Patent Description:
The invention can be applied in heavy duty vehicles, such as trucks, buses, recreational vehicles and construction equipment.

A wheel hub assembly, also sometimes referred to as a hub assembly, wheel hub unit or wheel hub bearing, is an automotive part used in many vehicle types such as trucks and semi-trailers. A wheel is attached to the wheel hub assembly by bolts. A roller bearing between the axle hub and axle shaft ensures easy rotation of the wheels.

The wheel hub assembly comprises a hub lock nut, which is a safety component that retains the wheel end in its position. It is important that the hub lock nut is properly tightened such that the wheel does not detach from the wheel hub assembly. The hub lock nut must also provide a prevailing torque to prevent loosening of the hub lock nut which holds the wheel hub in position.

<CIT> discloses a locknut assembly comprising a lock nut configured to be mated with a compression washer in a mated position.

<CIT> discloses a locknut assembly comprising a nut arranged to be mated with a tapered washer.

There is a need for improved hub lock nut assemblies.

It is an object of the present disclosure to provide improved hub lock nut assemblies.

The invention is a hub lock nut as described in claim <NUM>.

This object is obtained by a hub lock nut assembly for retaining a vehicle wheel hub in position. The hub lock nut assembly comprises a hub lock nut and a mating component with which the hub lock nut is arranged to be mated in a mated position. The hub lock nut comprises a circumferential inner wall defining a central hole. This inner wall has a threaded portion separated into a first section and a second section by an annular groove in the threaded portion, thereby configuring the second section as a resilient portion arranged to flex with respect to the first section in an axial direction. The mating component comprises an inner wall defining a central hole extending in the axial direction and matching the central hole of the hub lock nut. The mating component comprises an annular end surface facing in the axial direction, wherein a protrusion is arranged on the annular end surface adjacent to the central hole. The protrusion is configured to exert a force F on the second section of the hub lock nut threaded portion, in the axial direction, when in the mated position, thereby retaining the vehicle wheel hub in position.

This hub lock nut assembly provides a robust prevailing torque function and enables an efficient wheel hub assembly process. The prevailing torque function is provided by the hub lock nut and the safety washer, and does not require modifications to the spindle, which is an advantage. The hub lock nut can be manufactured in a cost efficient manner by simply machining the groove into existing nuts of suitable dimension.

According to aspects, a width of the second section of the hub lock nut threaded portion in the axial direction corresponds to between two and three times a pitch or lead of the threaded portion. This range of widths provides a desired resilience property of the resilient portion. The width is large enough such that the resilient portion is robust, yet flexible enough to act as resilient portion.

According to the invention, a width of the annular groove in the axial direction is between <NUM> and <NUM> times a pitch or lead of the threaded portion, and preferably <NUM> times the pitch or lead of the threaded portion. This range of widths allows the second section of the hub lock nut threaded portion to flex sufficiently, while not weakening the threaded portion too much. According to aspects, a depth of the annular groove is between <NUM> and <NUM>. This range of depths provide the required resilience property of the second portion.

According to aspects, the protrusion extends annually around the whole annular end surface of the mating component. This means that the pressure exerted by the mating component is evenly distributed around the whole hub lock nut, which is an advantage. According to aspects, the external force is configured to provide a prevailing torque of the hub lock nut assembly in dependence of the hub lock nut dimension, wherein the prevailing torque varies between <NUM> and <NUM>. It is an advantage that the prevailing torque can be configured in dependence of hub lock nut dimension, since different dimensions of locking nuts often require different prevailing torque values.

According to aspects, any of the hub lock nut and/or the mating component is integrally formed by hot-formed steel. Thus, advantageously, the disclosed hub lock nuts and mating components can be manufactured in a cost efficient manner.

There are also disclosed herein hub lock nuts, safety washers, spindles, wheel hubs and vehicles associated with the above-mentioned advantages.

The skilled person realizes that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention, which is defined by the appended claims.

<FIG> schematically illustrates a vehicle <NUM> with vehicle wheel hubs <NUM> holding the wheels of the vehicle in position.

<FIG> schematically illustrates one such wheel hub assembly <NUM>. A hub lock nut <NUM> is used to secure the vehicle wheel hub <NUM> to the spindle <NUM>. Often, a safety washer <NUM> is arranged between the hub lock nut <NUM> and the wheel hub <NUM>. It is desired to lock the wheel hub in position by using a hub lock nut assembly configured to provide a prevailing torque according to some given specification. Wheel hubs such as the wheel hub <NUM> schematically illustrated in <FIG> are known in general and will therefore not be discussed in detail here.

The present disclosure relates to a hub lock assembly adapted to provide a required prevailing torque. Prevailing torque differentiates a locknut from a free spinning nut based on a value of how much torque is required during installation before clamp loading. For example, on a nylon-insert nut, it is the torque needed to overcome the resistance of the nylon dragging across the mating thread. This torque value is usually not very high relative to final installation torque. Tolerance ranges for torque are specified in some standards such as ISO, DIN, IFI, ASME, SAE, AN-, MS-, NAS- NASM-.

Herein, lead is the distance along a screw's or bolt's axis that is covered by one complete rotation of the screw or bolt. Pitch is the distance from the crest of one thread to the next. Because the vast majority of screw threadforms are single-start threadforms, their lead and pitch are the same. Single-start means that there is only one "ridge" wrapped around the cylinder of the screw's body. Each time that the screw's body rotates one turn, it has advanced axially by the width of one ridge. "Double-start" means that there are two "ridges" wrapped around the cylinder of the screw's body. Each time that the screw's body rotates one turn, it has advanced axially by the width of two ridges. Another way to express this is that lead and pitch are parametrically related, and the parameter that relates them, the number of starts, very often has a value of <NUM>, in which case their relationship becomes equality. In general, lead is equal to pitch times the number of starts. Herein, without loss of generality, single-start threads are assumed throughout.

Whereas metric threads are usually defined by their pitch, that is, how much distance per thread, inch-based standards usually use the reverse logic, that is, how many threads occur per a given distance. Thus, inch-based threads are defined in terms of threads per inch (TPI). Pitch and TPI describe the same underlying physical property-merely in different terms.

The present disclosure builds on a type of hub lock nut which has a groove machined into the threaded portion. This groove divides the threaded portion into two parts. The part closest to the wheel hub is made relatively narrow so as to form a resilient portion able to flex axially when subject to a pressure force. When this resilient portion flexes, friction increases between the threads on the narrow portion and the corresponding threads on the spindle. This increased friction provides a prevailing toque function in a convenient and cost effective manner.

<FIG> shows an example hub lock nut <NUM> according to the present disclosure. The hub lock nut <NUM> comprises a circumferential inner wall <NUM> defining a central hole <NUM>. The inner wall <NUM> has a threaded portion <NUM> separated into a first section 310a and a second section 310b by an annular groove <NUM> in the threaded portion <NUM>, thereby configuring the second section 310b as a resilient portion arranged to flex with respect to the first section 310a in an axial direction A, as discussed above. The hub lock nut <NUM> is arranged to be threaded onto the spindle and held in position by the prevailing torque.

<FIG> shows an example mating component <NUM> according to the present disclosure. The mating component <NUM> is here a safety washer comprising an inner wall <NUM> defining a central hole <NUM> extending in the axial direction A and corresponding to the central hole <NUM> of the hub lock nut <NUM>. The mating component <NUM> comprises an annular end surface <NUM> facing in the axial direction A. A protrusion <NUM> is arranged on the annular end surface <NUM> close to the central hole <NUM>. This protrusion <NUM> is configured to exert a force F on the second section 310b of the hub lock nut <NUM> threaded portion <NUM>, in the axial direction A, when in the mated position, thereby retaining the vehicle wheel hub <NUM> in position.

<FIG> schematically illustrates the hub lock nut <NUM> and the mating component <NUM> in or close to the mating position, i.e., when the prevailing force is generated or is just about to be generated. The protrusion <NUM> on the mating component <NUM> is here shown to push against the side of the hub lock nut <NUM>. This push forces the second section of the threaded portion to flex inwards axially by the force F. The inwards flexing squeezes the groove <NUM> as the hub lock nut <NUM> is threaded onto the spindle <NUM>.

<FIG> schematically illustrates the effects of applying pressure axially to the second section 310b of the threaded portion <NUM>. The squeezing applies pressure between the threads of the second section 310b and the corresponding threads of the spindle 610b. This generates friction which in turn provides the required prevailing torque.

The hub lock nut and the safety washer may advantageously be manufactured using hot-formed steel.

To summarize, with reference to <FIG>, there is disclosed herein a hub lock nut assembly <NUM>, <NUM>, <NUM>, <NUM> for retaining a vehicle wheel hub <NUM> in position. The hub lock nut assembly comprises a hub lock nut <NUM> and a mating component <NUM> with which the hub lock nut <NUM> is arranged to be mated in a mated position. The hub lock nut <NUM> comprises a circumferential inner wall <NUM> defining a central hole <NUM>. Notably, the inner wall <NUM> has a threaded portion <NUM> separated into a first section 310a and a second section 310b by an annular groove <NUM> in the threaded portion <NUM>, thereby configuring the second section 310b as a resilient portion arranged to flex with respect to the first section 310a in an axial direction A. In other words, the inner wall <NUM> has a threaded portion <NUM> separated into a first section 310a and a second section 310b by an annular groove <NUM> in the threaded portion <NUM>, such that the second section 310b is a resilient portion arranged to flex with respect to the first section 310a in an axial direction A.

The mating component <NUM> comprises an inner wall <NUM> defining a central hole <NUM> extending in the axial direction A corresponding to the central hole <NUM> of the hub lock nut <NUM>. The mating component <NUM> also comprises an annular end surface <NUM> facing in the axial direction A, wherein a protrusion <NUM> is arranged on the annular end surface <NUM> adjacent to the central hole <NUM>. This protrusion <NUM> is configured to exert a force F on the second section 310b of the hub lock nut <NUM> threaded portion <NUM>, in the axial direction A, when in the mated position, thereby retaining the vehicle wheel hub <NUM> in position. The location of the protrusion should preferably be optimized such that it contacts the hub lock nut close to the central hole <NUM>.

According to aspects, a wheel hub safety washer constitutes the mating component <NUM>.

According to aspects, any of the hub lock nut or the safety washer is formed in hot-formed steel.

Certain ranges of dimensions have been found suitable for providing required values of prevailing torque on a heavy duty vehicle. According to some aspects, the external force F is configured to provide a prevailing torque of the hub lock nut assembly in dependence of the hub lock nut dimension, wherein the prevailing torque varies between <NUM> and <NUM>.

The skilled person may arrive at suitable dimensions for a given requirement on prevailing torque by simulation of basic experimentation, However, with reference to <FIG>;.

According to aspects, a width W2 of the second section 310b of the hub lock nut <NUM> threaded portion <NUM> in the axial direction A corresponds to between two and three times a pitch or lead of the threaded portion.

According to aspects, a width W of the annular groove <NUM> in the axial direction A is between <NUM> and <NUM> times a pitch or lead of the threaded portion <NUM>, and preferably <NUM> times the pitch or lead of the threaded portion <NUM>.

According to aspects, a depth D of the annular groove <NUM> is between <NUM> and <NUM>.

According to aspects, the protrusion <NUM> extends annually around the whole annular end surface <NUM> of the mating component <NUM>.

According to aspects, the protrusion <NUM> has a rounded cross-section shape or a rectangular cross-section shape.

According to aspects, any of the hub lock nut <NUM> and the mating component <NUM> is integrally formed by hot-formed steel.

It is appreciated that the different parts of the hub lock nut assemblies are also disclosed herein separately. Thus, there is disclosed herein a hub lock nut <NUM> for retaining a vehicle wheel hub <NUM> in position, the hub lock nut <NUM> being arranged to be mated with a mating component <NUM> in a mated position. The hub lock nut <NUM> comprises a circumferential inner wall <NUM> defining a central hole <NUM>. Notably, the inner wall <NUM> has a threaded portion <NUM> separated into a first section 310a and a second section 310b by an annular groove <NUM> in the threaded portion <NUM>, thereby configuring the second section 310b as a resilient portion arranged to flex with respect to the first section 310a in an axial direction A.

This hub lock nut may, according to aspects, have the dimensions discussed above in connection to <FIG>.

Claim 1:
A hub lock nut assembly (<NUM>, <NUM>, <NUM>, <NUM>) for retaining a vehicle wheel hub (<NUM>) in position, the hub lock nut assembly (<NUM>, <NUM>, <NUM>, <NUM>) comprising a hub lock nut (<NUM>) and a mating component (<NUM>) with which the hub lock nut (<NUM>) is arranged to be mated in a mated position,
the hub lock nut (<NUM>) comprising a circumferential inner wall (<NUM>) defining a central hole (<NUM>), wherein the inner wall (<NUM>) has a threaded portion (<NUM>) separated into a first section (310a) and a second section (310b) by an annular groove (<NUM>) in the threaded portion (<NUM>), thereby configuring the second section (310b) as a resilient portion arranged to flex with respect to the first section (310a) in an axial direction (A),
the mating component (<NUM>) comprising an inner wall (<NUM>) defining a central hole (<NUM>) extending in the axial direction (A) and corresponding to the central hole (<NUM>) of the hub lock nut (<NUM>), the mating component (<NUM>) comprising an annular end surface (<NUM>) facing in the axial direction (A), wherein a protrusion (<NUM>) is arranged on the annular end surface (<NUM>), the protrusion (<NUM>) being configured to exert a force (F) on the second section (310b) of the hub lock nut (<NUM>) threaded portion (<NUM>), in the axial direction (A), when in the mated position, thereby retaining the vehicle wheel hub (<NUM>) in position,
characterized by that a width (W) of the annular groove (<NUM>) in the axial direction (A) is between <NUM> and <NUM> times a pitch or lead of the threaded portion (<NUM>), and preferably <NUM> times the pitch or lead of the threaded portion (<NUM>).