VEHICLE SEAT ADJUSTMENT MECHANISM AND SEAT RAIL ASSEMBLY

Abstract

A vehicle seat adjustment mechanism comprising: a gear box (400); a first gear (80n, 80p) received in the gear box (400) and rotatable relative to the gear box (400) about a first axis; a spindle screw (56j) selected from the group consisting of: a first spindle screw (56j) with trapezoidal thread (66j) and defined by Tr 8×3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread pitch), a second spindle screw (56j) with trapezoidal thread (66j) and defined by Tr 9×3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread pitch), a third spindle screw (56j) with trapezoidal thread (66j) and defined by Tr 11×4 (P2) (11 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead), and a fourth spindle screw (56j) with trapezoidal thread (66j) and defined by Tr 12×4 (P2) (12 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead); and a second gear (86n, 86p) received in the gear box (400) and rotatable relative to the gear box (400) about a second axis perpendicular to the first axis, the first gear (80n, 80p) and the second gear (86n, 86p) being in meshing engagement with each other, and the second gear (86n, 86p) having a spindle nut having an internal thread (90) adapted to the selection of the spindle screw (56k), the spindle screw (56j) being in meshing engagement with the internal thread (90) of the second gear (86n, 86p) and extending through the second gear (86n, 86p) along the second axis; wherein the vehicle seat adjustment mechanism further comprises a motor driving the first gear (80n, 80p), the motor having a maximum rotational speed of 5,500 revolutions per minute, wherein the gear box (400), the first gear (80n, 80p) and the second gear (86n, 86p) are configured to move along the second axis at one of: (i) a comfort speed with a linear adjustment speed in the range of 17 mm / s to 22 mm / s, (ii) a high speed with a linear adjustment speed in the range of 55 mm / s to 60 mm / s, or (iii) a very high speed with a linear adjustment speed in the range of 85 mm / s to 90 mm / s, wherein a gear ratio of the first gear (8on, 80p) to the second gear (86n, 86p) is selected from the group consisting of: 8.5, 7.5, 6.5, 5.667, 5.333, 4.667, 4.333, 3.667, 3.333, 3.25, 3.2, 2.833, 2.8, 2.75, 2.6, 2.4 and 2.2, and wherein the spindle screw (56j) has a minimum axial strength of 19 kN.

Description

AREA

[0001] The present disclosure relates generally to gear drive housing assemblies for vehicle seat adjusters, and more particularly to a bidirectionally self-centering housing for an orthogonal gear drive (e.g., of the wrap-around or helical type) used in adjusting the fore-and-aft position of a vehicle seat. BACKGROUND

[0002] This section provides background information related to the present disclosure and is not necessarily prior art.

[0003] Vehicles such as automobiles are typically equipped with seat adjustment mechanisms that can primarily adjust the height, inclination, and / or fore / aft position of the driver and / or front passenger seat to accommodate occupants of different sizes and heights and provide a comfortable seating position that meets the occupant's preferences. Such seat adjusters can be operated manually or externally. Examples of seat adjustment mechanisms can be found in documents DE 10 2021 204 240 A1 and DE 10 2019 125 196 A1.

[0004] Externally powered seat adjusters are driven by electric motors, and their size is directly related to the torque they must provide to produce the required movement. Therefore, if a relatively high reduction ratio can be achieved in a very limited space, smaller and faster electric motors can be used to provide the same level of mechanical power required for the required function. High-speed electric motors capable of delivering a certain level of torque, used in certain applications, require a limited reduction ratio, but within a very compact dimensional space.

[0005] Electric motor-driven adjusters offer several advantages over manual adjusters. User comfort can be improved. Electric motor-driven adjusters also provide an electrical interface that lends itself to automation, for example, through control by a vehicle's control unit, which can automatically control the motor to move the seat to a desired position. Despite the advantages offered by electric motor-driven adjusters, packaging is a problem for many seats.

[0006] Typically, an externally powered seat length adjuster is actuated by an occupant-controlled switch and includes a bidirectional electric motor mounted centrally or intermediary between the pair of track assemblies of the vehicle seat, which rotates two flexible drive shafts extending outwardly from the motor to two gear box blocks fixedly mounted within each upper or inner track assembly. Each gear box block contains a worm-and-worm gear or worm-and-spiral gear drive assembly, with the drive member actuated by the flexible drive shaft and the driven member being a single-piece assembly with an internal threaded spindle nut.

[0007] Each spindle drive assembly includes the aforementioned rotatable spindle nut, which threadably receives and is secured to a lead screw extending longitudinally along the lower or outer track assembly. Through these two drives, the rotary motion of the electric motor is orthogonally translated to move the upper tracks linearly back and forth relative to the lower tracks along the spindle screw axes. The vehicle seat is mounted to a frame supported by the pair of movable upper tracks of the seat, which are arranged parallel to each other, while the pair of lower tracks are attached to the vehicle body. Typically, two drive shafts, gear boxes, lead screws, and drive nuts are used in an externally driven length adjuster drive, one set for each seat track assembly, driven by a single bidirectional electric motor. SUMMARY

[0008] The invention is defined by the independent claims. The dependent claims indicate preferred embodiments. This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.

[0009] A gear box for a vehicle seat adjustment mechanism is provided according to the principles of the present disclosure. The gear box includes a first portion and a second portion. The first portion includes a first body. The first body defines a first longitudinal recess and a first circumferential recess in fluid communication with the first longitudinal recess. The first body includes a first curved surface. The first curved surface is concave. The second portion includes a second body. The second body defines a second longitudinal recess and a second circumferential recess in fluid communication with the second longitudinal recess. The second body includes a second curved surface. The second curved surface is convex. The second curved surface has an equal and opposite curvature compared to the first curved surface.In an assembled configuration, the first curved surface is in contact with the second curved surface. In the assembled configuration, the first longitudinal recess communicates with the second longitudinal recess to define a longitudinal passage. In the assembled configuration, the first circumferential recess communicates with the second circumferential recess to define a circumferential receptacle.

[0010] In one implementation, the first curved surface and the second curved surface both define (i) a portion of an ellipsoidal surface, (ii) a portion of a conical surface, or (iii) a portion of a spherical surface.

[0011] In one implementation, the first curved surface and the second curved surface both define a portion of an ellipsoidal surface. The ellipsoidal surface has a first radius in a range of 190 mm to 200 mm and a second radius in a range of 240 mm to 250 mm.

[0012] In one implementation, the first curved surface and the second curved surface both define a portion of a conical surface. The conical surface defines an average opening angle in a range of 165° to 172°.

[0013] In one implementation, the first curved surface and the second curved surface both define a portion of a spherical surface. The spherical surface has a radius in a range of 190 mm to 200 mm.

[0014] In one implementation, one of the first portion and the second portion includes a frustoconical protrusion extending from a respective one of the first curved surface and the second curved surface. The other of the first portion and the second portion includes a frustoconical receptacle defined by a respective one of the first curved surface and the second curved surface. In the assembled configuration, the frustoconical receptacle receives the frustoconical protrusion.

[0015] In one implementation, one of the first portion and the second portion further includes an annular protrusion extending from the respective one of the first curved surface and the second curved surface. The annular protrusion is disposed about a base of the frustoconical protrusion. The annular protrusion is coaxial with the frustoconical protrusion. The other of the first portion and the second portion further includes an annular recess defined by a respective one of the first curved surface and the second curved surface. The annular recess is coaxial with the frustoconical receptacle. In the assembled configuration, the annular recess receives the annular protrusion.

[0016] In one implementation, the frustoconical projection includes a first frustoconical projection and a second frustoconical projection. The frustoconical receptacle includes a first frustoconical receptacle and a second frustoconical receptacle. The annular projection includes a first annular projection and a second annular projection. The annular recess includes a first annular recess and a second annular recess.

[0017] In one implementation, the gear box further includes an elastic layer. The elastic layer is disposed on at least one of the first curved surface and the second curved surface.

[0018] In one implementation, one of the first portion and the second portion includes an integrated rivet. The integrated rivet extends from a respective one of the first curved surface and the second curved surface. The other of the first portion and the second portion includes an opening defined in a respective one of the first curved surface and the second curved surface, the opening configured to receive a portion of the integrated rivet.

[0019] In one implementation, the gear box further includes a plurality of fasteners. The plurality of fasteners are configured to couple the first portion and the second portion together.

[0020] In one implementation, the gear box is configured to receive at least a portion of a cross-axis gear system and a lead screw. The cross-axis gear system includes a first gear operatively connected to a second gear. The second gear is operatively connected to the lead screw.

[0021] In one implementation, the gear box is a universal gear box. The gear system is configured to operate at one of the following: (i) a comfort speed has a linear adjustment speed in the range of 17 mm / s to 22 mm / s, (ii) a high speed has a linear adjustment speed in the range of 55 mm / s to 60 mm / s, or (iii) a very high speed has a linear adjustment speed in the range of 85 mm / s to 90 mm / s.

[0022] In one implementation, the first gear is a cylindrical worm gear and the second gear is one of a spiral gear or a single enveloping worm gear.

[0023] In another form, the present disclosure provides another vehicle seat adjuster assembly that includes a gear box, a gear system, and a lead screw. The gear box assembly includes a first portion and a second portion. The first portion includes a first body. The first body defines a first longitudinal recess and a first circumferential recess in fluid communication with the first longitudinal recess. The first body includes a first curved surface. The first curved surface is concave. The second portion includes a second body. The second body defines a second longitudinal recess and a second circumferential recess. The second body includes a second curved surface. The second longitudinal recess cooperates with the first longitudinal recess to define a longitudinal passageway. The second circumferential recess cooperates with the first circumferential recess to define a circumferential receptacle.The second curved surface is convex, has an equal and opposite curvature compared to the first curved surface, and is in contact with the first curved surface. The gear system includes a first gear and a second gear. The first gear is at least partially disposed within the circumferential receptacle. The first gear includes a first external thread. The first gear is configured to rotate about a first axis. The second gear is at least partially disposed within the longitudinal passage. The second gear includes external teeth and an internal thread. The second gear defines a gear passage. The external teeth are operatively connected to the first external thread. The second gear is configured to rotate about a second axis perpendicular to the first axis. The lead screw extends through the gear passage. The lead screw includes a second external thread.The second external thread is in operative connection with the internal thread.

[0024] In one implementation, the first curved surface and the second curved surface both define (i) a portion of an ellipsoidal surface, (ii) a portion of a conical surface, or (iii) a portion of a spherical surface.

[0025] In one implementation, the second gear is one of (i) a spiral gear or (ii) a single enveloping worm gear.

[0026] In one implementation, the second external thread is a trapezoidal thread, and the spindle screw has a 3 mm pitch, a 1.5 mm thread lead, and one of (i) an 8 mm nominal diameter and (ii) a 9 mm nominal diameter. In another implementation, the second external thread is a trapezoidal thread, and the spindle screw has a 4 mm pitch, a 2 mm thread lead, and one of (i) an 11 mm nominal diameter and (ii) a 12 mm nominal diameter.

[0027] In one implementation, the gear system is configured to operate at one of the following: (i) a comfort speed has a linear adjustment speed in the range of 17 mm / s to 22 mm / s, (ii) a high speed has a linear adjustment speed in the range of 55 mm / s to 60 mm / s, or (iii) a very high speed has a linear adjustment speed in the range of 85 mm / s to 90 mm / s.

[0028] In one implementation, one of the first portion and the second portion includes a frustoconical protrusion and an annular protrusion extending from a respective one of the first curved surface and the second curved surface. The annular protrusion is disposed about a base of the frustoconical protrusion and coaxial with the frustoconical protrusion. The other of the first portion and the second portion includes a frustoconical receptacle and an annular recess defined by a respective one of the first curved surface and the second curved surface. The annular recess is coaxial with the frustoconical receptacle. The frustoconical receptacle is configured to receive the frustoconical protrusion, and the annular recess is configured to receive the annular protrusion.

[0029] In another form, the present disclosure provides a vehicle seat adjustment mechanism including a gear box, a first gear, a second gear, and a lead screw. The first gear is received in the gear box and rotatable relative to the gear box about a first axis. The second gear is received in the gear box and rotatable relative to the gear box about a second axis perpendicular to the first axis. The first and second gears are in meshing engagement with each other. The lead screw is in meshing engagement with the second gear and extends through the second gear along the second axis.The spindle screw is selected from the group consisting of: a first spindle screw with trapezoidal thread and defined by Tr 8x3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread pitch), a second spindle screw with trapezoidal thread and defined by Tr 9x3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread pitch), a third spindle screw with trapezoidal thread and defined by Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch and 2 mm thread pitch) and a fourth spindle screw with trapezoidal thread and defined by Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch and 2 mm thread pitch).

[0030] In some implementations, the vehicle seat adjustment mechanism further includes a motor that drives the first gear, the motor having a maximum rotational speed of 5,500 revolutions per minute.

[0031] In some implementations, the gear box, the first gear, and the second gear are configured to move along the second axis at one of the following: (i) a comfort speed with a linear adjustment speed in the range of 17 mm / s to 22 mm / s, (ii) a high speed with a linear adjustment speed in the range of 55 mm / s to 60 mm / s, or (iii) a very high speed with a linear adjustment speed in the range of 85 mm / s to 90 mm / s.

[0032] In some implementations, the first gear is a cylindrical worm gear and the second gear is one of a spiral gear or a single enveloping worm gear.

[0033] In some implementations, a gear ratio of the first gear to the second gear is selected from the group consisting of: 3.333, 3.25, 3.2, 2.833, 2.8, 2.75, 2.6, 2.4, and 2.2.

[0034] In some implementations, a gear ratio of the first gear to the second gear is selected from the group consisting of: 8.5, 7.5, 6.5, 5.667, 5.333, 4.667, 4.333, 3.667, and 3.333.

[0035] The vehicle seat adjustment mechanism may be incorporated into a seat track assembly including a lower seat track and an upper seat track configured to engage the lower seat track and slide along a length of the lower seat track, wherein the gear box is configured to be mounted to the upper seat track.

[0036] In some implementations, the gear box includes: a first portion including a first body, the first body defining a first longitudinal recess and a first circumferential recess in fluid communication with the first longitudinal recess; and a second portion including a second body, the second body defining a second longitudinal recess and a second circumferential recess in fluid communication with the second longitudinal recess.

[0037] In some implementations, the first body includes a first curved surface that is concave, the second body includes a second curved surface, the second curved surface being convex and having an equal and opposite curvature compared to the first curved surface, and in an assembled configuration: the first curved surface is in contact with the second curved surface, the first longitudinal recess communicates with the second longitudinal recess to define a longitudinal passage, and the first circumferential recess communicates with the second circumferential recess to define a circumferential receptacle.

[0038] In some implementations, the first curved surface and the second curved surface both define (i) a portion of an ellipsoidal surface, (ii) a portion of a conical surface, or (iii) a portion of a spherical surface.

[0039] In some implementations, one of the first portion and the second portion includes a frustoconical protrusion extending from a respective one of the first curved surface and the second curved surface, the other of the first portion and the second portion includes a frustoconical receptacle defined by a respective one of the first curved surface and the second curved surface, and in the assembled configuration, the frustoconical receptacle receives the frustoconical protrusion.

[0040] In some implementations, one of the first portion and the second portion further includes an annular protrusion extending from the respective one of the first curved surface and the second curved surface, the annular protrusion being disposed about a base of the frustoconical protrusion and coaxial with the frustoconical protrusion, the other of the first portion and the second portion further includes an annular recess defined by a respective one of the first curved surface and the second curved surface, the annular recess being coaxial with the frustoconical receptacle, and in the assembled configuration, the annular recess receives the annular protrusion.

[0041] In some implementations, the frustoconical projection includes a first frustoconical projection and a second frustoconical projection, the frustoconical receptacle includes a first frustoconical receptacle and a second frustoconical receptacle, the annular projection includes a first annular projection and a second annular projection, and the annular recess includes a first annular recess and a second annular recess.

[0042] In some implementations, the vehicle seat adjustment mechanism includes an elastic layer disposed on at least one of the first curved surface or the second curved surface.

[0043] In some implementations, one of the first portion and the second portion includes an integrated rivet extending from a respective one of the first curved surface and the second curved surface, and the other of the first portion and the second portion includes an opening defined in a respective one of the first curved surface and the second curved surface, the opening configured to receive a portion of the integrated rivet.

[0044] In some implementations, the spindle screw is the first spindle screw and has a minimum axial strength of 19 kN.

[0045] In some implementations, the spindle screw is the second spindle screw and has a minimum axial strength of 25 kN.

[0046] In some implementations, the spindle screw is the third spindle screw and has a minimum axial strength of 37 kN.

[0047] In some implementations, the spindle screw is the fourth spindle screw and has a minimum axial strength of 45 kN.

[0048] The present disclosure also provides a vehicle seat adjustment mechanism including a gear box, a first gear, a second gear, a motor, and a lead screw. The first gear is received in the gear box and rotatable relative to the gear box about a first axis. The second gear is received in the gear box and rotatable relative to the gear box about a second axis perpendicular to the first axis. The first and second gears are in meshing engagement with each other. The motor drives the first gear and has a maximum rotational speed of 5,500 revolutions per minute. The lead screw is in meshing engagement with the second gear and extends through the second gear along the second axis.The spindle screw is selected from the group consisting of: a first spindle screw with trapezoidal thread and defined by Tr 8x3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread pitch), a second spindle screw with trapezoidal thread and defined by Tr 9x3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread pitch), a third spindle screw with trapezoidal thread and defined by Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch and 2 mm thread pitch) and a fourth spindle screw with trapezoidal thread and defined by Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch and 2 mm thread pitch).The gear box includes: a first portion including a first body, the first body defining a first longitudinal recess and a first circumferential recess in fluid communication with the first longitudinal recess; and a second portion including a second body, the second body defining a second longitudinal recess and a second circumferential recess in fluid communication with the second longitudinal recess. The first body includes a first curved surface that is concave. The second body includes a second curved surface that is convex and has an equal and opposite curvature compared to the first curved surface.In an assembled configuration, the first curved surface is in contact with the second curved surface, the first longitudinal recess communicates with the second longitudinal recess to define a longitudinal passage, and the first circumferential recess communicates with the second circumferential recess to define a circumferential receptacle.

[0049] Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are for illustrative purposes only and are not intended to limit the scope of the present disclosure. DRAWINGS

[0050] The drawings described herein are intended to illustrate selected embodiments only and not all possible implementations and are not intended to limit the scope of the present disclosure. Fig. 1 is a partial perspective view of a vehicle seat assembly having a pair of seat track assemblies each including an externally powered seat length adjustment assembly in accordance with the principles of the present disclosure; Fig. 2 is a perspective view of the externally powered seat length adjustment assembly of Fig. 1; Fig. 3 is an exploded perspective view of an adjustment subassembly of the externally powered seat length adjustment assembly of Fig. 2; Fig. 4A- Fig. 4E relate to a closed-type gear box with ellipsoidal mating surfaces according to the principles of the present disclosure; Fig. 4A is a perspective view of the gear box and a representative ellipsoid; Fig. 4B is a perspective view of the gear box; Fig. 4C is a first side view of the gear box; Fig. 4D is a second side view of the gear box; and Fig. 4E is an exploded perspective view of the gear box; Fig. 5A- Fig. 5B relate to an open-type gear box with ellipsoidal mating surfaces according to the principles of the present disclosure; Fig. 5A is a perspective view of the gear box; and Fig. 5B is an exploded perspective view of the gear box; Fig. 6A- Fig. 6D relate to an open-type gear box with tapered mating surfaces according to the principles of the present disclosure; Fig. 6A is a perspective view of the gear box and a representative cone; Fig. 6B is a first side view of the gear box; Fig. 6C is a second side view of the gear box; and Fig. 6D is an exploded perspective view of the gear box; Fig. 7A- Fig. 7E relate to an open-type gear box with spherical mating surfaces according to the principles of the present disclosure; Fig. 7A is a perspective view of the gear box and a representative ball; Fig. 7B is a perspective view of the gear box; Fig. 7C is a first side view of the gear box; Fig. 7D is a second side view of the gear box; and Fig. 7E is an exploded perspective view of the gear box; Fig. 8A- Fig. 8B refer to pre-assembly connection stop features; Fig. 8A is a perspective detail view of a recess of a pre-assembly connection stop feature of the gear box of Fig. 5B; and Fig. 8B is a perspective detail view of a protrusion of the pre-assembly connection stop feature of Fig. 5B; Fig. 9 is an exploded perspective view of a gear box with a single connecting stop feature according to the principles of the present disclosure; Fig. 10 is an exploded perspective view of a gear box free of pre-assembly connection stop features in accordance with the principles of the present disclosure; Fig. 11A- Fig. 11B relate to a gear box with an elastic layer according to the principles of the present disclosure; Fig. 11A is an exploded perspective view of the gear box; and Fig. 11B is a perspective view of the gear box; Fig. 12A- Fig. 12C refer to a gear box arrangement which separates the gear box from Fig. 5A- Fig. 5B assembled with screws in accordance with the principles of the present disclosure; Fig. 12A is a perspective view of the gear box assembly; and Fig. 12B is a partial sectional view taken along line 12B-12B of Fig. 12A; Fig. 12C is a sectional view taken along line 12C-12C of Fig. 12A; Fig. 13A- Fig. 13D refer to a gear box arrangement which separates the gear box from Fig. 5A- Fig. 5B assembled with discrete rivets in accordance with the principles of the present disclosure; Fig. 13A is an exploded perspective view of the gear box assembly with the rivets in an undeformed state; Fig. 13B is a perspective view of the gear box assembly with the rivets in the undeformed state; Fig. 13C is a sectional view of the gear box assembly taken along line 13C-13C of Fig. 13B, wherein the rivets are in the undeformed state; and Fig. 13D is a sectional view of the gear box assembly taken along line 13D-13D of Fig. 13B, wherein the rivets are in a deformed state; Fig. 14A- Fig. 14D relate to a gear box assembly including a gear box with integrated rivets according to the principles of the present disclosure; Fig. 14A is an exploded perspective view of the gear box with the rivets in an undeformed state; Fig. 14B is a perspective view of the gear box with the rivets in the undeformed state; Fig. 14C is a sectional view taken along line 14C-14C of Fig. 14B, wherein the rivets are in an undeformed state; and Fig. 14D is a sectional view taken along line 14D-14D of Fig. 14B, wherein the rivets are in a deformed state; Fig. 15A- Fig. 15D relate to an externally driven, enhanced strength, enveloping gear, comfort speed length adjustment assembly according to the principles of the present disclosure; Fig. 15A is a partial perspective view of the adjustment assembly; Fig. 15B is a partially cutaway perspective view of the adjustment assembly; Fig. 15C is a sectional view of the adjustment assembly taken along line 15C-15C of Fig. 15A; and Fig. 15D is a sectional view of the adjustment assembly taken along line 15D-15D of Fig. 15A; Fig. 16A- Fig. 16E relate to an externally driven, enhanced strength, spiral gear, comfort speed length adjustment assembly according to the principles of the present disclosure; Fig. 16A is a partially exploded perspective view of the adjustment assembly; Fig. 16B is a partial perspective view of the adjustment assembly; Fig. 16C is a partially cutaway perspective view of the adjustment assembly; Fig. Figure 16D is a sectional view of the adjustment assembly taken along line 16D-16D of Fig. 16B; and Fig. 16E is a sectional view of the adjustment assembly taken along line 16E-16E of Fig. 16B; Fig. 17A- Fig. 17D relate to a normal strength, high speed, enveloping gear, externally driven length adjustment assembly according to the principles of the present disclosure; Fig. 17A is a partial perspective view of the adjustment assembly; Fig. 17B is a partially cutaway perspective view of the adjustment assembly; Fig. Figure 17C is a sectional view of the adjustment assembly taken along line 17C-17C of Fig. 17A; and Fig. 17D is a sectional view of the adjustment assembly taken along line 17D-17D of Fig. 17A; Fig. 18A- Fig. 18D relate to a normal strength, high speed, spiral gear, externally driven length adjustment assembly according to the principles of the present disclosure; Fig. 18A is a partial perspective view of the adjustment assembly; Fig. 18B is a partially cutaway perspective view of the adjustment assembly; Fig. 18C is a sectional view taken along line 18C-18C of Fig. 18A; and Fig. 18D is a sectional view taken along line 18D-18D of Fig. 18A; Fig. 19A- Fig. 19D relate to a normal strength, very high speed, spiral gear, externally driven length adjustment assembly according to the principles of the present disclosure; Fig. 19A is a partial perspective view of the adjustment assembly; Fig. 19B is a partially cutaway perspective view of the adjustment assembly; Fig. 19C is a sectional view taken along line 19C-19C of Fig. 19A; and Fig. 19D is a sectional view taken along line 19D-19D of Fig. 19A; Fig. 20A- Fig. 20D relate to a high strength, spiral gear, very high speed, externally driven length adjustment assembly according to the principles of the present disclosure; Fig. 20A is a partial perspective view of the adjustment assembly; Fig. 20B is a partially cutaway perspective view of the adjustment assembly; Fig. 20C is a sectional view taken along line 20C-20C of Fig. 20A; and Fig. 20D is a sectional view taken along line 20D-20D of Fig. 20A; Fig. 21A- Fig. 21D relate to a very high strength, spiral gear, very high speed, externally driven length adjustment assembly according to the principles of the present disclosure; Fig. 21A is a partial perspective view of the adjustment assembly; Fig. 21B is a partially cutaway perspective view of the adjustment assembly; Fig. 21C is a sectional view taken along line 21C-21C of Fig. 21A; and Fig. 21D is a sectional view taken along line 21D-21D of Fig. 21A; Fig. 22 is an exploded view of an externally driven, open-architecture seat length adjustment assembly constructed in accordance with the principles of the present disclosure, showing worm-to-worm gears for achieving nine different gear ratios; and Fig. Figure 23 is an exploded view of an externally driven, open architecture seat length adjustment assembly constructed in accordance with the principles of the present disclosure wherein helical-type worm and spiral gear drives may be used to achieve nine different gear ratios.

[0051] Corresponding reference numerals indicate corresponding parts in the several views of the drawings. DETAILED DESCRIPTION

[0052] Examples of vehicle seat adjustment mechanisms will now be described in more detail with reference to the accompanying drawings.

[0053] Example embodiments are provided so that this disclosure will be thorough and will fully convey the scope to those skilled in the art. Numerous specific details are set forth, such as examples of specific components, devices, and methods, in order to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that none should be construed as limiting the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.

[0054] The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "the" may also include the plural forms, unless the context clearly indicates otherwise. The terms "comprises," "having," "including," and "having" are inclusive and therefore indicate the presence of specified features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.The method steps, processes, and operations described herein should not be construed as necessarily requiring their performance in the particular order explained or illustrated unless specifically identified as such. It is also understood that additional or alternative steps may be used.

[0055] When an element or layer is described as being "on / upon," "engaging with," "connected to," or "coupled to" another element or layer, it may be directly on / upon, engaged with, connected to, or coupled to the other element or layer, or there may be intervening elements or layers. Conversely, when an element is described as being "directly on / upon," "directly engaging with," "directly connected to," or "directly coupled to" another element or layer, there may be no intervening elements or layers. Other words used to describe the relationship between elements should be interpreted similarly (e.g., "between" versus "directly between," "adjacent" versus "directly adjacent," etc.).As used herein, the term “and / or” includes all combinations of one or more of the related listed items.

[0056] Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers, and / or sections, those elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may only be used to distinguish one element, component, region, layer, or section from another region, layer, or section. Terms such as "first," "second," and other numerical terms, when used herein, do not imply a sequence or order unless clearly indicated by context.Thus, a first element, component, region, layer, or portion discussed below could be referred to as a second element, component, region, layer, or portion without departing from the teachings of the exemplary embodiments.

[0057] Spatially relative terms, such as "inner," "outer," "beneath," "under," "lower," "above," "upper," and the like, may be used herein for ease of description to describe the relationship of one element or feature to one or more other elements or features, as illustrated in the figures. Spatially relative terms may be intended to encompass various orientations of the device in use or operation in addition to the orientation illustrated in the figures. For example, if the device in the figures is turned over, elements described as being "below" or "next to" other elements or features would then be oriented "above" the other elements or features. Thus, the example term "below" can encompass both an above and below orientation.The device may be oriented differently (rotated 90 degrees or in other orientations) and the spatially relative descriptors used here may be interpreted accordingly.

[0058] With reference to Fig. 1, a seat assembly 10 is provided. The seat assembly 10 may include a backrest 12, a seat bottom 14, and one or more seat track assemblies 16. In some implementations, the seat assembly 10 is adjustably mounted to a vehicle (not shown), such as an automobile. For example, a recline mechanism (not shown) may pivotally move the backrest 12 relative to the seat bottom 14, and the seat track assemblies 16 may translate the seat bottom 14 to a particular position relative to a vehicle floor pan (not shown). Accordingly, a user may selectively change the orientation of the backrest 12 relative to the seat bottom 14 using the recline mechanism (not shown) and the position of the seat assembly 10 relative to the vehicle floor pan using the pair of seat track assemblies 16.

[0059] Each seat track assembly 16 may include a lower track 20, an upper track 22, and an adjustment assembly 24. The adjustment assembly 24 may be fixedly attached to a portion of the upper track 22 by one or more mechanical fasteners 26 (e.g., bolts, screws, rivets, etc.). In certain implementations, the upper track 22 defines one or more cutouts (not shown) to accommodate the adjustment assembly 24.

[0060] The lower rail 20 may be fixedly attached to a portion of the vehicle using one or more mechanical fasteners 28 (e.g., bolts, screws, rivets, etc.) or any other suitable fastening technique and may define an axis A1. The lower rail 20 may define a U-shaped profile extending in a direction substantially parallel to the axis A1 such that walls of the lower rail 20 cooperate to define a central lower channel 30.

[0061] The upper rail 22 may be fixedly attached to a portion of the seat base 14 using one or more mechanical fasteners 32 (e.g., bolts, screws, rivets, etc.) or any other suitable fastening technique. The upper rail 22 may define a U-shaped profile extending in a direction substantially parallel to the axis A1 such that walls of the upper rail 22 cooperate to define a central upper channel 34.

[0062] In an assembled configuration, as shown, the lower rail 20 may support the upper rail 22 for translation along the axis A1 such that the upper rail 22 translates relative to the vehicle. For example, the lower rail 20 may support the upper rail 22 for translation along the axis A1 by sliding. The upper rail 22 may translate relative to the lower rail 20 to enable selective movement of the backrest 12 and the seat bottom 14 relative to the vehicle. Movement of the upper rail 22 relative to the lower rail 20 may be facilitated by a carriage assembly 50 including two pairs of ball cage assemblies 52 that may: (i) be attached to the upper rail 22 and / or the adjustment assembly 24, and (ii) be at least partially received within the central lower channel 30 of the lower rail 20.

[0063] With reference to Fig. 2, the adjustment assembly 24 may include a drive assembly 54, a spindle screw or lead screw 56, and an adjustment subassembly 58. In an assembled configuration, a portion of the adjustment assembly 24 may be secured relative to the vehicle and another portion of the adjustment assembly 24 may be secured relative to the upper track 22 to facilitate movement of the backrest 12 and seat bottom 14 relative to the vehicle. For example, the spindle screw 56 may be secured to the lower track 20 and / or the vehicle floor, while the adjustment subassembly 58 may be secured to the upper track 22. Accordingly, movement of the adjustment subassembly 58 relative to the spindle screw 56 causes the forward and rearward movement of the upper track 22 and seat bottom 14 relative to the lower track 20 and ultimately relative to the vehicle floor.

[0064] The drive assembly 54 may include a bidirectional electric motor and two flexible drive shafts that transmit the rotational speed and torque from the electric motor to the adjustment subassembly 58 to enable movement of the adjustment subassembly 58 along the length of the spindle screw 56 and thus forward and rearward movement of the seat assembly 10 ( Fig. 1) relative to the vehicle floor.

[0065] The spindle screw 56 may include a front end 62 and a rear end 64. In some implementations, the spindle screw 56 may define a substantially cylindrical rod that defines an axis A2 extending from the front end 62 to the rear end 64 and has an external thread 66 extending along and around the axis A2 from the front end 62 to the rear end 64. In an assembled configuration, the spindle screw 56 may be disposed in one or both of the central lower channel 30 of the lower rail 20 and the central upper channel 34 of the upper rail 22 such that the axis A2 is substantially parallel to the axis A1 ( Fig. 1). The front end 62 and the rear end 64 may be secured relative to the lower rail 20 and / or the vehicle floor by bolts rigidly mounted to the lower rail 20. For example, the front end 62 may be supported by a front spindle mount 68 secured to the lower rail 20 and / or the vehicle floor, and the rear end 64 may be supported by a rear spindle mount 70 also secured to the lower rail 20 and / or the vehicle floor.

[0066] With reference to at least Fig. 3, the adjustment subassembly 58 may include a support frame 74, a housing assembly 76, a pair of bearing bushes 78, a first gear or cylindrical worm 80 having a helical external thread 82 in engagement with external teeth 84 of a second gear or enveloping worm 86, a spindle nut integrally formed with the second gear 86 and having an internal thread 90, and the spindle screw 56 having the external thread 66 ( Fig. 2), which engages the internal thread 90 of the spindle nut. The first and second gears 80, 86 may collectively be referred to as a gear system or gear arrangement.

[0067] The support frame 74 may define a U-shape. The support frame 74 may include a base 100, a pair of walls 102 extending substantially perpendicular to the base 100 at opposite ends of the base 100, and a pair of flanges 104 extending substantially perpendicular to the pair of walls 102 and substantially parallel to the base 100, respectively. The base 100, the walls 102, and the flanges 104 may be integrally formed. The base 100 and the walls 102 may cooperate to define an interior region 106. The pair of walls 102 may define a respective pair of wall openings 108. The pair of flanges 104 may define a respective pair of flange openings 110.

[0068] The housing assembly 76 may include a gear box 114, a first cover shell 116, and a second cover shell 118 (also referred to as the "pair of cover shells 116, 118"). The first and second cover shells 116, 118 may be geometrically mirrored. The first and second cover shells 116, 118 may define respective first and second shell openings 120, 122. The first and second cover shells 116, 118 may define respective first and second shell interior regions 124, 126.

[0069] The first and second cover shells 116, 118 may be formed from a resilient material with noise and vibration dampening properties. In some implementations, the first and second cover shells 116, 118 may be formed from a polymer, such as rubber. The use of rubber shells 116, 118 pressed against the walls 102 of the support frame 74 may increase the damping capability of the adjustment subassembly 58 in the process of transmitting vibration to the seat structure.

[0070] The gear case 114 may be formed from aluminum-zinc alloy die-cast material. The gear case 114 may include a first part or section 130 and a second part or section 132. Each of the first and second sections 130, 132 may define a longitudinal recess 134, a circumferential recess 136, and an opening 138. Each of the first and second sections 130, 132 further includes a curved mating surface 140. In an assembled condition, the curved mating surfaces 140 of the first and second sections 130, 132 are in contact with each other, the longitudinal recesses 134 cooperate to define a longitudinal passage, and the circumferential recesses 136 cooperate to define a circumferential receptacle. The gear box 114 may be secured in the assembled configuration by a plurality of fasteners 142 (e.g., screws, bolts, rivets, etc.).Various implementations of gear boxes are described in more detail below.

[0071] The cylindrical worm 80 may define a rotational axis A3 extending from a first end 150 to a second end 152. The helical external thread 82 may be disposed about the rotational axis A3 between the first and second ends 150, 152. In various implementations, the cylindrical worm 80 may be manufactured from a plastic material such as PEEK 450G through an injection molding process. The cylindrical worm 80 may be rotatably supported by the housing assembly 76. For example, the first end 150 of the cylindrical worm 80 may be rotatably disposed within the opening 138 of the first portion 130 of the gear case 114, and the second end 152 of the cylindrical worm 80 may be rotatably disposed within the opening 138 of the second portion 132 of the gear case 114.

[0072] The enveloping worm 86 may define a rotational axis A4 extending from a first end 154 to a second end 156. The internal thread 90 and the external teeth 84 may be arranged about the rotational axis A4. The bearing bushings 78 may include respective through holes 160 that receive outer bearing surfaces 162 of the enveloping worm 86. In the assembled configuration, the enveloping worm 86 and the bearing bushings 78 may be disposed at least partially within the longitudinal passage (formed by longitudinal recesses 134) of the gear case 114. The enveloping worm 86 may be disposed between the bearing bushings 78 and rotatable with respect to the bearing bushings 78. The bearing bushings 78 may be rotatably fixed with respect to the gear case 114 by engagement of radially extending tabs 164 of the bearing bushings 78 with the gear case 114.

[0073] In the assembled configuration, the gear box 114 is disposed between the cover shells 116, 118 and at least partially within the shell interior regions 124, 126. The housing assembly 76, which includes the gear box 114 and the cover shells 116, 118, is at least partially disposed within the interior region 106 of the support frame 74. The spindle screw 56 ( Fig. 2) extends through a gear passage 166 of the enveloping worm 86, the through holes 160 of the bearing bushes 78, the longitudinal passage (formed by the longitudinal recesses 134), the first and second shell openings 120, 122 and the wall openings 108. The internal thread 90 of the enveloping worm 86 is connected to the external thread 66 ( Fig. 2) the spindle screw 56 ( Fig. 2) and the external teeth 84 of the enveloping worm 86 are meshingly engaged with the spiral external thread 82 of the cylindrical worm 80.

[0074] The rotational axis A4 of the enveloping worm 86 may be substantially parallel to and aligned with the axis A2 of the spindle screw 56. The rotational axis A3 of the cylindrical worm 80 may be substantially perpendicular to the axes A2 and A4. In the assembled configuration, the adjustment subassembly 58 may be disposed within the central lower channel 30 of the lower rail 20 and / or the central upper channel 34 of the upper rail 22. The axes A2, A4 may be substantially parallel to and aligned with the axis A1. Gear boxes

[0075] A gear box according to the principles of the present disclosure may include one or more features to facilitate alignment of the two sections of the gear box, distribute stresses, increase ease of assembly, improve assembly accuracy, accommodate manufacturing tolerances, reduce or eliminate vibration and / or noise during use, and / or provide modularity to accommodate a variety of gear assembly configurations, as described in more detail below. In particular, a gear box according to the principles of the present disclosure may include curved mating surfaces, one or more pre-assembly connection stop features, and / or a resilient layer, each of which is described in more detail below.

[0076] Additionally, each of the gear boxes may be an open-type gear box or a closed-type gear box. A closed-type gear box includes a wall, such as a top wall, that at least partially encloses a worm gear. Closed-type gear boxes may be used to reduce or eliminate contamination of gear systems within the gear box and / or to eliminate noise during use of the gear system. In some implementations, a closed-type gear box may be used to enable noise reduction in a high-speed gear system operating at a higher meshing frequency compared to lower rotational speed gear systems. An example of a closed-type gear box is shown in Fig. 4A- Fig. 4E and Fig. 20A- Fig. 21D. Open-type gear boxes can be used in applications with little or no expected contamination and / or low expected noise. In some implementations, an open-type gear box can be used with a comfort-speed or high-speed transmission system that is not expected to emit significant noise during use. Examples of open-type gear boxes are shown in Fig. 5A- Fig. 7E, Fig. 9- Fig. 11B and Fig. 15A- Fig. 19D shown.

[0077] The first and second sections of the gear box can be manufactured using a die-casting process. The gear box can comprise cast metal, such as an aluminum-zinc alloy. The gear boxes can be assembled using various types of discrete or one-piece fasteners. Curved mating surfaces

[0078] A two-piece gear box according to the principles of the present disclosure may include curved mating surfaces. The curved mating surfaces may be defined by a portion of a three-dimensional curve, such as an ellipsoid, a cone, or a sphere. The two-piece gear box includes a first portion with a first curved mating surface and a second portion with a second curved mating surface. One of the mating surfaces is convex, while the other mating surface is concave. The mating surfaces may define substantially the same shape with equal and opposite curvature.

[0079] The mating surfaces can be self-centering in at least two orthogonal directions. In certain implementations, the mating surfaces are self-centering in three orthogonal directions (e.g., spherical mating surfaces). Accordingly, the curved mating surfaces can facilitate efficient assembly and pre-assembly with improved accuracy. Furthermore, gear boxes with the self-centering mating surfaces can be free of certain other alignment features. In addition to facilitating alignment, the curved mating surfaces also increase surface contact between the two gear box sections, thereby improving shear stress distribution in the gear box assembly during normal and / or shock loading conditions.

[0080] With reference to Fig. 4A-4E, a gear box 400 is provided in accordance with the principles of the present disclosure. The gear box 400 includes a first part or portion 402 and a second part or portion 404. A boundary or junction 406 between the first and second portions 402, 404 defines a portion of an ellipsoid 408. The ellipsoid 408 may define a first, or vertical, radius and a second, or horizontal, radius. In certain implementations, the first radius is in a range of 190 mm to 200 mm, and the second radius is in a range of 240 mm to 250 mm.

[0081] The first portion 402 includes a first body 410. The first body 410 includes a first outer surface 412 and a first mating surface or curved surface 414. The first mating surface 414 is concave such that it curves inwardly 415 away from the second portion 404. The second portion 404 includes a second body 416. The second body 416 includes a second outer surface 418 and a second mating surface or curved surface 420. The second mating surface 420 is convex such that it curves outwardly 421 toward the first portion 402. Curvatures of the first and second mating surfaces 414, 420 are substantially equal and opposite. In particular, the first mating surface 414 is defined by a portion of a radially outer side 422 of the ellipsoid 408 and the second mating surface 420 is defined by a portion of a radially inner side 424 of the ellipsoid 408.

[0082] During pre-assembly of the gear box 400, the mating surfaces 414, 420 may be configured to have a self-centering effect on the first and second sections 402, 404 to facilitate alignment of the first and second sections 402, 404. Prior to alignment during pre-assembly, the mating surfaces 414, 420 may be in less than complete contact (i.e., gaps may exist between the first and second mating surfaces 414, 420). One or both of the sections 402, 404 may be moved along a first orthogonal direction 426 and / or a second orthogonal direction 428 with respect to the other of the sections 402, 404 until the sections 402, 404 slide into alignment. This may be referred to as bidirectional self-centering. When the portions 402, 404 are aligned, the first and second mating surfaces 414, 420 may be in substantially continuous contact at the boundary 406.

[0083] The first body 410 of the first portion 402 defines a first longitudinal recess 440 and a first circumferential recess 442. The first longitudinal recess 440 and the first circumferential recess 442 are in fluid communication. The first body 410 includes a first wall 444. The first wall 444 at least partially defines the first circumferential recess 442. The first wall 444 may be partially cylindrical.

[0084] The second body 416 of the second portion 404 defines a second longitudinal recess 446 and a second circumferential recess 448. The second longitudinal recess 446 and the second circumferential recess 448 are in fluid communication. The second body 416 includes a second wall 450. The second wall 450 at least partially defines the second circumferential recess 448. The second wall 450 may be partially cylindrical.

[0085] The first and second longitudinal recesses 440, 446 cooperate to form a longitudinal passage 452 ( Fig. 4B-4C). The longitudinal passage 452 may extend continuously between the first and second sides of the gear box 400. When the gear box 400 is mounted in a vehicle seat adjustment assembly, the longitudinal passage 452 may be connected to axes of a lower rail, a spindle screw, and a second gear (e.g., the lower rail 20, the spindle screw 56, and the second gear 86 of Fig. 1-3). The longitudinal passage 452 may be configured to receive a second gear, a portion of a spindle screw, and a bearing (e.g., the second gear 86, the spindle screw 56, and the bearing bushings 78 of Fig. 1-3).

[0086] The first and second circumferential recesses 442, 448 cooperate to form a circumferential receptacle 454 ( Fig. 4C). The peripheral receptacle 454 is partially enclosed by the first and second walls 444, 450. Accordingly, the gear box 400 may be described as a closed-type gear box. The peripheral receptacle 454 may be configured to receive a first gear (e.g., the first gear 80 of Fig. 1-3). The first and second bodies 410, 416 may define respective first and second openings 460, 462. The first and second openings 460, 462 may be configured to receive first and second bearing surfaces of a first gear (e.g., the first gear 80 of Fig. 1-3).

[0087] The first body 410 of the first section 402 may define a plurality of third openings 464. The second body 416 of the second section 404 may define a plurality of fourth openings 466. When the gear box 400 is assembled, the third openings 464 are each axially aligned with the fourth openings 466. The openings 444, 466 may be configured to receive a plurality of fasteners, as described in more detail below (see the discussion that Fig. 12A-14D) to hold the gear box 400 in the assembled configuration.

[0088] The gear box 400 may further include a pair of pins 470 and a pair of receptacles 472. In the illustrated implementation, the pins 470 protrude from the second mating surface 420 of the second portion 404, and the receptacles 472 are defined in the first body 410 of the first portion 402. However, in other implementations, a first portion may include the pins, while a second portion includes the receptacles. In some implementations, the first and second portions may each include a pin and a receptacle.

[0089] The receptacles 472 may be blind holes. The pins 470 may be frustoconical, having a largest diameter adjacent the second body 416. The receptacles 472 may be frustoconical, having a largest diameter at the first mating surface 414. The receptacles 472 may be configured to receive respective pins 470 during pre-assembly of the gear box 400. The pins 470 may be disposed in the receptacles 472 when the gear box 400 is in the assembled configuration.

[0090] In various implementations, the gear box 400 may further include one or more pre-assembly connection stop features. For example, the gear box 400 may include annular projections 480 to be received in annular recesses 482. The annular projections 480 may be coaxial with the pins 470, and the annular recesses 482 may be coaxial with the receptacles 472. A gear box according to the principles of the present disclosure may be free of pre-assembly connection stop features, include a single stop feature, include two stop features (e.g., the pair of annular projections 480 and the pair of annular recesses 482) as shown, or include more than two stop features. Pre-assembly connection stop features are described below in the discussion that Fig. 8A-10, described in more detail.

[0091] With reference to Fig. 5A-5B, another gear box 400a is illustrated. The structure and function of gear box 400a may be substantially similar to that of gear box 400, except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals including letter extensions (i.e., "a") are used to identify those features that have been modified.

[0092] The gear box 400a includes a first part or section 402a and a second part or section 404a. A boundary or connection 406a between the first and second sections 402a, 404a defines a section of an ellipsoid 408.

[0093] The first portion 402a includes a first body 410a. The first body 410a includes a first outer surface 412a and a first mating surface or curved surface 414a. The first mating surface 414a is concave. The second portion 404a includes a second body 416a. The second body 416a includes a second outer surface 418a and a second mating surface or curved surface 420a. The second mating surface 420a is convex.

[0094] The first body 410a of the first section 402a defines a first longitudinal recess 440 and a first circumferential recess 442a. The first longitudinal recess 440 and the first circumferential recess 442a are in fluid communication. The second body 416a of the second section 404a defines a second longitudinal recess 446 and a second circumferential recess 448a. The second longitudinal recess 446 and the second circumferential recess 448a are in fluid communication.

[0095] The first and second longitudinal recesses 440, 446 cooperate to form a longitudinal passage 452 ( Fig. 5A). The first and second circumferential recesses 442a, 448a cooperate to define a circumferential receptacle 454a ( Fig. 5A). The circumferential receptacle 454a is open to an outer region 500 of the gear box 400a at a circumferential opening 502 defined by the first and second bodies 410a, 416a when the gear box 400a is in the assembled configuration. Accordingly, the gear box 400a may be described as an open-type gear box. The circumferential receptacle 454a may be configured to at least partially receive a first gear (e.g., the first gear 80 of Fig. 1-3), such as in first and second openings 460, 462 that support first and second bearing surfaces of the first gear. A portion of the first gear may protrude from the gear case 400a through the circumferential opening 502.

[0096] The gear box 400a may further include third and fourth openings 464, 466 for receiving fasteners, pins 470 and receptacles 472, and annular projections and recesses 480, 482, as shown above and in the discussion which Fig. 4A-4E accompanied, described.

[0097] With reference to Fig. 6A-6D, another gear box 400b is illustrated. The structure and function of gear box 400b may be substantially similar to that of gear box 400a, except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals including letter extensions (i.e., "b") are used to identify those features that have been modified.

[0098] The gear box 400b includes a first part or section 402b and a second part or section 404b. A boundary or junction 406b between the first and second sections 402b, 404b defines a portion of a cone 600. In certain implementations, the cone 600 may define an opening angle in the range of 165° to 172°.

[0099] The first portion 402b includes a first body 410b. The first body 410b includes a first outer surface 412a and a first mating surface or curved surface 414b. The first mating surface 414b is concave such that it curves inwardly 415 away from the second portion 404b. The second portion 404b includes a second body 416b. The second body 416b includes a second outer surface 418a and a second mating surface or curved surface 420b. The second mating surface 420b is convex such that it curves outwardly 421 toward the first portion 402b. Curvatures of the first and second mating surfaces 414b, 420b are substantially equal and opposite.

[0100] During pre-assembly of the gear box, the mating surfaces 414b, 420b may be configured to have a self-centering effect on the first and second sections 402b, 404b to facilitate alignment of the first and second sections 402b, 404b. Prior to alignment during pre-assembly, the mating surfaces 414b, 420b may be in less than complete contact (i.e., there may be gaps between the first and second mating surfaces 414b, 420b). One or both of the sections 402b, 404b may be moved along a first orthogonal direction 426 and / or a second orthogonal direction 430 with respect to the other of the sections 402b, 404b until the sections 402b, 404b slide into alignment. This may be referred to as bidirectional self-centering. When the portions 402b, 404b are aligned, the first and second mating surfaces 414b, 420b may be in substantially continuous contact at the boundary 406b.

[0101] The first body 410b of the first section 402b defines a first longitudinal recess 440 and a first circumferential recess 442a. The first longitudinal recess 440 and the first circumferential recess 442a are in fluid communication. The second body 416b of the second section 404b defines a second longitudinal recess 446 and a second circumferential recess 448a. The second longitudinal recess 446 and the second circumferential recess 448a are in fluid communication. The first and second longitudinal recesses 440, 446 cooperate to define a longitudinal passage 452 ( Fig. 6A-6B). The first and second circumferential recesses 442a, 448a cooperate to define a circumferential receptacle 454a ( Fig. 6A). While the gear box 400a is shown as an open-type gear box, in other implementations it may have walls similar or identical to the walls 444, 450 of the gear box 400 ( Fig. 4A- Fig. 4E) and be a closed type gear box.

[0102] The gear box 400b may further include third and fourth openings 464, 466 for receiving fasteners, pins 470 and receptacles 472, and annular projections and recesses 480, 482, as shown above and in the discussion which Fig. 4A-4E accompanied, described.

[0103] With reference to Fig. 7A-7E, another gear box 400c is illustrated. The structure and function of gear box 400c may be substantially similar to that of gear box 400a, except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals including letter extensions (i.e., "c") are used to identify those features that have been modified.

[0104] The gear box 400c includes a first part or section 402c and a second part or section 404c. A boundary or connection 406c between the first and second sections 402c, 404c defines a portion of a sphere 700. In certain implementations, the sphere 700 may define a radius in a range of 190 mm to 200 mm.

[0105] The first portion 402c includes a first body 410c. The first body 410c includes a first outer surface 412a and a first mating surface or curved surface 414c. The first mating surface 414c is concave such that it curves inwardly 415 away from the second portion 404c. The second portion 404c includes a second body 416c. The second body 416c includes a second outer surface 418a and a second mating surface or curved surface 420c. The second mating surface 420c is convex such that it curves outwardly 421 toward the first portion 402c. Curvatures of the first and second mating surfaces 414c, 420c are substantially equal and opposite.

[0106] During pre-assembly of the gear box, the mating surfaces 414c, 420c may be configured to have a self-centering effect on the first and second sections 402c, 404c to facilitate alignment of the first and second sections 402c, 404c. Prior to alignment during pre-assembly, the mating surfaces 414c, 420c may be in less than complete contact (i.e., there may be gaps between the first and second mating surfaces 414c, 420c). One or both of the sections 402c, 404c may be moved along a first orthogonal direction 426, a second orthogonal direction 430, and / or a third orthogonal direction 702 with respect to the other of the sections 402c, 404c until the sections 402c, 404c slide into alignment. This may be referred to as three-directional self-centering.When the portions 402c, 404c are aligned, the first and second mating surfaces 414c, 420c may be in substantially continuous contact at the boundary 406c.

[0107] The first body 410c of the first section 402c defines a first longitudinal recess 440 and a first circumferential recess 442a. The first longitudinal recess 440 and the first circumferential recess 442a are in fluid communication. The second body 416c of the second section 404c defines a second longitudinal recess 446 and a second circumferential recess 448a. The second longitudinal recess 446 and the second circumferential recess 448a are in fluid communication. The first and second longitudinal recesses 440, 446 cooperate to define a longitudinal passage 452 ( Fig. 7B-7C). The first and second circumferential recesses 442a, 448a cooperate to define a circumferential receptacle 454a ( Fig. 7B). While the gear box 400c is shown as an open-type gear box, in other implementations the gear box 400c may have walls similar or identical to the walls 444, 446 of the gear box 400 ( Fig. 4A- Fig. 4E) and be a closed type gear box.

[0108] The gear box 400c may further include third and fourth openings 464, 466 for receiving fasteners, pins 470 and receptacles 472, and annular projections and recesses 480, 482, as shown above and in the discussion which Fig. 4A-4E accompanied, described. Pre-assembly connection stop features

[0109] Gear boxes according to the principles of the present disclosure may include one or more features to facilitate pre-assembly and provide flexibility to accommodate manufacturing tolerances. Gear boxes may include a single pre-assembly connection stop feature, a double pre-assembly connection stop feature, or more than two pre-assembly connection stop features. In various implementations, a gear box may be free of pre-assembly connection stop features.

[0110] With reference to Fig. 8A is a portion of the second body 416a of the gear box 400a of Fig. 5A. The section includes the pin 470 and the annular projection 480. In various implementations, the pin 470 and the annular projection 480 may be formed integrally with the second body 420a.

[0111] The pin 470 protrudes from the second mating surface 420a. The pin 470 may have a frustoconical shape, such that it has a larger diameter at a proximal end or base closer to the second mating surface 420a and a smaller diameter at a distal end 800 farther from the second mating surface 420a. The pin 470 includes a first mating surface 802 that is frustoconical in shape.

[0112] The annular projection 480 may have a larger radius than the pin 470 and extend circumferentially around the base of the pin 470. The annular projection may extend axially from the second mating surface 420a toward the distal end 800 of the pin 470. However, the annular projection 480 may extend axially only along a portion of a length of the pin 470. The annular projection 480 includes a second mating surface 804.

[0113] With reference to Fig. 8B, the first body 410a includes the receptacle 472 and the annular recess 482. The receptacle 472 may be defined by the first mating surface 414a. The receptacle 472 may have a frustoconical shape such that it has a larger diameter at a proximal end 806 at the first mating surface 414a and a smaller diameter at a distal end 808 offset from the first mating surface 414a. The receptacle 472 includes a third mating surface 810 that is frustoconical in shape.

[0114] The annular recess 482 may have a larger radius than the receptacle 472 and may extend circumferentially around a portion of the receptacle. The annular recess may extend axially from the first mating surface 414a toward the distal end 808 of the receptacle 472. However, the annular recess 482 may extend axially only along a portion of a length of the receptacle 472. The annular recess 482 may include a fourth mating surface 812.

[0115] If the gear box 400a ( Fig. 5A) is in an assembled or pre-assembled configuration, the pin 470 is received in the receptacle 472. The first mating surface 802 of the pin 470 can engage the third mating surface 810 of the receptacle 472. The annular projection 480 is received in the annular recess 482. The second mating surface 814 of the annular projection 480 can engage the fourth mating surface 812 of the annular recess 482. Collectively, the annular projection 480 and the annular recess 482 may be referred to as a pre-assembly mating stop feature.

[0116] With further reference to Fig. 5A, the gear box 400a may include two pre-assembly connection stop features, such as the two pairs of annular projections and recesses 480, 482. That is, the gear box 400a may have dual connection stop features. The first portion 402a may include the receptacles 472 and the annular recesses 482, and the second portion 404a may include the pins 470 and the annular projections 480, as shown. In various other implementations, a first portion may include pins and projections, while a second portion includes receptacles and recesses. In various other implementations, both the first and second portions may include pins, annular projections, receptacles, and annular recesses.

[0117] With reference to Fig. 9, another gear box 400d is illustrated. The structure and function of gear box 400d may be substantially similar to that of gear box 400a, except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals including letter extensions (i.e., "d") are used to identify those features that have been modified.

[0118] The gear box 400d includes a first part or section 402d and a second part or section 404d. A boundary or connection (see, e.g., boundary 406a of Fig. 5A) between the first and second portions 402d, 404d defines a three-dimensional curve, such as a portion of an ellipsoid, a cone, or a sphere.

[0119] The first portion 402d includes a first body 410d. The first body 410d includes a first outer surface 412a and a first mating surface or curved surface 414d. The second portion 404d includes a second body 416d. The second body 416d includes a second outer surface 418a and a second mating surface or curved surface 420d. One of the first and second mating surfaces 414d, 420d is concave and the other of the first and second mating surfaces 414d, 420d is convex.

[0120] The first body 410d of the first section 402d defines a first longitudinal recess 440 and a first circumferential recess 442a. The first longitudinal recess 440 and the first circumferential recess 442a are in fluid communication. The second body 416d of the second section 404d defines a second longitudinal recess 446 and a second circumferential recess 448a. The second longitudinal recess 446 and the second circumferential recess 448a are in fluid communication.

[0121] The first and second longitudinal recesses 440, 446 cooperate to define a longitudinal passage (see, for example, longitudinal passage 452 of Fig. 5A). The first and second circumferential recesses 442a, 448a cooperate to define a circumferential receptacle (see, e.g., circumferential receptacle 454a of Fig. 5A). While the gear box 400d is shown as an open-type gear box, the gear box 400d may further include walls similar to the walls 444, 446 of the gear box 400 of Fig. 4A- Fig. 4E and be a closed-type gear box. The gear box 400d may further include third and fourth openings 464, 466 for receiving fasteners.

[0122] The second portion 404d may include a pin 470 and a pin 470d. An annular projection 480 may extend around a portion of the pin 470, as described above in the discussion Fig. 8A-8B. The pin 470d may extend from the second mating surface 420d between a proximal end or base 900 and a distal end 902. The pin 470d may include a first mating surface 904 extending between the proximal end 900 and the distal end 902.

[0123] The first portion 402d may include a receptacle 472 and a receptacle 472d. An annular recess 482 may extend around a portion of the receptacle 472, as described above in the discussion Fig. 8A-8B. The receptacle 472d may extend into the first mating surface 414d from a proximal end 906 to a distal end (not shown). The receptacle 472d may include a second mating surface 910 extending between the proximal end 906 and the distal end.

[0124] When the gear box 400d is in an assembled or pre-assembled configuration, the receptacle 472d receives the pin 470d. The first connection surface 904 can engage the second connection surface 910. The gear box 400d includes a single pre-assembly connection stop feature (e.g., the annular projection and recess 480, 482). Accordingly, the gear box 400d can be asymmetric about a plane extending through a central axis 912 and between a top surface 914 and a bottom surface 916 of the gear box 400d. Although the annular projection and recess 480, 482 are shown on a first side 918 of the plane, in various other implementations, the annular projection and recess 480, 482 can alternatively be located on a second side 920 of the plane.

[0125] With reference to Fig. 10, another gear box 400e is illustrated. The structure and function of gear box 400e may be substantially similar to that of gear box 400d, except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals including letter extensions (i.e., "e") are used to identify those features that have been modified.

[0126] The gear box 400e includes a first part or section 402e and a second part or section 404e. A boundary or connection (see, e.g., boundary 406a of Fig. 5A) between the first and second portions 402e, 404e defines a three-dimensional curve, such as a portion of an ellipsoid, a cone, or a sphere.

[0127] The first portion 402d includes a first body 410e. The first body 410e includes a first outer surface 412a and a first mating surface or curved surface 414e. The second portion 404e includes a second body 416e. The second body 416e includes a second outer surface 418a and a second mating surface or curved surface 420e. One of the first and second mating surfaces 414e, 420e is concave and the other of the first and second mating surfaces 414e, 420e is convex.

[0128] The first body 410e of the first section 402e defines a first longitudinal recess 440 and a first circumferential recess 442a. The first longitudinal recess 440 and the first circumferential recess 442a are in fluid communication. The second body 416e of the second section 404e defines a second longitudinal recess 446 and a second circumferential recess 448a. The second longitudinal recess 446 and the second circumferential recess 448a are in fluid communication.

[0129] The first and second longitudinal recesses 440, 446 cooperate to define a longitudinal passage (see, for example, longitudinal passage 452 of Fig. 5A). The first and second circumferential recesses 442a, 448a cooperate to define a circumferential receptacle (see, e.g., circumferential receptacle 454a of Fig. 5A). While the gear box 400e is shown as an open-type gear box, in other implementations the gear box 400e may further include walls similar or identical to the walls 444, 446 of the gear box 400 of Fig. 4A- Fig. 4E and be a closed-type gear box. The gear box 400e may also include third and fourth openings 464, 466 for receiving fasteners.

[0130] The second portion 404e may include two pins 470d. The first portion 402d may include two receptacles 472d. When the gear box 400e is in an assembled or pre-assembled configuration, the receptacles 472d receive the pins 470d. The gear box 400e may be symmetrical about a plane extending through a central axis 912 and between a top surface 914 and a bottom surface 916 of the gear box 400e. The gear box 400e may be free of pre-assembly connection stop features (e.g., one or more pairs of annular projections and recesses 480, 482, as shown at least in Fig. 8A- Fig. 9 shown). Elastic layer

[0131] A gear box according to the principles of the present disclosure may further include an elastic layer on a first mating surface and / or a second mating surface. The elastic layer may be referred to in various implementations as an elastic compensation element. The elastic layer facilitates the accommodation of relatively large manufacturing tolerances in the bodies of the gear box sections, and particularly in the mating surfaces. An elastic layer may be particularly advantageous when used in a gear box without pre-assembly connection stop features (see, e.g., gear box 400e of Fig. 10), but can also be used in gear boxes with pre-assembly connection stop features (see, for example, gear boxes 400a, 400d). The elastic element can comprise an elastic material, such as nitrile butadiene rubber, with a predefined compression hardness.

[0132] With reference to Fig. 11A-11B, another gear box 400f is illustrated. The structure and function of gear box 400f may be substantially similar to that of gear box 400e, except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals including letter extensions (i.e., "f") are used to identify those features that have been modified.

[0133] The gear box 400f includes a first part or section 402e and a second part or section 404f. A boundary or connection 406f between the first and second sections 402e, 404f defines a three-dimensional curve, such as a section of an ellipsoid, a cone, or a sphere. The first section 402e includes a first body 410e, and the second section 404f includes a second body 416e. The first and second bodies 410e, 416e include first and second mating surfaces 414e, 420e, respectively.

[0134] The second portion 404f further includes an elastic layer 1100. The elastic layer 1100 may be disposed on the second mating surface 420e, such as directly on the second mating surface 420e. The elastic layer 1100 may be coupled to the second mating surface 420e. The elastic layer 1100 may have a substantially uniform thickness. For example, the elastic layer 1100 may define a thickness 1102 in the range of 0.5 mm to 1 mm in an assembled state.

[0135] In other implementations, an elastic layer may additionally or alternatively be present on a first mating surface of a second portion. The use of an elastic layer, such as elastic layer 1100, may be equally applicable to open- or closed-type gear boxes having any mating surface curvature (e.g., ellipsoidal, conical, spherical) and any number of pre-assembly connection stop features, including none. Fasteners

[0136] A gear box assembly according to the principles of the present disclosure may include any of the gear boxes discussed above and a plurality of fasteners. The fasteners may include, for example, screws, rivets, and / or bolts. Rivets may be discrete components separate from the gear box portions. Additionally or alternatively, one or both of the first and second portions may include built-in or integrated rivets. A gear box may include more than one type of fastener, such as any combination of the fasteners described herein.

[0137] With reference to Fig. 12A-12C, a gear box assembly 1200 is provided in accordance with the principles of the present disclosure. The gear box assembly 1200 includes the gear box 400a (see Fig. 5A-5B and the accompanying discussion) and a plurality of fasteners 1202. The fasteners 1202 may include screws, such as self-tapping screws. In some implementations, the plurality of fasteners 1202 may include four fasteners.

[0138] How best in Fig. 12B, each fastener 1202 may include a shaft 1204, a head 1206, and a thread 1208 extending along at least a portion of the shaft 1204. The shaft 1204 may extend through third and fourth openings 464, 466. The head 1206 may be at least partially disposed within a counterbore 1210 in the second body 416a such that an end 1212 of the head 1206 is flush with at least a portion of the outer surface 412a of the second body 416a. The thread 1208 may engage a surface 1214 of the third opening 464 to couple the first and second portions 402a, 404a together. In the assembled configuration, as shown in Fig. 12C, the pins 470 and the annular projections 480 may be disposed in the receptacles 472 and the annular recesses 482, respectively. In other implementations, an orientation of the screws 1202 may be reversed such that the head 1206 engages the first body 410a and the thread 1208 engages the second body 416a.

[0139] Although Fig. 12A- Fig. 12C illustrate the gear box assembly 1200 including the open-type gear box with ellipsoidal mating surfaces and dual pre-assembly connection stop features, the use of screws is equally applicable to assemble other gear boxes according to the principles of the present disclosure. For example, a gear box assembly may include screws and a gear box that is (i) open-type or closed-type, (ii) has ellipsoidal, conical, spherical, or other three-dimensional curved mating surfaces, (iii) includes zero, one, two, or more than two pre-assembly connection stop features, and (iv) includes or is devoid of an elastic layer.

[0140] With reference to Fig. 13A-13D, a gear box assembly 1300 is provided in accordance with the principles of the present disclosure. The gear box assembly 1300 includes the gear box 400e (see Fig. 10 and the accompanying discussion) and a plurality of fasteners 1302. The fasteners 1302 may include rivets. Prior to assembly and deformation, each of the rivets may be a distinct and separable component. In some implementations, the plurality of fasteners 1302 may include four rivets.

[0141] How best in Fig. 13C, each fastener 1302 may include a shaft 1304 and a head 1306. The shaft 1304 may include an end piece 1308 configured to be buckled, swaged, or deformed to form a secondary head 1308', thereby transitioning the fastener 1302 from an undeformed state to a deformed state. The shaft 1304 may extend through third and fourth openings 464, 466. The head 1306 may be at least partially disposed within a counterbore 1310 in the first body 410e such that an end 1312 of the head 1306 is flush with at least a portion of the first outer surface 412a of the first body 410e.

[0142] When the rivets 1302 are in the undeformed state as shown in Fig. 13A- Fig. 13C, the end piece 1308 protrudes beyond the second outer surface 418a. When the rivets 1302 are in a deformed state, as shown in Fig. 13D, the secondary head 1308' may be disposed in a counter-counterbore 1314 in the second body 416e such that an end 1316 of the secondary head 1308' is flush with the second outer surface 418a of the second body 416e. In the deformed state, the rivets 1302 hold the gear box 400e in the assembled state by coupling the first and second portions 402e and 404e together. In other implementations, an orientation of the rivets 1302 may be reversed such that the head 1306 engages the second body 416e and the secondary head 1308' engages the first body 410e.

[0143] Although Fig. 13A- Fig. 13D illustrate the gear box assembly 1300 including the open-type gear box with ellipsoidal mating surfaces and free of pre-assembly connection stop features, the use of rivets is equally applicable to the assembly of other gear boxes according to the principles of the present disclosure. For example, a gear box assembly may include rivets and a gear box that is (i) open-type or closed-type, (ii) has ellipsoidal, conical, spherical, or other three-dimensional curved mating surfaces, (iii) includes zero, one, two, or more than two pre-assembly connection stop features, and (iv) includes or is free of an elastic layer.

[0144] With reference to Fig. 14A-14D, a gear box assembly 1400 is provided in accordance with the principles of the present disclosure. The gear box assembly 1400 includes a gear box 400g with integrated rivets. The structure and function of the gear box 400g may be substantially similar to that of the gear box 400a, except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals including letter extensions (i.e., "g") are used to identify those features that have been modified.

[0145] The gear box 400g includes a first part or section 402g and a second part or section 404g. A boundary or connection 406g between the first and second sections 402g, 404g defines a portion of a three-dimensional curve, such as an ellipsoid, a cone, or a sphere. The first section 402g includes a first body 410g. The first body 410g includes a first outer surface 412a and a first mating surface or curved surface 414g. The second section 404g includes a second body 416g. The second body 416g includes a second outer surface 418a and a second mating surface or curved surface 420g. One of the first and second mating surfaces 414g, 420g is concave and the other of the first and second mating surfaces 414g, 420g is convex. Curvatures of the first and second mating surfaces 414g, 420g are substantially equal and opposite.

[0146] The first body 410g of the first section 402g defines a first longitudinal recess 440 and a first circumferential recess 442a. The first longitudinal recess 440 and the first circumferential recess 442a are in fluid communication. The second body 416g of the second section 404g defines a second longitudinal recess 446 and a second circumferential recess 448a. The second longitudinal recess 446 and the second circumferential recess 448a are in fluid communication. The first and second longitudinal recesses 440, 446 cooperate to define a longitudinal passage 452 ( Fig. 14B). The first and second circumferential recesses 442a, 448a cooperate to define a circumferential receptacle 454a ( Fig. 14B). While the gear box 400g is shown as an open-type gear box, in other implementations the gear box 400g may have walls similar or identical to the walls 444, 446 of the gear box 400 of Fig. 4A- Fig. 4E and be a closed type gear box.

[0147] The second portion 404g may include a first pair of integrated rivets 1402 and a second pair of integrated rivets 1404. The first and second pairs of rivets 1402, 1404 may be integrally formed with the second body 416g. The first and second pairs of rivets 1402, 1404 may extend from the second mating surface 420g. The rivets 1402, 1404 may have circular or oval cross-sections. In the illustrated implementation, the rivets 1402 of the first pair have circular cross-sections and the rivets 1404 of the second pair have oval cross-sections.

[0148] The first portion 402g may include a first pair of rivet openings 1406 and a second pair of rivet openings 1408. The first and second pairs of rivet openings may be defined in the first mating surface 414g. The rivet openings 1406, 1408 may have cross-sectional shapes that match respective cross-sectional shapes of the rivets 1402, 1404. In the example shown, the rivet openings 1406 of the first pair have a circular cross-section, and the rivet openings 1408 of the second pair have an oval cross-section.

[0149] The first and second pairs of rivet openings 1406, 1408 may be configured to receive the first and second pairs of rivets 1402, 1404, respectively. Before deformation, the rivets 1402, 1404 may protrude beyond the first outer surface 412a in a pre-assembled configuration, as shown in Fig. 14B- Fig. 14C. In an assembled configuration, the rivets 1402, 1404 are buckled, compressed, or deformed into a deformed state. In particular, respective first and second end pieces 1410, 1412 ( Fig. 14C) of the rivets 1402, 1404 of the first and second pair into respective first and second heads 1410', 1412' ( Fig. 14D). The first and second heads 1410', 1412' may be disposed in respective first and second counter-countersinks 1414, 1416 in the first outer surface 414a.

[0150] In other implementations, the positions of the rivets and rivet holes may be reversed, so that the first section contains rivets and the second section contains rivet holes. In some implementations, both the first and second sections contain rivets and rivet holes.

[0151] Although Fig. 14A- Fig. 14D illustrate the gear box assembly 1400 including the open-type gear box with dual pre-assembly connection stop features, the inclusion of integrated rivets is equally applicable to the assembly of other gear boxes according to the principles of the present disclosure. For example, a gear box assembly may include integrated rivets on a gear box that (i) is of the open-type or closed-type design, (ii) has ellipsoidal, conical, spherical, or other three-dimensional curved mating surfaces, (iii) includes zero, one, two, or more than two pre-assembly connection stop features, and (iv) includes or is devoid of an elastic layer. Gear arrangements

[0152] Gearboxes according to the principles of the present disclosure are configured to accommodate a variety of different gear assembly configurations. In various implementations, two differently sized universal gearboxes are configured to accommodate gear systems incorporating any combination of the following features. For example, gearboxes according to the principles of the present disclosure may (i) include a cross-axial single enveloping gear system or a cross-axial helical gear system, (ii) have normal strength, enhanced strength, high strength, or very high strength, and (iii) be configured to operate within a comfort speed range, a high speed range, or a very high speed range.

[0153] A cross-axial single-enveloping gear system includes a worm and a single enveloping gear that are operatively engaged and configured to rotate about perpendicular axes. The cross-axial single-enveloping gear system can be robust and cost-effective. In the cross-axial single-enveloping gear system, a gear ratio of the worm to the single enveloping gear can be one of 8.5, 7.5, 6.5, 5.667, 5.333, 4.667, 4.333, 3.667, or 3.333. A cross-axial helical gear system includes a worm and a helical gear that are operatively engaged and configured to rotate about perpendicular axes. In a cross-axial spiral gear system, the gear ratio of the worm to the spiral gear can be one of 3.333, 3.25, 3.2, 2.833, 2.8, 2.75, 2.6, 2.4, or 2.2. A cross-axial spiral gear system can be configured for smoother operation than a cross-axial single-envelope gear system.

[0154] A normal-strength externally driven length adjustment system contains a lead screw capable of withstanding axial forces (e.g., vehicle impact forces) of at least 19 kN. The lead screw for the normal-strength externally driven length adjustment system may have trapezoidal threads designated by Tr 8x3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread pitch). An increased-strength externally driven length adjustment system contains a lead screw capable of withstanding axial forces of at least 25 kN. The lead screw for the increased-strength externally driven length adjustment system may have trapezoidal threads defined by Tr 9x3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread pitch). A high-strength, externally driven length adjustment system includes a lead screw capable of withstanding axial forces of at least 37 kN.The lead screw for the high-strength, externally driven length adjustment system can have trapezoidal threads designated Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch, and 2 mm thread pitch). A very high-strength, externally driven length adjustment system includes a lead screw capable of withstanding an axial force of at least 45 kN. The lead screw for the very high-strength, externally driven length adjustment system can have trapezoidal threads designated Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch, and 2 mm thread pitch).

[0155] Rotational speed classifications may be achieved through a combination of gear ratio and motor parameters (e.g., rotational speed). In various implementations, a gear box according to the principles of the present disclosure may accommodate gear systems with linear adjustment speeds ranging from 17 mm / s to 90 mm / s. In one implementation, a comfort speed system may be configured according to the invention to have an average linear adjustment speed in the range of 17 to 22 mm / s. The comfort speed system may have a maximum electric motor rotational speed of approximately 5,500 rpm. The comfort speed system may have a gear ratio of at least 6.5:1 (e.g., 8.5, 7.5, or 6.5).In another implementation, a high-speed system may be configured according to the invention to have an average linear adjustment speed in the range of 55 mm / s to 60 mm / s. The high-speed system may have a maximum electric motor rotational speed of about 5,500 rpm. The high-speed system may have a gear ratio of at least 3.2 (e.g., 3.2, 3.25, 3.333, 3.667, 4.333, 4.667, 5.333, or 5.667). In yet another implementation, a very high speed system may be configured according to the invention to have an average linear adjustment speed in the range of 85 mm / s to 90 mm / s. The very high speed system may have a maximum electric motor rotational speed of about 5,500 rpm. The very high speed system can have a gear ratio of at least 2.2 (e.g. 2.2, 2.4, 2.6, 2.75, 2.8 or 2.833).

[0156] The externally powered, open-architecture seat length adjustment systems of the present disclosure utilize advantageous combinations of electric motor rotation speed and gear ratios that allow the vehicle seat position to be adjusted at desired linear speeds. Furthermore, the use of a motor with a maximum rotation speed of 5,500 rpm will reduce overall system noise and enable the implementation of a motor sensorless positioning (SLP) function that requires measurement of the motor ripple current amplitude.

[0157] A universal gear box according to the principles of the present disclosure can accommodate any combination of the above gear types, strengths, and speeds. That is, two sizes of a single gear box design can be provided in a configuration variation to subsequently accommodate any combination of the above options. Example implementations are described below.

[0158] With reference to Fig. 15A-15D, an adjustment assembly 24h is provided in accordance with the principles of the present disclosure. The structure and function of the adjustment assembly 24h may be substantially similar to that of the adjustment assembly 24 ( Fig. 1-3), except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals containing letter extensions (i.e., "h") are used to identify those features that have been modified.

[0159] The adjustment assembly 24h includes a spindle screw or lead screw 56h with external threads 66h and an adjustment subassembly 58h. The adjustment subassembly 58h includes a first gear or cylindrical worm 80h with helical external threads 82h, a second gear or enveloping worm 86h with external teeth 84h and internal threads 90h, a pair of bearing bushings 78, and a gear box assembly 1200. The gear box assembly 1200 includes a gear box 400a and a plurality of fasteners 1202. The gear box 400a includes first and second sections 402a, 404a. Although not shown, the adjustment subassembly 58h may further include a support frame (e.g., support frame 74 of Fig. 1-3) and a pair of cover shells (e.g. first and second cover shells 116, 118 of Fig. 1-3). The adjustment assembly 24h may alternatively include any of the other gear box assemblies described herein.

[0160] The threads 66h of the spindle screw 56h can be trapezoidal and defined by Tr 9x3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread pitch). The adjustment assembly 24h can have a minimum axial strength of 25 kN and be considered an adjustment assembly of increased strength. The second gear 86h can be a single-enveloping worm gear. Therefore, the adjustment assembly 24h can be considered to have a cross-axial single-enveloping gear system. The adjustment assembly 24h can be configured to be a comfort speed system via gear ratio and motor parameters.

[0161] Alternatively, the threads 66h of the spindle screw 56h can be trapezoidal and defined by Tr 8x3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread lead), and the adjusting arrangement 24h can have a minimum axial strength of 19 kN. In another alternative, the threads 66h of the spindle screw 56h can be trapezoidal and defined by Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead), and the adjusting arrangement 24h can have a minimum axial strength of 37 kN. In yet another alternative, the threads 66h of the spindle screw 56h can be trapezoidal and defined by Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead), and the adjusting arrangement 24h can have a minimum axial strength of 45 kN.

[0162] With reference to Fig. 16A-16E, an adjustment assembly 24i is provided in accordance with the principles of the present disclosure. The structure and function of the adjustment assembly 24i may be substantially similar to that of the adjustment assembly 24 ( Fig. 1-3), except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals containing letter extensions (i.e., "i") are used to identify those features that have been modified.

[0163] The adjustment assembly 24i includes a lead screw or lead screw 56h with external threads 66h and an adjustment subassembly 58i. The adjustment subassembly 58i includes a first gear or cylindrical worm 80i with helical external threads 82i, a second or spiral gear 86i with external teeth 84i and internal threads 90i, a pair of bearing bushings 78, a pair of washers 1600, a gear box assembly 1200, a pair of cover shells 116, 118, and a support frame 74. The gear box assembly 1200 includes a gear box 400a and a plurality of fasteners 1202. The gear box 400a includes first and second sections 402a, 404a. The adjustment assembly 24i may alternatively include any of the other gear box assemblies described herein.

[0164] The spiral gear 86i includes two cylindrical bearing surfaces 162i. The external teeth 84i extend into a space between the bearing surfaces 162i. Each washer 1600 is disposed on a respective one of the bearing surfaces 1602 between the external teeth 84i and a respective one of the bearing bushings 78. Each washer 1600 includes a retention feature, such as a tab 1604, that engages the spiral gear 86. The tab 1604 can reduce or prevent rotation of the washer 1600 relative to the spiral gear 86i.

[0165] The adjustment assembly 24i includes the spindle screw 56h with the thread 66h defined by Tr 9x3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread pitch). The adjustment assembly 24i may have a minimum axial strength of 25 kN and be considered a high-strength adjustment assembly. The second gear 86i may be a spiral gear. Therefore, the adjustment assembly 24i may be considered to have a cross-axial spiral gear system. The adjustment assembly 24i may be configured to be a comfort speed system via gear ratios and motor parameters.

[0166] Alternatively, the threads 66h of the spindle screw 56h can be trapezoidal and defined by Tr 8x3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread lead), and the adjustment arrangement 24i can have a minimum axial strength of 19 kN. In another alternative, the threads 66h of the spindle screw 56h can be trapezoidal and defined by Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead), and the adjustment arrangement 24i can have a minimum axial strength of 37 kN. In yet another alternative, the threads 66h of the spindle screw 56h can be trapezoidal and defined by Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead), and the adjustment arrangement 24i can have a minimum axial strength of 45 kN.

[0167] With reference to Fig. 17A-17D, an adjustment assembly 24j is provided in accordance with the principles of the present disclosure. The structure and function of the adjustment assembly 24j may be substantially similar to that of the adjustment assembly 24 ( Fig. 1-3), except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals containing letter extensions (i.e., "j") are used to identify those features that have been modified.

[0168] The adjustment assembly 24j includes a lead screw or lead screw 56j with external threads 66j and an adjustment subassembly 58j. The adjustment subassembly 58j includes a first gear or cylindrical worm 80j with helical external threads 82j, a second gear or enveloping worm 86j with external teeth 84j and internal threads 90j, a pair of bearing bushings 78, and a gear box assembly 1200. The gear box assembly 1200 includes a gear box 400a and a plurality of fasteners 1202. The gear box 400a includes first and second sections 402a, 404a. The adjustment assembly 24j may alternatively include any of the other gear box assemblies described herein. Although not shown, the adjustment subassembly 58j may further include a support frame (e.g., support frame 74 of Fig. 1-3) and a pair of cover shells (e.g. first and second cover shells 116, 118 of Fig. 1-3) are included.

[0169] The threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 8x3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread lead). The adjustment assembly 24j can have a minimum axial strength of 19 kN and be considered a normal strength adjustment assembly. The second gear 86j can be a single enveloping worm gear. Therefore, the adjustment assembly 24j can be considered to have a cross-axial single enveloping orthogonal gear system. The adjustment assembly 24j can be configured via gear ratios and motor speed to be a high-speed system.

[0170] Alternatively, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 9x3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread lead), and the adjustment assembly 24j can have a minimum axial strength of 25 kN. In another alternative, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch, and 2 mm thread lead), and the adjustment assembly 24j can have a minimum axial strength of 37 kN. In yet another alternative, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch, and 2 mm thread lead), and the adjustment assembly 24j can have a minimum axial strength of 45 kN.

[0171] With reference to Fig. 18A-18D, an adjustment assembly 24k is provided in accordance with the principles of the present disclosure. The structure and function of the adjustment assembly 24k may be substantially similar to that of the adjustment assembly 24 ( Fig. 1-3), except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals containing letter extensions (i.e., "k") are used to identify those features that have been modified.

[0172] The adjustment assembly 24k includes a lead screw or lead screw 56j with external threads 66j and an adjustment subassembly 58k. The adjustment subassembly 58k includes a first gear or cylindrical worm 80k with helical external threads 82k, a second gear or enveloping worm 86k with external teeth 84j and internal threads 90k, a pair of bearing bushings 78, a pair of washers 1600, and a gear box assembly 1200. The gear box assembly 1200 includes a gear box 400a and a plurality of fasteners 1202. The gear box 400a includes first and second sections 402a, 404a. The adjustment assembly 24k may alternatively include any of the other gear box assemblies described herein. Although not shown, the adjustment subassembly 58k may further include a support frame (e.g., support frame 74 of Fig. 1-3) and a pair of cover shells (e.g. first and second cover shells 116, 118 of Fig. 1-3) are included.

[0173] The threads 66j of the spindle screw 56j may be trapezoidal and defined by Tr 8×3 (P1, 5) (8 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread lead). The adjustment assembly 24k may have a minimum axial strength of 19 kN and be considered a normal strength adjustment assembly. The second gear 86k may be a single enveloping worm gear. Therefore, the adjustment assembly 24k may be considered to have a cross-axial single enveloping gear system. The adjustment assembly 24k may be configured to be a high-speed system.

[0174] Alternatively, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 9x3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread lead), and the adjustment assembly 24k can have a minimum axial strength of 25 kN. In another alternative, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch, and 2 mm thread lead), and the adjustment assembly 24k can have a minimum axial strength of 37 kN. In yet another alternative, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch, and 2 mm thread lead), and the adjustment assembly 24k can have a minimum axial strength of 45 kN.

[0175] With reference to Fig. 19A-19D, an adjustment assembly 24m is provided in accordance with the principles of the present disclosure. The structure and function of the adjustment assembly 24m may be substantially similar to that of the adjustment assembly 24 ( Fig. 1-3), except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals containing letter extensions (i.e., "m") are used to identify those features that have been modified.

[0176] The adjustment assembly 24m includes a lead screw or lead screw 56j with external threads 66j and an adjustment subassembly 58m. The adjustment subassembly 58m includes a first gear or cylindrical worm 80m with helical external threads 82m, a second gear or enveloping worm 86m with external teeth 84m and internal threads 90m, a pair of bearing bushings 78, a pair of washers 1600, and a gear box assembly 1200. The gear box assembly 1200 includes a gear box 400a and a plurality of fasteners 1202. The gear box 400a includes first and second sections 402a, 404a. The adjustment assembly 24m may alternatively include any of the other gear box assemblies described herein. Although not shown, the adjustment subassembly 58m may further include a support frame (e.g., support frame 74 of Fig. 1-3) and a pair of cover shells (e.g. first and second cover shells 116, 118 of Fig. 1-3) are included.

[0177] The threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 8x3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch, and 1.5 mm thread lead). The adjustment assembly 24j can have a minimum axial strength of 19 kN and be considered a normal strength adjustment assembly. The second gear 86m can be an enveloping worm gear. Therefore, the adjustment assembly 24k can be considered to have an enveloping orthogonal gear system. The adjustment assembly 24m can be configured to be a very high speed system.

[0178] Alternatively, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 9x3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread lead), and the adjustment arrangement 24m can have a minimum axial strength of 25 kN. In another alternative, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead), and the adjustment arrangement 24m can have a minimum axial strength of 37 kN. In yet another alternative, the threads 66j of the spindle screw 56j can be trapezoidal and defined by Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead), and the adjustment arrangement 24m can have a minimum axial strength of 45 kN.

[0179] With reference to Fig. 20A-20D, an adjustment assembly 24n is provided in accordance with the principles of the present disclosure. The structure and function of the adjustment assembly 24n may be substantially similar to that of the adjustment assembly 24 ( Fig. 1-3), except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals containing letter extensions (i.e., "n") are used to identify those features that have been modified.

[0180] The adjustment assembly 24n includes a spindle screw or lead screw 56j with external threads 66j and an adjustment subassembly 58n. The adjustment subassembly 58n includes a first gear or cylindrical worm 80n with helical external threads 82n, a second gear or enveloping worm 86n with external teeth 84n and internal threads 90n, a pair of bearing bushings 78, a pair of washers 1600, and a gear box assembly 1200n. The gear box assembly 1200n may be a closed-type gear box and may support the gear box 400 (discussed above with reference to Fig. 4A- Fig. 4E) and fasteners 1202. As described above, the gear box 400 includes first and second sections 402, 404. The adjustment assembly 24n may alternatively include any of the other gear box assemblies described herein. Although not shown, the adjustment subassembly 58n may further include a support frame (e.g., support frame 74 of Fig. 1-3) and a pair of cover shells (e.g. first and second cover shells 116, 118 of Fig. 1-3) are included.

[0181] The thread 66j of the spindle screw 56j may be trapezoidal and defined by Tr 11x4 (P2) (11 mm nominal diameter, 4 mm thread pitch, and 2 mm thread lead). The adjustment assembly 24n may have a minimum axial strength of 37 kN and be considered a high-strength adjustment assembly. The second gear 86n may be an enveloping worm gear. Therefore, the adjustment assembly 24n may be considered to have an enveloping orthogonal gear system. The adjustment assembly 24n may be configured to be a very high-speed system.

[0182] With reference to Fig. 21A-21D, an adjustment assembly 24p is provided in accordance with the principles of the present disclosure. The structure and function of the adjustment assembly 24p may be substantially similar to that of the adjustment assembly 24 ( Fig. 1-3), except for any exceptions described below and / or otherwise shown in the figures. Accordingly, the structure and / or function of similar features will not be described again in detail. In addition, like reference numerals are used below and in the drawings to identify like features, while like reference numerals containing letter extensions (i.e., "p") are used to identify those features that have been modified.

[0183] The adjustment assembly 24p includes a spindle screw or lead screw 56j with external threads 66j and an adjustment subassembly 58p. The adjustment subassembly 58p includes a first gear or cylindrical worm 80p with helical external threads 82p, a second gear or enveloping worm 86p with external teeth 84p and internal threads 90p, a pair of bearing bushings 78, a pair of washers 1600, and a gear box assembly 1200p. The gear box assembly 1200p may be a closed-type gear box and may enclose the gear box 400 (discussed above with reference to Fig. 4A- Fig. 4E) and fasteners 1202. As described above, the gear box 400 includes first and second sections 402, 404. The adjustment assembly 24p may alternatively include any of the other gear box assemblies described herein. Although not shown, the adjustment subassembly 58p may further include a support frame (e.g., support frame 74 of Fig. 1-3) and a pair of cover shells (e.g. first and second cover shells 116, 118 of Fig. 1-3) are included.

[0184] The thread 66j of the spindle screw 56j can be trapezoidal and defined by Tr 12x4 (P2) (12 mm nominal diameter, 4 mm thread pitch, and 2 mm thread lead). The adjustment assembly 24p can have a minimum axial strength of 45 kN and be considered a very high strength adjustment assembly. The second gear 86p can be an enveloping worm gear. Therefore, the adjustment assembly 24p can be considered to have an enveloping orthogonal gear system. The adjustment assembly 24p can be configured to be a very high speed system.

[0185] Fig. 22 illustrates an open architecture of an externally powered seat length adjustment assembly 210 incorporated into the seat assembly 10 of Fig. 1 (instead of the assemblies 24) and has nine different worm-worm gear drives 280a-i / 282a-i that can be swapped into and out of the housing assembly 276 (similar or identical to the housing assembly 76 containing one of the gear boxes described herein) to mate different combinations of gear boxes. According to the invention, for comfort speed (e.g., where the housing assembly 276, worm, and worm gear move linearly along a length of the spindle screw at a speed of 17-22 millimeters per second), an electric motor whose maximum rotational speed is limited to a maximum of 5,500 rpm can be used when paired worm-worm gear drives 280a-c / 282a-c with gear ratios of 6.5, 7.5, and 8.5, respectively, are used. Furthermore, according to the invention, for high-speed easy-entry functionality (e.g.,Where the housing assembly 276, worm, and spiral gears move linearly along a length of the screw at a speed of 55-60 millimeters per second), an electric motor limited to a maximum of 5,500 rpm may be used when paired worm-and-worm gear drives 280d-i / 282d-i with gear ratios of 5.667, 5.333, 4.667, 4.333, 3.667, and 3.333, respectively, are used. As such, a single housing assembly 276 and seat structure with the same architecture and dimensions can be used to achieve the full range of maximum comfort (normal) and high longitudinal adjustment speeds, with vibration and noise in operation within the required limits.

[0186] Fig. Figure 23 illustrates another open architecture of an externally powered seat length adjustment assembly 310 incorporated into the seat assembly 10 of Fig. 1 (instead of the assemblies 24) and has nine different worm-helical gear drives 380a-i / 382a-i that can be swapped into and out of the housing assembly 376 (similar or identical to the housing assembly 76, 276 containing one of the gear boxes described herein) to mate different combinations of gear boxes. According to the invention, for high speed (e.g., where the housing assembly 376, worm, and spiral gear move linearly along a length of the lead screw at a speed of 55-60 millimeters per second), an electric motor at its maximum (e.g., "no torque") rotational speed of 5,500 rpm may be used when paired worm-spiral gear drives 380a-c / 382a-c are used with gear ratios of 3,333 (e.g., the worm 380a may have 3 gears and the spiral gear 382a may have 10 teeth), 3,250 (e.g.,the worm 380b can have 4 gears and the spiral gear 382b can have 13 teeth) or 3,200 (e.g. the worm 380c can have 5 gears and the spiral gear 382c can have 16 teeth) are used. Further, for very high speed applications (e.g., where the housing assembly 376, worm, and spiral gear move linearly along a length of the lead screw at a speed of 85-90 millimeters per second), an electric motor having a maximum rotational speed of 5,500 rpm may be used according to the invention when paired worm-spiral gear drives 380d-i / 382d-i with gear ratios of 2.833 (e.g., the worm 380d may have 6 gears and the spiral gear 382d may have 17 teeth), 2.800 (e.g., the worm 380e may have 5 gears and the spiral gear 382e may have 14 teeth), 2.750 (e.g., the worm 380f may have 4 gears and the spiral gear 382f may have 11 teeth), 2.600 (e.g.,e.g., the worm 380g can have 5 gears and the spiral gear 382g can have 13 teeth), 2,400 (e.g., the worm 380h can have 12 teeth and the spiral gear 382h can have 5 teeth), and 2,200 (e.g., the worm 380i can have 5 gears and the spiral gear 382i ​​can have 11 teeth), respectively. As such, a single housing assembly 376 and seat structure with the same architecture and dimensions can be used to achieve the full range of high speed and very high speed longitudinal setting speeds, while keeping vibration and noise in operation within the required limits. The gear ratios listed above allow the use of a relatively low rotational speed motor (e.g., a maximum of 5,500 rpm) while still providing the desired speed ranges and while reducing noise and improving quality.

[0187] The externally powered, open-architecture seat length adjustment systems of the present disclosure utilize advantageous combinations of electric motor rotation speed and gear ratios that allow the vehicle seat position to be adjusted at desired linear speeds. Furthermore, the use of a motor with a maximum rotation speed of 5,500 rpm will reduce overall system noise and enable the implementation of a motor sensorless positioning (SLP) function that requires measurement of the motor ripple current amplitude.

[0188] According to the principles of the present disclosure, an externally driven seat length adjustment assembly may include a gear box assembly, a gear system, and a lead screw. The gear box assembly may include a gear box and a plurality of fasteners. The gear box may be an open-type gear box or a closed-type gear box. The gear box may include two parts or sections having mating surfaces with three-dimensional curvature, such as ellipsoidal, conical, or spherical. The fasteners may include screws (e.g., self-tapping screws), rivets (e.g., discrete rivets, integrated rivets), bolts, or any combination thereof. The gear system may be an enveloping orthogonal gear system or a helical orthogonal gear system.The transmission system can be configured as a comfort speed system, a high speed system, or a very high speed system. The lead screw can be a standard strength lead screw or a high strength lead screw.

[0189] It is understood that each of the arrangements of Fig. 15A- Fig. 19D, Fig. 22 and Fig. 23 the gear box of the closed type 400 instead of the Fig. 15A- Fig. 19D, Fig. 22 and Fig. 23 shown gear boxes of the open type. Furthermore, each of the arrangements of Fig. 20A- Fig. 21D may include the open type gear box instead of the closed type gear box shown. List of reference symbols: 10 Seating arrangement 12 Backrest 14 Seat 16 Seat rail arrangement 20 lower rail 22 upper rail 24 Arrangement 26 Fastening element 28 Fastening element 32 Fastening element 50 carriage arrangement 54 Drive arrangement 56 spindle screw 58 Adjustment subassembly 62 front end 64 rear end 66 threads 68 front spindle bracket 70 rear spindle bracket 74 support frames 76 Housing arrangement 78 bearing bush 80 first gear 82 external thread 84 external teeth 86 spiral gear 90 internal thread 100 Base of a support frame 102 walls of a support frame 104 Flange 106 Interior Region 114 Gear box 116 Cover shell 118 Cover shell 124 inner shell region 126 inner shell region 130 Section of the gear box 134 Longitudinal recess 138 Opening 140 curved fitting surface 142 Fastening element 150 first end 152 second end 154 first end 156 second end 160 through hole 162 bearing surface 166 gear passage 276 Housing arrangement 376 Housing arrangement 380 snail 400 gear box 402 Gear box section 404 Gear box section 406 Boundary between first and second section of the gear box 408 Ellipsoid 410 first body 412 first outer surface 414 Pass surface 416 second body 420 second body 422 radial outer side 424 radial inside 440 first longitudinal recess 442 second circumferential recess 444 Wall 446 Wall 448 second circumferential recess 450 wall 452 Longitudinal passage 454 circumference recording 460 second opening 462 second opening 464 third opening 466 Opening 470 fasteners or pins 472 recordings 480 wells 482 recesses 500 Outer region 502 circumferential opening 600 pins 700 balls 800 distal end of the pin 802 first connecting surface 804 second connecting surface 806 proximal end 808 distal end of the recording 810 third connecting surface 812 fourth connecting surface 814 second connecting surface 900 Base 902 distal end 904 first connecting surface 906 proximal end 910 second connecting surface 912 center axis 914 top 916 bottom 920 second page 1100 elastic layer 1200 gear box arrangement 1202 screw 1204 Wave 1206 Head of a fastener 1208 thread 1210 counter sink 1300 gear box arrangement 1302 rivets 1304 Wave 1306 Head of a fastener 1308 end piece 1310 counter sink 1400 gear box arrangement 1402 rivets 1404 rivets 1406 rivet opening 1408 rivet opening 1410 end piece 1410' Head of a rivet 1410 end piece 1412' Head of a rivet 1414 counter sink 1416 counter sink 1600 washer 1602 bearing surface

Claims

[1] A vehicle seat adjustment mechanism comprising: a gear box (400); a first gear (80n, 80p) received in the gear box (400) and rotatable relative to the gear box (400) about a first axis; a spindle screw (56j) selected from the group consisting of: a first spindle screw (56j) with trapezoidal thread (66j) and defined by Tr 8×3 (P1.5) (8 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread pitch), a second spindle screw (56j) with trapezoidal thread (66j) and defined by Tr 9×3 (P1.5) (9 mm nominal diameter, 3 mm thread pitch and 1.5 mm thread pitch), a third spindle screw (56j) with trapezoidal thread (66j) and defined by Tr 11×4 (P2) (11 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead), and a fourth spindle screw (56j) with trapezoidal thread (66j) and defined by Tr 12×4 (P2) (12 mm nominal diameter, 4 mm thread pitch and 2 mm thread lead); and a second gear (86n, 86p) received in the gear box (400) and rotatable relative to the gear box (400) about a second axis perpendicular to the first axis, the first gear (80n, 80p) and the second gear (86n, 86p) being in meshing engagement with each other, and the second gear (86n, 86p) having a spindle nut having an internal thread (90) adapted to the selection of the spindle screw (56k), the spindle screw (56j) being in meshing engagement with the internal thread (90) of the second gear (86n, 86p) and extending through the second gear (86n, 86p) along the second axis; wherein the vehicle seat adjustment mechanism further comprises a motor driving the first gear (80n, 80p), the motor having a maximum rotational speed of 5,500 revolutions per minute, wherein the gear box (400), the first gear (80n, 80p) and the second gear (86n, 86p) are configured to move along the second axis at one of: (i) a comfort speed with a linear adjustment speed in the range of 17 mm / s to 22 mm / s, (ii) a high speed with a linear adjustment speed in the range of 55 mm / s to 60 mm / s, or (iii) a very high speed with a linear adjustment speed in the range of 85 mm / s to 90 mm / s, wherein a gear ratio of the first gear (8on, 80p) to the second gear (86n, 86p) is selected from the group consisting of: 8.5, 7.5, 6.5, 5.667, 5.333, 4.667, 4.333, 3.667, 3.333, 3.25, 3.2, 2.833, 2.8, 2.75, 2.6, 2.4 and 2.2, and wherein the spindle screw (56j) has a minimum axial strength of 19 kN. [2] The vehicle seat adjusting mechanism according to claim 1, wherein the first gear (80n, 80p) is a cylindrical worm gear and the second gear (86n, 86p) is one of a spiral gear or a single enveloping worm gear. [3] The vehicle seat adjustment mechanism according to claim 1, wherein the gear box (400) comprises: a first portion including a first body, the first body defining a first longitudinal recess and a first circumferential recess in fluid communication with the first longitudinal recess; and a second portion including a second body, the second body defining a second longitudinal recess and a second circumferential recess in fluid communication with the second longitudinal recess. [4] The vehicle seat adjustment mechanism according to claim 3, wherein: the first body contains a first curved surface which is concave, the second body includes a second curved surface, the second curved surface being convex and having an equal and opposite curvature compared to the first curved surface, and in an assembled configuration: the first curved surface is in contact with the second curved surface, the first longitudinal recess communicates with the second longitudinal recess to define a longitudinal passage, and the first circumferential recess communicates with the second circumferential recess to define a circumferential receptacle. [5] The vehicle seat adjustment mechanism of claim 4, wherein the first curved surface and the second curved surface both define (i) a portion of an ellipsoidal surface, (ii) a portion of a conical surface, or (iii) a portion of a spherical surface. [6] The vehicle seat adjustment mechanism according to claim 5, wherein: one of the first portion and the second portion includes a frustoconical projection extending from a respective one of the first curved surface and the second curved surface, the other of the first portion and the second portion includes a frustoconical receptacle defined by a respective one of the first curved surface and the second curved surface, and in the assembled configuration, the frustoconical receptacle receives the frustoconical projection. [7] The vehicle seat adjustment mechanism according to claim 6, wherein: one of the first portion and the second portion further includes an annular projection extending from the respective one of the first curved surface and the second curved surface, the annular projection being disposed around a base of the frustoconical projection and coaxial with the frustoconical projection, the other of the first portion and the second portion further includes an annular recess defined by a respective one of the first curved surface and the second curved surface, the annular recess being coaxial with the frustoconical receptacle, and in the assembled configuration, the annular recess receives the annular projection. [8] The vehicle seat adjustment mechanism of claim 7, wherein the frusto-conical projection includes a first frusto-conical projection and a second frusto-conical projection, the frusto-conical receptacle includes a first frusto-conical receptacle and a second frusto-conical receptacle, the annular projection includes a first annular projection and a second annular projection, and the annular recess includes a first annular recess and a second annular recess. [9] The vehicle seat adjustment mechanism according to claim 4, further comprising an elastic layer disposed on at least one of the first curved surface or the second curved surface. [10] The vehicle seat adjustment mechanism according to claim 4, wherein: one of the first portion and the second portion includes an integrated rivet extending from a respective one of the first curved surface and the second curved surface, and the other of the first portion and the second portion includes an opening defined in a respective one of the first curved surface and the second curved surface, the opening configured to receive a portion of the integrated rivet. [11] The vehicle seat adjustment mechanism according to claim 1, wherein the spindle screw (56j) is the second spindle screw (56j) and has a minimum axial strength of 25 kN. [12] The vehicle seat adjustment mechanism according to claim 1, wherein the spindle screw (56j) is the third spindle screw (56j) and has a minimum axial strength of 37 kN. [13] The vehicle seat adjustment mechanism according to claim 1, wherein the spindle screw (56j) is the fourth spindle screw (56j) and has a minimum axial strength of 45 kN. [14] A seat track assembly comprising the vehicle seat adjustment mechanism of claim 1, and further comprising a lower seat track and an upper seat track configured to engage the lower seat track and slide along a length of the lower seat track, wherein the gear box (400) is configured to be mounted to the upper seat track.

Images