Centrifugal pendulum absorber

A centrifugal pendulum absorber includes: a center plate arranged to receive a torque; a first pendulum connected to the center plate; and a second pendulum mass connected to the center plate and circumferentially aligned with the first pendulum mass. The first pendulum mass includes a first circumferential end and a first curved portion disposed at the first circumferential end. The second pendulum mass includes a second circumferential end disposed proximate to the first circumferential end and a second curved portion disposed at the second circumferential end. The first curved portion and the second curved portion are each convex relative to a first circumferential direction from the first circumferential end to the second circumferential end.

TECHNICAL FIELD

The present disclosure relates generally to a centrifugal pendulum absorber, and more specifically to a pendulum mass of a centrifugal pendulum absorber.

BACKGROUND

A known centrifugal pendulum absorber includes resilient bumpers to soften contact between pendulum masses as the masses displace in reaction to rotation of the absorber. However, the absorber may be unable to prevent contact between the pendulum masses in cases of asynchronous movement between the pendulum masses. It is desirable to have alternative designs and configurations to reduce stress on the pendulum masses caused by impact loading during asynchronous movement between the pendulum masses.

SUMMARY

Embodiments of this disclosure provide a centrifugal pendulum absorber including a center plate arranged to receive a torque, a first pendulum connected to the center plate, a second pendulum mass connected to the center plate and circumferentially aligned with the first pendulum mass. The first pendulum mass includes a first circumferential end and a first curved portion disposed at the first circumferential end. The second pendulum mass includes a second circumferential end disposed proximate to the first circumferential end and a second curved portion disposed at the second circumferential end. The first curved portion and the second curved portion are each convex relative to a first circumferential direction from the first circumferential end to the second circumferential end

In embodiments, the first pendulum mass and the second pendulum mass may be disposed on a same axial side of the center plate. In embodiments, the second curved portion may be configured to be received within the first curved portion during asynchronous movement between the first pendulum mass and the second pendulum mass. In embodiments, a radius of curvature of the first curved portion may be greater than a radius of curvature of the second curved portion.

In embodiments, the first pendulum mass may include a first outer portion extending radially outward from the first curved portion, and the second pendulum mass may include a second outer portion extending radially outward from the second curved portion. The second outer portion and the first outer portion may extend obliquely relative to each other. In embodiments, the first curved portion may be disposed radially outside of the center plate, and the second curved portion may be disposed radially outside of the center plate.

In embodiments, the first curved portion may extend from a radially outer end to a radially inner end. The radially inner end may be disposed radially outside of the center plate. The second curved portion may extend from a radially outer end to a radially inner end. The radially inner end of the second curved portion may be circumferentially aligned with the radially inner end of the first curved portion. The radially outer end of the second curved portion may be circumferentially aligned with the radially outer end of the first curved portion. The centrifugal pendulum absorber may include a fastener disposed proximate to the second end and radially between the radially outer end and the radially inner end of the second curved portion. The fastener may be configured to fixedly connect the second pendulum mass to a further pendulum mass axially aligned with the second pendulum mass. The centrifugal pendulum absorber may include a fastener disposed proximate to the first end and radially between the radially outer end and the radially inner end of the first curved portion. The fastener may be configured to fixedly connect the first pendulum mass to a further pendulum mass axially aligned with the first pendulum mass.

In embodiments, the first curved portion may be disposed proximate to the second curved portion. In embodiments, the first curved portion may include an apex spaced from the first circumferential end in a second, opposite circumferential direction. In embodiments, the second curved portion may include an apex spaced from the second circumferential end in the first circumferential direction.

Embodiments of this disclosure further provide a pendulum mass for a centrifugal pendulum absorber including a first circumferential end and a second circumferential end spaced from the first circumferential end. The pendulum mass further includes a first curved portion disposed at the first circumferential end. The pendulum mass further includes a second curved portion disposed at the second circumferential end. The first curved portion and the second curved portion are each convex relative to a first circumferential direction from the second circumferential end to the first circumferential end.

In embodiments, a radius of curvature of the first curved portion may be greater than a radius of curvature of the second curved portion. In embodiments, the pendulum mass may include a first outer portion extending radially outward from the first curved portion. The pendulum mass may further include a second outer portion extending radially outward from the second curved portion. The second outer portion and the first outer portion may extend obliquely relative to each other.

In embodiments, pendulum mass may include a first hole disposed proximate to the first circumferential end and circumferentially aligned with the first curved portion. The first hole may be configured to receive a fastener for fixedly connecting the pendulum mass to a further pendulum mass axially aligned with the pendulum mass. The pendulum mass may include a second hole disposed proximate to the second circumferential end and circumferentially aligned with the second curved portion. The second hole may be configured to receive a further fastener for fixedly connecting the pendulum mass to the further pendulum mass.

In embodiments, the first curved portion may be circumferentially aligned with the second curved portion.

DETAILED DESCRIPTION

Embodiments of the present disclosure are described herein. It should be appreciated that like drawing numbers appearing in different drawing views identify identical, or functionally similar, structural elements. Also, it is to be understood that the disclosed embodiments are merely examples and other embodiments can take various and alternative forms. The figures are not necessarily to scale; some features could be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the embodiments. As those of ordinary skill in the art will understand, various features illustrated and described with reference to any one of the figures can be combined with features illustrated in one or more other figures to produce embodiments that are not explicitly illustrated or described. The combinations of features illustrated provide representative embodiments for typical applications. Various combinations and modifications of the features consistent with the teachings of this disclosure, however, could be desired for particular applications or implementations.

The terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the following example methods, devices, and materials are now described.

A centrifugal pendulum absorber typically includes a first pendulum mass and a second pendulum mass circumferentially aligned with each other. Specifically, a circumferential end of the first pendulum mass may be proximate a circumferential end of the second pendulum mass, e.g., a line extending along a circumference about a central axis may pass through the circumferential end of the first pendulum mass, a gap disposed circumferentially between the pendulum masses, and then through the circumferential end of the second pendulum mass. In some centrifugal pendulum absorber arrangements, each of the first and second pendulum masses may include a curved portion disposed at the respective circumferential ends. Each curved portion may be convex relative to the gap, i.e., the curved portions may be curved in opposite directions relative to each other. In such arrangements, apexes of the curved portions may impact each other during asynchronous movement of the pendulum masses, which can increase a likelihood of damage to the pendulum masses.

Advantageously, embodiments described herein provide a centrifugal pendulum absorber that includes a center plate, a first pendulum mass connected to the center plate, and a second pendulum mass connected to the center plate and circumferentially aligned with the first pendulum mass. The pendulum masses each include respective circumferential ends disposed proximate to each other and respective curved portions disposed at the corresponding circumferential end. Each curved portion is convex relative to a first circumferential direction. Embodiments according to the present disclosure provide several advantages including increasing clearance between circumferentially adjacent pendulum masses, which can reduce a likelihood of the circumferentially adjacent pendulum masses impacting each other. Additionally, curving the curved portions on the proximate circumferential ends of circumferentially adjacent pendulum masses in a same direction can increase an effective contact area between the curved portions during an impact event, which can reduce impact stresses on the circumferentially adjacent pendulum masses. Thus, the durability and service life of pendulum masses are increased, contributing to an increase in the durability and service life of centrifugal pendulum absorber.

Referring toFIGS.1-3, a centrifugal pendulum absorber100is generally shown. At least some portions of the centrifugal pendulum absorber100are rotatable about an axis A. Words such as “axial,” “radial,” “circumferential,” “outward,” etc. as used herein are intended to be with respect to the axis A unless stated otherwise. The centrifugal pendulum absorber100includes: a center plate102; pairs104of pendulum masses106,108; and resilient bumpers110connected to masses106,108.

The center plate102is arranged to receive a torque. The center plate102includes: a side112facing in an axial direction AD1parallel to the axis A; and a side114facing in an axial direction AD2, opposite direction AD1. The pendulum masses106are disposed on the side112and the pendulum masses108are disposed on the side114. That is, the pairs104axially bracket center plate102. The center plate102may be a component of a vibration damper and include windows (not numbered) arranged to receive springs (not numbered).

The center plate102includes openings116. Each mass106includes openings118. Each mass108includes openings120. The centrifugal pendulum absorber100includes rollers122. Each roller122passes through a respective opening116and terminates in a respective opening118and a respective opening120.

The centrifugal pendulum absorber100includes fasteners124non-rotatably connecting pairs104of masses106,108. Each resilient bumper110is installed and disposed around a respective fastener124. Each resilient bumper110is rotatable about the respective fastener124. That is, the resilient bumpers110are rotatable relative to the center plate102. The resilient bumpers110are configured to reduce a likelihood of direct contact of the masses106,108due to the displacement of the circumferentially adjacent pairs104toward each other.

Each mass106,108extends partially circumferentially about the central axis A from a first circumferential end CE1to a second circumferential end CE2. The masses106,108are circumferentially aligned with each other such that the first circumferential end CE1of one mass106,108is disposed proximate to the second circumferential end CE2of another, circumferentially adjacent mass106,108.

Each pair104includes two resilient bumpers110. One of the two resilient bumpers110is located proximate to the first circumferential ends CE1of the masses106,108in the pair104and extends past the pair104in a first circumferential direction CD1. The other of the two resilient bumpers110is located proximate to the second circumferential ends CE2of the masses106,108in the pair104and extends past the pair104in a second circumferential direction CD2, opposite the first circumferential direction CD1.

Each mass106,108may include an inner surface126and an outer surface128disposed radially outside of the inner surface126. Each inner surface126may extend from the first circumferential end CE1of the respective mass106,108to the second circumferential end CE2of the respective mass106,108. Each outer surface128may extend from the first circumferential end CE1of the respective mass106,108to the second circumferential end CE2of the respective mass106,108.

Referring toFIG.4, each mass106,108includes a first curved portion130disposed at the first circumferential end CE1. Each first curved portion130may be disposed radially outside of the center plate102. Each first curved portion130may include a radially inner end132and a radially outer end134disposed radially outside of the radially inner end132. Each radially inner end132may be disposed radially outside of the corresponding inner surface126of the respective mass106,108. Each radially outer134end may be disposed radially inside of the corresponding outer surface128of the respective mass106,108.

Each first curved portion130is convex relative to a line L extending through the respective mass106,108, e.g., the circumferential ends CE1, CE2thereof, in the first circumferential direction CD1. That is, each first curved portion130is curved about a respective center spaced from the corresponding first circumferential end CE1of the respective mass106,108in the first circumferential direction CD1. Said differently, each first curved portion130includes an apex136spaced from the corresponding radially inner and radially outer ends132,134of the respective first curved portion130in the second circumferential direction CD2.

Each mass106,108may further include a first outer portion138disposed at the first circumferential end CE1. Each first outer portion138may extend radially inward from the corresponding outer surface128of the respective mass106,108to the corresponding first curved portion130, e.g., the radially outer end134thereof, of the respective mass106,108. Each first outer portion138may, for example, extend in the first circumferential direction CD1to the corresponding first curved portion130. That is, each radially outer end134of the corresponding first curved portions130may be spaced from the corresponding outer surface128of the respective mass106,108in the first circumferential direction CD1.

Each mass106,108may further include a first inner portion140disposed at the first circumferential end CE1. Each first inner portion140may extend radially outward from the corresponding inner surface126of the respective mass106,108to the corresponding first curved portion130, e.g., the radially inner end132thereof, of the respective mass106,108. Each first inner portion140may, for example, extend in the first circumferential direction CD1to the corresponding first curved portion130. That is, each radially inner end132of the corresponding first curved portions130may be spaced from the corresponding inner surface126of the respective mass106,108in the first circumferential direction CD1.

Each first inner portion140may include a curved segment (not numbered) extending from the corresponding inner surface126towards the corresponding first curved portion130of the respective mass106,108. For example, each first inner portion140may be convex relative to a line (not shown) extending through the respective first inner portion140in the first circumferential direction CD1. As one example, the curved segment of the first inner portion140may extend to the first curved portion130. As another example, the first inner portion140may include a radial segment (not numbered) extending radially inward from the first curved portion130to the curved segment.

Each mass106,108may further include a first hole142disposed proximate to the first circumferential end CE1. The first hole142on one mass106in a pair104is axially aligned with the first hole142on the other mass108in the pair104. The first holes142are configured to receive the fasteners124. Each first hole142may be, at least partially, circumferentially aligned with the corresponding first curved portion130of the respective mass106,108. That is, the line L may pass through, in order, the first hole142, e.g., a portion thereof, and the first curved portion130. For example, each first hole142may be disposed radially between the radially inner end132and the radially outer end134of the corresponding first curved portion130of the respective mass106,108.

Referring toFIG.5, each mass106,108includes a second curved portion144disposed at the second circumferential end CE2. Each second curved portion144may be disposed radially outside of the center plate102. Each second curved portion144may include a radially inner end146and a radially outer end148disposed radially outside of the radially inner end146. Each radially inner end146may be disposed radially outside of the corresponding inner surface126of the respective mass106,108. Each radially outer end148may be disposed radially inside of the corresponding outer surface128of the respective mass106,108.

Each second curved portion144is convex relative to the line L. That is, each second curved portion144is curved about a respective center spaced from the corresponding second circumferential end CE2of the respective mass106,108in the first circumferential direction CD1. Said differently, each second curved portion144includes an apex150spaced from the corresponding radially inner and radially outer ends146,148of the respective second curved portion144in the second circumferential direction CD2.

Each mass106,108may further include a second outer portion152disposed at the second circumferential end CE2. Each second outer portion152may extend radially inward from the corresponding outer surface128of the respective mass106,108to the corresponding second curved portion144, e.g., the radially outer end148thereof, of the respective mass106,108. As one example, each second outer portion152may extend obliquely relative to the corresponding first outer portion138of the respective mass106,108. For example, each second outer portion152may extend radially inward to the corresponding second curved portion144such that each radially outer end148of the corresponding second curved portions144may be radially aligned with an end of the corresponding outer surface128of the respective mass106,108.

Each mass106,108may further include a second inner portion154disposed at the second circumferential end CE2. Each second inner portion154may extend radially outward from the corresponding inner surface126of the respective mass106,108to the corresponding second curved portion144, e.g., the radially inner end146thereof, of the respective mass106,108. Each second inner portion154may, for example, extend in the second circumferential direction CD2to the corresponding second curved portion144. That is, each radially inner end146of the corresponding second curved portions144may be spaced from the corresponding inner surface126of the respective mass106,108in the second circumferential direction CD2.

Each second inner portion154may include a curved segment (not numbered) extending from the corresponding inner surface126towards the corresponding second curved portion144of the respective mass106,108. For example, each second inner portion154may be convex relative to a line (not shown) extending through the respective second inner portion154in the second circumferential direction CD2. As one example, the curved segment of the second inner portion154may extend to the second curved portion144. As another example, the second inner portion154may include a radial segment (not numbered) extending radially inward from the second curved portion144to the curved segment.

Each mass106,108may further include a second hole156disposed proximate to the second circumferential end CE2, as shown inFIG.6. The second hole156on one mass106in a pair104is axially aligned with the second hole156on the other mass108in the pair104. The second holes156are configured to receive the fasteners124. Each second hole156may be, at least partially, circumferentially aligned with the second curved portion144. For example, each second hole156may be disposed radially between the radially inner end146and the radially outer end148of the corresponding second curved portion144of the respective mass106,108.

Referring toFIG.6, each first curved portion130may be configured to receive the corresponding second curved portion144of a circumferentially adjacent mass106,108. For example, the radially inner end132of each first curved portion130may be circumferentially aligned with the radially inner end146of the corresponding second curved portion144of the circumferentially adjacent mass106,108. Additionally, or alternatively, the radially outer end132of each first curved portion130may be circumferentially aligned with the radially outer end148of the corresponding second curved portion144of the circumferentially adjacent mass106,108.

A radius of curvature R of the first curved portion130may be greater than a radius of curvature R of the second curved portion144. Providing the first curved portion130with a larger radius of curvature than the second curved portion144permits the apex150of the second curved portion144to be circumferentially displaced between the radially inner and outer ends132,134of the first curved portion130, which can increase clearance between each first curved portion130and the corresponding second curved portion144on the circumferentially adjacent mass106,108.

FIG.6is applicable to a condition in which pairs104are subject to asynchronous movement therebetween. In reaction to rotation of the center plate102, the configuration of the rollers122in the openings116,118, and120, enables radial and circumferential displacement of the masses106,108, with respect to the center plate102, to absorb vibration associated with the rotation of the center plate102. At times, the radial and circumferential displacement causes asynchronous movements between circumferentially adjacent pairs104of masses106,108, i.e., the circumferentially adjacent pairs104of masses106,108displace toward each other. In such an example, the first curved portions130of masses106A,108A may receive the corresponding second curved portions144of masses106B,108B. That is, each apex150of the corresponding second curved portions144may be displaced circumferentially between the corresponding radially inner and outer ends132,134of the respective first curved portion130. In the discussion above and in the discussion that follows, capital letters are used to designate a specific component from a group of components otherwise designated by a three-digit number, for example, mass106A is a specific example from among masses106.

In some situations, the resilient bumpers110may be unable to absorb impact forces between the pairs104of masses106,108. In these situations, each second curved portion144may contact the corresponding first curved portion130for the circumferentially adjacent mass106,108, as shown inFIG.6. In such an example, a contact area between each second curved portion144and the corresponding first curved portion130corresponds to an arc of the respective second curved portion144that has a same radius of curvature as an arc of the respective first curved portion130.

By providing, on proximate circumferential ends of circumferentially adjacent pendulum masses, curved portions that are each curved in a same direction relative to each other, the embodiments disclosed herein can increase a contact area between the circumferentially adjacent pendulum masses. For example, the contact area may be defined by corresponding arcs of the curved portions having similar radii of curvature as opposed to the apexes of the curved portions. This increase in the contact area can decrease stress from an impact between the curved portions caused by asynchronous movement between circumferentially adjacent pendulum masses. Additionally, the curved portions according to the exemplary embodiments disclosed herein can increase a clearance between the proximate circumferential ends of the circumferentially adjacent pendulum masses, which can decrease a likelihood of the circumferentially adjacent pendulum masses impact each other during asynchronous movement between the pendulum masses.