balance shaft

Abstract

Balance shaft (1) for compensating inertial forces and / or inertial moments, in particular for compensating inertial forces and / or inertial moments of a reciprocating internal combustion engine, comprising: - an elongated base body (2); - at least one bearing area (10) formed on the base body (2), over which the balance shaft (1) can be mounted for rotating support about a rotation axis (R) by means of a bearing; and - a first unbalanced section (11) and a second unbalanced section (12), -- whose centers of mass are each located outside the rotation axis (R) of the balance shaft (1) and -- which are formed on the base body (2) on opposite sides of the bearing area (10) as seen in the longitudinal direction of the base body; wherein, during operation of the balance shaft (10), the first unbalance section (11) is tilted relative to the rotation axis (R) by a first angle (W1) and the second unbalance section (12) is tilted relative to the rotation axis (R) by a second angle (W2), wherein the balance shaft (1) is designed such that the first unbalanced section (11) and the second unbalanced section (12) tilt to the same side; wherein the balance shaft (1) has a further bearing area (20) over which the balance shaft (1) can be mounted for rotating support about the rotation axis (R) by means of a further bearing; further comprising, - a third unbalance section (21) and a fourth unbalance section (22), -- whose centers of mass are each located outside the rotation axis (R) of the balance shaft (1) and -- which are formed on the base body (2) on opposite sides of the further bearing area (20) as seen in the longitudinal direction of the base body (2), wherein during operation of the balance shaft (1) the third unbalance section (21) is tilted relative to the rotation axis (R) by a third angle (W3) and the fourth unbalance section (22) is tilted relative to the rotation axis (R) by a fourth angle (W4) wherein the balance shaft (1) is designed such that the third unbalanced section (21) and the fourth unbalanced section (22) tilt to the same side, characterized in that the second angle (W2) is greater than the first angle (W1) and the third angle (W3) is greater than the fourth angle (W4).

Description

[0001] The present invention relates to a balance shaft and a method for producing a balance shaft.

[0002] Balance shafts are well known in the art, for example from DE 10 2015 218 277 A1. Such balance shafts serve to balance the inertial forces and / or inertial moments caused by a crankshaft during its rotation in an internal combustion engine. This reduces operating noise and vibrations in the internal combustion engine. To balance the inertial forces, unbalanced sections are specifically formed on an elongated base body. These unbalanced sections provide compensating counterforces to the forces caused by a crankshaft when the balance shaft rotates. The balance shafts are driven synchronously with the crankshaft, for example via gears or belts. Depending on the design of the internal combustion engine, one or two balance shafts are used, or the balance shaft is driven at the same speed or twice the speed of the crankshaft.

[0003] Due to the forces that occur during operation, i.e. when the balancer shaft rotates around a rotational axis, the balancer shaft deforms or bends. This bending typically leads to tilting of a bearing area via which the balancer shaft is mounted so that it rotates around the axis of rotation. As a result, the balancer shaft and the bearing in the bearing area are subjected to uneven loads. If the balancer shaft is driven via a gear, this is also tilted relative to the axis of rotation, so that the teeth of the gear are subjected to uneven loads during operation. As a result of the additional loads, increased wear is to be expected and complex remachining is necessary, for example on the teeth of a drive gear, during production of the balancer shaft.

[0004] It is therefore an object of the present invention to provide a balance shaft with which a load and thus wear for the balance shaft and the parts driving and / or supporting the balance shaft can be reduced.

[0005] This object is achieved by a balance shaft according to claim 1, as well as a method for producing a balance shaft according to claim 12. Further advantages and features of the invention emerge from the subclaims as well as the description and the attached figures.

[0006] According to the invention, a balance shaft is provided for compensating inertial forces and / or inertial moments, in particular for compensating inertial forces and / or inertial moments of a reciprocating piston internal combustion engine, comprising: - an elongated body; - at least one bearing area formed on the base body, over which the balance shaft can be mounted for rotating support about a rotation axis by means of a bearing; and - a first unbalance section and a second unbalance section, -- whose centers of mass are located outside the rotational axis of the balance shaft and -- which are formed on the base body on opposite sides of the bearing area, viewed in the longitudinal direction of the base body;wherein, during operation of the balance shaft, the first unbalanced section is tilted by a first angle relative to the axis of rotation and the second unbalanced section is tilted by a second angle relative to the axis of rotation, wherein the balance shaft is designed such that the first unbalanced section and the second unbalanced section tilt to the same side.

[0007] Compared to the prior art, the design according to the invention proves to be advantageous because the identically directed tilting of the first unbalanced section and the second unbalanced section in the bearing area creates a type of apex that can counteract tilting of the bearing area. By bending to the same side, the first unbalanced section and the second unbalanced section act in opposite directions on the bearing area, whereby tilting of the bearing area can be reduced. In contrast, in the balance shafts known from the prior art, the first unbalanced section and the second unbalanced section bend or tilt in opposite directions away from the axis of rotation. As a result, the first and second unbalanced sections act in the same direction on the bearing area, and the bearing area of the balance shafts from the prior art is rotated or tilted along with them.

[0008] As a result of the reduced tilting of the bearing area, more uniform contact can be achieved between the bearing and the bearing area, which has a positive effect on the wear of the balance shaft and bearing, thus extending their service life. In the case of a gear for transmitting drive force to the balance shaft, the claimed design also reduces tilting of the gear. As a result, the gear teeth remain aligned in such a way that optimal power transmission is possible and load can be reduced. In particular, it is conceivable that complex post-treatment steps, such as hardening or coating, can be omitted during gear manufacturing. This also advantageously reduces manufacturing costs.

[0009] To ensure that the first and second imbalance sections rotate in the same direction, the balance shaft is specifically shaped or designed accordingly. For example, the balance shaft has a targeted material weakening in the bearing area, such as a notch. Furthermore, a rib structure extending along the longitudinal direction of the balance shaft is conceivable. This rib structure, which is essentially intended for stiffening, can also be modulated in the axial direction or longitudinal direction of the base body, for example, by selectively tapering or thickening. This allows the stiffness to be adjusted locally on the balance shaft.Furthermore, it is conceivable that the size, shape (for example, viewed in the radial or axial direction) of the first imbalance section and / or the second imbalance section are designed such that the first imbalance section and the second imbalance section tilt to the same side, viewed from the axis of rotation. Furthermore, it is conceivable that the location or position / distance relative to the bearing area or the length of the first imbalance section and / or the second imbalance section measured in the axial direction are adapted to cause a desired bending to the same side during operation. To determine the optimal design of the balance shaft that causes the desired tilting, a simulation is preferably carried out in which the main functionality of the balance shaft, namely to generate counter-torques to the mass moments of the crankshaft, is taken into account.

[0010] In particular, tilting occurring during operation is understood to mean bending or deformation that can be observed during rotation at a speed of more than 5,000 revolutions per minute, for example at 10,000 revolutions per minute. Furthermore, it is preferably provided that the orientation of the first unbalanced section and the orientation of the second unbalanced section are mirror-symmetrical to one another with respect to a mirror plane or plane of symmetry running perpendicular to the longitudinal direction of the balance shaft and through the bearing area. Tilting to the same side is also understood to mean a slightly twisted position of the first unbalanced section relative to the second unbalanced section. This means that, viewed in the direction of rotation, the first unbalanced section and the second unbalanced section can be twisted or rotated relative to one another by an angle of less than 40°, preferably less than 20°, and particularly preferably less than 10°.Particularly preferably, the first unbalanced section and the second unbalanced section are parallel to one another when viewed in the longitudinal direction, particularly preferably on a line.

[0011] According to a preferred embodiment of the present invention, it is provided that a difference between the first angle and the second angle, in particular their absolute values, is less than 0.8 mrad, preferably less than 0.5 mrad, and particularly preferably less than 0.25 mrad. By ensuring that the absolute values of the first angle and the second angle are as identical as possible, the bearing area can be aligned as horizontally as possible, thereby enabling the best possible contact with the bearing.

[0012] Preferably, the balance shaft has a further bearing area, over which the balance shaft can be mounted for rotating support about the rotation axis by means of this further bearing. For this purpose, the balance shaft comprises - a third unbalance section and a fourth unbalance section, -- whose centers of mass are located outside the rotational axis of the balance shaft and -- which are formed on the base body on opposite sides of the further bearing area, viewed in the longitudinal direction of the base body, wherein during operation of the balance shaft the third unbalance section is tilted by a third angle relative to the axis of rotation and the fourth unbalance section is tilted by a fourth angle relative to the axis of rotation, wherein the balance shaft is designed such that the third unbalance section and the fourth unbalance section tilt to the same side. Preferably, the first unbalance section, the second unbalance section, the third unbalance section and the fourth unbalance section are tilted, bent or twisted towards the same side. This results in an essentially M- or W-shaped course or an M- or W-shaped bending line for the balance shaft during operation.

[0013] The second unbalanced section and the third unbalanced section are preferably arranged together between the bearing area and the further bearing area. It is also conceivable for the second and third unbalanced sections to merge into one another or for an additional unbalanced section to be formed between the second and third unbalanced sections. Furthermore, it is conceivable for the second angle and the third angle or the first and fourth angles to be essentially identical. Alternatively, it is also conceivable for the individual angles to differ from one another. Furthermore, it is provided that the second angle and / or the third angle is greater than the first angle and / or the fourth angle. To ensure the gear is aligned as horizontally as possible, one advantageous embodiment provides for the fourth angle to be smaller than the first angle, the second angle and the third angle.It is also conceivable for the balance shaft to be designed such that the first imbalance section and / or the fourth imbalance section run essentially horizontally during operation. Furthermore, it is conceivable for a distance between the bearing area and the further bearing area to be adjusted to ensure tilting to the same side during operation.

[0014] In a further embodiment of the present invention, it is provided that the first angle, the second angle, the third angle and / or the fourth angle is less than 1.03 mrad, preferably less than 1.00 mrad and particularly preferably less than 0.7 mrad. In particular, in this way, a tilt of the first or fourth unbalanced section can be kept so small that a tilt of the gear which, viewed in the longitudinal direction, adjoins the first unbalanced section or the fourth unbalanced section, is less than 1.013, i.e. less than those tilts for the gear which are known from the prior art. The first angle, the second angle, the third angle and the fourth angle are determined in particular at maximum rotational load, preferably at a speed of substantially 10,000 revolutions per minute.

[0015] In a further embodiment of the present invention, the balance shaft is manufactured by means of primary forming, in particular forged or cast. This allows for a particularly stable balance shaft that can permanently withstand the loads encountered during operation.

[0016] Preferably, it is provided that essentially no material is provided in the region of the rotational axis of the balance shaft in the first unbalance section, the second unbalance section, the third unbalance section, and / or the fourth unbalance section. Furthermore, it is conceivable that essentially no material is provided in the region of the rotational axis of the balance shaft in the bearing area and / or further bearing area. These material reductions advantageously allow the weight of the balance shaft to be reduced. For example, the balance shaft comprises hollow areas for this purpose.

[0017] In a further embodiment, it is provided that a diameter of the first unbalanced section, the second unbalanced section, the third unbalanced section and / or the fourth unbalanced section, measured perpendicular to the longitudinal direction, is designed such that a race for its assembly can be pulled over one end of the balance shaft and moved up to the bearing area and / or further bearing area. A race is also to be understood, in particular, as an inner ring of a bearing. For example, the first unbalanced section is arranged between an end face of the balance shaft. If the first unbalanced section is dimensioned such that the inner diameter of the race or the inner ring of the bearing is larger than the unbalanced section at its widest point, the one-piece and closed race can be pulled over the end of the balance shaft, threaded over the first unbalanced section and moved up to the bearing area.Surprisingly, it has been found that such dimensioning is still possible even if the balance shaft is designed to tilt to the same side with the first unbalance section and the second unbalance section.

[0018] Preferably, the first unbalanced section and / or the second unbalanced section are adjacent to the bearing area, in particular directly adjacent. For example, collar elements for delimiting the bearing area are omitted, and the first unbalanced section and the second unbalanced section prevent axial displacement of the bearing. It is also conceivable that by tilting the first unbalanced section and the second unbalanced section to the same side, the bearing ring or the inner ring is clamped to the first unbalanced section and the second unbalanced section, which can assist in securing the race.

[0019] Furthermore, it is preferably provided that the balance shaft has a gear, in particular a gear made of two different materials. For example, the gear comprises a core region and an edge region, wherein the material of the core region differs from the material of the edge region. Such a hybrid gear allows, for example, a comparatively light metal to be used for the core region, whereby the overall weight of the balance shaft can be advantageously reduced. It is conceivable that, due to the reduced tilting and thus the reduced load on the gear, the proportion of the core region in the overall gear can be dimensioned larger.

[0020] Preferably, the base body is designed in one piece.

[0021] A further subject of the present invention is a method for producing a balance shaft for compensating inertial forces and / or mass moments, in particular for compensating inertial forces and / or mass moments of a reciprocating internal combustion engine, comprising: - an elongated body; - at least one bearing area formed on the base body, over which the balance shaft can be mounted for rotating support about a rotation axis by means of a bearing; and - a first unbalance section and a second unbalance section, -- whose centers of mass are located outside the rotational axis of the balance shaft and -- which are formed on the base body on opposite sides of the bearing area, viewed in the longitudinal direction of the base body;wherein, during operation of the balance shaft, the first unbalance section is tilted relative to the axis of rotation by a first angle and the second unbalance section is tilted relative to the axis of rotation by a second angle, comprising the steps: The balance shaft is designed such that the first unbalanced section and the second unbalanced section tilt to the same side during operation. All features and their advantages described for the balance shaft according to the invention can be applied analogously to the method according to the invention, and vice versa.

[0022] Preferably, the shape of the balance shaft is determined by simulation. In particular, it is provided that, in a preliminary step, simulations are carried out that, taking into account the primary function of the balance shaft—namely, compensating the forces emanating from the crankshaft—appropriately dimension the first unbalance section, the second unbalance section, the third unbalance section, and the fourth unbalance section for an M-shaped or W-shaped bending line.

[0023] Further advantages and features will become apparent from the following description of preferred embodiments of the subject matter according to the invention with reference to the accompanying figures. Individual features of the individual embodiments can be combined with one another within the scope of the invention.

[0024] It shows: Fig. 1: schematic representation of a balance shaft according to the state of the art and Fig. 2: schematic representation of a balance shaft according to a preferred embodiment of the present invention

[0025] In Fig. Figure 1 schematically illustrates a balance shaft 1 according to the prior art. Such balance shafts 1 serve, in particular, to balance inertial forces and / or inertial moments, in particular to balance inertial forces and / or inertial moments of a reciprocating piston internal combustion engine, in order to reduce operating noise and vibrations and thus increase driving comfort. For this purpose, unbalanced sections 11, 12, 21, 22 are specifically formed on the balance shaft 1, which generate inertial forces or inertial moments that counteract those of a crankshaft of the internal combustion engine. In the example shown in Fig. 1, the balance shaft 1 comprises an elongated base body 2, on which a first unbalanced section 11, a second unbalanced section 12, a third unbalanced section 21, and a fourth unbalanced section 22 are formed. A bearing region 10 is formed between the first unbalanced section 11 and the second unbalanced section 12, and a further bearing region 20 is formed between the third unbalanced section 21 and the fourth unbalanced section 22. The bearing region 10 and the further bearing region 20 are provided as contact regions, via which the balance shaft 1 can be mounted in rotation about a rotation axis R by means of a bearing (not shown here), for example a radial bearing such as a needle bearing.It is conceivable that the bearing areas are delimited in the axial direction by a first collar element and a second collar element in order to prevent axial displacement of the bearing, or the first unbalanced section 11 and the second unbalanced section 12 are directly adjacent to the bearing area 10 in order to prevent axial displacement of the bearing.

[0026] The balance shafts 1 are driven synchronously by the crankshaft via gears 30, chains, or toothed belts. Depending on the design of the internal combustion engine, one or two balance shafts 1 are usually used, running at one or two times the crankshaft speed.

[0027] The Fig. 1 further shows the balance shaft 1 in operation, ie in a state in which the balance shaft 1 rotates about the rotation axis R. For example, the balance shaft 1 is rotated at 5400 revolutions per minute. As a result of this rotation, bending occurs in the balance shaft due to the forces occurring during the rotation, ie a deformation along a bending line, which in the Fig. 1 are exaggerated for better understanding. The different shades of grey in the Fig. 1 and Fig. 2 indicate corresponding force curves or local loads in the balance shaft 1. In particular, the first unbalanced section 11, the second unbalanced section 12, the third unbalanced section 21 and the fourth unbalanced section 22 tilt relative to the rotation axis R. The first unbalanced section 11 and the second unbalanced section 12 tilt in opposite directions, i.e., to opposite sides, so that the bearing area arranged between the first unbalanced section 11 and the second unbalanced section 12 also tilts. As a result, the bearing area is tilted relative to its bearing, which supports the balance shaft, so that uniform contact between the bearing area 10 and the bearing cannot be ensured. The result is a higher load or increased wear on the system comprising the balance shaft 1 and the bearing. The same applies to the third unbalanced section 21 and the fourth unbalanced section 22 with the further bearing area 20.

[0028] In the Fig. 2 schematically shows a balance shaft 1 according to a preferred embodiment of the present invention. The balance shaft 1 in Fig. 2 also shows the situation that arises during operation of the balance shaft 1. It has been shown that the first unbalanced section 21 and / or the second unbalanced section 22 can be designed in such a way, particularly with regard to shape, size and / or bearings, that the first unbalanced section 11 and the second unbalanced section 12 tilt in the same direction or to the same side during operation. In the exemplary embodiment shown, the first unbalanced section 11 and the second unbalanced section 12 tilt downwards. As a result, the bearing area 30 between the first unbalanced section 11 and the second unbalanced section 12 tilts less, and a more even load on the balance shaft 1 and bearings can be realized, which has a beneficial effect on the service life of the balance shaft 1 and the bearings.The same can be achieved for the third unbalanced section 21 and the fourth unbalanced section 22, as well as the additional bearing area 20 located between them. In particular, a W-shaped profile or a W-shaped bending line is formed for the balance shaft 1. It has proven particularly advantageous that the targeted tilting of the individual unbalanced sections 11, 12, 21, 22 results in a gear at the end of the balance shaft being tilted less during operation. In particular, the fourth angle for the balance shaft is . Fig. 2 smaller than the fourth angle in the Fig. 1. Accordingly, the teeth of gear 30 are subjected to less stress. This eliminates the need for complex post-processing of the teeth, such as hardening or coating, during their production.

[0029] In order to achieve tilting of the first unbalanced section 11, the second unbalanced section 12, the third unbalanced section 21, and the fourth unbalanced section 22 in the same direction or to the same side, it is preferably provided that their shape and / or position is designed accordingly so that the desired tilting occurs during operation. In this case, it is conceivable that a distance between the bearing area 10 and the further bearing area 20 is taken into account, or a rib structure 15 that extends along the balance shaft over the first unbalanced section 11, the second unbalanced section 12, the third unbalanced section 21, and the fourth unbalanced section 22 is used. The rib structure 15 is preferably used for stiffening. By specifically modifying or varying the rib structure 15, for example, the local stiffness of the balance shaft 1 can be influenced.Furthermore, it is conceivable that the desired tilting can be achieved by a targeted increase in weight 21 in the first unbalance section 11.

[0030] Furthermore, it is provided that during operation the first unbalanced section 11 is tilted by a first angle W1, the second unbalanced section 12 by a second angle W2, the third unbalanced section 21 by a third angle W3 and the fourth unbalanced section 22 by a fourth angle W4 relative to the rotation axis R. In this case, it is particularly possible for the first angle W1, the second angle W2, the third angle W3 and the fourth angle W4 to be smaller than 1 mrad, for example a maximum of between 0.3 mrad and 1 mrad. It is also conceivable for the balance shaft to be designed such that the fourth angle W4 is smaller than the first angle W1, the second angle W2 and / or the third angle W3. This ensures that the tilting of the gear 30 is as small as possible. List of reference symbols: 1 balance shaft 4 End of the balance shaft 10 Storage area 11 first unbalance section 12 second unbalance section 15 Rib structure 20 additional storage areas 21 third unbalance section 22 fourth unbalance section 30 gear R Rotation matter QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2015 218 277 A1

[0002]

Claims

[1] Balance shaft (1) for compensating inertial forces and / or inertial moments, in particular for compensating inertial forces and / or inertial moments of a reciprocating internal combustion engine, comprising: - an elongated base body (2); - at least one bearing area (10) formed on the base body (2), over which the balance shaft (1) can be mounted for rotating support about a rotation axis (R) by means of a bearing; and - a first unbalanced section (11) and a second unbalanced section (12), -- whose centers of mass are each located outside the rotation axis (R) of the balance shaft (1) and -- which are formed on the base body (2) on opposite sides of the bearing area (10) as seen in the longitudinal direction of the base body; wherein, during operation of the balance shaft (10), the first unbalance section (11) is tilted relative to the rotation axis (R) by a first angle (W1) and the second unbalance section (12) is tilted relative to the rotation axis (R) by a second angle (W2), wherein the balance shaft (1) is designed such that the first unbalanced section (11) and the second unbalanced section (12) tilt to the same side; wherein the balance shaft (1) has a further bearing area (20) over which the balance shaft (1) can be mounted for rotating support about the rotation axis (R) by means of a further bearing; further comprising, - a third unbalance section (21) and a fourth unbalance section (22), -- whose centers of mass are each located outside the rotation axis (R) of the balance shaft (1) and -- which are formed on the base body (2) on opposite sides of the further bearing area (20) as seen in the longitudinal direction of the base body (2), wherein during operation of the balance shaft (1) the third unbalance section (21) is tilted relative to the rotation axis (R) by a third angle (W3) and the fourth unbalance section (22) is tilted relative to the rotation axis (R) by a fourth angle (W4) wherein the balance shaft (1) is designed such that the third unbalance section (21) and the fourth unbalance section (22) tilt to the same side, characterized by that the second angle (W2) is greater than the first angle (W1) and the third angle (W3) is greater than the fourth angle (W4). [2] Balance shaft (1) for compensating inertial forces and / or inertial moments, in particular for compensating inertial forces and / or inertial moments of a reciprocating internal combustion engine, comprising: - an elongated base body (2); - at least one bearing area (10) formed on the base body (2), over which the balance shaft (1) can be mounted for rotating support about a rotation axis (R) by means of a bearing; and - a first unbalanced section (11) and a second unbalanced section (12), -- whose centers of mass are each located outside the rotation axis (R) of the balance shaft (1) and -- which are formed on the base body (2) on opposite sides of the bearing area (10) as seen in the longitudinal direction of the base body; wherein, during operation of the balance shaft (10), the first unbalance section (11) is tilted relative to the rotation axis (R) by a first angle (W1) and the second unbalance section (12) is tilted relative to the rotation axis (R) by a second angle (W2), wherein the balance shaft (1) is designed such that the first unbalanced section (11) and the second unbalanced section (12) tilt to the same side; wherein the balance shaft (1) has a further bearing area (20) over which the balance shaft (1) can be mounted for rotating support about the rotation axis (R) by means of a further bearing; further comprising, - a third unbalance section (21) and a fourth unbalance section (22), -- whose centers of mass are each located outside the rotation axis (R) of the balance shaft (1) and -- which are formed on the base body (2) on opposite sides of the further bearing area (20) as seen in the longitudinal direction of the base body (2), wherein during operation of the balance shaft (1) the third unbalance section (21) is tilted relative to the rotation axis (R) by a third angle (W3) and the fourth unbalance section (22) is tilted relative to the rotation axis (R) by a fourth angle (W4) wherein the balance shaft (1) is designed such that the third unbalance section (21) and the fourth unbalance section (22) tilt to the same side, characterized by that the second angle (W2) and the third angle (W3) are larger than the first angle (W1) and the fourth angle (W4). [3] Balance shaft (1) according to one of the preceding claims, wherein a difference between the first angle (W1) and the second angle (W2) is less than 0.8 mrad, preferably less than 0.5 mrad and particularly preferably less than 0.25 mrad. [4] Balance shaft according to one of the preceding claims, wherein the first angle (W1), the second angle (W2), the third angle (W3) and / or the fourth angle (W4) is less than 1.03 mrad, preferably less than 1.00 mrad and particularly preferably less than 0.7 mrad. [5] Balance shaft (1) according to one of the preceding claims, wherein the balance shaft (1) is forged or cast. [6] Balance shaft (1) according to one of the preceding claims, wherein in the first unbalanced section (11), in the second unbalanced section (12), in the third unbalanced section (21) and / or in the fourth unbalanced section (22) substantially no material is provided in the region of the rotational axis (R) of the balance shaft (1). [7] Balance shaft (1) according to one of the preceding claims, wherein in the bearing region (10) and / or further bearing region (20) substantially no material is provided in the region of the rotational axis (R) of the balance shaft (1). [8] Balance shaft (1) according to one of the preceding claims, wherein a diameter of the first unbalanced section (11), the second unbalanced section (12), the third unbalanced section (21) and / or the fourth unbalanced section (22) measured perpendicular to the longitudinal direction of the balance shaft (1) is designed such that a race for its assembly can be pulled over one end (4) of the balance shaft (1) and can be displaced up to the bearing area (10) and / or further bearing area (20). [9] Balance shaft (1) according to one of the preceding claims, wherein - the first unbalance section (11) and / or the second unbalance section (12) to the bearing area (10) and / or - the third unbalance section (21) and / or the fourth unbalance section (22) adjoin the further bearing area (20). [10] Balance shaft (1) according to one of the preceding claims, wherein the balance shaft (1) has a gear (30), in particular a gear (30) made of two different materials. [11] Balance shaft (1) according to one of the preceding claims, wherein the base body (2) is designed in one piece.

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