CN116771876A - Rotary power transmission with actuator retention feature - Google Patents

Abstract

A rotary power transmission device includes a device housing, a clutch, an actuator, and a retainer. The device housing has an interior in which a plurality of components are received for rotation. A clutch is received within the device housing and has a clutch ring selectively engageable with one of the plurality of components. The actuator has a coil and a plunger that is driven to move along an axis and relative to the clutch. And the retainer has a first portion that engages the device housing and a second portion that radially overlaps the coil and limits axial movement of the coil relative to the device housing.

Description

Rotary power transmission with actuator retention feature

Citation of related application

The application claims the benefit of U.S. provisional application Ser. No. 63/320,863, filed on 3/17 at 2022, the entire contents of which are incorporated herein by reference.

Technical Field

The present application relates generally to rotary power transmissions having an actuator for a clutch and a retaining feature for at least a portion of the actuator.

Background

The electromagnetic actuator has a wire coil (wire coil) that generates an electromagnetic field to drive the plunger and actuate the device (e.g., move the clutch member). The coil is received within a housing that is mounted to the housing of the device. The coil housing is typically mounted by a plurality of separate fasteners and may be held in place by a component that increases the axial length or size of the housing of the device, which is undesirable in many applications. Separate fasteners require added complexity, time and cost to construct and assemble the device.

Disclosure of Invention

In at least some embodiments, a rotary power transmission includes a device housing, a clutch, an actuator, and a retainer. The device housing has an interior in which a plurality of components are received for rotation. A clutch is received within the device housing and has a clutch ring selectively engageable with one of the plurality of components. The actuator has a coil and a plunger that is driven to move along an axis and relative to the clutch. And the retainer has a first portion that engages the device housing and a second portion that radially overlaps the coil and limits axial movement of the coil relative to the device housing.

In at least some embodiments, the coil includes a coil housing and a wire coil within the coil housing, and wherein the first portion extends axially and is received on a portion of the device housing and the second portion extends from the sidewall and overlaps a portion of the coil housing. In at least some embodiments, the first portion of the retainer is press fit onto the outer surface of the device housing. In at least some embodiments, the first portion extends axially and the second portion extends radially from the sidewall. In at least some embodiments, the coil housing has an inboard end adjacent the device housing and the coil housing has an outboard end opposite and axially spaced from the inboard end, and wherein the retainer overlaps a portion of the coil housing between the inboard end and the outboard end and the retainer does not extend axially beyond the outboard end. In at least some embodiments, the coil housing includes a flange extending radially outward and between the inboard end and the outboard end, the flange including a first face received against the device housing, and the flange including a second face engaged by the second portion of the retainer.

In at least some embodiments, the coil has a coil housing and a wire coil within the coil housing, and wherein the first portion of the retainer includes a flange coupled to the device housing and the second portion of the retainer includes a sidewall extending from the flange and overlapping a portion of the coil housing. In at least some embodiments, the device housing includes a groove, and wherein the flange is press-fit into the groove with a friction fit between one surface of the flange and a surface defining the groove. In at least some embodiments, when the plunger is driven for movement, the plunger slides along the annular surface of the device housing and the groove is formed radially inward spaced from the annular surface. In at least some embodiments, the flange extends axially into the slot, and the flange has a radially inner surface and an opposing radially outer surface, wherein at least one of the radially inner surface and the radially outer surface frictionally engages the device housing within the slot.

In at least some embodiments, the coil has a coil housing and a wire coil within the coil housing, and wherein the retainer includes a plurality of inwardly extending flanges defining a second portion of the retainer, wherein each flange radially overlaps the coil housing and circumscribes a portion of the coil housing between the flange and the device housing. In at least some embodiments, the first portion of the retainer is defined by a body from which the flange extends radially inward. In at least some embodiments, the device housing includes a groove that opens to a radially outer surface of the device housing and extends radially into the device housing, and wherein the body is received within the groove. In at least some embodiments, the coil housing is located within the device housing radially inward of the recess, and the flange extends inwardly from the body and radially overlaps a portion of the coil housing. In at least some embodiments, the device housing includes a plurality of circumferentially spaced apart skirts, and wherein the groove is formed in the plurality of skirts and the flange is received circumferentially between adjacent skirts. In at least some embodiments, the body includes a first end and a second end circumferentially spaced from the first end with a gap therebetween.

In at least some embodiments, a rotary power transmission device includes: a device housing having an interior in which a plurality of components are received for rotation; a clutch ring received in the device housing and selectively engageable with one of the plurality of components; an actuator; a retainer. The actuator has a coil housing, a coil within the coil housing, and a plunger driven to move along an axis and relative to the clutch ring to move the clutch ring relative to the device housing. The retainer has a first portion engaging the device housing and a second portion extending radially from the first portion toward the axis, and the second portion radially overlaps the coil housing and limits axial movement of the coil housing relative to the device housing.

In at least some embodiments, the first portion extends axially and engages a portion of the device housing. In at least some embodiments, the first portion is received within a recess in the device housing.

In at least some embodiments, the first portion of the retainer may be conveniently press fit into or onto a portion of the device housing, and the second portion may overlap with a surface of the coil housing to facilitate maintaining the coil housing in a desired location or position relative to the device housing. In at least some embodiments, the retainer can be installed without the need for fasteners, adhesives, bonds, welded joints, or the like.

Drawings

The following detailed description of the preferred embodiments and best mode will be set forth with reference to the accompanying drawings, in which:

FIG. 1 is a schematic illustration of a vehicle driveline assembly;

FIG. 2 is a cross-sectional view of a differential having an electrically actuated clutch, wherein the differential is shown in an open position;

FIG. 3 is a perspective view of a differential including a retainer for a solenoid;

FIG. 4 is a partial cross-sectional view of a portion of FIG. 3;

FIG. 5 is a perspective view of a differential including a retainer for a solenoid;

FIG. 6 is a partial cross-sectional view of a portion of FIG. 5;

FIG. 7 is a perspective view of a differential including a retainer for a solenoid;

FIG. 8 is an exploded perspective view of the differential and the retainer and the solenoid;

FIG. 9 is a partial cross-sectional view of a portion of FIG. 7; and

fig. 10 is a partial cross-sectional view of a portion of fig. 7.

Detailed Description

Referring to the drawings in greater detail, FIG. 1 illustrates a vehicle driveline 12 that is powered from an engine 14 to a plurality of wheels including front wheels 15 and rear wheels 16. The engine 14 supplies torque via a transmission 17 and a power transfer unit 18 that provides an output shaft 20. The output shaft 20 is coupled to a first propeller shaft 21, the first propeller shaft 21 is coupled to a rear drive unit 22, and the rear drive unit 22 may include a differential assembly 23. The power transfer unit 18 or other device may have an output shaft 24, with the output shaft 24 coupled to a front drive unit 25 (which may include a differential assembly 26) via a second propeller shaft 27. The left and right front axles 28, 29 are coupled to drive units/differentials 25, 26 that allow relative rotation between the axles 28, 29 and the front wheels 15. The left and right rear axles 30, 32 are coupled to rear drive units/differentials 22, 23 that permit relative rotation between the axles 30, 32 and the rear wheels 16. The power transfer unit 18 may include a disconnect assembly that, when in a connected state, transfers torque to the second drive shaft 27 to drive the front wheels 15. When connected or disconnected, the power transfer unit 18 may provide torque to the first drive shaft 21 to drive the rear wheels 16. Thus, depending on the state of the disconnect device, the transmission 12 may provide torque to only the rear wheels 16, or to all four wheels 15, 16.

Of course, other driveline configurations may be used as desired. For example, while shown in a rear drive-based driveline, the locking differential may also be used in a front drive-based all-wheel drive system, or even in a two-wheel drive front engine/front wheel drive or front engine/rear wheel drive driveline, and in an e-axle (electric motor driven final drive unit).

Referring now to fig. 2, a first rear axle 30 is connected to a first side gear 34 within differential 23. Similarly, the second rear axle 32 is connected to a second side gear 36 within the differential 23. The side gears 34, 36 are carried within a housing 37 of the differential 23 (which may be referred to as a differential housing or a device housing). The differential also includes pinions 38, 40 that mesh with the side gears 34, 36, respectively, and the pinions 38, 40 are mounted on a pinion shaft 42 within the housing 37.

To selectively lock and unlock differential 23, clutch assembly 46 is provided. The clutch assembly 46 may have actuated and deactuated states, and in one state, the clutch assembly couples one of the side shafts (e.g., 32) to the differential housing 37 such that the coupled side shaft rotates with the housing. This in turn causes the other side shaft 30 to rotate with the housing 37 and the side shaft 32 coupled to the housing such that the two side shafts 30, 32 rotate at the same speed.

In at least some embodiments, the clutch assembly 46 is electrically actuated and includes an actuator having a solenoid 48 with an annular wire coil 49 and a drive member that may include an armature or plunger 54 that is at least partially received radially inward of and axially overlaps the coil 48. In at least some embodiments, the plunger 54 is also annular, the plunger and coil 49 are coaxially disposed and carried by the housing 37 for rotation therewith, and one (here, the second) side shaft extends coaxially through the portion of the housing 37 extending through the coil and plunger. Power is supplied to the coil 49 via the wire 50 to generate a magnetic field that displaces the plunger 54 relative to the coil and differential housing 37 from a first or retracted position to a second or advanced position. To facilitate return of the plunger 54 from the second position to the first position when no power is supplied to the coil 49, a biasing member, such as a spring 55, may act on the plunger 54 or on a component engaged with the plunger, as described below. In at least some embodiments, the clutch assembly 46 is actuated when the plunger 54 is in the second position, and the clutch assembly is deactuated when the plunger is in the first position. While in the illustrated example, the plunger 54 is in its second position when power is supplied to the coil 49 and the plunger moves to the first position when power is not supplied to the coil, the opposite may occur if desired (e.g., the clutch assembly 46 may be moved to the actuated position by the biasing member 55 and deactuated by supplying power to the coil).

In at least some embodiments, the clutch assembly 46 may further include or be associated with a clutch member, referred to herein as a clutch ring 56, the clutch ring 56 being adapted to be driven by the plunger 54 and engaged with the side gear 34, as described below. The clutch ring 56 may be annular and a portion of the second side gear 36 and/or the shaft 32 may extend through the clutch ring. The clutch ring 56 may include a rear face 57 engageable by the plunger 54 and a front face 59 having at least one engagement feature 58, such as a gear or clutch tooth 58 (e.g., a dog clutch tooth), configured to engage a corresponding engagement feature 60 (e.g., a gear or dog clutch tooth) formed on the rear face of the first side gear 34. As described above, when the coil 49 is not energized, the spring 55 may act on the clutch ring 56 to urge the clutch ring into the plunger 54 and move the plunger to its first position. In the illustrated embodiment, the plunger 54 is located adjacent one side of the housing wall 62 and the clutch ring 56 is located adjacent the other side of the wall 62. The wall 62 includes a bore 64 and the plunger 54 and clutch ring 56 include axially extending feet 66, 68, respectively, the feet 66, 68 extending into or through the bore 64 in the wall such that the plunger and clutch ring engage one another across or through the wall. Like the coil 49 and the plunger 54, the clutch ring 56 is also carried by the housing 37 and rotates with the housing 37.

Differential 23 shown in fig. 2 is shown in an open mode or position. In the illustrated embodiment, in the open position of the differential, the coil 49 is not energized, the plunger 54 is in its first position, and the clutch ring 56 is not engaged with the side gear 34, such that the side gear can rotate relative to the clutch ring 56 and the housing 37. In the open position, the side shafts 30, 32 may rotate at different speeds from each other. However, certain driving conditions may require that the sideshafts 30, 32 rotate in unison such that torque is applied to both wheels.

In the locked position, the coil 49 is energized and the plunger 54 advances to its second position, which drives the clutch ring 56 into engagement with the side gear 34 (i.e., the teeth 58 engage and mesh with the teeth 60). Thus, the side gears 34 are coupled to the housing 37 such that the side gears rotate with the housing, rather than with respect to the housing. In effect, the second side shaft 32 is locked to the housing 37 and rotates with the housing 37, which in turn forces the first side shaft 30 and the second side shaft 32 to rotate in unison.

As shown in fig. 2, 4, 6, 9, and 10, the plunger 54 may be formed from a variety of materials, including materials that are magnetically responsive to the magnetic field generated by the coil 49, and at least one other material that may or may not be responsive to the magnetic field. Thus, when a magnetic field is generated by the coil 49, the plunger 54 may be driven from one position to another (e.g., from a retracted position to an advanced position). As used herein, a material is responsive to a magnetic field if a magnetic field of the magnitude generated by a solenoid 48 of the type used in applications such as those described herein can cause a displacement of a component formed from or comprising such material.

In at least some embodiments, as shown in fig. 2 and 3, the plunger 54 includes a body having a central axis 73, and the body may be defined by a first body 74 and a second body 76 that are coupled together and move as a unit or component and do not separate during use. The first body 74 may be formed of magnetically responsive material and may be received adjacent and radially inward of the coil 49 with a small air gap therebetween. The second body 76 may have at least a portion that is radially inward of at least a portion of the first body 74. The second body 76 may be annular and, in at least some embodiments, may radially overlap a portion of the first body 74. The second body 76 may be conveniently overmolded onto the first body 74 to facilitate forming the second body and joining the first and second bodies together, however, other molding processes may be used, such as, but not limited to, casting, stamping, or extrusion. If desired, the second body 76 may define part or all of the foot 66 of the plunger 54, which may extend axially beyond the first body 74. The second body 76 may be formed of a non-magnetically responsive material (e.g., plastic, aluminum, stainless steel, etc.) and may provide various magnetic flux barriers that increase the strength of the magnetic field on the first body 74 or in the region of the first body 74 to ensure proper response of the plunger 54 when the coil 49 is energized. In this way, the magnetic field is more concentrated or stronger in the region of the first body 74 to increase the magnetic flux at or in the first body and to increase the responsiveness of the plunger 54 to the generated magnetic field.

As shown in fig. 2 and 4, the second body 76 may have an inner surface 78, the inner surface 78 being received near or about a surface 79 of the differential housing 37. The inner surface 78 may define a pilot diameter for receiving the plunger 54 on an annular surface 79 of the differential housing 37 to facilitate guided linear axial movement of the plunger relative to the differential housing.

Referring to fig. 2, clutch ring 56 has a body 80, a radially outer surface 84, and a radially inner surface 86, body 80 having a central axis that may be coaxial with axis 73 of plunger 54, radially outer surface 84 extending axially between rear face 57 and front face 59, and radially inner surface 86 may have a smaller axial extent than outer surface 84. The inner surface 86 of the clutch ring 56 may be received around the surface of the side gear 34. The feet 68 of the clutch ring 56 define a portion of the rear face 57, with the feet 68 being circumferentially spaced apart and extending axially from other portions of the rear face 57. Teeth 58 are located on front face 59. The clutch ring 56 may be made of metal, such as alloy steel, chrome molybdenum steel, nickel chrome molybdenum steel, medium/high carbon steel, and the like.

In use of differential 23, bearing 88 is mounted on an outer surface of tubular portion 90 of housing 37. In fig. 2, the bearing 88 is shown in diagrammatic form as a broken line polygon and may include an inner race having an inner surface on a tubular outer surface of the tubular portion, and an outer race received on the inner race. Suitable bearings are known in the art. As shown in fig. 2, the bearing 88 extends radially beyond the surface 79 as the plunger 54 slides in use. By engaging the bearing 88, the plunger 54 is prevented from sliding out of the housing 37. Furthermore, an annular ring may be received on the housing surface 79 axially between the plunger and the bearing. The ring may extend radially and overlap the coil 49 to prevent axial movement of the coil 49 relative to the housing 37.

In the embodiment shown in fig. 3, the coil 49 is received within a housing 92, and the housing 92 may be made of any suitable material, such as various plastics. The housing 92 may be formed of more than one piece to facilitate assembly of the coil 49 into the housing 92, the housing may be molded over the coil, and if desired, the housing may be annular and may completely enclose the coil. In embodiments in which a ring is received on the housing surface 79 to retain the coil, the ring may be press fit onto the surface 79 and abut against the adjacent side of the coil housing 92 such that the coil housing 92 is trapped between the ring and the housing 37. So positioned, the ring occupies some axial portion of the surface 79, requiring a longer surface to provide space for the ring and the full axial travel of the plunger 54.

This increased axial length increases the overall size of the differential housing 37 and presents challenges to the drive train where many components need to be installed in a smaller area. Alternatively, if the other portions of the housing 37 are made smaller to provide space for additional space required by the ring, the strength and torque capacity of one or more portions of the housing 37, clutch ring 56, or other components will be reduced. In the example shown in U.S. patent No. 10,473,203, a plurality of separate clips are used to overlap the coil housing to retain the coil on the differential housing. The installation of a single clip can be time consuming and access to the fasteners used to secure the clip can be difficult, as can the handling and installation of smaller clips and fasteners. Further, the clips and fasteners in this example require radial space between the coil housing and the fasteners (which mount the differential housing to the support via the mounting flange), which can increase the size of the housing.

In fig. 3 and 4, a retainer 100 is provided to inhibit or prevent axial movement of the coil 49 relative to the differential case 37. In at least some embodiments, a first portion of the retainer 100 engages the differential housing 37 and a second portion of the retainer 100 engages the coil housing 92.

In the illustrated embodiment, the retainer 100 is annular and includes a cylindrical and axially extending sidewall 102, the sidewall 102 having a thickness in a radial direction. The sidewall 102 extends from the first end 104 to the second end 106, and the retainer 100 includes a radially inwardly extending flange 108 at the second end 106 of the sidewall 102. The diameter of the radially inner surface 110 of the sidewall 102 is sized to be closely received on the outer surface 112 of the differential case 37 adjacent the coil 49. The retainer 100 may be connected to the housing 37 by a press fit or friction fit, by one or more fasteners, adhesives, welded joints, press fit connectors, stakes, or the retainer may include inwardly extending protrusions that are received in openings or slots of the differential housing 37. In at least some embodiments, the surface 112 on which the sidewall 102 is received has a reduced diameter such that the addition of the retainer 100 does not enlarge the outer peripheral dimension of the housing 37. That is, the outer diameter of the holder 100 may be equal to or smaller than the outer diameter of the portion of the housing 37 axially adjacent to the holder 100. In at least some embodiments, the portion of the differential case 37 to which the coil case 92 is mounted is not under high stress, and thus the reduced thickness of the differential case 37 in this region does not compromise the durability of the case 37. Of course, other arrangements may be used as desired.

When assembled to the housing 37, the flange 108 of the retainer 100 radially overlaps the coil housing 92 and may axially abut against a portion of the coil housing 92. So assembled, the coil housing 92 is axially trapped between the flange 108 and the surface of the differential housing 37. In the example shown, the coil housing 92 includes a radially outwardly extending flange 114, the flange 114 having a first face 116 received against the differential housing 37, a radially outer surface 118, and a second face 120 opposite the first face 116. In assembly, the retainer flange is received on the outer surface 118 and adjacent or against the second face 120 such that the coil housing flange 114 is trapped between the differential housing 37 and the retainer flange 108. In at least some embodiments, the coil housing flange 114 is axially spaced from the outer end 122 of the coil housing (with the inner end 124 of the coil housing being received adjacent to or against the differential housing) by a distance that is at least as great as the axial thickness of the retainer flange 108. Thus, during assembly, the retention flange 108 does not extend axially beyond the outboard end 122 of the coil housing 92, and therefore does not increase the axial dimension of the differential 23.

The retainer 100 may be made of any suitable material, including various metals and plastics, as well as composites. The holder 100 may be lightweight and durable. Further, the single piece retainer 100 may engage circumferentially continuous portions of the coil housing 92 or discrete, spaced apart portions of the housing 92 to securely retain the coil housing 92 to the differential housing 37. The one-piece retainer 100 may be easier to handle and install than multiple clips having multiple fasteners. Although described above as annular, the retainer 100 may be c-shaped with a slot or opening defining a free end of the retainer. In at least some embodiments, the retainer 100 spans more than 180 degrees circumferentially, and in some embodiments, the retainer may span more than 300 degrees such that the ends of the retainer 100 on either side of the gap are spaced apart a distance less than the outer diameter of the portion of the housing 37 on which the retainer is received.

Fig. 5 and 6 relate to a differential that may be constructed and arranged similar to differential 23 described above with respect to fig. 2-4, except as noted herein. For ease of describing this embodiment, the same reference numerals will be used for the same or similar components already described, and the above description is incorporated herein. In fig. 5 and 6, a retainer 130 is provided to inhibit or prevent axial movement of the coil 49 relative to the differential case 37. In at least some embodiments, a first portion of the retainer 130 engages the differential housing and a second portion of the retainer 130 engages the coil housing.

In the illustrated embodiment, the retainer 130 is annular and includes a cylindrical and radially extending sidewall 132, the sidewall 132 having a thickness in the axial direction. The sidewall 132 extends from a first end 134 to a second end 136, and the retainer 130 includes an axially extending flange 138 at the second end 136 of the sidewall 132. The radially inner surface 140 of the sidewall 132 extends radially such that the first end 134 overlaps the coil housing 92 and the inner surface 140 is disposed to contact the outboard end 122 of the coil housing. Further, the side wall 132 radially overlaps the plunger 54 and is axially outward of the plunger 54.

In this embodiment, the retainer is coupled to the differential housing 37 by a flange 138. In at least some embodiments, the differential housing 37 includes a groove 142, and the flange 138 is received in the groove 142. Flange 138 may be attached to housing 37 by a press fit or friction fit, by one or more fasteners, adhesives, welded joints, press fit connectors, stakes, or the like. In at least some embodiments, the radially inner surface 144 or the radially outer surface 146 of the flange 138 is arranged to frictionally engage an adjacent surface of the differential housing 37 within the groove 142. So arranged, when the flange 138 is pressed into the groove 142, the inner surface 140 of the sidewall 132 engages the coil housing 92 and restrains the coil housing 92 to the differential housing 37 to prevent axial movement of the coil housing 92 relative to the differential housing 37. In at least some embodiments, the portion 148 of the differential housing 37 radially outward of the groove 142 may have a reduced axial extent such that the outer surface 150 of the retainer 130 does not extend axially beyond the radially inner surface 152 of the groove 142 and the axial position of the bearing 88 is not affected by the retainer 130 when installed in the groove 142. Further, retainer 130 may be coupled to a bearing (e.g., bearing 88) or held in place by a bearing (e.g., bearing 88). For example, retainer 130 may be trapped between bearing 88 and a surface of housing 37, with or without any flange received in a groove (e.g., flange 138 and groove 142 would be optional in such an embodiment).

In at least some embodiments, the groove 142 is formed in a surface radially inward of the housing surface 79 along which the plunger 54 moves. In at least some embodiments, in use of differential 23, the area of housing 37 in which grooves 142 are formed is not under high stress, and thus the reduced thickness of housing 37 in this area does not compromise the durability of housing 37. Of course, other arrangements may be used as desired.

Retainer 130 may be made of any suitable material, including various metals and plastics, as well as composites. The retainer 130 may be lightweight and durable. Further, the single piece retainer 130 may engage circumferentially continuous portions of the coil housing 92 or discrete, spaced apart portions of the housing to securely retain the coil housing to the differential housing 37. The one-piece retainer 10 may be easier to handle and install than multiple clips having multiple fasteners. Although described above as annular, retainer 130 may be c-shaped with a slot or opening defining a free end of the retainer. In at least some embodiments, the retainer circumferentially spans more than 180 degrees, and in some embodiments, the retainer may span more than 300 degrees between the ends.

Further, retainer 130 may provide a stop surface that limits movement of plunger 54 (e.g., may define a first position of plunger 54). In some embodiments, an incomplete differential assembly that does not include bearings 88 may be transported from one location to another, and with the bearings out of place, the plunger 54 may be separated from the differential housing 37. Thus, in addition to, or instead of defining the first position of the plunger 54, the retainer 130 may retain the plunger 54 on the housing 37 until the bearing 88 or other plunger stop surface is provided.

Fig. 7-10 relate to a differential that may be constructed and arranged similar to differential 23 described above with respect to fig. 2-4, except as noted herein. For convenience in describing the embodiment, the same reference numerals will be used for the same components that have been described, and the above description is incorporated herein. In fig. 7-10, a retainer 160 is provided to inhibit or prevent axial movement of the coil 49 relative to the differential housing 37. In at least some embodiments, a first portion of the retainer 160 engages the differential housing and a second portion of the retainer 160 engages the coil housing 92.

In the illustrated embodiment, the retainer 160 is largely annular with a gap 162 between circumferentially spaced first and second ends 164, 166 of the retainer. Thus, the holder has a so-called "C-shape". In at least some embodiments, the retainer 160 spans more than 180 degrees circumferentially, and in some embodiments, the retainer may span more than 300 degrees such that the ends 164, 166 of the retainer 160 are spaced apart a distance less than the outer diameter of the portion of the housing 37 on which the retainer 160 is received.

Retainer 160 has an axial dimension between inward face 168 and outward face 170, and a radial dimension between outer surface 172 and inner surface 174. As shown in fig. 8-10, the outer surface 172 may have the same radius along the entire circumferential extent of the retainer, or be otherwise formed as desired. The inner surface 174 has a varying radius along the circumferential extent of the retainer 160, with a plurality of spaced apart and radially inwardly extending flanges 176 disposed along the circumferential extent of the retainer 160. So arranged, the body 178 of the retainer 160 has a first radial dimension, and in the region of the flange 176, the retainer 160 has a second, larger radial dimension. The cross-sectional view of fig. 9 is taken through flange 176, and the cross-sectional view of fig. 10 is taken through a portion of the body 178 of the retainer.

As shown in fig. 8, the differential case 37 has one or more axially extending skirts 180, the skirts 180 being radially outward of the coil case 92 and axially overlapping at least a portion of the coil case 92. A plurality of skirts 180 is shown in fig. 8, and the housing 37 will be described herein with reference to a plurality of skirts. The skirt 180 each includes a groove 182 in the radially outer surface, and in assembly, the retainer 160 is received in the groove 182. To receive the retainer flange 176, a gap 184176 may be provided between adjacent skirt portions 180

As shown in fig. 8. If one or more gaps 184 are not provided, suitably spaced openings aligned with the grooves 182 and extending through the skirt may be provided. In such an arrangement, the retainer 160 may need to be opened further to allow the retainer flange to pass through the outer surface of the skirt(s). In at least some embodiments, the inner surface 174 of the body 178 is radially smaller than the outer surface 186 of the skirt(s), and thus the retainer 160 must flex and open such that the inner surface 174 passes over and over the outer surface 186 of the skirt(s). Then, when retainer 160 is aligned with groove 182, the material of retainer 160 may resiliently return to its unbent state, wherein inner surface 174 is received in skirt 180 within groove 182 and radially overlapped by skirt 180. The groove 182 may have an axial dimension sized to receive the retainer 160 therein and limit axial movement of the retainer 160 relative to the differential housing 37.

To maintain the axial position of the coil housing 92 with the retainer 160 mounted on the skirt(s), the coil housing 92 includes radially extending and axially facing stop surfaces 188. As shown in fig. 9, the retainer flange 176 radially overlaps the stop surface 188 and is axially adjacent the stop surface 188. The portion of the coil housing 92 between the inboard end 124 and the stop surface 188 is trapped between the differential housing 37 and the inward face 168 of the retainer 160 (specifically, the inward face 168 of the retainer flange 176). In this way, axial movement of the coil housing 98 relative to the differential housing 37 is restricted or prevented. In the example shown, the stop surface 188 is a sidewall of a groove 190 provided in a radially outer surface 192 of the coil housing 92, wherein the groove 190 is wider than an axial dimension of the retainer 160 (e.g., an axial dimension of the retainer flange 176).

In at least some embodiments, the differential includes an annular plate 194, the annular plate 194 having inwardly extending projections 196, the projections 196 being received in the gaps 184 between the skirts 180. The tab 196 may be bolted to the clutch ring 56 to detect the position of the clutch ring 56 in response to movement of the plate 194 by a position sensing device. In this arrangement, the retainer flange 176 may be constructed and arranged to be received in the same gap 184 between the skirts 180 that have been provided for the plate 194. Further, the plate 194 and/or a portion of the housing 37 may have a larger outer diameter than the retainer 160, and the retainer 160 may be received between the axial ends of the differential housing 37 such that the retainer 160 does not increase the axial dimension of the differential 23.

Retainer 160 may be made of any suitable material, including various metals and plastics, as well as composites. The retainer 160 may be lightweight and durable. Further, the single piece retainer 160 may engage circumferentially continuous portions of the coil housing 92 or discrete, spaced apart portions of the housing 92 to securely retain the coil housing to the differential housing 37. The single piece retainer 160 may be easier to handle and install than multiple clips having multiple fasteners.

The retainers 100, 130, 160 avoid the need to provide space for components on the surface 79 along which the plunger 54 moves. This enables the surface 79 to be axially shorter if desired, and this distance/dimension may be added to one or both of the clutch ring 56 and the surface 198 (labeled in fig. 6) of the differential housing 37 that overlaps the side gear 34. Providing a thicker clutch ring 56 stiffens the clutch ring and enables the clutch ring to handle higher loads. Providing a longer contact surface between the differential case surface 198 and the side gears 34 reinforces the case 37 and enables the case to handle higher loads. In addition, the coil 49 may be made larger so as to be able to provide a more powerful driving force for the plunger 54. For example, the coil 49 may now extend the entire length of the surface 79 or more, wherein the components holding the coil are no longer located on the surface 79 and no longer interfere with such extension or expansion of the coil.

The additional strength of the housing 37 and/or clutch ring 56 and the ability to enlarge the size of the coil 49 are of commercial interest in at least some applications where a smaller size differential assembly is required in relatively high torque applications. Simply making the housing larger to provide space for higher loads is not acceptable, and making the housing smaller while still functioning may be difficult to achieve. Thus, the retainers described herein are a significant advance over previous components for retaining a solenoid coil on a differential housing.

Although the description above refers to a locking differential, other rotary power transmissions (e.g., a power take-off unit or an axle disconnect device) may utilize clutches having actuators as described herein. In this regard, the power transmission may include a plurality of rotating components, such as gears and/or shafts, wherein clutches and actuators are used to selectively couple at least two components together, for example, to alter the torque flow path through the device. Accordingly, the present disclosure relates more generally to actuators having the described retainers, and is not limited to a particular application. The forms of the application disclosed herein constitute presently preferred embodiments and many others are possible. It is not intended herein to mention all of the possible equivalents or derivatives of the application. It is to be understood that the terminology used herein is intended to be in the nature of words of description rather than of limitation, and that various changes may be made without departing from the spirit or scope of the application.

Unless explicitly indicated to the contrary herein, all terms used in the claims are intended to be given their broadest reasonable constructions and their ordinary meanings as understood by those skilled in the art. In particular, the use of the singular articles such as "a," "an," "the," etc. should be understood to recite one or more of the indicated elements unless a claim recites an explicit limitation to the contrary.

Claims (19)

1. A rotary power transmission device comprising:

a device housing having an interior in which a plurality of components are received for rotation;

a clutch received within the device housing and having a clutch ring selectively engageable with one of the plurality of components;

an actuator having a coil and a plunger driven to move along an axis and relative to the clutch; and

a retainer having a first portion engaging the device housing and a second portion radially overlapping the coil and limiting axial movement of the coil relative to the device housing.

2. The device of claim 1, wherein the coil comprises a coil housing and a wire coil within the coil housing, and wherein the first portion extends axially and is received on a portion of the device housing and the second portion extends from a sidewall and overlaps a portion of the coil housing.

3. The device of claim 2, wherein the first portion of the retainer is press-fit onto an outer surface of the device housing.

4. The device of claim 2, wherein the first portion extends axially and the second portion extends radially from the sidewall.

5. The device of claim 2, wherein the coil housing has an inboard end adjacent the device housing and the coil housing has an outboard end opposite and axially spaced from the inboard end, and wherein the retainer overlaps a portion of the coil housing between the inboard end and the outboard end and does not extend axially beyond the outboard end.

6. The device of claim 5, wherein the coil housing includes a flange extending radially outward and between the inboard end and the outboard end, the flange including a first face received against the device housing, and the flange including a second face engaged by the second portion of the retainer.

7. The device of claim 1, wherein the coil has a coil housing and a wire coil within the coil housing, and wherein the first portion of the retainer comprises a flange coupled to the device housing, and the second portion of the retainer comprises a sidewall extending from the flange and overlapping a portion of the coil housing.

8. The device of claim 7, wherein the device housing includes a groove, and wherein the flange is press-fit into the groove with a friction fit between one surface of the flange and a surface defining the groove.

9. The device of claim 8, wherein the plunger slides along an annular surface of the device housing when the plunger is driven for movement, and the groove is formed to be spaced radially inward from the annular surface.

10. The device of claim 8, wherein the flange extends axially into a groove, and the flange has a radially inner surface and an opposite radially outer surface, wherein at least one of the radially inner surface and the radially outer surface frictionally engages the device housing within the groove.

11. The device of claim 1, wherein the coil has a coil housing and a wire coil within the coil housing, and wherein the retainer includes a plurality of inwardly extending flanges defining the second portion of the retainer, wherein each flange radially overlaps the coil housing and circumscribes a portion of the coil housing between the flange and the device housing.

12. The device of claim 11, wherein the first portion of the retainer is defined by a body, the flange extending radially inward from the body.

13. The device of claim 12, wherein the device housing includes a groove opening into a radially outer surface of the device housing and extending radially into the device housing, and wherein the body is received within the groove.

14. The device of claim 13, wherein the coil housing is located within the device housing radially inward of the recess, and the flange extends inwardly from the body and radially overlaps a portion of the coil housing.

15. The device of claim 14, wherein the device housing includes a plurality of circumferentially spaced apart skirts, and wherein the groove is formed in the plurality of skirts and the flange is received circumferentially between adjacent skirts.

16. The device of claim 13, wherein the body includes a first end and a second end circumferentially spaced apart from the first end, a gap between the first end and the second end.

17. A rotary power transmission device comprising:

a device housing having an interior in which a plurality of components are received for rotation;

a clutch ring received within the device housing and selectively engageable with one of the plurality of components;

an actuator having a coil housing, a coil within the coil housing, and a plunger driven to move along an axis and relative to the clutch ring to move the clutch ring relative to the device housing; and

a retainer having a first portion engaging the device housing and a second portion extending radially from the first portion toward the axis, wherein the second portion radially overlaps the coil housing and limits axial movement of the coil housing relative to the device housing.

18. The device of claim 17, wherein the first portion extends axially and engages a portion of the device housing.

19. The device of claim 17, wherein the first portion is received within a recess in the device housing.