pericyclic transmission

Abstract

A pericyclic transmission includes at least one input shaft (58) rotatable about a rotation axis and at least one inclined bearing seat (55, 56) fixed to the input shaft, the inclined bearing seat being oriented at an inclined angle relative to the rotation axis of the input shaft. An input gear (52, 54) is mounted on each inclined bearing seat with the input gear oriented at the inclined angle and having an axis of rotation inclined by the inclination angle relative to the rotation axis of the input shaft, so that the input gear performs at least a nutation motion when the input shaft rotates. The transmission also includes intermediate gears (51, 53) meshing with the input gear, the intermediate gear having an axis of rotation coincident with the rotation axis of the input shaft. The intermediate gear is in communication with the transmission output.

Description

[Technical Field]

[0001] The present invention is particularly directed to a pericyclic transmission that provides a different power configuration to offset unbalanced moments or forces with reduced gear count versus state-of-the-art solutions. [Background technology]

[0002] FIG. 1 shows two ring gears 10 and 11 meshing with each other in a zone 15. The teeth 1 and slots 1 are shown in a fully engaged position. The number of teeth on gears 10 and 11 differs by only one or two. The angle 14 between the input shaft 12 and the output shaft 13 is slightly less than 180°. The two gears 10 and 11 have a conventional arrangement (not pericyclic) but are the basic elements of a pericyclic transmission.

[0003] A pericyclic transmission consists of four to eight bevel gears. Each pair of bevel gears has an axis angle close to 180°. The number of teeth on each pair of meshing bevel gears differs by one or two. Figure 1 shows gear pairs in a conventional (non-pericyclic) arrangement with approximately the same number of teeth and an axis angle 14 close to 180°. A pericyclic transmission uses two to four bevel gear pairs, such as those shown in Figure 1, as its basic element, and introduces pericyclic nutation motion into two or four of the bevel gears to achieve a high reduction ratio.

[0004] As shown in Figure 1, the smallest possible shaft angle difference from 180° of the meshing bevel gears is defined by the full tooth depth. In order for the teeth to engage only in one circumferential zone 15 and disengage in the opposite zone 16, the shaft angle must be at least It must be 180°-arctan{[(hole depth)*2+clearance] / (outer cone distance)}.

[0005] The clearance amount 17 must be approximately 50% or more of the total tooth depth to allow meshing between the two mating gears. The meshing conditions differ from standard bevel gear ratios 1-5. Due to the nearly 180° shaft angle, a large engagement zone 15 exists between the mating teeth. Because a difference of one or two teeth between the mating gears would result in one of the two gears rotating faster, the size of the engagement zone angle is usually selected to be less than 90°. This means that if the first gear 10 has one more tooth than the second gear 11, and tooth No. 1 of the second gear engages slot No. 1 of the first gear, tooth No. 1 disengages at one end of the engagement zone and passes one tooth of the first gear as it enters the other end of the engagement zone to then reengage with slot No. 2 of the first gear. The process of disengagement, passage of one tooth and re-engagement with the next slot not only requires sufficient clearance between the tips of the interlocking teeth, but also a sufficient angle in the disengagement zone to allow passage of one tooth without interference.

[0006] If the first gear 10 and the second gear 11 are connected to separate shafts (12 and 13) and have an axis angle less than 180°, as shown in Figure 1, the ratio is the number of teeth on the second gear 11 divided by the number of teeth on the first gear, 10 (z2 / z1). If z1 = 40 and z2 = 41, the ratio is commonly expressed as 40 x 41 or 0.9756.

[0007] In a pericyclic transmission, bevel gear pairs with approximately 180° shaft angles are utilized differently than those shown in FIG. 1. FIG. 2 shows gear 20 meshing with gear 21 in zone 22. Gear 21 is rigidly connected (or integral) with gear 23, which meshes with gear 24 in zone 19. The shaft angle between gears 20 and 21 is indicated by 26, and the shaft angle between gears 23 and 24 is indicated by 27. To provide pericyclic functionality for the transmission in FIG. 2, central shaft segment 30 is machined eccentrically under an angle of 180°-angle 26, which is equal to 180°-angle 27. Nutating gears 21 and 22 must be positioned with bearings on angled shaft segment 30 so that the pitch lines of gears 20, 21, 23, and 24 all intersect at point 50, which is also the intersection of axes 29 and 33. The bearings allow nutating gears 21 and 23 to rotate freely on angled axis 30, resulting in contact zones 22 and 19 (with a 180° rotational offset angle) rotating around the circumference of gears 20 and 24. This oscillating motion has the frequency of the input RPM. However, gears 21 and 23 only rotate one or two angular pitches per oscillating revolution, depending on the number of tooth combinations between gears 20 and 21. The number of tooth combinations between gears 23 and 24 must be different from that between gears 21 and 20 to achieve a non-zero output rotation 32 (see ratio calculation below).

[0008] The ratio calculation for a pericyclic transmission differs significantly from the typical ratio calculation for a gear transmission. The calculation is illustrated by the following example: Number of teeth: 20:z 20 =40 Number of teeth: 21:z 21 =41 Number of teeth: 23 23 =61 Number of teeth: 24 24 =60

[0009] The calculation begins with the rotationally constrained gear and its mating partner, shown in FIG. 2 as gear 20, which is rigidly connected to gearbox housing 31 and therefore constrained, and gear 21, the first gear meshing with the constrained gear. In a pericyclic transmission, the input rotation rotates an inclined central shaft 30, which holds gears 21 and 23 via bearings (no positive torque connection). When input rotation 28 rotates input shaft 29, connected to inclined shaft section 30, then instead of nearly equal high-speed rotation of gears 21 and 23, only a nutating or oscillating motion occurs. Each nutation of inclined shaft 30 will rotate gear 21 (and connected gear 23) backward by one angular pitch based on gear 21's angular pitch (Δφ1 = -360° / 41 = -8.7805°). The rotational motion between gears 23 and 24 will rotate gear 24 forward one pitch based on the pitch of gear 23 (Δφ2 = 360° / 60 = 6.0°). This means that output shaft 32 rotates Δφ1 + Δφ2 = -2.7805° for each full rotation of input shaft 28. The ratio of this pericyclic transmission is i ペリサイクリック =360° / (-2.7805°)=-129.47368. This ratio calculation follows the rule: ω 出力 =ω 入力 / i ペリサイクリック Based on.

[0010] Another way to calculate the ratio is: i ペリサイクリック =[(z 拘束 -z 第1の非拘束 ) / z 第1の非拘束 +(z 間接的に拘束 -z 第2の非拘束 ) / z 間接的に拘束 ] -1 and During the ceremony:

[0011] [Table 1]

[0012] A transmission such as that shown in FIG. 2 (see, for example, US Pat. No. 7,147,583 to Lemanski) is fully functional but produces fluctuating axial forces due to imbalances in intermediate gears 21 and 23. The rotation of gears 21 and 23 varies with the input RPM (RPM 21 / 23 =RPM 入力 / i ペリサイクリック ), the wobbling motion is fast, having the same frequency (1 / min) as the input RPM. The wobbling motion causes a fluctuating moment about axis 50 that alternates between clockwise (cw) 26 and counterclockwise (ccw) 27 directions acting on gearbox housing 31. Structural vibrations caused by imbalance are not tolerable in all applications where the input speed is above about 100 RPM.

[0013] Leading edge elimination of imbalance is achieved by connecting a second, mirror-image pericyclic unit to the first pericyclic unit, as shown in FIG. 3 (see, for example, Mathur et al., “Pericyclic Transmission Prototype: Detailed Component Design, Analysis and Fabrication,” AHS-The Vertical Flight Society, May 2019). Gear 40 is equal to gear 24, gear 41 is equal to gear 23, gear 43 is equal to gear 21, and gear 42 is equal to gear 20. Output gear 34 is positioned between gear 24 and gear 40 and is rigidly connected. Input shaft 29 is rigidly connected to shaft sections 30, 33, 35, and 44. The reaction members (gear 20 and gear 42) cannot rotate because they are connected to gearbox housing 31. Input rotation 28 is transferred to output 45, which has a reduced rotational speed.

[0014] The two units in FIG. 3 are connected to output gear 34. Gear 40 is a mirror image of gear 24. Gear pairs 41 and 43 are mirror images of gear pairs 21 and 23, and gear 42 is a mirror image of gear 20. Gear 42, like gear 20, is rigidly connected to gearbox housing 31. Shaft sections 29, 30, 33, 35, and 44 are rigidly connected as if they were one solid part. The oscillating movements of the two intermediate gear pairs 21 and 23, and 41 and 43 in FIG. 3, have opposite directions, leading to a complete cancellation of the imbalances associated with the system. Output gear 34 is rigidly connected to gear 24 and gear 40. The ratio between input shaft 29 and output gear 34 is identical to that of the transmission in FIG. 2.

[0015] Significant drawbacks of state-of-the-art solutions include the fact that the number of gears required to balance the pericyclic transmission must be doubled, and the size of the transmission increases to approximately twice the size of the transmission shown in Figure 2. Another drawback is the central location of output gear 34, which requires an additional gear to mesh with gear 34 to provide a rotating output shaft. Summary of the Invention

[0016] The present invention is directed to a pericyclic transmission that provides a different power configuration to offset unbalanced moments or forces with reduced gear count versus state-of-the-art solutions.

[0017] The pericyclic transmission includes at least one input shaft rotatable about a rotation axis and at least one inclined bearing seat fixed to the input shaft, the inclined bearing seat being oriented at an inclined angle relative to the rotation axis of the input shaft. An input gear is mounted on each inclined bearing seat with the input gear oriented at the inclined angle and having an axis of rotation inclined by the inclination angle relative to the rotation axis of the input shaft, such that the input gear performs at least a nutation motion upon rotation of the input shaft. The transmission also includes an intermediate gear meshing with the input gear, the intermediate gear having an axis of rotation coincident with the rotation axis of the input shaft. The intermediate gear is in communication with the transmission output. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 illustrates two ring gears with a one tooth difference. [Figure 2] FIG. 2 shows a conventional pericyclic transmission. [Figure 3] Figure 3 shows a conventional balanced pericyclic transmission. [Figure 4] FIG. 4 illustrates a reverse pericyclic transmission with output through the side of the transmission housing. [Figure 5] FIG. 5 illustrates a reverse pericyclic transmission in which the input and output shafts are in line. [Figure 6] Figure 6 shows an advanced reverse pericyclic transmission. [Figure 7] FIG. 7 shows the separation of the two nutation members of FIG. [Figure 8] FIG. 8 illustrates the nutating member of FIG. 7 after rotation and after changing input and output shafts. [Figure 9] FIG. 9 shows the placement of the electric motor between the two transmission halves of FIG. [Figure 10] FIG. 10 shows a transmission unit connected with a differential shaft and idlers. [Figure 11] FIG. 11 illustrates additional linkages and clutches for torque vectoring and traction control. [Figure 12] FIG. 12 shows a dual motor arrangement. DETAILED DESCRIPTION OF THE INVENTION

[0019] The terms "invention," "the invention," and "the present invention" as used herein are intended to refer broadly to all of the subject matter of this specification and any claims that follow. Statements containing these terms should not be understood to limit the subject matter described herein or to limit the meaning or scope of any claims that follow. Furthermore, this specification does not seek to describe or limit the subject matter covered by any claim in any particular part, paragraph, statement, or drawing of this application. The subject matter should be understood by reference to this entire specification, all drawings, and any claims that follow. The invention is capable of other configurations and of being practiced or carried out in various ways. It is also understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting.

[0020] Details of the invention will now be considered, by way of example only, with reference to the accompanying drawings which illustrate the invention. In the drawings, like features or components are referred to by like reference numerals. The size and relative size of certain aspects or elements may be exaggerated for clarity or for purposes of detailed description. For a better understanding and viewing of the invention, doors, casings, inner or outer guards, etc. may be omitted from the drawings.

[0021] The use of "including," "having," and "comprising," and variations thereof, herein is meant to encompass the subsequently listed items and equivalents thereof, as well as additional items. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise, and the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0022] Hereinafter, when describing the drawings, reference may be made to directions such as top, bottom, upward, downward, rearward, bottom, apex, front, rear, etc., which are referred to with respect to the drawings (as they would normally be viewed) for convenience. These directions are not intended to be interpreted literally or to limit the invention in any way. Additionally, terms such as "first," "second," "third," etc. are used herein for descriptive purposes and are not intended to denote or imply any importance or significance unless expressly stated.

[0023] The first embodiment of the inventive solution, shown in FIG. 4, reverses the concept of FIG. 2 and uses a centrally mounted intermediate gear pair 51 and 53 attached to a shaft segment 57. The gear pair consists of two identical gears, preferably straight bevel ring gears, oriented back-to-back and with cylindrical gears having teeth 59 located on their peripheries. Gears 51 and 53 can be manufactured by non-generating or generating methods. The cylindrical gear 59 on the periphery of gear pair 51 and 53 is the pericyclic transmission output. Pericyclic motion is achieved by tooth engagement between gears 52 and 51 and between gears 54 and 53 as input shaft 58 rotates angular bearing seats 55 and 56 about their respective axes, which are inclined relative to the input shaft's axis of rotation. The tooth engagement zones rotate around the circumference of input gears 52 and 54 while gears 52 and 54 oscillate without rotating.

[0024] Input gears 52 and 54 are preferably identical internal gears, preferably non-generating straight internal bevel gears mounted in mirror-image orientation, and perform a nutation motion initiated by inclined bearing seats 55 and 56. Alternatively, the internal gears may be internal gears or may have curved teeth. Gears 52 and 54 are constrained from rotation by swing pins 61 and 62 engaged in slots 63 and 64 inside transmission housing 60. Input shaft 58 is rigidly connected to shaft segments 55, 57, 56, and 65. This arrangement results in gears 52 and 54 being nutation reaction gears and gears 51, 53, and 59 being low-speed rotating output units. Input shaft 58 and segments 55, 57, 56, and 65 may be formed from a single piece of material (e.g., steel).

[0025] For example, if input gears 52 and 54 have 41 teeth and intermediate gears 51 and 53 have 40 teeth, each rotation of input shaft 58 will nutate (i.e., oscillate) but not rotate input gears 52 and 54, thereby rotating intermediate gear pair 51, 53 one pitch in the negative direction. It is preferred that the difference in the number of teeth between the input gears and the meshing intermediate gears be within the range of 1 to 5, more preferably 1 or 2.

[0026] Rotation is transmitted via cylindrical gear 59 to a second cylindrical gear outside the transmission housing 60 mounted on the output shaft (not shown). For every 40 revolutions of the input shaft 58, gear 59 rotates forward one revolution (ratio i ペリサイクリック =[1 / 40] -1 =40). i ペリサイクリック =[(z 拘束 -z 第1の非拘束 ) / z 第1の非拘束 ] -1 i ペリサイクリック =[(z 52 -z 51 ) / z 51 ] -1 =[(z 53 -z 54 ) / z 54 ] -1=[(41-40) / 40] -1 =40

[0027] Another embodiment of the invention having an output shaft 87 aligned with an input shaft 78 is shown in FIG. 5. The concept of FIG. 5 also inverts the concept of FIG. 2 by using centrally mounted intermediate gear pair 71 and 73. Intermediate gear pair 71 and 73 are connected to gearbox housing 70, while gears 72 and 74 perform a nutation motion initiated by angled bearing seats 75 and 76. Intermediate gear pair 71 and 73 are identical gears oriented back-to-back within one unit. Nutating gears 72 and 74 are also identical but mounted in a mirror-image orientation. One rotation of input shaft 78 rotates two angled bearing seats 75 and 76, achieving one complete nutation motion that rotates gears 72 and 74 by one or two angled tooth pitches (depending on the gear ratio). This rotation is transmitted to pin 80 via slots 83 and 85 and to pin 81 via slots 84 and 86. Pins 80 and 81 transmit rotation to a flange 82 which is one part of the output tube 87 .

[0028] Input shaft 78 is rigidly connected to shaft sections 75, 77, 76, and 79. For example, if gears 72 and 74 each have 41 teeth and gears 71 and 73 each have 40 teeth, each rotation of input shaft 78 rotates gears 72 and 74 one pitch. The rotation is transmitted to flange 82 of output tube 87 via pins 80 and 81. When input shaft 78 rotates 41 times, output tube 87 rotates backward one time (ratio i ペリサイクリック =-41). i ペリサイクリック =[(z 拘束 -z 第1の非拘束 ) / z 第1の非拘束 ] -1 i ペリサイクリック =[(z 71 -z 72 ) / z 72 ] -1 =[(z 73 -z 74 ) / z 74 ] -1=[(40-41) / 41] -1 =-41

[0029] A preferred embodiment of the present invention is shown in FIG. 6, which also inverts the concept of FIG. 2 by using a centrally mounted intermediate gear pair 91 and 93. Intermediate gear pair 91 and 93 are connected to gearbox housing 90, while gears 92 and 94 perform a nutation motion initiated by inclined bearing seats 95 and 96. Gears 92 and 94 engage the outer halves 102 and 103 of their face widths with intermediate gears 91 and 93, which are reaction members. Input shaft 98 is rigidly connected to shaft sections 95, 97, 96, and 99. When gears 92 and 94 perform one nutation rotation, they then both rotate by one or two angled tooth pitches (depending on the gear ratio). For example, if gears 92 and 94 have 41 teeth and gears 91 and 93 have 40 teeth, each rotation of input shaft 98 rotates gears 92 and 94 one pitch.

[0030] In FIG. 6, the rotation of gears 92 and 94 is transmitted to the output shaft via centrally mounted transfer gear pair 104 and 105, and via transfer pins 100 and 101 to flange 112 and output shaft 106. Transfer gear pair 104 and 105 are centrally positioned relative to axis 97 and are freely rotatable about axis 97 with their teeth engaging the inner halves 107 and 108 of the face widths of gears 92 and 94. The number of teeth between gears 92 and 104 and between gears 94 and 105 is identical, which achieves the transmission of the exact rotational components (excluding the oscillating components) of the motion of gears 92 and 94 to flange 112 and then to output shaft 106 via transfer pins 100 and 101. When input shaft 98 rotates 40 times, output shaft 106 rotates backwards one time (ratio i ペリサイクリック =-41). i ペリサイクリック =[(z 拘束 -z 第1の非拘束 ) / z 第1の非拘束 ] -1 i ペリサイクリック =[(z 91-z 102 ) / z 102 ] -1 =[(z 93 -z 103 ) / z 103 ] -1 =[(40-41) / 41] -1 =-41

[0031] Holes 109 and 110 provide a sufficient amount of clearance for transfer pins 100 and 101 while gear pair 104 / 105 rotates in mesh with gears 92 and 94. To maintain clearance between pins 100 and 101 and between holes 109 and 110, the number of teeth on gears 92 and 104 and 94 and 105 must be identical.

[0032] Below are some application examples for electric vehicle drives:

[0033] Electric vehicles are propelled by high-speed electric motors. These electric motors operate at RPMs three to five times higher than the RPM of the internal combustion engine. Therefore, the requirement for a reduction transmission with a very high ratio between the electric motor and the drive wheels is obvious. Pericyclic transmissions achieve the high ratios required and also allow high input speeds without the risk of scoring flank surfaces due to the fact that the relative motion between the meshing teeth is significantly lower compared to conventional high-speed cylindrical gearboxes.

[0034] A compact solution is required when a drive unit with a motor and transmission must fit between the drive wheels. The power density and compact layout of the transmission examples of the present invention shown in Figures 4, 5, and 6 appear to be well suited to the deceleration task of an electric vehicle. One requirement of the final drive unit is an output shaft on each side of the transmission. The drive shafts to the wheels must be connected to the output shaft (or output flange).

[0035] Figure 7 shows the transmission of Figure 6 cut vertically into two halves at the center. After separating the two nutation members, each half is rotated 180° about its vertical axis. The result of this rotation is shown in Figure 8. Also, the input and output shafts are reversed, so that the electric motor can be placed between the two units and the drive shafts to the wheels can be connected on the outside of the two units.

[0036] Figure 9 shows an arrangement including the installation of an electric motor 140 between the two transmission units of Figure 8. The units of Figure 9 do not have a differential function, which is required when the vehicle is driven through a curve and the outside wheels have to drive a longer distance (turn faster) than the inside wheels.

[0037] The embodiment shown in FIG. 10 solves the task of differential function between two output shafts 125, 126 by adding a connecting shaft with two pinions and an idler gear. The two reaction members 91 and 93 (FIG. 6) are not connected to the transmission housing but have teeth formed on their outside, numbered 120 and 121. Gear 121 meshes with idler pinion 122, which drives pinion 123 on shaft 124. Shaft 124 is rigidly connected to pinion 127, which meshes with gear 120. Pinions 122, 123, and 127 have the same number of teeth. This arrangement functions like a differential between output shaft 125 and output shaft 126. When a vehicle propelled by this unit is driven through a curve, the vehicle speed remains constant, but when axle 125 is connected to the wheel driving on the outside of the curve, axle 125 rotates a certain amount faster than the motor RPM, and axle 126 rotates the same amount slower than the motor RPM, to maintain vehicle speed and accommodate the different arc lengths that the two drive wheels must travel while driving through the curve.

[0038] FIG. 11 shows the addition of one coupler and two clutches for torque vectoring and traction control. Coupler 133 is installed between two half shafts 131 and 132. Additional clutches 134 and 135 can connect or disconnect shafts 131 and / or 132 to the transmission housing while coupler 133 is disconnected. This arrangement makes it possible to control the amount of torque transmitted to output shafts 125 and 126. Such a function is called "torque vectoring" or "traction control."

[0039] If motor 140 is replaced by two separately controlled motors 141 and 142 (FIG. 12), torque vectoring via electronic control of the two motors can also be achieved. One side effect of this arrangement is the fact that the two nutating gears will change their angular phase relationship (if the first motor rotates faster than the second motor), which will result in a certain imbalance of the unit.

[0040] A dual motor arrangement is shown in Figure 12. By independently controlling each motor 141, 142, torque vectoring and traction control, respectively, can be achieved without the need for a mechanical differential.

[0041] While the present invention has been described with reference to preferred embodiments, it should be understood that the invention is not limited to these particular embodiments. The present invention is intended to include modifications that would be apparent to those skilled in the art to which the present subject matter pertains without departing from the spirit and scope of the appended claims.

Claims

1. A pericyclic transmission, At least one input shaft rotatable about a rotation axis; at least one inclined bearing seat fixed to the at least one input shaft, the at least one inclined bearing seat being oriented at an oblique angle with respect to the rotation axis of the at least one input shaft; an input gear mounted on each of the at least one inclined bearing seats, the input gear being oriented at the inclination angle and having an axis of rotation inclined by the inclination angle relative to the axis of rotation of the at least one input shaft, whereby upon rotation of the at least one input shaft, the input gear performs at least a nutation motion; and two intermediate gears arranged back to back, each intermediate gear meshing with the input gear and having a rotation axis that coincides with the rotation axis of the at least one input shaft; two input gears disposed opposite each other in mirror image orientations; the intermediate gear communicates with at least one transmission output; the two input gears are constrained from rotating about their respective rotation axes, and the two intermediate gears are rotatable about their respective rotation axes; A pericyclic transmission, wherein the two intermediate gears include outer peripheries and further include a cylindrical gear formed on the outer peripheries, the cylindrical gear being the transmission output.

2. A pericyclic transmission, At least one input shaft rotatable about a rotation axis; at least one inclined bearing seat fixed to the at least one input shaft, the at least one inclined bearing seat being oriented at an oblique angle with respect to the rotation axis of the at least one input shaft; an input gear mounted on each of the at least one inclined bearing seats, the input gear being oriented at the inclination angle and having an axis of rotation inclined by the inclination angle relative to the axis of rotation of the at least one input shaft, whereby upon rotation of the at least one input shaft, the input gear performs at least a nutation motion; and two intermediate gears arranged back to back, each intermediate gear meshing with the input gear and having a rotation axis that coincides with the rotation axis of the at least one input shaft; two input gears disposed opposite each other in mirror image orientations; the intermediate gear communicates with at least one transmission output; the two input gears are rotatable about their respective rotation axes, and the two intermediate gears are constrained from rotating about their respective rotation axes; A pericyclic transmission in which rotation of the two input gears is transmitted to the output via a plurality of transfer pins extending between the two input gears and the output.

3. A pericyclic transmission, At least one input shaft rotatable about a rotation axis; at least one inclined bearing seat fixed to the at least one input shaft, the at least one inclined bearing seat being oriented at an oblique angle with respect to the rotation axis of the at least one input shaft; an input gear mounted on each of the at least one inclined bearing seats, the input gear being oriented at the inclination angle and having an axis of rotation inclined by the inclination angle relative to the axis of rotation of the at least one input shaft, whereby upon rotation of the at least one input shaft, the input gear performs at least a nutation motion; and two intermediate gears arranged back to back, each intermediate gear meshing with the input gear and having a rotation axis that coincides with the rotation axis of the at least one input shaft; two input gears positioned opposite each other in mirror image orientation; Equipped with the intermediate gear communicates with at least one transmission output; the two input gears are rotatable about their respective rotation axes, and the two intermediate gears are constrained from rotating about their respective rotation axes; a pair of rotatable transfer gears concentrically disposed within the two constrained intermediate gears; The rotation of the two input gears is transmitted to the output via a plurality of transfer pins extending between the pair of transfer gears and the output; A pericyclic transmission, wherein the two input gears and the pair of transfer gears each have the same number of teeth.

4. A pericyclic transmission, At least one input shaft rotatable about a rotation axis; at least one inclined bearing seat fixed to the at least one input shaft, the at least one inclined bearing seat being oriented at an oblique angle with respect to the rotation axis of the at least one input shaft; an input gear mounted on each of the at least one inclined bearing seats, the input gear being oriented at the inclination angle and having an axis of rotation inclined by the inclination angle relative to the axis of rotation of the at least one input shaft, whereby upon rotation of the at least one input shaft, the input gear performs at least a nutation motion; and an intermediate gear meshing with the input gear, the intermediate gear having an axis of rotation coinciding with the axis of rotation of the at least one input shaft; a first output associated with a first input shaft rotatable about the rotational axis, and a second output associated with a second input shaft rotatable about the rotational axis; the intermediate gear communicates with at least one transmission output; the first input shaft and the second input shaft, the first input shaft and the second input shaft being axially aligned with one another and disposed end-to-end; 1. A pericyclic transmission, wherein the input gear has a first number of teeth and the intermediate gear has a second number of teeth, and the first number of teeth and the second number of teeth differ by one or two.

5. 5. The transmission of claim 1, wherein the input gear comprises an internal bevel gear or an internal side gear.

6. 6. The transmission of claim 5, wherein the internal bevel gear or internal side gear comprises straight teeth.

7. 4. The transmission of claim 1, wherein the input gear has a first number of teeth and the intermediate gear has a second number of teeth, and the first number of teeth and the second number of teeth differ by one or two.

8. 5. The transmission of claim 4, comprising a first input gear and a second input gear, said first and second input gears being arranged back-to-back and axially spaced apart, said first and second input gears being rotatable.

9. 9. The transmission of claim 8, further comprising a first intermediate gear and a second intermediate gear, said first and second intermediate gears disposed opposite one another in a mirror image orientation, said first and second intermediate gears being constrained from rotation.

10. further comprising a first rotatable toothed flange integral with the first output and a second rotatable toothed flange integral with the second output, the first rotatable toothed flange being concentrically disposed within the first constrained intermediate gear, and the second rotatable toothed flange being concentrically disposed within the second constrained intermediate gear; 10. The transmission of claim 9, wherein the first rotatable toothed flange meshes with the first input gear and the second rotatable toothed flange meshes with the second input gear, whereby rotation of the first and second input gears is transmitted to the first output and the second output, respectively, via the first rotatable toothed flange and the second rotatable toothed flange, respectively.

11. 5. The transmission of claim 4, further comprising a motor connected to each of the first input shaft and the second input shaft, whereby rotation is imparted to each of the first input shaft and the second input shaft by the motor.

12. 5. The transmission of claim 4, further comprising a first motor connected to the first input shaft and a second motor connected to the second input shaft, the first motor and the second motor being independently controllable.

13. the first input shaft, the first input gear, the first intermediate gear, and the first output constitute a first transmission portion; the second input shaft, the second input gear, the second intermediate gear, and the second output constitute a second transmission portion; 10. The transmission of claim 9, wherein a motor is disposed between the first transmission portion and the second transmission portion, the motor being connected to each of the first input shaft and the second input shaft.

14. a first intermediate gear and a second intermediate gear, the first and second intermediate gears being disposed opposite each other in a mirror image orientation, the first and second intermediate gears being rotatable; 9. The transmission of claim 8, further comprising a differential mechanism connected to the first intermediate gear and the second intermediate gear, thereby providing a differential function between the first output and the second output.

15. 15. The transmission of claim 14, wherein the differential mechanism further includes a coupler and two clutches whereby the amount of torque transferred to the first output and the second output is controllable.

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