Patent Description:
Motorized training involves many benefits for training both in sports and rehabilitation. Motorized training may generally be defined as the utilization of an electric machine to provide controllable resistance or assistance.

Motorized training equipment allows coaches, trainers, and rehab professionals to apply and control resistance across a broad range of foundational exercises and functional movements.

<CIT> discloses an exercise motion control device for an exercising apparatus, the exercise motion control device comprising: a stationary part, a rotary part with a circumferential magnet interface, wherein the magnet interface comprises a magnet receiving pattern that is shaped to receive a plurality of magnets and the rotary part comprises a motion control interface that is adapted to control an exercise motion.

Even though there exist apparatuses and equipment that fulfil their intended purposes, there is still room for optimisations in for example performance, weight, durability, as well as efficiency in manufacture and costs.

According to a one aspect of the present disclosure, there is provided an exercise motion control device for an exercising apparatus. The exercise motion control device comprises a stationary part and a rotary part with a circumferential magnet interface. The circumferential magnet interface comprises a magnet receiving pattern that is shaped to receive a plurality of magnets. The rotary part comprises a motion control interface that is adapted to control an exercise motion. The plurality of magnets is arranged in a Halbach array.

Such a solution may involve advantages in assembly, as the magnets may be received in the magnet receiving pattern. The magnets may thereby be properly positioned. The magnet receiving pattern may further make possible or facilitate providing a rotary part that does not require any back iron. In other words, the exercise motion control device may be back iron free. The present rotary part may be iron free. A back iron is a separate component, made of iron, traditionally arranged around magnets in a rotor or rotary part to control magnetic flux. The present rotary part, and consequently the exercise motion control device, may be back iron free and thus comparably light-weight. A light-weight rotary part may involve a low moment of inertia which may be beneficial for example in an exercising apparatus. A light-weight rotary part may facilitate fine-tuning a force velocity profile. Further, the rotary part may be corrosion resistant or even corrosion proof.

The exercise motion that the exercise motion control device controls is typically a motion associated with a movement of a person that performs muscular exercises. The exercising apparatus may thus typically be located in a gym or on a sports field such as a running track.

By the motion control interface being adapted to control an exercise motion may be meant that the rotary part, via the motion control interface, is connected to the motion that is associated with a movement of a person that exercises. For example, the motion control interface may be connected to a cable that in turn is connected to the person that exercises, or to an exercise handle pulled by the person. Alternatively, the motion control interface may be connected to a gearing that in turn is connected to the motion associated with a movement of a person that exercises.

The magnets of the magnet receiving pattern may be adapted to cooperate with windings or coils of the stationary part, such that the exercise motion control device may effectively and adjustably control the exercise motion. The exercise motion may be electrically controlled via the coils.

The magnet receiving pattern is configured for the magnets being arranged in a Halbach array. The magnet receiving pattern facilitates arranging the magnets in a Halbach array, especially if the magnets are neodymium magnets. Neodymium magnets are strong permanent magnets and may pose challenges during mounting, and the magnet receiving pattern may simplify handling the strong magnets.

Optionally, the magnet receiving pattern of the rotary part is shaped to receive the magnets in a form fit. Thus, the shape of the magnet receiving pattern may be adapted to the shape of the magnets, or vice versa. At least a portion of the magnet receiving pattern may be adapted in shape to at least a portion of the shape of the magnets, or vice versa. Thereby, the magnets may be especially properly positioned. Further, the magnets may be securely held in place. In addition the assembly may be facilitated, in particular if the magnets are strong (e.g. neodymium magnets).

The magnets may be attached to the magnet receiving pattern of the rotary part. The magnets may be glued to the magnet receiving pattern of the rotary part. When the magnet receiving pattern is shaped to receive the magnets in a form fit, only a small amount of glue may be required. The magnet receiving pattern may be configured such that the magnets are arranged adjacent one another, with no gap between consecutive magnets.

The circumferential magnet interface that comprises the magnet receiving pattern may be a radially inner surface, meaning that the magnet interface faces a rotary axis of the rotary part. Thus, centripetal forces that affect the magnets when the rotary part rotates may be effectively counteracted by the radially inner magnet interface. The magnet interface may be circular cylindrical.

Optionally, the magnet receiving pattern comprises a plurality of magnet receivers. The magnet receivers may be shaped to receive the magnets in a form fit. A form fit may be especially advantageous if the magnets are neodymium magnets.

Optionally, each magnet receiver is shaped to receive one magnet. Thereby, the (e.g. neodymium) magnets may be individually properly positioned and particularly securely attached to the rotary part. The present disclosure does not exclude each magnet receiver being shaped to receive two magnets.

Optionally, each magnet receiver is shaped as a groove. Advantages involve that the groove cross-section may be shaped to at least a portion of the shape of the magnets and that elongated magnets may be securely received. A groove may be defined as being elongated. The groove may extend along an axial direction of the rotary part. Thus, each magnet receiver may extend essentially parallel to a rotary axis of the rotary part.

Optionally, the groove has a rounded bottom. Such a groove may be easy to manufacture, e.g. by milling. A groove with a rounded bottom may further be particularly suitable for properly receiving and aligning a magnet. The magnet may comprise a convex surface that is shaped to fit the groove. Glue applied between the groove and the magnet may distribute evenly to secure the magnet to the rotary part. The glue distribution may be driven by capillary force.

In a view orthogonal to the longitudinal extension of the groove, the groove may comprise a section that is rounded, for example semicircular. Thus, the rounded bottom may be semicircular. A semicircular groove may be particularly easy to manufacture by milling. The groove may be a semicircular recess made in the circumferential magnet interface of the rotary part. The magnet receiving pattern may be formed by a plurality of preferably semicircular recesses.

Optionally, the rotary part is made of a non-magnetic material such as aluminium (aluminum in North American English), magnesium or polymer material. As is to be apprehended, by aluminium is not meant pure aluminum but an aluminum alloy. Importantly, the present rotary part does not require any back iron (or back-iron).

The rotary part may be one-piece. The rotary part may be manufactured from a single block of aluminium. Such a rotary part may be particularly light-weight and provide high torque density performance. The rotary part may comprise bearing seats. The bearing seats and the magnet receiving pattern may be formed in a single block of e.g. aluminium in the same setup.

According to the invention, the magnets are arranged in a Halbach array. Such an arrangement is of advantage for the torque density performance of the rotary part and thus of the exercise motion control device. The Halbach array arrangement facilitates providing a back-iron free rotary part.

Optionally, four consecutive magnets are arranged with their magnetization direction according to: radially inwards, first tangential direction, radially outwards, and second tangential direction. The magnets that are arranged tangentially may form return paths for the magnetic flux of the magnets that are arranged radially. In other words, the tangentially arranged magnets may complete the magnetic circuit of the radially arranged magnets. The magnets referred to herein are typically permanent magnets, preferably neodymium magnets.

Optionally, the exercise motion control device comprises a plurality of magnets, the dimensions of which are greater in the circumferential direction than in the radial direction when received in the magnet receiving pattern of the rotary part. The present disclosure does not exclude magnets of other shapes, for example having the essentially same dimension in the circumferential direction as in the radial direction. For example magnets of square cross-section. However, if the dimensions (extensions) are greater in the circumferential direction than in the radial direction, the torque density performance may be improved.

Optionally, the ratio (W/T) of the circumferential to radial direction is from <NUM> to <NUM>. A particularly advantageous ratio being <NUM> to <NUM>. If the surface of the magnet that faces the rotary part is rounded, the extension of the magnet in the radial direction is measured from the radially outer end of the magnet when mounted to the rotary part. The surface, or side, of the magnet that faces the rotary part may be of semicircular cross-section. Such a magnet may fit a semicircular groove of the rotary part.

Tests have shown that a too large ratio (W/T), i.e. quite thin magnets, may result in the magnets being demagnetised. A ratio close to <NUM> or even smaller than <NUM> results in poor torque density performance.

The magnet receiving pattern and the magnets may be configured such that the magnets are arranged adjacent one another, with no gap between consecutive magnets. In embodiments where the magnets are not arranged in a Halbach array, which are not part of the invention, alternating magnets may be arranged with the magnetization directions radially inwards and radially outwards. There may be a gap between the magnets for the return paths of the inwards and outwards fluxes.

In a view orthogonal to the longitudinal extension of the groove, the groove may comprise a section that is rounded, for example semicircular. The groove may be a semicircular recess made in the circumferential magnet interface of the rotary part. The magnet receiving pattern may be formed by a plurality of preferably semicircular recesses.

Optionally, the exercise motion control device comprises a cable that is wound in relation to the rotary part such that a rotation of the rotary part results in the cable being fed out or wound in. The exercising apparatus may then be of a type that utilises the motion control of the cable to provide resisted or assisted training. For example, the cable may be wound around the motion control interface, or around a separate spool that is rotatably connected to the rotary device. The cable may for example be <NUM> to <NUM> meters long. Rotatably connected is to be construed as when the rotary part rotates, then the separate spool rotates together with the rotary part. There may be a gear device operationally arranged between the rotary part and the separate spool.

Optionally, the exercise motion control device may replace or complement a weight stack in an exercising apparatus such as weight lifting machine In such a case, the exercise motion control device may, but need not, comprise a cable.

Optionally, the stationary part comprises a coil pattern. The magnets of the rotary part may cooperate with the coil pattern of the stationary part, such that the exercise motion control device may effectively and adjustably control the exercise motion. The coil pattern may comprise a plurality of coils. The coils may be elongated and extend at an angle α to a rotary axis A of the rotary part. The angularly arranged coils may provide a smooth motion control. Such an exercise motion control device may be essentially cogging-free.

Optionally, the rotary part comprises one essentially closed end side, one open end side and a circular cylindrical wall that extends between the essentially closed end side and the open end side. The circular cylindrical wall comprises one radially outer surface and one opposing radially inner surface. The circumferential magnet interface that comprises the magnet receiving pattern may be comprised in or may be the radially inner surface of the circular cylindrical wall. The motion control interface may be comprised in or may be the radially outer surface of the circular cylindrical wall. In a compact and light-weight design requiring few moving parts, the above-mentioned cable may be wound around the radially outer surface of the circular cylindrical wall.

Optionally, the stationary part comprises a coil pattern that comprises a plurality of coils forming slots, the magnets of the magnet receiving pattern forming poles, wherein the number slots S and poles P are 36S42P, 30S38P, 30S40P, 36S40P, 36S44P, 42S38P, 42S40P, 42S44P or 42S46P.

The exercise motion control device may function as a three phase alternating current electric machine. The rotary part of the exercise motion control device may be referred to as a rotor. The stationary part of the exercise motion control deice may be referred to as a stator. According to one aspect of the present disclosure, there is provided an exercising apparatus comprising an exercise motion control device according to claim <NUM>.

According to one aspect which is not part of the invention, there is provided an exercising apparatus comprising a stationary part and a rotary part, the rotary part comprising a circumferential magnet interface. The circumferential magnet interface comprises a magnet receiving pattern that is shaped to receive a plurality of magnets.

The exercising apparatus may be a resisted or assisted training machine that comprises a cable, typically <NUM> meters or longer, that may be fed out or wound in while being attached to a person that performs sprinting, skiing or swimming exercises. Such a resisted or assisted training machine may be portable.

Alternatively, the exercising apparatus may be a resistance training machine such as an exercising machine in a gym. Examples of exercising machines that may comprise the exercise motion control device are a cable row machine, a leg curl machine and a chest press machine. The exercise motion control device may complement or replace a weight stack that it conventionally provided in exercising machines. The exercising machine may comprise a cable, typically of a few meters in length. The exercising machine may however, be free from a cable, and instead comprise a gearing or similar that in turn is connected to a motion associated with a person that uses the exercising machine.

The exercising apparatus described herein may alternatively be referred to as a motorized (or motorised) exercising apparatus, as the exercise motion control device may function as a three phase alternating current electric machine, or three phase alternating current electric motor. The exercise motion control device may be arranged in exercising apparatuses that may be referred to as motorized training equipment, motorized fitness equipment or motorized exercise equipment.

According to one aspect of the present disclosure, there is provided a method of manufacturing an exercise motion control device of an exercising apparatus, comprising pattern forming on the rotary part a magnet receiving pattern shaped to receive a plurality of magnets, the magnet receiving pattern preferably being formed by milling. The milling may be performed in the axial direction of the rotary part. The milling of the magnet receiving pattern may be performed utilising an end mill.

The rotary part may comprise bearing seats and the method may comprise forming, e.g. machining, the bearing seats and the magnet receiving pattern in the same setup. Such a method may ensure that the magnet receiving pattern is precisely positioned in relation to the bearing seats. The magnet receiving pattern should preferably be precisely concentrically aligned with the bearing seats.

It is expected that the herein described rotary part may potentially be generally applicable to electric machines. Examples of such electric machines are electric motor and generators. Thus, according to a general aspect there is provided a rotary part, or rotor, for an electric machine, wherein a circumferential magnet interface of the rotary part comprises a magnet receiving pattern that is shaped to receive a plurality of magnets. Regarding further possible features of such a rotary part or an electric machine comprising such a rotary part, and associated advantages, reference is made to the herein described exercise motion control device, exercising apparatus and method.

The embodiments disclosed herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings. Like reference numerals refer to corresponding parts throughout the drawings, in which.

Embodiments of the present disclosure will now be described more fully hereinafter. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those persons skilled in the art.

Reference is initially made to <FIG> that discloses an exercise motion control device <NUM> for an exercising apparatus <NUM>. An exemplary exercising apparatus <NUM> is shown in <FIG>. The exercise motion control device <NUM> comprises a stationary part <NUM>, also shown in <FIG>, and a rotary part <NUM> with a circumferential magnet interface 30i and a motion control interface 30e. The rotary part <NUM> is best illustrated in <FIG>. The circumferential magnet interface 30i of the rotary part <NUM> comprises a magnet receiving pattern <NUM> that is shaped to receive a plurality of magnets <NUM> as illustrated in <FIG>.

As is particularly clear from <FIG>, in the present embodiment the magnets <NUM> are received in the magnet receiving pattern <NUM>, and are thereby attached to the rotary part <NUM>. In the present embodiment, the magnet receiving pattern <NUM> is shaped to receive the magnets <NUM> in a form fit that may be referred to as a positive fit. In addition, glue (not shown) may be applied to the magnets <NUM> and/or to the magnet receiving pattern <NUM> to attach the magnets <NUM> to the rotary part <NUM>. Thus, the glue may be applied to strengthen the positive fit with chemical attachment. The magnets <NUM> and the magnet receiving pattern <NUM> may be complementary in shape, which is particularly suitable for secure chemical attachment.

As is illustrated in <FIG> and <FIG>, the present rotary part <NUM> essentially has the shape of a circular cylinder. For weight reasons, the rotary part <NUM> is preferably thin-walled, meaning that the wall thickness of the rotary part <NUM> is small in comparison with the overall size of the rotary part <NUM>. For example, the rotary part wall thickness may be <NUM> to <NUM> percent of the diameter of the rotary part <NUM>. In some embodiments, the rotary part wall thickness may be <NUM> to <NUM> millimeters.

In some detail, the present rotary part <NUM> essentially has the shape of a cylindrical cylinder with one closed end side 30a, one open end side 30b and a cylindrical wall 30c extending between the closed end side 30a and the open end side 30b. The magnet receiving pattern <NUM> is arranged on the radially inner side of the cylindrical wall 30c that comprises the circumferential magnet interface 30i. The radially outer side of the cylindrical wall 30c comprises the motion control interface 30e. The present rotary part <NUM> further comprises a hub <NUM> that protrudes axially from the closed end side 30a to the inner of the rotary part <NUM>. The hub <NUM> may comprise at least one bearing seat.

Thus, the closed end side 30a may structurally connect the cylindrical wall 30c to the hub <NUM>. The closed end side 30a may be disc-shaped. As is illustrated, the closed end side 30a may comprise a number of openings, in the present embodiment four vent openings, and may therefore be referred to as being essentially closed. During assembly, the stationary part <NUM> may be inserted into the rotary part <NUM> through its open end side <NUM>, as is apprehended from <FIG>. As is shown, the circumferential magnet interface 30i may be a radially inner surface.

As is best shown in <FIG>, the magnet receiving pattern <NUM> comprises a plurality of magnet receivers <NUM>. The present magnet receivers <NUM> are shaped to receive the magnets <NUM> in a form fit. In the present example, each magnet receiver <NUM> is shaped to receive one magnet <NUM>. Referring to <FIG>, each magnet receiver <NUM> may be shaped as a groove. In the present example, the groove extends along the axial direction A (indicated in <FIG>) of the rotary part <NUM>. As is best illustrated in <FIG>, the groove may have a rounded bottom (the end of the groove that faces away from the center of the rotary part <NUM>). In the present example, the groove comprises a semicircular bottom.

The present rotary part <NUM> is made of aluminium. Other conceivable materials include magnesium or polymer material, such as fiber reinforced polymer material.

The magnets <NUM> are arranged in a Halbach array, as is shown in <FIG>. There, four consecutive permanent neodymium magnets <NUM> are arranged with their magnetization direction according to: radially inwards <NUM>, first tangential direction <NUM> (left), radially outwards 40N, and second tangential direction 40R (right), as indicated by the arrows in <FIG>.

Referring to <FIG> and <FIG>, each magnet <NUM> may have a greater dimension in the circumferential direction W than in the radial direction T. <FIG> discloses an exemplary magnet <NUM> comprising sides or sidewalls that may be denoted with reference to how the magnet <NUM> is to be mounted on the rotary part <NUM>. Thus, the magnet <NUM> comprises an external side 40e, an opposing internal side 40i, two opposing axial sides and two opposing circumferential sides. The magnet <NUM> has a length L in the axial direction, a width W in the circumferential direction and a thickness T in the radial direction. The ratio W/T of the width W to thickness T is approximately <NUM> to <NUM>, a suitable range being from <NUM> to <NUM>. The figures of the present disclosure show possible actual realizations of the parts and devices.

One side of the present magnet <NUM>, the external side 40e, is semicircular. The other sides are straight. Complementary, the present magnet receiving pattern <NUM> may comprise, in the present example consists of, a plurality of semicircular grooves.

In undepicted embodiments, the magnet may comprise a semicircular internal side 40i and/or opposing circumferential sides that slope towards one another. In other words, the magnet may be essentially pie-shaped or more precisely truncated pie-shaped. Such a shape may be particularly beneficial for the torque density performance.

Referring to <FIG>, <FIG> and <FIG>, the exercise motion control device <NUM> may comprises a cable <NUM> that is wound around rotary part <NUM>, more precisely around the motion control interface 30e. Thus, as is best shown in <FIG>, a rotation of the rotary part <NUM> results in the cable <NUM> being fed out or wound in.

The exercising apparatus <NUM> of <FIG> is a resisted or assisted training machine. The resisted or assisted training machine comprises a cable <NUM> that may be attached to a harness worn by a person during exercise. For example, the person may practise sprinting against resistance in order to improve acceleration, or via assisted sprint training achieve increased top speed.

The present resisted or assisted training machine comprises a battery such that the exercise motion control device <NUM> may be operated to drive the rotary part <NUM> and thereby wind the cable <NUM> in to provide assisted training. The present resisted or assisted training machine is portable, and further comprises a handle, a screen and a control device that is able to selectively brake (resisted training) or drive (assisted training) the rotary part <NUM>. The control device, or computer, is positioned inside a housing of the present resisted or assisted training machine and therefore not visible in <FIG>. How the control device functions is considered known to persons skilled in the art, is not a focus of the present disclosure, and is therefore not described in detail. The same applies to the stationary part, which is only briefly described herein. The exercise motion control device of the present disclosure, and the resisted or assisted training machine of <FIG>, function as a three phase alternating current electric machine.

In undepicted embodiments, the exercise motion control device <NUM> may replace or complement a weight stack in an exercising apparatus. Thereby, the weight of the exercising apparatus may be greatly reduced, and the resistance may be controlled accuracy of over a wide range. The exercise motion control device <NUM> may allow faster exercise movements as compared to a conventional weight stack.

Referring to <FIG>, the stationary part <NUM> may comprise comprises a coil pattern <NUM> comprising a plurality of coils <NUM>. As is shown, the coils <NUM> may be elongated and extend at an angle α to a rotary axis A of the rotary part <NUM>.

In the present example, the exercise motion control device <NUM> is of a <NUM>-slot-<NUM>-pole 36S42P configuration, which is believed optimal for the current purpose. Other conceivable configurations are 30S38P, 30S40P, 36S40P, 36S44P, 42S38P, 42S40P, 42S44P or 42S46P.

<FIG> illustrates the steps of an exemplary method <NUM> of manufacturing a rotary part <NUM> for an exercise motion control device <NUM> of an exercising apparatus <NUM>, for example of the types described herein.

The method may comprise providing <NUM> a precursor, for example in the form of a solid circular cylindrical block of aluminium. Suitable alloys include <NUM>-T6 aluminium and <NUM>-T6 aluminium.

The method may next involve forming <NUM>, e.g. by machining such as turning, the precursor into the above described semi-finished rotary part <NUM> essentially having the shape of a cylindrical cylinder with one closed end side 30a, one open end side 30b and a cylindrical wall 30c extending between the closed end side 30a and the open end side 30b.

Next, the method may comprise pattern forming <NUM>, e.g. by machining such as milling, the magnet receiving pattern <NUM> in the semi-finished rotary part <NUM>. This pattern forming step <NUM> may in addition comprise forming the vent openings and the bearing seats. By forming the magnet receiving pattern <NUM> and the bearing seats in the same setup, tight tolerances may be achieved. The method <NUM> may further comprise attaching the magnets <NUM> as has been described, and assembling the other components of the exercise motion control device <NUM>.

Modifications and other variants of the described embodiments will come to mind to ones skilled in the art having benefit of the teachings presented in the foregoing description and associated drawings. Therefore, it is to be understood that the embodiments are not limited to the specific example embodiments described in this disclosure and that modifications and other variants are intended to be included within the scope of the invention, which is defined in the appended claims.

Claim 1:
An exercise motion control device (<NUM>) for an exercising apparatus (<NUM>), the exercise motion control device (<NUM>) comprising
- a stationary part (<NUM>),
- a rotary part (<NUM>) with a circumferential magnet interface (30i), and
- a plurality of magnets (<NUM>) arranged in a Halbach array,
wherein the magnet interface (30i) comprises a magnet receiving pattern (<NUM>) that is shaped to receive the plurality of magnets (<NUM>) and
the rotary part (<NUM>) comprises a motion control interface (30e) that is adapted to control an exercise motion.