AXIALLY SPLIT BEARING HOUSING AND A ROTARY MACHINE

Abstract

 An axially split bearing housing is proposed for receiving the non-drive end of a shaft (110) of a rotary machine (100), the bearing housing extending in an axial direction (A) from an inboard end (41) to an outboard end (42), and comprising an upper housing part (2) and a lower housing part (3) designed for being fixedly connected to each other, and further comprising a disk-shaped end cover (6) for closing the bearing housing at the outboard end (42) in the axial direction (A), wherein the upper housing part (2), the lower housing part (3) and the end cover (6) are designed to engage with each other for fixedly connecting the end cover (6) to the upper and the lower housing part (2, 3) in a boltless manner. In addition, a rotary machine having such a bearing housing is proposed.

Description

[0001] The invention relates to an axially split bearing housing for receiving the non-drive end of a shaft of a rotary machine and to a rotary machine for acting on a fluid in accordance with the preamble of the respective independent claim.

[0002] Rotary machines for acting on a fluid, for example centrifugal pumps, compressors, blowers, expanders or turbines, typically comprise a stationary machine casing enclosing a rotor, e.g. an impeller, for interacting with the fluid and a shaft for rotating the rotor about an axial direction. The shaft can be driven by a drive unit. The end of the shaft that is connected to the drive unit is also referred to as the drive end of the shaft, whereas the other end of the shaft is referred to as non-drive end of the shaft. The rotary machine further comprises at least one bearing unit with a radial and/or an axial (thrust) bearing for supporting the shaft and the rotor. Typically the bearing has a separate housing which is fixedly connected to the casing of the rotary machine. Since the bearings usually require lubrication and/or cooling a lubricant, for example an oil or any other suited fluid, is supplied to the bearing unit. In many applications this lubricant shall neither leak from the bearing unit into the environment nor get into contact with the fluid the rotary machine is acting on to avoid any contamination of this fluid or the environment with the lubricant.

[0003] In particular in centrifugal pumps but also in other rotary machines two basic principles are known for supporting the shaft, namely to support the shaft only on one side of the rotor or the impeller; or to support the shaft on both sides of the rotor or the impeller. According to the design where only one end of the shaft is supported - usually this is the drive end of the shaft - the rotor or the impeller is usually arranged at the non-drive end of the shaft. This design is also called "overhung" design. If both the drive end and the non-drive end of the shaft are supported by a respective bearing, the impeller or the rotor is arranged between the two bearing units. Therefore this embodiment is also called "between bearing" design.

[0004] The invention is related to this between bearing design and in particular to the bearing housing arranged at the non-drive end of the shaft. This bearing housing has an inboard end facing the rotary machine and an outboard end facing away from the rotary machine. The shaft enters the bearing housing through the inboard end and ends within the bearing housing, meaning that the outboard end of the bearing housing has to be closed with respect to the axial direction.

[0005] To close the bearing housing at its outboard end it is known to attach an end cover to the bearing housing. The end cover is fixed with respect to the housing by a plurality of screws or bolts extending through the end cover in the axial direction. Additionally, this end cover may be used to position and to support the thrust bearing being arranged within the bearing housing. However, this known design requires a plurality of screws and bolts for fixing the end cover, which is quite expensive. In addition, the mounting or the dismounting of the end cover is laborious and requires a lot of time.

[0006] Starting from this state of the art it is therefore an object of the invention to propose a bearing housing for receiving the non-drive end of a shaft of a rotary machine which is simpler from the constructional perspective, more cost-efficient, and easier to assemble. Concurrently, the bearing housing shall be safe and reliable during operation. It is a further object of the invention to propose a rotary machine having such a bearing housing.

[0007] The subject matter of the invention satisfying these objects is characterized by the features of the respective independent claim.

[0008] Thus, according to the invention an axially split bearing housing is proposed for receiving the non-drive end of a shaft of a rotary machine, the bearing housing extending in an axial direction from an inboard end to an outboard end, and comprising an upper housing part and a lower housing part designed for being fixedly connected to each other, and further comprising a disk-shaped end cover for closing the bearing housing at the outboard end in the axial direction, wherein the upper housing part, the lower housing part and the end cover are designed to engage with each other for fixedly connecting the end cover to the upper and the lower housing part in a boltless manner.

[0009] Designing the two housing parts and the end cover such that they engage with each other renders possible to directly clamp the end cover between the upper and the lower housing part. Therefore any bolts or screws for securing the end cover can be avoided. This makes the design of the end cover much simpler. The lack of any bolts or screws at the end cover for mounting the end cover to the housing parts also reduces the overall costs of the bearing housing as well as the time and the expenditure of work for assembling or disassembling the bearing housing. The end cover reliably seals the bearing housing therewith ensuring a safe operation.

[0010] According to a preferred embodiment, the outer rim of the end cover comprises a tongue extending in a radial direction, and the upper housing part and/or the lower housing part comprise a groove for engaging with the tongue. The cooperation of the tongue and the groove adapted to receive the tongue ensures a safe connection between the end cover and the two housing part and additionally fixes the end cover's position regarding the axial direction relative to the two housing parts.

[0011] Regarding this embodiment it is particularly preferred if the tongue extents essentially along the entire circumference of the end cover. Correspondingly, both the upper and the lower housing part are each provided with a groove that extends along the entire respective housing part with respect to the circumferential direction. Thus, when the upper and the lower housing part are fixed to each other said two grooves form an essentially annular groove for receiving the tongue of the end cover. Thereby the end cover is clamped between the upper and the lower housing parts by means of the tongue engaging with the annular groove in the two housing parts.

[0012] As an alternative it is also possible to provide the tongue or the tongues at the upper and/or the lower housing part and to provide the outer rim of the end cover with a groove adapted for receiving said tongue(s).

[0013] It is a preferred measure, that the tongue comprises a notch, and the upper housing part or the lower housing part comprise a pin for engaging with the notch to prevent a relative rotational movement between the end cover and the upper and the lower housing part. By the engagement of the pin, e.g. a dowel pin, with the notch in the tongue any rotation of the end cover with respect to the upper and the lower housing part is reliably prevented, i.e. the angular position of the end cover is securely fixed.

[0014] In order to ensure a reliable sealing between the end cover and the two housing parts it is preferred, that the outer rim of the end cover comprises a slot for receiving a sealing element, said slot extending along the entire circumference of the end cover. Preferably a sealing element such as an O-ring is inserted into the slot for providing the sealing action. Regarding the position of the slot with respect to the axial direction it is advantageous to provide the slot for the sealing element on that side of the tongue that faces away from the outboard end of the bearing housing, i.e. the tongue is located between the slot and the outboard end.

[0015] Preferably the end cover comprises a centrally arranged hole for receiving a locking device for the shaft. Thereby it is possible to secure the shaft, for example against rotation, during transportation or assembly of the rotary machine. During operation of the rotary machine the hole in the end cover may be sealingly closed by a plug or any other appropriate means.

[0016] According to another embodiment, the outer rim of the end cover comprises a plurality of tongues extending in the radial direction, and the upper housing part and/or the lower housing part comprise a plurality of grooves, each groove being adapted for engaging with one of the tongues. The individual tongues are aligned with respect to the circumferential direction of the end cover. For each of the individual tongues a respective groove is provided in the upper or the lower housing part for receiving the tongue. The length of the respective groove as measured in the circumferential direction corresponds to the length of the individual tongue in the circumferential direction, so that each tongue closely fits into the respective groove. The length of the individual tongues in the circumferential direction may be the same for all tongues but may also be different for the individual tongues.

[0017] According to a preferred embodiment the upper housing part and the lower housing part each comprise a flange at its respective outboard end, each of said flanges extending radially inwardly, meaning that the diameter of the end cover is smaller than the diameter of the outboard end of the bearing housing. This design enables a particularly safe and reliable connection between the end cover and the two housing parts. In addition, the flanges may be used as support for a thrust bearing arranged in the bearing housing, i.e. the flanges may absorb the mechanical forces acting upon the thrust bearing during operation.

[0018] From a constructional perspective it is preferred that each flange is integrally formed in one piece with the respective housing part.

[0019] According to a preferred embodiment the bearing housing comprises a first annular chamber for receiving a radial bearing for the shaft.

[0020] It is also preferred, when the bearing housing comprises a second annular chamber for receiving a thrust bearing for the shaft. Most preferred the bearing housing has both the first chamber for receiving the radial bearing and the second chamber for receiving the thrust bearing. This is a very compact design for housing the radial (or journal) bearing as well as the thrust (or axial) bearing for the shaft of a rotary machine. With respect to the axial direction the second chamber is arranged behind the first chamber such that the first chamber is closer to the inboard end of the bearing housing and the second chamber is closer to the outboard end of the bearing housing.

[0021] In order to provide a reliable support for the thrust bearing during operation of the rotary machine it is preferred that the second annular chamber is delimited by the flange of the upper housing part and by the flange of the lower housing part.

[0022] In addition, according to the invention a rotary machine is proposed for acting on a fluid, comprising a shaft having a drive end as well as a non-drive end, and further comprising an axially split bearing housing in accordance with the invention for receiving the non-drive end of the shaft.

[0023] In view of important applications, the rotary machine is a pump, in particular a centrifugal pump. The centrifugal pump may be designed for example as a boiler feed pump or as a booster pump or as an injection pump for seawater or water injection or as a pump for moving oil or crude oil through a pipeline.

[0024] Further advantageous measures and embodiments of the invention will become apparent from the dependent claims.

[0025] The invention will be explained in more detail hereinafter with reference to embodiments of the invention and to the drawings. There are shown in a schematic representation:

Fig. 1:

a cross-sectional schematic view of an embodiment of a rotary machine according to the invention,

Fig.2:

a perspective view of a first embodiment of an axially split bearing housing according to the invention,

Fig. 3:

the embodiment of Fig. 3 in a perspective cross-sectional view,

Fig. 4:

a plan view of the end cover of the bearing housing in Fig. 3,

Fig. 5:

a cross-sectional view of the end cover in a cut along line V-V in Fig. 4,

Fig. 6:

a variant for preventing rotation of the end cover, and

Fig. 7:

an illustration of a second embodiment of a bearing housing according to the invention.

[0026] In the following description reference is made by way of example to an important application, namely that the rotary machine is designed as a centrifugal pump.

[0027] Fig. 1 shows a cross-sectional view of an embodiment of a rotary machine according to the invention which is designated in its entity with reference numeral 100. The embodiment of the rotary machine 100 is a centrifugal pump 100 for conveying a fluid, for example water or crude oil or a multiphase fluid.

[0028] It goes without saying that the invention is neither restricted to the centrifugal pump 100 illustrated in Fig. 1 nor to centrifugal pumps as such but is related to rotary machines 100 in general. By way of example the rotary machine 100 may also be another type of pump, a compressor, a blower, an expander or a turbine.

[0029] The centrifugal pump 100 comprises a casing 101 that may consist of a plurality of casing parts, which are connected to each other to form the casing 101. The casing 101 of the centrifugal pump 100 comprises an inlet 102, through which the fluid to be conveyed enters the pump 100 and an outlet 103 for discharging the fluid. Inside the casing 101 at least one impeller 104 is provided for acting on the fluid. The embodiment shown in Fig. 1 is designed as a multistage pump having a plurality of impellers 104, here five impellers 104. All impellers 104 are mounted in series on a shaft 110 in a torque proof manner. By means of the shaft 110 the impellers 104 are driven during operation of the pump 100 for a rotation about an axial direction A that is defined by the longitudinal axis of the shaft 110. In Fig. 1 the flow of the fluid is indicated by the arrows without reference numeral.

[0030] A direction perpendicular to the axial direction A is referred to as 'radial direction'. The term 'axial' or 'axially' is used with the common meaning 'in axial direction' or 'with respect to the axial direction'. In an analogous manner the term 'radial' or 'radially' is used with the common meaning 'in radial direction' or 'with respect to the radial direction'.

[0031] The shaft 110 is driven by means of a drive unit (not shown), for example an electric motor or any other type of motor, to which the shaft 110 is coupled. The end of the shaft 110 that is coupled to the drive unit is designated as drive end 111 of the shaft, whereas the other end of the shaft 110 is designated as non-drive end 112. According to the representation in Fig. 1 the drive end 110 that is connected to the drive unit (not shown) is located on the left side.

[0032] Starting from the drive end 111 of the shaft 110 and moving towards the non-drive end 112 the pump 100 comprises the following components: A drive end bearing housing 115 accommodating a radial (or journal) bearing 116; a mechanical seal 117 for sealing the pump 100 against leakage of the fluid along the shaft 110; the plurality of impellers 104; a balancing drum 118 for balancing the axial thrust generated by the impellers 104; another mechanical seal 119 for sealing the non-drive side of the shaft 110 against leakage of the fluid to be pumped; and a non-drive end bearing housing 1 accommodating a further radial (or journal) bearing 120 and a thrust (or axial) bearing 121 for supporting the non-drive end 112 of the shaft 110 with respect to the radial direction and the axial direction A, respectively.

[0033] Thus, the centrifugal pump 100 is designed as a between bearing pump having bearings 116, 120, 121 on both sides of the plurality of impellers 104, i.e. at the drive end 111 of the shaft 110 as well as at the non-drive end 112 of the shaft 110.

[0034] The bearing housing 1 arranged at the non-drive end 112 of the shaft 110 is designed according to the invention. The bearing housing 1 will now be explained in more detail referring to embodiments of the bearing housing 1 for receiving the non-drive end 112 of the shaft 110.

[0035] Fig. 2 shows a perspective view of a first embodiment of the bearing housing 1 according to the invention for receiving the non-drive end 112 of the shaft 110 of the rotary machine 100. For a better understanding Fig. 3 shows this bearing housing 1 in a perspective cross-sectional view.

[0036] The bearing housing 1 that is designated in its entity with reference numeral 1 has an essentially cylindrical shape for surrounding the shaft 110 of the centrifugal pump 100. The bearing housing 1 is designed as an axially split bearing housing 1 having an upper housing part 2 and a lower housing part 3. As typically used in the art the term "axially split" means that the bearing housing 1 is divided along the axial direction A or in other words, divided parallel to the shaft 110, which is surrounded by the bearing housing 1 during operation.

[0037] Each of the upper housing part 2 and the lower housing part 3 extends in the axial direction A from an inboard end 41 to an outboard end 42 of the bearing housing 1. The inboard end 41 of the bearing housing 1 is that end of the bearing housing 1, which faces the centrifugal pump 100 when the bearing housing 1 is attached to the centrifugal pump 100 (see Fig. 1). The outboard end 42 of the bearing housing 1 is that end of the bearing housing 1, which faces away from the centrifugal pump 100 when the bearing housing 1 is attached to the centrifugal pump 100.

[0038] The upper housing part 2 and the lower housing part 3 are configured for being fixedly connected to each other. For this purpose each of the upper housing part 2 and the lower housing part 3 comprises a lateral flange 21 and 31, respectively, having a plurality of pairwise aligned bores 23 for receiving bolts or nuts 231 by means of which the upper housing part 2 and the lower housing part 3 are securely fixed to each other. Both the upper housing part 2 and the lower housing part 3 have an essentially semicylindrical shape.

[0039] The inboard end 41 of the bearing housing 1 is configured as a mounting flange 5 for fixing the bearing housing 1 to the casing 101 of the centrifugal pump 100 (see Fig. 1). The mounting flange 5 comprises a plurality of bores 51 for receiving screws or bolts by means of which the bearing housing 1 may be secured to the casing 101 of the centrifugal pump 100.

[0040] At the outboard end 42 the upper housing part 2 comprises a flange 24 extending radially inwardly such that the flange 24 forms a part of the outboard end 42 of the bearing housing 1. In an analogous manner the lower housing part 3 comprises a flange 34 extending radially inwardly such that the flange 34 forms a part of the outboard end 42 of the bearing housing 1. Both flanges 24 and 34 are preferably formed integrally in one piece with the respective housing part 2, 3.

[0041] When the upper housing part 2 and the lower housing part 3 are assembled they form a part of the outboard end 42 of the bearing housing 1, however they leave an essentially circular opening 7 which is arranged centrally around the axial direction A and delimited by the flange 24 of the upper housing part 2 as well as by the flange 34 of the lower housing part 3.

[0042] The bearing housing 1 further comprises a generally disk-shaped end cover 6 for closing the circular opening 7 in the outboard end 42 of the bearing housing 1. The disk-shaped end cover 6 is arranged perpendicular to the axial direction A at the outboard end 42, such that it closes the bearing housing 1 with respect to the axial direction A.

[0043] According to the invention the upper housing part 2, the lower housing part 3 and the end cover 6 are designed to engage with each other for fixedly connecting the end cover 6 to the upper housing part 2 and the lower housing part 3 in a boltless manner.

[0044] In the embodiment illustrated in Fig. 2 and Fig. 3 the engagement between the housing parts 2, 3 and the end cover 6 is realized by a tongue and groove design which will be explained in more detail.

[0045] For a better understanding Fig. 4 shows a plan view of the end cover 6 of the bearing housing 1. In addition, Fig. 5 shows a cross-sectional view of the end cover 6 in a cut taken along cutting line V-V in Fig. 4.

[0046] As can be best seen in Fig. 5 the essentially disk-shaped end cover 6 has an outer rim 61 delimiting the end cover 6 with respect to the radial direction. The outer rim 61 comprises a tongue 62 extending in the radial direction as a protrusion. In addition, the tongue 62 is extending in the circumferential direction essentially along the entire circumference of the end cover 6. The tongue 62 is provided with a notch 63 forming a small gap in the tongue 62 for receiving a pin 81 (see Fig. 3) engaging with the notch 63 to prevent rotation of the end cover 6.

[0047] The outer rim 61 is further provided with a slot 64 for receiving a sealing element, preferably an O-ring, which seals the end cover 6 with respect to the upper and lower housing part 2, 3 in a liquid tight manner, so that no liquid can leak between the end cover 6 and the upper or lower housing part 2, 3, respectively. The slot 64 is designed as an annular slot 64 extending along the entire circumference of the end cover 6. The slot 64 is extending essentially parallel to the tongue 62 and located with respect to the axial direction A more inwardly than the tongue 62, such that the tongue 62 is located between the slot 64 and the outboard end 42 in the assembled state.

[0048] As can be best seen in Fig. 3 both the upper housing part 2 and the lower housing part 3 respectively comprise a groove 8 for engaging with the tongue 62 of the end cover 6. More particularly, the grooves 8 are provided in that surface of the respective flange 24, 34 of the upper and the lower housing part 2, 3, which delimits the central opening 7. In the assembled state of the upper and the lower housing part 2, 3 the grooves 8 complement one another to form an annular groove 8 extending along the entire circumference of the bounding surface delimiting the central opening 7.

[0049] Within the groove 8 the pin 81 is provided for engaging with the notch 63 in the tongue 62 of the end cover 6.

[0050] The tongue 62 and the annular groove 8 are designed to closely fit into one another in the assembled state.

[0051] According to a preferred embodiment the end cover 6 further comprises a centrally arranged hole 65 for receiving a locking device (not shown) for the shaft 110. The circular hole 65 is arranged in the center of the end cover 6 so that the locking device may be inserted through the end cover 6 for contacting the non-drive end of the shaft 110 when the bearing housing 1 is mounted to the non-drive end 112 of the shaft 110. The locking device shall prevent any undesired motion of the shaft 110 in particular during transportation, assembly or installation of the centrifugal pump 100. The locking device as such is well known in the art and therefore does not require additional explanations. It is inserted through the hole 65 and engages the shaft 110 within the bearing housing 1 for securing the shaft.

[0052] It goes without saying that the locking device is removed prior to putting the pump 100 into operation. When the locking device has been removed, the hole 65 in the end cover is sealingly closed, for example by a plug or a cover or a similar means.

[0053] As can be best seen in Fig. 3 the bearing housing 1 comprises a first annular chamber 11 for accommodating the radial bearing 120 (Fig. 1) that supports the non-drive end 112 of the shaft 110 with respect to the radial direction. The radial bearing 120 is also referred to as journal bearing. In addition, the bearing housing 1 comprises a second annular chamber 12 for receiving the thrust bearing 121 (Fig. 1) that supports the shaft 110 with respect to the axial direction A. The thrust bearing 121 is also referred to as axial bearing. The first annular chamber 11 and the second annular chamber 12 are arranged in series inside the bearing housing 1 with respect to the axial direction A in such a way that the first annular chamber 11 is closer to the inboard end 41 and the second annular chamber 12 is closer to the outboard end 42 of the bearing housing 1.

[0054] As a particularly preferred measure the second annular chamber 12 for receiving the thrust bearing 121 is arranged such that it is delimited by the flanges 24 and 34 of the upper and lower housing part 2, 3. Thereby the flanges 24 and 34 provide support to the thrust bearing 121 with respect to the axial direction A and may absorb the axial forces acting on the thrust bearing 121. Different from the designs known in the art, the end cover 6 is not loaded with axial forces from the thrust bearing 121. According to said known designs the end cover is usually used to position and to support the side of the thrust bearing facing the outboard end. According to the preferred embodiment shown in Fig. 2 and Fig. 3 the second annular chamber 12 for the thrust bearing 121 is arranged in such a manner, for example by machining it into the bearing housing 1, that the second annular chamber 12 is delimited at the outboard end 42 by the flanges 24 and 34. During operation the flanges 24 and 34 provide support to the thrust bearing 121, whereas the end cover 6 has the main function to sealingly close the outboard end 42 of the bearing housing 1, but has not to provide any essential support to the thrust bearing 121.

[0055] In addition, the bearing housing 1 may comprise other components which are as such known in the art, for example a breather 9 (Fig. 2), or internal channels 91 for a lubricant or a coolant such as a lubricating oil.

[0056] For assembling the bearing housing 1 a sealing element, preferably an O-ring seal, is inserted into the slot 64 of the end cover 6. After that, the disk-shaped end cover 6 is inserted in one of the upper or lower housing part 2, 3 for example in the lower housing part 3, such that the tongue 62 engages with the groove 8 in the lower housing part 2, i.e. the tongue 62 is inserted into the groove 8 which tight-fittingly receives the tongue 62. In addition, the pin 81 engages with the notch 63 in the tongue 62. Then, the upper housing part 2 is laid upon the lower housing part 3 such that the tongue 62 is inserted into the groove 8 in the upper housing part 2 and that the lateral flanges 21 and 31 of the upper and lower housing part 2, 3 are facing each other. By inserting screws or bolts 231 into the bores 23 in the lateral flanges 21, 31 and tightening said screws or bolts the bearing housing 1 is closed and the upper housing part 2 is fixedly connected with the lower housing part 3.

[0057] Hence, the end cover 6 is fixedly connected to the bearing housing 1 in a boltless manner, meaning that there are no bolts or screws provided at the end cover 6 or passing through the end cover 6 for the fixation of the end cover 6 to the bearing housing. By connecting and securing the upper housing part 2 to the lower housing part 3 the end cover 6 is clamped between these two housing part 2, 3 and there is no need to provide any screws or bolts or similar fixing means at the end cover 6. The axial position of the end cover 6 is restrained by the engagement of the tongue 62 with the groove 8. In addition, any rotation of the end cover 6 relative to the bearing housing 1, i.e. relative to the upper and the lower housing part 2, 3 is prevented through the pin 81 in the groove 8 that engages with the notch 63 in the tongue 8. The sealing element, for example the O-ring, inserted into the slot 64 of the end cover 6 provides a reliable sealing action between the end cover 6 and the housing parts 2, 3, so that no liquid, for example the lubricant or the coolant for the radial bearing 120 or the thrust bearing 121, can leak between the end cover 6 and the upper and lower housing part 2, 3.

[0058] By avoiding any screws or bolts passing through the end cover 6 for fixing the end cover 6 to the bearing housing 1 the constructional effort is considerably reduced. In addition, the manufacturing as well as the assembly of the bearing housing 1 becomes much simpler, faster and more cost-efficient. In particular, the time to assemble and therewith the cost related to the assembly is remarkably reduced.

[0059] Instead of the optional pin 81 engaging with the notch 63 different designs may be provided to prevent a rotation of the end cover 6 about the axial direction A. It is for example possible to dispense with the pin 81 and the notch 63 in the tongue 62, i.e. the tongue 62 extends along the entire circumference of the outer rim 61 of end cover 6 without any gap in the tongue 62. Rotation of the end cover 6 about the axial direction A is then prevented by the clamping of the end cover 6 between the upper and the lower housing part 2, 3.

[0060] Another variant to prevent a rotation of the end cover 6 about the axial direction A in the mounted state is illustrated in Fig. 6. Fig. 6 shows the end cover 6 in the mounted state with the tongue 62 of the end cover 6 engaging with the groove 8 in the upper housing part 2, more particular in the flange 24 of the upper housing part 2. A sealing element, namely an O-ring 641 is inserted into the slot 64. For providing rotation of the end cover 6 about the axial direction A a screw 81' or a dowel screw 81' or a similar element is provided at the axial end surface delimiting the flange 24 at the outboard end 42. The screw 81' is arranged in such a manner that it extends into the tongue 62 engaging with the groove 8 in the flange 24. The screw 81' preferably ends within the tongue 62 and performs essentially the same function as the pin 81 described above. The engagement of the screw 81' with the tongue 62 prevents any rotation of the end cover 6 about the axial direction.

[0061] Of course, other configurations or designs are possible to prevent a rotation of the end cover, if necessary.

[0062] Fig. 67 illustrates a second embodiment of the bearing housing 1 according to the invention. In the following description only the differences to the first embodiment are explained. The explanations with respect to the first embodiment are also valid in analogously the same way for the second embodiment shown in Fig. 7. The reference numerals have the same meaning as already explained hereinbefore.

[0063] Fig. 7 shows a plan view of the end cover 6 and (partially) the upper and lower housing part 2, 3. For a better understanding Fig. 7 illustrates the state where the housing parts 2, 3 and the end cover 6 are not yet assembled. The housing parts 2, 3 are only indicated schematically.

[0064] Different from the first embodiment, the outer rim 61 of the end cover 6 of the second embodiment comprises a plurality of tongues 62, each extending in the radial direction. The individual tongues 62 have a lengths L in the circumferential direction of the end cover 6. All the tongues 62 are aligned with respect to the circumferential direction of the end cover 6. According to the representation in Fig. 7 the outer rim 61 of the end cover 6 is provided with four tongues 62. It has to be understood that the number of four tongues 62 is only an example. Of course, the number of tongues 62 may be smaller than four, for example only two or three tongues 62 may be provided at the outer rim 61, or the number of tongues 62 may be larger than four, for example six or eight or even more tongues 62 may be provided at the outer rim 61. The length L of the tongues 62 in circumferential direction may be the same for each of the tongues 62, or the length L may be different for different tongues 62. Furthermore, the distance between adjacent tongues 62 measured in the circumferential direction may be the same for each pair of adjacent tongues 62, or said distance may be different for different pairs of adjacent tongues 62.

[0065] The embodiment shown in Fig. 7 has four tongues 62 at the outer rim 61, which are equidistantly distributed along the circumference of the outer rim 61. All tongues 62 have the same length L in the circumferential direction.

[0066] The upper housing part 2 and/or the lower housing part 3 comprise a plurality of grooves 8, each groove 8 being adapted for engaging with one of the tongues 62. The grooves 8 are indicated in Fig. 7 by dashed lines because they are not visible in this plan view. The total number of grooves 8 in the upper housing part 2 and in the lower housing part 3 equals the number of tongues 62 at the outer rim 6.Thus, for each of the individual tongues 62 a respective groove 8 is provided in the upper or the lower housing part 2, 3 for receiving the respective tongue 62. The length of the respective groove 8 as measured in the circumferential direction preferably corresponds to the length L of the individual tongue 62 that engages with the groove in the assembled state. Thus, each tongue 62 closely fits into the respective groove 8.

[0067] The design with a plurality of tongues 62 engaging with a plurality of grooves 8 prevents a rotation of the end cover 6 about the axial direction A in the mounted state. The optional pin 81, e.g. a dowel pin, engaging with the notch 63 in one of the tongues 62 or the screw 81' (Fig. 6) for securing the end cover 6 against rotation may be dispensed with. Due to the plurality of tongues 62 and grooves 8 the end cover 6 is reliably prevented from a rotation relative to the upper and lower housing part 2, 3.

[0068] A variant which is applicable for both the first and the second embodiment of the bearing housing 1 is to interchange the location of the tongue(s) 62 and the groove(s) 8, meaning that in an analogous manner the tongue or the tongues 62 may be provided at the upper and/or lower housing part 2, 3, in particular at the flanges 24 and 34 on the surface delimiting the opening 7, whereas the groove or the grooves 8 may be provided in the outer rim 61 of the end cover 6.

Claims

1. An axially split bearing housing for receiving the non-drive end of a shaft (110) of a rotary machine (100), the bearing housing extending in an axial direction (A) from an inboard end (41) to an outboard end (42), and comprising an upper housing part (2) and a lower housing part (3) designed for being fixedly connected to each other, and further comprising a disk-shaped end cover (6) for closing the bearing housing at the outboard end (42) in the axial direction (A), characterized in that the upper housing part (2), the lower housing part (3) and the end cover (6) are designed to engage with each other for fixedly connecting the end cover (6) to the upper and the lower housing part (2, 3) in a boltless manner.

2. A bearing housing in accordance with claim 1, wherein the outer rim (61) of the end cover (6) comprises a tongue (62) extending in a radial direction, and wherein the upper housing part (2) and/or the lower housing part (3) comprise a groove (8) for engaging with the tongue (62).

3. A bearing housing in accordance with claim 2, wherein the tongue (62) comprises a notch (63), and wherein the upper housing part (2) or the lower housing part (3) comprise a pin (81) for engaging with the notch (63) to prevent a relative rotational movement between the end cover (6) and the upper and the lower housing part (2, 3).

4. A bearing housing in accordance with anyone of the preceding claims, wherein the outer rim (61) of the end cover (6) comprises a slot (64) for receiving a sealing element, said slot (64) extending along the entire circumference of the end cover (6).

5. A bearing housing in accordance with anyone of the preceding claims, wherein the end cover (6) comprises a centrally arranged hole (65) for receiving a locking device for the shaft (110).

6. A bearing housing in accordance with anyone of the preceding claims, wherein the outer rim (61) of the end cover (6) comprises a plurality of tongues (62) extending in the radial direction, and wherein the upper housing part (2) and/or the lower housing part (3) comprise a plurality of grooves (8), each groove (8) being adapted for engaging with one of the tongues (62).

7. A bearing housing in accordance with anyone of the preceding claims, wherein the upper housing part (2) and the lower housing part (3) each comprise a flange (24, 34) at its respective outboard end, each of said flanges (24, 34) extending radially inwardly.

8. A bearing housing in accordance with claim 7, wherein each flange (24, 34) is integrally formed in one piece with the respective housing part (2, 3).

9. A bearing housing in accordance with anyone of the preceding claims, comprising a first annular chamber (11) for receiving a radial bearing (120) for the shaft (110).

10. A bearing housing in accordance with anyone of the preceding claims, comprising a second annular chamber (12) for receiving a thrust bearing (121) for the shaft (110).

11. A bearing housing in accordance with claim 10, wherein the second annular chamber (12) is delimited by the flange (24) of the upper housing part (2) and by the flange (34) of the lower housing part (3).

12. A rotary machine for acting on a fluid, comprising a shaft (110) having a drive end (111) as well as a non-drive end (112), and further comprising an axially split bearing housing (1) in accordance with anyone of the preceding claims for receiving the non-drive end (112) of the shaft (110).

13. A rotary machine in accordance with claim 12, wherein the rotary machine is a pump, in particular a centrifugal pump (100).

Drawing