extjs图表向数字轴添加自定义刻度

Question

我尝试在数字轴的特殊刻度中添加一些文本。我成功完成了以下操作，但是当数字范围较大时，该操作将无效。

var chart = Ext.create('Ext.chart.CartesianChart', {
            itemId:'productionLineProductChart',
            store: this.chartStore,
            animation: !Ext.isIE9m && Ext.os.is.Desktop,
            background: 'rgba(255, 255, 255, 1)',
            insetPadding: {
                top: 10,
                left: 10,
                right: 10,
                bottom: 10
            },
            width: 850,
            height: 300,
            axes: [
                {
                    type: 'category',
                    position: 'bottom',
                    grid: true
                },
                {
                    type: 'numeric',
                    maximum: this.maxChartValue,
                    minimum: 0,
                    position: 'left'
                },
                {
                    type: 'numeric',
                    maximum: this.maxChartValue,
                    minimum: 0,
                    adjustByMajorUnit:false,
                    renderer: function (axis, label, layoutContext, lastLabel ) {
                        var recordData = ...
                        if (label == recordData.get('shiftProduction8'))
                            return '8 hour'
                        else if (label == recordData.get('shiftProduction10'))
                            return '10 hour'
                        else if (label == recordData.get('shiftProduction12'))
                            return '12 hour'
                        else if (label == recordData.get('shiftProduction16'))
                            return '16 hour'
                        else if (label == recordData.get('shiftProduction20'))
                            return '20 hour'
                        else if (label == recordData.get('shiftProduction24'))
                            return '24 hour'


                       return ''
                    },
                    position: 'right'
                }
            ],
   ...
})

我如何禁用默认刻度并添加新刻度？