CN100376780C

CN100376780C - A stirling engine assembly

Info

Publication number: CN100376780C
Application number: CNB2005100840005A
Authority: CN
Inventors: 亚当·理查德·格雷戈里; 大卫·安东尼·克拉克; 朱莉·帕特丽夏·海德; 大卫·迈克尔·热纳维
Original assignee: Microgen Energy Ltd
Current assignee: Micron Energy Holdings; Solarate Ltd
Priority date: 2001-11-14
Filing date: 2002-11-12
Publication date: 2008-03-26
Anticipated expiration: 2022-11-12
Also published as: AR037375A1; KR100964910B1; ATE422025T1; GB0203016D0; DE60231053D1; GB0127375D0; CN1721682A; KR20040052513A

Abstract

A Stirling engine assembly for a DCHP system. A Stirling engine (1) is suspended from a mounting frame (5) by a plurality of tension springs (6). An annular absorber mass (2) surrounds the Stirling engine and is suspended from the engine on a plurality of resilient members (3) arranged asymmetrically about the main axis. The asymmetric arrangement is provided by members of different stiffnesses, or irregular spacing of the members. The absorber mass (2) itself may be reduced adjacent to the resilient members.

Description

Stirling engine assembly

The application is to be that November 12, application number in 2002 are that 02812605.X, name are called the dividing an application of patent application of " Stirling engine assembly " applying date.

Technical field

The present invention relates to a kind of Stirling engine assembly.Particularly, the present invention relates to a kind of assembly that is applicable to domestic combined thermoelectricity (DCHP) unit.

Background technique

Domestic combined thermoelectric unit like this will replace plain cylindrical furnace to be used for family environment.In this case, importantly make noise and vibration keep low-down level, so that client can be accepted.

Normal conditions are to support by motor is installed on the spring, and this spring will be isolated in the vibration that produces in the motor course of normal operation.An example with Stirling engine of this structure is a U.S. Pat 4,400,941.In order to make degree of isolation the highest, need to adopt the installation system of low rigidity.But, adopt low rigidity installation system may cause instability with pressure spring.

Summary of the invention

According to the present invention, a kind of Stirling engine assembly comprises: Stirling engine; Scaffold, motor are installed on this scaffold, and like this, in use, the reciprocating member of motor is along the vertical axis to-and-fro motion, and this motor is hanging on the scaffold by a plurality of extension springs.

By by the spring suspension Stirling engine, rather than it is placed on the spring, employed spring can be the spring of low rigidity, high amount of deflection.Therefore, can eliminate in the prior art contradiction between the requirement of the requirement of stable support and low rigidity installation system.

The spring that hangs motor is particularly suitable for stoping the transmission of low-frequency vibration.In order to improve damping in bigger frequency range, preferably rubber pad and each spring are connected in series.This pad can be arranged between spring and the motor, between spring and the scaffold or in these two positions.These rubber pads are specially adapted to reduce dither.

Preferably, scaffold links to each other with lower half portion of motor.Situation required when linking to each other with motor top with scaffold is compared, and this allows to use long spring.

Has additional radial stability in order to make around the Stirling engine in the suspension structures, and in order to make the combustion zone that appropriate seal be arranged, be positioned on the motor above the dome and housing, that be used for burner can comprise the flexible annular guide on every side, this flexible annular guide is between the inboard bottom surface and motor of this housing.For example, this flexible annular guide is the round section joint ring that is applicable to the material of vibration, hot environment.This will allow to carry out certain transverse movement, and therefore, engine luggine will can not cause damage, and stop the transmission of undesirable power, and can also keep the stability of motor.Also can use the optional sealing configuration that can bear high temperature, high vibration environment.

Preferably, the free length of spring is 100-150mm, and global stiffness is between 0.6 to 0.9kg/mm.When having hung motor, the length of this spring equals the length of engine block ± 20%.

Said structure is a suspension structures particularly advantageous, that be used for Stirling engine.But, by vibration damping structure that is provided with the vibration that can minimize motor and the load that therefore reduces suspension structures, can further improve design.Therefore, preferably, damping block is suspended on below the motor by at least one elastic member, and this damping block is arranged to the power that provides anti-phase with motor.This damping block both can be suspended on below the motor, also can be ring block, thereby around this engine suspension.A kind of structure in back can advantageously provide the Stirling engine with shorter total height.

Under the annular damping block situation of symmetry, because this piece is around the combination about the rotational stiffness of same axis of the inertia of horizontal axis and spring system, the pitching frequency will overlap with vertical frequency.

The pitching degree is relevant with radial rigidity shortage symmetry properties, and the vibration damper piece departs from the spring rate center more, and energizing frequency is approaching more vertical tuned frequency and pitching frequency just.Therefore, elastic member is preferably about the asymmetric layout of the main shaft of annular element.This for example can have different-stiffness to realize by making elastic member.Preferably, be arranged in first spool the opposite side vertical symmetrically, be more preferably, also be arranged in second spool the opposite side vertical with first symmetrically with main shaft with main shaft.

Also can select, be gathered near providing dissymmetrical structure perpendicular to first of main shaft by making elastic member.For this structure, elastic member preferably is arranged to the opposite side symmetry at first.

In both cases, the quality of damping block can reduce with respect to the remaining part place of this damping block near the horizontal axis place of the highest rotational stiffness.

This asymmetric annular vibration damper piece forms an independent aspects of the present invention, and this aspect generalized definition is that a kind of Stirling engine assembly comprises: Stirling engine; Scaffold, motor is installed on this scaffold, like this, in use, reciprocating member is along the vertical axis to-and-fro motion, wherein, the annular damping block is around Stirling engine, and be suspended on the motor by a plurality of elastic members, so that the power anti-phase with motor is provided, this elastic member is arranged to about the main shaft of annular element asymmetric.

According to a first aspect of the invention, when motor passes through spring suspension, when perhaps hanging, can use this structure by some other resilient mounting.

Description of drawings

Introduce an example of Stirling engine assembly of the present invention below with reference to the accompanying drawings, in the accompanying drawing:

Fig. 1 is the schematic sectional view of assembly;

Fig. 2 A is the plan view of a part that comprises the mounting assembly of two springs;

Fig. 2 B is the side view of the structure shown in Fig. 2 A;

Fig. 3 is the schematic sectional view of the optional form of the assembly shown in Fig. 1;

Fig. 4 is the dynamics schematic representation of suspension structures;

Fig. 5 A is the view of the various vibrational modes of the annular damping block of expression;

Fig. 5 B is the view of the axle of expression damping block;

Fig. 6 is the schematic representation of expression first spring structure;

Fig. 7 is the schematic representation of expression second spring structure; And

Fig. 8 is the perspective view that is applicable to the ring block in the structure of Fig. 7.

Embodiment

Stirling engine assembly comprises Stirling engine 1, and this Stirling engine 1 is known in this field.This Stirling engine has displacer and power piston, and this displacer and power piston all are arranged to vertically to-and-fro motion.This has produced the clean vertical vibration of Stirling engine 1 self.

In order to reduce this vibration, vibration damper piece 2 by this above vibration damper piece 2 and below 3 supportings of a plurality of pressure springs.This structure is loaded in the housing 4, and this housing 4 is rigidly fixed in the bottom of Stirling engine 1.This piece 2 and spring 3 are adjusted to like this, and promptly when Stirling engine 1 was worked with normal working frequency, vibration damper piece 2 was as far as possible near vibrate with Stirling engine 1 anti-phasely.Therefore, reduced the overall vibration of Stirling engine 1 and housing 4 greatly.

Current structure is included in 8 pressure springs 3 above the vibration damper piece 2 of 10.5kg (± 10%) and 8 pressure springs 3 below this vibration damper piece 2.For example, the free length of these springs is 67mm, and rigidity is 66.25N/mm (± 10%).This vibration damper is adjusted to the vibration (vibration is minimum when 50.25Hz) that absorbs 48Hz to 52Hz frequency.

The said modules of Stirling engine 1 and housing 4 is installed on the scaffold 5, and this scaffold 5 is around the head of motor, as shown in Figure 1.Motor 1 and housing 4 are suspended on the scaffold around Stirling engine mounting assembly at interval by a plurality of, have represented a kind of such mounting assembly among Fig. 2 A and the 2B.Each mounting assembly comprises a pair of extension spring 6, and this is provided with hook 7 to extension spring 6 in their upper end, be used to be installed in scaffold 5.Second hook 8 is installed on the framework 9 bottom of each spring.

The thickness of Spring Steel Wire is chosen as the weight that is enough to supporting engine 1 and vibration damper piece 2, and the weight of this motor 1 and vibration damper piece 2 still is generally 60kg between 40 to 80kg.At this moment, Spring Steel Wire typically has a diameter from 2.4mm.

Reduce low-frequency vibration for best suspension vibration isolating effect is provided, spring needs long as far as possible, and mounting points should be far away as far as possible in the design allowed band simultaneously.At this moment, top scaffold 5 will just be positioned at the engine burner housing below, bottom motor mount ring 12 be positioned at the bottom engine flange on.At this moment, the length of the spring of elongation is approximately equal to the length (190mm usually) of the engine block of removing cooler 13, heat transfer head 14 and rear end dome 15 (as shown in Figure 1).In addition, must guarantee that the natural frequency (oscillation frequency) of spring does not overlap with operation frequency or its resonance of motor, this may cause unacceptable resonance.

In current structure, be provided with around motor one-tenth rule interval and 6 to 12 springs arranged in pairs (common 8), the free length of this spring is 100 to 150mm (127mm usually) preferably.Total spring rate is (0.75kg/mm usually) between 0.6 to 0.9kg/mm, and in this structure, the rigidity of each spring is generally 0.09kg/mm.

Rubber element 10 is arranged in each framework 9.These rubber element 10 supporting construction bolts 11, by this construction bolt 11, mounting assembly is installed on the installing ring 12 of Stirling engine 1.Therefore, any vibration of Stirling engine 1 all passes to rubber element 10, is delivered in the framework 9 by this bolt 11, passes to scaffold 5 by spring 6 then.

As a kind of possibility, or, can also be provided with rubber element at the top of each spring except the rubber element 10 of each spring bottom.

Rigidity based on each rubber element 10 of four groups of springs is for example 110N/mm.This rubber element is designed to remove high frequency content, and therefore, given rigidity is suitable, and strain remains on proper level, should be kept in mind that the performance of rubber when temperature raises reduces.

Dither will be decayed by rubber element 10, and low-frequency vibration will decay by spring 6, and like this, the vibration that scaffold 5 is subjected to can be ignored, and in the tolerance limit of DCHP unit.

Fig. 3 has represented the optional components of assembly shown in Figure 1.In this structure, housing 4 ' is mounted to around Stirling engine 1, rather than is suspended on as shown in Figure 1 below this motor 1 at this moment, and vibration damper piece 2 ' is an annular, and around Stirling engine.This embodiment requires installing ring 12 that the diameter more much bigger than Fig. 1 arranged.But, the total height of this device reduces, and therefore, this design has useful in limited time in height space.In others, this installs as shown in fig. 1, and same reference numerals is used to represent same parts.

The dynamics figure of this assembly as shown in Figure 4.In the figure, each element is expressed as follows:

M1-master motor piece,

M2-vibration damper piece 2,

The number of the rigidity * extension spring of k1-extension spring 6,

The damping value of c1-and extension spring structurally associated,

The number of the compression stiffness * rubber element of k2-rubber element 10,

The damping value that c2-is relevant with the compressing rubber element,

The number of the rigidity * pressure spring of k3-pressure spring 3 (being generally 16),

C3-is with pressure spring and around the relevant damping value of the air movement of vibration damper piece.

Introduce the version of the annular vibration damper piece of Fig. 3 below with reference to Fig. 5 to 8.

Fig. 5 A and 5B have defined the axle system of ring block.X, Y and Z axle are mutually orthogonal, and wherein X and Y-axis are the horizontal axis in the ring block plane, and they intersect at the center of ring block, and the Z axle is the vertical shaft that stretches out from the center of vibration damper piece 2 '.Intrinsic energizing frequency causes along the up-and-down movement of arrow 20 directions.But, the pitching frequency will overlap with vertical frequency, and this vertical frequency causes the pitching movement about X and Y-axis, shown in

arrow

21 and 22 difference.Annular vibration damper piece is also around the rotation of Z axle, and is as shown in arrow 23.In order to reduce pitching movement around X and Y-axis, proposed to make the asymmetric layout of spring, perhaps make the inertia of vibration damper piece asymmetric.

First example of this set as shown in Figure 6.This structure is suitable for the vibration damper piece usually around the equal situation of the rotary inertia of X and Y-axis.At this moment, vibration damper piece 2 ' has uniform cross section and uniform quality.By spring is arranged to as shown in Figure 6, wherein the rigidity of four springs is K, and the rigidity of all the other four springs is 0.5K, should be understood that, this provides when opposite side symmetry in X and Y-axis of the rigidity of spring the stiffness variation around the periphery of this piece, rather than the stiffness variation of crossing this piece.This spring rate pattern can be on the vibration damper piece with below be made as consistent.In second structure, spring rate and vibration damper piece rotary inertia are all asymmetric.

Second structure as shown in Figure 7, when the rotary inertia of damper rings about X and Y-axis not simultaneously, this second structure is suitable especially.At this moment, provide equal stiffness K ' 8 springs, but they accumulate in the axle X place of high inertia, consistent with the requirement that keeps enough stable in the course of the work.At this moment, provide ring block 2 ", this ring block 2 " substantially the opposite side at it be provided with pair of notches part 25, and these 8 springs be arranged to each above the notch portion and below be installed on the mounting points 26.

Claims

1. a Stirling engine assembly comprises: Stirling engine; Scaffold, motor is installed on this scaffold, like this, in use, reciprocating member is characterized in that along the vertical axis to-and-fro motion, the annular damping block is around Stirling engine, and be suspended on the motor by a plurality of elastic members, so that the power anti-phase with motor is provided, these elastic members are about the asymmetric setting of the main shaft of annular element.

2. assembly according to claim 1 is characterized in that: described dissymmetrical structure provides by the elastic member of different-stiffness.

3. assembly according to claim 2 is characterized in that: these elastic members are arranged in first spool the opposite side vertical with main shaft symmetrically.

4. assembly according to claim 3 is characterized in that: these elastic members also are arranged in second spool the opposite side vertical with first with main shaft symmetrically.

5. assembly according to claim 1 is characterized in that: be gathered near providing dissymmetrical structure perpendicular to first of main shaft by making elastic member.

6. assembly according to claim 5 is characterized in that: these elastic members are arranged to the opposite side at first symmetrically.

7. according to each described assembly in the claim 1 to 6, it is characterized in that: the quality of described damping block is reducing with respect to the remaining part place at this damping block near the elastic member place.