CN117698340A - Advancing wheel and intelligent courtyard nursing equipment - Google Patents

Abstract

The embodiment of the application provides a wheel and intelligent courtyard nursing equipment advance, advance the wheel and include: a tire; a plurality of gear teeth disposed on a tread of the tire; the tire comprises a tire body, a tire tread, a plurality of gear teeth, a tire cover and a tire, wherein the gear teeth are arranged in rows along the circumferential direction of the tire, at least three rows of gear teeth are arranged on the tire tread, the gear teeth of different rows are arranged in a staggered manner in the direction parallel to the axis of the tire, and the gear teeth comprise at least two gear teeth with different hardness. In the technical scheme of this embodiment, the staggered arrangement is arranged the teeth of a cogwheel in row on the tread, and the teeth of a cogwheel include the teeth of a cogwheel of at least two kinds of hardness, and the great teeth of a cogwheel of hardness have higher ground force of grabbing on soft ground, and the softer teeth of a cogwheel of hardness have higher ground force of grabbing on hard ground to make the wheel of marcing all have higher ground force of grabbing on the ground of multiple texture, advancing ability is better.

Description

Advancing wheel and intelligent courtyard nursing equipment

Technical Field

The application relates to the field of electrical equipment, in particular to a traveling wheel and intelligent courtyard nursing equipment.

Background

With the development and progress of technology, more and more work is replaced by machines. When maintaining the courtyard, the user can accomplish various maintenance works such as mowing, cleaning weed defoliation, fertilizing, sprinkling and the like through various intelligent devices.

However, different courtyard road conditions are different, and not only a large-area grassland, but also stone slab roads, stone roads, mud lands, sand lands and the like can be arranged in the courtyard. The travelling wheel on the existing intelligent courtyard maintenance equipment cannot adapt to various road condition environments, so that the problems of slipping, descending of climbing capacity and the like are easy to occur, and the problems of being clamped when the intelligent courtyard maintenance equipment passes through a ditch are also easy to occur.

Disclosure of Invention

In view of the foregoing, the present application has been directed to a travelling wheel and intelligent yard care apparatus that address, or at least partially address, the foregoing.

In one embodiment of the present application, there is provided a travel wheel comprising:

a tire;

a plurality of radial teeth arranged in rows along a circumferential direction of the tire such that there are a plurality of rows of radial teeth on a tread of the tire;

wherein the radial teeth of different rows are staggered with respect to each other in a direction parallel to the axis of the tire, and the plurality of radial teeth comprises radial teeth of at least two different hardness.

In another embodiment of the present application, there is also provided an intelligent yard care appliance, including an appliance body and the travelling wheel described above;

the travelling wheel is mounted on the equipment body.

In the technical scheme of this application embodiment, radial teeth of staggered arrangement into the row on the tread, and radial teeth include the radial teeth of at least two kinds of hardness, and the great radial teeth of hardness have higher ground force of grabbing on grassland, mud ground, sand ground, and the softer radial teeth of hardness have higher ground force of grabbing on stone road, slabstone road to make the wheel of marcing all have higher ground force of grabbing on the ground of multiple texture, the ability of marcing is better, and the wheel of marcing is difficult to skid. In addition, radial teeth which are staggered in rows on the tread have better mud and water drainage performance.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, a brief description will be given below of the drawings that are needed in the embodiments or the prior art descriptions, and it is obvious that the drawings in the following description are some embodiments of the present application, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a perspective view of a travel wheel provided in an embodiment of the present application;

FIG. 2 is a perspective view of another travel wheel provided in an embodiment of the present application;

FIG. 3 is a partial view of area A of FIG. 2;

fig. 4 is a perspective view of an intelligent yard care device according to an embodiment of the present application.

Detailed Description

In order to enable those skilled in the art to better understand the present application, the following description will make clear and complete descriptions of the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application.

The embodiments described herein are intended to be merely some, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments herein without making any inventive effort, are intended to be within the scope of the present application. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. By "substantially" is meant that within an acceptable error range, a person skilled in the art is able to solve the technical problem within a certain error range, substantially achieving the technical effect. In addition, in the embodiments of the present application, plural means two or more. Those skilled in the art may combine and combine the features of the different embodiments or examples described in this specification and of the different embodiments or examples without contradiction. The terms "first," "second," and the like herein are used for distinguishing between different directions, structures, elements, etc., and not for describing a sequential order.

Fig. 1 is a perspective view of a traveling wheel according to an embodiment of the present application, and fig. 2 is a perspective view of another traveling wheel according to an embodiment of the present application. Referring to fig. 1 and 2, in one embodiment of the present application, a running wheel is provided that includes a tire 1 and a plurality of radial teeth 3, the plurality of radial teeth 3 being disposed on a tread 2 of the tire 1. The plurality of radial teeth 3 are arranged in rows in the circumferential direction of the tire 1 such that there are a plurality of rows of radial teeth 3 on the tread of the tire 1. The center of rotation department of tire 1 is equipped with connection structure 4, and connection structure 4 is used for being connected with intelligent courtyard nursing equipment. The connecting structure 4 may be a connecting hole or a connecting shaft protruding from the side of the tire 1. In the technical scheme provided by the application. The tire 1 has various structures, for example, the tire 1 has a cylindrical structure, and the tread 2 on the tire 1 has a cylindrical side surface. Also for example, the tire 1 has a tapered structure, and the tread 2 of the tire 1 has an arcuate cross-sectional profile. For another example, the tire 1 has a truncated cone-shaped structure, and the tread 2 has a trapezoidal cross-sectional profile. The following describes the tire 1 in detail by taking a cylindrical structure as an example.

Referring to fig. 1 and 2, a plurality of radial teeth 3 are arranged in rows along the circumferential direction of the tire 1, at least three rows of radial teeth 3 (for example, a first row 31, a second row 32 and a third row 33 in fig. 1) are provided on the tread 2, the hardness of the radial teeth of the outer row (for example, the first row 31 and the third row 33 in fig. 1) of the tread is greater than the hardness of the radial teeth of the inner row (for example, the second row 32 in fig. 1), and the radial teeth 3 of different rows are staggered with each other in the axial direction parallel to the tire 1 (the thickness direction of the tire 1). The above-mentioned row may be regarded as a ring-shaped ring around the tread 2, the tread 2 being provided with a plurality of radial teeth 3, the radial teeth 3 on different rings being arranged offset in a direction parallel to the axis of the tyre 1, it being understood that the radial teeth 3 on different rings are not arranged in a row in the direction of the axis of the tyre 1. Along the axial direction of the tire 1, radial teeth 3 on the middle row are positioned between two rows of radial teeth 3 on the outer side of the tread 2, and gaps are arranged between adjacent radial teeth 3. A clearance is provided between adjacent radial teeth 3, which is understood to mean a clearance between the roots of the adjacent radial teeth 3. In addition, along the circumferential direction of the tire 1, the radial teeth 3 on different rows are offset from each other, and the offset radial teeth 3 not only can increase the grip force of the running wheel, but also can disperse the pressure on different radial teeth 3, so as to prevent the positions of a plurality of radial teeth 3 from being concentrated relatively and crush the ground.

In addition, the plurality of radial teeth 3 comprises at least two radial teeth 3 of different hardness. The stiffer radial teeth 3 may run on the travelling wheel to a softer ground, providing a greater grip for the travelling wheel, e.g. soft grass, muddy mud, loose sand etc. While the softer radial teeth 3 may provide greater grip for the running wheel as it runs onto harder ground. Such as a hard-textured slate floor, a rough stone floor, a concrete floor, etc. The radial teeth 3 with different hardness are arranged on the tread 2 in a staggered way, so that the travelling capability of the travelling wheel at the junction of different road conditions can be improved. For example, when the travelling wheel travels from the grass to the slate, the softer radial teeth 3 may timely contact the edge of the slate as the travelling wheel passes over the edge of the slate to provide a greater grip. The staggered arrangement is such that the softer radial teeth 3 are not blocked by the harder radial teeth 3 and do not touch the edges of the stone slab.

In the technical scheme that this application provided, set up radial tooth 3 of different hardness crisscross on tread 2, can effectively improve the wheel of marcing and grasp the land fertility on various complicated road conditions, the trafficability characteristic of the wheel of marcing is better. The courtyard nursing equipment provided with the travelling wheels can not cause the problems of slipping, insufficient climbing capacity, clamping when passing a ditch and the like when running in courtyards.

In addition, on the ground with hard texture, the radial teeth 3 with softer hardness provide main ground grabbing force, so that the impact force on the hard ground of the travelling wheel can be effectively reduced, the wear rate of the travelling wheel is reduced, and the service life of the travelling wheel is prolonged.

Referring to fig. 1, in one embodiment provided herein, tread 2 includes three rows of radial teeth 3 thereon, and the plurality of radial teeth 3 in the middle row (second row 32) have a hardness less than the hardness of the two rows of radial teeth 3 on either side of tread 2. Specifically, three rows of radial teeth 3 are arranged on the tread 2, the hardness of the outer two rows of radial teeth is greater than that of the middle row of radial teeth, and the hardness of the outer two rows of radial teeth is the same. The hardness of the radial teeth 3 of the two rows (first row 31 and third row 33) near the edges of the tyre 1 is greater, while the hardness of the radial teeth 3 of the row (second row 32) in between the two rows of radial teeth 3 is smaller. The number of radial teeth 3 on each row is the same, and the width of the radial teeth 3 with higher hardness is larger than the width of the radial teeth 3 with lower hardness. The radial teeth 3 with high hardness are arranged on the edge side of the tire 1, so that the supporting force of the running wheel is more stable, and the running wheel is not easy to incline.

Referring to fig. 1 and 2, in one embodiment provided in the present application, a first gap is provided between two adjacent radial teeth 3 in the same row, and the radial teeth 3 have a size in the circumferential direction of the tire 1 that is 0.5 to 3 times the first gap. It is understood that the spacing between adjacent radial teeth 3 is a first clearance and the length of the roots of the radial teeth 3 is 0.5 to 3 times the first clearance.

Further, in one embodiment provided in the present application, the radial teeth of the plurality of rows of radial teeth 3 have the same radial tooth structure, and the second gaps are formed between two adjacent rows, and the radial teeth 3 have a size 1 to 3 times the size of the second gaps along the wheel axis direction. Specifically, in the width direction of the tread 2, the pitch between the roots of the adjacent rows of radial teeth 3 is the second clearance, and the width of the roots of the radial teeth 3 is 1 to 3 times the second clearance.

In one embodiment provided herein, the plurality of radial teeth 3 in each row of radial teeth are identical in structure, with the different rows of radial teeth 3 being different in structure. The configuration of the radial teeth 3 is reliably understood as the shape of the radial teeth 3. For example, referring to fig. 1, the radial teeth 3 on the first row are all the same in shape and hardness as the radial teeth 3 having the harder hardness, while the radial teeth 3 on the second row are all the same in shape and hardness as the radial teeth 3 having the softer hardness. In another embodiment provided herein, the plurality of radial teeth 3 in each row may further comprise at least two configurations of radial teeth 3, e.g., a prismatic table configuration, a pyramidal configuration, a square block configuration, etc. Referring to fig. 2, the radial teeth 3 on the first row 31 comprise prismatic-shaped-frustum-shaped radial teeth 3 and conical-shaped radial teeth 3, and the radial teeth 3 of two different structures are arranged in a mutually crossing manner. While the radial teeth 3 on the second row 32 are all radial teeth 3 of conical configuration and are of the same configuration as the radial teeth 3 of the cones on the first row 31.

In one embodiment provided in the present application, the multiple rows of radial teeth 3 include at least one row of multiple structural teeth, where the multiple structural teeth are rows of teeth including at least two structural radial teeth, for example, referring to fig. 2, three rows of teeth, and two outer rows of teeth (first row 31 and third row 33) include two structural radial teeth, which may be the same or different. For another example, a running wheel has only two rows of radial teeth 2 on its tread, the two rows of radial teeth 3 being staggered, and each row of teeth comprising at least two structural radial teeth 3. In addition, the multiple rows of radial teeth 3 further include at least one row of single-structure teeth, and with continued reference to fig. 2, three rows of teeth, two rows (first row 31 and third row 33) on the outer side of the tread 2 are multiple-structure teeth rows, and the middle row (second row 32) is a single-structure teeth row, and the multiple radial teeth 3 of the middle row are identical in structure and are all conical.

In the technical solution provided in the present application, the number of the plurality of radial teeth 3 of different rows may be the same or different. The number of radial teeth 3 on each row is 15-45. For example, referring to fig. 1, the tread 2 is provided with three rows of radial teeth 3, and the number of radial teeth 3 on each row is the same. As another example, referring to fig. 2, tread 2 is also provided with three rows of radial teeth 3, the number of radial teeth 3 on first row 31 being the same as the number of radial teeth 3 on third row 33, and the number of radial teeth 3 on first row 31 being greater than the number of radial teeth 3 on second row 32. The number of radial teeth 3 on the second row 32 is half the number of radial teeth 3 of the first row 31. The radial teeth 3 of the same structure on different rows are located on the same diagonal line (as in diagonal line a in fig. 2). In addition, the number of radial teeth 3 of the three rows on the tread 2 may be different, the number of radial teeth 3 being the greatest on the row (first row 31) close to the outside of the tyre 1.

Further, when the plurality of radial teeth 3 on a row include two kinds of radial teeth 3, the radial teeth 3 of different structures are arranged at intervals. Referring to fig. 2, the plurality of radial teeth 3 on the first row 31 of the tread 2 comprises two structures, a gap being provided between the radial teeth 3 and the radial teeth 3, the width of the gap being greater than half the width of either radial tooth 3.

In order to obtain sufficient grip of the running wheel on different road conditions, the height of the radial teeth 3 and/or the hardness of the radial teeth 3 are different from one structure on the tread 2. In particular, the radial teeth 3 of different configurations on the tread 2 differ in height or hardness. For example, referring to fig. 2, the radial teeth 3 of two different configurations on the first row 31 of the tread 2 are different in height, but the same in hardness. In another embodiment, the radial teeth 3 of the cones in the first row 31 and the radial teeth 3 of the cones in the second row 32 are the same height but have different hardness. Alternatively, the radial teeth 3 of the prismatic table on the first row 31 of the tread 2 are different in height and in hardness from the radial teeth 3 of the conical body on the second row 32.

Referring to fig. 1, in one embodiment provided in the present application, the tip of the radial teeth 3 is provided with a pattern, and the patterns on the radial teeth 3 of different structures are different. Specifically, the pattern of the tips of the radial teeth 3 on the first row 31 on the tread 2 is a convex pattern, while the pattern of the tips of the radial teeth 3 on the second row 32 is a concave pattern. When the travelling wheel travels over a thick grass, the raised pattern on the radial teeth 3 can be inserted as far as possible into the earth of the ground, so that a sufficient grip is obtained. When the travelling wheel runs on the stone slab road, concave patterns on the radial teeth 3 are easier to deform, so that the contact area between the radial teeth 3 and the ground is increased, and larger ground grabbing force is obtained.

In one embodiment provided herein, referring to fig. 2, the tire 1 includes an inner ring tire 11 and an outer ring tread body 21, and a plurality of radial teeth 3 are provided on the outer ring tread body 21 in a radial direction of the tire 1. The radial teeth 3 are oriented in the same direction as the radial direction of the tyre 1. By the arrangement mode, when the travelling wheel travels on the ground, the pressure applied to the radial teeth 3 is more balanced, and the radial teeth 3 are not easy to break.

Further, an elastic structure 7 is arranged between the inner ring tire 11 and the outer ring tread body 21, the outer ring tread body 21 is elastically connected with the inner ring tire 11, when part of the tread 2 is contacted with the ground, the elastic structure 7 is compressed, the outer ring tread body 21 deforms, so that the tread 2 with larger area is contacted with the ground, and meanwhile, the number of radial teeth 3 contacted with the ground is also larger. Which not only increases the grip of the travelling wheel further but also reduces the amount of pressure to which the individual radial teeth 3 are subjected.

Referring to fig. 2 and 3, in one embodiment, the elastic structure is a hollow structure between the inner ring tire 11 and the outer ring tread body 21. The hollow structure has a connecting rib 71 along the circumferential direction of the tire 1, a plurality of supporting ribs 72 are arranged on the connecting rib 71 along the radial direction of the tire 1, the supporting ribs 72 respectively connect the inner ring tire 11 with the outer ring tread body 21 at the inner side and the outer side of the connecting rib 71, and hollow holes 73 are arranged between the adjacent connecting ribs 71. When the outer ring tread body 21 receives a large pressure, the outer ring tread body 21 and the supporting ribs 72 deform together, and the hollowed holes 73 are narrowed, so that the contact area between the tread 2 on the outer ring tread body 21 and the ground is increased. The grip of the travelling wheel can be further increased, as well as spreading the pressure over a plurality of radial teeth 3 in contact with the ground.

Further, the running wheel further comprises a wheel cover (not shown in the figure), the outer side surface of the inner ring tyre 11 is provided with a concave mounting cavity 8, and the wheel cover is connected in the mounting cavity 8 in a matching way. Specifically, be equipped with a plurality of buckles position 5 in the installation cavity 8, be equipped with a plurality of buckles on the wheel cap, the buckle can be joined in marriage in buckle position 5, and the wheel cap not only can strengthen the rigidity of tire 1, can also prevent that silt, water stain etc. from getting into in the connection structure 4 on the tire 1.

Referring to fig. 4, an embodiment of the present application further provides an intelligent yard care apparatus, including an apparatus body and the travelling wheel, where the travelling wheel is mounted on the apparatus body. The driving device on the travelling wheel and the intelligent courtyard nursing equipment is connected for driving the intelligent courtyard nursing equipment to travel. When the intelligent yard care equipment travels on the lawn, the radial teeth 3 provided on the travelling wheel can grip more grass, thereby obtaining higher grip. The plurality of radial teeth 3 on the travelling wheel comprises at least two radial teeth 3 of different hardness, the softer radial teeth 3 being able to provide a greater grip on a hard ground when the intelligent yard care appliance travels on the hard ground.

Smart yard care appliances include, but are not limited to: intelligent mower, intelligent scavenging machine, intelligent fertilizer distributor and intelligent sprinkler.

Further, a plurality of radial teeth 3 on the travelling wheel are arranged in a staggered manner, and different radial teeth 3 are arranged at intervals. When the travelling wheel encounters an obstacle with a height difference, the staggered radial teeth still have higher ground grabbing force, and the obstacle crossing capability of the travelling wheel is better. In addition, when the radial teeth 3 are arranged at staggered intervals and run on the ground such as grasslands, mud lands and the like, the capability of preventing mud sticking and grass sticking is better.

In order to facilitate understanding of the technical scheme of the application, a specific application scenario is given below to describe the technical scheme provided by the application in detail.

Application scenario one

The travelling wheel is arranged on an intelligent mower, the intelligent mower can cut and trim lawns of a courtyard, a stone plate road is arranged in the middle of the courtyard, and the lawns of the courtyard are divided into two by the stone plate road. When the intelligent mower travels on the lawn, the radial teeth with harder hardness on the travelling wheel can be inserted into the ground or the root of the dense lawn, and the travelling wheel can obtain higher ground grabbing force when traveling, so that the intelligent mower is not easy to slip. After trimming one lawn, the intelligent mower also needs to trim another lawn. At this moment, the intelligent mower needs to climb over the stone slab road, in the process of climbing over the stone slab road, the travelling wheel is contacted with the ground through radial teeth with softer hardness, the radial teeth can deform, the contact area between the radial teeth and the ground is larger, the obtained ground grabbing force is higher, and the travelling wheel is not easy to slip during travelling on the stone slab road or is clamped between the stone slabs.

Application scene two

The travelling wheel is arranged on intelligent courtyard nursing equipment, and the intelligent courtyard nursing equipment can travel under various road condition environments, such as grasslands, mud lands, stone lands, sand lands, stone lands and the like, when nursing the courtyard. And a plurality of rows of staggered radial teeth are arranged on the travelling wheel, and the radial teeth are arranged at intervals. Not only can improve the grip force of the travelling wheel, but also can improve the mud and water drainage performance. In addition, the plurality of radial teeth includes radial teeth of at least two hardness, and when a stone or the like is accidentally caught between radial teeth of different hardness, the user can easily clean the teeth.

To sum up, in the technical scheme of this application embodiment, the radial teeth of staggered arrangement in row on the tread, and radial teeth include the radial teeth of at least two kinds of hardness, and the great radial teeth of hardness have higher ground force of grabbing on grassland, mud ground, sand ground, and the softer radial teeth of hardness have higher ground force of grabbing on stone road, slabstone road to make the wheel of marcing all have higher ground force of grabbing on the ground of multiple texture, the ability of marcing is better, and the wheel of marcing is difficult to skid. In addition, radial teeth which are staggered in rows on the tread have better mud and water drainage performance.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and are not limiting thereof; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims (15)

1. A travel wheel, comprising:

a tire;

a plurality of radial teeth arranged in rows along a circumferential direction of the tire such that there are a plurality of rows of radial teeth on a tread of the tire;

wherein the radial teeth of different rows are staggered with respect to each other in a direction parallel to the axis of the tire, and the plurality of radial teeth comprises radial teeth of at least two different hardness and structure.

2. The running wheel of claim 1, wherein the tread has at least three rows of radial teeth thereon;

the hardness of the radial teeth of the tread on the outer side is greater than the hardness of the radial teeth of the inner side.

3. The running wheel of claim 2, wherein the tread has three rows of radial teeth thereon, the outer two rows of radial teeth having a hardness greater than the hardness of the middle row of radial teeth;

the hardness of the outer two rows of radial teeth is the same.

4. A travelling wheel according to any one of claims 1 to 3, wherein there is a first gap between two adjacent radial teeth of the same row;

the radial teeth have a dimension in the tire circumferential direction of 0.5 to 3 times the first gap.

5. A travelling wheel according to any one of claims 1 to 3, wherein the radial teeth of the rows of radial teeth are of identical radial tooth structure;

a second gap is arranged between two adjacent rows;

the radial teeth have a dimension in the direction of the tire axis that is 1 to 3 times the second gap.

6. The travelling wheel according to claim 1, wherein the same row of radial teeth has the same structure and the different rows of radial teeth have different structures;

alternatively, the plurality of radial teeth of the same row comprise radial teeth of at least two configurations.

7. The running wheel of claim 6, wherein the configuration of the radial teeth comprises at least two of: prismatic table structure, cone structure.

8. The travel wheel of claim 6, wherein the plurality of rows of radial teeth comprise:

at least one row of multi-structure teeth rows, wherein the multi-structure teeth rows are teeth rows containing at least two structure radial teeth; and/or

At least one row of single-structure teeth, wherein the single-structure teeth are teeth rows containing radial teeth of one structure.

9. The running wheel of claim 8, wherein the tread has three rows of radial teeth thereon;

the two rows at the outer side of the tread are multi-structure tooth rows, and the middle row is a single-structure tooth row.

10. The running wheel of claim 6, wherein the radial teeth of different configurations differ in height and/or hardness.

11. The running wheel of claim 10, wherein the radial tooth height has a value in the range of [3mm to 35mm ].

12. The running wheel of claim 6 wherein the tips of the radial teeth are provided with a pattern configuration, the pattern configuration on the radial teeth being different for different configurations.

13. The running wheel of claim 1, wherein the tire comprises an inner ring tire and an outer ring tread body, the plurality of radial teeth being disposed on the outer ring tread body along a radial direction of the tire;

an elastic structure is arranged between the inner ring tire and the outer ring tread body.

14. The running wheel of claim 13, wherein the elastic structure is a hollowed-out structure between the inner ring tire and the outer ring tread body;

the hollow structure is provided with connecting ribs along the circumferential direction of the tire, a plurality of supporting ribs are arranged on the connecting ribs along the radial direction of the tire, and the supporting ribs respectively connect the inner ring tire with the outer ring tread body at the inner side and the outer side of the connecting ribs;

and hollowed holes are arranged between the adjacent connecting ribs.

15. An intelligent yard care appliance comprising a body and the travelling wheel of any one of claims 1 to 14;

the travelling wheel is mounted on the equipment body.