Hammer housing, hammer assembly and hammer

Abstract

A hammer housing (210) defining an axial cavity (410) extending along a housing axis between a first axial end and a second axial end. The hammer housing comprises a first axial opening at the first axial end of the hammer housing and a second axial opening at the second axial end. The first axial opening receives a housing portion (240) of a hammer tool (145), and the second axial opening receives a piston (205) that provides a reciprocating force relative to the hammer housing to effect reciprocal movement of the tool parallel to the housing axis. A bearing recess arrangement within the axial cavity receives one or more bearing elements to provide one or more bearing surfaces between the hammer housing and the housing portion of the tool. The hammer housing provides an uninterrupted boundary of the axial cavity between the first axial opening and the second axial opening.

Description

[0001] Description

[0002] IMPROVEMENTS IN OR RELATING TO HAMMERS

[0003] Technical Field

[0004] The present disclosure relates generally to a hydraulic hammer of a machine. In particular, the disclosure relates to an interface between a hammer housing and an interchangeable hammer tool within the hammer housing.

[0005] Background

[0006] A hydraulic hammer may be attached to a work machine such as an excavator, a wheel loader, and / or a backhoe, among other examples. The hydraulic hammer may be configured to perform various operations, such as breaking concrete and / or breaking rocks, among other examples. The hydraulic hammer may perform the various operations as a result of a flow of a hydraulic fluid from the work machine.

[0007] Typically, the hydraulic hammer includes a hammer housing that receives a housing portion of the tool and two cylindrical bushings (in the housing) that receive the tool. As the tool is used to perform the various operations discussed above, a movement of the tool and / or a vibration of the tool causes the bushings to experience wear. Typically, the bushings experience uneven wear. For example, small portions of the bushings (e.g., bottom portions) may experience a significant amount of wear while other remaining portions of the bushings may experience insignificant to no amount of wear. In this regard, the bushings may be replaced when the amount of wear, of the small portions, satisfies a wear threshold, despite the other remaining portions of the bushings experiencing insignificant to no amount of wear.

[0008] As an alternative to cylindrical bushings, linear rods may be used. The hammer housing may comprise grooves which retain the linear rods in position and which expose part of each linear rod to the housing portion of the tool to act as a bearing surface with the housing portion of the tool. The housing portion of the tool may comprise channels which correspond to the grooves of the hammer housing such that each rod is partly received in a groove of the hammer housing and partly received in a corresponding channel of the housing portion of the tool. Such an arrangement is disclosed in commonly owned US2024 / 0110362.

[0009] To prevent wear of both the wear bushings and work tool during operation of the hammer, it is conventional to apply lubricant and / or grease to the hammer via a grease supply arrangement and one or more lubricant dispensers so as to lubricate an interface formed between the hammer housing and the moving housing portion of the tool. In some known arrangements, grease / lubricant may be applied via a manual grease dispensingsystem by an operator applying lubricant to the wear bushings using a grease gun via a grease fitting, zerk fitting, etc. of the hammer housing that feeds grease to the wear bushings. In other known arrangements, automated and / or semi-automated grease dispensing systems are present and include grease reservoirs and automated grease application systems that apply grease to the hydraulic hammer assembly at designated intervals of operation.

[0010] Greasing is not merely an occasional maintenance task. Hammer instruction manuals generally advocate greasing a hammer every few hours as a core aspect of hammer operation.

[0011] Furthermore, since it is essential for grease to be appropriately distributed around the entire interface between the housing portion of a hammer tool and the hammer housing into which it is inserted, hammer housings are provided with a grease inlet channel into which grease is dispensed in order to ensure that the grease is appropriately distributed around the interface. The grease inlet channel in the hammer housing is located between a first axial opening at a first axial end of the hammer housing that is configured to receive the housing portion of the hammer tool and the second axial opening at the second axial end of the hammer housing that is configured to receive a piston configured to provide a reciprocating force relative to the hammer housing to effect reciprocal movement of the tool parallel to the housing axis. In this way, the grease is directed via the grease inlet to the annular interface between the exterior of the housing portion of the hammer tool and the interior of the hammer housing.

[0012] It is not possible to achieve the same distribution of grease if the grease is inserted via the first or second axial openings, such as by simply manually placing grease around the exterior surface of the housing portion of the hammer tool when exposed. In any case, even if the exterior surface of the hammer tool is coated with grease, then when the hammer tool is retraced into the hammer housing, much of the grease will fail to enter the small annular gap between the exterior of the housing portion of the hammer tool and the interior of the hammer housing. Thus, instruction manuals instruct users not to insert grease via the first or second axial openings.

[0013] In addition, instruction manuals for hammers generally instruct the operator to add the grease to the grease inlet only when the housing portion of the hammer tool is fully inserted into the hammer housing, in order that the grease can only travel into the annular volume defined between the exterior of the housing portion of the hammer tool and the interior of the hammer housing.

[0014] In short, it has conventionally been considered essential to provide grease to the interface between the hammer housing and the hammer tool, and to provide a dedicated grease inlet for this purpose.Against this background, there is provided a hammer housing defining an axial cavity extending along a housing axis between a first axial end and a second axial end, the hammer housing comprising:

[0015] a first axial opening at the first axial end of the hammer housing, the first axial opening configured to receive a housing portion of a hammer tool;

[0016] a second axial opening at the second axial end of the hammer housing opposite the first axial end of the hammer housing, the second axial opening configured to receive a piston configured to provide a reciprocating force relative to the hammer housing to effect reciprocal movement of the tool parallel to the housing axis; and

[0017] a bearing recess arrangement within the axial cavity configured to receive one or more bearing elements to provide one or more bearing surfaces between the hammer housing and the housing portion of the tool;

[0018] wherein the hammer housing provides an uninterrupted boundary between the first axial opening at the first axial end of the hammer housing and the second axial opening at the second axial end of the hammer housing.

[0019] Brief Description of the Drawings

[0020] FIG. 1 is a schematic diagram of an example machine described herein; FIG. 2 is a schematic diagram of a perspective view (with interior components visible) of an example of a hydraulic hammer comprising a hammer housing in accordance with the prior art and an interchangeable hammer tool wherein the hammer housing is of the kind configured to receive cylindrical bushings and comprises a grease supply channel arrangement;

[0021] FIG. 3 is a schematic diagram of a cross-sectional view of the hammer housing shown in FIG. 2, the hammer housing comprising a bearing recess arrangement within the axial cavity in which are received annular bearing elements to provide one or more bearing surfaces between the hammer housing and the housing portion of the tool and including a grease supply channel arrangement extending radially between the axial cavity and an exterior of the hammer housing;

[0022] FIG. 4 is a schematic diagram of a cross-sectional view of a hammer housing with a bearing recess arrangement within the axial cavity in which are received annular bearing elements to provide one or more bearing surfaces between the hammer housing and the housing portion of the tool and including a grease supply channel arrangement extending radially between the axial cavity and an exterior of the hammer housing;FIG. 5 is a schematic diagram of a perspective view of a hammer housing in accordance with the disclosure with interior components visible, wherein the hammer housing is of the kind configured to receive rods in place cylindrical bushings and wherein the hammer housing comprises no grease supply channel such that the hammer housing provides an uninterrupted boundary between the first axial opening at the first axial end of the hammer housing and the second axial opening at the second axial end of the hammer housing;

[0023] FIG. 6 is a schematic diagram of a perspective view of the hammer housing of FIG 5. without the rods and without the hammer tool;

[0024] FIG. 7 is a schematic cross sectional view of the hammer housing of FIGS.

[0025] 5 and 6 with grooves occupied by rods and without the hammer tool;

[0026] FIG. 8 is a schematic partial cross sectional view of the hammer housing of FIGS. 5 to 7 with grooves occupied by rods and the hammer tool in situ;

[0027] FIG. 9 is a schematic diagram of a cross sectional shape of one of the first plurality of grooves and one of the second plurality of grooves in accordance with the example hammer housing of FIGS. 5 to 8; and

[0028] FIG. 10 is a schematic diagram of a perspective view of an example of a hydraulic hammer comprising a hammer housing in accordance with the disclosure wherein the hammer housing is of the kind configured to receive cylindrical bushings and comprises no grease supply channel such that the hammer housing provides an uninterrupted boundary between the first axial opening at the first axial end of the hammer housing and the second axial opening at the second axial end of the hammer housing.

[0029] Detailed Description

[0030] FIG. 1 is a diagram of an example machine 100 described herein. As shown in FIG. 1, machine 100 is embodied as an earth moving machine, such as an excavator. Alternatively, the machine 100 may be another type of machine, such as a backhoe loader or a dozer.

[0031] The term “machine” may refer to a device that performs an operation associated with an industry such as, for example, mining, construction, farming, transportation, or another industry. Moreover, one or more implements may be connected to the machine. As an example, a machine may include a construction vehicle, a work vehicle, or a similar vehicle associated with the industries described above.

[0032] As shown in FIG. 1, the machine 100 includes ground engaging members 110, a machine body 115, and an operator cabin 120. Ground engaging members 110 may include tracks (as shown in FIG. 1), wheels, rollers, and / or the like, for propelling machine 100. Ground engaging members 110 are mounted to a rotating frame (not shown) and are driven by one or more engines and drive trains (not shown). Machinebody 115 is mounted on the rotating frame (not shown). Operator cabin 120 is supported by machine body 115 mounted on the rotating frame. Operator cabin 120 includes an integrated display (not shown) and operator controls 125, such as, for example, an integrated joystick. Operator controls 125 may include one or more input components. In some examples, the controller may provide a notification indicating that the machine has transitioned from operating in the first lifting mode to operating in the second lifting mode.

[0033] For an autonomous machine, operator controls 125 may not be designed for use by an operator and, rather, may be designed to operate independently from an operator. In this case, for example, operator controls 125 may include one or more input components that provide an input signal for use by another component without any operator input. Machine 100 may include a swivel member (not shown) that enable the rotating frame (and machine body 115) to rotate (or swivel). For example, the swivel element may enable the rotating frame (and machine body 115) to rotate (or swivel) with respect to ground engaging members 110.

[0034] As shown in FIG. 1, machine 100 includes a boom 130, a stick 135, and a hammer 140 comprising a hammer housing 210 and a hammer tool 145. Boom 130 is pivotally mounted at its proximal end to machine body 115 and is articulated relative to machine body 115 by one or more fluid actuation cylinders (e.g., hydraulic or pneumatic cylinders), electric motors, and / or other electro-mechanical components. Stick 135 is pivotally mounted at a distal end of boom 130 and is articulated relative to boom 130 by one or more fluid actuation cylinders, electric motors, and / or other electro-mechanical components. Boom 130 and / or stick 135 may be referred to as a linkage. Hammer 140 is mounted at a distal end of stick 135 and may be articulated relative to stick 135 by one or more fluid actuation cylinders, electric motors, and / or other electro-mechanical components.

[0035] As an example, a hydraulic pump (not shown) may be configured to provide hydraulic fluid (e.g., pressurized hydraulic fluid) to cause one or more one or more hydraulic cylinders 150 to articulate boom 130, stick 135, and / or hammer 140, as described above. In this regard, hammer 140 may be referred to as a hydraulic hammer. A hydraulic supply system (associated with the hydraulic pump) may drive hammer 140 to provide a reciprocating impact motion to tool 145. The hydraulic system may drive the tool 145.

[0036] Based on the reciprocating impact motion, tool 145 may perform various operations, such as breaking concrete, breaking rocks, and / or chipping metal slag from pots in a foundry, among other examples. For example, tool 145 may be actuated to produce cyclic vibrational movement at an intensity sufficient to perform the various operations discussed above. As shown in FIG. 1, as an example, tool 145 may include a bit. Alternatively, tool 145 may include other components that are configured to be receivedwithin the hammer housing 210 such that when actuated they perform one or more of the various actions discussed above.

[0037] As shown in FIG. 1, machine 100 includes a controller 155 (e.g., an electronic control module (ECM), a computer vision controller, an autonomy controller, among other examples) and one or more inertial measurement units (IMlls) 160 (referred to herein individually as “IMU 150,” and collectively referred to as “IMlls 160 ”).

[0038] Controller 155 may control and / or monitor operations of machine 100.

[0039] As shown in FIG. 1, IMlls 160 are installed at different positions on components or portions of machine 100, such as, for example, on machine body 115, boom 130, stick 135, and hammer 140. An IMU 160 includes one or more devices that are capable of receiving, generating, storing, processing, and / or providing signals indicating a position and orientation of a component, of machine 100, on which the IMU 160 is installed. While the example discussed herein refers to IM Us 160, the present disclosure is applicable to using one or more other types of sensor devices that may be used to determine a position and orientation of a component of machine 100.

[0040] As indicated above, FIG. 1 is provided as an example. Other examples may differ from what was described in connection with FIG. 1.

[0041] FIG. 2 is a schematic diagram of a perspective view (with interior components visible) of an example of a hydraulic hammer comprising a hammer housing 210 in accordance with the prior art and an interchangeable hammer tool 145. The hammer housing 210 is of the kind configured to receive cylindrical bushings 296, 298 and comprises a grease supply channel 450.

[0042] Hammer housing 210 may comprise a metal, a polymer, and / or a plastic material, among other examples. Hammer housing 210 may be configured to receive a portion of tool 145 into an axial cavity 410 of the hammer housing (shown in FIG 3). For example, hammer housing 210 may be configured to receive a housing portion 240 of tool 145. An exposed portion 250 of tool 145 may be external with respect to hammer housing 210.

[0043] The hammer housing 210 may further comprise a tool retainer 260, and a tool stop member 270. The stop member 270 may comprise a metal, a polymer, and / or a plastic material, among other examples. In some instances, tool stop member 270 may be configured to limit a movement of tool 145 that may cause tool 145 to be removed from housing 210 (e.g., limit a movement of tool 145 that may cause tool 145 to drop / fall out of housing 210). By preventing the movement of tool 145 in this manner, tool stop member 270 may prevent damage to components of machine 100.

[0044] A distance between housing portion 240 and a work end 290 of tool 145 may exceed a distance between exposed portion 250 and work end 290. In somesituations, depending on an orientation of hammer 140, housing portion 240 may be a top portion of tool 145 and exposed portion 250 may be a bottom portion of tool 145. For example, when hammer 140 is provided in a vertical position as shown in FIG. 2, housing portion 240 may be the top portion that is provided above the bottom portion of

[0045] tool 145 (e.g., provided above exposed portion 250).

[0046] Hammer housing 210 may include a power cell (not shown) and a piston 205. The power cell may utilize a fluid (e.g., a hydraulic and / or a pneumatic fluid), to reciprocally impact the piston 205 against an upper end of housing portion 240 to drive tool 145 to perform the various operations discussed herein.

[0047] FIG. 3 is a schematic diagram of a cross-sectional view of the hammer housing 210 shown in FIG. 2 and without the hammer tool 145. In use, the housing portion 240 of the hammer tool 145 is inserted into the axial cavity 410 of the hammer housing 410. The hammer housing 210 comprises a bearing recess arrangement within the axial cavity in which are received annular bearing elements in the form of cylindrical bushings 296, 298. The cylindrical bushings 296, 298 provide bearing surfaces between the hammer housing 210 and the housing portion 240 of the tool 145. The hammer housing 210 includes a grease supply channel arrangement 450 extending radially between the axial cavity 410 and an exterior of the hammer housing 210. The grease supply channel arrangement 450 has a plurality of grease supply inlets into the axial cavity, each adjacent one of the annular bushings. The grease supply arrangement 450 is configured to facilitate the supply of grease into the bearing recess arrangement. Each cylindrical bushing 296, 298 may comprise an access port 297, 299 configured to convey grease from the bearing recess arrangement into the axial cavity 410 that is configured to receive the housing portion 240 of the hammer tool 145. In this way, when the piston 205 reciprocates so as to cause reciprocation of the hammer tool 145 relative to the cylindrical bushings 296, 298 grease is supplied to lubricate the surfaces that rub against one another, namely a radially outer surface of the housing portion 240 of the hammer tool 145 and a radially inner surface of the cylindrical bushings 296, 298.

[0048] In a more recent development, the cylindrical bushings 296, 298 of FIGS. 2 and 3 have been substituted by an arrangement of linear rods. FIG. 4 shows an arrangement that corresponds to FIG. 3 wherein the cylindrical bushings 296, 298 are substituted with linear rods 220.

[0049] In particular, the hammer 140 of FIG. 4 includes a plurality of rods 220, 230 within the hammer housing 210 configured to guide the housing portion 240 of the tool 145 when the tool 145 is being received by the housing 210 and to engage the housing portion 240 of the tool 145 in the housing 210 after the tool 145 has been received.In implementations that deploy a plurality of rods, the rods are configured to engage a tool received by the hammer housing. The plurality of rods may be provided circumferentially around the tool in the housing. The plurality of rods may provide a guiding surface for guiding the tool as the tool is being received by the housing.

[0050] The plurality of rods may be configured to distribute wear, caused by a movement of the tool, to multiples rods. Each rod of the plurality of rods may be replaced individually as an amount of wear of the rod satisfies a wear threshold (e.g., as the amount of wear reaches a wear limit). In some examples, the plurality of rods may be inserted into the housing via an opening in a portion of the housing (e.g., via an opening in a front head of the housing).

[0051] The housing portion of the tool may include a plurality of channels corresponding to the number of grooves in the housing. The channels may be configured such that each rod is accommodated in part by its groove in the housing and in part by its channel in the housing portion of the tool.

[0052] The hammer housing may comprise a first plurality of rods 220, a second plurality of rods 230, a tool retainer 260, and a tool stop member 270. Hammer housing 210 may comprise a metal, a polymer, and / or a plastic material, among other examples. Hammer housing 210 may be configured to receive a portion of tool 145. For example, hammer housing 210 may be configured to receive a housing portion 240 of tool 145. An exposed portion 250 of tool 145 may be external with respect to hammer housing 210.

[0053] A distance between housing portion 240 and a work end 290 of tool 145 may exceed a distance between exposed portion 250 and work end 290. In some situations, depending on an orientation of hammer 140, housing portion 240 may be a top portion of tool 145 and exposed portion 250 may be a bottom portion of tool 145. For example, when hammer 140 is provided in a vertical position as shown in FIG. 1, housing portion 240 may be the top portion that is provided above the bottom portion of

[0054] tool 145 (e.g., provided above exposed portion 250).

[0055] In some examples, a size, a shape, and / or a weight of two or more rods, of the first plurality of rods, may be same. Accordingly, the two or more rods may be configured to replace each other. Similarly, a size, a shape, and / or a weight of two or more rods, of the second plurality of rods, may be same. Accordingly, the two or more rods (of the second plurality of rods) may be configured to replace each other. Furthermore, at least one rod (of the first plurality of rods) and at least one rod (of the second plurality of rods) may be configured to replace each other.

[0056] One or more rods, of the first plurality of rods, may be rotatably provided in the housing such that the one or more rods are configured to rotate as a result of a movement of the tool. Based on the one or more rods rotating during the movement of thetool, an amount of wear experienced by a rod may be distributed to multiple portions of the rod (as opposed to a small single bottom portion of the rod).

[0057] The tool retainer 260 may retain the tool in position in the hammer housing 210. The tool stop member 270 may prevent the tool from moving further into the housing than intended. Between the hammer housing 210 and the tool 145 there may be provided a first plurality of rods 220 and second plurality of rods 230. First plurality of rods 220 may be configured to engage a first portion of housing portion 240 of tool 145. First plurality of rods 220 may be parallel to a longitudinal axis 280 of tool 145. First plurality of

[0058] rods 220 may be circumferentially provided around tool 145 when tool 145 is received by housing 210.

[0059] In the example of FIG. 4, the hammer housing 210 comprises a grease supply arrangement 450 which enables supply of grease into the annular cavity 410 adjacent the plurality of rods 230.

[0060] With the introduction of a solution that includes a plurality of rods 220, 230 in place of cylindrical bushings 296298, the Applicant has surprisingly identified that the degree of wear between the rods and the housing portion 240 of the tool 145 may be reduced to the extent that grease is not required. Accordingly, it is possible to eliminate the need for a grease supply arrangement 450. In this way, it is possible to eliminate the distribution of grease into a work site in which the hammer is in use. This may be particularly advantageous when it is desirable to avoid grease from making its way into the material being manipulated by the hammer 140. Furthermore, without a grease supply arrangement, it is possible to avoid a situation where contaminants enter the hammer via a grease supply arrangement. In addition, the absence of a grease supply arrangement means that there are fewer parts requiring servicing and cleaning, and fewer parts that may be vulnerable to damage, such as pipework.

[0061] FIG. 5 is a schematic diagram of a perspective view of a hammer in accordance with the disclosure with interior components visible, wherein the hammer housing comprises no grease supply channel. In this way, the hammer housing provides an uninterrupted boundary between the first axial opening at the first axial end of the hammer housing and the second axial opening at the second axial end of the hammer housing.

[0062] FIG. 6 is a schematic diagram of a perspective view of the hammer housing of FIG 5. without the rods and without the hammer tool.

[0063] In some examples, a size, a weight and / or a shape of two or more rods, of first plurality of rods 220, may be same. For example, a length of a first rod (of first plurality of rods 220) may be same as a length of a second rod (of first plurality of rods 220), a width of the first rod may be same as a width of the second rod, a diameter of the first rod may be same as a diameter of the second rod, a weight of the first rod may be same as a weight ofthe second rod, and / or a shape of the first rod may be same as a shape of the second rod. Accordingly, the first rod and the second rod may be configured to replace each other.

[0064] A rod, of first plurality of rods 220, may comprise steel. Additionally, or alternatively, the rod may comprise brass, carbide, and / or a non-metallic material. In some implementations, the rod may have a diameter of approximately 53 mm, a length of approximately 300 mm, and a weight of approximately 5 kg.

[0065] In some examples, first plurality of rods 220 may be rotatably provided in hammer housing 210. For example, one or more rods, of first plurality of rods 220, may be configured to rotate during a movement of tool 145 (e.g., during an operation of tool 145). By rotating in this manner, an amount of wear of a rod may be distributed to multiple portions of the rod, as opposed to a single portion of the rod experiencing wear. By distributing the amount of wear to multiple portions, a life of the rod may be extended.

[0066] Accordingly, the rod may not be replaced prematurely.

[0067] As shown in FIG. 7, second plurality of rods 230 may be configured to engage a second portion of housing portion 240 of tool 145. The second portion of housing portion 240 may be opposite with respect to the first portion of housing portion 240. The second plurality of rods 230 may be parallel to longitudinal axis 280 of tool 145. Second plurality of rods 230 may be circumferentially provided around tool 145 when tool 145 is received by housing 210.

[0068] In some examples, a size, a weight, and / or a shape of two or more rods, of second plurality of rods 230, may be same. For example, a length of a third rod (of second plurality of rods 230) may be same as a length of a fourth rod (of second plurality of rods 230), a width of the third rod may be same as a width of the fourth rod, a diameter of the third rod may be same as a diameter of the fourth rod, a weight of the third rod may be same as a weight of the fourth rod, and / or a shape of the third rod may be same as a shape of the fourth rod. Accordingly, the third rod and the fourth rod may be configured to replace each other.

[0069] Similarly, a size, a weight, and / or a shape of one or more first rods, of first plurality of rods 220, may be same as a size, a weight, and / or a shape of one or more second rods of second plurality of rods 230. Accordingly, the one or more first rods and the one or more second rods may be configured to replace each other. For example, the first rod and the third rod may be configured to replace each other.

[0070] In some examples, second plurality of rods 230 may be rotatably provided in hammer housing 210. For example, one or more rods, of second plurality of rods 230, may be configured to rotate during a movement of tool 145 (e.g., during an operation of tool 145). By rotating in this manner, an amount of wear of a rod may be distributed to multiple portions of the rod, as explained above in connection with first plurality of rods 220.In some implementations, a quantity of second plurality of rods 230 is equal to a quantity of first plurality of rods 220. In some implementations, housing 210 may include a single plurality of rods. For example, hammer housing 210 may include second plurality of rods 230 without including first plurality of rods 220. Alternatively,

[0071] housing 210 may include first plurality of rods 220 without including second plurality of rods 230.

[0072] As shown in FIG. 7, tool retainer 260 may be provided between first plurality of rods 220 and second plurality of rods 230. The tool retainer 260 may retain the first plurality of rods 220 and second plurality of rods 230 in their respective grooves. Tool retainer 260 may comprise a metal, a polymer, and / or a plastic material, among other examples. In some instances, tool retainer 260 may be configured to limit a movement of tool 145, along longitudinal axis 280, in a direction toward first plurality of rods 220. For example, when hammer 140 is provided in a vertical position as shown in FIG. 1, the movement may be an upward movement and the direction may be an upward direction. By prevent the movement of tool 145 in this manner, tool retainer 260 may prevent damage to hammer 140 and / or to components of machine 100, such as boom 130 and / or stick 135, among other examples.

[0073] With reference to FIG. 6, the hammer housing 210 comprises an axial cavity 410. The hammer housing 210 further comprises a first plurality of grooves 420 (numbered individually as 421, 422, 423, 424, 425, 426, 427, 428, 429, 430, 431, 432). Each groove of the first plurality of grooves 420 is linear and coaxial with and connected to the axial cavity 410. The hammer housing 210 further comprises a second plurality of grooves 440 (not numbered individually) each coaxial with and connected to the axial cavity 410. Each groove of the second plurality of grooves 420 is linear and coaxial with and connected to the axial cavity 410.

[0074] Each of the first plurality of grooves 420 may correspond with one of the second plurality of grooves 440. Each corresponding pair of grooves from the first plurality of grooves 420 and the second plurality of grooves 440 may be on a single groove pair axis 510 (shown in FIG. 9) either side of the tool retainer 260.

[0075] Each groove of the first plurality of grooves 420 and the second plurality of grooves 440 may be configured to surround more than 180° but less than 360° of a corresponding rod when inserted into said groove. In this way, although the groove is connected to the axial cavity 410, once a rod is inserted into said groove it is retained within said groove and cannot move into the axial cavity 410. This is because the opening between the groove and the axial cavity 410 has a smaller dimension than the diameter of a rod which fills the groove.On insertion of a rod into one of the grooves, more than half of the exterior wall of the rod is surrounded by the groove. A portion of the exterior wall of the rod that is not surrounded by the groove is exposed to an interior volume of the axial cavity 410.

[0076] In this way, when each of the grooves is occupied by a rod and the housing portion 240 of a tool is inserted into the axial cavity 410, the housing portion 240 of the tool makes contact with the radially outermost part of each of the rods.

[0077] FIG. 8 is a diagram 300 of a cross-sectional view of a portion of the hammer housing 210, rods 220, 230, 220-1, 220-2 and housing portion of the tool 145. With reference to FIG. 8, the housing portion 240 of the tool may comprise a plurality of channels 310, 320. Each rod 220, 230, 220-1, 220-2 may thus be partly accommodated by its groove in the hammer housing and partly accommodated by its channel in the housing portion 240 of the tool. The number of channels may be equal to the number of grooves.

[0078] FIG. 9, shows a schematic view of a cross section through a groove pair axis 510 of one of the first plurality of grooves 421 and a corresponding one of the second plurality of grooves 441. All groove pairs may have the same dimensions and shapes as all other groove pairs. The relative dimensions and shapes are shown in exaggerated form for the purposes of illustration.

[0079] Each groove of the first plurality of grooves and each groove of the second plurality of grooves comprises a first axial end 502 proximate the tool retainer 260 and a second axial end 504 opposite the first axial end 502.

[0080] The first axial end 502 of each groove has a consistent cross sectional shape and dimensions in each cross section orthogonal to the housing axis.

[0081] The second axial end 504 of each groove comprises a flared region that flares outwardly with distance from the tool retainer 260.

[0082] The flared region may comprise up to 40% of a length of the groove (such that at least 60% of the groove is unflared). The flared region may comprise up to 25% of the length of the groove (such that at least 75% of the groove is unflared). The flared region may comprise up to 15% of the length of the groove (such that at least 85% of the groove is unflared).

[0083] Since the rods are not flared, and have a constant cross section, the rod does not make contact with the groove in the flared regions.

[0084] Contact pressure is likely to be highest furthest from the tool retainer 260. Thus, by flaring the ends of the grooves furthest from the tool retainer 260, the rods do not make contact with the grooves in this region, which reduces the maximum contact pressure between the rod and the groove considerably. Reductions in contact pressure give rise to the possibility of operation without grease which gives rise to the provision of an uninterrupted boundary between the first axial opening at the first axial end of the hammerhousing and the second axial opening at the second axial end of the hammer housing, since no grease supply channels are provided.

[0085] In the illustrated embodiments that comprise rods, each rod is a cylinder and therefore each groove has a cross sectional shape that is part circular. Other shapes of groove and rod would be possible and fall within the scope of the disclosure.

[0086] In some arrangements, a largest diameter of the second axial end 504 of each groove may have a diameter that is less than 10% greater than the diameter of the first axial end 502 of each groove. In other arrangements, the largest diameter of the second axial end 504 of each groove may have a diameter that is less than 8% greater than the diameter of the first axial end 502 of each groove. In other arrangements, the largest diameter of the second axial end 504 of each groove may have a diameter that is between 6% and 7% greater than the diameter of the first axial end 502 of each groove.

[0087] In one specific arrangement, the first axial end 502 of each groove may have a diameter of 30 mm and a largest diameter of the second axial end 504 of each groove may have a diameter of 32 mm.

[0088] The Applicant has further determined that a grease supply channel 450 may not only be eliminated in implementations comprising rods but also in implementations comprising cylindrical bushings in place of rods.

[0089] Industrial Applicability

[0090] Implementations described herein are directed to deploying hammer housings with an uninterrupted boundary between the first axial opening at the first axial end of the hammer housing and the second axial opening at the second axial end of the hammer housing. The uninterrupted boundary is made possible by the fact that there is no grease distribution channel arrangement.

[0091] Thus, implementations described herein may lower overall operating costs associated with the hammer and eliminate the introduction of hammer related grease into the work site where the hammer is in use.

[0092] The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementations to the precise forms disclosed. Modifications and variations may be made in light of the above disclosure or may be acquired from practice of the implementations. Furthermore, any of the implementations described herein may be combined unless the foregoing disclosure expressly provides a reason that one or more implementations cannot be combined.

[0093] As used herein, “a,” “an,” and a “set” are intended to include one or more items, and may be used interchangeably with “one or more.” Further, as used herein, the article “the” is intended to include one or more items referenced in connection with the article “the” and may be used interchangeably with “the one or more.” Further, the phrase“based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and / or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of”). Further, spatially relative terms, such as “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. The spatially relative terms are intended to encompass different orientations of the apparatus, device, and / or element in use or operation in addition to the orientation depicted in the figures. The apparatus may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may likewise be interpreted accordingly.

[0094] It is to be understood that at least some of the figures and descriptions of the disclosure have been simplified to focus on elements that are relevant for a clear understanding of the disclosure, while eliminating, for purposes of clarity, other elements that the reader skilled in the art will appreciate may also be required. Because such elements are well known to the reader skilled in the art, and because they do not necessarily facilitate a better understanding of the disclosure, a description of such elements is not provided herein.

Claims

Claims1. A hammer housing defining an axial cavity extending along a housing axis between a first axial end and a second axial end, the hammer housing comprising:a first axial opening at the first axial end of the hammer housing, the first axial opening configured to receive a housing portion of a hammer tool;a second axial opening at the second axial end of the hammer housing opposite the first axial end of the hammer housing, the second axial opening configured to receive a piston configured to provide a reciprocating force relative to the hammer housing to effect reciprocal movement of the tool parallel to the housing axis; anda bearing recess arrangement within the axial cavity configured to receive one or more bearing elements to provide one or more bearing surfaces between the hammer housing and the housing portion of the tool;wherein the hammer housing provides an uninterrupted boundary of the axial cavity between the first axial opening at the first axial end of the hammer housing and the second axial opening at the second axial end of the hammer housing.

2. The hammer housing of claim 1 wherein the first axial end of the hammer housing comprises a first end surface that is orthogonal to the housing axis and wherein the first axial opening is surrounded by the first end surface.

3. The hammer housing of claim 1 or claim 2 wherein the second axial end of the hammer housing comprises a second end surface that is orthogonal to the housing axis and wherein the second axial opening is surrounded by the second end surface.

4. The hammer housing of any preceding claim wherein the bearing recess comprises:a first plurality of grooves each coaxial with and connected to the axial cavity, wherein the first plurality of grooves is configured to receive a first plurality of rods provided in the hammer housing and configured to engage a first portion of the housing portion of the tool; anda second plurality of grooves each coaxial with and connected to the axial cavity and axially offset from the first plurality of grooves, wherein the second plurality of grooves is configured to receive a second plurality of rods provided in the hammer housing and configured to engage a second portion of the housing portion of the tool.

5. The hammer housing of claim 4 further comprising:a tool retainer between the first plurality of grooves and the second plurality of grooves;wherein each groove of the first plurality of grooves and each groove of the second plurality of grooves comprises a first axial end proximate the tool retainer and a second axial end opposite the first axial end;wherein the first axial end of each groove has a consistent cross sectional shape and dimensions in each cross section orthogonal to the housing axis; and wherein the second axial end of each groove comprises a flared region that flares outwardly with distance from the tool retainer.

6. The hammer housing of claim 4 or claim 5 when dependent upon claim 4 wherein each of the first plurality of grooves has a circular cross section and each of the second plurality of grooves has a circular cross section.

7. The hammer housing of any preceding claim wherein each flared region is frustoconical.

8. The hammer housing of any preceding claim wherein a largest diameter of the second axial end of each groove has a diameter that is at least 1% greater than the diameter of the first axial end of each groove.

9. The hammer housing of any preceding claim wherein a largest diameter of the second axial end of each groove has a diameter that is less than 10% greater than the diameter of the first axial end of each groove.

10. The hammer housing of claim 9 wherein a largest diameter of the second axial end of each groove has a diameter that is between 6% and 7% greater than the diameter of the first axial end of each groove.

11. The hammer housing of any preceding claim wherein a length of the first axial end of each groove is at least 60% of a total length of said groove, preferably at least 75% of the total length of said groove, more preferably at least 85% of the total length of said groove.

12. The hammer housing of any preceding claim wherein the tool retainer is configured to retain the plurality of rods in place.

13. The hammer housing of any of claims 1 to 3 wherein the bearing recess arrangement comprises an annular groove within the axial cavity configured to receive a cylindrical bearing.

14. The hammer housing of claim 13 wherein the annular groove is one of a plurality of annular grooves and the bearing recess arrangement comprises the plurality of annular grooves.

15. A hammer assembly comprising the hammer housing of any preceding claim and a plurality of rods configured to be received into the grooves of the hammer housing.

16. The hammer assembly of claim 15 wherein the tool retainer is configured to retain the plurality of rods in place within the housing.

17. A hammer comprising the hammer assembly of claim 15 and a tool comprising a housing portion having a plurality of channels, wherein each channel of the plurality of channels corresponds with a groove of the plurality of grooves.

18. The hammer of claim 17 wherein the tool retainer is configured to retain the housing portion of the tool in place within the housing.

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