EP1776988B1 - Drive unit - Google Patents

Abstract

The unit has a stator (2), and a flywheel (4) that is pivoted by a bearing device (8) with respect to the stator, where the flywheel is arranged radially within the stator. The bearing device surrounds the flywheel and includes rotatable rolling bodies (10), where the stator has a bearing surface (12) that is arranged in an area of its inner surface and the flywheel has another bearing surface (14) that is arranged in an area of its peripheral surface for the rolling bodies. The rolling bodies are arranged spaced from each other by a bearing ring (20, 22) in a circumferential direction.

Description

The invention relates to a drive unit for exercise equipment according to the features specified in the preamble of claim 1.

From the US 5,490,824 Such a drive unit with a stator is known, which has two bearing arrangements for a shaft of a flywheel in the center. The shaft is rotatably connected to the flywheel and penetrates this in the center. The shaft protrudes with its ends on both sides of the stator, wherein at said ends levers are arranged with handles, by means of which a trainee can rotate the flywheel. On the peripheral surface of the flywheel, a band brake is arranged, wherein the braking torque is adjustable by means of a clamping device arranged in the stator.

Furthermore, from the DE 102 30 880 A1 an inner tangential drive exercise machine is known, which includes a drive device with an eccentric shaft. This is relatively attached to a position of a circular tangent point in the lower part of an inner circle of the inside of a stator rotatably mounted wheel. A stator is absent, and inside the movable wheel there is provided an inner band body, the left and right upper portions of which are each provided with a rail device for forming three points with the driving device with which an inverse and tangential movement is achieved in the inner part of a composite frame becomes.

Drive units of the type mentioned can be designed as components of training devices of known design, such as ergometers, exercise bikes, crosstrainers, elliptical trainers or the like. The flywheel is rotatably supported by means of the bearing assembly with respect to a stator, which is connected to the training device in a suitable manner or as part of the training device, for example, the frame is formed. The force or torque introduction of a person exercising on the training device via chain drives, belt drives, cranks or the like, which are actuated by the exercising person on foot, handle bars or the like. Such drive units have a not inconsiderable volume of construction, and to avoid injury hazards additional measures, such as fenders or covers required.

On this basis, the invention has the object, with a small design effort to form the drive unit to the effect that a compact design is achieved and beyond the integration of the drive unit in training devices of different types can be realized in a simple manner. The drive unit is to require a low production and assembly costs, with a few components an economical and nevertheless functionally reliable design should be achieved.

The solution of this task is carried out according to the features specified in claim 1

in the drive unit according to the invention, the flywheel is arranged radially inside the stator, wherein the flywheel and the stator have mutually associated and spaced opposite annular raceways for rolling elements of the bearing assembly. The stationary arranged and preferably annular stator surrounds the inner flywheel to form a gap, wherein in said space, the bearing assembly is arranged with the rotatable Rollkörpem. The running surfaces and the rolling bodies are designed and / or matched to one another such that the flywheel is guided and secured both radially and axially in the stator. The running surface of the stator is arranged in the region of its inner surface, and the running surface of the flywheel is provided in the region of the outer or peripheral surface of the flywheel. The annularly extending in the circumferential direction treads advantageously have a concave contour and accordingly matched the rolling elements or rollers in cross-section a convex outer contour such that a secure guidance and storage of the flywheel is ensured both in the axial and in the radial direction. Of course, in the context of the invention, the alternative embodiment is such that the running surfaces have a convex contour and the rollers have a concave outer contour in cross section.

The rollers are arranged spaced apart by means of at least one bearing ring in the circumferential direction, wherein in a preferred manner the force or torque introduction via the bearing ring, for this purpose owns the two bearing rings expediently aligned to the virtual axis of rotation of the flywheel pins, to which, for example, pedals Immediate action by the feet of a person exercising or for the articulation of cranks, connecting rods or the like. In a particular embodiment, the bearing assembly and / or the rolling bodies and / or their bearings are designed with free-wheeling property to the effect that when the force or torque introduction suspension of the flywheel can continue its rotational movement. The rolling bodies mentioned are rotatable with respect to the or the bearing rings by means of pins or axles, suitably rotatably mounted with the interposition of small ball or roller bearings. Conveniently, the rolling elements are designed as commercial wheels of inline skaters. The preferred annular stator is advantageously made of steel and may be integrally formed as well as from each other in a suitably connected segments. It should be particularly noted that the flywheel and the annular stator are arranged coaxially with each other and thus in Compared to known drive units, especially in the axial direction have a narrow and compact geometry, especially since the previously required, in the axial direction on the outer contour of the flywheel outstanding axis or shaft and thus located next to the flywheel components for supporting and supporting the flywheel are unnecessary.

Particular embodiments and further developments of the invention are specified in the dependent claims and the following description of a particular embodiment.

Figur 1

eine perspektivische und teilweise geschnittene Darstellung der Antriebseinheit,

Figur 2

eine Detailansicht der Antriebseinheit aus einer anderen Perspektive.

The invention will be explained in more detail with reference to the embodiment shown in the drawing, without being limited in this respect. Show it:

FIG. 1

a perspective and partially sectional view of the drive unit,

FIG. 2

a detailed view of the drive unit from a different perspective.

FIG. 1 shows the designed as a ring and in particular made of steel stator 2, which surrounds the preferably formed as a disc flywheel 4 to form a gap 6 at a predetermined radial distance. In the intermediate space 6, the bearing assembly 8 is provided with a number of particular eight rolling elements 10. The number of rolling elements 10 can be specified hereby deviating from the requirements. The inner surface of the stator 2 is formed as a running surface 12, and corresponding thereto, the peripheral surface of the flywheel 4 is formed as a running surface 14 for the outer surfaces 16 of the rolling bodies 10 adapted thereto. The rolling elements 10 are preferably designed as rollers of inline skaiem and suitably contain an outer sheath or ring 18 made of a predetermined elastic material, such as elastomer, rubber or plastic, whereby the running properties of the flywheel 4 optimized, manufacturing tolerances balanced and running noise can be reduced. The running surfaces 12, 14 are concave, and corresponding thereto, the outer surface 16 is convexly formed such that a functionally reliable axial and radial guidance of the inner flywheel 4 is ensured. Alternatively, in the context of the invention, the running surfaces 12, 14 may be convex and the outer surface 16 may be concave. Furthermore, the rolling bodies may for example also be designed as cylindrical rollers and correspond to the running surfaces 12, 14 have U-shaped cross-sections for the purpose of radial and axial bearing and guiding the flywheel 4 in the annular stator. 2

The bearing assembly 8 includes two axially spaced-apart bearing rings 20, 22, between which said rolling elements 10 are rotatably mounted about axes 24. The axes 24 are expediently formed by screws, by means of which a predetermined axial distance of the two fixedly connected by means of said screws bearing rings 20, 22 is defined. The rolling elements 10 are rotatably supported by means of small roller or roller bearings 26, 28 on the respectively assigned screw or axle 24. Preferably, the free-wheeling function is integrated into the reel body 10 or its bearings 26, 28 to the effect that the rotating flywheel 4 continues to rotate even when the rotational movement of the bearing assembly 8 is reduced or stopped.

For driving the flywheel 4 or for introducing a torque at least one of the bearing rings 20, 22 includes a pivot pin 30 for the purpose of articulation of a crank, a connecting rod, a pedal, a rotary lever or the like. As shown, both bearing rings 20, 22 each contain a pivot pin 30, offset in the circumferential direction by 180 ° to each other, so that, for example, pedals can be fastened, via which on a training device whose frame 32 is partially indicated, the person exercising by means of the feet can initiate the force or the torque in the drive unit. The stator 2 is connected to the training device or its here exemplary and partially indicated frame 32 in a suitable manner.

It should be expressly understood that with the drive unit according to the invention, a compact space and weight-saving design is realized, wherein the outer radius of the stator 2 is preferably in the order of 200 mm to 250 mm and thus the radial distance of the pivot pin 30 in the example at bicycles usual size of 150 mm to 190 mm. Furthermore, due to the coaxial arrangement of stator 2 and flywheel 4, which is arranged radially inside of the stator 2, the drive unit has a rather small axial length corresponding to the width 34 of the outer annular stator 2. The width 34 of the stator 2 is on the order of 30 mm to 40 mm, and the width or axial length of the flywheel 4 is of the same order of magnitude. It is understood that the dimensions of the drive unit can be adapted to the operational requirements, in particular taking into account the moment of inertia of the flywheel 4, and accordingly can be specified.

FIG. 2 shows in a detailed view of the drive unit, in which case the already mentioned with the pivot pin 30 connected in a known manner pedal 36 is recognizable for the purpose of direct drive. By way of example, the measures of radius 231 for the outer circumference of the stator 2 and the outer diameter 288 of the flywheel 4 and the width or axial length of 35 mm of the stator 2 are also given. The flywheel 4 is preferably constructed of two steel discs, which for example have a thickness in the order of 8 mm to 10 mm. By appropriate specification of the axial thickness of the flywheel 4 and the steel disks mentioned the flywheel and thus the moment of inertia can be easily adapted to the respective requirements, the remaining components of the drive unit can be maintained unchanged. Instead of the disk-shaped configuration, the flywheel may also be annular in shape within the scope of the invention.

reference numeral

2

stator

4

flywheel

6

gap

8th

bearing arrangement

10

Rolling body / roller

12

Tread of 2

14

Tread of 4

16

Outer surface of 10

18

Coat / ring of 10

20, 22

bearing ring

24

Axis of 10

26, 28

Warehouse of 10

30

pivot

32

frame

34

width

36

pedal

Claims (10)

1. A drive unit for training devices, including a stator (2) and a flywheel (4), which is mounted rotatably with respect to the stator (2) via a bearing arrangement (8), wherein the flywheel is arranged radially inside the stator (2),
   characterised in that
   the bearing arrangement (8) surrounds the flywheel (4) and contains rotating rolling elements (10), wherein the stator (2) has a contact surface (12) arranged in the area of its inner surface and the flywheel (4) has a contact surface (14) in the area of its circumferential surface for the rolling elements (10), and that the rolling elements (10) are disposed at a distance from each other about the circumference by means of a bearing race (20, 22).
2. The drive unit as recited in claim 1,
   characterised in that
   the bearing arrangement (8) and/or the bearing race (20, 22) are arranged coaxially with the flywheel (4) and preferably surround the flywheel.
3. The drive unit as recited in either of claims 1 or 2,
   characterised in that
   the contact surfaces (12, 14) and the outer surfaces (16) of the rolling elements (10) corresponding therewith are designed to enable axial and radial support and/or guidance with respect to the stator (2) for the flywheel (4) located inside.
4. The drive unit as recited in any of claims 1 to 3,
   characterised in that
   the cross section of the contact surfaces (12, 14) is concave in shape, and also that the cross section of the outer surfaces (16) have a correspondingly convex shape, or vice versa, and/or that the rolling elements (10) are furnished on the outside with claddings or rings (18) made from an elastic material such as elastomer, rubber or plastic.
5. The drive unit as recited in any of claims 1 to 4,
   characterised in that
   the at least one bearing race (20, 22) has at least one pivot pin (30) for transferring load or torque, and/or that the baring arrangement is furnished with two bearing races (20, 22) that are arranged with axial separation from one another and permanently attached to one another, and between which the rolling elements (10) are disposed.
6. The drive unit as recited in claim 5,
   characterised in that
   the fixing elements, which are particularly provided as screws for attaching the bearing races (20, 22) at a distance from one another, have the form of spindles (24) or shafts of the rolling elements (10), wherein the rolling elements (10) are arranged so as to be rotatable about the spindles (24) or shafts via bearings (26, 28).
7. The drive unit as recited in any of claims 1 to 6,
   characterised in that
   the stator (2) is constructed as a ring that encloses the flywheel (4), thereby forming a clearance (6), wherein the stator (2) is preferably made from steel, and/or that the stator (2) is constructed as a single item or that the stator (2) is constructed from at least two permanently attached segments.
8. The drive unit as recited in any of claims 1 to 7,
   characterised in that
   the flywheel (4) arranged coaxially inside the stator (2) is constructed in the form of a disc and/or that the flywheel (4) is constructed from at least two discs and/or that the flywheel (4) is constructed from steel.
9. The drive unit as recited in any of claims 1 to 8,
   characterised in that
   the two bearing races (20, 22) are each furnished with a pivot pin (30), wherein these two pivot pins (30) are arranged so as to be offset circumferentially with respect to one another by essentially 180°, and are separated in opposite axial directions by the respective bearing race (20, 22).
10. The drive unit as recited in any of claims 1 to 9,
    characterised in that
    the bearing arrangement (8) and/or the rolling elements (10) and/or their bearings (26, 28) thereof are constructed as a free wheel in such manner that the flywheel (4) remains in the position it has reached when the rotating motion of the bearing arrangement (8) and/or of the bearing races thereof (20, 22) is reduced.

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