion (487, 465) that receives the load of the spring, and at least one of the output transmission gear or the urging gear has a wall that forms the load receiving portion protruding from the opposing surface and forming a protrusion (489, 467) that is inserted into the spring groove of the other gear during assembly. (Technical Idea 11) The scissors gear according to Technical Idea 10, wherein the urging gear has the protrusion, and the output transmission gear has an abutment portion (484) that can abut against the protrusion of the urging gear in an initial stage of assembly, in an adjacent region on the opposing surface that extends beyond the wall (485) of the spring groove on the opposite side to the load receiving portion. (Technical Idea 12) The output transmission gear and the biasing gear are supported on a common shaft (40), and at least one of the output transmission gear or the biasing gear is journaled so as to be rotatable relative to the shaft, and the axial engagement length by which one of the output transmission gear or the biasing gear is axially engaged with the other gear or the shaft during assembly is greater than the protrusion amount of the protrusion. (Technical Idea 13) The scissors gear according to any one of Technical Ideas 8 to 12, wherein one of the output transmission gear or the urging gear has a first phase alignment hole (491) through which an adjustment pin (449) used for phasing gear teeth passes, and the other of the output transmission gear or the urging gear has a second phase alignment hole (492) through which the tip of the adjustment pin passing through the first phase alignment hole is inserted, and a tapered reduced diameter portion (493) is formed at the opening on the opposing surface side of the second phase alignment hole, the diameter of which decreases as it goes from the opposing surface to the back, and a taper width which is the difference between the radii of the opening and the back of the reduced diameter portion is greater than the maximum phase shift amount of the gear teeth. (Technical Idea 14) The scissors gear according to any one of Technical Ideas 8 to 13, wherein the output transmission gear and the urging gear have an expansion stopper which limits the amount of relative rotation between the output transmission gear and the urging gear so that the amount of deflection of the spring in the expansion direction is greater than 0% of the maximum deflection amount.(Technical Idea 15) The scissors gear according to any one of Technical Ideas 8 to 14, wherein the output transmission gear and the urging gear have compression stoppers that limit the amount of relative rotation between the output transmission gear and the urging gear so that the amount of deflection in the compression direction of the spring is less than 80% of the maximum amount of deflection. (Technical Idea 16) An actuator that can output a reaction force against an external force in one direction, comprising: a housing (11), a drive source (20) having a drive gear (22) that outputs a driving force, and a reducer (4) that reduces the speed of the driving force from the drive source, wherein the reducer has an output gear (33, 33R) that can rotate about an output shaft (30) supported by the housing, and an intermediate gear (44) that meshes with the drive gear and the output gear and can rotate about an intermediate shaft (40) supported by the housing, and at least one of the output gear and the intermediate gear is constituted by the scissors gear according to any one of Technical Ideas 8 to 15. (Technical Idea 17) A reaction force applying device capable of applying a reaction force corresponding to a pedal (72) depressed by a driver in an accelerator device (701, 702), the reaction force applying device comprising: an actuator (10) according to Technical Idea 16; and a load transmission member (60) that rotates integrally with the output shaft of the actuator and applies a reaction force in the return direction of the pedal.

[0112] The present disclosure has been described based on the embodiments. However, the present disclosure is not limited to the embodiments and structures. The present disclosure also encompasses various modifications and variations within the scope of equivalents. Furthermore, various combinations and forms, including only one element, more than one element, or less than one element, are also within the scope and spirit of the present disclosure.

Claims

1. A scissors gear comprising: an output transmission gear (48, 38) that meshes with a mating gear and is rotatable about an axis; a biasing gear (46, 36) that meshes with the mating gear together with the output transmission gear and rotates in conjunction with the output transmission gear; and one or more biasing members (81-89) that are provided between the output transmission gear and the biasing gear and that bias the output transmission gear to rotate relative to the biasing gear in one direction, thereby removing backlash of the output transmission gear, wherein the output transmission gear and the biasing gear each have load receiving portions (487, 488, 465, 466, 387, 388, 365, 366) that receive the load of the biasing member, and at least one of the output transmission gear or the biasing gear has a plurality of load receiving portions that receive the load of the biasing member that biases the output transmission gear to rotate relative to the biasing gear in a first direction and a second direction opposite to the first direction.

2. A scissors gear as described in claim 1, wherein at least one of the output transmission gear and the urging gear has a viewing hole (464) formed therein that allows the presence or absence of the urging member at the assembly position of the urging member to be visually confirmed from the outside.

3. A scissors gear according to claim 1, wherein the thickness of the output transmission gear is set to be greater than the thickness of the biasing gear.

4. A scissors gear as claimed in claim 1, wherein said output transmission gear and said biasing gear rotate about a common shaft (40, 30).

5. A scissors gear as described in claim 1, wherein the load receiving portions of the output transmission gear and the biasing gear each have a receiving surface (Sa1, Sa2, Sb1, Sb2) formed along a plane passing through the center of rotation of the gear to receive the load of the biasing member.

6. An actuator capable of outputting a reaction force against an external force in one direction, comprising: a housing (11); a drive source (20) having a drive gear (22) that outputs a drive force; and a reducer (4) that reduces the drive force from the drive source, wherein the reducer has an output gear (33, 33R) that can rotate around an output shaft (30) supported by the housing, and an intermediate gear (44) that meshes with the drive gear and the output gear and can rotate around an intermediate shaft (40) supported by the housing, and at least one of the output gear or the intermediate gear is constituted by a scissors gear as defined in any one of claims 1 to 5.

7. A reaction force imparting device capable of imparting a reaction force corresponding to the force with which a driver depresses a pedal (72) in an accelerator device (701, 702), the reaction force imparting device comprising: an actuator (10) as described in claim 6; and a load transmission member (60) that rotates integrally with the output shaft of the actuator and imparts a reaction force in the return direction of the pedal.

8. A scissors gear assembled with an output transmission gear (48) that meshes with the mating gear and is rotatable around an axis, a biasing gear (46) that meshes with the mating gear together with the output transmission gear and rotates in conjunction with the output transmission gear, and one or more coil-shaped springs (81) that are housed in at least one of spring grooves (483, 463) recessed in opposing surfaces (481, 462) that face each other on the output transmission gear and the biasing gear, and that are compressed in the circumferential direction of the gear to bias the output transmission gear to rotate relative to the biasing gear in one direction, thereby removing backlash of the output transmission gear, wherein the length of the spring groove in the gear circumferential direction is greater than the free length of the spring, and the width of the spring groove in the gear radial direction is greater than the outer diameter of the spring.

9. The scissors gear according to claim 8, wherein the depth of the spring groove is smaller than the outer diameter of the spring.

10. A scissors gear as described in claim 8, wherein the output transmission gear and the biasing gear each have a load receiving portion (487, 465) that receives the load of the spring, and at least one of the output transmission gear and the biasing gear has a wall that constitutes the load receiving portion protruding from the opposing surface and forming a protrusion (489, 467) that is inserted into the spring groove of the other gear when assembled.

11. A scissors gear as described in claim 10, wherein the biasing gear has the protrusion, and the output transmission gear has an abutment portion (484) on the opposing surface, in an adjacent circumferential region beyond the wall (485) of the spring groove opposite the load receiving portion, with which the protrusion of the biasing gear can abut in the initial stage of assembly.

12. A scissors gear as described in claim 10, wherein the output transmission gear and the biasing gear are supported on a common shaft (40), and at least one of the output transmission gear or the biasing gear is journalled so as to be rotatable relative to the shaft, and the axial engagement length by which one of the output transmission gear or the biasing gear is axially engaged with the other gear or the shaft when assembled is greater than the protrusion amount of the protrusion.

13. A scissors gear as described in claim 8, wherein one of the output transmission gear or the biasing gear is formed with a first phase alignment hole (491) through which an adjustment pin (449) used for phasing gear teeth passes, and the other of the output transmission gear or the biasing gear is formed with a second phase alignment hole (492) into which the tip of the adjustment pin that passes through the first phase alignment hole is inserted, and a tapered reduced diameter portion (493) is formed at the mouth of the second phase alignment hole on the opposing surface side, the diameter of which decreases as it goes from the opposing surface to the back, and the taper width, which is the difference in radius between the mouth and the back of the reduced diameter portion, is greater than the maximum phase shift amount of the gear teeth.

14. A scissors gear as described in claim 8, wherein the output transmission gear and the biasing gear have an expansion stopper that limits the amount of relative rotation between the output transmission gear and the biasing gear so that the amount of deflection of the spring in the expansion direction is greater than 0% of the maximum deflection.

15. A scissors gear as described in claim 8, wherein the output transmission gear and the biasing gear have a compression stopper that limits the amount of relative rotation between the output transmission gear and the biasing gear so that the amount of deflection of the spring in the compression direction is less than 80% of the maximum amount of deflection.

16. An actuator capable of outputting a reaction force against an external force in one direction, comprising: a housing (11); a drive source (20) having a drive gear (22) that outputs a drive force; and a reducer (4) that reduces the drive force from the drive source, wherein the reducer has an output gear (33, 33R) that can rotate around an output shaft (30) supported by the housing, and an intermediate gear (44) that meshes with the drive gear and the output gear and can rotate around an intermediate shaft (40) supported by the housing, and at least one of the output gear or the intermediate gear is constituted by a scissors gear as described in any one of claims 8 to 15.

17. A reaction force applying device capable of applying a reaction force corresponding to the pedal force to a pedal (72) depressed by a driver in an accelerator device (701, 702), the reaction force applying device comprising: an actuator (10) as described in claim 16; and a load transmission member (60) that rotates integrally with the output shaft of the actuator and applies a reaction force in the return direction of the pedal.

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