CN112178055A

CN112178055A - Linear bearing unit with sound insulation device

Info

Publication number: CN112178055A
Application number: CN202010630970.5A
Authority: CN
Inventors: 乌维·迈尔; 丹尼尔·林德; 亨里克·威尔德; 马提亚斯·费舍尔; 欧文·约书亚; 马尔科·卢克斯
Original assignee: SKF Motion Technologies AB
Current assignee: Ewellix AB
Priority date: 2019-07-05
Filing date: 2020-07-03
Publication date: 2021-01-05
Anticipated expiration: 2040-07-03
Also published as: CN112178055B; DE102019004632A1

Abstract

The invention relates to a linear bearing unit (2, 19) comprising: a linear bearing (5), the linear bearing (5) having a first and a second end side (7, 8); and a through opening (9), the through opening (9) extending from the first end side (7) to the second end side (8) for the passage of the guide shaft (3). According to the invention, the linear bearing unit (2, 19) is equipped with a sound insulation device (6, 20), wherein the sound insulation device (6, 20) comprises an insulating body (11) for sound insulation, which is arranged on one of the two end sides (7, 8) of the linear bearing (5).

Description

Linear bearing unit with sound insulation device

Technical Field

The present invention relates to a linear bearing unit, comprising: a linear bearing with first and second end faces; and a through opening extending from the first end face up to the second end face for passage of the guide shaft. The invention also relates to a linear bearing system with such a linear bearing unit and to an exercise device with at least one such linear bearing unit.

Background

Linear bearings, in particular linear ball bearings, are used in various technical fields for the linear guidance of components along an axis with as little friction as possible. For example, linear bearings in exercise devices are used for this purpose.

In operation of a device equipped with a linear bearing, operational noise is generated due to relative movement between the linear bearing and the shaft, which may be undesirable depending on the application and environmental conditions. In the case of linear ball bearings, this operating noise can be perceived as a slight sawing or tapping sound, for example, and can be traced back to the collision of the rotating balls of the linear bearings, in particular.

One method of reducing operating noise in equipment equipped with linear bearings is to lubricate the linear bearings with a lubricant having a noise reducing effect. In some applications, however, a sufficiently effective noise reduction that meets the respective requirements cannot be achieved by this method.

Disclosure of Invention

The object of the invention is to achieve an effective reduction of operational noise in a device equipped with one or more linear bearings.

According to the invention, this object is achieved by a linear bearing unit according to claim 1, a linear bearing system according to claim 12 and an exercise device according to claim 15.

Preferred embodiments of the invention are given in the further claims and in the following description.

The linear bearing unit according to the present invention includes: a linear bearing having a first end face and a second end face; and a through opening extending from the first end face to the second end face to guide the shaft to pass through. Furthermore, the linear bearing unit according to the invention is equipped with a sound insulation device comprising an insulator for sound insulation, which insulator is arranged on one of the two end sides of the linear bearing.

The invention is based on the recognition that operating noise generated during the relative movement between the shaft and the linear bearing originates from the interior of the linear bearing, wherein sound waves in the form of airborne sound (Luftschall) can be transmitted directly into the environment through the through-opening of the linear bearing and/or in the form of structure sound

May propagate from the linear bearing to an adjacent component and from there to the environment.

By means of the insulating body of the sound insulation device arranged on the end side of the linear bearing, a reduction of the transmission of airborne and/or structural sound to the linear bearing environment can be achieved. In particular, the insulator makes it possible to achieve a reduction in the transmission of structural sound from the linear bearing through the end side of the linear bearing to a component arranged adjacent to the end side and/or a reduction in the propagation of airborne sound from the through-opening of the linear bearing.

The expression that the spacer is "arranged on one of the two end sides of the linear bearing" does not necessarily mean that the spacer is in contact with the linear bearing, or more precisely with one of the two end sides of the linear bearing. If desired, another element may be located between the isolator and the linear bearing. This means that the spacer can be arranged on one of the two end sides of the linear bearing, in particular with the other element in the middle. However, in an alternative embodiment of the invention, it can be provided that the spacer is in contact with the linear bearing, or rather one of the two end sides of the linear bearing.

The linear bearings of the linear bearing unit are preferably designed as linear ball bearings. Linear ball bearings are characterized by particularly low frictional resistance and are therefore well suited for applications where it is desirable or required to guide a component along a shaft with particularly low friction, such as is common in exercise devices.

In a preferred embodiment of the invention, the spacer is formed in one piece. Alternatively, the insulating body may be composed of a plurality of individual parts, in particular of identical individual parts, which may for example be arranged adjacent to one another.

Further, it is preferable that the spacer has a through opening for passing the guide shaft. The diameter of the through-opening of the insulating body is advantageously at most equal to the diameter of the through-opening of the linear bearing. This achieves that the insulating body surrounds the shaft in an air-tight manner, whereby the propagation of airborne sound from the through-opening can be reduced particularly effectively.

The insulating body is advantageously designed to be annular, in particular with a rectangular or square cross-sectional shape.

The insulating body may for example be made of or comprise a foam material. Foam materials generally have good sound insulation and are inexpensive. Alternatively, the insulation may be made of or contain other insulation materials.

It is furthermore advantageous if the material of which the insulating body is made is an elastic material. This makes it possible to achieve that the spacer adapts with the diameter of its through opening to the diameter of the shaft.

It is also advantageous to impregnate the insulation with a lubricant for lubricating the linear bearing. Preferably, upon relative movement between the shaft and the linear bearing, the lubricant contained in the isolator reaches onto the shaft and from there into the linear bearing. By means of this lubricant, additional lubrication of the linear bearing can be achieved, which can lead to a further reduction in operating noise. In this case, the linear bearing is preferably not equipped with a seal, so that the lubricant can reach the linear bearing unhindered.

Furthermore, it can be provided that the sound insulation device comprises an insulator housing, in particular an annular insulator housing, in which an insulator is arranged and which has a through-opening for the passage of the guide shaft. The insulator housing is preferably in contact with that end side of the linear bearing on which the insulator is arranged. The isolator housing enables the isolator to be easily installed within the upper housing that receives the linear bearing unit.

Advantageously, the insulator is not covered by the insulator housing at its through opening. Thereby, the spacer may contact the shaft to seal the linear bearing unit with respect to the shaft and/or to supply the linear bearing with lubricant possibly contained within the spacer through the shaft.

The insulator housing can be constructed in multiple parts, in particular in two parts. For example, the isolator housing may have a main housing portion and a housing cover portion. The isolator housing and its housing cover part are preferably in contact with that end side of the linear bearing on which the isolator is arranged.

In a further embodiment variant, it can be provided that the isolator housing is designed without a housing cover part and that the isolator is in contact with the linear bearing on its side facing the linear bearing.

It can further be provided that the sound insulation device has a sound insulation housing, in particular a two-part sound insulation housing, in which the linear bearing and the insulating body are arranged and which has a through-opening for the passage of the guide shaft. The transmission of structural noise from the linear bearing to a superordinate housing receiving the linear bearing unit is reduced by the sound-insulating housing.

The sound-insulating housing is preferably a plastic housing, in particular since plastics generally have a good sound-insulating effect.

In an embodiment variant in which the sound insulation device comprises a sound insulation housing, the insulating body is preferably in contact with the end side of the linear bearing with its side facing the linear bearing, and the insulating body is preferably in contact with the inner face of the sound insulation housing with its side facing away from the linear bearing.

Furthermore, the linear bearing unit may comprise a force transmission element arranged between the sound-proof housing and the linear bearing, which force transmission element is preferably in contact with the sound-proof housing and the linear bearing. The force transmission element may in particular be made of steel or possibly of another metal. The force transmission element advantageously surrounds a sub-section of the linear bearing. It is particularly preferred to design the force transmission element as a ring and to surround a sub-part of the linear bearing on its circumference.

The sound-insulating housing preferably has a stepped, axially symmetrical cavity with a plurality of portions of different diameters. The diameter of a portion of the cavity may be equal to the outer diameter of the linear bearing, for example. The diameter of the other part of the cavity may for example be equal to the outer diameter of the spacer. The diameter of the still further portion of the cavity may be equal to the outer diameter of the force transmitting element.

The linear bearing unit optionally has a bearing housing in which the linear bearing and the sound insulation are arranged. The bearing housing suitably has a through opening for the passage of the guide shaft. The bearing housing is preferably a metal housing, in particular an aluminum housing.

For example, the spacer housing, if present, can be pressed into the bearing housing. This means that the insulator housing can be connected with the bearing housing by a press fit.

The sound-insulating device may comprise, in addition to the aforementioned insulating body, another insulating body for sound insulation. Advantageously, one of the two insulating bodies of the sound-insulating device is arranged on the first end side of the linear bearing, while the other of the two insulating bodies of the sound-insulating device is arranged on the second end side of the linear bearing. This makes it possible to obtain the same advantages as the aforementioned insulator of the sound-insulating device with the other insulator on the other end side of the linear bearing. It is also suitable for the further insulating body to have a through-opening for the passage of the guide shaft.

In particular, the aforementioned separator and the other separator may be designed to be identical to each other. In this case, the features mentioned above and/or further below in relation to the aforementioned separator may similarly relate to the further separator.

The linear bearing system according to the invention comprises a linear bearing unit according to the invention and a shaft guided through the linear bearing unit. In the linear bearing system according to the invention, it is provided that the insulator of the sound insulation device of the linear bearing unit surrounds the subsection of the shaft in a gas-tight manner on the circumference of the subsection of the shaft.

If the sound insulation device of the linear bearing unit has, in addition to its aforementioned insulation, an optional further insulation, it is preferred if this further insulation also surrounds the shaft in a gas-tight manner on its circumference.

The thickness of the insulating body of the sound-insulating device in the axial direction of the shaft advantageously corresponds to at least 5%, preferably at least 10%, of the diameter of the shaft. It is further advantageous if the thickness of the insulating body of the sound-insulating device in the radial direction of the shaft corresponds to 5%, preferably at least 10%, of the diameter of the shaft. The size of the separator can realize good sound insulation effect of the separator.

Furthermore, the wall thickness of the optional sound-insulating housing of the sound-insulating device in the radial direction of the shaft may correspond to at least 2%, preferably at least 5%, of the diameter of the shaft. The wall thickness of the optional sound-insulating housing in the axial direction of the shaft preferably corresponds to at least 2%, preferably at least 5%, of the diameter of the shaft. The sound insulation shell can achieve good sound insulation effect through the size of the sound insulation shell.

The fitness device according to the invention may be, for example, a leg press, which comprises at least one linear bearing unit according to the invention or at least one linear bearing system according to the invention.

Drawings

The invention is explained in more detail below with reference to the drawings showing embodiments of the invention. Identical or functionally identical elements are provided with the same reference symbols, where appropriate. The invention is not limited to the embodiments illustrated in the drawings nor to the functional features. The above description and the following description of the drawings contain many features, some of which are summarized in the dependent claims. However, the person skilled in the art will also consider these features separately and combine them into useful further combinations. In particular, these features may be combined individually and in any suitable combination with the linear bearing unit according to the invention, the linear bearing system according to the invention and/or the exercise device according to the invention.

The figures are as follows:

fig. 1 shows a perspective view of a linear bearing system comprising a linear bearing unit and a shaft guided through the linear bearing unit;

FIG. 2 shows an exploded view of a linear bearing unit of the linear bearing system of FIG. 1;

FIG. 3 shows an exploded view of the isolator and isolator housing of the linear bearing unit of FIG. 2;

fig. 4 shows a perspective illustration of a further linear bearing system comprising a linear bearing unit and a shaft guided through the linear bearing unit;

FIG. 5 shows an exploded view of the shaft and linear bearing unit of the linear bearing system of FIG. 4;

fig. 6 shows a sectional illustration of a linear bearing unit of the linear bearing system in fig. 4, wherein the linear bearings of the linear bearing unit are not illustrated;

figure 7 shows a schematic illustration of an exercise device with a plurality of linear bearing units.

Detailed Description

Fig. 1 shows a perspective illustration of a first linear bearing system 1. This linear bearing system 1 comprises a linear bearing unit 2 and a shaft 3, the shaft 3 being guided through the linear bearing unit 2 and the linear bearing unit 2 being linearly movable along the shaft 3.

In fig. 1, the bearing housing 4 of the linear bearing unit 2 and a part of the shaft 3 guided through the linear bearing unit 2 are shown from an oblique upper perspective. The bearing housing 4 is preferably a metal housing, in particular an aluminum housing.

Fig. 2 shows the linear bearing unit 2 of the linear bearing system 1 from fig. 1 in an exploded view. In contrast to fig. 1, the upper side of the bearing housing 4 of the linear bearing unit 2 is not visible in fig. 2, but rather the lower side thereof.

The linear bearing unit 2 comprises a linear bearing 5 and a sound-insulating device 6. In the assembled state of the linear bearing unit 2 (see fig. 1), the linear bearing 5 and the sound insulation device 6 are arranged within the bearing housing 4.

In the present exemplary embodiment, the linear bearing 5 is a linear ball bearing, i.e. a linear bearing having balls as rolling bodies. Furthermore, the linear bearing 5 has a first end side 7, a second end side 8 and a through-opening 9 extending from the first end side 7 to the second end side 8.

The sound insulation device 6 comprises two annular insulating body housings 10, which are designed to be structurally identical to one another and in which annular insulating bodies 11 for sound insulation are arranged in each case (see fig. 3). One of the two insulated housings 10 can be seen in fig. 1, wherein each of the two insulated housings 10 of the sound-insulating device 6 is pressed into the bearing housing 4. In the assembled state of the linear bearing unit 2, one of the two isolator housings 10 is arranged on the first end side 7 of the linear bearing 5, while the other of the two isolator housings 10 is arranged on the second end side 8 of the linear bearing 5, wherein the two isolator housings 10 are in contact with the linear bearing 5, more precisely with the end faces 7, 8.

As can be seen from fig. 2, in addition to the linear bearing 5, the bearing housing 4 and the two isolator housings 10 each comprise a through opening 9 for the passage of the guide shaft 3.

Fig. 3 shows an exploded illustration of one of the two insulator housings 10 and the insulator 11, said insulator 11 being arranged within the insulator housing 10 in the assembled state of the insulator housing 10. Since the two insulator housings 10 of the sound-insulating device 6 are designed to have the same configuration as each other and the insulators 11 are the same as each other, the following description is similarly applied to the other insulator housing 10 which is not illustrated in fig. 3.

The insulator housing 10 illustrated in fig. 3 is designed in two parts. The separator housing 10 includes a main housing portion 12 and a housing cover portion 13. The main housing portion 12 includes a side wall 14 with a plurality of notches 15 and a bottom wall 16. The housing cover section 13 comprises a plurality of radial projections 17, which radial projections 17 engage in the indentations 15 of the side walls 14 of the body housing section 12 in the assembled state of the insulator housing 10.

As can be seen from fig. 3, the two

housing parts

12, 13 and the spacer 11 described above each have a through opening 9 for the passage of the guide shaft 3. The diameter of the through-opening 9 of the insulating body 11 is selected such that, in the assembled state of the linear bearing system 1 (see fig. 1), the insulating body 11 surrounds the sub-portion of the shaft 3 in an air-tight manner on its circumference.

The separator 11 is made of a foam material and has a rectangular sectional shape. The insulator 11 is not covered by the insulator housing 10 at its through opening 9. Furthermore, the insulator 11 is impregnated with a lubricant for lubricating the linear bearing 5, which is introduced into the linear bearing 5 through the shaft 3 upon relative movement between the shaft 3 and the linear bearing unit 2. The thickness of the insulating body 11 in the axial direction of the shaft 3 corresponds to approximately 22% of the diameter of the shaft 3. The thickness of the spacer 11 in the radial direction of the shaft 3 corresponds to approximately 17% of the diameter of the shaft 3.

Another embodiment of the present invention is described below. If the same reference numerals as in fig. 1 to 3 are used, they denote the same or corresponding elements of the embodiments. However, identical or corresponding elements of the exemplary embodiments may also be denoted by different reference numerals, if appropriate.

Fig. 4 shows a perspective view of the second linear bearing system 18. This linear bearing system 18 comprises a linear bearing unit 19 and a shaft 3, the shaft 3 being guided through the linear bearing unit 19 and the linear bearing unit 19 being linearly movable along the shaft 3.

The linear bearing unit 19 of this linear bearing system 18 comprises a sound-insulating device 20 with an axially symmetrical, multi-part sound-insulating housing 21 made of plastic, which sound-insulating housing 21 comprises two

identical housing halves

22, 23. A linear bearing 5, in particular a linear bearing 5 designed as a linear ball bearing, is arranged within the sound-insulating housing 21 (see fig. 5).

The linear bearing unit 19 may optionally comprise a bearing housing, in particular a metal bearing housing, in which the sound-insulating housing 21 and the linear bearing 5 arranged in the sound-insulating housing 21 can be arranged. Such an alternative bearing housing is not shown in fig. 4 or fig. 5 and 6.

Fig. 5 shows an exploded view of the linear bearing system 18 of fig. 4.

The aforementioned linear bearing 5 of the linear bearing unit 19 of the linear bearing system 18 can be seen in fig. 5. The linear bearing 5 has a first end side 7, a second end side 8 and a through opening 9 extending from the first end side up to the second end side for the passage of the guide shaft 3.

The sound-insulating housing 21 of the sound-insulating device 20 has a wall thickness in the axial direction of the shaft 3 of about 30% of the diameter of the shaft 3 and a wall thickness in the radial direction of the shaft 3 of about 14% of the diameter of the shaft 3.

Furthermore, two further elements of the sound-insulating device 20 of the linear bearing unit 19 can be seen in fig. 5. These two further elements are two annular insulating bodies 11 for sound insulation.

In the assembled state of the linear bearing unit 19 (see fig. 4), one of the two spacers 11 is arranged on the first end side 7 of the linear bearing 5, while the other of the two spacers 11 is arranged on the second end side 8 of the linear bearing 5. In this state, the insulating body 11 is in contact with the linear bearing 5 with its side facing the linear bearing 5, more precisely with the end sides 7, 8 of the linear bearing 5, while the respective insulating body 11 is in contact with the inner face of one of the

housing halves

22, 23 of the sound-insulating housing 21 with its side facing away from the linear bearing 5.

With regard to its further features, the two insulating bodies 11 of the sound-insulating device 20 correspond to the insulating bodies 11 of the first linear bearing system 1 described previously in fig. 1 to 3, so reference can be made to the above description of the insulating bodies 11 of the first linear bearing system 1.

As can be seen from fig. 5, in addition to the linear bearing 5, the two

housing halves

22, 23 and the two insulating bodies 11 of the sound-insulating housing 21 each have a through-opening 9 for the passage of the guide shaft 3.

The linear bearing unit 19 further comprises an annular force transmission element 24, said force transmission element 24 preferably being made of steel. In the assembled state of the linear bearing unit 19 (see fig. 4), the force transmission element 24 is arranged between the sound-proof housing 21 and the linear bearing 5, wherein the force transmission element 24 is in contact with the linear bearing 5 and the sound-proof housing 21 and surrounds the subsection of the linear bearing 5 on its outer circumference. It is achieved that the force-transmitting element 24, which transmits forces from any (bearing) housing surrounding the linear bearing unit 19 onto the linear bearing 5, advantageously has such a strength that the linear bearing unit 19 does not deform during operation. This ensures a constant guiding accuracy of the linear bearing unit 19.

Fig. 6 shows a sectional illustration of the linear bearing unit 19 of the linear bearing system 18 in fig. 4 and the shaft 3 guided through the linear bearing unit 19, wherein, however, the linear bearing 5 of the linear bearing unit 19 is illustrated in fig. 6.

As can be seen from fig. 6, sound-insulating housing 21 has a stepped cavity for receiving linear bearing 5, two insulating bodies 11 and force transmission element 24. The diameter of the cross section of the cavity of sound-proof housing 21 is equal to the outer diameter of force-transmitting element 24. In addition, the cavity comprises two portions having a diameter equal to the outer diameter of the linear bearing 5; and two portions having a diameter equal to the outer diameter of the separator 11.

Fig. 7 shows a schematic illustration of an exercise device 25, said exercise device 25 more precisely being a leg press.

Exercise device 25 has a frame 26 and a tread 27 secured to frame 26. The fitness device 25 further comprises two shafts 3 fixed to the frame 26 and arranged parallel to each other, said shafts 3 being arranged adjacent to each other such that only one of the two shafts 3 is visible in fig. 7. Furthermore, the exercise device 25 comprises a bearing housing 28 on each of the two shafts 3, in which bearing housing 28 two bearing units 29 are arranged one after the other. Furthermore, the fitness device 25 has a seat 30, which seat 30 is connected to the bearing housing 28 and can be moved along the shaft 3 by means of a bearing unit 29.

The bearing unit 29 of the fitness device 25 may, for example, be designed similarly to the bearing unit 2 of the first linear bearing system 1 (see fig. 1 to 3), wherein in this case the bearing housing 28 of the fitness device 25 may be provided as a replacement for the bearing housing 4 illustrated in fig. 1 and 2, if necessary. Alternatively, the bearing unit 29 of the fitness device 25 may, for example, be designed like the bearing unit 19 of the second linear bearing system 18 (see fig. 4 to 6).

The present invention has been described in detail with reference to the illustrated exemplary embodiments. The invention is not limited to or by the examples disclosed. Other variations from these exemplary embodiments may be made by those skilled in the art without departing from the concept on which the invention is based.

List of reference numerals

1 linear bearing system

2 Linear bearing Unit

3 shaft

4 bearing housing

5 Linear bearing

6 Sound insulation device

7 end side

8 end side

9 through opening

10 insulator housing

11 spacer

12 main housing part

13 cover part of the housing

14 side wall

15 gap

16 bottom wall

17 projection

18 linear bearing system

19 linear bearing unit

20 sound insulation device

21 sound insulation shell

22 housing halves

23 housing halves

24 force transmitting element

25 body-building device

26 frame

27 tread

28 bearing housing

29 bearing unit

30 seat

Claims

1. A linear bearing unit (2, 19) comprising: a linear bearing (5), the linear bearing (5) having a first end side (7) and a second end side (8); and a through opening (9), the through opening (9) extending from the first end side (7) up to the second end side (8) for the passage of the guide shaft (3), characterized by a sound-insulating device (6, 20), the sound-insulating device (6, 20) comprising an insulator (11) for sound insulation arranged on one of the two end sides (7, 8) of the linear bearing (5).

2. Linear bearing unit (2, 19) according to claim 1, characterized in that the linear bearing (5) is designed as a linear ball bearing.

3. Linear bearing unit (2, 19) according to claim 1 or 2, characterized in that the spacer (11) has a through-opening (9) for guiding the shaft (3) through, and the diameter of the through-opening (9) of the spacer (11) is at most the diameter of the through-opening (9) of the linear bearing (5).

4. Linear bearing unit (2, 19) according to one of the preceding claims, characterized in that the insulating body (11) is designed in the shape of a ring, in particular with a rectangular or square cross-sectional shape.

5. Linear bearing unit (2, 19) according to one of the preceding claims, characterized in that the insulating body (11) consists of or comprises a foam material.

6. Linear bearing unit (2, 19) according to one of the preceding claims, characterized in that the insulator (11) is impregnated with a lubricant for lubricating the linear bearing (5).

7. Linear bearing unit (2) according to one of the preceding claims, characterized in that the sound insulation device (6) comprises an isolator housing (10), in particular an annular isolator housing (10), the isolator (11) being arranged within the isolator housing (10), and the isolator housing (10) having a through-opening (9) for guiding the shaft (3) through.

8. Linear bearing unit (19) according to one of the preceding claims, characterized in that the sound-insulating device (20) has a sound-insulating housing (21), in particular a two-part sound-insulating housing (21), in which sound-insulating housing (21) the linear bearing (5) and the insulating body (11) are arranged, and the sound-insulating housing (21) has a through-opening (9) for guiding the shaft (3) through, wherein the sound-insulating housing (21) is preferably a plastic housing.

9. Linear bearing unit (19) according to claim 8, characterized by a force transmission element (24) arranged between the sound-proof housing (21) and the linear bearing (5), wherein the force transmission element (24) surrounds a sub-part of the linear bearing (5).

10. Linear bearing unit (2) according to one of the preceding claims, characterized by a bearing housing (4), in which bearing housing (4) the linear bearing (5) and the sound insulation means (6) are arranged, and which bearing housing (4) has a through-opening (9) for guiding the shaft (3) through, wherein the bearing housing (4) is preferably a metallic housing.

11. Linear bearing unit (2, 19) according to one of the preceding claims, characterized in that the sound insulation means (6, 20) comprises a further insulating body (11) for sound insulation, which further insulating body (11) has a through-opening (9) for guiding the shaft (3) through, wherein one of the two insulating bodies (11) of the sound insulation means (6, 20) is arranged on the first end side (7) of the linear bearing (5) and the other of the two insulating bodies (11) of the sound insulation means (6, 20) is arranged on the second end side (8) of the linear bearing (5).

12. A linear bearing system (1, 18) comprising a linear bearing unit (2, 19) according to any one of the preceding claims and a shaft (3) guided through the linear bearing unit (2, 19), wherein the insulator (11) of the sound insulation device (6, 20) of the linear bearing unit (2, 19) surrounds the sub-part of the shaft (3) in a gas-tight manner on the circumference of the sub-part of the shaft (3).

13. Linear bearing system (1, 18) according to claim 12, characterized in that the thickness of the insulating body (11) of the sound-insulating device (6, 20) in the axial direction of the shaft (3) corresponds to at least 5% of the diameter of the shaft (3), preferably to at least 10% of the diameter of the shaft (3).

14. Linear bearing system (1, 18) according to claim 12 or 13, characterized in that the thickness of the insulating body (11) of the sound-insulating device (6, 20) in the radial direction of the shaft (3) corresponds to at least 5% of the diameter of the shaft (3), preferably to at least 10% of the diameter of the shaft (3).

15. Exercise equipment (25), in particular leg press, with at least one linear bearing unit (2, 19) according to one of claims 1 to 11 or with at least one linear bearing system (1, 18) according to one of claims 13 to 14.