Dual differential overdrive reduction transmission

Abstract

A transmission having a housing (18) and at least one retractable about a first input axis (I) A1 The first input (20) is rotatable, and at least one is rotatable about the first output axis (O). A 1) A rotating first output (26). The transmission also includes a first outer gear (14) connected to and driven by the first input; a first planetary gear set comprising a first inner planetary gear (11) and a first outer planetary gear (15), wherein the inner and outer planetary gears are rigidly connected to each other and axially aligned. The first planetary gear set is rotatable (22, 24) via the first outer gear and is also rotatable (23) about the first output axis. The transmission also includes a second outer gear (16) meshing with the first outer planetary gear; and a second inner gear (12) connected to the first output and rotatable about the first output axis via the first inner planetary gear.

Description

Technical Field

[0001] This invention relates to high-reduction transmissions, and more particularly to dual differential reducers and high-reduction transmissions. Background Technology

[0002] The basic function of a high-reduction transmission is to reduce a high input RPM to a lower RPM, such as for driving the wheels of a vehicle or the rotor of a helicopter. The output RPM of this type of transmission is typically between zero and 1,000 RPM. For example, if the prime mover is an electric motor or a jet engine, the input RPM could be 20,000 RPM or higher.

[0003] Existing transmission technologies capable of achieving high deceleration include:

[0004] 1. Multi-stage gearbox using cylindrical gears

[0005] 2. A first-stage tapered worm gear reducer with a ratio of 20.

[0006] 3. Circular transmission with nutating bevel gears

[0007] 4. Cycloidal Gearbox

[0008] Multi-stage gearboxes with cylindrical gears require multiple shafts with bearings and gears. For a reduction ratio of 20, at least four stages are needed. Four reduction stages require four shafts, eight bearings, and four meshing gears. If a single stage efficiency is 99.4% (0.994...), then... 4 =0.976), so observing only the meshing of 4 gears indicates an overall efficiency of 97.6%. A four-stage cylindrical transmission requires a fairly large transmission housing.

[0009] Conical worm gear drives can be referred to as, for example, high-reduction quasi-hyperboloid (HRH) or super-reduction quasi-hyperboloid (SRH). The worm-shaped pinion typically has 1 to 5 teeth, while the ring gear typically has 27 to 75 teeth. The maximum achievable ratio is in the range of 75. Ratios higher than approximately 15 have reduced reverse drive capability. Gear sets without reverse drive capability are self-locking. Self-locking gear sets cannot be used in vehicle drivetrains or helicopter main rotor drives. Due to the large component in the width direction, conical worm gear drives also produce high slip speeds. For example, a five-tooth SRH pinion meshing with a 60-tooth ring gear produces a relative slip of 617 m / min between the side surfaces at a pinion speed of 10,000 RPM (equal to the transmission input speed). This is higher than the maximum slip expected in a sports car's quasi-hyperboloid shaft drive at speeds exceeding 125 MPH (pinion speed = 4,000 RPM). As illustrated by the example, doubling the transmission input not only reduces efficiency but also carries the risk of surface damage and premature failure.

[0010] Circular transmissions (e.g., PCT / US2020 / 059810) can achieve very high reduction speeds in the range of approximately 20 to 100 without producing high relative surface slip. The relative slip rate drops to zero when the shaft angle between the two bevel gears approaches 180°. Since the shaft angle is higher than 160° in the most common circular transmissions, the relative slip rate is not critical, even at input speeds of 20,000 RPM or higher. The disadvantages of circular transmissions are the angular bearing housings of the nutating elements and the extremely high forces exerted on the bearings at the angular bearing housings. Another potential source of problem in circular transmissions is the axial mass force generated by the nutating elements. High-speed circular transmissions require a mirrored arrangement of an even number of nutating elements, as well as precise timing and balancing of the gears.

[0011] A cycloidal transmission is a two-dimensional simulation of a circumferential transmission. For every revolution of the eccentric input shaft, the output shaft rotates one to two tooth pitches. The radial mass force of a cycloidal transmission cannot be compensated for by the arrangement of a second cycloidal disc side-by-side. Therefore, high-reduction cycloidal transmissions are only used when reducing low input speeds to extremely low output speeds.

[0012] To achieve a high ratio between 10 and 100, designers may prefer multi-stage cylindrical transmissions, which are often combined with planetary reduction gears. Multi-stage transmissions are well-known in the field and deliver reasonable power density.

[0013] There remains a need to create compact, high-reduction transmissions with easily manufactured components and predictable operating conditions. Preferably, if each of the individual parts involved in the transmission is itself considered a standard machine design component, then the prediction of durability and longevity can be improved by applying computational algorithms provided by standards such as AGMA (American Gear Manufacturers Association), ISO (International Organization for Standardization), and / or other national standards. These algorithms rely on tens of thousands of fatigue life tests and numerous application factors evaluated over decades. In safety engineering, such validated algorithms and application factors are valuable tools for engineers. Summary of the Invention

[0014] The present invention relates to a transmission comprising a housing, at least one first input rotatable about a first input axis, and at least one first output rotatable about a first output axis. The transmission further comprises a first outer gear, which is a bevel gear and is connected to and driven by the first input.

[0015] The transmission further includes a first planetary gear set comprising a first internal planetary gear and a first external planetary gear, each of which is a bevel gear. The first internal planetary gear is rigidly connected to and axially aligned with the first external planetary gear. The first planetary gear set is rotatable via a first external gear. The first internal planetary gear is rotatable about the axis of the first planetary gear, and the first external planetary gear is rotatable about the axis of the first planetary gear, thereby causing the first planetary gear set to be rotatable about the axis of the first planetary gear. Furthermore, the first planetary gear set is also rotatable about a first output axis.

[0016] The transmission of the present invention further includes a second outer gear, which is a bevel gear and meshes with a first outer planetary gear, and a second inner gear, which is a bevel gear and connected to a first output, wherein the second inner gear is rotatable via the first inner planetary gear and wherein the second inner gear is rotatable about the first output axis.

[0017] In the case of the transmission of the present invention, for a predetermined rotational speed of the first input, the rotation of the first planetary gear set about the first output axis affects the first rotational differential component of the second inner gear, and the rotation of the first planetary gear set about the first planetary gear axis affects the second rotational differential component of the second inner gear, wherein the first rotational differential component and the second rotational differential component result in the speed of the second inner gear and a first output rotational speed that is less than the predetermined input rotational speed. Attached Figure Description

[0018] Figure 1 An example of a car differential is shown.

[0019] Figure 2 Explain the dual differential transmission.

[0020] Figure 3 This describes an extended dual differential with two inputs.

[0021] Figure 4 This illustrates a dual differential with additional differential function between the two output shafts. Detailed Implementation

[0022] The terms “invention,” “the stated invention,” and “this invention” as used herein are intended to broadly refer to all subject matter of this specification and any of the following patent claims. Statements containing these terms should not be construed as limiting the subject matter described herein or limiting the meaning or scope of any appended patent claims. 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 referring to the entire specification, all drawings, and any appended claims. The invention can be constructed using other methods and can be practiced or implemented in various ways. And it should be understood that the wording and terminology used herein are for descriptive purposes and should not be considered restrictive.

[0023] The details of the invention will now be discussed with reference to the accompanying drawings, which illustrate the invention by way of example only. In the drawings, similar features or components will be referred to by similar reference numerals. For clarity or detailed explanation, the size and relative dimensions of certain aspects or elements may be exaggerated. For better understanding and ease of observation, doors, housings, outer shells, internal or external protections, etc., may have been omitted from the drawings.

[0024] The use of “comprising,” “having,” and “including,” and variations thereof, in this document, is intended to cover the items listed thereafter, their equivalents, and additional items. The use of letters or numbers to identify elements of a method or process is solely for identification purposes and does not imply an indication that the elements should be performed in a particular order. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise, and the term “and / or” includes any one and all combinations of one or more of the associated items listed.

[0025] Although references may be made below in the description of the accompanying drawings to directions such as upper, lower, upward, downward, backward, bottom, top, front, and rear, for convenience, these references are made relative to the drawings (as commonly observed). These directions are not intended to be considered literally or to limit the invention in any way. Furthermore, unless expressly stated otherwise, terms such as “first,” “second,” and “third” are used herein for descriptive purposes and are not intended to indicate or imply importance or significance.

[0026] A differential can be considered as extending a two-dimensional planetary transmission to a third dimension. Specific ratios can be achieved within the planetary gears, for example, by connecting the internal gear to the sun gear or by connecting the internal gear to the housing.

[0027] Typically, a standard differential divides the input engine torque into two ways, allowing each output of the differential to rotate at a different speed. For a description of the function of a standard differential, please refer to [link / reference needed]. Figure 1To explain, it is shown as a two-dimensional view, such as that used in a differential unit for automobiles. Input rotation is transmitted from the final drive gear 1 via bracket 8 to two planetary gears (i.e., planets) 2 and 3. Planets 2 and 3 then transmit rotation to side gears 4 and 5, which are respectively connected to output shafts 6 and 7. If output shafts 6 and 7 are connected to the vehicle's drive wheels, then in the case of straight-line travel and equal traction on both wheels, ω... 输出1 and ω 输出2 They are equal to each other and equal to the input velocity ω 输入 .

[0028] When driving through a curve, the wheels facing outwards (e.g., connected to axle 6) must travel a longer distance than the wheels facing inwards (e.g., connected to axle 7). To prevent wheel slippage while cornering, the wheels facing outwards must rotate faster, while the wheels facing inwards must rotate slower. The differential automatically adapts to this requirement. At a constant driving speed ω... 输入 In this case, shaft 7 cannot maintain the same traction torque as shaft 6 while ω 输入 Rotation requires a low speed ω 输出2 =ω 输入 -Δω. Conversely, axis 6 requires a higher speed ω. 输出1 =ω 输入 +Δω must rotate faster to maintain the same traction torque as shaft 7. Planets 2 and 3 will automatically begin rotating with or without Δω to maintain torque balance between shafts 6 and 7. The differential transmission is considered a three-dimensional version of the planetary transmission.

[0029] In the most common application in automobiles, side gears 4 and 5 are connected to the drive wheels via output shafts 6 and 7. If the two drive wheels have the same traction force when the vehicle is traveling in a straight line, and if the two wheels have the same diameter, then there will be no relative movement between gears 2, 3, 4, and 5 (Δω = 0), and the input rotation ω... 输入 The ratio of output shafts 6 and 7 is used as a transmission (ω). 输出1 =ω 输出2 =ω 输入 When navigating a curve, the wheels facing outwards (e.g., connected to axle 6) must travel a greater distance than the wheels facing inwards (e.g., connected to axle 7). The differential achieves this by the rotation of planets (in this example, gear 2 rotates at +Δω, and gear 3 at -Δω). This rotation results in an output speed of ω+Δω for the wheels facing outwards and ω-Δω for the wheels facing inwards. This maintains the vehicle speed (equivalent to ω) and adapts to curve conditions without wheel slippage or loss of traction.

[0030] in:

[0031] ω… Bracket input speed

[0032] Rotation of the Δω…Δ side gear

[0033] If all four differential gears have the same number of teeth, then the rotation of the planet is exactly Δω (for example, the upper one rotates in a clockwise (CW) direction and the lower one rotates in a counterclockwise ((CCW) direction) direction).

[0034] The solution of the present invention for low, medium or high reduction gearboxes with high power density is Figure 2 The dual differential transmission shown is symmetrical and has a high power density. The dual differential transmission preferably has eight gears symmetrically oriented, comprising a first inner planetary gear 11, a second inner planetary gear 13, a first inner side gear 10, a second inner side gear 12, a first outer planetary gear 15, a second outer planetary gear 17, a first outer side gear 14, and a second outer side gear 16, all located around a planet carrier 19, which includes a central sleeve with attached, oppositely sized posts 36, each post 36 having a threaded end for fastening a nut. Input rotation from shaft 20 to gear 14... (around axis) This will cause gears 15 and 17 to rotate around their respective pillars 36. and Because gear 16 is non-rotatably connected to housing 18 (e.g., via pin 35, as shown), rotation... (around axis) )and (around axis) The rotation of the actuating bracket 19 will be affected. (23), where the rotational amount depends on the gear tooth ratio z2 / z1. The first inner gear 10 is in Figure 2 (and Figure 3 The embodiments described are optional, but may be included for balancing and / or stability purposes.

[0035] The first internal planetary gear 11 is rigidly connected to the first external planetary gear 15, such as via a spline connection, and the second internal planetary gear 13 is rigidly connected to the second external planetary gear 17, such as via a spline connection. The connections between 11 and 15 and between 13 and 17 cause the rotation of the carrier 19 to be directly transmitted to the second internal gear 12, which acts as the output gear, as the first rotational component (first differential). and (around axis) Rotation 22 and about the axis The rotation 24) is also transmitted to gears 11 and 13, which represents the second rotational component of the second inner gear 12 (the second differential). The magnitude of this second rotation depends on the gear tooth ratio z3 / z4. With all eight gears having the same number of teeth, the ratio is infinite, meaning that the output shaft 26 (which can rotate around axis O) A1 Rotation) will not rotate (rotation) This is the result of input rotation 21. For example, if the number of teeth z2 differs from all other numbers of teeth z1, z3, and z4 by only one tooth, then the total transmission ratio... It becomes very high. Preferably, the axis and Overlap (i.e.) ).

[0036] The input rotation 21 from shaft 20 is transmitted to gears 15 and 17, resulting in rotation 22 of gear 15 and rotation 24 of gear 17. Gears 15 and 17 both mesh with gear 16. Gear 16 is rigidly connected to housing 18. The fact that gear 16 cannot rotate will result in rotation 23 of bracket 19. Gears 15 and 11, as well as gears 17 and 13, are rotationally constrained to each other. Bracket rotation 23 provides a first rotational component (first differential) to the second inner gear 12. Rotations 22 and 24 add a second rotational component (second differential) to the second inner gear 12. If all eight involved bevel gears have the same number of teeth, then output rotation 25 will be zero. This can be interpreted as, for example, a 90° rotation of bracket 19. This will cause gears 15 and 17 to rotate 90° in directions 22 and 24. Output gear 12 will therefore receive a 90° rotation from the bracket. and 90° rotation from gears 11 and 13 (In the opposite direction), and therefore not independent of the input rotation 21. Although this embodiment may seem to have no practical significance, the example is used to illustrate the function of a dual differential transmission. In the example, the ratio is...

[0037] The equations for the ratios are derived by using individual tooth counts, resulting in various possible ratios for tooth count variations of gears 14 / 16 versus 15 / 17 and 10 / 12 versus 11 / 13.

[0038]

[0039] or:

[0040]

[0041]

[0042] Insert (2) into (4):

[0043] or:

[0044] Insert (6) into (3):

[0045] Insert (6) into (2):

[0046] Insert (8) into (7):

[0047] Rearrange:

[0048] in:

[0049] z1… Number of teeth of gears 14 and 16

[0050] z2… Number of teeth of gears 15 and 17

[0051] z3… Number of teeth of gear 10 and gear 12

[0052] z4… Number of teeth of gears 11 and 13

[0053] …rotation angle of gear 14

[0054] …rotation angle of bracket 19

[0055] …Gear 15 (and in negative) The rotation angle of gear 17 in the direction

[0056] …rotation angle of gear 12 (and output shaft 26)

[0057] R…the ratio of input speed to output speed

[0058] The following four examples demonstrate the extremely high ratio range achievable with dual differentials, using different gear combinations, without significantly altering the transmission dimensions:

[0059] Example 1:

[0060] z1 = 40; z2 = 39; z3 = 40; z4 = 40; ratio R = -78.000

[0061] Example 2:

[0062] z1 = 40; z2 = 41; z3 = 40; z4 = 40; ratio R = 82.000

[0063] Example 3:

[0064] z1 = 45; z2 = 50; z3 = 40; z4 = 40; ratio R = 20.000

[0065] Example 4:

[0066] z1 = 30; z2 = 50; z3 = 40; z4 = 40; ratio R = 5.000

[0067] The expansion of the dual differential transmission function in Figure 3 The image shows a two-dimensional view of an extended dual differential with two input shafts. (This is illustrated by comparing it with...) Figure 2 In comparison, it has already been Figure 3 Gears 30 and 31 and shaft 32 have been added. In the extended arrangement, the second outer gear 16 is not restricted to rotation of the housing 18, but gear 16 is now connected to a first cylindrical gear 30, which is arranged to rotate relative to the housing 18 and meshes with a second cylindrical gear (i.e., pinion), the second cylindrical gear 31 being connected to a shaft that can rotate about the input axis. A rotating second input shaft 32. This possibility of a second input allows for multiple input speed combinations of two different prime movers (e.g., electric motors) with different speed and torque characteristics. For example, one motor could be a high-torque, low-speed motor that operates at a constant speed signal without speed regulation. Then, for example, if zero RPM output is required, the second motor will rotate in the opposite direction. For example, in the case of rapid acceleration to the vehicle's cruising speed, the second motor is first turned off, using the kinetic energy stored in the differential gears and carriers for vehicle acceleration. A few seconds later, for example, when the vehicle reaches half its cruising speed, the second motor is now rotating in the direction of actuation. During the first phase of acceleration, a significant amount of energy is extracted from the battery of a conventional electric vehicle. The extended dual differential allows for the storage of kinetic energy during gentle driving as well as during deceleration and braking actions.

[0068] The second outer gear 16 is connected to the first cylindrical gear 30, which is rotatably arranged in the housing 18 and meshes with the second cylindrical gear 31, which is connected to the second input shaft 32. In the case of two input shafts, no single ratio produces the following relationship between the output rotation and the two input rotations:

[0069]

[0070] or:

[0071]

[0072]

[0073] Insert (12) into (14):

[0074] or:

[0075] Insert (16) into (13):

[0076] Insert (16) into (12):

[0077] Insert (18) into (17):

[0078] Second input rotation:

[0079] in:

[0080] z5… Gear 30 number of teeth

[0081] The number of teeth on gear 31 (z6...)

[0082] …rotation angles of gears 16 and 30

[0083] By rotating different inputs Applying equation (19) can lead to two special cases. Case 1: Output speed (rotation angle) The speed (rotation angle) of gear 16 is equal to that of gear 16. In this case, the output rotates. Equal to input rotation This results in a ratio R = 1.00:

[0084] Will insert

[0085] (21) Solve

[0086] Or simplified:

[0087] The result is: R = 1.00 (24)

[0088] In case 2, input rotation The value is zero, which simplifies equation (19), and it becomes equal to equation (9):

[0089] Will Insert (19):

[0090] Eliminate zero terms:

[0091] Equation (9) is based on the fact that gear 16 is rigidly connected to the existing condition. The transmission housing, in turn, proves that equation (19) is conclusive.

[0092] The gears in a dual differential can be straight bevel gears, spiral bevel gears, or planar gears with cylindrical gears. At high input speeds, ground spiral bevel gears deliver the highest efficiency, lowest noise emissions, and high load-bearing capacity. The axial forces in a dual differential are similar to those in a car differential with straight bevel gears.

[0093] Because gears with quasi-hyperboloid offsets are preferably not used, relative surface slip has no component in the face width direction and consists only of profile slip. A spiral bevel gear set with a ratio close to 1.0 and an outer diameter of 120 mm (typical for a dual differential transmission in a car) exhibits a maximum relative profile slip of approximately 84 m / min at 1,000 RPM. The relative speed between the two fastest gears (14 and 15) in a dual differential transmission is only about 50% of the input speed. Equation 8, If z1 = 40 and z2 = 41, the speed of delivery gear 15 is 48.8% of the input speed. Therefore, in this case, the relative speed between gear 14 and gear 15 is This means that the relative speed between the fastest gears in a dual differential transmission is typically only about half the input speed. If the input speed is 10,000 RPM, then the dual differential would only achieve 10.84 m / min × 0.512 = 430.08 m / min. Compared to a standard spiral bevel gear transmission, the dual differential transmission has only 51.2% of the slip speed in this case. Table 1 provides an overview of the slip speeds and efficiencies of the different types of transmissions mentioned. The slip speed and efficiency calculations on which Table 1 is based can be determined using commercially available software, such as UNICAL. TM Bevel gear analysis and optimization software.

[0094] Table 1

[0095]

[0096] The comparison in Table 1 clearly shows the advantages of dual differential reduction over other types of reduction gears. Lower relative surface slip indicates less friction, resulting in higher transmission efficiency. Less friction also leads to less heat generation within the transmission. The calculated gear efficiencies are shown in the last column of Table 1. At a ratio of 80 and a transmission input speed of 10,000 RPM, a high gear efficiency of 98.8% has not been reported in prior art transmissions.

[0097] The extended dual differential allows for a variety of applications due to the second input (Input 2). For example, if Input 2 is connected to a low-speed, high-torque motor rotating clockwise (CW) at 1,500 RPM without speed change, and Input 1 is connected to a variable-speed, low-torque motor rotating counterclockwise (CCW), it is possible to select the speed of Input 1 (e.g., -9,500 RPM) so that the output speed is zero RPM. This example is based on the following tooth count:

[0098] z1 = 45;

[0099] z2 = 50;

[0100] z3 = 40;

[0101] z4 = 40;

[0102] z5 = 60;

[0103] z6 = 20;

[0104] The speed of input 2 (axis 32) is n6 = 1,500 RPM CW (equal to positive). The first deceleration is z6 / z5 = 20 / 60, and the speed of gear 30 is n5 = 500 RPM. The speed of the output shaft is n4 = 0.

[0105] If we use the rotational speed n, expressed in RPM, instead of the angle... Equation (19) also works:

[0106] n4=(n1+n5) / 2·[1-z1 / z2·z4 / z3]+n5·z1 / z2·z4 / z3

[0107] It becomes: 0 = (n1 + 500) / 2 * [1 - 45 / 50 * 40 / 40] + 500 * 45 / 50 * 40 / 40

[0108] Or: 0 = (n1 / 2 + 250) * 0.1 + 450

[0109] We get: n1 = -9,500 RPM

[0110] A practical application of this example is a vehicle idling at a traffic light at an intersection. When the light turns green, n1 can decrease from -9,500 RPM to zero to accelerate the vehicle from 0 MPH to 35 MPH. During the acceleration cycle, the kinetic energy of the dual differential assembly with gears 10, 11, 12, 13, 14, 15, 16, and 17, as well as the bracket 19 and the motor connected to input 1, is used to deliver most of the acceleration energy. Driving faster than 35 MPH will simply require rotating the input in the opposite direction. At a vehicle speed of 70 MPH, the speed of input 1 will reach n1 = +9,500 RPM. Depending on the vehicle's duty cycle (highway or city driving), the low-speed motor can be turned off and the clutch (not shown) applied to lock input 2. In this case, the transmission motor connected to input 1 will deliver all the energy required for, for example, light city driving.

[0111] When attempting to continuously reverse-charge a battery with sudden bursts of regenerative energy, electrical efficiency becomes extremely low, and the battery's chemical capacity to absorb large amounts of energy in just a few seconds is limited. For example, a mid-size sedan traveling at 35 MPH has approximately 0.4 kWh of kinetic energy. Rapidly slowing down before a traffic light that has just turned red requires recovering 0.4 kWh in about 2 to 3 seconds. Therefore, no more than 0.10 to 0.15 kWh may be recharged into the battery, while 0.25 kWh may be converted into heat in the brake discs or electronic vehicle control modules. A dual differential, including the motor on input 1, can store approximately 0.24 kWh with an efficiency of about 96%, meaning that 0.23 kWh is provided in the form of the dual differentials rotating when the vehicle comes to a complete stop at a red light. This energy is only used a few minutes later to accelerate the vehicle after the traffic light turns green. Short-term energy storage is not efficiently achievable with current battery technology. The dual differential concept, in turn, allows for a reduction in battery size while maintaining the same range capacity.

[0112] The combination of the two input speeds enables a wide range of possibilities for using a dual differential transmission under different driving conditions by achieving optimal efficiency of the electric motor and transmission. Another advantage is the ease of energy storage in the fast-spinning differential bracket unit, which will support the vehicle's battery, especially when high energy bursts are required, such as accelerating a heavy-duty truck from 0 MPH to 30 MPH. Compared to an internal combustion engine, an electric motor requires very little energy to operate unloaded without any external resistance.

[0113] A dual differential with two inputs can also be used to harvest energy from the electric motor and the internal combustion engine and transfer it to the drive wheels of a hybrid vehicle. In this arrangement, the optimal speed combination for each of the two prime movers can be found, which also allows for the elimination of any additional transmission in the hybrid vehicle.

[0114] As previously mentioned, the function of a dual differential does not require the first inner gear 10. It is used to make the transmission symmetrical, and it is expected that gear 10 will help maintain equal torque on gears 11 and 13 under conditions of deformation of the large gears and transmission housing (under high loads). If symmetry and balance are not an issue, then gear 10, as well as the additional gears 13 and / or 17, can be eliminated to simplify the dual differential transmission to include seven, six, or even five gears, thereby reducing manufacturing costs.

[0115] In order to allow the dual differential transmission of the present invention to be placed between the wheels of the driveshaft in a vehicle, Figure 4 Additional embodiments are shown, illustrating Figure 2 A two-dimensional view of a modified version of the dual differential. Figure 4 The transmission has an additional differential function between two output shafts 26 and 41. Output shaft 26 is located on the right side of the transmission housing, and the additional output shaft 41 can rotate around the output axis. Rotate, leaving the transmission housing on the left. Gear 10, which is not needed for normal dual differential function, has been eliminated, and shaft 41 now acts as the main transmission shaft. Figure 2 The function of the central axis 26. Figure 2 The first inner gear 12 in Figure 4 The central gear has been replaced by gear 40. Gear 40 is hollow to create space for the placement of four differential gears 42, 43, 44, and 45. Gears 42 and 43 are planetary gears, held in place relative to gear 40 by pins 46. Pins 46 connect to gear 40, which is the gear with the final output speed. Gears 44 and 45 are side gears. Output shaft 26 connects to side gear 44, and output shaft 41 connects to side gear 45. Figure 4 The design will achieve [interaction / cooperation] between the two output shafts 26 and 41. Figure 1 The same differential function is explained for output shafts 7 and 6. The end cap 47 encloses the differential inside gear 40 and serves as a radial sleeve bearing for shaft 26 and a thrust sleeve bearing for gear 44. The wall of the cavity in gear 40 serves as a thrust sleeve bearing for gears 42 and 43. Preferably, the input shaft axis... and output axis They are parallel, and more preferably coincident (i.e., ).

[0116] Figure 4 The transmission in this system includes an additional differential, which adapts to different wheel speeds when the vehicle is traveling, for example, while cornering. Similar to... Figure 1 The differential shown is integrated into gear 40. Figure 4The transmission has an output shaft 26 that can be connected to the right wheel and an output shaft 41 that can be connected to the left wheel. The input shaft 20 remains on the left side of the transmission. If the input shaft 20 is connected to an electric motor with a hollow shaft, then the transmission and the drive electric motor of the present invention can be aligned with the drive shaft of the vehicle. This means that the output shaft 26 can be connected to the right drive wheel via a first drive shaft and a constant velocity (CV) joint, and the output shaft 41 can be connected to the left drive wheel via a second drive shaft and a CV joint.

[0117] While the invention has been described with reference to preferred embodiments, it should be understood that the invention is not limited to its details. The invention is intended to include modifications that will be obvious to those skilled in the art without departing from the spirit and scope of the appended claims.

Claims

1. A transmission comprising a housing (18), at least one first input (21) and at least one first output (26), the transmission further comprising a double differential, the double differential having: a first outer side gear (14) that is a bevel gear and is connected to and drivable by the first input, a first planetary gear set comprising a first inner planetary gear (11) and a first outer planetary gear (15), each of the first inner planetary gear and the first outer planetary gear being a bevel gear, wherein the first inner planetary gear is rigidly connected to and axially aligned with the first outer planetary gear, the first planetary gear set being rotatable via the first outer side gear (14), a second outer side gear (16) that is a bevel gear and is in mesh with the first outer planetary gear (15), a second inner side gear (12; 40) that is a bevel gear and is connected to the first output (26), the second inner side gear being rotatable via the first inner planetary gear (11), The first input is rotatable about a first input axis (I A1 ) The first output is rotatable about a first output axis (O A1 ) The first inner planet gears (11) are rotatable about a first planet gear axis (S A1 ) and the first outer planet gears (15) are rotatable about the first planet gear axis (S A1 ), thereby causing the first planet gear set to be rotatable about the first planet gear axis (S A1 ), The first planetary gear set can also rotate about the first output axis (O A1 ) The second inner side gear is rotatable about the first output axis (O A1 ) a second planetary gear set disposed opposite the first planetary gear set, the second planetary gear set comprising: a second inner planetary gear (13) and a second outer planetary gear (17), each of the second inner planetary gear (13) and the second outer planetary gear (17) being a bevel gear, wherein the second inner planetary gear (13) is rigidly connected to and axially aligned with the second outer planetary gear (17), the second planetary gear set being rotatable via the first outer side gear (14), The second inner planet gears (13) are rotatable about a second planet gear axis (S A2 ) and the second outer planet gears (17) are rotatable about the second planet gear axis (S A2 ), thereby causing the second planet gear set to be rotatable about the second planet gear axis (S A2 ), The second planetary gear set can also rotate about the first output axis (O A1 ) wherein, the double differential being symmetrical by the following means, the double differential having a first inner side gear (10) that is a bevel gear and is also rotatable via the first inner planetary gear (11), and wherein, in an axial cross-sectional view, pitch lines of bevel gear connections of the first outer side gear (14) and first outer planetary gear (15), pitch lines of bevel gear connections of the first outer planetary gear (15) and the second outer side gear (16), and pitch lines of bevel gear connections of the first inner planetary gear (11) and the second inner side gear (12) cross at intersections of rotational axes of the first outer side gear (14) and the first inner planetary gear (11).

2. The transmission of claim 1, wherein the first input axis (I A1 ) and the first output axis (O A1 ) are parallel to each other.

3. The transmission of claim 2, wherein the first input axis (I A1 ) and the first output axis (O A1 ) coincide with each other.

4. The transmission of claim 1, wherein the second outer side gear (16) is non-rotatable.

5. The transmission of claim 1, wherein for a predetermined rotational speed of the first input: The rotation of said first planetary gear set around said first output axis (O A1 ) affects a first rotational differential component of said second inner side gear (12), and The rotation of said first planetary gear set around said first planetary gear axis (S A1 ) affects a second rotational differential component of said second inner side gear (12), wherein the first rotational differential component and the second rotational differential component result in a second inner side gear speed and a first output rotational speed that is less than the predetermined rotational speed of the first input.

6. The transmission of claim 1, wherein the first planetary gear axis (S A1 ) and the second planetary gear axis (S A2 ) coincide with each other.​​ 7. The transmission of claim 1, further comprising: a second input rotatable about a second input axis (I A2 ) comprising a first cylindrical gear rotatable about the second input axis (I A2 ), The transmission further comprises a second cylindrical gear rotatable about the first output axis (O A1 ) and meshing with the first cylindrical gear, the second cylindrical gear being rigidly connected to the second outer gear (16).

8. The transmission of claim 1, further comprising: The second, inner side gear (12) has an interior space and includes a differential mechanism that includes a plurality of bevel gears located within the interior space.

9. The transmission of claim 8, further comprising a second output rotatable about a second output axis (O A2 ) and wherein the first and second outputs are connected to the second inboard gear (12) and the differential mechanism.

10. The transmission of claim 9, wherein the first output and the second output extend in opposite directions.

11. The transmission of claim 9, wherein the second output extends into and through the first input.

12. A method of reducing the rotational speed of an input shaft (20) in a transmission, the method being applied to the transmission of claim 1.

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