Automatic free-coasting freewheel apparatus
11226016 · 2022-01-18
Assignee
Inventors
Cpc classification
F16D41/12
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D41/30
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D41/14
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
F16D41/16
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F16D43/24
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
Abstract
An automatic free-coasting freewheel (AFF) having: a free-coasting state; an engaged state and a freewheeling state, the AFF comprising: a driving member; an inertial unit; a driven member; a freewheeling biasing member; and an axis of rotation defining an axle; wherein the driving member, driven member and inertial unit are coaxially mounted onto the axle and rotatable thereupon, the driving member configured to controllably rotate relative to the inertia unit; the driving and driven members having angular velocities: ω.sub.DRIVING and ω.sub.DRIVEN; and angular accelerations α.sub.DRIVING and α.sub.DRIVEN; the inertial unit further comprising a suspension member configured with at least one set of: a locking member and a free-coasting biasing member; wherein the inertial unit is configured to interact between the driving and the driven member to automatically shift between the states, depending upon α.sub.DRIVING versus a threshold value (α.sub.MIN) and ω.sub.DRIVEN and ω.sub.DRIVING.
Claims
1. An automatic free-coasting freewheel (AFF) having: a free-coasting state; an engaged state and a freewheeling state, the AFF comprising: a driving member; an inertial unit having lag/inertial characteristics; a driven member having at least one engagement surface; a freewheeling biasing member; and an axis of rotation defining an axle, the axis having an axial and a rotation direction; wherein the driving member, driven member and inertial unit are respectively coaxially mounted onto the axle and are rotatable thereupon, the driving member configured to controllably rotate relative to the inertia unit in the rotation direction, depending upon the free coasting, engaged, and freewheeling states; the driving and driven members respectively having respective angular velocities: ω.sub.DRIVING and ω.sub.DRIVEN; and respective angular accelerations α.sub.DRIVING and α.sub.DRIVEN; wherein the inertial unit is positioned between the driving member and the driven member, the inertial unit further comprising a suspension member configured with at least one set of: i. a locking member having a locking member shape and configuration, the locking member configured to engage and disengage the at least one engagement surface; and ii. a free-coasting biasing member configured to act on the locking member to shift it away from the at least one engagement surface; wherein the inertial unit is configured to interact between the driving and the driven member to controllably maintain and to automatically shift between the free-coasting, engaged, and freewheeling states, depending upon α.sub.DRIVING versus a threshold driving member angular acceleration value (α.sub.MIN) and ω.sub.DRIVEN and ω.sub.DRIVING; and wherein α.sub.MIN is adjustable by changes to the lag/inertial characteristics and configuration of the inertial unit; and wherein the freewheeling biasing member is configured to bias the locking member and the engagement surface away from each other in the freewheeling state.
2. The AFF according to claim 1, wherein configuration of additional mechanical components includes at least one chosen from the list including: a clamping member assembly and a magnetic lag assembly.
3. The AFF according to claim 1, having a radial configuration, wherein the suspension member includes at least one set of suspension recesses formed therein, each set including: a locking member recess, in which the locking member is displaceable and configured to engage and disengage the at least one engagement surface; a free-coasting biasing member recess, in which a free-coasting biasing member is positioned; and a freewheeling biasing member recess-passage, in which the freewheeling biasing member is positioned.
4. The AFF according to claim 3, wherein the locking member is configured to be radially displaced and the locking member shape and configuration are configured to decrease an angle of engagement (AOE) value.
5. The AFF according to claim 4, wherein the ratio between dimension D3 and dimensions D2 (D3/D2) defining a lever effect for decreasing the angle of engagement (AOE) value.
6. The AFF according to claim 1, wherein the at least one engagement surface has teeth.
7. The AFF according to claim 1, wherein the at least one engagement surface is a race surface.
8. The AFF according to claim 1, having an axial configuration, wherein the driving member and the suspension member are fixed in the axial direction, wherein the locking member and the suspension member are coaxially mounted onto the axle and configured to be axially displaced and wherein the free-coasting and freewheeling biasing members are configured about the axle.
9. A method of operating an automatic free-coasting freewheel (AFF) having: a free-coasting state; an engaged state; and a freewheeling state, The AFF comprising: a driving member; an inertial unit having lag/inertial characteristics; a driven member having at least one engagement surface; a freewheeling biasing member; and an axis of rotation defining an axle, the axis having an axial and a rotation direction; wherein the driving member, driven member, and inertial unit are respectively coaxially mounted onto the axle and are rotatable thereupon, the driving member configured to controllably rotate relative to the inertia unit in the rotation direction, depending upon the free coasting, engaged, and freewheeling states; the driving and driven members respectively having respective angular velocities: ω.sub.DRIVING and ω.sub.DRIVEN; and respective angular accelerations α.sub.DRIVING and α.sub.DRIVEN; and wherein the inertial unit is positioned between the driving member and the driven member, the inertial unit further comprising a suspension member configured with at least one set of: i. a locking member having a locking member shape and configuration, the locking member displaceable to engage and disengage the at least one engagement surface; and ii. a free-coasting biasing member acting on the locking member to shift it away from the engagement surface; wherein the inertial unit interacts between the driving and the driven member and controllably maintains and automatically shifts between the free-coasting, engaged, and freewheeling states, depending upon α.sub.DRIVING versus a threshold driving member angular acceleration value (α.sub.MIN) and ω.sub.DRIVEN and ω.sub.DRIVING, according to the following steps: shifting from the free-coasting state to the engaged state when α.sub.DRIVING≥α.sub.MIN and when ω.sub.DRIVEN≤ω.sub.DRIVING; shifting from the free-coasting state to the freewheeling state when α.sub.DRIVING≥α.sub.MIN and when ω.sub.DRIVEN>ω.sub.DRIVING; shifting from the engaged state to the freewheeling state when ω.sub.DRIVEN>ω.sub.DRIVING and α.sub.DRIVING≥α.sub.MIN; shifting from the freewheeling state to the engaged state when α.sub.DRIVEN≤ω.sub.DRIVING and α.sub.DRIVING≥α.sub.MIN; shifting from the engaged state to the free-coasting state when α.sub.DRIVING≤α.sub.MIN and ω.sub.DRIVING<ω.sub.DRIVEN; and shifting from the freewheeling state to the free-coasting state when α.sub.DRIVING<α.sub.MIN and ω.sub.DRIVING<ω.sub.DRIVEN; and whereby the freewheeling biasing member biases the locking member and the engagement surface away from each other in the freewheeling state.
10. The AFF according to claim 9, whereby the locking member is radially displaceable.
11. The AFF according to claim 9, whereby the locking member and suspension member are axially displaceable and where the free-coasting and freewheeling biasing members are configured about the axle.
Description
LIST OF FIGURES
(1) The invention is described herein, by way of example only, with reference to the accompanying drawings, wherein:
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DETAILED DESCRIPTION OF DRAWINGS
(21) Embodiments of the current invention relate to the field rotational-based devices with freewheels and specifically to an automatic free-coasting freewheel (AFF). Furthermore, embodiments of the current invention provide for an innovative freewheel configuration, which is automatic, durable, and which has fast engagement features—all as described hereinbelow.
(22) In the specification and claims which follow, the terms “acceleration” and “deceleration”, when applied to a freewheel with respective objects having a respective angular velocity (ω) and respective angular acceleration (α) are applied. Additionally, the term “torque” (τ), yielding angular acceleration α, is used, according to the Newtonian equation, τ=Iα, in which I is the moment of inertia, as known in the art. In the specification and claims which follow, a minimum or threshold, value of any rotational variable (ω, α, τ) is expressed by the subscript “MIN”, i.e. ω.sub.MIN, α.sub.MIN, and τ.sub.MIN. In similar fashion, a variable attributed to a specific part of an AFF (for example, the driving member) uses the specific part name in the subscript and is expressed, for example, as ω.sub.DRIVING.
(23) Regarding sense, the term “forward” (positive value) is used hereinbelow interchangeably to mean “clockwise”. Likewise, “backward” (negative value) is used interchangeably hereinbelow with “counterclockwise”. Therefore, clockwise angular acceleration and clockwise torque have a positive sense and counterclockwise angular acceleration and counterclockwise torque have negative values.
(24) Reference is currently made to
(25) Inertial unit 107 further includes; a suspension member 110: a suspension recesses 112: a locking member 114: a free-coasting biasing member 116 (also referred to hereinbelow as a “non-engagement biasing member 116”): and a freewheeling biasing member 118. Both biasing members are shown in the present figure as exemplary coil-compression springs, but as described hereinbelow, the biasing members may have alternate configurations, such as, but not limited to: a leaf spring; an alternate spring configuration, magnets; and any similar structure/device having similar mechanical spring-like/elasticity behavior.
(26) Reference is currently made to
(27) As shown in the figure, locking member recess 124 is formed to maintain locking member 114 therein, at a first end 124a of locking member recess, having a rounded recess, as shown, mating with and allowing only rotational movement of locking member 114 about a rotational axis 114a, as shown in the figure. A second end 124b of locking member recess 124 is wider than the corresponding mating dimension of locking member 114. As a result, when mated within locking member recess 125, locking member 114 may rotate at the first end about rotational axis 114 a and be arcuately displaced at the second end, allowing locking member 114 at the second end to be controllably alternately extended past and withdrawn within the circumference of inertial unit 107. The arcuate displacement described hereinabove enables the inertial unit, and specifically locking member 114 to controllably engage and disengage engagement surfaces 106 of the driven member (ref
(28) In
(29) When driving member 103 is assembled in position upon the axle and in close proximity to inertial unit 107 (as shown in
(30) Reference is currently made to
(31) As noted previously free-coaster freewheels, in general, and specifically AFF 102, have three states of operation: 1. free-coasting state; 2. engaged state; and 3. freewheeling state.
(32) AFF 102 is configured to allow durable, efficient, automatic, and fast shifting between the three states, as described hereinbelow. Sectional view (b) of
(33) Reference is currently made to
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(35) In view (b) the driving member is presently rotated forward, and has a positive value of α, since, previously, ω=0. Currently, let us assume that α<α.sub.MIN, where α.sub.MIN and other “MIN” values are determined, based on operational and structural characteristics of the AFF. (A discussion of changing operational and structural characteristics of the AFF is presented hereinbelow, related to additional figures.)
(36) In the current case, the inertial unit, due to its moment of inertia, I, “resists” a change in ω. Resultingly, the biasing extension tooth moves forward, as indicated in the figure by the arrow, and biasing extension tooth 135 begins to compress freewheeling biasing member 118 and to partially displace locking member 114—but not enough to shift, because α<α.sub.MIN.
(37) Continuing with scenario 1, in view (c), as the driving member continues having an acceleration α<α.sub.MIN, compression of the freewheeling biasing member is not sufficient to affect a shift (displace the locking member) and the inertial unit rotates together with the driving member, both having the same angular velocity=ω. The freewheel remains in the free-coasting state. If driving member continues to have an acceleration α<α.sub.MIN, the driving member can increase its ω and rotate faster than the driven member, and the AFF remains in the free-coasting state.
(38) In view (d) the driving member is no longer accelerated (α=0) and rotates forward at constant ω. Then non-engagement biasing member 116 becomes uncompressed (shown schematically in the figure by the two arrows pointing in opposing directions), serving to bias locking member 114 away from engagement surfaces 106 and to further push freewheeling biasing member 118, which in turn pushes upon biasing extension tooth 135 (and driving member 103) in a negative direction (and the suspension member in a positive direction).
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(40) In view (b), which shows the engaged state, the driving member is rotated forward with α.sub.DRIVEN≥α.sub.MIN.
(41) In view (c), the AFF remains in the engaged state, under two conditions: 1. driving member 103 (including biasing extension tooth 135) have sufficient angular acceleration α to counteract an opposing force of non-engagement biasing member 116; and, 2. ω.sub.DRIVEN (ω of the driven member) is not higher than ω.sub.DRIVING (ω of the driving member)—as is common in all freewheels, as previously described hereinabove.
(42) The driving member may rotate at constant positive ω and/or may have a positive α. Alternatively, the driving member may remain stationary if rotation of the driven member is impeded by drag or friction, for example.
(43) In view (d), which shows a continued engaged state, driven member 104, inertial unit 107, and driving member all rotate together forward, having ω=ω.sub.DRIVING (indicated in the figure as ω>0). In this configuration, non-engagement biasing member 116 is biased by the locking member being engaged in engagement surfaces 106 (i.e. being engaged with driven member 104) and the non-engagement biasing member cannot expand/decompress, to allow a shift into the free-coasting state. A shift to the free-coasting state can only occur if locking member 114 is disengaged from engagement surfaces 106, by movement of the driven member forward relative to the locking member—and thereby enabling non-engagement biasing member 116 to expand. The configuration and shift described hereinabove is equally applicable in a radial/tooth configuration of AFF 102 having engagement surfaces 106 and of an axially configured AFF, having a flat race engagement surface as described further hereinbelow.
(44) View (e) shows a free-coasting state, with the driving member having no acceleration and rotating forward, but with ω.sub.DRIVEN>ω.sub.DRIVING. This happens when either one or both of the following occur: 1. ω.sub.DRIVING is reduced; or 2. ω.sub.DRIVEN increases, due to an external acceleration (gravity, wind, etc.) and causing a shift to the free-coasting state.
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(46) In view (a)—free-coasting—the driven member rotates forward and the driving member either remains stationary (ω=0), rotates backward (if allowed), or rotates forward with a constant angular velocity (ω>0).
(47) View (b) shows the freewheeling state, with the driving member having at least the minimum angular acceleration (α.sub.DRIVING≥α.sub.MIN). Note that the angular velocity of the driven member in this configuration is higher than that of the driving member (ω.sub.DRIVEN>ω.sub.DRIVING). Because of the relative movement of the driven member versus the driving member, engagement surfaces 106 pass “over” locking member 114 and a characteristic clicking sound of the freewheeling state is heard. Freewheeling biasing members 118 is compressed more in comparison to the engaged state whenever locking member 114 is not engaged in the engagement surfaces.
(48) In view (c), free-coasting state, the driven member still has a higher angular velocity than the driving member (ω.sub.DRIVEN>ω.sub.DRIVING) and the driving member has a reduced angular acceleration (α), meaning the driving member nonetheless experiences an increase in angular velocity, but the AFF remains in the free-coasting state.
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(50) In view (a)—freewheeling—the driving member has at least the minimum angular acceleration (α.sub.DRIVING≥αMIN) and the driven member has a higher angular velocity than that of the driving member (ω.sub.DRIVEN>ω.sub.DRIVING).
(51) In view (b) the AFF is in the engaged state with the driving member having α.sub.DRIVING≥α.sub.MIN and ω.sub.DRIVEN=ω.sub.DRIVING. This has come about, for example, by an increase in ω.sub.DRIVING to match ω.sub.DRIVEN.
(52) The AFF remains in the engaged state in view (c), as shown.
(53) In view (d), the AFF is in the freewheeling state, with (α.sub.DRIVING≥α.sub.MIN) and the driven member having a higher angular velocity than that of the driving member (ω.sub.DRIVEN>ω.sub.DRIVING). The increase in ω.sub.DRIVEN is due to an external source, such as, but not limited to: gravity and wind, as noted hereinabove.
(54) The four scenarios presented in
(55) Reference is currently made to
(56) To attempt a shift from 215 Engaged to 220 Freewheeling, step 234 is evaluated. Both ω.sub.DRIVEN>ω.sub.DRIVING and α.sub.DRIVING≥α.sub.MIN must be satisfied—yielding “YES” to shift to 220 Freewheeling. Otherwise, “NO”—do not shift.
(57) In similar fashion, to attempt to shift from 220 Freewheeling to 215 Engaged, step 236 is evaluated, namely ω.sub.DRIVEN≤ω.sub.DRIVING. If “YES” then to shift to 215 Engaged. Otherwise, “NO”—do not shift.
(58) To attempt to shift from 215 Engaged to 210 Free-Coasting, step 238 is evaluated, namely α.sub.DRIVEN≤α.sub.DRIVING and ω.sub.DRIVING<ω.sub.DRIVEN. If “YES”, then to shift to 210 Free-Coasting. If “NO”—do not shift.
(59) Finally, to attempt to shift from 220 Freewheeling to 210 Free-Coasting, step 240 is evaluated, namely α.sub.DRIVING<α.sub.MIN and ω.sub.DRIVING<ω.sub.DRIVEN. If “YES”, then to shift to 210 Free-Coasting. If “NO”, then do not shift.
(60) The discussion hereabove identifies the freewheeling state and the fact that the condition α.sub.DRIVING≥α.sub.MIN must be satisfied to maintain the AFF in the freewheeling state. In practice, AFF 102 remains in the freewheeling state for only a small portion of time, compared to the time the AFF is in the engaged and free-coasting states. As a result, freewheeling friction that is common in all freewheels (ref
(61) It is noted that AFF 102 is shown in
(62) Specifically, logic flow diagram 200 identifies the three states of operation for both radial and axial AFF configurations in embodiments of the current invention, and the logic flow diagram serving to summarize respective conditions for shifting between the three aforementioned states—as additionally described hereinbelow. Whereas shifting and operation of AFF configurations, according to logic diagram 200, is dependent upon changing accelerations and velocities as described hereinabove, the term “automatic”, in reference the AFF and its operation, is intended to mean in the entire specification and in the claims which follow that the shifting from engage state/freewheeling state back into free-coasting state is made by the mechanism itself without any need from the user to manually shift. One example of such “manual shift” in the case of a bicycle can be if the user need to pedal backwards in order to shift into free-coasting state.
(63) AFF 102 performance can be changed by a number of design/structural changes to the inertial unit to affect α.sub.MIN (minimal angular acceleration)—a key parameter related to shifting from and to the three states of the AFF—or to changing the AOE—related to AFF reaction/shifting speed.
(64) The following exemplary possibilities, among additional possibilities, include: 1. Increasing/decreasing the moment of inertia (I) of the inertial unit (by changing its mass and/or geometry). A higher I value yields a lower α.sub.MIN and a lower I value yields a higher α.sub.MIN. Changing I of the inertial unit may be accomplished by changing the mass of the inertial unit and/or affecting geometric changes (including, for example, a thicker or thinner suspension member). Optionally or alternatively, an increase of the mass, thereby increasing I, may be accomplished by mechanically fixing the suspension member to its own axle segment (thereby adding the mass of the axle segment to the mass of the inertial unit). The inertial unit axle segment would then be allowed to rotate relative to the axle (ref previous figures) using mechanical or magnetic bearings, as known in the art. 2. Increasing/decreasing the spring force (resistance) of the non-engagement biasing member. This can be done by increasing/decreasing the exemplary “k” value (spring constant, as known in the art) and/or by preloading the non-engagement biasing member. A higher spring biasing force yields a higher α.sub.MIN whereas a lower spring force yields a lower α.sub.MIN. It is noted that the description hereinabove is not limited to only a spring biasing member, but to other biasing members, as known the art. 3. In a radial design of AFF 102, increasing/decreasing the geometry/structure of locking member 114 affects α.sub.MIN and AOE. Reference is currently made to
(65) Minimal angular acceleration (α.sub.MIN) is specifically affected by design/structural changes to the inertial unit, as described hereinabove. In general, any change to the inertia unit which serves to impact/change lag/inertial characteristics of the inertial unit may serve to change α.sub.MIN. Two examples, as described hereinbelow, relate to configuring additional mechanical components to change lag/inertial characteristic of the inertial unit.
(66) Reference is currently made to
(67) Magnetic lag assembly 145 is an exemplary, non-limiting embodiment of the current invention where an additional mechanical component is configured to affect α.sub.MIN. Magnetic lag assembly 145 includes: an axle-mounted magnetic ring assembly 148 and an inertial unit-mounted magnetic ring assembly 150, both assemblies configured coaxially with axle 105a and having no contact with one another. In the current figure, axle-mounted magnetic ring assembly 148 is shown configured concentrically, within with the inertial unit-mounted magnetic ring; however, the two rings may optionally be mounted oppositely, with inertial unit-mounted ring 150 configured concentrically within axle-mounted magnetic ring assembly 148, as evident from the discussion which follows hereinbelow.
(68) Referring to view (a) of the current figure, axle-mounted magnetic ring assembly 148 includes: a ring 151, which is mechanically fixed onto axle 105a; and a plurality of magnetic elements 152 mechanically fixed onto ring 151.
(69) Inertial unit-mounted ring 150 includes a plurality of magnets 153 mechanically fixed into suspension member 110 of inertial unit 107, as shown in the figure. Magnets of both axle-mounted magnetic ring assembly 148 and inertial unit-mounted ring 150 are aligned so that respective polarities of the respective rings attract each other. View (b) of the current figure shows the axle-mounted ring assembly and the inertial unit-mounted ring with their magnets aligned, typical of when the axle and the inertial unit have ω=0 and locking member 114 is not engaged.
(70) In view (b) respective rings (and their respective magnets) serve to “delay” relative movement of inertial unit to the axle, even when driving member 103 is rotated forward and a is subsequently applied to biasing extension tooth 135. View (c) shows an instantaneous configuration of the AFF as biasing extension tooth 135 is advanced, serving to engage locking member 114 (as shown schematically by the arrow in the figure), yielding a shift to the engaged state. Immediately following the configuration shown in view (c), the respective magnetic rings are no longer aligned—as there is relative movement between them—with the inertial unit and axle have different W values, indicated schematically in the figure as ω>0.
(71) As the inertial unit rotates relative to axle-mounted magnetic ring assembly 148, the magnetic force between the two respective rings is minimized, as respective magnets are alternately not aligned over time (not shown in the current figure).
(72) Reference is currently made to
(73) As noted hereinabove (ref
(74) In the configuration the current embodiment, a protruding post 165 is mechanically fixed upon and protruding from the driving member, similar to the configuration of biasing extension tooth 135 (ref
(75) Further referring to view (c), clamping member 156 clamps upon axle 105a, as shown by space “S”=0 indicated in the figure. In this configuration, ω=0 for inertial unit 107—the inertial unit is stationary and locking member 114 is not engaged. Referring to view (d): the driving member experiences a (also experienced by biasing extension tooth 135 and protruding post 165) which serves to advance and lock locking member 114 (into the engaged state). The clamping member is then extended/urged open by protruding post 165, as indicated by the small arrow in view (d), causing clamping member 156 to open (opening OP to have a larger dimension that shown in view (c)) and to create a positive space (S>0)—as shown in the figure—thereby unclamping and enabling inertial unit 107 to rotate (ω>0). It is important to note that opening the clamping member is achieved not only by advancing the protruding post 165 against one side (156a) of the clamping member (as shown), but also because the other side of the clamping member 156b (with the clamping member protrusion 158) is lagged. This lagging takes place since the driven member 104 is locked/engaged with the inertia unit 107 (the locking member is engaged) and the characteristic of driven member 104 (and any driven member) is to typically have drag (from an external source), rolling resistance and its own moment of inertia, which all serves to effectively lag one side of the clamping member (156b) while the other side (156a) advance. In this manner, as the driving member, the driven member, the inertia unit and the clamping member rotate forward together in the engaged state, the clamping member is maintained opened and no friction/wear with the axle occurs
(76) When the AFF returns to the free-coasting state (with the protruding member also no longer serving to urge open the clamping member) clamping member 156 and opening OP return to their respective original shapes, due to a spring force of the clamping member. S likewise returns to the zero value, and inertial unit 107 is clamped to the axle (similar to the configuration shown in view (c)).
(77) Embodiments of the current invention include clamping member assembly 155 taking alternate forms and/or alternate configurations to affect the clamping/unclamping effect described hereinabove.
(78) Reference is currently made to
(79) Additionally, as shown in detail B (view “b”) AFF 202 has three exemplary sets of suspension member recesses 212 (similar to suspension member recesses 112 shown in
(80) AFF 202 additional includes a plurality of: recesses; biasing members; biasing extension teeth; and locking members—as described hereinabove. All of the embodiments described hereinabove (ref
(81) In race configuration AFF 202, as opposed to a ratchet configuration of
(82) AFF 202 is configured so that when the locking member engages the engagement surface (i.e. “engaged state”) biasing extension teeth 135 (103) are still able to advance inside biasing extension tooth recess-passage 230 to further deform (elastically) the respective freewheeling biasing members 218 against the respective locking members, thereby providing additional force to enhance traction between the locking member and the race/engagement surface.
(83) One way to increase traction of the locking member with the race as known in the art, is to use biasing members (i.e. exemplary springs) having a higher spring constant to provide greater force of the locking member upon the race. However, in AFF 202 (as opposed to conventional race freewheels, such as sprag clutches), increasing the force of the biasing member as described above, does not concomitantly increase drag, friction, and wear in the freewheel, as the time in the freewheeling state is very short, as described hereinabove.
(84) Reference is currently made to
(85) When assembled, AFF 302 is operated similarly to that described for AFF 202 and AFF 102 hereinabove, which includes interactions of the driving member, driven member, and inertial unit, and shifting between/among free-coasting, engaged, and freewheeling states, subject to the relationship of a.sub.DRIVING and a.sub.MIN, as described hereinabove, ref
(86) As noted hereinabove, driving member 303, driven member 304, inertial unit 307, suspension member 310, locking member 314, free-coasting biasing member 316 and freewheeling biasing member 318 are all free to move in the radial direction—with free-coasting biasing member 316 rotating in unison with suspension member 310, as further described hereinbelow. Driving member 303 and driven member 304 are fixed in an axial direction with an axial displacement “F” (ref view (a)) maintained between the driving and driven member in all operational states (drive, freewheeling, and free-coasting) of AFF 302. Additionally, suspension member 310, is constrained along axis 305a, meaning that while the suspension member freely rotates about axis 305a (in the radial direction) it is stationary/constrained in the axial direction. Locking member 314, may move in both radial and axial directions, as further described hereinbelow.
(87) Summarizing the points above: movement of driving member 303 and driven member 304 is constrained in the axial direction and the driving and driven members are maintained along axis 305a at a fixed axial distance F from one another, with axial and radial movement of the other “sandwiched” elements (including locking member 314, free-coasting biasing member 316 and freewheeling biasing member 318) between the driving and driven members allowed. However, suspension unit 310, configured between the driving and driven members as shown in the current figure, is fixed in the axial direction. Elements which are constrained in the axial direction may be mechanically fixed with: glue/adhesive; washers: spacers: lock nuts; Allen screws; and/or similar mechanical fasteners, as known in the art.
(88) Locking member 314 may translate axially in relation to the axially-fixed suspension member, with free coasting biasing member 316 serving to alternately bias the locking member axially away from the suspension member (when the free-coasting biasing member is extended) and to bias the locking member axially towards the suspension member (when the free-coasting biasing member is compressed). Axial translation of the locking member alternately engages and disengages the locking member with engagement surface 306 of the driven member 304.
(89) As shown in
(90) It is noted that whereas freewheeling biasing member 318 and associated mating parts (including: driving member 303 and locking member 314) are shown in
(91) Reference is currently made to
(92) In view “a”, starting with the free-coasting state, angular velocities of both the driving and driven members may take on any values,) as they may rotate independently of each other. Additionally, it can be seen in view “a” that locking member 314 has not translated axially and is nor contacting driven member 304. Spring extension elements 318a are shown to be displaced, as the driving member displaces the extension elements. To initiate a shift into the engaged state, angular acceleration α.sub.DRIVING, is applied to the driving member, as shown in the view “b”.
(93) In view “b”, the engaged state, the angular acceleration applied (and maintained) on the driving member a.sub.DRIVING exceeds or is equal to a.sub.MIN (indicated as a.sub.DRIVING≥a.sub.MIN in the figure). Locking member 314 has translated axially—as described below—and is presently engaged with driven member 304. By definition, in the engaged state, ω.sub.DRIVING=ω.sub.DRIVEN and spring extension elements 318a are not displaced, as freewheeling biasing member 318 has advanced with the locking member axially along the suspension member, which has displaced/translated the locking member to an engaged state.
(94) View “c” shows the freewheeling state, with locking member 314 biasing axially away from the driven member (and towards the driving member) and is disengaged with driven member 304. Spring extension elements 318a are not displaced and freewheeling biasing member 318 is biasing against translating mating surface 303a.
(95) Shifting from engaged\freewheeling states back to free-coasting state takes place as the locking member 314 unlocks with the engagement surface 306 (under the same conditions shown in the flow diagram
(96) The principles of operating AFF 302 are shared with embodiments of the current invention, as shown and described hereinbelow.
(97) Reference is currently made to
(98) Attention is drawn, for example, to a freewheeling biasing member 418, which is formed having extensions 418a in reversed direction to extensions 318a, shown in freewheeling biasing member 318 of AFF 302. Similar to the configuration of AFF 302, locking member 414 and suspension member 410 of AFF 402 are shaped to allow relative movement between each other, with free-coasting biasing member 416 and the suspension member being positioned concentrically to the locking member. Additionally, freewheeling biasing member 418 is formed to allow it to selectively engage with both the locking member and the driving member. Freewheeling biasing member 418 has at least one deflected extension 418a and at least one recessed indentation 418b along the periphery of the freewheeling biasing member. The at least one deflected extension (418a) allows the freewheeling biasing member to mate with at least one translating mating surface 403a of the locking member 414, and at least one recessed indentation 418b allows the freewheeling biasing member to mate with the at least one biasing extension tooth 435 of the driving member, —all as shown in the views “b” and “a” of
(99) It is noted that whereas freewheeling biasing member 418 and associated mating parts (including: driving member 403 and locking member 414) are shown in
(100) Reference is currently made to
(101) AFF 502 includes: a driving member 503; a driven member 504; engagement surfaces 506 of the driven member, and an inertial unit 507. Similar to the configuration of similar parts in AFF 302 (
(102) AFF 502 is operated similarly to that described for AFF 302 hereinabove, which includes interactions of the driving member, driven member, and inertial unit, and shifting between/among free-coasting, engaged, and freewheeling states, subject to the relationship of a.sub.DRIVING and a.sub.MIN, as described hereinabove, ref
(103) As noted hereinabove, related to all configurations of the driven member, in all embodiments described in the specification and claims which follow, a connection of the driven member with additional elements external to the AFF is to be understood/assumed, even though no such integral connections are described and/or shown hereinbelow. Similarly, in AFF 502, rotating hub 525 (driven by the driven member) in turn serves to drive additional elements external to AFF 502.
(104) Similar to AFF 302 as noted hereinabove, in AFF 502, driving member 503, driven member 504, inertial unit 507, suspension member 510, locking member 514, free-coasting biasing member 516 and freewheeling biasing member 518 are all free to move in the radial direction—with free-coasting biasing member 516 rotating in unison with suspension member 510, as further described hereinbelow. Additionally, rotating hub 525 is free to move in a radial direction. Driving member 503 and rotating hub 525 are fixed in an axial direction and axial dimension “G” (ref view (b)) is maintained in all operational states (drive, freewheeling, and free-coasting) of AFF 502. Additionally, suspension member 510, is constrained along axis 305a, meaning that while the suspension member freely rotates about axis 305a (in the radial direction) it is stationary/constrained in the axial direction. Locking member 514 and driven member 504 may move in both radial and axial directions, as further described hereinbelow.
(105) Summarizing the points above: movement of driving member 503 and rotating hub 525 is constrained in the axial direction and the driving member and rotating hub are maintained along axis 305a at a fixed axial distance G from one another, with axial and radial movement allowed for the other “sandwiched” elements (including locking member 514, driven member 504 free-coasting biasing member 516, and freewheeling biasing member 518) between the driving member and the rotating hub. However, suspension member 510, configured between the driving and driven members, as shown in the current figure, is additionally fixed in the axial direction. Elements which are constrained in the axial direction may be mechanically fixed with: glue/adhesive; washers, spacers, lock nuts; Allen screws; and/or similar mechanical fasteners, as known in the art.
(106) Driven member 504 is formed with at least one longitudinally-aligned rib 504a along its outer surface, the at least one rib configured to slidingly mate with at least one longitudinally-aligned slot 525a in an inner surface of the rotating hub, thereby enabling driven member 504 to be configured concentrically to and to drive rotating hub 525, as shown in the figure, freewheeling biasing member 518 is positioned concentrically within rotating hub 525 and serves to bias driven member 504 axially towards and away from inertial unit 507 during freewheeling state, while the driven member is maintained within the rotating hub, as shown in
(107) Locking member 514, suspension member 510, and driving member 503 are shown in view “c”, but without free-coasting biasing member 516—which is configured concentrically within both the locking and the suspension members (as shown in view “b”). Free-coasting biasing member 516 serves to alternately bias the locking member to and from the suspension member, the suspension member being fixed in the axial direction. Locking member 514 has at least one locking slot 514a formed a to receive at least one suspension protrusion 510a and locking member additionally has at least one locking member protrusion 536, having a slanted termination, which is formed to mate with the translated mating surface 503a—as shown in both views “c” and “b”.
(108) It is seen in view “b” that as the driving member rotates, and depending on its acceleration versus the threshold acceleration α.sub.MIN and the interaction with inertial unit 507, the locking member is translated towards and away from the driving member (and, likewise away and toward the driven member) due to the interaction of at least one locking member protrusion 536 with at least one translated mating surface 503a (which has a matching slanted surface).
(109) It is noted that whereas in
(110) Reference is currently made to
(111) Similar to AFF 502, AFF 602 includes movement of a driving member 603 and a rotating hub 625 being constrained in the axial direction and the driving member and rotating hub are maintained along axis 305a at a fixed axial distance from one another, with axial and radial movement allowed for the other “sandwiched” elements (including a locking member 614 and free-coasting biasing member 616) between the driving member and the rotating hub, with exception of the driven member 604 being fixed to the rotating hub (for example by threading as shown) and the freewheeling biasing member 618 being axially constrained (for example by being glued to the driving member). However, in the current configuration while suspension member 610, configured between the driving and driven members, as shown in the current figure, is additionally fixed in the axial direction, locking member 614 translates axially to engage and disengage driven member 604 from an alternate side than that shown in previous AFF configurations. Elements which are constrained in the axial direction may be mechanically fixed with: glue/adhesive; washers, spacers, lock nuts; Allen screws; and/or similar mechanical fasteners, as known in the art.
(112) As seen in views “a” and “b”, inertial unit 607 includes: locking member 614; free-coasting biasing member 616 and suspension member 610. Functioning of inertial unit 607 is similar to previously described AFF configurations and follows the same shifting operation logic flow diagram of
(113) Driven member 604 is mechanically fixed in relation to rotating hub 625 in both radial and axial movement—meaning that the two rotate together (radially) with no axial translation. Threading 635 is shown in the figure as one way to mechanically fix the driven member with the rotating hub (by tightening the driven member against the end of threading 635) but alternate methods of mechanically fixing the two are possible, such as but not limited to: glue/adhesive; lock nuts; Allen screws; and/or similar mechanical fasteners, as known in the art.
(114) Reference is currently made to
(115) In view “a”, starting with the free-coasting state, angular velocities of both the driving and driven members may take on any values, as they may rotate independently of each other. Additionally, it can be seen in view “a” that locking member 614 has not translated axially and is not contacting driven member 604. To initiate a shift into the engaged state, angular acceleration α.sub.DRIVING is applied to the driving member, as shown in the view “b”.
(116) In view “b”, the engaged state, the angular acceleration applied (and maintained) on the driving member a.sub.DRIVING exceeds or is equal to a.sub.MIN (indicated as a.sub.DRIVING≥a.sub.MIN in the figure). Locking member 614 has translated axially—as described below—and is presently engaged with driven member 604. By definition, in the engaged state, ω.sub.DRIVING=ω.sub.DRIVEN and extension elements 633 are not displaced, as the locking member has compressed free-coasting biasing member 616 and advanced axially along the suspension member, which has displaced/translated the locking member to an engaged state.
(117) View “c” shows the freewheeling state, with locking member 614 biasing axially away from the driven member (and away from the driving member) and is disengaged with driven member 604. Extension elements 633 are not displaced and freewheeling biasing member 618 is biasing against the slanted-edged protrusion 636.
(118) Embodiments of all AFF radial and to axial AFF configurations 302, 402, 502, and 602 described hereinabove not only function according to logic flow diagram 200 of
(119) It is appreciated that the above descriptions are intended only to serve as examples, and that many other embodiments are possible within the scope of the present invention as defined in the appended claims.