Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16H—GEARING
  • F16H1/00—Toothed gearings for conveying rotary motion
  • F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
  • F16H1/32—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear

Definitions

• the present invention relates to a planetary gear reducer, particularly a 2K-H type hypocycloid reducer.
• a cycloid reducer can obtain a large reduction ratio in one stage, and is small and lightweight, but it has many parts, has a complicated structure, and has concerns about rigidity (Patent Document 1).
• Patent Document 2 there is a reduction gear that employs a 2K-H type planetary gear mechanism (Patent Document 2).
• the planetary gear mechanism disclosed in Patent Document 2 uses two sets of internal gears and external gears that mesh with the internal gears, has high rigidity with a small number of used gears, and can significantly reduce speed with one stage.
• the present invention has been made with this in mind, and provides a speed reducer that has a small number of parts, has high rigidity, and is short in the axial direction.
• a reducer includes an input shaft having an eccentric portion, a fixed sun gear including an external gear provided coaxially with the input shaft, and the fixed sun gear a first planetary gear provided on the eccentric portion of the input shaft; and an external gear disposed coaxially with the rotation axis of the input shaft and outputting a deceleration output.
• a second planetary gear having an internal gear meshing with the driven sun gear and provided on the eccentric portion of the input shaft, the first planetary gear and the second planetary gear The gears are integrally formed in the axial direction with different gear ratios and in the same phase to form a planetary gear train.
• the speed reducer is a 2K-H type hypocycloid speed reducer, has no small driving parts such as pins, has a small number of parts, is arranged side by side in the axial direction, and has high rigidity. Since the driven sun gear that takes out the deceleration output is configured with an external gear, it is configured to be short in the axial direction.
• the planetary gear train includes a support section provided between the first planet gear and the second planet gear that are arranged in line in the axial direction, and the support section
• the support part is rotatably supported by the support part, and the support part is comprised of an inner peripheral part that forms the circumferentially inner side of the support part, and an outer peripheral part that forms the circumferential outer side of the support part, and the inner peripheral part and the outer circumferential portion are provided offset in the axial direction, and the first planetary gear is arranged substantially coaxially with the inner circumferential portion.
• the planetary gear train can be configured to be short in the axial direction.
• the support portion can be disposed close to the fixed sun gear, and the reducer itself can be configured to be short in the axial direction.
• the internal gear of the first planetary gear and the internal gear of the second planetary gear are configured based on a trochoid curve
• the first planetary gear, the fixed sun gear, and the second planetary gear are configured based on a trochoid curve.
• the difference in the number of teeth between the planetary gear and the driven sun gear is an integer of 2 or more, and the meshing ratio is 2 or more. According to this aspect, it is possible to increase the rigidity of the speed reducer and also ensure quietness.
• the present invention provides a reduction gear that has a small number of parts, has high rigidity, and is short in the axial direction.
• FIG. 1 is a perspective view (partially cutaway view) of a speed reducer according to the configuration of the present disclosure.
• FIG. 2 is a cross-sectional view of a speed reducer according to the configuration of the present disclosure. It is a rear exploded perspective view of the same reduction gear. Bearings are omitted. It is a front exploded perspective view of the same reduction gear. Bearings are omitted. It is a skeleton diagram showing the configuration of the same reduction gear. Fixed sun gear shown.
• FIG. 6(A) is a front view of the fixed sun gear.
• FIG. 6(B) is a side view of the fixed sun gear.
• FIG. 6(C) is a sectional view of the fixed sun gear. The input axis is shown.
• FIG. 6(A) is a front view of the fixed sun gear.
• FIG. 6(B) is a side view of the fixed sun gear.
• FIG. 6(C) is a sectional view of the fixed sun gear. The input axis
• FIG. 7(A) is a side view of the input shaft.
• FIG. 7(B) is a rear view of the input shaft.
• Figure 8 shows a driven sun gear.
• FIG. 8(A) is a front view of the driven sun gear.
• FIG. 8(B) is a side view of the driven sun gear.
• FIG. 8(C) is a sectional view of the driven sun gear.
• a planetary gear train is shown.
• FIG. 9(A) is a front perspective view of the planetary gear train. Mainly shows the second planetary gear.
• FIG. 9(B) is a side view of the planetary gear train.
• FIG. 9(C) is a cross-sectional view of the planetary gear train.
• FIG. 9(D) is a rear perspective view of the planetary gear train.
• 3 is a sectional view taken along line AA in FIG. 2.
• FIG. 3 is a sectional view taken along line BB in FIG.
• FIG. 1 is a perspective view (partially cutaway view) of a speed reducer W1 according to the configuration of the present disclosure.
• FIG. 2 is a sectional view of the speed reducer W1.
• FIG. 3 is a front exploded perspective view of the speed reducer W1.
• FIG. 4 is a rear exploded perspective view of the speed reducer W1.
• FIG. 5 is a skeleton diagram showing the configuration of the reducer W1. In FIGS. 3 and 4, only the main parts are shown, and bearings and the like are omitted.
• the reducer W1 is a 2K-H type hypocycloid reducer having a planetary gear mechanism.
• the speed reducer W1 mainly includes an input shaft 10, a fixed sun gear 20, a planetary gear train 30, a driven sun gear 40, and a housing 50.
• the reducer W1 is mounted on the wheel drive section of the vehicle and interposed between the motor M and the wheel hub H.
• the speed reducer W1 has an input shaft 10 and a driven sun gear 40 as an output shaft, and the rotation of the input shaft 10 is decelerated and output from the driven sun gear 40.
• the input shaft 10 is fitted into the motor M, and as the motor M rotates, the input shaft 10 rotates.
• the driven sun gear 40 is connected to a wheel hub H to which wheels (not shown) are connected, and the rotation of the driven sun gear 40 is transmitted to the wheels through the wheel hub H.
• the rotation of the motor M is decelerated by a speed reducer W1 and transmitted to the wheels, so that the wheels rotate. Either a configuration in which the input shaft 10 is directly driven as a rotating shaft on the motor M side, or a configuration in which the input shaft 10 is connected to and driven by the rotating shaft of the motor M may be used.
• the driven sun gear 40 is not only directly connected to the wheel hub H to transmit driving force, but also has a transmission shaft connected to the driven sun gear 40 and is connected to the wheel hub H via the transmission shaft.
• the structure may be such that the wheels are driven by the wheels.
• the fixed sun gear 20 includes a housing cover portion 21 and a fixed sun gear body 22.
• the housing cover part 21 and the housing 50 constitute the housing of the reducer W1.
• the housing 50 includes a cylindrical portion 51 having a substantially cylindrical shape and an end surface 52 that closes one end of the cylindrical portion 51.
• a substantially disk-shaped housing cover portion 21 is attached with bolts (not shown) so as to close an opening (an end opposite to the end surface 52) of the cylindrical portion 51.
• Each component is held in the substantially cylindrical internal space defined thereby.
• a part of the input shaft 10 is inserted through the central through hole 23 provided at the center of the housing cover part 21 and is rotatably held.
• a part of the driven sun gear 40 provided coaxially with the input shaft 10 is inserted into the central through hole 54 provided in the end surface 52 of the housing 50 and is rotatably held therein.
• FIG. 6 shows a fixed sun gear.
• FIG. 6(A) is a front view of the fixed sun gear.
• FIG. 6(B) is a side view of the fixed sun gear.
• FIG. 6(C) is a sectional view of the fixed sun gear.
• the fixed sun gear 20 consists of the housing cover part 21 and the fixed sun gear main body 22.
• the fixed sun gear 20 includes a substantially disc-shaped housing cover part 21 and a ring-shaped fixed sun gear main body 22 having a smaller diameter than the housing cover part 21, which are arranged side by side in the axial direction with their axes aligned. The two are integrally formed.
• the fixed sun gear main body 22 is provided on the side of the housing cover section 21 facing the housing 50. When the housing cover part 21 is fastened to the housing 50, the fixed sun gear body 22 is disposed inside the housing.
• a plurality of screw holes 29 are provided at equal intervals on the side edge of the housing cover portion 21 on the same circumference.
• a bolt (not shown) is inserted into the screw hole 29 and fastened to the opening of the housing 50, thereby fixing the fixed sun gear 20.
• the fixed sun gear main body 22 is an external gear in which an external gear is formed on a ring-shaped outer peripheral surface.
• the fixed sun gear main body 22 is a trochoid gear that uses a trochoid curve in its shape, and is a helical gear with tooth traces cut diagonally with respect to the axis.
• each gear has a meshing ratio of 2 or more to ensure a high meshing ratio and quietness.
• the helical gear is not essential, and a spur gear or a convex gear may be used.
• FIG. 7 shows the input shaft 10.
• FIG. 7(A) is a side view of the input shaft 10.
• FIG. 7(B) is a rear view of the input shaft 10.
• the input shaft 10 has a connecting shaft portion 11, an eccentric portion 12, a flange portion 13, and a support shaft portion 14, each of which is formed into a substantially cylindrical shape, and these are arranged in order in the axial direction. It is formed in one piece.
• the connecting shaft portion 11 constitutes one end of the input shaft 10, and the tip of the connecting shaft portion 11 protrudes from the central through hole 23 of the housing cover portion 21, and is inserted into and fixed to the motor M. Further, the base end side of the connecting shaft portion 11 is supported by the central through hole 23 via the bearing BR1, so that the input shaft 10 is rotatably supported by the fixed sun gear 20.
• the eccentric portion 12 is provided eccentrically by an eccentric amount e with respect to the central axis X, which is the rotation axis of the input shaft 10.
• the eccentric portion 12 rotates about the rotation center X1 of the eccentric portion 12 while being eccentric from the central axis X by an eccentric amount e due to the rotation of the input shaft 10.
• the flange portion 13 is provided thinly and with an enlarged diameter between the eccentric portion 12 and the support shaft portion 14, and guides the arrangement of the bearings of the eccentric portion 12 and the support shaft portion 14, and also serves as a guide when the input shaft 10 rotates. , which acts as a spacer to prevent interference and friction between parts.
• the support shaft portion 14 constitutes the other end of the input shaft 10 and is connected to the driven sun gear 40 and the rotation axis in a circular recess 48 provided at the center of one end (rear side) of the driven sun gear 40. are aligned and engaged via bearing BR3 (see Fig. 2). Thereby, the input shaft 10 and the driven sun gear 40 are connected so that their rotation axes coincide with each other and can rotate relative to each other.
• FIG. 8 shows the driven sun gear 40.
• FIG. 8(A) is a front view of the driven sun gear 40.
• FIG. 8(B) is a side view of the driven sun gear 40.
• FIG. 8(C) is a sectional view of the driven sun gear 40.
• the driven sun gear 40 is integrally formed by a cylindrical output shaft portion 41 and a substantially disc-shaped driven sun gear main body 42 whose diameter is larger than the output shaft portion 41, which are arranged with their central axes aligned in the axial direction. Become.
• the driven sun gear 40 is arranged with the driven sun gear main body 42 side facing the input shaft 10 side.
• the output shaft portion 41 is inserted into a central through hole 54 formed at the center of the end surface 52 of the housing 50, and is rotatably held via the collar C with its tip protruding outside the housing 50.
• the end surface 52 of the housing 50 has a protrusion 53 formed by extending the peripheral wall of the central through hole 54 from the surface of the end surface 52 so as to extend the central through hole 54 .
• the output shaft portion 41 is disposed in the central through hole 54 extended by the protruding portion 53, so that the driven sun gear 40 is stably and rotatably held in the housing 50.
• the collar C is used for the bearing of the output shaft portion 41 as a bearing for a location where shear load is applied and requires rigidity, a bearing may be used for the bearing.
• a wheel hub H is connected to an output shaft portion 41 protruding from the housing 50, and the rotation input from the input shaft 10 is decelerated and output from the driven sun gear 40, causing the wheel connected to the wheel hub H to rotate.
• the driven sun gear body 42 is disposed within the housing.
• a circular recess 48 for connecting to the input shaft 10 is formed in the center of the end face of the driven sun gear body 42 .
• the support shaft portion 14 of the input shaft 10 is fitted into the circular recess 48 and connected to each other so as to be rotatable around the central axis X.
• the driven sun gear main body 42 is an external gear in which an external gear is formed on a ring-shaped outer peripheral surface.
• the driven sun gear 40 rotates (rotates) about the central axis X due to the rotational input received by the driven sun gear main body 42.
• FIG. 9(A) is a front perspective view of the planetary gear train 30.
• the second planetary gear 33 is mainly shown.
• FIG. 9(B) is a side view of the planetary gear train 30.
• FIG. 9(C) is a longitudinal cross-sectional view of the planetary gear train 30.
• FIG. 9(D) is a rear perspective view of the planetary gear train 30.
• the first planetary gear 31 is mainly shown.
• the planetary gear train 30 is formed by integrally forming a first planetary gear 31, a support portion 32, and a second planetary gear 33 arranged in the axial direction.
• the first planetary gear 31 is an internal gear that has a substantially ring shape and is provided with an internal gear on its inner peripheral surface that meshes with the fixed sun gear main body 22 of the fixed sun gear 20.
• the number of teeth of the first planetary gear 31 is two or more more than the number of teeth of the fixed sun gear 20.
• the support portion 32 is configured in a substantially disk shape, is provided on the eccentric portion 12 of the input shaft 10 via a bearing BR2, and receives eccentric input when the input shaft 10 rotates.
• the second planetary gear 33 is an internal gear that has a substantially ring shape and is provided with an internal gear on its inner peripheral surface that meshes with the driven sun gear main body 42 of the driven sun gear 40.
• the number of teeth of the second planetary gear 33 is two or more more than the number of teeth of the driven sun gear 40 and is different from the number of teeth of the first planetary gear 31. That is, the first planetary gear 31 and the second planetary gear 33 are configured to have different gear ratios.
• the first planetary gear 31 is arranged on the fixed sun gear 20 side (backward) of the support part 32, and the second planetary gear 33 is arranged on the driven sun gear 40 side (front) on the opposite side from the fixed sun gear.
• the supporting portion 32 is sandwiched between the two planetary gears 31 and 33.
• Two planetary gears are provided to protrude in the axial direction from both end surfaces of the substantially disk-shaped support portion 32 .
• the gear surfaces (ring-shaped inner peripheral surfaces) of the first planetary gear 31 and the second planetary gear 33 are arranged in the same direction as the eccentric direction of the eccentric portion 12 with respect to the central axis X by the same eccentric amount e. It is installed eccentrically. That is, the first planetary gear 31 and the second planetary gear 33 are provided eccentrically and in the same phase.
• the shape of the planetary gear train 30, particularly the support portion 32, is set so that the speed reducer W1 is formed short in the axial direction.
• the support portion 32 is composed of an inner circumferential portion 32a that constitutes the circumferential inner side of the substantially disk-shaped support portion 32, and an outer circumferential portion 32b that constitutes the circumferential outer side of the support portion 32.
• the inner peripheral part 32a plays the role of being supported by the eccentric part 12, and the outer peripheral part 32b plays the role of connecting to the two planetary gears.
• the outer peripheral part 32b is axially shifted from the inner peripheral part 32a and is integrally formed with the inner peripheral part 32a. Specifically, since the outer circumferential portion 32b is configured to be offset in the axial direction from the inner circumferential portion 32a in the direction (forward) of the second planetary gear 33, the second planetary gear 33
• a substantially ring-shaped space SP1 is formed between the inner circumferential portion 32a and the first planetary gear 31, which are arranged apart from each other in the circumferential direction, and the fixed sun gear main body 22 is placed in this space SP1. That is, the first planetary gear 31, the fixed sun gear main body 22, and the inner peripheral portion 32a are located at approximately the same position in the axial direction.
• the housing cover portion 21 from which the fixed sun gear main body 22 protrudes is adjacent to the inner peripheral portion 32a.
• a housing cover portion 21, which is a housing, and a planetary gear train 30 having an inner peripheral portion 32a disposed within the housing are arranged close to each other. That is, the gap in the axial direction between the housing and the mechanical part disposed within the housing is reduced.
• the shape of the support portion 32 allows the planetary gear train 30 to be shortened in the axial direction, and the above structure also makes it possible to shorten the space in the axial direction within the housing, making it possible to shorten the speed reducer W1 in the axial direction. can.
• FIG. 10 is a cross-sectional view taken along line AA in FIG. 2. Mainly, the fixed sun gear main body 22 and the first planetary gear 31 are shown.
• FIG. 11 is a sectional view taken along line BB in FIG. Mainly, the second planetary gear 33 and the driven sun gear main body 42 are shown.
• the reducer W1 is a hypocycloid type reducer having a 2K-H type planetary gear mechanism.
• the reducer W1 includes an input shaft 10 having an eccentric portion 12, a fixed sun gear 20 consisting of an external gear coaxially provided with the input shaft 10, and a first planetary gear having an internal gear meshing with the fixed sun gear 20. 31, a driven sun gear 40 having an external gear that outputs a deceleration output, and a second planetary gear 33 having an internal gear meshing with the driven sun gear 40.
• the first planetary gear 31 and the second planetary gear 33 are integrally formed to form a planetary gear train 30.
• the first planetary gear 31 and the second planetary gear 33 are eccentrically formed in the same phase and provided in the eccentric portion 12.
• the eccentric portion 12 When the rotational input of the motor M is transmitted to the input shaft 10, the eccentric portion 12 performs an eccentric rotational movement. This eccentric rotational motion is transmitted to the first planetary gear 31 via the bearing BR2.
• the first planetary gear 31 When the fixed sun gear body 22 fixed to the housing 50 and the first planetary gear 31 mesh with each other, the first planetary gear 31 is decelerated by the gear ratio of the first planetary gear 31 and the fixed sun gear body 22, and the first planetary gear 31 is The planetary gear 31 rotates relative to the fixed sun gear main body 22 by the amount of meshing of the gears while revolving around the stationary sun gear main body 22 due to the eccentric rotation movement of the eccentric portion 12.
• the second planetary gear 33 formed integrally with the first planetary gear 31 meshes with the driven sun gear main body 42 in conjunction with the revolution movement of the first planetary gear 31, so that the second planetary gear 33 and the driven sun gear The speed is further reduced by the gear ratio with respect to the main body 42 and output.
• the second planetary gear 33 rotates while being reduced in speed by the gear ratio of the first planetary gear 31 and the fixed sun gear main body 22 relative to the input shaft 10 by the rotation of the first planetary gear 31, and the driven sun gear
• the main body 42 is further decelerated relative to the rotational speed of the second planetary gear 33 by the gear ratio of the driven sun gear main body 42 and the second planetary gear, and is output.
• the first planetary gear 31 and the second planetary gear 33 are eccentrically formed in the same phase and provided in the eccentric portion 12 .
• the reduction ratio based on the number of teeth Z1 of the fixed sun gear body 22 and the number of teeth Z2 of the first planetary gear 31 is the first reduction ratio R1, the number of teeth Z3 of the second planetary gear 33 and the number of teeth of the driven sun gear body 42. If the reduction ratio based on Z4 is the second reduction ratio R2, since they are provided in the same phase, the difference between the first reduction ratio R1 and the second reduction ratio R2 becomes the total reduction ratio i of the reduction gear W1. . Therefore, a very large reduction ratio can be obtained.
• both the first planetary gear 31 and the second planetary gear 33 are internal gears, and by providing both gears with different gear ratios, a large reduction ratio of the reduction gear W1 is realized.
• the two sets of gears of the reducer W1 each have a difference in the number of teeth of 2 or more.
• the difference in the number of teeth is 1, a larger reduction ratio can be obtained, but the amount of eccentricity must be reduced, and there is a problem that a high load is applied to the bearing provided in the eccentric part.
• the speed reducer W1 has a small number of parts, each part is approximately the same size, and is arranged side by side in the axial direction, and has high rigidity. Furthermore, a large reduction ratio can be obtained without increasing it in the circumferential direction.
• the driven sun gear 40 that takes out the deceleration output is configured with an externally toothed gear, it can be configured to be shorter in the axial direction compared to a case where it is configured with an internally toothed gear.
• the internal gear is provided so as to protrude in the axial direction from the disk-shaped base, but the external gear does not require a base and can be provided as is on the outer peripheral surface of the disk. When the face widths are the same, the internal gear can be configured to be shorter in the axial direction.
• the driven sun gear main body 42 is formed of an external gear, thereby shortening the structure inside the housing in the axial direction.
• the shape of the planetary gear train 30 is also configured to be short in the axial direction within the housing, and the reduction gear W1 is configured to be short in the axial direction as a whole. Therefore, the speed reducer W1 is configured compactly in both the radial direction and the axial direction, and can obtain a large speed reduction ratio.
• W1 Reducer
• 10 Input shaft
• 12 Eccentric part
• 20 Fixed sun gear
• 30 Planetary gear train
• 31 First planetary gear
• 32 Support part
• 32a Inner peripheral part
• 32b Outer peripheral part
• 33 Second planetary gear
• 40 Driven sun gear

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Retarders (AREA)

Priority Applications (2)

Applications Claiming Priority (1)

Publications (1)

Family

ID=89117866

Family Applications (1)

Country Status (2)

Citations (6)

• 2022
  • 2022-06-10 WO PCT/JP2022/023515 patent/WO2023238400A1/ja active Application Filing
  • 2022-06-10 JP JP2024526209A patent/JPWO2023238400A1/ja active Pending

Patent Citations (6)

Also Published As

Similar Documents

Legal Events