High performance centrifugal pump
Technical field
What the present invention relates to is centrifugal pump.
Background technique
Centrifugal pump is mainly by the pump housing; pump cover; impeller; pump shaft; bearing housing constitutes; bearing housing is fixedlyed connected with pump cover by the suspension of its front end; in order to prevent that medium from leaking from pump cover pump end; between pump shaft and pump cover, be provided with mechanical seal device; because the pressure in the pump chamber is very big; so have the mechanical seal device requirement very high to set; as adopt the single mechanical end face seal device; to form a large amount of dielectric leakages in case lose efficacy; though as adopt double end-face mechanical sealing device to improve the reliability of sealing, double end-face mechanical sealing device must be furnished with complicated auxiliary protection system support and use fitting operation; safeguard all very inconvenient, and cost height.In addition, even adopted mechanical seal device still to have a spot of medium can constantly leak into the pump cover opposite side, promptly leak into outside the pump, cause environmental pollution, the leakage environmental pollution of particularly poisonous, inflammable, explosive medium and the influence of safety in production are very big.
Summary of the invention
The purpose of this invention is to provide a kind of good airproof performance, functional good, high pressure resistant, long service life, safe and reliable high performance centrifugal pump.
The pump housing, pump cover, impeller, pump shaft, bearing housing have been the present invention includes, pump shaft is by the installation that is rotatably assorted of bearing means and bearing housing front end and back end, in pump cover inner chamber A, between the preceding perpendicular end face of bearing housing and impeller hub, be provided with mechanical seal device-----Nei mechanical seal device, between bearing housing ear end face and pump shaft, be provided with the outer mechanical seal device of mechanical seal device----, form airtight bearing housing inner chamber B, offer the pressure balance through hole on the perpendicular end face and connection is provided with pressurizer before bearing housing, pressurizer is made of the piston cylinder structure; For further improving the sealability of pump, outside the bearing housing rear end, fixedly connected with pump shaft in the gland of mechanical seal device and be provided with reverse pumping ring, oppositely offer spiral chute on the outer ring surface of pumping ring, oppositely the outer ring surface of pumping ring cooperates the formation volute pump with ring surface in the gland, send the medium pump in the outer mechanical seal device gland inner chamber back to bearing housing inner chamber B, on the preceding perpendicular end face of reverse pumping ring, offer the backflow throttle orifice, to regulate the reversing pump pressurization pressure.Oppositely the pumping ring makes outer mechanical seal device gland inner chamber keep holding the lower pressure of box cavity B relatively, and makes the pressure reduction of outer mechanical seal device seal face both sides less.
The present invention is rational in infrastructure, interior mechanical seal device cuts off pump cover inner chamber A and bearing housing inner chamber B, inside and outside mechanical seal device makes bearing housing inner chamber B form Seal cage, before bearing housing, offer through hole on the perpendicular end face and connection is provided with pressurizer, can make pump cover inner chamber A and bearing housing inner chamber B keep balance, when the pressure of pump cover inner chamber A is big, pass through in the bearing housing inner chamber B that pressurizer-----piston cylinder is delivered to opposite side, be that the piston that the pressure of pump cover inner chamber A promotes pressurizer when big moves to opposite side, make propagation of pressure in the bearing housing inner chamber B of opposite side, make pump cover inner chamber A keep equating with the pressure of bearing housing inner chamber B, because the pressure at interior mechanical seal device seal face two ends equates, almost there is not pressure reduction, so there is not leakage, therefore can adopt the simplest mechanical seal device, and can guarantee sealing and working life, medium in the pump chamber can not leak among the bearing housing inner chamber B, pollution lubricating oil can not mixed to the lubricant oil among the bearing housing inner chamber B.Owing to be provided with reverse pumping ring in the mechanical seal device outside, oppositely promote the pressure of the external mechanical seal device gland of bearing box cavity B liquid inner chamber, oppositely the pumping ring makes outer mechanical seal device gland inner chamber keep the lower pressure of relative bearing housing inner chamber B, make the pressure reduction of outer mechanical seal device seal face both sides less, improved the working environment of outer mechanical seal device, increase the service life, improved sealing.
Good airproof performance of the present invention, long service life, safe and reliable, functional good, adaptive capacity is strong, applicable to higher working pressure, fully satisfies operating mode occasions such as high pressure, poisonous, inflammable, explosive medium and uses.
Description of drawings
Fig. 1 is an embodiment of the invention structural representation.
Fig. 2 is a balace weight structural representation among Fig. 1.
Fig. 3 is a reverse pumping ring structure schematic representation among Fig. 1.
Embodiment
The present invention includes the pump housing 1, pump cover 2, impeller 3, pump shaft 4, bearing housing 5, pump shaft 5 is by bearing means 61,62 with the installation that is rotatably assorted of bearing housing 5 front end and back end, in pump cover 2 inner chamber A, promptly the preceding perpendicular end face 51 of bearing housing 5 and 21 of impeller hubs be provided with mechanical seal device-----Nei mechanical seal device 7, be provided with the outer mechanical seal device 8 of mechanical seal device----at bearing housing 5 ear end faces and 5 of pump shafts, inside and outside mechanical seal device 7,8 make bearing housing 5 inner chamber B form airtight inner chamber, offer pressure balance through hole 52 on the perpendicular end face 51 and connection is provided with pressurizer 20 before bearing housing 5.Outside bearing housing 5 rear ends, fixedly connected with pump shaft 5 in the gland 80 of mechanical seal device 8 and be provided with reverse pumping ring 9, oppositely offer spiral chute 90 on the outer ring surface of pumping ring 9, oppositely the outer ring surface of pumping ring 9 cooperates the formation volute pump with ring surface in the gland 80, offers backflow throttle orifice 92 on the preceding perpendicular end face 91 of reverse pumping ring 9.
The inside and outside mechanical seal device 7,8 of the present invention is single mechanical end face seal devices, or double end-face mechanical sealing device; Be the bellows type mechanical seal device, or spring type mechanical sealing device.
Pressurizer 20 of the present invention is made of the piston cylinder structure; The best structure of implementing is for to be made of piston cylinder 21, bellows 22, piston plate 23, bellows 22 rear and front ends are sealedly and fixedly connected with piston cylinder 21 and piston plate 23 respectively, piston cylinder 21 front ends are connected by the pressure balance through hole of offering on inipple 24 and the perpendicular end face 51 before bearing housing 5 52, and are provided with seal ring 25 on counterface.Its exclusion seal is good, uses reliable.Certainly pressurizer 20 also can adopt other structural type, and as constituting by being provided with spring in piston cylinder 21 inner carrier plates 23 both sides, but its exclusion seal is not as aforementioned structure.
The present invention is provided with coolant jacket 50 on bearing housing 5 housings, form cooling chamber C; Outside mechanical seal device 8 glands 80 outer ends and gland 80 with bearing housing 5 housing seals fixedly connected and be provided with coolant jacket 81, form cooling chamber D; On coolant jacket 50, offer through hole 58, so that two cooling chamber C, D are communicated with.