may cause lateral forces in the x-direction.

FIG. 5 schematically shows a telescopic boom assembly 100 according to a further embodiment in a cross-sectional view along a y-z plane.

The telescopic boom assembly 100 shown in FIG. 5 may comprise a first boom segment 110 having at least one first wear pad assembly 10A mounted to a free end 112 of the first boom segment 110. Further, telescopic boom assembly 100 may comprise a second boom segment 120 having at least one second wear pad assembly 10B mounted to a sliding end 122 of the second boom segment 120. The second boom segment 120 may be configured to be slidable along the at least one first wear pad assembly 10A of the first boom segment 110. Additionally, the second boom segment 120 may comprise at least one third wear pad assembly 10C mounted to a free end 124 of the second boom segment 120 and a third boom segment 130 having at least one fourth wear pad assembly 10D mounted to a sliding end 132 of the third boom segment 130. The third boom segment 130 may be configured to be slidable along the at least one third wear pad assembly 10C of the second boom segment 110.

The embodiment shown in FIG. 5 may be based on, or fully incorporate, the embodiment shown in FIG. 3, yet with an additional, third boom segment 130. Accordingly, with respect to the wear pad assemblies 10A and 10B, the same principles defined in the context of FIG. 3 also apply for the additional wear pad assemblies 10C and 10D.

As shown in FIG. 5, at least one of the wear pad assemblies 10A, 10B may comprise a wear pad 10 having a base part 12 and a top layer part 14 configured to provide a wear-resistant, low friction sliding surface 16. The top layer part 14 may be configured to be releasably mounted to the base part.

The telescopic boom assembly 100 shown in FIG. 5 may comprise boom segments 110, 120, 130 having a rectangular cross-section. The wear pad assemblies 10A, 10B, 10C, 10D may comprise at least one wear pad 10 on each side of the corresponding boom segment 110, 120, 130. To further illustrate this, it is referred to FIG. 6 in combination with a section plane I-II provided in FIG. 5.

FIG. 6 schematically shows the telescopic boom assembly 100 of FIG. 5 in a cross-sectional view along a x-z plane. More specifically, FIG. 4 schematically shows the telescopic boom assembly 100 seen from along the section plane I-II of FIG. 5, yet in a configuration where the third boom segment 130 is retracted such that its sliding end 132 is also positioned within the section plane I-II.

The wear pads 10i, 10ii shown in FIG. 6 belong to the second wear pad assembly 10B and the fourth wear pad assembly 10D of the telescopic boom assembly 100 shown in FIG. 3. The outer rectangle represents the first boom segment 110. The middle rectangle represents the sliding end 122 of the second boom segment 120 and the inner rectangle represents the sliding end 132 of the third boom segment 130 of the telescopic boom assembly 100. Correspondingly, the wear pads 10 belonging to the second wear pad assembly 10B in cross-section I-II are all mounted to the sliding end 122 of the second boom segment 120. Likewise, the wear pads 10i, 10ii belonging to the fourth wear pad assembly 10D in cross-section I-II are all mounted to the sliding end 132 of the third boom segment 130 of the telescopic boom assembly 100.

To this end, the wear pad assemblies 10A, 10B, 10C, 10D may comprise at least one wear pad 10 on each side of the corresponding boom segment 110, 120, 130. More specifically, the wear pad assemblies 10A, 10B, 10C, 10D may comprise at least two wear pads 10i, 10ii respectively, on each side of the corresponding boom segment 110, 120, 130, wherein the large wear pads 10ii provided on the shorter sides may comprise a base part 12 larger than a base part 12 of the short wear pads 10i provided on the larger sides of a rectangular cross-section.

More specifically, the sliding end 122 of the second boom segment 120 may comprise four large wear pads 10, two large wear pads 10ii on each of its upper and lower sides and, in addition thereto, four small wear pads 10i, two on each lateral sides of the sliding end 122 of the second boom segment 120. Thereby, the loads acting on the telescopic boom assembly 100 may be distributed adequately. Likewise, the sliding end 132 of the third boom segment 130 may comprise four large wear pads 10ii, two on each of its upper and lower sides and, in addition thereto, four small wear pads 10i, two on each of its lateral sides of the sliding end 132 of the third boom segment 130. Thereby, the loads acting on the telescopic boom assembly 100 may be distributed adequately.

FIG. 7 schematically shows a work machine 300 comprising a telescopic boom according to the embodiment shown in FIGS. 5 and 6. The telescopic boom assembly 100 shown in FIG. 7 comprises a first boom segment 110, a second boom segment 120 and a third boom segment 130.

It will be obvious for a person skilled in the art that these embodiments and items only depict examples of a plurality of possibilities. Hence, the embodiments shown here should not be understood to form a limitation of these features and configurations. Any possible combination and configuration of the described features can be chosen according to the scope of the invention.

This is in particular the case with respect to the following optional features which may be combined with some or all embodiments, items and all features mentioned before in any technically feasible combination. As an example, a wear pad may have more than one base parts and/or top layer parts. Each telescopic boom assembly may have more than a first, a second and a third boom segment and there may be more or less wear pads provided within a telescopic boom assembly.

A wear pad for a telescopic boom of a work machine may be provided, comprising a base part configured to be fixedly mounted to the telescopic boom and a top layer part configured to provide a wear resistant, low friction sliding surface. The top layer part is configured to be releasably mounted to the base part. Thereby, most of the wear pad may be provided in the shape of a base part wherein only a top layer part is configured to provide a wear resistant, low friction sliding surface. For example, the top layer part may comprise wear resistant, low friction material. Since such material is only needed for the top layer part, high-grade materials may be utilized.

By providing the top layer such that it is configured to be releasably mounted to the base part allows a simplified maintenance of a wear pad, since no manual work at the surrounding structure is required. Instead, the top layer part may simply be taken of the base part and be replaced by a new top layer part.

According to the present disclosure, releasably mounted may refer to a mount which is configured such that under normal operation of a telescopic boom assembly or a work machine, unintentional disengagement of the top layer part from the base part can be excluded. The expression releasably mounted may further refer to a mount which may be released manually or by using tools. Preferably, the expression releasably mounted may refer to a mount that allows releasing the top layer part from the base part without destroying the top layer part and/or the base part.

By comprising a wear pad having a base part and a top layer part configured to provide a wear resistant, low friction sliding surface, wherein the top layer part is configured to be releasably mounted to the base part, a simple, cost-effective, wear resistant wear pad for a telescopic boom of a work machine having only limited spatial boom segment offset and an improved maintenance handling.

By this, the available margin for erosion of the wear pad, also called erosion depth, may be restricted to the available thickness of the top layer part or a part of the thickness of the top layer part. At the same time, the remaining thickness of the wear pad may be configured such that it is optimized to support the top layer part and to be fixedly mounted the base part to the telescopic boom. Thereby, a more rigid, reliable and safe positioning of telescopic boom segments may be provided.

In a further development, the sliding surface may be equal to a surface area confined by an outer perimeter of the top layer part. According to the present disclosure, the outer perimeter of the top layer part may be the outer boundary, or outer circumference, of the top layer part in a plane substantially parallel to the sliding plane. By providing a wear pad having a sliding surface equal to a surface area confined by an outer perimeter of the top layer part, the sliding surface can be maximized. Thereby, a substantially full-surface contacting sliding surface may be provided. In other words, the surface area covered by the wear pad can be maximized, thereby increasing the effectiveness of a wear pad. As an example, the pressure on a wear pad for a given force acting on sliding surface of a wear pad may be reduced.

In a further development, the top layer part may be configured such that edges extending perpendicular to a sliding direction may be tapered. Thereby, the initial friction can be reduced. Further, excessive wearing or tearing of edges extending perpendicular to a sliding direction can thereby be avoided or reduced.

According to the present disclosure, the top layer part may comprise a nylon, polytetrafluoroethylene, graphite, molybdenum disulfide and/or a metal. Thereby, the top layer part may be configured to provide a wear-resistant, low friction sliding surface. Polytetrafluoroethylene (PTFE), graphite, molybdenum disulfide and metal have the advantage of high temperature resistance. Thereby, wear can be minimized even at elevated operation temperatures and/or at high loads acting on the sliding surface. In general, the top layer part may comprise a material having sufficient compressive strength to withstand loads but also offers a good compressive strength and a low friction coefficient in order to allow transverse sliding action of a boom segment sliding along the sliding surface.

In a preferred development, the top layer part may comprise a combination of a nylon polymer embedded with a lubricant. Thereby, the compressive strength of nylon may be combined with low friction efficient of the lubricant.

In a preferred embodiment, the top layer part may comprise a top layer plate and a multitude of plugs, extending at least partially into the top layer plate. Thereby, a composite component of different materials may be attained. As an example, the top layer part may consist of the top layer plate further multitude of plugs may reach inside of the top layer plate and/or may protrude slightly therefrom. By this, advantages of different physical material properties may be combined effectively.

According to a preferred embodiment, the top layer plate may comprise bronze, wherein the multitude of plugs a comprise graphite. By comprising a composite of bronze and graphite, graphite particles may serve as smearing substance for the bronze top layer plate, thereby increasing the overall wear assistance and decreasing the friction coefficient of the sliding surface of the wear pad.

In a further development, the base part may comprise a ferrous metal, in particular a steel or a steel alloy. By providing the base part such that it comprises a ferrous metal, a cost-effective, rigid support for the top layer part may be provided. Thereby, the base part may comprise a material of high compressive strength. Further, the base part may be mounted conveniently to a surrounding structure. Preferably, the base part may be configured to be fixedly mounted to the telescopic boom by a welded joint. To this end, the base part may have a material composition which is weldable to a telescopic boom segment.

In a preferred embodiment, the wear pad may comprise a base part comprising at least one threaded recess in at least one fastening screw configured to engage the at least one threaded recess to fasten the base part to a telescopic boom. Thereby, the base part may be configured to be fixedly mounted to the telescopic boom by a threaded joint.

In a preferred development, the wear pad may further comprise at least one top layer part fastening means, preferably wherein the top layer part fastening means comprises a dowel pin. Thereby, the top layer part may be configured to be releasably mounted to the base part. In particular, the top layer fastening means may comprise two dowel pins which may partly extend into the base part and partly extend into the top layer part. Thereby, releasing and mounting the top layer part from and to the base part may be achieved by readily available tools. To this end, maintenance of the wear pad may be possible even under difficult circumstances. By providing two dowel pins, the erosion depth of the top layer part may be reduced further.

In a preferred development, the top layer part may have a thickness of 10 mm and may further be configured such that it is to be replaced after a wear greater or equal than 3-5 mm, wherein the dowel pins may each have a diameter of 2 mm and a length of 8 mm. Thereby, a gap of 6 mm between the sliding surface 16 and the dowel pins may be provided as erosion thickness.

According to a further development, the two dowel pins may for example be provided along a longitudinal middle axis of the wear resistant, low friction slide surface. Thereby, forces acting on the wear-resistant, low friction sliding surface may be dissipated into the base part partly by the dowel pins equally.

In a further development, the top layer part may have a thickness of 10 mm may further be configured such that it is to be replaced after a wear greater or equal than 3-5 mm. Thereby, it can be avoided that the wear reaches an extent which may be detrimental to a spatial boom segment orientation.

According to a further development, the top layer part may have a thickness of 10 mm may further be configured such that it is to be replaced after a wear greater or equal than 3-5 mm, wherein the dowel pins may each have a diameter of 2 mm and a length of 8 mm. Thereby, a gap of 6 mm between the sliding surface and the dowel pin may be provided as erosion thickness.