GB2579822A

GB2579822A - A pump for an internal combustion engine

Info

Publication number: GB2579822A
Application number: GB1820437.0A
Authority: GB
Inventors: J Laity Kevin; Kahraman Erol
Original assignee: Delphi Technologies IP Ltd
Current assignee: Delphi Technologies IP Ltd
Priority date: 2018-12-14
Filing date: 2018-12-14
Publication date: 2020-07-08
Also published as: GB201820437D0

Abstract

A pump 200 has a tubular pressure pulse damping member 300 which has an at least partial toroidal form, where there is a elongate component 235 of the pump which extends past or through the at least part toroidal damper, the damper having inner and outer walls which are at least part annular, the damper having a cavity which is filled with damping fluid. The damper may deform radially relative to the elongate member. The cavity may be annular and fully surround the elongate component. The damper may be formed of at least two parts which are fixed together. The damping fluid may be an inert gas. The pump may be used in conjunction with an internal combustion engine, which may be used in conjunction with a vehicle. Also claimed is a method of manufacture of the pump including the at least part toroidal pressure pulse damping member.

Description

A PUMP FOR AN INTERNAL COMBUSTION ENGINE

FIELD OF THE INVENTION

The present disclosure relates to a pump for an internal combustion engine and a method of making a pump. Aspects of the invention relate to a pump, an internal combustion engine, a vehicle and a method.

BACKGROUND ART

Pressure pulsations may be generated in a low pressure circuit of a pump of an internal combustion engine due to changes in cambox volume in the pump (as the pump's plunger is driven) and due to closures of the pump valves, such as the inlet 15 valve.

These pressure pulsations can sometimes be very severe and can cause damage to the components of the internal combustion engine such as, for example, a fuel filter of the engine's fuel injection system.

The pulsations can even affect the pump's functionality. Pulsations in the low pressure circuit will provide inconsistent filling pressure to the inlet valve. Unpredictable inlet valve operation will lead to poor pump volumetric efficiency (VE) and rail pressure control (RPC). Poor VE is associated with poor engine performance and a need to increase the size of the pump, which is undesirable.

Poor RPC often leads to pressure variations at the injector, and therefore results in poor emissions control. Low pressure pulsations may also lead to drive train durability issues.

Until now, it has been common practice to use disc-shaped damper capsules 10, as shown in Figure 1, to minimize pressure pulsations in pumps 20 of internal combustion engines. Such damper capsules 10 are typically arranged to extend across circular openings 30 in pumps 20, as shown in Figure 2, to provide damping of pulsations generally in a direction perpendicular to the plane of the disc.

Such disc-shaped dampers 10 are typically difficult to install in a pump 20 due to their size and shape. Moreover, due to their arrangement across circular openings 30, these disc-shaped dampers 10 can act as a 'drum' and generate high levels of unwanted noise.

It is against this background that the invention has been devised.

SUMMARY OF THE INVENTION

According to an aspect of the invention, there is provided a pump for an internal combustion engine, the pump comprising: an elongate component extending longitudinally along a longitudinal axis and radially away from the longitudinal axis along a radial axis; a pump body at least partially surrounding the elongate component, the pump body comprising an annular or part-annular cavity at least partially surrounding the elongate component; and a toroidal or part-toroidal damper for absorbing pressure pulsations in the pump, the damper being arranged in the cavity to at least partially surround the elongate component, and comprising inner and outer annular or part-annular walls and a chamber between the inner and outer walls, the chamber containing a damping fluid, wherein the inner wall surrounds at least a part of the elongate component.

The damper may be configurable to deform radially along the radial axis.

The cavity may be annular and entirely surround the elongate component. When the cavity is annular and entirely surrounds the elongate component, the damper may be toroidal and comprise inner and outer annular walls and the inner wall may entirely surround the elongate component.

The inner and outer walls may be elongate along the longitudinal axis. The chamber may have a substantially elliptical or rectangular cross-section in a plane containing the longitudinal axis and the radial axis.

The damper may comprise inner and outer parts, the inner part comprising the inner wall and the outer part comprising the outer wall, and the inner and outer parts being fixedly attached. The inner and outer parts may comprise a flange at each end of the inner and outer parts. When the inner and outer parts comprise a flange at each end of the inner and outer parts, the inner and outer parts may be fixedly attached at the flange. Each flange may be located inside the chamber or outside the chamber. In one preferred embodiment, the inner and outer parts are substantially made of stainless steel.

The damper may be made up of at least two part-annular damper segments.

When the damper is made up of at least two part-annular damper segments, the damper may comprise at least one curved biasing means configured to wrap around an outer segment wall of each damper segment such that each damper segment is fixed in place.

The damping fluid may be a gas, and the gas is preferably an inert gas. In one preferred embodiment, the inert gas is argon. The gas may have a pressure between approximately 1 bar and 5 bar, and preferably has a pressure of approximately 3 bar.

The invention extends to an internal combustion engine comprising the pump described above. The invention further extends to a vehicle comprising the internal combustion engine described above.

According to a further aspect of the invention, there is provided a method of making a pump for an internal combustion engine, the method comprising: providing a pump comprising an elongate component and a pump body surrounding the elongate component; providing a toroidal or part-toroidal damper for absorbing pressure pulsations in the pump, wherein the damper comprises inner and outer annular or part-annular walls and a chamber between the inner and outer walls, and the chamber contains a damping fluid; and arranging the damper in an annular or part-annular cavity of the pump body, the cavity at least partially surrounding the elongate component, such that the inner wall of the damper surrounds at least a part of the elongate component.

The cavity may be open at a face of the pump body. The pump may comprise a further body, the further body supporting the elongate component. When the cavity is open at a face of the pump body and the pump comprises a further body, the further body supporting the elongate component; the step of arranging the damper in the cavity may comprise arranging the damper around the elongate component of the further body and passing the elongate component through the cavity until the damper surrounding the elongate component is located in the cavity and the further body closes the cavity.

The damper may include at least two damper segments. When the damper includes at least two damper segments, the step of arranging the damper in the cavity comprises arranging each segment of the damper in the cavity, providing a curved biasing means, and wrapping the curved biasing means around an outer segment wall of each damper segment such that the damper is fixed in place.

Features of any one aspect or embodiment of the invention may be used, alone or in appropriate combination, with other aspects and embodiments as appropriate.

BRIEF DESCRIPTION OF DRAWINGS

Figures 1 and 2, which are respectively a perspective view of a disc-shaped damper capsule of the prior art and a perspective view of a pump comprising the damper of Figure 1, have already been described above by way of background to the invention. The above and other aspects of the invention will now be described, by way of example only, with reference to the remainder of the accompanying drawings, in which: Figure 3 is a schematic view of a vehicle comprising an internal combustion engine; Figure 4 is a cross-section of a pump for the internal combustion engine of Figure 3, the pump having a toroidal damper; Figure 5 is a perspective view of the damper of Figure 4 in accordance with one embodiment of the invention; Figure 6 is a side view of the damper of Figure 5; Figure 7 is a top-down view of the damper of Figure 5; Figure 8 is a cross-section of the damper of Figure 5; Figure 9 is another cross-section of the damper of Figure 5; Figure 10 is a cross-section of an inner part of the damper of Figure 5; Figure 11 is a cross-section of an outer part of the damper of Figure 5; Figure 12 is a perspective view of the damper of Figure 4 in accordance with another embodiment of the invention; Figure 13 is a side view of the damper of Figurel2; Figure 14 is a top-down view of the damper of Figure 12; Figure 15 is a cross-section of the damper of Figure 12; Figure 16 is another cross-section of the damper of Figure 12; Figure 17 is a perspective view of the damper of Figure 4 in accordance with another embodiment of the invention; Figure 18 is a side view of the damper of Figure 17; Figure 19 is a top-down view of the damper of Figure 17; Figure 20 is a cross-section of the damper of Figure 17; Figure 21 is a perspective view of a part-annular damper segment of the damper of Figure 5 in accordance with one embodiment of the invention; and Figure 22 is a perspective view of a part-annular damper segment of the damper of Figure 12 in accordance with one embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 3 shows schematically a vehicle 100 comprising a compression-ignition internal combustion engine 110. The internal combustion engine 110 comprises a fuel tank 120 configured to store low-pressure fuel, a plurality of cylinders 130 configured to combust high-pressure fuel, and a pump 200 configured to pressurise and pump fuel from the fuel tank 120 to the cylinders 130 for combustion.

The pump 200 comprises an inlet port 210 configured to receive low-pressure fuel from the fuel tank 120 and an outlet 215 configured to send pressurised fuel to the cylinders 130. An inlet valve 220, positioned between the inlet port 210 and the outlet 215, is configured to control the flow of fuel from the fuel tank 120 to the cylinders 130.

Figure 4 shows the pump 200 in detail, and reveals that the pump 200 comprises a lower or pump body 205, commonly referred to as a pump housing, and an upper body 204, commonly referred to as a hydraulic head.

The upper body 204 comprises a main section 209 and an elongate component 230 that extends downwardly from the main section 209 along a longitudinal axis L. The elongate component 230 also extends radially away from the longitudinal axis L along a radial axis R. The main section 209 houses the inlet port 210, the outlet 215 and the inlet valve 20 220.

In this example, the elongate component 230 takes the form of a turret having a plunger bore 208. The turret is substantially cylindrical, having a substantially circular cross-section in a plane perpendicular to the longitudinal axis L. The bore 208 houses a plunger 235 that is configured to reciprocate along the longitudinal axis L within the bore 208. The reciprocating movement of the plunger causes fuel to be drawn into the pump 200 via the inlet port 210 as the inlet valve 220 is opened and then pumped out of the pump 200 via the outlet 215. In this embodiment, the elongate component 230 is directly adjacent to, and extends longitudinally away from, the inlet valve 220 and the outlet 215, as in Figure 4.

In this example, the lower or pump body 205 surrounds the elongate component 230. To this end, the lower body 205 comprises a longitudinal cavity 202 shaped to receive the elongate component 230.

The lower body 204 comprises an annular cavity 240 that surrounds a part of the elongate component 230 around its entire circumference. The annular cavity 240 is continuous with the longitudinal cavity 202, such that the annular cavity 240 can be considered as a region of the longitudinal cavity 202 that is of increased radius. Many standard pumps 200 of internal combustion engines 110 already include such annular cavities 240 in their designs.

The annular cavity 240 is open at an upper surface of the lower body 205. In this way, when the upper and lower bodies 204, 205 are arranged together in the assembled pump 200, the cavity 240 is closed off by the lower body 204.

The upper body 204 and the lower body 205 are fixedly attached by a bolt 206 that extends through the main section 209 of the upper body 205 and the lower body 204 so as to connect the upper and lower body 204, 205 together.

The pump 200 further comprises a toroidal damper 300 arranged in the annular cavity 240. The damper 300 entirely surrounds the elongate component 230. A small spacing may advantageously be provided between the damper and the elongate component, to reduce damage that might otherwise occur from fretting.

The damper 300 is configured to absorb pressure pulsations that may arise in the pump 200. For example, as the pump 200 pumps fuel to the cylinder 130 for combustion, a sudden closure of the inlet valve 220 may result in such pressure pulsations in the pump 200. When the damper 300 is advantageously arranged in a cavity 240 around an elongate component 320 adjacent to the inlet valve 220, the damper 300 is effectively able to minimise such pressure pulsations, as will be later described.

The damper will now be described in more detail with reference to Figures 5 to 11, which show the damper in isolation.

Referring to Figures 5 to 9, the damper 300 comprises a generally annular body 302. An opening 304 is provided at the centre of the body 302 that extends longitudinally along the longitudinal axis L across the damper 300. In use, as shown in Figure 4, the elongate component 230 of the pump 200 extends through the opening 304.

The body defines an inner, or internal, annular wall 320 and an outer, or external, annular wall 325. In use, the inner wall 320 faces towards the elongate component 230, while the outer wall 325 faces the lower body 205. The inner and outer walls 320, 325 each extend substantially along the longitudinal axis L, and in this example each extend substantially linearly.

As best seen in Figure 8, the body 302 of the damper defines a chamber 330 between the inner and outer walls 320, 325, which contains a damping fluid for absorbing pressure pulsations. In this example, the damping fluid is an inert gas, such as is argon. The pressure of the gas is between approximately 1 bar and 5 bar, and preferably approximately 3 bar.

Considering the body 302 in more detail, as best seen in Figures 8 and 9, the body 302 comprises inner and outer annular parts 310, 315 that surround the elongate component 230. In this example, the inner and outer parts 310, 315 are formed from separate pieces that are fixedly attached to each other, for example by welding, though in other embodiments the inner and outer parts may be made of a single continuous piece. The inner and outer parts 310, 315 are preferably made of stainless steel, since stainless steel is relatively non-corrosive when exposed to fuel and is stiff and durable, though they may be made of any suitable material, such as a suitable metal or plastics material. Plastic inner and outer parts 310, 315 are cheap to manufacture, but are not as stiff and durable as stainless steel alternatives.

As best seen in Figures 10 and 11, which show the inner and outer parts 310, 315 in isolation, the inner part 310 defines the annular inner wall 320 and the outer part 315 defines the annular outer wall 325.

At their upper and lower ends, the inner and outer walls 320, 325 extend into generally transverse walls 340 that extend transversely (i.e. non-parallel) to the inner and outer walls 320, 325. The transverse sections 340 of the inner section 310 extend radially outwardly, and the transverse sections of the outer section 315 extend radially inwardly. As best seen in Figure 9, the transverse sections 340 therefore extend towards each other to define the top and bottom of the chamber 330. In this way, together, the inner and outer walls 320, 325 and the transverse sections 340 define the external walls of the chamber 330 in their entirety.

In this example, the transverse walls are not perpendicular to the inner and outer walls 320, 325, instead curve gradually towards each other. In particular, in a cross-sectional plane containing a radial axis R and the longitudinal axis L, the transverse walls 340 curve towards each other away from the longitudinal axis L and towards the radial axis R. As a result, the chamber 330 has a substantially elliptical cross-section in the plane containing the radial axis R and the longitudinal axis L. The transverse walls 340 terminate at flange sections 350 at the upper and lower ends of each of the inner and outer parts 310, 315. The flange sections 350 extend from the transverse sections 340 parallel to each other, and parallel to the longitudinal axis L. Each flange section 350 abuts and is fixedly attached, preferably by means of welding, to a corresponding flange section 350. Together, two fixedly attached flange sections 350 constitute a flange 360 of the damper 300. In this way, the damper 300 comprises a flange 360 at each, at which flange 300 the inner and outer parts 310, 315 are fixedly attached.

Figures 12 to 16 show another embodiment of the damper, which is substantially the same as the damper of Figures 5 to 11, except that the transverse sections 340 extend perpendicularly to the inner and outer walls 320, 325 along the radial axis R. As a result, the chamber 330 has a substantially rectangular cross-section in the plane containing the radial axis R and the longitudinal axis L. In the embodiment of Figures 12 to 16, each flange 360 of the damper 300 is located inside the chamber 330, in contrast to the embodiment of Figures 5 to 11, in which each flange 360 of the damper 300 is located outside the chamber 330.

While a damper 300 in which flanges 360 are arranged outside the chamber 330 may be easier to assemble, a damper 300 in which the flanges 360 are arranged inside the chamber 330 may be more compact, and hence may be arrangeable in a smaller cavity 240.

Another embodiment is shown in Figures 17 to 20, in which the inner and outer walls 320, 325 each undulate along the longitudinal axis L. Except for this feature, the embodiment of Figures 17 to 20 is substantially the same as the damper of Figures 5 to 11.

When the damper 300 is arranged in the pump 200 as shown in Figure 4, the damper minimises pressure pulsations by deforming as such pressure pulsations are transmitted through the pump 200. After such deformations, the damper 300 returns to its original shape and form, ready to absorb further pressure pulsations.

In doing so, the damper 300 absorbs the energy of the pressure pulsations, preventing the pressure pulsations from causing damage to the pump 200 or other systems in the internal combustion engine 110.

In more detail, pressure pulsations in the pump 200 cause the inner and outer parts 310, 315 of the damper 300 to be brought together and hence to compress the damping fluid (not shown) contained therein. In this way, the damper 300 absorbs the energy of the pressure pulsations. The damping fluid then applies pressure forces against the inner and outer parts 310, 315 forcing the damper 300 to return to its initial state.

By virtue of the arrangement of the inner and outer parts 310, 315 around the elongate component 230 and the damping fluid (not shown) between the inner and outer walls 320, 325, the damper 300 is configured to deform radially along the radial axis.

In one particularly preferred embodiment, the inner and outer walls 320, 325, and hence the chamber 330, are elongate along the longitudinal axis L. The longer the inner and outer walls 320, 325, the more adept the damper 300 can be at absorbing pressure pulsations in the pump 200. This is because there can be greater absorption surface of the damper 300 along the elongate inner wall 320 and because the damper 300 comprises a greater volume of fluid pressure for absorbing pressure pulsations.

A method of making the damper 300 and the pump 200 described above is now 30 described.

The damper 300 is first assembled. In a pressurised chamber, the inner part 310 is arranged inside the outer part 315 such that the flange sections 350 are in contact. Because assembly takes place in a pressurised chamber, as the chamber 330 is created it is filled with the pressurised gas, which forms the damping fluid.

Still in the pressurised chamber, the flange sections 350 are welded together so as to seal the chamber 330.

Referring to Figure 4, the damper 300 is then installed in the pump 200.

In this example, the upper body 204 and the lower body 205 are initially provided unattached and separate from one another. The upper body 204 comprises the elongate component 230 and the lower body 205 comprises an open annular cavity 240.

To install the toroidal damper 300 in the pump 200, the damper 300 is arranged around the elongate component 230 by pushing the opening 304 of the damper 300 over the elongate component 230. Then, the elongate component 230 is arranged into the longitudinal cavity 202 of the lower body 205, for example by lowering the upper body 204 onto the lower body 205. The upper body 204 is lowered until the damper 300 is located in the annular cavity 240, and until the upper body 204 closes the annular cavity 240.

In an alternative installation method, the toroidal damper 300 is first arranged in the annular of the lower body 205. Next, the elongate component 230 is threaded through the opening 304 of the damper 300 and into the longitudinal cavity 202, for example by lowering the upper body 204 through the damper 300 and onto the lower body 205. The upper body 204 is lowered until the upper body 204 closes the annular cavity 240.

After this assembly, the damper 300 is enclosed in the annular cavity 240 between the upper body 204 and the lower body 205. The bolt 206 is then passed through the main section 209 of the upper body 204 and the lower body 205, thus fixedly attaching the upper body 204 and the lower body 205, and completing the installation process.

So as to assist with arranging the assembly of the damper 300 around the elongate component 230, the damper 300 may be made up of a plurality of part-annular damper segments 370. Figures 21 and 22 show two such damper segments. In these examples, each damper segment is semi-toroidal, extending through 180°, such that two damper segments are required to form a fully toroidal damper 300.

In this case, the damper 300 further comprises a fixing means for fixing the segments together.

The fixing means may take the form of a curved biasing means (not shown), such as a wire loop, snap ring or circlip, configured to hold the damper segments 370 in place in place in the cavity 240. To this end, the curved biasing means is configured to wrap tightly around the outer wall 325 of the damper 300, i.e. around an outer segment wall 375 of each damper segment 370. The curved biasing means may extend around an entire circumference of the outer wall 325 of the damper 300, or may be part-annular or crescent-shaped instead. The flanges 360 of the damper 300 may comprise a groove (not shown) that accommodates the biasing means. Alternatively or additionally, the wall of the annular cavity may comprise a groove that accommodates the biasing means. In other embodiments, the fixing means may be provided as co-operating engagement features on the ends of the damper segments 370.

To arrange the segmented damper 300 around the elongate component 230 in the open cavity 240, the damper segments 370 are arranged in the open cavity 240 of the pump 200 around the elongate component 230. The segments are fixed together using the fixing means: For example, the curved biasing means (not shown) is wrapped around the outer segment wall 375 of each damper segment 370. In doing so, the damper 300 is assembled around the elongate component 230 and the damper 300 is fixed in place. The lower body 205 can then be arranged in position for attachment of the upper body 204.

It will be appreciated by those skilled in the art that the invention has been described by way of example only, and that a variety of alternative approaches may be adopted. These and other variations are possible without departing from the scope of the invention as defined by the appended claims.

For example, the pump may be a pump for an internal combustion engine 110 in the form of a diesel engine or a petrol engine.

Embodiments are envisaged in which the damper is part-toroidal and comprises part-annular inner and outer walls. That is, the damper may be crescent-shaped.

The damper may then only partially surround the elongate component, and the cavity may be part-annular and only partially surround the elongate component. Instead of entirely surrounding the elongate component, the inner wall of the damper may only surround a part of the elongate component 230.

While such a part-toroidal damper 300 may be less efficient at minimising pressure pulsations in the pump 200, it has the advantage of taking up less space. Such part-toroidal dampers 300 also are easier to assembly in the cavity 240.

In the embodiment shown, the pump is a Digital Interface Valve (DIV) pump, but the pump may also take the form of an Inlet Metering Valve (IMV) pump, or any other suitable pump that requires damping. The elongate component that is surrounded by the damper may be any suitable component and need not necessarily be the turret. For example, in other embodiments, the elongate component 230 may take the form of the inlet port 210, an inlet connector, or a drive shaft in the cambox.

Reference numbers Vehicle 100 Internal combustion engine 110 Fuel tank 120 Cylinders 130 Pump 200 Longitudinal cavity 202 Upper body 204 Lower body 205 Bolt 206 Plunger bore 208 Main section of the upper body 209 Inlet port 210 Outlet 215 Inlet valve 220 Elongate component 230 Plunger 235 Cavity 240 Damper 300 Body of the damper 302 Opening 304 Inner part 310 Outer part 315 Inner wall 320 Outer wall 325 Chamber 330 Transverse sections 340 Flange sections 350 Flange 360 Damper segment 370 Outer segment wall 375

Claims

CLAIMS: 1. A pump (200) for an internal combustion engine (110); the pump (200) comprising: an elongate component (230) extending longitudinally along a longitudinal axis (L) and radially away from the longitudinal axis (L) along a radial axis (R); a pump body (205) at least partially surrounding the elongate component (230), the pump body (205) comprising an annular or part-annular cavity (240) at least partially surrounding the elongate component (230); and a toroidal or part-toroidal damper (300) for absorbing pressure pulsations in the pump (200), the damper (300) being arranged in the cavity (240) to at least partially surround the elongate component (230), and comprising inner and outer annular or part-annular walls (320, 325) and a chamber (330) between the inner and outer walls (320, 325), the chamber (330) containing a damping fluid, wherein the inner wall (320) surrounds at least a part of the elongate component (230).
2. The pump (200) of claim 1, wherein the damper (300) is configurable to deform radially along the radial axis (R).
3. The pump (200) of claim 1 or claim 2, wherein: the cavity (240) is annular and entirely surrounds the elongate component (230); the damper (300) is toroidal and comprises inner and outer annular walls (320, 325); and the inner wall (320) entirely surrounds the elongate component (230).
4. The pump (200) of any preceding claim, wherein the inner and outer walls (320, 325) are elongate along the longitudinal axis (L).
5. The pump (200) of any preceding claim, wherein the chamber (330) has a substantially elliptical or rectangular cross-section in a plane containing the longitudinal axis (L) and the radial axis (R).
6. The pump (200) of any preceding claim, wherein the damper (300) comprises inner and outer parts (310, 315), the inner part (310) comprising the inner wall (320) and the outer part (315) comprising the outer wall (325), and the inner and outer parts (310, 315) being fixedly attached.
7. The pump (200) of claim 6, wherein the inner and outer parts (310, 315) comprise a flange (360) at each end of the inner and outer parts (310, 315) at which the inner and outer parts (310, 315) are fixedly attached.
8. The pump (200) of claim 7, wherein each flange (360) is located inside the chamber (330) or outside the chamber (330).
9. The pump (200) of any preceding claim, wherein the damper (300) is made up of at least two part-annular damper segments and the damper (300) comprises at least one fixing means to fix the damper segments together around the elongate component (230).
10. The pump (200) of any preceding claim, wherein the damping fluid is a gas, and the gas is preferably an inert gas.
11. An internal combustion engine (110) comprising the pump (200) of any preceding claim.
12. A vehicle (100) comprising the internal combustion engine (110) of claim 12.
13. A method of making a pump (200) for an internal combustion engine (110), the method comprising: providing a pump (200) comprising an elongate component (230) and a pump body (205) surrounding the elongate component (230); providing a toroidal or part-toroidal damper (300) for absorbing pressure pulsations in the pump (200), wherein the damper (300) comprises inner and outer annular or part-annular walls (320, 325) and a chamber (330) between the inner and outer walls (320, 325), and the chamber (330) contains a damping fluid; and arranging the damper (300) in an annular or part-annular cavity (240) of the pump body (205), the cavity (240) at least partially surrounding the elongate component (230), such that the inner wall (320) of the damper (300) surrounds at least a part of the elongate component (230).
14. The method of claim 13, wherein the cavity (240) is open at a face of the pump body (205), wherein the pump comprises a further body (204), the further body (204) supporting the elongate component (230); and wherein the step of arranging the damper (300) in the cavity (240) comprises effecting relative movement between the further body (204) and the pump body (205) to pass the elongate component (230) through the cavity (240) until the further body (204) closes the cavity (240).
15. The method of claim 13 or claim 14, wherein the damper (300) includes at least two damper segments and a fixing means, and the step of providing the damper (300) comprises providing the at least two damper segments and fixing the segments together using the fixing means.